Long-term prognosis of human herpesvirus 6 reactivation following allogeneic hematopoietic stem cell transplantation.
BACKGROUND
Patients undergoing hematopoietic stem cell transplantation (HSCT) frequently have HHV-6 reactivation typically during the early phase following HSCT. The long-term clinical complications and prognosis, however, remain unclear.


METHODS
Between September 2010 and October 2012, whole blood samples from 105 patients collected weekly from prior to 6 weeks after HSCT underwent multiplex polymerase chain reaction (PCR) to screen for viral DNA, followed by real-time PCR for quantitative estimation. In 48 patients, only HHV-6 was detected in at least one sample. In 30 patients, no viral DNA was detected. Long-term clinical records were reviewed in March 2016. All 48 HHV-6-positive patients, and 24 patients in whom no viral DNA detected, were followed up.


RESULTS
Median maximum HHV-6 DNA load in the blood of the HHV-6 reactivation group (n = 48) was 11 800 copies/μg peripheral blood leukocyte DNA (range, 52-310 000 000). Hemophagocytic syndrome (HPS) was diagnosed in two subjects with HHV-6 reactivation. Acute graft-versus-host disease (GVHD) developed more frequently in patients with HHV-6 reactivation than in patients without viral reactivation (P = 0.002), but there was no difference in incidence of chronic GVHD. There was no difference in engraftment of neutrophils and platelets between groups. There was also no difference in overall survival between groups. Onset of HPS, however, was associated with lower overall survival (P = 0.009).


CONCLUSIONS
Human herpesvirus 6 reactivation was associated with acute GVHD, but not with chronic GVHD, engraftment or overall survival. Onset of HPS, however, predicts lower overall survival.
['Iesato|Kotoe|K|http://orcid.org/0000-0002-1859-157X', 'Hori|Tsukasa|T|', 'Yoto|Yuko|Y|http://orcid.org/0000-0002-9728-8463', 'Yamamoto|Masaki|M|http://orcid.org/0000-0002-0288-7990', 'Inazawa|Natsuko|N|', 'Kamo|Kenichi|K|', 'Ikeda|Hiroshi|H|', 'Iyama|Satoshi|S|', 'Hatakeyama|Naoki|N|', 'Iguchi|Akihiro|A|', 'Sugita|Junichi|J|', 'Kobayashi|Ryoji|R|', 'Suzuki|Nobuhiro|N|', 'Tsutsumi|Hiroyuki|H|http://orcid.org/0000-0002-8674-0979']
D000293:Adolescent D000328:Adult D000368:Aged D002648:Child D002675:Child, Preschool D005260:Female D005500:Follow-Up Studies D006086:Graft vs Host Disease D018380:Hematopoietic Stem Cell Transplantation D015654:Herpesvirus 6, Human D006801:Humans D007223:Infant D008297:Male D008875:Middle Aged D017063:Outcome Assessment, Health Care D011379:Prognosis D011446:Prospective Studies D012189:Retrospective Studies D012307:Risk Factors D019349:Roseolovirus Infections D015996:Survival Rate D055815:Young Adult
human herpesvirus 6 hematopoietic stem cell transplantation hemophagocytic syndrome graft-versus-host disease overall survival