Although among women a decreasing prevalence of human papillomavirus (HPV) infection with increasing age has been consistently observed in high-resource countries, different age profiles have been reported elsewhere.We compared the age profile of high-risk (HR)-HPV prevalence in nine different areas of Northern and Central Italy by studying the women recruited in the intervention arm of the New Technologies in Cervical Cancer study and tested by Hybrid Capture 2. Differences in the age-distribution of HPV infection were investigated in each centre by the joinpoint approach in a logistic model. 46,900 women aged 25 to 60 years were included in the analysis.The HR-HPV age-standardised  prevalence ranged from 5.7% (Trento) to 10.3% (Ravenna). HR-HPV prevalence decreased as a logistic function of increasing age in 6 of 9 centres . The effect of age on HR-HPV prevalence slopes did not differ significantly among these 6 centres, whereas significant heterogeneity in intercepts (p < 0.001) was found, reflecting different overall HR-HPV prevalence between centres. One significant joinpoint was observed in 2 centres (Padua and Ravenna), indicating that the decrease in HR-HPV prevalence by age was better described using a function composed with two logistic segments. In Padua HR-HPV prevalence decreased only slightly up to 39 years but showed a steep downturn thereafter. In Ravenna HR-HPV prevalence decreased steeply down to 45 years of age and then showed a plateau. Finally, in Turin two significant joinpoints were observed: prevalence decreased only after age 29 and showed a plateau after age 39.per se.Our results showed substantial differences in overall and age-specific HR-HPV prevalence across Italian areas. These findings may be related to different timing of changes in sexual behaviours across regions. Age-specific HR-HPV prevalence in Italy does not support an influence of age  The prevalence of cervical human papillomavirus (HPV) infection varies across populations and according to a woman’s age. Studies from Europe-4 and NoThe very steep increase in the cumulative incidence of HPV infection observed among women who had recently become sexually active suggested that a majority of women acquire the infection in the first few years after sexual debut,20. HowePrevious studies were, however, based on samples of a few hundreds or few thousands women overall, limiting the possibility of studying age effect in detail. Therefore, we aimed at assessing HR-HPV prevalence and possible variations in the age-distribution of HPV prevalence in 46,900 women from a large multicentre randomised controlled trial conducted across nine different areas in Italy.versus HPV testing) for which the main endpoint was histologic detection of cervical intraepithelial neoplasia of grade 2 or more. Our report is based only on the HPV testing arm of NTCC. NTCC was conducted within organised cervical cancer screening programmes in nine centres in Northern and Central Italy  and was considered in determining HPV prevalence. Figure The New Technologies in Cervical Cancer (NTCC) study is a randomized trial of screening methods  or in the standard transport medium (Qiagen Incorporated) (NTCC phase 2). The Hybrid Capture 2 (HC2) hybridization assay  targeting HR-HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68, was used to determine HR-HPV presence with a cut point of 1 relative light unit (RLU) for HPV positivity, as recommended by the manufacturer. High reproducibility of HPV testing between laboratories was documented.HR-HPV status from the first valid HC2 test was considered. For each centre, HR-HPV prevalence was standardized to the 2004 Italian female population in the same age groups for year 2004 aged 25–60 years. The hetThe age-distribution of HR-HPV prevalence in each recruitment centre was assessed performing a logistic joinpoint regression analysis. This method allows characterizing the age-specific prevalence using joint linear segments with different slopes, where the joinpoints represent the points of change in slope. If no significant joinpoints were identified, we characterized the age-specific HR-HPV prevalence profiles using a standard logistic regression with studied differences between centres and logistic effect of age as suggested by the intercepts and the slopes. For the centres without any significant joinpoint we tested the significance (significance level < 0.05) of differences between centres in intercepts, reflecting different overall HR-HPV prevalence, and age slopes, reflecting different declines of HR-HPV prevalence as a function of age. To test for significant differences in intercepts between centres we performed a log-likelihood ratio test comparing two logistic regression models: one accounting only for age as independent variable, the other for both age and centres. Similarly, to test for different declines of HR-HPV prevalence as a function of age among centres, we tested the statistical significance of the interaction between centres and age performing a log-likelihood ratio test.j joinpoint(s) versus the alternative of j + 1 joinpoint(s). The p-value is determined by a Monte Carlo method[jmax = 3) and set as significance level < 0.05). All the other statistical analyses were performed using STATA software .To test for the presence of statistically significant (significance level < 0.05) joinpoints and to estimate their value, we used the package “ljr” from the CRAN repository. In parto method. We alloA total of 47,369 women were randomly assigned to the HPV testing arm. After the exclusion of 469 women who did not have any valid HPV test, 46,900 women could be included in the present analysis.Table No significant joinpoints were observed in six of the nine centres . HR-HPV prevalence in these centres decreased as a logistic function of increasing age. Significant heterogeneity in intercepts (p < 0.001), as assessed performing a log-likelihood ratio test, was found between centres, reflecting different overall HR-HPV prevalence Figure . While HFigure We observed geographical variation in age-standardized and age-specific prevalence of HR- HPV infection in the Italian centres participating in the NTCC study; with the highest age-standardized prevalence in Ravenna (close to a touristic sea resort area) almost twice that of Trento , the lowest prevalence. Given that relevant differences in biological features of HR-HPV infections across Italian regions are implausible, the observed geographical variations are likely to reflect differences in sexual behaviour across Italian areas.In addition, although in all study centres HR-HPV prevalence followed the general pattern of decrease with increasing age typical of industrialised countries, qualitative differences were found  in the shape of age specific prevalence. In the majority of NTCC centres HR-HPV prevalence decreased as a logistic function of increasing age, i.e., a logistic function described HR-HPV prevalence reduction within the considered 25-to-60-year-old age range. In Turin and Padua, however, women showed higher HR-HPV infection prevalence up to about age 30 and 40 years, respectively. The same age-distribution of HR-HPV prevalence in Turin had been found in a previous smaller study. In turnOf notice, a steeper decrease in HR-HPV prevalence with age than that found in the NTCC study was observed in a study conducted in Central and Southern Italy. This fiDifferences in sexual habits and birth cohort effects may herald different future changes in the incidence of precancerous and cancerous lesions of the cervix in different parts of Italy. Increases in both incidence of and mThe variation in the shape of age-specific HR-HPV prevalence observed between centres in the NTCC study could also derive from different population mixing. On account of important migratory waves, for instance, less than half of the population living in Turin in 2011 was born in the city. As for many other large towns across industrialized countries, Turin is constantly subject to rural-to-urban migrations. Main reasons for immigration from both other Italian areas and abroad are studying and working purposes. We speculate that the constant inflow of relatively young immigrants may have an impact on sexual promiscuity and transmission chain of HPV infections. The consequences of immigration on older birth-cohorts are of less straightforward interpretation. Demographically relevant migrations to Turin, initially from Southern and North-eastern Italy, started in the 1960s. Almost half the women migrated to Turin from Southern Italy arrived during such period and would have not fallen in the age range eligible for the NTCC study.Our study has strengths and weaknesses. Study population is large and can be considered well representative of women aged between 25 and 60 years who participate in screening in the study areas. In a previous study of the determinants of screening attendance in Turin, we founper se in HR-HPV prevalence.In conclusion, we observed substantial differences in overall and age-specific HPV prevalence across Italian areas. These findings may be related to differences in sexual behaviour of women in different age groups and birth cohorts and in population mixing across study areas. Awareness of the existence of age or cohort effects may be useful in predicting trends in precancerous and cancerous lesions of the cervix and modelling the future impact of screening or HR-HPV vaccination in different Italian areas. In any case, the heterogeneity we observed does not support an influence of age CI: Confidence interval; CIN: Cervical intraepithelial neoplasia; HR: High-risk; HPV: Human papillomavirus; HC2: Hybrid capture 2; NTCC: New technologies in cervical cancer; RLU: Relative light unit.The authors declare that they have no competing interests.SF, GR, IB conceived the study. GR, SF, PGR and NS were involved in the study design. AGT, FC, MC, PDP, MDL, ADM, LDM and CN collected data. PP, PS, NS, MZ and PGR were responsible for quality control of data and algorithms. IB, GR performed statistical analysis and data analysis and interpretation with SF. IB, GR and SF drafted the manuscript and NS, FC and PGR edited it. All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2334/13/238/prepubSupplementary information.Click here for file


Nuclear medicine imaging techniques offer whole body imaging for localization of number and site of infective foci inspite of limitation of spatial resolution. The innate human immune system contains a large member of important elements including antimicrobial peptides to combat any form of infection. However, development of antibiotics against bacteria progressed rapidly and gained popularity over antimicrobial peptides but even powerful antimicrobials failed to reduce morbidity and mortality due to emergence of mutant strains of bacteria resulting in antimicrobial resistance. Differentiation between infection and inflammation using radiolabeled compounds with nuclear medicine techniques has always been a dilemma which is still to be resolved. Starting from nonspecific tracers to specific radiolabeled tracers, the question is still unanswered. Specific radiolabeled tracers included antibiotics and antimicrobial peptides which bind directly to the bacteria for efficient localization with advanced nuclear medicine equipments. However, there are merits and demerits attributed to each. In the current paper, radiolabeled antibiotics and radiolabeled peptides for infection localization have been discussed starting with the background of primitive nonspecific tracers. Radiolabeled antimicrobial peptides have certain merits compared with labeled antibiotics which make them superior agents for localization of infective focus. The defensins peptides, calprotectin protein, and ubiquicidin cationic peptides are found in macrophages [α-grounds contain certain cationic antimicrobial peptides having broad spectrum antimicrobial activity [Blood-derived antimicrobial proteins and peptides being part of innate immunity target the microbial membranes leading to growth arrest and, in some instants, neutralization of proinflammatory surface components like lipopolysaccharides. Different inflammatory response blood cells like neutrophils, eosinophils, macrophages, and platelets contain antimicrobial proteins and peptides which have affinity for surface lipids of microbial as opposed to eukaryotic cells. Neutrophils contain primary and secondary granules in their cytoplasm which contain antimicrobial proteins and peptides. Lactoferrin is localized in the secondary granules, which has direct microbicidal effect, presumably via membrane disruption. Activated neutrophils release bactericidal/permeability increasing protein (BPI) into inflammatory fluids where it is potentially bactericidal. Serprocidins are proteases with cytotoxic activity localized in neutrophil primary granules. Cathelicidins are also antimicrobial peptides within secondary granules of neutrophils. The defensins are a family of 4-Kd peptides with broad cytotoxic activity against bacteria, fungi, parasites, viruses, and host cells. Humans express rophages . Plateleactivity . Multiplex vivo or by directly targeting leukocyte antigens or receptors in vivo via administration of radiolabelled antigranulocyte monoclonal antibodies on receptor-binding ligands [Differentiation between infection and inflammation is usually difficult. Clinicians use a variety of clues, for example, clinical, laboratory, and radiological tests, to aid in diagnosis and influence decision making. Commonly employed and useful modalities for demonstration of any focal lesion include conventional radiological techniques such as X-ray, ultrasound, computerized tomography (CT), magnetic resonance imaging (MRI), which demonstrate structural abnormalities which take some time to become visible, may not always be present, and their resolution lag behind cure. In addition they are neither inflammation nor infection specific. Nuclear medicine has enhanced infection imaging because it depends on the demonstration of pathophysiological and pathological changes, which occur earlier in infection process and also resolve quicker after cure of the infection compared with gross changes in structure . Scintig ligands . Howeverin vitro  111In-oxinate- or 99mTc-HMPAO-labeled leukocytes are still the gold standard for imaging infections [99mTc-HMPAO-labeled leukocytes in patients with suspected osteomyelitis [67Ga- and 111In-labeled leukocytes [18F-FDG-labeled autologous leukocytes has further improved the diagnosis and localization of infection lesions [99mTc-ciprofloxacin, which is an analog of a broad-spectrum quinolone antibiotic having the property of binding to DNA gyrase of bacteria and inhibiting DNA synthesis [99mTc agent showed encouraging results in various infections [Scintigraphy has the advantage of early elucidation of pathophysiological changes in the infective process; however, it is limited by poor resolution. Recent advances in nuclear medicine technology resulted in commercially available instrumentation such as single-photon emission computed tomography (SPECT) and positron emission tomography (PET) that have markedly improved anatomical details. Autologous fections –7. Planafections , 9, but myelitis . Marked  lesions ; however lesions . An earlynthesis . This 99fections –16; howefections . Due to fections .in vitro. Bacterial infections with Staphylococcus aureus and Klebsiella pneumoniae have been visualized in mice by 99mTc-labeled human neutrophil peptide-1 [99mTc, which targeted bacterial cells but not sterile inflammatory processes in experimental animals [Staphylococcus aureus infections in mice and Klebsiella pneumoniae in rabbits. As controls, inflammation was produced by lipopolysaccharides (LPSs) and heat-killed microorganisms [99mTc-labeled ubiquicidin (29–41) showed encouraging results for differentiation between infection and inflammation model. 99mTc-UBI (29–41) scintigraphy showed more accumulation of tracer in Staphylococcus-aureus-induced infection compared with that of Escherichia coli infection model. Optimum time for imaging was 60 min after tracer injection [99mTc-UBI can be utilized for monitoring efficacy and direction of antibiotic treatment [Antimicrobial peptides, produced by phagocytes, epithelial cells, endothelial cells, and many other cell types, are an important component of innate immunity against infection by a variety of pathogens . These peptide-1 . The baseptide-1 . Later,  animals . In laterganisms . Interacrganisms  and possrganisms . Multiplnjection . In anotreatment . Use of Phase-I clinical trial with this novel radiolabelled peptide showed overall sensitivity, specificity, and accuracy of 100%, 80%, and 94.4%, respectively, in patients with soft tissue infections and osteomyelitis. However, optimum time for imaging was 30 min after intravenous administration of radiotracer . 67Ga is a cyclotron-produced radionuclide, with a half-life of 78 hours, emits a broad spectrum of gamma rays between 93 keV and 880 keV. The energy peaks that are most suitable for gamma camera imaging are 93 keV, 184 keV, 296 keV, and 388 keV [67Ga binds to transferrin. This complex extravasates at the site of inflammation due to the locally enhanced vascular permeability, and in the inflammatory lesion it may transchelate to lactoferrin as present in leukocytes. The B-lymphocytes have lactoferrin-binding sites on their surface, which have high affinity for gallium. Additionally, macrophages engulf protein iron complexes and cellular debris, thereby accumulating gallium. Bacteria and fungi contain siderophores which are released for the purpose of scavenging iron and consequently bind gallium as a gallium-siderophore complex [ The oldest radiopharmaceutical proposed for imaging inflammation is Gallium-67 citrate which has been used for infection and inflammation ever since its discovery in 1971 . 67Ga is 388 keV . After i complex . The age complex , 34. Phy complex .67Ga-citrate scintigraphy has high sensitivity for both acute and chronic infection and noninfectious inflammation, there are several shortcomings that limit its clinical application. The specificity of the technique is low, due to physiological bowel excretion and accumulation in malignant tissues and areas of bone remodeling. In addition, the radiopharmaceutical has unfavorable imaging characteristics , causing high radiation-absorbed doses. Furthermore, optimal imaging often requires delayed recordings up to 72 hours. These unfavorable characteristics, in combination with the development of newer radiopharmaceuticals, have narrowed the clinical indication for gallium scintigraphy to certain conditions such as lung infections and chronic osteomyelitis. The sensitivity and specificity for chronic osteomyelitis are lower than for acute osteomyelitis [67Ga improves diagnostic efficiency as compared with planar or SPECT scanning [Although myelitis , 37. Usescanning . Galliumscanning .Υ receptors as expressed on infiltrating leucocytes [111In-oxinate as well as with 99mTc. Both agents have slow blood clearance and physiological uptake in the liver, the spleen, and the kidneys. The 99mTc-labeled preparation has the known ideal radiation characteristics, while the 111In-labeled preparation allows imaging at time points beyond 24 hours after injection. 111In-oxinate or 99mTc-labeled HIG has been extensively tested in a large number of clinical studies. It has shown excellent performance in the localization of musculoskeletal infection and inflammation [ Initially it was hypothesized that human polyclonal immunoglobulin (HIG) was retained in infectious foci owing to the interaction with Fc-ucocytes . Later sucocytes . For cliammation . In addiammation  and abdoammation , 44.111In-oxinate and with 99mTc, either using hexamethylpropylene amine oxime (HMPAO) as an internal label or via HYNIC as an external chelator. Labeling is easy and takes only minutes [99mTc-PEG-liposomes were directly compared with 111In-IgG scintigraphy. 99mTc-PEG-liposome scintigraphy has shown high sensitivity (94%) and specificity (89%) [ Liposomes are spheres consisting of one or more lipid bilayers surrounding an aqueous space. They were proposed as vehicles to image infection some 20 years ago, but the preparations used in those early years were cleared from the circulation very rapidly by the mononuclear phagocyte system (MPS). However, if the surface of the liposomes is coated with a hydrophilic polymer such as polyethylene glycol (PEG), they circumvent recognition by the MPS, leading to a prolonged residence time in the circulation and enhanced uptake at pathological sites by extravasation due to locally enhanced vascular permeability . Such st minutes . The firty (89%) .  Avidins are a family of proteins present in the eggs of amphibians, reptiles, and birds; streptavidin is a member of the same family. Avidin and streptavidin  bind to biotin with extremely high affinity. Biotin is a compound of low molecular weight that can be radiolabelled. The avidin-biotin approach is based on the fact that avidin (or streptavidin) will nonspecifically localize at sites of infection owing to increased vascular permeability. Avidin (or streptavidin) is injected as a pretargeting agent, followed hours later by a second injection with radiolabelled biotin. Good diagnostic accuracy was demonstrated in studies of vascular infection and chronic osteomyelitis –51. Ex vivo labeled autologous leucocytes were developed in the 1970s and 1980s and their use is still considered the “gold standard” nuclear medicine technique for infection and inflammation imaging [in vitro leukocyte-labeling techniques have been used, the most commonly used procedure makes use of the lipophilic compounds 111In-Oxyquinoline and 99mTc-HMPAO. The radiolabeling procedure takes about 2-3 hours. Because all the cellular components of the blood can be labeled, it is necessary to separate the leukocytes from the erythrocytes and platelets. After withdrawal, therefore, the syringe containing the blood is kept in the upright position for about 1-2 hour to promote erythrocyte sedimentation. After the erythrocytes have been separated, the leukocytes must be separated from platelets. The leukocyte-rich plasma is centrifuged, and the leukocyte pellet that forms at the bottom of the tube is removed, incubated with the radiolabel, washed, and reinjected into the patient. The usual dose of 111In-labeled leukocytes is 10–18.5 MBq (300–500 μCi); the usual dose of 99mTc-HMPAO-labeled leukocytes is 185–370 MBq (5–10 mCi). Uptake of labeled leukocytes is dependent on intact chemotoxis, the number and types of cells labeled, and the cellular component of a particular inflammatory response. A total white cell count of at least 2000/mm3 is needed to obtain satisfactory images. Neutrophils can be radiolabeled and hence the procedure is most useful for identifying neutrophil-mediated inflammatory processes, such as bacterial infections. The procedure is less useful for those illnesses in which the predominant cellular response is other than neutrophilic, such as tuberculosis [ imaging –7. Althorculosis .111In-oxine-labeled leukocytes have been used to image infection and inflammation. The scintigraphic images reflect the distribution of white blood cells in the body. Since an abscess or other localized infection consists primarily of leukocytes, the radiopharmaceutical localizes at the site of infection [111In-labeled leukocytes, the normal distribution of activity is limited to the liver, spleen, and bone marrow. Large field of view gamma camera equipped with medium energy parallel hole collimator is used with 15% window centered on 174-Kev photopeak and 20% window centered on the 247-Kev photopeak. Advantages of the 111In label are a very stable label and constant normal distribution of activity limited to liver, spleen, and bone marrow. The 67-hour half-life of isotope allows delayed imaging, which is particularly valuable in musculoskeletal infection. Another advantage is conduction of bone or bone marrow scan immediately after completion of 111In-labeled study which is a limitation with 99mTc-labeled tracers [111In label include a low photon flux, less than ideal photon energies, and the fact that a 24-hour interval between injection and imaging is generally required. Causes of false-negative and false-positive 111In-leukocyte study are summarized in 111In-labeled white blood cells are laborious and time-consuming preparation, requiring specialized equipment and can be hazardous. Almost 3 hours are required for isolating and labeling a patient's white blood cells by a trained technician. In addition, the need to handle potentially contaminated blood can lead to transmission of blood-borne pathogens such as HIV and HBV. As anatomical land marks are not properly outlined with scintigraphy, the same is the limitation with 111In-WBC planar images. However, SPECT/CT with 111In-WBC scintigraphy markedly improves accurate identification of infection sites [For over two decades, nfection –61. Aftenfection , 63. At 99mTc-HMPAO-labeled leukocytes is more variable. In addition to the reticuloendothelial system, activity is also normally present in the genitourinary tract, large bowel, blood pool, and occasionally the gall bladder [99mTc-HMPAO has theoretical advantages over 111In-labeled leukocytes. 99mTc, being generator produced on site, could be immediately available for radiolabeling. The radiation dose to the patient would be significantly lower, permitting a higher administered activity. The higher photon yield of 99mTc would result in superior image resolution and improved infection detectability and accuracy.The normal bio-distribution of  bladder . The int111In-oxine-labeled leukocytes, 99mTc-HMPAO-labeled leukocytes are cleared by the hepatobiliary and renal systems [99mTc are disadvantages when 24-hour imaging is needed. This occurs in those infections that tend to be indolent and for which several hours may be necessary for accumulation of a sufficient quantity of labeled leukocytes to be successfully imaged. Bone or bone marrow scan if indicated after 99mTc-HMPAO-WBC scan has to be delayed at least for 48 hours and preferably 72 hours. For better anatomical localization of infection site, SPECT/CT with 99mTc-HMPAO-WBC scintigraphy is far better than planar/SPECT imaging with other infecting imaging agents [ HMPAO preferentially labels granulocytes, a potential advantage for imaging acute purulent processes. Unlike  systems –70. Disag agents .99mTc or 123I allowed accurate delineation of infection [ Several monoclonal antibodies reactive with antigens expressed on granulocytes  have been developed. At least three antigranulocyte antibodies have been tested for infection imaging: anti-NCA-95 IgG (BW250/183) , 72, antnfection . The antnfection .99mTc-labeled antigranulocyte Fab' fragment (LeukoScan) has been registered in Europe as an infection imaging agent.The use of antibody fragments instead of the whole antibody seems to be more advantageous, since such fragments appear to be less immunogenic. In addition, antibody fragments show faster blood clearance and may thus provide earlier diagnosis.  A wide variety of peptides that bind to receptors expressed on white blood cells have been tested for the detection of infection. One of the first receptor binding peptide tested for its ability to image infectious foci was chemotactic peptide formyl-Met-Leu-Phe. This tripeptide, which is N-terminally formylated, is a chemotactic factor produced by bacteria which binds to receptors on granulocytes and monocytes with high affinity –80. A dr The attraction of leukocytes to tissues is essential for inflammation and host response to infection. The process is controlled by chemokines, which are chemotactic cytokines. Over 40 chemokines have been identified to date, most of them in the past few years. Chemokines induce cell migration and activation by binding to specific G-protein-coupled cell surface receptors on target cells. Their receptors are expressed on different types of leukocytes. Some are restricted to certain cells, whereas others are more widely expressed . LabeledStaphylococcus aureus infections showed specific uptake of radioiodinated IL-1 at the site of infection [ Interleukin-1 (IL-1) binds receptors expressed mainly on granulocytes, monocytes, and lymphocytes, with high affinity. Studies in mice with focal nfection . Fever, nfection .123I or 99mTc-labeled IL-2 at the site of lymphocytic infiltration [ The IL-2 is considered to bind specifically to IL-2 receptors expressed on activated T lymphocytes. In a study in an animal model of human autoimmune diabetes mellitus, Hashimoto's thyroiditis, Grave's disease, Crohn's disease, Coeliac disease and other autoimmune diseases, demonstrated localization of ltration , 86.Escherichia coli infection, accumulation of 123I-labeled IL-8 in the abscess was rapid and high. The specific activity of this IL-8 preparation was relatively low, resulting in a transient reduction in peripheral leukocyte counts to 45% after a dose of 25 μg/kg 123I-IL-8, followed by leukocytosis for several hours. Recently, a 99mTc-labelled IL-8 preparation was developed using HYNIC as a chelator. In rabbits with Escherichia coli infection, high abscess uptake of 99mTc-HYNIC-IL-8 and high abscess-to-background ratios were obtained compared with those obtained using the radioiodinated preparation [ IL-8 binds to receptors on neutrophils with high affinity. In rabbits with focal paration –91.99mTc-P483H clearly delineated the infectious foci as early as 4 hours after injection. No systemic side effects were observed. 99mTc-P483H has been studied in patients to test its applicability as an imaging agent for scintigraphic detection of infection and inflammation, with fair results  [ Platelet factor 4 (PF-4), like IL-8, is a member of the CXC chemokines. PF-4 binds the CXC type II (= IL-8 type B) receptors expressed on neutrophils and monocytes. In a rabbit model of infection, ificity) , 93.18F-2-FDG-6 phosphate but is not metabolized. The degree of cellular FDG uptake is related to the cellular metabolic rate and the number of glucose transporters [FDG is transported into cells by glucose transporters and is phosphorylated by hexokinase enzyme to sporters –96. Actisporters . Althougsporters . Thymic sporters . Hepaticsporters .18FDG is now widely used. FDG is taken up by inflammatory cells with increased metabolic requirements. In contrast to glucose, deoxyglucose cannot leave the cell once it is taken up, so it can be used to image scintigraphically cells with high glucose uptake such as tumor cells and inflammatory cells. FDG-PET has been studied in a wide variety of infections, including lesions of bacterial, tuberculous, fungal, soft tissue, and bone infections [18F-FDG accumulation. The hybrid PET/CT technology improved diagnostic accuracy with precise registration of metabolic and structural imaging data. 18F-FDG PET/CT utilized for workup of osteomyelitis in diabetic foot correctly identified 93% of all infected sites [18F-FDG-WBC is a nonspecific tracer of increased glucose metabolism and does not accumulate only in sites of infection and inflammation but also shows false-positive results in tumor and postoperative changes [18F-FDG-labeled autologous leukocytes PET/CT for infection detection has demonstrated sensitivity, specificity, and accuracy of 91%, 85%, and 90%, respectively. Negative predictive value of 100% with this technique is a hallmark. 18F-FDG-WBC imaging is superior to 18F-FDG alone for infection detection as well as for assessment of response of infection to antibiotic treatment; however limited availability and cost are the limitations [Positron emission tomography (PET) with fections , 102. Sefections . FDG-PETfections –107. Forfections . High spfections . PET is ed sites . However changes . 18F-FDGitations . 99mTc-ciprofloxacin having many of the properties of an ideal infection-specific agent [The first antibiotic developed as a radiopharmaceutical was ic agent . Ciproflic agent , 113. ItIn vitro, ciprofloxacin is taken up by a wide variety of Gram-positive, Gram-negative, and anaerobic bacteria  but not by dead bacteria or white cells [99mTc-ciprofloxacin show rapid, predominantly urinary excretion of the tracer, with low-to-absent brain, lung, and bone marrow uptake and low liver uptake and excretion. Highest radiation dose was received by urinary bladder. Imaging conditions were excellent for both thoracic and abdominal regions, even at early time (60 minutes) after injection [ex vivo labeling, which avoids contact with blood and hence the risk of acquiring blood-borne infections such as H1V and hepatitis B and C, (5) independence of the host inflammatory response and neutrophil count and hence it can be used to image infections in immunocompromised patients, including those who are neutropaenic, where culture is often negative and white cell imaging unreliable, and (6) availability in a kit format with long shelf-life, making it user friendly and more widely available [99mTc-ciprofloxacin in sterile inflammation questioning its specificity [te cells , 115. Binjection . In a conjection . High spnjection . It alsonjection . No advevailable . Certaincificity –19.invitro animal model in which 99mTc-labeled antibiotic accumulated in infective sites of live Staphylococcus aureus bacteria and revealed no uptake in control models with heat-killed bacteria [Sparfloxacin is fluoroquinolon, antibiotic effective against a wide range of Gram-positive bacteria. It was successfully labeled and evaluated in bacteria .99mTc, in vitro studies did not show encouraging results in differentiating infection from inflammatory foci [This is also quinolone antibiotic used mainly in veterinary practice. Labeled with ory foci . Staphylococcus aureus, Streptococci, and Enterobacteriaceae. This drug is widely used at surgical and medical floors as prophylactic and treatment antibiotic. As per hypothesis, if such drugs are effectively labeled with radiotracer without altering the efficacy and effective binding with bacteria, localization of infective foci and monitoring the efficacy and duration of antibiotic treatment would be a big hallmark. This drug was effectively labeled with 99mTc and used to localize bone infections as the penetration of this antibiotic in bone is far better as compared with other antibiotics [Ceftizoxime is a 3rd-generation cephalosporin effective against a wide range of Gram-positive bacteria especially ibiotics .Mycobacterium tuberculosis infection in mice and rabbits. 99mTc-ethambutol accumulated at the site of infection as early as 2 hours after injection, which increased at 4 hours and persisted till 24 hours. Further studies with this agent are eagerly awaited [Ethambutol is a narrow-spectrum antibiotic, which is active against mycobacteria  and is used as a first-line drug for the treatment of tuberculosis (TB). Hence radiolabeled ethambutol is an attractive candidate for specifically imaging mycobacterial infections, including early TB. Good results were obtained in a thigh model of  awaited .99mTc followed by studies on mice and rabbits for labeling efficiency, in vitro and in vivo stability, blood kinetics, and organ distribution. Thigh model of localized tubercular lesion was prepared in rabbits after injecting 500 μL of 3 × 108 cells/mL of Mycobacterium tuberculosis live bacteria in growing phase . The localization of radiolabeled complex was studied with 70–75 MBq of 99mTc-INH intravenously with successful imaging at 2, 4, and 24 hours after tracer injection with increase in target to nontarget (T/NT) ratio gradually up to 24 hours. Labeling efficiency of the kit was >95% and only 2–3.5% of tracer leaked out from the complex or 24 hours when incubated in serum as 37°C, confirming its stability. Organ distribution studies showed renal source of excretion with no gastric or thyroid uptake suggesting good in vitro labeling efficiency and stability. As controls, infection was induced in rabbits with live Staphylococcus aureus after injection of 107 live bacteria followed by injection of same dose of 99mTc-INH and imaging under same parameters. Tracer accumulation was visualized in the infective foci from 2 hours after injection; however, delayed imaging revealed gradual clearance at 4 and 24 hours, which was in contradiction to findings with tuberculous lesions. Overall more than 95% sensitivity and high specificity were observed in the animal study. Therefore it was concluded that this radiolabeled agent can be used for detection and followup of tuberculous lesions in patients especially to determine the treatment endpoint of antituberculous drugs [99mTc and study in humans was tried in our set up but we were unable to localize lesions of tuberculous lymphadenitis in humans with this radiotracer.  Isoniazid (INH) is a specific antituberculous drug showing selective uptake in live mycobacteria based on its specific interaction with mycolic acid which is an important constituent of bacterial cell wall. This drug was successfully labeled with us drugs . SimilarCandida albicans and Aspergillus Fumigatus. Fluconazole is antifungal drug which was successfully labeled with 99mTc. This labeled compound successfully detected infections with Candida albicans but not bacterial infections or sterile inflammatory sites in animals. There was good correlation between 99mTc-Fluconazole accumulation and the number of viable Candida albicans which could be used as parameter for monitoring antifungal therapy. This agent is mainly excreted via the kidneys with little accumulation in the liver. However, it is not suited to detect Aspergillus fumigatus infections. However, this radiotracer is able to distinguish between Candida albicans infections from bacterial infections and sterile inflammations [Anticancer therapy, transplantation and AIDS give rise to infections with fungi such as mmations .+2 and Zn+2 concentrations) or to interactions with host cells, leading to enhanced antibacterial activities of the cells [ Peptides are composed of relatively small components, the amino acids. A difference between peptides and proteins is their size. Peptides are compounds with up to about 50 amino acids and a molecular mass below about 10,000 Dalton. In contrast, they generally do not possess a well-defined three-dimensional (tertiary) structure. Because of the lack of tertiary structure, small peptides are less susceptible to a loss of integrity through labeling conditions and are less immunogenic than proteins , 126. Anhe cells –129.Antimicrobial peptides usually contain <50 amino acids with a net positive charge created by an excess of basic residues, such as lysine and arginine, and ~50% hydrophobic amino acids.Antimicrobial peptides are essential components of the innate host defense because of their ability to kill a wide range of pathogens.They have a wide distribution throughout the animal and plant kingdoms.They are effectors of local and systemic immune responses. The latter is essentially found in insects.Although they share basic features such as small size, hydrophobicity, and cationic character, antimicrobial peptides have a great structural diversity.The majority of antimicrobial peptides are derived from larger precursors that harbor a signal sequence, whereas other peptides are generated by proteolysis from larger proteins (such as lactoferrin).In addition, some antimicrobial peptides such as mammalian defensins have other activities contributing to host defenses by mediating an acute inflammatory reaction and linking the innate with the acquired immune response .Difficulties arising in purifying natural antimicrobial peptides from various sources have prompted the recombinant production of antimicrobial peptides by genetically engineered bacteria or by peptide synthesis. Such methods result in sufficient amounts of antimicrobial peptides produced under good laboratory practice conditions, which is essential for use in animal and human studies. Synthetic peptides are usually small, rapidly removed from the circulation and other body compartments, and flexible, because they do not hold a particular structure in a hydrophilic environment, and display a favorable adverse effect profile.99mTc including indirect labeling using the preformed chelate approach or bifunctional chelating agents and the direct labeling method have been discussed extensively [99mTc-peptide in diluted human serum), and safe (no adverse effects in mice and rabbits). Unfortunately, the reaction mechanism underlying this 99mTc-labeling of peptides has not been elucidated. It may, however, involve the reduction of 99mTc, the production of a 99mTc intermediate, and the substitution reaction transferring the reduced 99mTc from this intermediate to the peptide [ The aim of radiolabeling techniques is to firmly attach or incorporate the radionuclide into the peptide without altering its biological functions, thus allowing a reliable evaluation of its pharmacokinetics after intravenous administration. The various methods of labeling peptides with ensively . The dir peptide .In vitro binding studies were used to select peptides displaying a preferential binding to microorganisms over human cells from a range of 99mTc-labeled human antimicrobial peptides/proteins and synthetic peptides derived from these natural peptides/proteins  domains of the peptides with the (negatively charged) surface of microorganisms . Given t One of the best-studied antimicrobial peptides is human neutrophil peptide-1 (HNP-1), which is a member of the family defensins. Initially, the potential use of HNP-1 for antibacterial therapy of experimental infections in mice was studied. The antibacterial effect was found to be associated with an increased influx of neutrophils into the infected area . Use of Immunocompromised mice produced by an injection of cyclophosphamide were utilized for detection of infection site induced by microorganisms which confirmed that accumulation of tracer was due to microorganisms, not due to inflammatory cells . In immu99mTc selectively localized the infection sites of bacteria and fungi through binding with their cell membranes and revealed minimum or no uptake in inflammatory model induced by LPS or heat-killed microorganisms [99mTc-antimicrobial peptide UBI (29–41) was appreciated in inflammatory models in rabbits induced with formalin-killed Staphylococcus aureus bacteria or turpentine oil [Antimicrobial peptides labeled with rganisms . Similartine oil . γ-activated cells of mouse macrophage cell line RAW264.7 ( UBI (29–41)  was originally isolated from the cytosolic fraction of IFN-RAW264.7 . Later,  HPLC chromatograms for UBI peptides indicated that the preparations were more than 95% pure. ITLC analysis of the preparation containing radiolabeled peptide showed peptide-labeling yield of 98% after 10 minutes of incubation and these values remained unchanged up to 24 hours . 99mTc-labeled UBI peptides was assessed by incubating one volume of the labeling solution with one volume of 20% (v/v) human serum in saline for 1 and 24 hours at 37°C. Next, the amounts of free pertechnetate and 99mTc-peptide in the samples were determined by ITLC using methyl ethyl ketone as eluent. Results showed minimal release of radioactivity from the 99mTc-UBI peptides. ITLC analysis of the samples after 1 and 24 hours of incubation in human serum revealed small amounts of released/free 99mTc  [ Stability of the tervals) . 99mTC-UBI is associated with blood cells. Moreover, injection of excess unlabeled UBI 29–41 into Staphylococcus-aureus-infected mice prior to injection of 99mTc UBI 29–41 significantly (P < 0.05) reduced the accumulation of this radiopharmaceutical at the site of infection. In addition, significantly (P < 0.01) higher amounts of 99mTc-UBI 29–41 accumulated at the site of infection in mice using a carrier-free radiolabeled UBI 29–41 as compared with unpurified preparation containing radiolabeled UBI 29–41 [Analysis of murine blood revealed that only a small proportion of the intravenously injected BI 29–41 . in vitro binding of 99mTc-UBI and two different 99mTc-labeled cationic peptides (99mTc-Tat-1-Scr and 99mTc-Tat-2-Scr) to bacteria and to two tumor cell lines (LS174T and ACHN) was performed. The binding of 99mTc-UBI, 99mTc-Tat-1-Scr, and 99mTc-Tat-2-Scr to Staphylococcus aureus was 35%, 78%, and 87%, respectively. While the binding of 99mTc-Tat-1-Scr and 99mTc-Tat-2-Scr was 37% and 33% to colon tumor cells (LS174T) and 39% and 41% to renal tumor cells (ACHN), respectively. Binding of  99mTc-UBI to both cell types was much lower (<4%) [A comparative study of the er (<4%) . 99mTc-labeled UBI peptides to bacteria. The mean ratio between binding of UBI peptides to bacteria and that to leukocytes, determined at 2 and 24 hours, amounted to 73–220 [in vivo specificity of  99mTc-UBI for infection in mice was also evaluated using dual labels in the same animal and comparing the target/nontarget ratio for 67Ga-citrate and 99mTc-UBI at sites of induced infection and sterile inflammation. This study revealed that there is a significant difference (P < 0.05) in the radioactive accumulation of  99mTc-UBI between the sites of infection and inflammation compared to 67Ga-citrate. Thus, 99mTc-UBI showed an average infection/inflammation ratio of 2.08 ± 0.49 compared to 1.14 ± 0.45 for 67Ga-citrate. In conclusion, the in vitro and in vivo results provide evidence that a specific mechanism is responsible for the 99mTc-UBI bacterial intracellular accumulation [Experimental peritoneal infection in mice showed highest binding of mulation .99mTc-labeled UBI peptides visualized the bacterial or fungal infected tissues within 30 minutes after injection. A good correlation between the accumulations of 99mTc-labeled UBI peptides in Staphylococcus-aureus-infected thigh muscles in mice and the number of viable bacteria present at the site of infection was recorded. In immunocompromised animals the accumulation of the peptide at the site of infection seemed to be similar to that in immunocompetent mice, confirming the insignificant contribution of the direct binding of the tracer to infiltrating leucocytes [In experimental animals, various ucocytes . 99mTc-labeled UBI at the site of infection within 15–30 minutes after injection. No significant accumulation of labeled peptide was observed in thighs of rabbits and mice previously injected with LPS or heat-killed bacteria  [3H-deoxyglucose and macrophage accumulation at the site of infection [ Various experimental thigh muscle infections in mice and rabbits with both Gram-positive and Gram-negative bacteria revealed accumulation of mmation) . Only onnfection . 99mTc-labeled UBI peptides are rapidly removed from the circulation via the kidneys. Scintigraphic analysis revealed that, within the first hour after injection of tracer, major part of activity was found in kidneys and urinary bladder with little accumulation in liver, lungs, and spleen  were drawn around source organs  on each time frame. The same set of ROIs was used for all 6 scans and the counts per minutes (cpm) of each ROI were converted to activity using the conjugate view counting method. Counts were corrected by physical decay and by the background correction factor derived from preclinical phantom studies. The image sequence was used to extrapolate 99mTc-UBI time-activity curves in each organ and calculate the cumulated activity. Urine samples were used to obtain the cumulative percent of injected activity versus time renal elimination. The absorbed dose in organs was evaluated according to the general equation described in the MIRD formula. In addition, 67Ga-citrate images were obtained from all the patients and used as a control. Biokinetic data showed a fast blood clearance with a mean residence time of 0.52 hour. Approximately 85% of the injected activity was eliminated by renal clearance 24 hours after 99mTc-UBI administration. Images showed minimal accumulation in nontarget tissues with an average target/nontarget ratio of 2.18 ± 0.74 in positive lesions at 2 hours. All infection positive images were in agreement with those obtained with 67Ga-citrate. The mean radiation-absorbed dose calculated was 0.13 mGy/MBq for kidneys and the effective dose was 4.34 × 10−3 mSv/MBq [ mSv/MBq . Biodist mSv/MBq . 99mTc UBI 29–41 showed good correlation for infection detection in humans when compared with 67Ga imaging of the same subjects [subjects . In anot67Ga scan is nonspecific test which is considered better than other diagnostic techniques. As UBI 29–41 has special affinity for binding to viable bacteria, this has been used for confirmation of vertebral infection which showed 100% sensitivity and 88% specificity [99mTc-UBI 29–41 scan for detection of osteomyelitis were compared. Antimicrobial peptide showed 100% accuracy with maximum mean target to nontarget ratio at 15 minutes after tracer injection, while three-phase bone scan and MRI revealed 90% and 75% accuracy, respectively. This study revealed superiority of antimicrobial peptide imaging over bone scan and MRI [This peptide yielded fast and promising results in patients with suspected mediastinitis after cardiac surgery. Qualitative analysis correctly identified infection in 5/6 patients with proven mediastinitis on bacterial culture . Fever ocificity . Noninva and MRI . 99mTc UBI 29–41 to viable bacteria is proportional to their number in the infective focus. Intensity of tracer uptake decreased when number of viable bacteria was reduced. Therefore it was concluded that this tracer can be used for monitoring efficacy and duration of treatment [As mentioned in animal studies, binding of reatment , 144. Sireatment . 99mTc-labeled antimicrobial peptides bind to fungi in addition to bacterial cell membranes; however, infection either from bacteria or fungi can be differentiated from sterile inflammatory sites [Staphylococcus aureus showed more uptake than Escherichia coli which may be due to different mode of toxicity [ry sites . Similartoxicity . Radiolabeled peptides bind to the cell membranes of the bacteria. However, if the bacteria are engulfed by the anti-inflammatory cells or become intracellular after invasion of the host immune cells, their detection would become difficult with scintigraphy . Staphylococcus aureus [Major concern with use of the labeled antibiotics as specific infection localization tracers is the development of resistance. Similar situation may also be encountered with antimicrobial peptides. Some Gram-negative bacteria can modify the lipid-A moiety of the endotoxin . Similars aureus . Inactivs aureus . However99mTc-ciprofloxacin in sterile inflammation is also a big disadvantage [The medical community often faces the dilemma of discrimination between infection and inflammation on medical as well as on surgical floors. Nonspecific radiotracers for localization of infection/inflammation do not solve the problem. Among the specific radiotracers for localization of infection, antibiotics gained more popularity due to easy availability, labeling, low cost, and high sensitivity. Among the labeled antibiotics ciprofloxacin was the most successful specific bacterial localization agent which showed sensitivity of 85.4% and specificity of 81.7% . Howeverdvantage . Due to dvantage .Candida albicans and Aspergillus Fumigatus infections. The amount of radiolabeled peptides at the site of infection depends on the number of viable organisms present at the focus. Recently investigated antimicrobial peptide, ubiquicidin UBI (29–41) has shown encouraging results in human clinical trials. This peptide can also be used for monitoring efficacy and duration of antibiotic treatment in patients which is very important issue from prophylactic, therapeutic, and socioeconomic point of view. No doubt, there are limitations attributed to synthesis/isolation of such peptides, labeling with isotopes, minimum detection limit of 103 Colony-Forming Unit (CFU) of bacteria, and inability to distinguish between bacterial and fungal infections. In addition, different bacterial types reveal different tracer accumulation (Staphylococcus aureus versus Escherichia coli). Currently no evidence regarding resistance against antimicrobial peptides has been reported. Considering the merits and demerits of radiolabeled peptides and radiolabeled antibiotics, it can currently be concluded that radiolabeled peptides are better specific infection localizing agents. On the other hand, antimicrobial peptides labeled with isotopes are better specific infection localizing agents as they bind specifically to bacterial cell membranes. These tracers detect Gram-positive, Gram-negative bacteria,


Dick Menzies and colleagues report findings from a collaborative, individual patient-level meta-analysis of treatment outcomes among patients with multidrug-resistant tuberculosis. Treatment of multidrug resistant tuberculosis (MDR-TB) is lengthy, toxic, expensive, and has generally poor outcomes. We undertook an individual patient data meta-analysis to assess the impact on outcomes of the type, number, and duration of drugs used to treat MDR-TB.Three recent systematic reviews were used to identify studies reporting treatment outcomes of microbiologically confirmed MDR-TB. Study authors were contacted to solicit individual patient data including clinical characteristics, treatment given, and outcomes. Random effects multivariable logistic meta-regression was used to estimate adjusted odds of treatment success. Adequate treatment and outcome data were provided for 9,153 patients with MDR-TB from 32 observational studies. Treatment success, compared to failure/relapse, was associated with use of: later generation quinolones, (adjusted odds ratio [aOR]: 2.5 [95% CI 1.1–6.0]), ofloxacin (aOR: 2.5 [1.6–3.9]), ethionamide or prothionamide (aOR: 1.7 [1.3–2.3]), use of four or more likely effective drugs in the initial intensive phase (aOR: 2.3 [1.3–3.9]), and three or more likely effective drugs in the continuation phase (aOR: 2.7 [1.7–4.1]). Similar results were seen for the association of treatment success compared to failure/relapse or death: later generation quinolones, (aOR: 2.7 [1.7–4.3]), ofloxacin (aOR: 2.3 [1.3–3.8]), ethionamide or prothionamide (aOR: 1.7 [1.4–2.1]), use of four or more likely effective drugs in the initial intensive phase (aOR: 2.7 [1.9–3.9]), and three or more likely effective drugs in the continuation phase (aOR: 4.5 [3.4–6.0]).In this individual patient data meta-analysis of observational data, improved MDR-TB treatment success and survival were associated with use of certain fluoroquinolones, ethionamide, or prothionamide, and greater total number of effective drugs. However, randomized trials are urgently needed to optimize MDR-TB treatment.Please see later in the article for the Editors' Summary. Mycobacterium tuberculosis, the bacterium that causes tuberculosis, is spread in airborne droplets when people with the disease cough or sneeze and usually infects the lungs (pulmonary tuberculosis). The characteristic symptoms of tuberculosis are a persistent cough, weight loss, and night sweats. Tuberculosis can be cured by taking several powerful antibiotics regularly for at least 6 months. The standard treatment for tuberculosis comprises an initial intensive phase lasting 2 months during which four antibiotics are taken daily followed by a 4-month continuation phase during which two antibiotics are taken. However, global efforts to control tuberculosis are now being thwarted by the emergence of M. tuberculosis strains that are resistant to several antibiotics, including isoniazid and rifampicin, the two most powerful, first-line (standard) anti-tuberculosis drugs.In 2010, 8.8 million people developed tuberculosis—a contagious bacterial infection—and 1.4 million people died from the disease. Although multi-drug resistant tuberculosis (MDR-TB) can be cured using second-line anti-tuberculosis drugs, these are more expensive and more toxic than first-line drugs and optimal treatment regimens for MDR-TB have not been determined. Notably, there have been no randomized controlled trials of treatments for MDR-TB. Such trials, which compare outcomes  among patients who have been randomly assigned to receive different treatments, are the best way to compare different anti-tuberculosis drug regimens. It is possible, however, to get useful information about the association of various treatments for MDR-TB with outcomes from observational studies using a statistical approach called “individual patient data meta-analysis.” In observational studies, because patients are not randomly assigned to different treatments, differences in outcomes between treatment groups may not be caused by the different drugs they receive but may be due to other differences between the groups. An individual patient data meta-analysis uses statistical methods to combine original patient data from several different studies. Here, the researchers use this approach to investigate the association of specific drugs, numbers of drugs and treatment duration with the clinical outcomes of patients with pulmonary MDR-TB.The researchers used three recent systematic reviews  to identify studies reporting treatment outcomes of microbiologically confirmed MDR-TB. They obtained individual patient data from the authors of these studies and estimated adjusted odds (chances) of treatment success from the treatment and outcome data of 9,153 patients with MDR-TB provided by 32 centers. The use of later generation quinolones, ofloxacin, and ethionamide/prothionamide as part of multi-drug regimens were all associated with treatment success compared to failure, relapse or death, as were the use of four or more likely effective drugs (based on drug susceptibility testing of mycobacteria isolated from study participants) during the initial intensive treatment phase and the use of three or more likely effective drugs during the continuation phase. The researchers also report that among patients who did not die or stop treatment, the chances of treatment success increased with the duration of the initial treatment phase up to 7.1–8.5 months and with the total duration of treatment up to 18.6–21.5 months.These findings suggest that the use of specific drugs, the use of a greater number of effective drugs, and longer treatments may be associated with treatment success and the survival of patients with MDR-TR. However, these findings need to be interpreted with caution because of limitations in this study that may have affected the accuracy of its findings. For example, the researchers did not include all the studies they found through the systematic reviews in their meta-analysis , which may have introduced bias. Moreover, because the patients included in the meta-analysis were treated at 32 centers, there were many differences in their management, some of which may have affected the accuracy of the findings. Because of these and other limitations, the researchers note that, although their findings highlight several important questions about the treatment of MDR-TB, randomized controlled trials are urgently needed to determine the optimal treatment for MDR-TB.http://dx.doi.org/10.1371/journal.pmed.1001300.Please access these Web sites via the online version of this summary at tuberculosis, including MDR-TB; its guidelines for the programmatic management of drug-resistant tuberculosis are availableThe World Health Organization provides information on all aspects of tuberculosis, including information on the treatment of tuberculosis and on MDR-TBThe US Centers for Disease Control and Prevention has information about tuberculosis, including a drug-resistant tuberculosis visual tourThe US National Institute of Allergy and Infectious Diseases also has information on all aspects of tuberculosis (in English and Spanish)MedlinePlus has links to further information about TB & ME, a collaborative blogging project run by patients being treated for multidrug-resistant tuberculosis and Medecins sans Frontieres, provides information about MDR-TB and patient stories about treatment for MDR-TBTuberculosis Survival Project, which aims to raise awareness of tuberculosis and provide support for people with tuberculosis, also provides personal stories about treatment for tuberculosisThe  The increasing incidence of multidrug resistant tuberculosis (MDR-TB), defined as resistance to at least isoniazid and rifampin, is a major concern for TB control programs worldwide. MDR-TB treatment requires prolonged use of multiple second-line anti-TB drugs, which are more expensive and toxic than first-line drugs, yet less efficacious Three systematic reviews have recently examined determinants of treatment outcomes in MDR-TB Even in the absence of randomized trials, an individual patient data meta-analysis of observational data offers potential benefits. Detailed patient level information can be used to estimate associations of treatment factors with outcomes, stratified by important covariates, within restricted sub-groups, or adjusted for covariates in meta-regression. We conducted an individual patient data meta-analysis using patient level data combined from different centers, using methods suggested by the Cochrane group The studies considered for this individual patient data meta-analysis were identified from published original studies included in three recent systematic reviews of MDR-TB treatment outcomes Letters describing the meta-analysis were communicated to all corresponding authors of eligible studies. The McGill investigators signed formal data sharing agreements with all collaborating investigators regarding sharing of results, publications, and “ownership” of the data. This project was approved by the Research Ethics Board of the Montreal Chest Institute, McGill University Health Centre, and when deemed necessary by local ethics boards of originally approved studies.Each author provided center-level information such as diagnostic laboratory methods, treatment regimen doses and supervision, and outcome definitions. Regimens were considered individualized if regimens were tailored to individual patients' characteristics such as prior therapy, or drug susceptibility testing (DST) results. Authors also provided de-identified patient level information including age, sex, HIV infection, site of disease, results of chest x-ray, acid fast bacilli (AFB) smear, culture, and DST for first and second-line drugs, drugs used and duration for initial and continuous phases of treatment, surgical resection, and outcomes, including adverse events that required a change in therapy. Treatment outcome definitions provided by each author were compared to the consensus definitions published by Laserson et al. Authors were contacted to request additional data and clarify variable definitions and coding. Variables from each original dataset were extracted, their meaning and coding verified, then mapped to a common set of variables for all patients. Hence datasets from each center had the same variables for all patients, but each dataset was kept distinct. As a final verification, the clinical characteristics of each study population were compared with the original published papers.death; and (iii) treatment failure, relapse, death or default. For duration of therapy, comparisons (ii) and (iii) were not analyzed because in studies with individualized therapy the planned duration was not recorded—only the actual duration, which was truncated by default or death during treatment.We considered three types of drug-exposure in our meta-analysis: (i) specific drugs administered (grouped as suggested by WHO We used random effects (random intercept and random slope) multi-variable logistic regression estimated via penalized quasi-likelihood , and past history of TB treatment . Analyses were performed in all patients and in subgroups—stratified or restricted by important covariates. We tested for the interaction between previous treatment with second-line TB drugs and the number of drugs and duration of treatment in the intensive and continuation phases, respectively. In secondary analyses we included more than one treatment parameter (up to four drugs at once), and individual drugs with treatment duration. For the multivariable analyses only, missing values of these five clinical covariates were imputed using means of patients at the same center with non-missing information. Sex was missing in three patients, age was missing in 27, HIV was missing in 1,271(14%), history of past TB treatment missing in 443 (5%), history of past second-line drug use 758 (8%), and extent of disease information missing in 174 (2%). We assessed whether findings were altered when missing values were estimated using a different method of probabilistic imputation, in secondary analysis I2 and its associated 95% CI Additionally, heterogeneity was explored visually using Forest plots of study specific estimates, and estimated quantitatively via the We identified 67 unique cohorts from the three previous systematic reviews of MDR-TB. Of these, 35 datasets were not used for reasons summarized in The included studies originated from 23 countries, from all WHO health regions. Final sample sizes included in the analysis ranged from 18 to 2,174 patients. In the supplement are summarized: study and center characteristics , excludeAs seen in Patients with prior treatment with second-line drugs were significantly less likely to have HIV co-infection, but were more likely to have cavitary disease, and strains with resistance to other first-line drugs . In thesp = 0.01), and in the initial intensive phase (p = 0.05) (As shown in  = 0.05) . In furt = 0.05) .Among those who did not die or default, odds of treatment success increased with longer duration of the initial intensive phase up to the duration of 7.0 to 8.4 mo , althougAs a sensitivity analysis, all analyses reported in To our knowledge this is the largest combined analysis of treatment of MDR-TB, and the first individual patient data meta-analysis of treatment outcomes in drug resistant TB. With the detailed individual clinical information for 9,153 patients it was possible to use stratified, restricted, and/or multivariable analyses to control for differences in treatment regimens, drug resistance patterns, prior treatment histories, and other patient characteristics such as HIV co-infection. Overall treatment results were poor—treatment success was achieved in only slightly more than half of all patients. Treatment success was significantly associated with specific durations, number of likely effective drugs for the initial intensive and continuation phases of therapy, and with use of later generation quinolones , ofloxacin or ethionamide/prothionamide. These results helped to inform the forthcoming revised MDR-TB treatment guidelines of WHO, and should be useful in planning therapy for individual patients.We suggest cautious interpretation of these results in light of a number of important limitations. First, we included only 32 studies out of a possible 67 series that had reported outcomes of MDR-TB treatment and were identified in three systematic reviews. This selection may have introduced some bias, although as seen in Relapse was ascertained in only 14 studies, which could result in an over-estimate of treatment success. As seen in This analysis suggests that it would be appropriate to use at least four likely effective drugs in the initial intensive phase and at least three likely effective drugs in the continuation phase. However, it is important to underline that this analysis was restricted to cohorts of patients in whom drug susceptibility testing was routinely performed. These results may not apply when standardized regimens are used without routine drug susceptibility testing. We had to base analysis of likely effective drugs on drug susceptibility testing only, because of limited information on the specific drug regimen for many of the previously treated patients. Hence caution is warranted given the well-known limitations of drug susceptibility testing for many of the drugs used, since prior use of these drugs may increase the likelihood of resistance, even if the laboratory result indicates susceptibility.The highest odds of success were associated with duration of the initial intensive phase of 7–8.4 mo, and with a total duration of 18–20 mo. However, particular caution should be used for the interpretation of these results. First we did not have data on duration of therapy with individual drugs, only the different phases of treatment. Second, duration of therapy was individualized for most patients, based upon severity of disease, prior therapy, drug resistance patterns, response to therapy, and timing of sputum conversion. Hence duration of treatment may have been prolonged in patients with worse disease—as suggested in Despite these limitations there were a number of important strengths. A large number of centers, from many different regions of the world, contributed clinical information on a large number of individual patients, allowing a detailed and comprehensive analysis. There was substantial variation in treatment given by different centers, only partially explained by patients' characteristics. In some centers this variation reflected availability of medications, but in other centers this likely reflected individual providers' preferences. This substantial variation in treatment approach would have been much less likely in patients treated at a single center, and enhanced our ability to assess the independent effect of treatment factors on patient outcomes.This individual patient data meta-analysis of 9,153 patients suggests that treatment of MDR-TB should include a later generation quinolone, and ethionamide or prothionamide. In patients who have not received second-line drugs before, the optimal number of likely effective drugs appears to be at least four in the initial intensive phase, and at least three in the continuation phase. The duration of therapy associated with highest odds of success was 7–8.5 mo for the initial intensive phase, and 25–27 mo for total duration. In view of the serious limitations of this observational data, these findings should be considered to have highlighted several important questions for future clinical trials. These questions include the role and choice of injectables, the optimal duration of an injectable and total therapy, and the potential value of later generation quinolones as well as certain group 4 and group 5 drugs. Randomized trials are urgently needed to address these questions and determine the optimal treatment regimens for MDR-TB patients.Alternative Language Abstract S1Chinese translation of the abstract by C-YC and Yuhong Liu.(DOCX)Click here for additional data file.Alternative Language Abstract S2French translation of the abstract by JR.(DOCX)Click here for additional data file.Alternative Language Abstract S3German translation of the abstract by CL.(DOCX)Click here for additional data file.Alternative Language Abstract S4Italian translation of the abstract by GS and GBM.(DOCX)Click here for additional data file.Alternative Language Abstract S5Korean translation of the abstract by T-SS, W-JK, and J-JY.(DOCX)Click here for additional data file.Alternative Language Abstract S6Spanish translation of the abstract by DP, MLGG, JS-O, AP-d-L, MHV, and CP-G.(DOCX)Click here for additional data file.Alternative Language Abstract S7Japanese translation of the abstract by MN and YS.(DOCX)Click here for additional data file.Alternative Language Abstract S8Russian translation of the abstract by DM.(DOC)Click here for additional data file.Table S1(a) Overview of settings of 32 studies included in individual patient data meta-analysis of MDR-TB supplemental tables (for on-line supplement—references for included studies are found in main text. (b) Overview of 35 studies excluded from individual patient data meta-analysis of MDR-TB.(DOC)Click here for additional data file.Table S2Dosages of drugs used for MDR-TB treatment at sites of studies included in individual patient data meta-analysis on MDR-TB supplemental tables (for on-line supplement—references for included studies are found in main text.(DOC)Click here for additional data file.Table S3Summary of treatment outcome definitions used in studies included in individual patient data meta-analysis.(DOC)Click here for additional data file.Table S4Characteristics of patients associated with history of prior TB therapy.(DOC)Click here for additional data file.Table S5Association of Individual drugs with treatment success (compared to failure/relapse)—stratified by history of previous treatment.(DOC)Click here for additional data file.Table S6Secondary analyses to assess impact of covariates on duration of therapy. (A) Duration analysis also adjusted for use of four drugs. (B) Analysis restricted: excluded patients who received two or more injectables, and/or had a serious adverse event to an injectable . (C) Restricted analyses: use of second-line drugs only. (D) Stratified analysis: by use of later generation quinolones: 204 patients receiving first-line drugs only excluded.(DOC)Click here for additional data file.Table S7Pooled outcomes—studies stratified by study level factors .(DOC)Click here for additional data file.Table S8(a) Assessment of potential confounding of clinical characteristics and drug resistance with initial duration . (B) Assessment of potential confounding of clinical characteristics with total duration of therapy .(DOC)Click here for additional data file.Table S9Summary of variance of estimates—individual drugs with treatment success.(DOC)Click here for additional data file.Table S10Summary of variance of estimates—likely effective drugs with treatment success—during different phases of treatment.(DOC)Click here for additional data file.Table S11Association of number of drugs used and treatment success compared to default only.(DOC)Click here for additional data file.Table S12Summary of variance of estimates—duration of treatment with success versus failure/relapse—patients grouped by treatment history.(DOC)Click here for additional data file.


The value of the 12-lead electrocardiogram (ECG) to provide prognostic information in the deadly and disabling syndrome peripartum cardiomyopathy (PPCM) is unknown.To determine the prevalence of major and minor ECG abnormalities in PPCM patients at the time of diagnosis, and to establish whether there are ECG correlates of persistent left ventricular dysfunction and/or clinical stability at six months of follow up, where available.Twelve-lead ECGs were performed at the point of diagnosis on 78 consecutive women presenting with PPCM to two tertiary centres in South Africa and 44 cases (56%) at the six-month follow up. Blinded Minnesota coding identified major ECG abnormalities and minor ECG changes.2]. The majority of cases  presented in sinus rhythm (mean heart rate 100 ± 21 beats/min). At baseline, at least one ECG abnormality/variant was detected in 96% of cases. Major ECG abnormalities and minor changes were detected in 49% (95% CI: 37–60%) and 62% (95% CI: 51–74%) of cases, respectively; the most common being T-wave changes (59%), p-wave abnormality (29%) and QRS-axis deviation (25%).The cohort mainly comprised young women of black African ancestry (90%) [mean age 29 ± 7 years and median body mass index 24.3 (IQR: 22.7–27.5) kg/mp < 0.001) and abnormal QRS axis . On an adjusted basis, major T-wave abnormalities on the baseline 12-lead ECG were associated with lower left ventricular ejection fraction (LVEF) at baseline  and at six months . Similarly, baseline ST-segment elevation was also associated with lower LVEF at six months .Of the 44 cases (56%) reviewed at six months, normalisation of the 12-lead ECG occurred in 25%; the most labile ECG features being heart rate (mean reduction of 27 beats/min; In this unique study, we found that almost all women suffering from PPCM had an ‘abnormal’ 12-lead ECG. Pending more definitive studies, the ECG appears to be a useful adjunctive tool in both screening and prognostication in resource-poor settings. Peripartum cardiomyopathy (PPCM) is a form of heart failure (HF) with poorly understood aetiology, occurring between the last trimester of pregnancy and up to the first five to six months postpartum.8Some studies suggest the incidence of PPCM is one in 3 000 live births. However, one African study found it to be one in 1 000 live births.Definitive diagnosis and subsequent management of PPCM requires a high index of suspicion. It also usually requires referral to a tertiary centre for echocardiographic studies and specialist cardiological management. Anecdotal evidence suggests that many women who initially present with signs and symptoms indicative of PPCM are diagnosed with ‘non-specific symptoms of the puerperal period’. The misdiagnosis of PPCM  represents a clear target for early intervention and prevention. Until specific aetiologies are identified, PPCM remains a diagnosis of exclusion.Women in their peripartum period suspected with PPCM require rigorous investigation; a costly and laborious process for the patient and healthcare provider. This is particularly difficult in a resource-poor environment. Although screening with (point-of-care derived) brain natriuretic peptide (BNP) levels may offer a means of detecting elevated atrial pressures secondary to systolic dysfunction  is common in individuals with HF syndrome, with common anomalies including supraventricular arrhythmias, bundle branch block, and sinus bradycardia.de novo PPCM to two tertiary centres in South Africa  between January 2003 and August 2008 were studied. Patients were referred from primary and secondary health facilities, as well as internally from other departments. Only patients aged ≥ 17 years who fulfilled the diagnostic criteria for PPCM4 were considered eligible for the study. For recruitment, previously describedConsecutive patients presenting with Ethical approval was obtained from each of the local ethical committees of the universities of Cape Town and the Witwatersrand, respectively, prior to the commencement of the study. This study complied with all the requirements of the Declaration of Helsinki. All patients were offered treatment and follow up as per the local standard of tertiary care.n = 34), three patients died (3.9%). Importantly, patients with repeat six-month ECG data did not differ significantly with respect to baseline heart rate, NYHA functional class, and left ventricular ejection fraction (LVEF) from the remaining cohort.A total of 78 women presenting with PPCM were studied. Of these, 56% had follow-up ECG data and were included in the comparative study analyses. Of those patients who had not had six-month ECGs , using the Minnesota code classification system.Standard methods for two-dimensional Doppler transthoracic echocardiography were applied as per the American Society of Echocardiography guidelines.t-tests for normally distributed numerical variables, Mann-Whitney/Wilcoxon signed rank tests for non-parametric paired numerical variables, and chi-squared tests for categorical variables and proportions. Multivariate analysis was conducted using linear and logistic regression for numerical and categorical outcome variables, respectively.All data analyses were performed with STATA-8.Interestingly, no patients under the age of 17 years presented to either study unit and 90% of patients included were young women of African ancestry. Of the 10% that were of non-black African ethnicity, almost all were of mixed ancestry, with only one Caucasian patient. The majority of respondents were normotensive and experienced onset of symptoms in the postpartum period . However, 8% of respondents reported the onset of symptoms prepartum, of which only two were hypertensive .24n = 78). The majority of cases (90%) were in sinus rhythm, although mean heart rate was markedly elevated, with 45% of cases in sinus tachycardia . Only three patients (4%) had completely normal ECGs; excluding those with an elevated heart rate, this increased to nine patients (12%). Overall, 49% (95% CI: 37–60) of cases had a major Minnesota ECG abnormality detected, while 62% (95% CI: 51–74) had a minor ECG variant. A combined total of 63  cases had one or both forms of abnormality detected on their 12-lead ECG. Of the major abnormalities, major T-wave anomalies (38%), followed by abnormal QRS axis (26%) were the most common p = 0.03%) reduction in LVEF compared to those without T-wave changes.Univariate analysis showed no association between LV systolic function and baseline ECG readings. However, on adjustment for age, functional class, echocardiographic LV dimensions, and all the other ECG parameters listed in Table 3, major T-wave abnormalities correlated negatively with left ventricular systolic dysfunction. The presence of major T-wave changes was associated with a clinically relevant 9%  p < 0.001), although 10% still reported functional impairment (NYHA class II or more). Overall, 25% of this sub-set of cases had a normal 12-lead ECG at six months.At six months, a number of clinical parameters had improved in surviving cases subjected to study follow up (p = 0.006) compared to those without T-wave changes at baseline. In addition, ST-segment elevation at baseline was associated with an even greater reduction in LVEF at six months  compared to those without this ECG pattern at baseline.According to univariate analyses, no difference between ‘clinically stable/responded to treatment’ (i.e. recovered LV function) versus non-responders (persistent LV dysfunction) were found in respect of any ECG parameter. However, on an adjusted basis, major T-wave changes and major ST-segment depression found on the baseline 12-lead ECG subsequently correlated with persistently impaired systolic function at six months. Specifically, the presence of major T-wave changes at baseline was associated with a markedly lower LVEF at six months  in detecting underlying LV dysfunction in confirmed cases of de novo PPCM in African women. This would require a high underlying level of ECG abnormalities in such a cohort in order to discriminate against (presumably) more normal 12-lead ECGs in African women experiencing healthier pregnancies.To the best of our knowledge, this is the first study to systematically describe the 12-lead ECG in Of the 78 cases studied, 49% demonstrated major ECG abnormalities, usually associated with significant underlying cardiac pathology, while 62% demonstrated one or more forms of minor variation/abnormality, potentially indicative of the same. We also attempted to examine whether the 12-lead ECG is a useful tool for discriminating between those cases who respond to treatment  and those who had persistent LV dysfunction. In this respect, we found that the presence of two major abnormalities (T-wave inversion and ST-segment depression) and a third Minnesota code criterion not listed as one of the major or minor criteria (ST-segment elevation) found on the baseline 12-lead ECG correlated with persistently poor LV systolic function at six months. T-wave inversion also correlated with LV systolic function at baseline.Typically, LV systolic functional recovery in PPCM is a slow and drawn-out process that enters the second year of treatment.Our findings and the overall utility of the 12-lead ECG in this clinical setting require careful interpretation when fundamental investigations such as echocardiography remain inaccessible to most hospitals and patients in sub-Saharan Africa. Serum levels of NT-proBNP are known to strongly predict the degree of heart failure,26The scarcity of the serum NT-proBNP test in our setting almost mandates using something as inexpensive and easy as the 12-lead ECG to screen for PPCM, even if its sensitivity and specificity prove to be imperfect. These data will be particularly useful if . In Western countries, major ST-segment depression and T-wave abnormalities are often regarded as indications of myocardial ischaemia, bearing consistent prognostic significance for cardiovascular disease mortality across prospective studies, especially for men.28We remain wary of the fact that gender differences in ECG findings often show women to have a higher prevalence of ST-segment depression or T-wave changes, such as to question the true significance of any association between ST-segment depression and T-wave abnormalities with coronary heart disease (CHD) mortality in women.19Studies reporting on the ECG in prognostication of PPCM remain scarce, with two from Nigeria suggesting it to be a weak predictor of recovery and long-term prognosis in PPCM.Systematic reports of ECG abnormalities associated with idiopathic dilated cardiomyopathy (IDCM), which bears some resemblance to PPCM, are few. One such study of IDCM reported that the ECG was found to be normal in up to 25% of affected relatives of IDCM patients , although these were not all newly diagnosed IDCM cases.It remains fair to say that the shortage of studies systematically reporting on the prevalence of ECG anomalies in PPCM may account for most for our inability to corroborate our findings with other available evidence, yet no reports contradict our findings. Overall, therefore, our data can only suggest that the 12-lead ECG in PPCM may be sensitive to underlying LV dysfunction and/or that it can serve as a marker of more extensive cardiac insult early in the disease process.Lastly, we note that the 1% prevalence of first-degree heart block, usually not considered to bear any significant risk to adverse CVD outcome, except for its association with lamin A/C mutation in familial DCM, may in our PPCM cohort merely reflect the 1–2% prevalence in normal young adults.Furthermore, evaluation of this conduction disorder may be of particular importance in PPCM, in view of several reports of first-degree AV block being among one of the earliest signs of lamin A/C mutation, which in turn commonly leads to a phenotype of apparently unexplained DCM.This pilot study has a number of limitations that require comment. Firstly, the Minnesota code may not be sufficiently validated for the detection of heart disease in pregnant women. Moreover, the ‘normal’ 12-lead ECG in African women is yet to be definitively described. Whether the combined presence (81% of cases) of major abnormalities and minor variations is sufficient to support further investigation of the 12-lead ECG as a screening tool , is open to debate.In determining the sensitivity of ECG changes over time, relative to underlying LV dysfunction, we had valid data for only 56% of the cohort. Although our PPCM patients who did not have follow-up ECGs did not differ in clinical and echocardiographic outcome from those with follow-up data, the possibility that the former group may have been clinically worse off than those with six-month data cannot be excluded, given that greater proportions of the former manifested minor T-wave anomalies, and that their left ventricular diameters and BMI at baseline appeared greater than those who had six-month ECGs. However, in light of the lower prevalence of QRS-axis deviation and bundle branch block among the former group, interpretation of the similarity of patients with and without follow up with regard to ECG characteristics becomes speculative.Further data are required to better characterise the 12-lead ECG as a marker of LV dysfunction in this specific clinical (and ethnic) context, before any firm recommendations can be made in respect of obtaining a 12-lead ECG at the conclusion of each pregnancy in sub-Saharan Africa.Despite a number of limitations, this still represents a unique study that will prove to be invaluable in determining the future role of the 12-lead ECG as an inexpensive and simple ‘rule-out’ screening tool for PPCM, and perhaps an important tool for increasing the intensity of subsequent treatment and management. Overall, we found the majority (96%) of PPCM patients presented with ‘abnormal’ 12-lead ECGs, which improved significantly to 75% after the first six months of treatment. Over 80% of patients displayed either major abnormalities or minor variations using the Minnesota code. Of these, sinus tachycardia and QRS-axis deviation were most likely to be attenuated after six months. Even though these ECG abnormalities were mostly non-specific and similar to those of other dilated cardiomyopathies, our study further suggests the ECG to be useful in simple monitoring of clinical progress during treatment and prognostication.Specifically, the baseline presence of major T-wave and ST-segment abnormalities in the context of PPCM patients may place these patients at similar risk of adverse outcomes to those with myocardial ischaemia. More definitive studies are required to determine if this simple and relatively inexpensive tool will prove to be of particular clinical use in the setting of PPCM. Any progress in this regard will be welcome, given the persistently poor health outcomes associated with PPCM in resource-poor settings.