title: Human herpesvirus 6 DNA in plasma after allogeneic stem cell transplantation: incidence and clinical significance.
abstract: BACKGROUND
  Human herpesvirus 6 (HHV-6) is increasingly recognized as an opportunistic and potentially life-threatening pathogen in recipients of allogeneic stem cell transplants (SCTs).
  
  
  METHODS
  To clarify the incidence and clinical relevance of active HHV-6 infection, serial titers of plasma HHV-6 DNA were determined for 50 allogeneic SCT recipients, using real-time polymerase chain reaction.
  
  
  RESULTS
  HHV-6 DNA was detected in plasma from 24 patients (48%). HHV-6 DNA was most frequently apparent approximately 14-27 days after transplantation. An increased risk of a positive result for HHV-6 DNA was associated with transplantation from an allelic-mismatch donor (P = .02) and administration of steroids (P = .04). Steroid use was associated with high HHV-6 DNA loads (P = .02). High HHV-6 DNA loads were correlated with delayed platelet engraftment (P = .04). Among patients who had positive results for HHV-6 DNA, the HHV-6 DNA load was higher in plasma from those who developed limbic encephalitis (n = 4) (P < .0001).
  
  
  CONCLUSIONS
  Active HHV-6 infection is not rare in SCT recipients. SCT from allelic-mismatch donors is associated with increased risk of active HHV-6 infection. Steroid therapy is associated with not only increased incidence of infection but also accelerated viral replication. Development of limbic encephalitis is associated with high HHV-6 DNA load.
authors.affiliation: Division of Pathogenesis and Disease Control, Department of Infectious Diseases, Oita University Faculty of Medicine, Japan. mogata@med.oita-u.ac.jp
authors.forename: Masao
authors.initials: M
authors.lastname: Ogata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kikuchi
authors.forename: Takako
authors.initials: T
authors.lastname: Satou
authors.forename: Rie
authors.initials: R
authors.lastname: Kawano
authors.forename: Junji
authors.initials: J
authors.lastname: Ikewaki
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kohno
authors.forename: Kenji
authors.initials: K
authors.lastname: Kashima
authors.forename: Eiichi
authors.initials: E
authors.lastname: Ohtsuka
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Kadota
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004279:DNA, Viral / Q000097:blood*; D005260:Female; D015654:Herpesvirus 6, Human / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D015994:Incidence; D020363:Limbic Encephalitis / Q000453:epidemiology / Q000473:pathology / Q000821:virology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D019349:Roseolovirus Infections / Q000453:epidemiology* / Q000821:virology; D033581:Stem Cell Transplantation / Q000009:adverse effects*; D014184:Transplantation, Homologous / Q000009:adverse effects*
chemical_list: D004279:DNA, Viral