Iesato K, et al. - The long-term clinical complications and prognosis among patients undergoing hematopoietic stem cell transplantation (HSCT) experiencing HHV-6 reactivation during the early phase following HSCT were studied. A connection between HHV-6 reactivation with acute graft-versus-host disease (GVHD), but not with chronic GVHD, engraftment, or overall survival was demonstrated. Nonetheless, it was determined that the onset of HP was associated with lower overall survival.