Human herpesvirus 6 infection in autologous bone marrow transplant recipients: A prospective study

After primary infection in early life, human herpesvirus 6 (HHV-6) remains latent in the body and may reactivate in subjects with poor immune status. A 180-day longitudinal study of HHV-6 infection was carried out in 23 autol ogous bone marrow transplant recipients to evaluate reactivation of HHV-6; two of these patients underwent a double transplant. The patients were moni tored prospectively for HHV-6 DNA in peripheral blood mononuclear cells (PB MC) by hot start nested PCR. Positive samples were typed by the enzymatic r estriction protocol. Positive plasma samples were also tested for HHV-6 DNA . Antibodies against HHV-6 were measured by immunofluorescence. Five and tw o out of 23 patients had intermittent and persistent positivity to HHV-6 DN A in PBMCs, respectively; four patients carried variant B, and the other th ree patients both A and B. None of the respective plasma samples were posit ive. Two patients were positive for HHV-6 antibodies. Since the significanc e of HHV-6 DNA in PBMCs is unclear, these findings do not necessarily indic ate active infection but may be due to mild immunosuppression in autologous BMT recipients. J. Med. Virol. 60:39-42, 2000. (C) 2000 Wiley-Liss, Inc.