title: Transmission of integrated human herpesvirus-6 in allogeneic hematopoietic stem cell transplantation.
abstract: Human herpesvirus 6 (HHV-6) viremia, as detected by polymerase chain amplification, occurs in approximately half of allogeneic hematopoietic stem cell transplant recipients. The significance of such viremia is incompletely understood, but HHV-6 encephalitis and bone marrow suppression are increasingly being recognized in patients with high viral DNA. We report two patients in whom donor-to-recipient transmission occurred through hematopoietic transplant by means of chromosomally integrated (CI) HHV-6. Iatrogenic transmission manifested at engraftment as asymptomatic elevation of HHV-6 viral DNA of 3600 and 15 400 DNA copies/ml in plasma and 6.1 x 10(6) and 9.7 x 10(5) DNA copies/ml in the whole blood. Both donors had elevated plasma HHV-6 PCR at 5.6 x 10(4) and 1.3 x 10(5) DNA copies/ml and strikingly elevated whole blood HHV-6 levels at 4.1 x 10(6) and 4.7 x 10(6) DNA copies/ml, respectively. CI of the virus was traced to the mother of one patient and his donor. CI of HHV-6 may confound the interpretation of HHV-6 viremia after stem cell transplantation; consideration of the possibility of CI HHV-6 will avoid unnecessary antiviral therapy.
authors.affiliation: Center for Cell and Gene Therapy, Baylor College of Medicine, The Methodist Hospital, Houston, TX, USA. kamble@bcm.edu
authors.forename: R T
authors.initials: RT
authors.lastname: Kamble
authors.forename: D A
authors.initials: DA
authors.lastname: Clark
authors.forename: H N
authors.initials: HN
authors.lastname: Leong
authors.forename: H E
authors.initials: HE
authors.lastname: Heslop
authors.forename: M K
authors.initials: MK
authors.lastname: Brenner
authors.forename: G
authors.initials: G
authors.lastname: Carrum
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D004279:DNA, Viral / Q000097:blood; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D015654:Herpesvirus 6, Human / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000628:therapy*; D019349:Roseolovirus Infections / Q000635:transmission* / Q000821:virology*; D014019:Tissue Donors; D014184:Transplantation, Homologous; D016662:Virus Integration
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral