Transmission of integrated human herpesvirus-6 in allogeneic hematopoietic stem cell transplantation

Bone Marrow Transplant. 2007 Sep;40(6):563-6. doi: 10.1038/sj.bmt.1705780. Epub 2007 Jul 16.


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.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Antibodies, Viral / blood
  • DNA, Viral / blood
  • Hematopoietic Stem Cell Transplantation / adverse effects*
  • Herpesvirus 6, Human / genetics*
  • Herpesvirus 6, Human / immunology
  • Herpesvirus 6, Human / isolation & purification
  • Humans
  • Male
  • Middle Aged
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / therapy*
  • Roseolovirus Infections / transmission*
  • Roseolovirus Infections / virology*
  • Tissue Donors
  • Transplantation, Homologous
  • Virus Integration


  • Antibodies, Viral
  • DNA, Viral