Human herpesvirus 6 infection after autologous or allogeneic stem cell transplantation: A single-center prospective longitudinal study of 92 patients

To determine the incidence and clinical relevance of active human herpesvir us 6 (HHV-6) infection, 92 consecutive unselected recipients of autologous or allogeneic stem cell grafts were investigated in a prospective longitudi nal study. Active infection was assessed by the presence of viral deoxyribo nucleic acid (DNA) in 846 peripheral blood mononuclear cell specimens and 1 15 plasma specimens, by means of a specially developed polymerase chain rea ction designed to avoid detection of latent genome. The incidence of HHV-6 infection observed was 42.5%, irrespective of the type or source of graft, and infection was significantly associated with partial (P = .002) or total myelosuppression (P = .01) and fever (P < .000001). Infusion of bone marro w as the source of graft, reactivation occurring before platelet or neutrop hil engraftment, and presence of HHV-6 DNA in plasma were identified as ris k factors for symptomatic HHV-6 infection (P < .002).