Infection by the novel SARS-CoV-2 coronavirus produces a range of outcomes, with the majority of cases producing mild or asymptomatic effects, and a smaller subset progressing to critical or fatal COVID-19 disease featuring severe acute respiratory distress. Although the mechanisms driving severe disease progression remain unknown, it is possible that the abrupt clinical deterioration observed in patients with critical disease corresponds to a discrete underlying expansion of viral tropism, from infection of cells comprising respiratory linings and alveolar epithelia to direct infection and activation of inflammatory monocytes and macrophages. Dysregulated immune responses could then contribute to disease severity. This article discusses the potential role of monocyte/macrophage (Mo/Mϕ) infection by SARS-CoV-2 in mediating the immune response in severe COVID-19. Additional mechanisms of immune-enhanced disease, comprising maladaptive immune responses that may aggravate rather than alleviate severity, are also discussed. Severe acute clinical worsening in COVID-19 patients may be influenced by the emergence of antibodies that participate in hyperinflammatory monocyte response, release of neutrophil extracellular traps (NETs), thrombosis, platelet apoptosis, viral entry into Fc gamma receptor (FcγR)-expressing immune cells, and induction of autoantibodies with cross-reactivity against host proteins. While the potential roles of Mo/Mϕ infection and immune-enhanced pathology in COVID-19 are consistent with a broad range of clinical and laboratory findings, their prominence remains tentative pending further validation. In the interim, these proposed mechanisms present immediate avenues of inquiry that may help to evaluate the safety of candidate vaccines and antibody-based therapeutics, and to support consideration of pathway-informed, well-tolerated therapeutic candidates targeting the dysregulated immune response. The SARS-CoV-2 coronavirus emerged in late-2019 in Wuhan, China, presenting as pneumonia of unknown etiology. The virus was isolated on January 7, 2020, and its genetic sequence was published 5 days later. Within 10 weeks, the associated disease, COVID-19, was declared a global pandemic by the World Health Organization (WHO). As of December 2020, 65 million confirmed or probable cases of SARS-CoV-2 infection have been identified, with over 1.5 million fatalities  subsets to features observed in patients with severe disease. Potential mechanisms of Mo/Mϕ infection and immune-enhanced disease progression are discussed. “Immune enhancement” in this context refers to maladaptive immune responses that may aggravate rather than alleviate disease severity, beyond cytopathic effects of the virus. Attention is given to the emergence of neutralizing IgG antibodies directed against the SARS-CoV-2 spike, and their potential contribution to hyperinflammatory monocyte response, release of neutrophil extracellular traps (NETs), thrombosis, platelet apoptosis, and antibody-dependent enhancement (ADE) of viral entry into Fc gamma receptor (FcγR)-expressing immune cells. Features of antibody response that may be relevant in the evaluation of vaccine safety are described, including IgG fucosylation, potential generation of autoantibodies with cross-reactivity to host proteins, and interactions of antigen–antibody immune-complexes with Fcγ receptors and components of the complement pathway. Signal transduction pathways, particularly downstream of viral pattern-recognition receptors (PRRs) and FcγRs, are also discussed in the context of immune-enhanced pathology and possible therapeutic modulation.The potential roles of monocyte/macrophage infection and immune-enhanced pathology in COVID-19 are consistent with a broad range of evidence, but their prominence remains tentative pending further validation. In the interim, these proposed mechanisms present specific points of investigation that may be of immediate benefit in the testing of candidate biological interventions. The development of safe and effective vaccines and antibody-based therapeutics relies on evaluation to limit the possibility of immune-enhanced disease. Clinical treatment of active cases may also benefit from the consideration of pathway-informed, well-tolerated therapeutic candidates targeting mediators of the maladaptive immune response.Immune defense against viral pathogens involves the coordination of immediate innate and later pathogen-specific adaptive responses that promote viral recognition, containment, clearance, and host immunological memory. Entry of enveloped viruses such as coronaviruses into host target cells is achieved by binding of a viral surface protein to a receptor protein on the host cell membrane, followed by membrane fusion or endocytosis, and introduction of the viral genome into the host cell. Viral components and genetic material are sensed by host innate PRRs such as Toll-like (TLR), NOD-like (NLR), C-type lectin (CLR), and RIG-I-like (RLR) receptors. Downstream signaling cascades promote the transcription of interleukin (IL)-1, IL-18, Type-I (α/β), -II (γ), and -III (λ) interferons (IFNs), a large set of IFN-stimulated genes (ISGs), inflammatory cytokines such as TNF-α, IL-12, and IL-6, and leukocyte chemoattractants such as CCL2/MCP-1 and CCL3/MIP-1a. These molecules act to impede viral replication, and to recruit cytolytic immune cells such as natural killer (NK) cells and neutrophils, as well as phagocytes such as monocyte-derived macrophages and dendritic cells (DC). Complement proteins contribute to the inactivation of viruses, and phagocytes ingest and present viral antigens, via major histocompatibility complex (MHC) molecules, to cells of the adaptive immune system. These interactions promote expanded populations of pathogen-specific CD4+ T-helper cells, CD8+ cytotoxic T-lymphocytes, antibody-producing B-cells, and T and B memory cells  relative to non-severe cases. Age is a significant risk factor, with a low incidence of symptomatic cases in children and young adults (< age 24). Chronic diseases such as diabetes, hypertension, cardiovascular disease, and chronic obstructive pulmonary disease confer additional risk, although only half of severe cases feature these predisposing factors , 15.Taken together, increasing severity in COVID-19 appears to be associated with a reduction in NK cells, profound lymphopenia, increased proliferation and activation of CD14+CD16+ inflammatory monocytes with reduced antigen-presentation markers, increased cytokine release, elevated acute-phase reactants, and expression of chemokines that mediate the recruitment of inflammatory monocytes, macrophages, and neutrophils to infected tissue.Notably, severe disease cases resulting from infection by the related SARS-CoV (Severe Acute Respiratory Syndrome) and MERS-CoV (Middle East Respiratory Syndrome) coronaviruses feature similar inflammatory infiltrates, elevated cytokine and chemokine release, and respiratory distress marked by diffuse alveolar damage (DAD) .A commonly reported feature of severe COVID-19 is an abrupt deterioration in clinical condition characterized by rapid progression to respiratory distress, with elevation of acute phase reactants and inflammatory mediators resembling those observed in cytokine release syndrome (CRS) and macrophage activation syndrome (MAS)/secondary hemophagocytic lymphohistiocytosis (HLH) . SeveralIt is possible that the abrupt clinical deterioration observed in patients with critical disease corresponds to an expansion of viral tropism, from infection of cells comprising respiratory linings and alveolar epithelia to direct infection and activation of inflammatory monocytes and macrophages (Mo/Mϕ). In the present context, infection of Mo/Mϕ describes viral entry characterized by escape from lysosomal degradation, with a resulting capacity to amplify, inhibit, or otherwise reprogram cellular activities. These potential responses include IFN-independent cytokine/chemokine release triggered by endosomal or intracellular PRRs, transcription of the viral genome, and even support of productive viral replication.Monocytes and macrophages have been demonstrated to mediate the persistence or spread of viruses belonging to 13 different families, including coronaviruses. Mo/Mϕ have high phagocytic activity, and provide an early line of immune surveillance and defense by ingesting and degrading viruses, releasing cytokines in response to PRR signaling, and bridging the innate and adaptive immune system as professional antigen-presenting cells. Viral infection of Mo/Mϕ themselves can provoke alterations in cytokine and chemokine expression, transcriptional response, cell motility, and differentiation to distinct or even simultaneous inflammatory and immunosuppressive polarization. Nikitina et al. provide an excellent review of these mechanisms .Notably, SARS-CoV-2 is capable of directly infecting Mo/Mϕ without cytopathic effect, resulting in significant release of both pro- and anti-inflammatory cytokines including IL-6 and IL-10, with induction of CD163 in CD16-expressing monocytes, and diminished HLA-DR expression . Indeed,ex vivo human lung tissue, SARS-CoV-2 infects type I and type II alveolar pneumocytes as well as alveolar macrophages, with rapid viral replication and significant expression of IL-6, CCL2/MCP-1, and CXLC10/IP-10, yet without significant induction of Type I, II, or III IFNs  and tissues from multiple inflammatory diseases including ulcerative colitis, rheumatoid arthritis, systemic lupus erythematosus, Crohn's disease, and interstitial lung disease. COVID-19 was reported to share two CD14+CD16+ inflammatory macrophage phenotypes with these diseases: one characterized by a CXCL10+CCL2+ cytokine signature, as well as a population expressing the pathogen recognition and complement lectin pathway receptor FCN1/Ficolin-1 . EnrichmDisease severity in COVID-19 is positively correlated with antibody response. Emphatically, this relationship may reflect extensive host–virus interactions in patients with severe disease without implying a pathological role for antibodies. Still, severe disease progression is not reliably curtailed by high production of neutralizing antibodies (NAbs). Rather, severe disease is strongly associated with high levels of NAbs targeting the SARS-CoV-2 receptor binding domain (RBD) located on the trimeric S1 spike (S-RBD). NAbs targeting the S1 spike are reported to be dependent on RBD-specificity for neutralization capacity. Neutralizing antibodies specific to the S2 subunit are also observed in the majority of patient sera. Patients with severe disease generate high NAb titers, while asymptomatic patients may mount little or potentially no NAb response .Based on serial blood sampling, rapid exacerbation of symptoms and progressive lymphopenia among patients with severe and critical disease are observed to coincide with IgG seroconversion, and cannot be explained by uncontrolled viral replication. In contrast, symptoms such as fever, cough, and general malaise are observed to improve in patients with mild and moderate disease prior to or independent of seroconversion .Antibodies with the IgG isotype exhibit the strongest positive association with COVID-19 disease severity. Age and gender  are also significantly correlated with antibody levels . AsymptoThe relationship between neutralizing IgG and severity in COVID-19 mirrors that observed in SARS. In a large-scale prospective study of SARS patients, progression to critical disease generally followed a three-phase pattern. Rapid viral replication during the first week was accompanied by systemic symptoms that gradually receded. During the second week, recurrence of symptoms and severe clinical worsening occurred simultaneously with IgG seroconversion, followed by a third phase of disease progression to acute respiratory distress syndrome (ARDS) and lymphopenia in a subset of critical patients, despite a declining viral load . Virus-sAlthough the correlation between antibody response and disease severity in COVID-19 does not establish a causative relationship, several findings suggest that antibodies to SARS-CoV-2 can participate in maladaptive immune responses. For example, anti-spike IgG from critical COVID-19 patients induces a hyperinflammatory response in monocytes cultured to resemble primary human lung macrophages. In the presence of the synthetic RNA analog poly(I:C), anti-spike IgG triggers exuberant release of IL-1β, IL-6, TNF, and IL-10 from these cells, similar to that observed in COVID-19 patients. Moreover, in the presence of human vascular endothelial cells and platelets under flow conditions, these macrophages disrupt endothelial barrier integrity and provoke microvascular thrombosis . LikewisAs monocytes are susceptible to receptor-mediated infection via surface expression of ACE2 , the potIn a recent study of circulating monocytes isolated from SARS-CoV-2 infected patients presenting for emergency hospital care, 10% of monocytes were infected by the virus, including double-stranded RNA (dsRNA) staining indicative of viral replication, and markers of NLRP3 and AIM2 inflammasome activation. While monocytes derived from healthy donors were inefficiently infected by SARS-CoV-2, pre-incubation with anti-spike antibody or patient plasma was reported to enhance productive infection of monocytes. This effect was abrogated by Ig depletion of patient plasma . MoreoveMonocyte lineages are the primary target of ADE of SARS-CoV infection in the presence of anti-S IgG, and human macrophages are also infected. Antibody-dependent enhancement is dependent on intact intracellular signaling of domains of FcγR, but productive replication of SARS-CoV in infected macrophages is not observed . The cloA central consideration in the evaluation of vaccine safety is the immune response to subsequent viral challenge. SARS-CoV spike-based vaccination of macaques, followed by challenge by live virus, was reported to produce fever 1–5 days after challenge, with 6 of 8 vaccinated macaques developing acute DAD within 1–5 weeks. Control animals demonstrated only mild or moderate inflammation in response to viral challenge. When purified anti-spike S-IgG from vaccinated macaques was administered to healthy animals and followed by viral challenge, all recipients showed acute DAD, with features including hyaline membrane formation, hemorrhage, and infiltration of inflammatory monocytes and macrophages. While SARS-CoV infection of control macaques induced macrophages expressing CD163 and mannose receptor CD206/MR, administration of anti-S-IgG triggered a loss of CD206/MR expression and wound-healing function of macrophages, accompanied by tissue damage and uncontrolled inflammation. Notably, the effects of vaccine-induced immunity can vary markedly depending on the animal model and vaccine design under study, and may depend partly on differences in CD8+ T cell participation and vaccine-induced Th1 response .The molecular mechanism underlying ADE of coronavirus entry was recently described. Wan et al.  demonstrStructurally, the coronavirus spike is comprised of three S1 subunits, each containing a RBD, connected to a trimeric S2 stalk that carries the membrane fusion mechanism. Infection of the host cell first requires cleavage of the viral S1/S2 site by host proteases such as TMPRSS2, followed by cleavage of the S2' site, which liberates viral membrane fusion mechanisms. Binding of the viral RBD to its receptor  stabilizes the bound S1 trimer in a “standing up” position, which is required in order to expose the S2' site to proteasomal cleavage. In antibody-mediated entry, the NAb binds to the tip of the viral spike where the RBD is located, and stabilizes the conformation of the S1 trimer to expose the otherwise inaccessible S2' site to cleavage . BindingIn ADE of SARS-CoV, enhanced entry is pH-independent and minimally affected by inhibition of endosomal proteases such as cathepsin-L, suggesting that entry may occur at the cell membrane, independent of the endocytic pathway . Host ceAntibody-mediated entry of SARS-CoV-2 into human monocyte-derived cells and B-lymphocytes has recently been reported. Antibody-enhanced infection of these cells is mediated by engagement of FcγRII (CD32), with viral fusion occurring at the cell membrane without dependence on endocytosis. Antibody-dependent enhancement is most strongly induced by patient sera derived from elderly donors with severe disease, and is mediated by virus-specific IgG directed against S-RBD . SARS-CoThe potential contribution of ADE in COVID-19 has been discussed in the context of DENV infection, for which ADE has been well-studied , 60. PriInfants with passive immunity from DENV infected mothers typically present with DHF upon initial DENV infection. Strikingly, afucosylation of maternal anti-dengue IgG Fc domains is a highly specific predictor of symptomatic infection in infants, with afucosylated IgG in excess of 10% predictive of severe disease outcomes .Core fucosylation of the IgG Fc domain modifies its binding to Fc receptors, with reduced fucosylation leading to enhanced interactions with the activating CD16a/FcγRIIIa receptor. In symptomatic adults infected with SARS-CoV-2, the Fc domains of anti S-RBD IgG antibodies are characterized by significantly reduced core fucosylation relative to IgG antibodies from healthy adults. Particularly significant reduction in fucosylation of anti-RBD IgG is observed in patients with severe disease, in comparison to patients with mild COVID-19 and asymptomatic children seropositive for SARS-CoV-2 antibodies .Recombinant anti-S IgG derived from patients with severe COVID-19 characterized by low fucosylation promote increased induction of inflammatory cytokines by human macrophages . CriticaImmune-enhanced pathology can include the induction of cross-reactive antibodies against human endothelial cells and molecules involved in platelet function and coagulation, possibly resulting from molecular mimicry by viral proteins having sequence similarities. Such autoantibodies are induced in DHF . InfectiIn patients infected with SARS-CoV-2, the generation of self-reactive antibodies has also been observed –69. The Immune complexes comprised of IgG-bound antigens may further contribute to vascular leakage and cytokine storm via CD16/FcγRIII engagement . Cross-lThus, as is observed in SARS-CoV and MERS-CoV infection, the production of antibodies against SARS-CoV-2 may potentially mediate several forms of immune-enhanced pathology, not limited to ADE, despite contributing to viral clearance. At the same time, these mechanisms suggest specific points of investigation such as ADE, core fucosylation of IgG Fc domains, induction of cross-reactive antibodies, FcγR mediated responses, compliment activation, and related factors that may be useful in evaluating the safety of candidate vaccines and antibody-based therapeutics.Following viral infection of immune cells, viral components such as glycosylated membrane proteins activate signaling by innate pattern recognition receptors, resulting in downstream transcription that may include dysregulated production of inflammatory cytokines and chemokines. For example, repeated activation of the ssRNA sensor TLR7 promotes Mo/Mϕ differentiation into inflammatory hemophagocytes that drive MAS-like disease . NotablyIn MERS-CoV infected monocyte-derived macrophages, upregulation of RLR and CLRs is followed by induction of proinflammatory molecules including IL-6, CXCL10/IP-10, and CCL3/MIP-1a. Depletion of the RLR signaling adaptor MAVS  or spleen tyrosine kinase Syk significantly reduces inflammatory cytokine induction. Induction of Syk by CLR, and downstream activation of NF-κB through the CBM complex (CARD9-BCL10-MALT1) is particularly implicated in the MERS-CoV inflammatory response of macrophages .Signaling by FcγRs depends on downstream signaling by Syk. Activation of PI3K by Syk induces downstream signaling to cytoskeletal proteins that mediate phagocytosis of IgG IC and receptor internalization, while additional signaling pathways promote the expression of pro-inflammatory cytokines and chemokines . The infThe inflammatory response of monocytes in SARS-CoV-2 infection shares numerous features with monocyte response in other viral infections, particularly following activation of innate pattern recognition receptors by heavily glycosylated viruses. For example, Ebola virus (EBOV) infection of monocytes results in strong induction of inflammatory cytokines including IL-6, IL-8, and chemokines CCL3/MIP-1a and CCL4/MIP-1b, with downregulation of class II MHC expression. Recruitment and apoptosis of lymphocytes is accompanied by a marked increase in LDH levels . MonocytLikewise, infection with Hantaan virus (HTNV), which causes uncontrolled inflammatory response and lethal hemorrhage, is associated with a sharp increase in CD14+CD16+ intermediate monocytes, particularly in acute disease. Expression of CD163 in these monocytes is associated with severe disease, with CD206 expression observed more frequently in patients with mild/moderate disease . Viral rThe outcomes of SARS-CoV-2 infection can range from asymptomatic presentation to critical respiratory failure, tissue damage, organ failure, and fatality. Clinical reports suggest that these outcomes do not lie along a smooth continuum, but are often marked by abrupt severe clinical worsening. It is possible that this shift toward poor clinical outcomes corresponds to a change in viral tropism from infection of cells comprising respiratory linings and alveolar epithelia to direct viral infection of immune cells such as monocytes and alveolar macrophages. Although antibody response, inflammation, complement-dependent cytotoxicity, PRR signaling, and Fc-receptor effector functions can contribute to the clearance of viral pathogens, it is possible that these responses may be dysregulated in SARS-CoV-2 infected patients in a manner that contributes to disease severity. The potential roles of Mo/Mϕ infection and immune-enhanced pathology in COVID-19 are consistent with a broad range of evidence, but their prominence remains tentative pending further validation. In the interim, given the global health imperative for the development of safe and effective vaccines and therapeutics, the mechanisms discussed in this article suggest specific avenues of investigation that may be beneficial in the evaluation of candidate interventions.For example, severe lung injury in SARS-CoV infection is not detected in macaques until 7 days following viral challenge , suggestCurrently, the majority of candidate vaccines against SARS-CoV-2 target the viral S protein, including S-RBD . AccordiAs antibodies directed against the SARS-CoV and MERS-CoV S-RBD can functionally mimic the viral receptor and enable transition to a post-fusion conformation , inclusiEven after the development of initial vaccines against SARS-CoV-2, continued research and development efforts will remain important. While the coronavirus S-RBD is highly immunogenic, it is capable of readily generating antibody escape mutations in response to immune pressure . AdaptivThe durability of protection conferred by vaccination against SARS-CoV-2 will likely become an active focus of research. While B-cell responses and NAbs to SARS-CoV decline significantly 1–2 years after infection, induction of memory CD4+ T-cells is suggested to confer more durable protection . As optiIn the event that immune enhancement is observed in a given subgroup in response to viral exposure, such as individuals predisposed to autoimmune or inflammatory response, identification of therapeutic alternatives, and mitigation strategies for at-risk individuals may be beneficial. Such options may include the use of monoclonal antibodies, potentially with Fc-domain mutations to disrupt FcγR crosslinking ; blockadThe original contributions presented in the study are included in the article/supplementary material. Further inquiries can be directed to the corresponding author/s.The author confirms being the sole contributor of this work and has approved it for publication.The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Current cigarette and e-cigarette dual use was associated with 2.15-fold higher odds for reporting COVID-19 infection . Compliance of social distancing behaviors were the lowest for current dual users  and exclusive cigarette users . Conclusions: The findings highlight dual users’ higher prevalence of having COVID-19 symptoms, infection and incompliance of social distancing behaviors. Self-reported infection was associated with dual product use; dual users and exclusive cigarette users were linked to poor adherence to social distancing behaviors. Smoking cessation support and further monitoring on multiple tobacco use among these populations should be reinforced as preventive measures to tackle the pandemic.Introduction: The relationship between current cigarette and electronic cigarette (e-cigarette) dual use, exclusive use and COVID-19-related measures are still unclear. This study aims to assess the association between different tobacco use patterns and coronavirus disease 2019 (COVID-19) symptoms, testing, self-reported infection and social distancing behaviors in the United Kingdom (UK). Methods: Data come from the first wave of the Centre for Longitudinal Studies (CLS) COVID-19 survey, comprising four birth cohorts  surveyed between 2 to 31 May 2020, during the COVID-19 pandemic. Sociodemographic characteristics and COVID-19-related outcomes  were compared across different product user groups  using Cochran–Mantel–Haenszel χ2 test. Multivariable logistic regression models were used to explore associations between COVID-19-related outcomes and different smoking patterns. Results: Across all four cohorts, 12.6% and 4.9% of the respondents were current exclusive cigarette and e-cigarette users, respectively, with approximately 3% of the respondents being dual users. Significant differences in prevalence were observed between different tobacco use patterns and COVID-19 symptoms ( Smoking is a leading cause of premature death and is a well-established risk factor for a myriad of acute and chronic diseases that affect cardiovascular and respiratory systems . The corResults from systematic reviews and meta-analyses of existing studies suggest an association between smoking and a greater risk of COVID-19 disease progression, severity, and mortality ,4,5,6,7.The results seen in smokers further raise speculations of whether this also applies to people who use e-cigarettes, vaping products or dual users of both cigarettes and electronic cigarette (e-cigarette) . SufficiA recent cross-sectional study among a national sample of US adolescents and young adults found that dual users of both cigarettes and e-cigarettes within the past 30 days were more likely to report experiencing COVID-19-related symptoms . HoweverHowever, the relationship between dual tobacco product use and risk of COVID-19 infection is less clear . The aimData come from Wave 1 of the University College London Centre for Longitudinal Studies (CLS) COVID-19 study, a series of surveys following large nationally representative cohorts of people on COVID-19-related outcomes during the COVID-19 pandemic. The CLS COVID-19 survey was administered online to participants across four nationally representative cohorts, each representing a different generation of the UK population. The details of the survey design, recruitment procedure, and survey process have been described elsewhere [The analytic sample of the current study include data from four cohorts managed by CLS: The Millennium Cohort Study, born in 2000–2002, aged 18–20 (n = 2403); Next Steps, born in 1989–1990, aged 31 (n = 1780); the 1970 British Cohort Study, born in 1970 aged 51 (n = 4022); and the National Child Development Study, born in 1958, aged 63 (n = 4872). Overall, the sample included 13,077 respondents aged 20–63 years old.The respondents self-reported their sociodemographic characteristics , and current tobacco use pattern  at the time of the survey. Cigarette/e-cigarette use, or dual use were assessed by reporting current occasional or daily use of cigarettes and/or electronic cigarettes.The socioeconomic class was categorized into high, intermediate, and the lower three distinctive groups, according to the respondents’ socioeconomic status prior to the COVID-19 pandemic (so that is not affected by recent job loss or lockdown restrictions), using the 2010 National Statistics Socioeconomic Analytical Classes (NS-SEC) [We compared different tobacco use patterns by participant characteristics and COVID-19-related measures within and across cohorts using the Pearson’s χ2 and Cochran–Mantel–Haenszel χ2 test, respectively. Multivariable logistic regression models accounting for sample survey weights were used to explore associations between COVID-19-related measures and different smoking patterns. The primary sampling unit and strata were also accounted for by the stratified survey designs within cohorts. Models were adjusted for sex, socioeconomic class, self-rated health, chronic illness and cohorts. Adjustment was made for survey non-response weight calculated by the CLS team [p < 0.05). A higher proportion of dual users were male (54.7%) compared to females (45.3%). Among those with reported socioeconomic class, the proportions of dual users were found to be higher among those with lower socioeconomic class (34.9%) compared to those with higher socioeconomic class (19.1%). A higher percentage of non-users self-rated their health as “excellent” (15.9%) compared to all cigarette and e-cigarette user groups; whereas the proportion of those reported “poor” health were highest among exclusive cigarette users (5.0%) and dual users (3.8%). Compared to non-users (48.6%), exclusive cigarette users, e-cigarette users and dual users reported a higher prevalence of chronic illness .Among the overall sample, all participant characteristics varied significantly by tobacco use patterns (p = 0.02), diagnosis (p = 0.04) and social distancing behaviors (p < 0.001), with the proportion of dual users higher than that of other smoking pattern groups across all cohorts. In the overall sample, dual users had the highest percentage reporting COVID-19 infection (14.8%) and COVID-19-related symptoms (13.2%) in the past two weeks, compared to all other tobacco use groups. Reported adherence to social distancing was significantly lower among dual users (42.8%) and cigarette users , as compared to non-users (56.9%).Significant differences were also observed between different tobacco use patterns and COVID-19 symptoms  and COVID-19-related measures during the early period of the pandemic. We further assessed the association between different tobacco use patterns and COVID-19 symptoms, testing, self-reported infection and social distancing behaviors in the UK.There were significant differences between tobacco use patterns and all participant characteristics across all cohorts. The overall prevalence of current dual users was higher among male, having lower socioeconomic class, poorer self-rated health and higher prevalence of pre-existing condition compared to non-users. Additionally, similar to previous findings, tobacco users were found to have significantly higher percentages for experiencing COVID-19 symptoms, self-reported COVID-19 infection and lower adherence to COVID-19 protective behaviors ,21. HoweThe observed gradients in occupational social class and self-reported health among tobacco users suggest the inequality of smoking during the pandemic. This may be of particular relevance in the context of COVID-19 and dual product user, as evidence suggests increased vulnerability to the virus among tobacco product users ,5 and thFurthermore, multivariable logistic regression models revealed that dual users were associated with over two-fold higher odds of confirmed or suspected COVID-19 diagnosis, and decreased odds of compliance of social distancing by a quarter for exclusive cigarette users and a half for dual users, compared to non-tobacco users. Heightened odds of self-reported COVID-19 infection among dual tobacco users could be due to the fact that dual users were exposed to elevated levels of nicotine and toxicants via cigarette smoking and vaping, which adversely affects lung function ,14, thusAssessments regarding tobacco use status in the emerging pandemic is challenging as the methodology used to classify smoking status in studies may not be nuanced enough to capture status change between recent quitters/former smokers and non-smokers. Thus, any former smoking/vaping behavior, which could be associated with COVID-related outcomes, would not have been captured by the measurement of current smoking/vaping status.Our findings that smokers and dual users self-reported lower adherence to social distancing suggest that being a smoker can make social distancing more challenging . This asThere is limited and contradictory evidence on the association of tobacco use with adverse outcomes of COVID-19 infection . Our stuOur findings from nationally representative birth cohorts highlight dual users’ higher prevalence of having COVID-19 symptoms, self-reported infection and incompliance of social distancing behaviors. Significant associations of COVID-19 infection with dual product use, and that dual users as well as exclusive cigarette users were linked to poor adherence to social distancing behaviors. As mounting evidence suggests tobacco product use is strongly associated with COVID-19 infections and progressions, smoking cessation support and further monitoring on multiple tobacco use should be reinforced as preventive measures to tackle the pandemic.


Following a comprehensive and systematic search of the available literature, 87 relevant papers spanning the years 2005 to 2021 were identified. This review aims to provide and update an overview of lncRNAs in AKI, and further shed light on their potential utility as AKI biomarkers and therapeutic targets.Acute kidney injury (AKI) is a global public health concern with high morbidity, mortality, and medical costs. Despite advances in medicine, effective therapeutic regimens for AKI remain limited. Long non-coding RNAs (lncRNAs) are a subtype of non-coding RNAs, which longer than 200 nucleotides and perform extremely diverse functions in biological processes. Recently, lncRNAs have emerged as promising biomarkers and key mediators to AKI. Meanwhile, existing research reveals that the aberrant expression of lncRNAs has been linked to major pathological processes in AKI, including the inflammatory response, cell proliferation, and apoptosis,  Acute kidney injury (AKI) is a severe clinical syndrome characterized by an abrupt decrease in kidney function, as measured by high blood creatinine and decreased urine volume within 7 days . EpidemiEven though our understanding of the pathophysiology of AKI is continually expanding, the precise processes remain unknown. Following the improvements and cost reductions of high throughput RNA-sequencing, considerable research has reported that the non-coding RNAs (ncRNAs), especially long non-coding RNAs (lncRNAs), are strongly associated with the pathophysiological process underlying AKI. As the quantity of research on lncRNAs has grown fast, in order to offer a thorough and up-to-date overview of the function of lncRNAs in AKI, we briefly introduce the lncRNA and systematically review the mechanism of functional lncRNAs in AKI due to various etiologies. Finally, we highlight certain aspects of the lncRNA mechanism in AKI, as well as future research directions.LncRNAs are a subtype of ncRNA that longer than 200 nt with no protein-coding potential and make up the most considerable portion of the mammalian non-coding transcriptome . SequencMost lncRNA species are transcribed by Pol II. It also could be capped, spliced, and polyadenylated, exported like mRNA. However, after being transcribed by Pol II, lncRNAs will further fold into the complex secondary or tertiary structures. Those high-ordered structures showed higher conserved than their primary sequence. Diversified structure enables lncRNAs to participate in life activities and disease progress by interacting with DNA, RNA, or protein to regulate gene expression at multiple levels . Among these, research on the roles of lncRNAs in post-transcriptional regulation has been investigated the most. Three major mechanisms of lncRNA regulate the gene expression in post-transcriptional: a. binding to RNA or structures to form a lncRNA-protein complexes directly; b. pairing with the other RNAs to recruit proteins; c. competing endogenous RNAs or ‘sponges’ of miRNAs to restrict miRNA availability to target mRNAs . Aside fin situ hybridization (FISH) offer great assistance in annotating the characteristic of lncRNAs, such as coding potential, location information on the genome, secondary structure, correlation with the diseases, full-length analysis, and cell localization  in LPS induced AKI. Correspondingly, silencing MALAT1 displayed a significant renal protective effect  in sepsis-induced AKI. Depletion of NEAT1 could attenuate sepsis-induced AKI  pathway . Further pathway . siNEAT1ll death . MoreoveAK1 axis .via miR-17-5p, accompanied by improved cell viability and reduced inflammatory response (Another lncRNA plasmacytoma variant translocation 1 (PVT1) has also gained much attention. Suppression of PVT1 in LPS-treated HK-2 cells could inactivate the NF-κB pathway response . Besidesresponse . Additioresponse . The lncresponse .Similar to the regulatory network between lncRNAs and miRNAs mentioned above, the connecting as follows could also play a role in promoting cell apoptosis or inflammation response in septic AKI by sponging the related miRNA, TapSAKI/miR-22/PTEN/TLR4/NF-κB , TapSAKIvia mediating the PI3K/AKT pathway  expression decreased in a time-dependent manner, and GAS5 inhibition promoted podocyte injury by inhibiting the expression of PTEN  pathway .Contrary to the abovementioned studies, many expressions decreased lncRNAs could also participate in critical pathophysiological processes in septic AKI. PlncRNA-1 was downregulated in the serum of patients with septic AKI and LPS-induced cells. PlncRNA-1 overexpression relived kidney injury by increasing proliferation and inhibiting apoptosis and autophagy in LPS-treated cells . LncRNA via modulating miR-687/PTEN signaling  was shown to have anti-inflammation and pro-survival effects in LPS induced renal tubular epithelial cell damage uced AKI . A recenuced AKI .via increasing miR-181a-5p  expression in HK-2 cells and mice. CRNDE inhibition could reduce sepsis-induced kidney injury by blocking the activation of the TLR3/NF-κB pathway . Meanwhi-181a-5p . Another-181a-5p . However-181a-5p .Ischemia–reperfusion is one of the leading causes of AKI. Inflammation and oxidative stress are the most common processes involved in the pathogenesis of renal I/R injury. Zhou and coworkers profiled the lncRNA expression pattern in the kidney of AKI mice by second-generation gene sequencing. They reported 90 differentially expressed lncRNAs which included 20 up-regulated and 70 down-regulated. These dysregulated lncRNAs participated in multiple biological processes, including stimulus response, multicellular organismal processes, single-multicellular organism processes, and so on . In 2017Studies have been conducted to determine if lncRNAs are implicated in I/R-induced AKI . HypoxiaIn vitro experiments, the lncRNA SNHG14 could mitigate I/R-induced kidney injury via competition with miR-124-3p to regulate the expression of MMP2 in HK-2 cells (via binding with the RNA-binding protein Hu antigen R (HuR) and regulation of ATG7/16 L1 expression , also called contrast-induced acute kidney injury (CI-AKI), is a kind of kidney disease that the renal function deteriorates suddenly within 48 h of intravascular administration of contrast medium . Data haSince the expression of lncRNAs has undergone massive changes in PC-AKI, more and more researchers are delving into the specific regulatory mechanism that lncRNA is involved in PC-AKI. Cheng and coworkers systematically explored the lncRNA-associated-ceRNA regulatory network in rats with PC-AKI by RNA-seq analysis and two constructed ceRNA regulatory pathways in the CI-AKI rat model (novel_circ_0004153/rnomiR-144-3p/Gpnmb or Naglu and LNC_000343/rno-miR-1956-5p/KCP) were reported firstly and validated by real-time qPCR. Further function annotation shows that the disease-specific lncRNAs may participate in physiological and pathological processes of PC-AKI from different aspects, including porphyrin-containing compound metabolic, biosynthetic processes, heme binding, and so on . AnotherKidney transplantation is one of the effective treatments for patients with end-stage renal disease (ESRD). However, as a potentially severe complication, post-transplant AKI still maintains high morbidity and mortality rates . The patIn 2013, Sui et al. integrated protein array-based proteomics and RNA microarray-based genomics to investigate the transcription factors (TF), miRNAs, long noncoding RNA of biopsies of three patients with acute rejections. They discovered that among the 32 differentially expressed lncRNAs, FXYD1 and HOXA11 were targeted individually by the lncRNAs Uc002nyb and Uc003syy, which were linked to a poor outcome in acute rejections . Anothervia the downregulation of miR-200c . The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. 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Genome-wide association studies have successfully mapped thousands of loci associated with complex traits. During the last decade, functional genomics approaches combining genotype information with bulk RNA-sequencing data have identified genes regulated by GWAS loci through expression quantitative trait locus (eQTL) analysis. Single-cell RNA-Sequencing (scRNA-Seq) technologies have created new exciting opportunities for spatiotemporal assessment of changes in gene expression at the single-cell level in complex and inherited conditions. A growing number of studies have demonstrated the power of scRNA-Seq in eQTL mapping across different cell types, developmental stages and stimuli that could be obscured when using bulk RNA-Seq methods. In this review, we outline the methodological principles, advantages, limitations and the future experimental and analytical considerations of single-cell eQTL studies. We look forward to the explosion of single-cell eQTL studies applied to large-scale population genetics to take us one step closer to understanding the molecular mechanisms of disease. Any eQTLs lying outside this genomic window are thought to indirectly regulate gene expression and are considered trans-eQTLs . Th. Th11]. +, HOXC6+, ATF1+, TEAD2+, KLF10+ and RXRB+) and iPSCs into four types . In addition, single-cell cis-eQTLs were mapped in six fibroblast cell lines as well as four iPSC lines that were derived from the same participants. Collectively, they identified 46,103 eQTLs in 2985 genes representing 45,503 eQTLs for 2887 genes found in fibroblast cell types and 810 cis-eQTLs for 86 genes in iPSC derived cell types. Importantly, the majority of eGenes were predominantly cell type specific and only identified in only one fibroblast type (77.6% of fibroblast eGenes) or one iPSC type (97.2% of iPSC eGenes). Furthermore, the majority of the 283 eGenes that were significant in multiple cell types including the 14 eGenes that overlapped between fibroblasts and reprogrammed iPSCs, were found to be regulated by different genetic loci. A comparison with bulk RNA profile from GTEx cultured fibroblasts [A reverse approach to iPSC differentiation recently evaluated the allelic effects of iPSC reprogramming from fibroblasts on single-cell gene expression . Here, hroblasts  showed ocis-eQTLs in 1294 genes across different cell types. A cis-eQTL comparison with parental scRNA-seq dataset revealed 870 genes that were differentially expressed; 23% of these had a cis-eQTL in the same tissue and 95% of cis-eQTLs had same direction of effect as parental. An overlap with a previously published bulk RNA-seq [cis-eQTLs, 335 were shared between two studies and had correlated effect sizes ; 50% of the eGenes detected in multiple cell types were also identified in bulk and 28% of the eQTLs were detected in a single cell type. Finally, a cell type specific analysis of C. elegans nervous system reveled 12,647 neurons in 81 distinct clusters. 163 cis-eQTLs and 132 eGenes were identified where 88% were cell-type specific. In a pan-neuronal cis-eQTL analysis, 36 of 69 (52%) eQTLs had opposing direction to cell-type-specific eQTLs, confirming a subtype-specific effect. For example, nlp-21 had significantly opposing effects in RIC interneurons and ring interneuron/motor neurons, but no significant effect was found in the pan-neuronal dataset. In conclusion, this study provided direct evidence that the sc-eQTL mapping improves the power to detect cell-type-specific effects but also effects that are specific to subtypes of cells. Although this study was the first one to utilize scRNA-seq in whole-organism eQTL mapping, its applicability in more complex higher organisms could be limited.scRNA-seq has made it possible to sequence many cells simultaneously, analyze cell-type-specific genetic architecture and compare it among different cell types to evaluate how genes regulate the fate of a cell into a particular type. Keeping this as a goal, Ben-David et al. , piloted RNA-seq  dataset cis-eQTL studies. The authors concluded that statistical power of cell-type-specific eQTL mapping can be maximized by increasing the sample size (~100) and the number of cells per sample while performing low-coverage sequencing of 10,000 reads per cell [The first pioneering studies outlined above have clearly demonstrated the advantage of scRNA-Seq in identifying cell-type- and cell-state-specific eQTLs. Still, many of these studies demonstrated limited power for eQTL mapping due to lower sample numbers that are largely imposed by the high cost of scRNA-Seq experiments . This liper cell . They fuper cell ,35,36. Cper cell . Additioper cell . Neverthcis-eQTL analysis and understanding patterns of human disease and development.Another limitation of the scRNA-Seq studies comes from the library configuration. Most of the studies thus far have used the 10× Genomics Chromium platform that sequences the 3′- or 5′-end of mRNA and does not allow the identification of splicing QTLs for isoform detection or deep intronic QTLs. These issues can be addressed by the full-length sequencing approaches such as SMART-seq  which, hcis-eQTL associations in the future.High technical noise in scRNA-seq data is still a challenge. It arises due to a difference in sequencing platform, sequencing depth, amplification bias, RNA capture efficiency and dropout events. Current noise reduction methods for scRNA-seq data include correcting for batch effect and normalization of the sequencing data. A recent study comprehensively analyzed 28 noise-reducing methods and tools in 55 scenarios comprising of real and simulated datasets and proposed a guideline to select suitable procedures . The stuFinally, only a limited number of studies have reported scRNA-seq for eQTL analysis in human disease and development ,11 indicAs discussed above, scRNA sequencing has created immense opportunities for mapping eQTLs across different cell types, developmental stages and stimuli that could be obscured when using bulk RNA-Seq methods. By decreasing the measurement noise that is introduced due to heterogeneity of cells in bulk RNA profiling, identification of eQTLs associated with rare cell types and specific cell states, including developmental stages, stimulus responsive states and cell cycle phases, can be achieved. In addition to the ability to distinguish the cell-type-specific transcriptome features, scRNA-seq studies have shown great potential for identification of gene regulatory networks and gene–gene interactions and co-regulated genetic features . Moreove


The onset of the SARS-CoV-2 pandemic has resulted in ever-increasing casualties worldwide, and after 15 months, standard therapeutic regimens are yet to be discovered.Due to the regenerative and immunomodulatory function of MSCs, they can serve as a suitable therapeutic option in alleviating major COVID-19 complications like acute respiratory distress syndrome. However, the superior properties of their cognate exosomes as a cell-free product make them preferable in the clinic. Herein, we discuss the current clinical status of these novel therapeutic strategies in COVID-19 treatment. We then delve into the potential of interfering RNAs incorporation as COVID-19 gene therapy and introduce targets involved in SARS-CoV-2 pathogenesis. Further, we present miRNAs and siRNAs candidates with promising results in targeting the mentioned targets.Finally, we present a therapeutic platform of mesenchymal stem cell-derived exosomes equipped with exogenous iRNAs, that can be employed as a novel therapeutic modality in COVID-19 management aiming to prevent further viral spread within the lung, hinder the virus life cycle and pathogenesis such as immune suppression, and ultimately, enhance the antiviral immune response. As of December 2020, roughly 67 million confirmed cases with severe acute respiratory syndrome coronavirus 2 (SRAS-CoV-2) infection had been reported, with over a million and a half demises . In respAlthough gene transfer-based approaches have been singularly exploited in vaccine design and multiple candidates are now under clinical evaluation , except Exosomes collected from several cell types have shown promise in inducing remission in virally infected patients, especially SARS-CoV-2 positive individuals , 4. MultThis article reviews the current status of exosome-based therapies, particularly those derived from MSCs and their promise as genetic material-delivery vectors. The MSCs’ immune-modulatory and regenerative capabilities in alleviating pulmonary complications, specifically COVID-19, are then elaborated, serving as a rationale for their assignment as the exosome source. Afterward, we delve into the ongoing clinical studies on the administration of exosomes on COVID-19 treatment. Thereafter, the promise of RNA interference (RNAi) -based gene therapy for COVID-19 is explained.Then, the potential interfering RNA candidates and their cognate targets are introduced in four classes, pro-viral microRNAs (miRNAs), the viral genes themselves, host genes mediating the virus entry and replication, and those of hosts playing roles in the induction of hyper-inflammation.We culminate by depicting a pipeline for the administration of MSC-derived secretomes carrying a cocktail of the mentioned iRNAs as a novel therapeutic approach for COVID-19 patients in critical status.Upon its entry into the lung through respiration, SARS-CoV-2 primarily invades and destroys pulmonary epithelial cells. The released viral molecular structures are then recognized via pattern recognition receptors (PRRs) on lung-resident innate immune cells, including dendritic cells and macrophages. The local immune response is then triggered, and inflammatory cytokines and chemokines are produced, attracting other immune cells, including T lymphocytes and monocytes. Under normal circumstances, the subsequent anti-viral immune response wipes out the virus with minimal damage before its extensive spread throughout the body. However, the aberrant hyper-inflammatory response in some individuals results in a sudden release of an excessive amount of pro-inflammatory cytokines, a process known as “cytokine storm” –7. CumulMSCs are well known for their profound performance in immunomodulation and tissue repair when encountering a highly-inflamed milieu, particularly in the lung. These cells exert their immunomodulatory and reparative impacts either via direct cell–cell interaction or through the paracrine release of the underlying mediators, including the cell’s migratory elements, immune regulatory agents, antiapoptotic factors, and angiogenic mediators –15.They shift the immune system status from inflammation toward regulatory mode by suppressing T lymphocytes’ proliferation and converting the balance between Th1 inflammatory cells and T regulatory cells toward the latter , 17. TheFollowing modulating the immune response within the lung, they instigate the regeneration of the injured tissues through reversing lung dysfunction and halting pulmonary fibrosis . These dAlthough the safety and efficacy of MSC-based treatment are demonstrated by a handful of studies, the possibility of SARS-Cov-2 infection on MSCs was unknown. Recently a study conducted in china illustrates that the ACE2 and TMPRSS2—the two vital receptors for viral entry—are not expressed on MSC cells, and injection of MSC has no role in inducing infection of other cell types . The resDespite its tremendous benefits, utilizing MSCs as immunomodulatory and regenerative agents is not devoid of limitations, particularly when administered through the IV route . For exaAfter almost three decades since the first report , exosomeSecreted exosomes containing biologically active macromolecules can deliver their cargo to the target cell by two distinct mechanisms. First, following the selective binding to cell surface receptors, exosomes are thought to transduce specific intracellular signaling, thereby inducing physiological changes in recipient cells . The secFrom the pharmaceutical aspect, exosomes demonstrate therapeutic potential when utilized in their native form. For instance, exosomes originated from stimulated platelets have demonstrated superior efficiency in occlusive thrombosis suppression . FurtherThe present pandemic renewed many researchers' interest in the applicability of exosomes as an effective and safe therapeutics for combating COVID-19 associated diseases. As of November 2020, seven clinical trials have been submitted on clinicaltrials.gov to evaluate the safety and/or efficacy of exosome-based therapeutic regimens on SARS-CoV-2 positive patients  were administrated to severe patients afflicted with SARS-CoV-2 pneumonia through aerosol inhalation (NCT04276987). Although the study was reportedly completed in July 2020, the results are yet to be published. In another ongoing parallel clinical study on healthy volunteers, Rujin Hospital evaluates the safety and tolerance and determines the clinical dose reference for the aerosol inhalation of the exosomes mentioned above (NCT04313647).d-dimer .Fig.Fig66].FSARS-CoV-2 genome has 14 open reading frames (ORFs) and encodes 27 proteins, of which four are structural, an envelope protein (E), Nucleocapsid protein (N), matrix protein (M), and spike protein (S). Fifteen non-structural proteins (NSPs) within the ORF1a and ORF1b regions are located at the 5′ end of the genome, and the 3′ end of the genome comprises the sequences pertaining to eight accessory proteins and structural proteins . The regDesigning siRNAs is a versatile process, and multiple siRNA designing approaches exist and have been reviewed elsewhere . SeveralWhen designing siRNAs, it is worth considering that following SARS-CoV-2 entry to the cell, the positive-sense, single-stranded genomic RNA is translated into viral polymerase proteins. Subsequently, the complementary negative-sense RNA is synthesized and the regions encoding the structural proteins, and some accessory proteins begin to serve as a template for viral mRNA transcription , 79. TheAccordingly, the virus’s various genome loci are differently present in the host and hence will be targeted disproportionately. Genes within the first 20 kb portion of the virus’s genome are present in two forms, positive and negative sense strands. This portion holds the sequences of ORF1a and ORF1b, and designing a siRNA against the sequence within these loci would theoretically lead to the viral genome double-targeting. With respect to the 10 kb of the genome at the 3′ end, the negative and positive sense strands alongside the viral mRNAs could be triple-targeted via both siRNA strands, yielding a higher viral propagation inhibition . HoweverIFNB as well [Human miRNAome has been exhaustively explored to select miRNAs with prospective potential against the virus genes. Of the human miRNA repertoire, seven miRNAs were predicted to target and inhibit SARS-CoV-2 genes, including N . In a st as well .Numerous studies have discovered viral miRNAs and pro-viral human miRNAs contribution to virus pathogenesis, some of which shedding light on their ablation via anti-miRNA oligonucleotides. Anti-miRNA oligonucleotides are synthetic oligonucleotides neutralizing miRNAs of interest . ComputaThe number of identified host genes and pathways involved in viral entry, replication, and pathogenesis is on the rise, and their targeting has been introduced as a therapeutic intervention for COVID-19. Numerous studies are evaluating their perturbation to identify proteins and pathways exhibiting antiviral impacts.Viral entry is mediated via membrane-bound ACE2 protein binding on lung cells, and its presence on infected cell surface declines due to endocytosis with the viral particle, and this event participates in the disease’s pathogenesis. Although it may seem like an exciting candidate, its knockdown accompanies serious side effects , 91. NonFurin, namely paired basic amino acid cleaving enzyme (PACE), is another PC and mediates the exposure of S protein binding and fusion domains and is indispensable for the virus entering the cell. Inhibition of furin may have a therapeutic potential via blocking viral entry in SARS-CoV-2 and other viruses that possess the furin cleavage domain. Furin protein inhibitors demonstrated promising outcomes in various pathogens disease models, including influenza A virus, Pseudomonas aeruginosa, and HIV. GM-CSF bi-shRNA furin plasmid (VP) carries two short hairpin RNAs (shRNAs) against furin is now under clinical evaluation for Ewing’s sarcoma and ovarian cancer and is proposed as a repurposing drug for inhibition of viral propagation and immune response promotion , 96.In a genome-wide CRISPR-based screening assay, Wilen et al. identified Cathepsin L, a mediator of viral entry through endocytosis , the SWIThe possibility of the iRNAs’ efficacy against the mentioned genes as COVID-19 therapy is yet to be assessed, and to our knowledge, only one study has been conducted from this perspective. Seven candidate miRNAs were revealed in a study by Ramakrishnan and colleagues to target host-encoded proteins in signaling pathways involved in receptor activation and host protein hijacking machinery during the pathogenesis of SARS-CoV-2 .Anti-miRNA oligonucleotides can also be designed to target the host miRNAs that assist viral pathogenesis. SARS-CoV-2 infection-induced human miRNAs are found to downregulate multiple pathways in antiviral defense response, including different Toll-Like Receptors (TLRs) .d-dimers as a result of pro-inflammatory cytokines increase [One of the clinical manifestations of COVID-19 is viral-induced inflammation, leading to ARDS. This syndrome is preceded by a significant rise in inflammatory parameters, such as C-reactive protein (CRP) levels, serum ferritin, the erythrocyte sedimentation rate, and increase .Inflammation generally consists of four steps, stimuli recognition by PRRs, inflammatory pathways activation, the release of inflammation mediators, and recruitment of immune cells to the inflammation site. Upon binding damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs) to PRRs like TLRs and nod like receptors (NLRs), transcription factors within multiple inflammatory pathways including nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and the Janus kinase signal transducer and activator of transcription (JAK–STAT) pathways translocate into the nucleus and upregulate the expression of various inflammatory cytokines and chemokines. A handful of inflammatory elements such as CRPs, high mobility group box protein 1 (HMGB1), superoxide dismutase (SOD), glutathione peroxidase-1 (GPx), NADPH oxidases (NOX), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (Cox-2) are released from the afflicted cells and promote inflammation through their binding to inflammatory receptors . Myriad Cox-2 synthesizes prostaglandins in response to cytokines and mediates inflammation and tissue damage. Its promoter contains regulatory response elements to NF-kB and IL-6, and SARS-CoV N protein has been previously shown to induce its expression , 105. AlDespite lack of experience in iRNA-mediated Cox-2 silencing in COVID-19, its knockdown and subsequent inflammation modulation have been vastly investigated for other diseases, including cancer and hepatic fibrosis. In a comprehensive review by Espisni et al., lists of studies analyzing various siRNAs and miRNAs are provided , 108. InOf the MAPK signaling groups, the p38 MAPK pathway is aberrantly upregulated during SARS-CoV-2 infection, leading to the production of pro-inflammatory cytokines such as IL-6, TNF-α, and interleukin 1 beta (IL-1β). Multiple clinical studies are evaluating p38 inhibitors for a variety of complications . NumerouSeveral miRNAs have also demonstrated efficacy in downregulating p38 and can serve as therapeutic candidates. In an attempt to reveal the mechanisms of action of three antiviral miRNAs, miR-124, miR-24, and miR-744, p38 was identified as a ubiquitous antiviral target in multiple viral infections, including influenza and respiratory syncytial virus (RSV) infection . In an eNF-kB has repeatedly been demonstrated to orchestrate inflammation and contribute to inflammation-consequent pulmonary complications, including ARDS . NF-kB iAs a significant regulator of numerous inflammatory cytokines and chemokines, targeting NF-kB transcription factors inhibits multiple pro-inflammatory cascades simultaneously, serving as a superior therapeutic candidate. Cumulating evidence pinpoint the potential of NF-kB suppression in coronavirus-mediated SARS treatment as NF-kB inhibition in SARS-CoV animal models increased its survival and decreased pro-inflammatory agents’ expression . The preA manifold of siRNAs is designed and proven to effectively downregulate NF-kB or members of NF-kB signaling pathway and subsequently reduce expression of the NF-kB-regulated genes associated with inflammatory pathways in various pulmonary settings, including sepsis-induced acute lung injury in mice models, lipopolysaccharide-induced acute lung injury in rat models, lung cancer cells –128.A myriad of miRNAs has been discovered which down-regulate the NF-kB pathway in various organs and modalities. Several papers listed the major miRNAs with altered expression levels in cancer with an impact on this pathway, some of which can serve as therapeutic candidates , 130. CoIt has long been established that interfering RNA-mediated defense mechanism against viruses is mostly confined to fungi, invertebrates, and plants. However, animal viruses are also discovered to be subject to the host RNAi-mediated suppression. Hence, within the evolutionary arms race between host and viruses, viruses have also evolved ways to nullify RNAi-mediated cellular anti-viral defense. Viral proteins underlying these mechanisms are referred to as RNAi suppressors. Aside from their roles in the viral life cycle in various ways, these proteins also manipulate histone and DNA methyltransferases as the components of the host’s transcriptional gene-silencing mechanisms to dampen the cellular antiviral silencing mechanism . Many maUtilizing exosomes as a drug delivery system was proposed in 2011 , and it Due to the regenerative functions of exosomes secreted from MSC, they are an ideal source of exosomes in a variety of diseases such as cardiac ischemia, liver fibrosis, and cerebrovascular diseases. The therapeutic effects of miRNAs delivered by MSC-derived exosomes have been demonstrated by a handful of studies as well , 143.In COVID-19, similar to other infectious diseases, the immune cells utilize miRNA-carrying exosomes to target the infected cells’ viral RNA. Thus, further delivery of specifically-designed ncRNAs by MSC-derived exosomes can accelerate the combat against SARS-CoV-2 and induce tissue regeneration . To asseTo combine the aforementioned anti-COVID-19 impact of MSC-derived exosomes with the iRNAs against SARS-CoV-2 pathogenesis, exosomes collected from MSCs should be loaded with the iRNAs of interest. MSCs of multiple sources can be used as exosome donors, including the umbilical cord, bone marrow, and adipose tissue . Mainly,When synthesized exogenously, siRNAs, miRNA mimics, and anti-miRNA oligonucleotides can be transferred into the exosomes via electroporation, lipofection, sonication, calcium chloride, co-incubation, or Saponin permeabilization , 147. MuAlternatively, it is established that increasing the concentration of iRNAs in the cytosol of the cell is concomitant with their heightened copy number in exosomes . In thisMultiple clinical trials are assessing the efficacy of MSCs and MSC-derived exosomes in alleviating COVID-19 manifestations in critically-ill patients. Enrichment of MSC-derived exosomes carrying exogenous iRNAs for COVID-19 therapy serves as an unprecedented strategy and is yet to be exploited in clinical settings. The right cocktail of iRNAs would not only impede viral propagation, inflammation induction, and immune escape in already-infected cells but also can obstruct the viral particles’ entrance to the un-infected cells and the virus’s further spread within the lung tissue.


Carbohydrate-coated nanoparticles—glyconanoparticles—are finding increased interest as tools in biomedicine. This compilation, mainly covering the past five years, comprises the use of gold, silver and ferrite (magnetic) nanoparticles, silicon-based and cadmium-based quantum dots. Applications in the detection of lectins/protein toxins, viruses and bacteria are covered, as well as advances in detection of cancer cells. The role of the carbohydrate moieties in stabilising nanoparticles and providing selectivity in bioassays is discussed, the issue of cytotoxicity encountered in some systems, especially semiconductor quantum dots, is also considered. Efforts to overcome the latter problem by using other types of nanoparticles, based on gold or silicon, are also presented. The use of nanoparticles (NPs) as biomedical tools has developed at pace in recent years, with NPs functionalised with carbohydrates (glyconanoparticles) emerging in diagnostics and cell imaging. Since the first report of glyconanoparticles , interesEscherichia coli-glyconanoparticle interactions, for instance  in the field of diagnostics . In the To date, glyconanoparticle-based detection assays have proven effective for lectin detection, including those associated with viruses and bacteria. The tuneable optical properties of gold NPs (AuNPs) and silver nanoparticles (AgNPs) make them ideal candidates for use in simple colorimetric assays . Given tvia Förster resonance energy transfer (FRET) was used as a switch on-off effect during the assay.The plant lectin Concanavalin A (ConA) has been widely used as a model to develop carbohydrate-based lectin detection systems. The specific interaction between glucosamine-functionalised AuNPs and ConA has been reported  to studyCdSe/ZnS QDs have been functionalised with quinolyl glucose (Glc) or quinolyl galactose  for the detection of ConA and peanut agglutinin (PNA), respectively . Both GlE. coli   and the E. coli , both baed AuNPs , showinged AuNPs . Here, tChromophores are often combined with either an enhancing or a supressing counterpart. A surface-enhanced Raman spectroscopy (SERS)-based assay for the detection of CTB was developed using silver nanoparticles presenting both PEGylated galactose and sialic acid (SA)  -capped ferrite nanoparticles were designed for the selective in vivo targeting of such receptors .A straightforward methodology for the preparation of AuNPs coated with α2,6-sialyllactose-containing polymer has been reported by Zhang et al.  and testSince the pandemic crisis caused by COVID-19 in early 2020, efforts have been made to detect SARS-CoV2 using glyconanoparticles. A lateral flow system for the rapid detection of coronavirus spike proteins was recently reported . Sialic Virus-glycan interactions have been shown to prevent virus internalisation in human cells through DC-SIGN/R receptors, which function as an entrance gate for viruses such as HIV or Ebola. AuNPs functionalised with the same high-mannose glycans present in the HIV glycoprotein gp120  togetherE. coli fimbrial adhesion FimH, mannose-coated CdS QDs have been used (E. coli K-12 strain (FimH+) and using the TOP10 strain (FimH-) as negative control. The stability of the nanoparticles in solution was improved by using a PEG-3000 tether, rather than directly binding the respective thiosugar to the AuNPs.The detection of bacterial pathogens represents an ongoing need in the field of health care. To target the een used . More reeen used  to detecE. coli based on the fluorescent properties of glycoacrylamides (Glc-bis) has been reported , galactose- or fucose-functionalised AuNPs have been used to target, detect and kill ruginosa . The fund linker . Successcoli (E. coli with the bacteria-specific glycoconjugate GM3 [Neu5Ac(α2-3)-Gal-β(1-4)Glc-βsp] “clicked” onto the surface of magnetite nanoparticles. Anti-bacterial effects were achieved via magnetically-mediated energy delivery (MagMED), where heat is generated in situ by the application of alternating magnetic fields , together with galactose-binding galectins, are cancer markers of increasing interest . GalectiGarcía Calavia et al. reported an anti-cancer photodynamic therapy system based on bi-functionalised AuNPs . The galHuman carcinoma cells have been targeted with silicon-based glyco-quantum dots . Work haMagnetic glyconanoparticles have been employed in combination with magnetic resonance imaging (MRI) to detect cancer cells, avoiding the need of labelling the cells beforehand . A collein vitro and in vivo imaging of tumours, together with detection and theranostic applications , efforts to produce more robust and less toxic nanomaterials is key to future in vivo applications. The field continues to progress at pace and impactful developments in the coming decade are anticipated.The range of applications of glyconanoparticles and the related carbohydrate-functionalised quantum dots is ever-expanding, with applications across detection for diagnosis of infectious diseases and cancer. For


Guidance errors and unrefined neural map configurations appear linked to certain neurodevelopmental conditions, including autism spectrum disorders. Deficits in specific multisensory tasks that require midbrain processing are highly predictive of cognitive and behavioral phenotypes associated with such syndromes. The lateral cortex of the inferior colliculus (LCIC) is a shell region of the mesencephalon that integrates converging information from multiple levels and modalities. Mature LCIC sensory maps are discretely-organized, mimicking its compartmental micro-organization. Intermittent modular domains receive patchy somatosensory connections, while inputs of auditory origin terminate in the encompassing extramodular matrix.Eph-ephrin signaling mechanisms instruct comparable topographic arrangements in a variety of other systems. Whether Eph-ephrin interactions also govern the assembly of LCIC multimodal maps remains unaddressed. Previously, we identified EphA4 and ephrin-B2 as key mediators, with overlapping expression patterns that align with emerging LCIC modules. Here, we implicate another member of this guidance family, ephrin-B3, and quantify its transient expression with respect to neurochemically-defined LCIC compartments. Multiple-labeling studies in GAD67-GFP knock-in mice reveal extramodular ephrin-B3 expression, complementary to that of EphA4 and ephrin-B2. This distinctive pattern sharpens over the early postnatal period (birth to P8), prior to ephrin-B3 downregulation once multimodal LCIC inputs are largely segregated (P12). Channel-specific sampling of LCIC ROIs show ephrin-B3 signal periodicities that are out-of-phase with glutamic acid decarboxylase  signal fluctuations, and match calretinin (CR) waveforms (matrix marker). Taken together, the guidance mosaic registry with emerging LCIC compartments and its interfacing afferent streams suggest a prominent role for Eph-ephrins in ordering behaviorally significant multisensory midbrain networks. In addition to passing on auditory space-mapped representations through topographic projections to the SC  as a reliable extramodular marker during an early critical period  and heterozygous GAD67-GFP transgenic mice (n = 38) over a defined critical period  for LCIC compartmentalization and developing afferent patterns . Specifics concerning the generation of the GAD67-GFP (Δ neo) line are described elsewhere .Experiments were performed in C57BL/6J  at room temperature for 40 min and agitated overnight at 4°C. For double-labeling studies, a directly conjugated secondary was used for CR visualization , paired with a biotinylated-streptavidin detection system for ephrin-B3 . Following final PBS rinses, sections were mounted in serial order on charged slides and coverslipped with ProLong Diamond anti-fade protection .A coronal series of midbrain sections at each of the designated ages was collected and processed similar to that previously reported in detail  fitted with a Hamamatsu ORCA-Flash 4.0 V3 sCMOS monochrome camera  was used for epifluorescence capturing of individual channels throughout the rostrocaudal extent of the LCIC. Filter sets  designed specifically to prevent bleed-through enabled unequivocal identification of the various fluorophores. Acquired Z-stacks for each channel were pseudocolored  and flattened using an extended depth of field (EDF) deconvolution algorithm .Individual channels for representative sections through aspects of the LCIC where its modular-extramodular organization is most evident were extracted separately as uncompressed TIFFS, opened in ImageJ , and converted to grayscale for pattern sampling and generation of brightness profile data sets for quantitative assessments. A freehand tool with a line thickness of 100  was used to sample LCIC layer 2, bisecting discontinuous GAD-positive modules. Sampling contours were drawn initially on imported GAD channels in a ventral-to-dorsal progression. The region of interest (ROI) manager was used in ImageJ to replicate the identical contour drawn in the GAD channel for each subsequent channel sampled. LCIC layer 2 sampling was similarly performed in P0 mice, although GAD-positive modules were not readily apparent at this earliest time point  was analyzed at each age and included in the statistical analyses. Age differences in this metric were tested using independent, two-tailed Student’s t-tests assuming unequal variance (Type 3) with statistical significance (p < 0.05).Signal processing was performed in keeping with previous protocols assessing continuous and discrete IC developmental patterns , but not P4 vs. P8 .In keeping with qualitative observations, ephrin-B3 expression patterns and GAD-positive modular domains become increasingly distinct from birth to P8, as shown by cross-correlation analyses . No crosOff-origin cross-correlation function peaks and troughs indicate matching and mismatching signal variations, respectively, occurring at particular relative spatial shifts between the two signals. At birth, y-intercepts  are close to zero, while non-zero signal shifts produce values that oscillate arbitrarily at brief intervals (every 25–50 μm) that do not reflect any anatomically significant features regarding the developing LCIC architecture . In contDouble-labeling experiments for ephrin-B3 and CR (an established extramodular marker) were performed in P8 GAD67-GFP mice to further confirm its matrix expression pattern. This age was chosen as it is the height of observed ephrin-B3 expression and pattern specificity, before its downregulation at P12. Both ephrin-B3 and CR are expressed throughout the LCIC extent that GAD-GFP modules span . ConsistA sampling of multiple labels at P8 reveals three periodic channel waveforms with combinatorial readouts that were either in- or out-of-phase with each other . GAD wavNuclear compartmentalization and guidance of specific inputs to emerging organizational features are critical steps in the establishment of highly integrative networks. The LCIC epitomizes such an orderly arrangement, with its modular-extramodular framework and converging inputs of multiple modalities  and axonal targeting (modular vs matrix-specific inputs). Previous reports from our lab identified EphA4 and ephrin-B2 as having discrete LCIC expression patterns that align with GAD-positive modular fields and are offset from the CR-positive matrix  whereby Eph-ephrin signaling instructs early multimodal LCIC projection specificity.Here, we show a similar temporal regulation for ephrin-B3 that exhibits a pattern complementary to that described previously for EphA4 and ephrin-B2 . Instead of discrete zones of labeling, Eph-ephrins are expressed in gradients along its tonotopic axis and are important for accurate targeting and refinement of frequency-specific inputs . Written informed consent was obtained from the owners for the participation of their animals in this study.JS and MG designed the experiments. JS executed all experimentation and associated imaging. CB and JC performed sampling for quantitative assessments. MG analyzed and interpreted the data, prepared all figures/tables, and wrote the article. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


CG-positive BCs were comprised of genetically diverse strain variants.The long-standing paradigm is that almost all BSIs stem from a single, clonal organism (“single-organism” hypothesis). We hypothesized that CG colonies were isolated from positive BC bottles from ten distinct patients (pts) for a total of 94 clones, which underwent NextGen short-read sequencing (Illumina). Variants were analyzed using SNPeff, and a phylogeny was constructed with Maximum Likelihood method.Five to ten CG strains that were unique to each pt [Fig. 1]. All strains were genetically distinct, differing by unique SNPs and insertions-deletions (indels) [Fig. 2-3]. SNPs were ~8-fold more common than indels. Individual genomes from the same time point in the same pt exhibited consistent magnitude of variations relative to reference genome; however, variations were unique, pointing to significant genomic variability that could be both intra- and interclonal. The number of variant sites for within-pt pairwise clone comparisons ranged from 1924-8500. There were 124,145 variant sites when all clones are compared. Roughly half of all SNPs were identical in different samples from a given pt; the remainder were present/absent in at least one sample per pt. Long-read WGS revealed strains with structural variants in each pt, including chromosomal recombinations and gene duplications that were not evident by short-read WGS. A genomic phylogeny construction showed that 94 clones spanned 3 distinct clades that were distinct from the reference strain. Finally, comparison of non-synonymous mutations among intra-pt clones showed overwhelming overrepresentation of adhesin and adhesin-like genes, pointing to possible importance in host adaptation. BCs harbored a diverse population of Venn diagram of core genome SNPs of 5 Candida glabrata recovered from blood cultures of patient C.C. glabrata in BCs of individuals with BSIs. We are studying phenotypic diversity of strain variants, and the clinical implications of genetically diverse Candida BSIs. Preliminary analyses revealed genetically diverse populations of Cornelius J. Clancy, MD, Merck (Grant/Research Support) Minh-Hong Nguyen, MD, Merck (Grant/Research Support)


Little evidence exists that validates 123 I-FP-CIT SPECT as a supplementary method to diagnose probable DLB in a psychiatric cohort of patients with psychiatric symptomatology and suspected DLB. We aim to elucidate differences in the clinical phenotype of DLB between those patients with and those without a positive 123 I-FP-CIT SPECT indicating a nigrostriatal deficit.To investigate this, we included 67 patients from the Department of Psychiatry and Psychotherapy at University Medical Center Göttingen (UMG) in our study who had undergone 123I-FP-CIT SPECT in the Department of Nuclear Medicine (UMG) by evaluating their patient files.p < 0.05). In addition, prodromal DLB and prodromal DLB patients with a psychiatric-phenotype yielded higher numbers post-123I-FP-CIT SPECT than pre-123I-FP-CIT SPECT (p < 0.05). Furthermore, we discovered no phenotypical differences between those DLB patients with a positive and those with a negative 123I-FP-CIT SPECT. 123I-FP-CIT SPECT-positive DLB patients in our psychiatric cohort revealed a psychiatric onset more often (52%); DLB was less often characterized by an MCI onset (26%) (p < 0.005).55% with a positive-123I-FP-CIT SPECT and probable DLB after the 123I-FP-CIT SPECT exhibited psychiatric features. The number of probable DLB patients in those exhibiting psychiatric symptoms was higher post-123I-FP-CIT SPECT than pre-123I-FP-CIT SPECT assessed cross-sectionally over a 6-year period (Our findings support 123I-FP-CIT SPECT as an adjuvant tool for improving the diagnosis of probable DLB and prodromal DLB in a cohort of psychiatric patients with often concomitant psychiatric symptomatology. The psychiatric-onset is more frequent than an MCI-onset in DLB patients presenting nigrostriatal dysfunction, giving us an indication of the relevance of deep clinical phenotyping in memory clinics that includes the assessment of psychopathology. Furthermore, we want to assess any differences in the neuropsychological and clinical phenotypes of patients with a positive 123I-FP-CIT SPECT vs. those with a negative 123I-FP-CIT SPECT.Dementia with Lewy bodies (DLB) is a frequent neurodegenerative dementia occurring in about 8% of all dementia patients . The proWe conducted a retrospective and observational study in 67 patients from a base cohort of 825 patients that received a 123I-FP-CIT SPECT in the Department of Nuclear Medicine of the UMG with suspected DLB who were examined in the Department of Psychiatry of the University Medical Center Göttingen (UMG). Probable and possible DLB patients were diagnosed in accordance with the McKeith criteria , as was via the ordered subset expectation maximization (OSEM) algorithm. OSEM consists of 5 iterations, 10 subcategories as well as a Butterworth filter. We employed Chang’s attenuation correction technique. Image analysis was done visually and semi-quantitatively using GE DaTQuant . 123I-FP-CIT-SPECT images were visually rated abnormal if: (1) tracer uptake was asymmetric between the hemispheres with a marked reduction in one of the putamen, (2) was reduced bilaterally within the putamen, or (3) was bilaterally absent. Furthermore, semi-quantitative analysis of striatal uptake was done with DaTQuant and the left and right striata-to-background ratios (SBRs) were calculated using a background region of interest over the occipital lobe representing cortical background. The lowest SBR between right and left striata was used for further analysis as described and applied in clinical practice . A 128 × 128 matrix at an energy setting of 159 keV ± 10%. Images were reconstructed practice . All druvia the patient history documented in patient files. The same was done for RBD patients who had not undergone polysomnography, but whose prior diagnosis or related facts in their patient history suggested RBD. We excluded patients from our cohort who exhibited any other reasons for cognitive or motor impairment such as Alzheimer’s disease, Parkinson’s disease dementia, Parkinson’s disease, or other neurodegenerative disorders such as multiple system atrophy or progressive supranuclear palsy. To differentiate PD from DLB, we relied on our time criterium of 12 months in addition to McKeith’s specific criteria . Neuropsychological testing was done to assess patients’ performance in cognitive domains via a detailed neuropsychological test battery including the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD)-Plus. Mild cognitive impairment (MCI) was defined as a neuropsychological performance below -1 to -2 fold of the standard deviation in one or more cognitive domains. The clinical features and supportive biomarkers were retrospectively evaluated by relying on electronic patient records. The following terms  were assessed applying a dichotomous score that indicates whether the symptom is present (score = 1) or not (score = 0): fluctuating cognition, REM sleep behavioral disorder, repetitive hallucinations, parkinsonism, neuroleptic hypersensitivity, postural instability, falls, transient episodes of unresponsiveness, syncopes, severe autonomic dysfunction, hypersomnia, hyposmia, parkinsonism, hallucinations in other modalities, delusions, apathy, anxiety, depression and supportive biomarkers [temporal preservation and electroencephalography (EEG) slowing]. Hyposmia was assessed criteria , 2020. Icriteria  and latecriteria . Our stut-tests were utilized to compare age groups (MCI-onset vs. mixed-onset) and the number of DLB patients  with possible or probable DLB before and after 123I-FP-CIT SPECT testing over a 6-year period. For not normally distributed group data , we compared the patients’ age via the Mann-Whitney U test. Fisher’s exact tests were used to compare the number of patients with DLB (psychiatric cohort and psychiatric features) and no LBD after two different classifications  for statistical analysis and SigmaPlot  for graph construction. Fisher’s exact test was utilized to compare the frequency of sex, psychiatric features in DLB, psychiatric-onset of DLB, MCI- onset of DLB, one or more core clinical DLB features, core and supportive clinical DLB features, and DLB biomarkers in patients between groups  with Bonferroni correction for multiple testing. In addition, the three groups were compared by Student’s ications , 2020 prn = 30, psychiatric-onset DLB), (2) MCI-onset  or (3) a mixed-onset . Of our patients with a psychiatric-onset and mixed -DLB onset, 18 suffered from late-onset depression and five from a late-onset schizophrenia-like psychosis. At the time of 123I-FP-CIT-SPECT, all patients presented cognitive dysfunction, and parkinsonism was also often present. We classified MCI- and psychiatric-onset DLB patients according to McKeith’s criteria for prodromal DLB ; and 14 patients underwent EEG .We enrolled 67 patients who had presented in the Department of Psychiatry and Psychotherapy in the UMG with suspected DLB during 2014–2020 and who had undergone 123I-FP-CIT SPECT in the Department of Nuclear Medicine in the UMG. All 67 patients with suspected DLB or probable DLB underwent 123-FP-CIT SPECT. The term suspected DLB entails the following categories: (1) possible DLB, or (2) prodromal DLB patients, or (3) patients with suspected DLB from their neuropsychological examination. Probable DLB patients underwent 123-FP-CIT SPECT with the aim of confirming a probable DLB diagnosis—that is, where we harbored doubts about the diagnosis, or about core clinical features derived from the patient history. Among our 67-patient cohort, we observed positive 123I-FP-CIT SPECT results from 58 patients and negative 123I-FP-CIT-SPECT results from nine patients. We formed three groups categorizing prodromal, possible and probable DLB from those 58 DLB patients presenting a positive nigrostriatal deficit in 123I-FP-CIT-SPECT imaging: (1) with a psychiatric-onset . Furthermore, 123I-FP-CIT SPECT increased significantly the number of patients with prodromal DLB after 123I-FP-CIT SPECT when compared to patients with no DLB, which on the contrary dropped after 123I-FP-CIT SPECT imaging (p < 0.05).If we consider the period between 2014 and 2020, 123I-FP-CIT SPECT does in fact raise the number of probable DLB and probable psychiatric DLB patients significantly (p < 0.005).DLB patients (possible and probable) with a psychiatric onset do exhibit a non-significant trend toward a psychiatric-phenotypic appearance more often at stages of full disease manifestation in conjunction with depressive, anxiety, and delusional symptoms than those with a MCI-onset . Other cWe identified no relevant differences between 123I-FP-CIT SPECT -positive and -negative groups in both their core clinical and supportive clinical features  and results from our visual analysis in the entire patient cohort. A two factorial ANOVA revealed no significant group differences in the groups’ SBRs , and that our patient cohort did not contain possible DLB patients exclusively, but rather some with probable DLB also—for whom, although 123I-FP-CIT SPECT can confirm DLB, it is not required to make the diagnosis. Furthermore, as we did not compare our results with a patient cohort from a neurology or movement-disorder clinic undergoing 123I-FP-CIT SPECT, we cannot claim that our results are specific to a psychiatric population. In addition, it is often difficult to know which symptoms patients exhibited when their disease started, in particular when psychiatric or cognitive symptoms coincide. Thus, if no clear differentiation was possible, we assumed a mixed-onset. In addition, the reader should keep in mind when interpreting our findings that DLB is more frequent in a given population if their 123I-FP-CIT SPECT is abnormal. Furthermore, as only some of our DLB patients underwent additional neuroimaging and electroencephalographic examinations, we have no access to other supplemental biomarkers in this retrospective study due to small sample sizes. As limiting factors we must mention due to our study’s retrospective design, that we did not test for anosmia or hyposmia disorder . As our In conclusion, 123I-FP-CIT SPECT is an important tool through which to detect decreased striatal dopamine transporter density in patients presenting suspected [appearing as single or multidomain non-amnestic MCI or multidomain amnestic MCI according to McKeith criteria ] or possData are available from the corresponding author.The studies involving human participants were reviewed and approved by the Ethics Committee of the Medical University Center of Göttingen. Written informed consent for participation was not required for this study in accordance with the national legislation and the institutional requirements.NH and CB wrote the manuscript. NH, CB, CT, and CL designed the study as well as collected and analyzed the data. CB, CL, CT, and JW discussed and revised the manuscript for important intellectual content. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.