This work is a retrospective analysis of 54 adult patients, positive for human herpesvirus 6 (HHV-6) after allogeneic stem cell transplantation.
Viral encephalitis was reported for 10 patients.
Mortality rate was relatively high in this population (1-year overall survival [OS], 38%).
Better OS was associated with CD3+ cell count ≥200/µL at the time of HHV-6 reactivation.
Prospective studies with characterization of HHV-6 immune responses are warranted.