title: Long-term outcome of human herpesvirus-6 encephalitis after allogeneic stem cell transplantation.
abstract: Human herpesvirus-6 (HHV-6) encephalitis is recognized as a relatively rare, but sometimes lethal, complication of allogeneic hematopoietic stem cell transplantation (HSCT). Although the development of new diagnostic techniques and antiviral therapy has improved, the prognosis of encephalitis is still unclear. We surveyed 197 patients who underwent allogeneic HSCT between January 2004 and March 2008 at our institution, and 8 (4.0%) were diagnosed as having HHV-6 encephalitis. Five were male and 3 were female, with a median age of 40.5 years. The median onset of HHV-6 encephalitis was 18 days after HSCT, and the median duration of antiviral therapy was 41 days. The median survival time from the onset of encephalitis was 23.1 months (range: 2.7-66.7), and 3 patients died of unrelated causes (sepsis in 2 and gastrointestinal tract bleeding in 1). Cord blood transplantation was identified as the only independent risk factor (relative risk [RR] = 4.98; P = .049) by multivariate analysis. There was no statistical significance of survival after HSCT between the patients with HHV-6 encephalitis and those without HHV-6 encephalitis (the 2-year survival rate was 60% and 52.6%, respectively; P = .617). Four of the 5 surviving patients were unable to return to society because of neuropsychological disorders, including anterograde amnesia and seizures with prominent hippocampal atrophy. Although HHV-6 encephalitis occurring after HSCT is now becoming a curable complication, its sequelae, such as neuropsychological disorders, have a marked influence on the quality of life of long-term survivors. Accordingly, it is necessary to identify risk factors for HHV-6 encephalitis and establish methods for prevention of this complication.
authors.affiliation: Department of Hematology, Yokohama City University Medical Center, Yokohama, Japan. sakarika@urahp.yokohama-cu.ac.jp
authors.forename: Rika
authors.initials: R
authors.lastname: Sakai
authors.forename: Heiwa
authors.initials: H
authors.lastname: Kanamori
authors.forename: Kenji
authors.initials: K
authors.lastname: Motohashi
authors.forename: Wataru
authors.initials: W
authors.lastname: Yamamoto
authors.forename: Shiro
authors.initials: S
authors.lastname: Matsuura
authors.forename: Atsuko
authors.initials: A
authors.lastname: Fujita
authors.forename: Rika
authors.initials: R
authors.lastname: Ohshima
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kuwabara
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Tanaka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fujita
authors.forename: Atsuo
authors.initials: A
authors.lastname: Maruta
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ishigatsubo
authors.forename: Shin
authors.initials: S
authors.lastname: Fujisawa
mesh_terms: D000328:Adult; D000647:Amnesia / Q000209:etiology / Q000821:virology; D002423:Cause of Death; D036101:Cord Blood Stem Cell Transplantation; D003625:Data Collection; D018792:Encephalitis, Viral / Q000150:complications / Q000635:transmission* / Q000821:virology; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D015654:Herpesvirus 6, Human; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012640:Seizures / Q000209:etiology / Q000821:virology; D015996:Survival Rate; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D055815:Young Adult