Background: Human herpesviruses may cause severe complications after allogeneic hematopoietic stem cell transplantation (HSCT). However, the impact of some of these infections on transplant outcomes is still unclear. A prospective survey on the incidence and clinical features of herpesviruses infections after HSCT has not yet been conducted in Brazilian patients, and the impact of these infections on HSCT outcome remains unclear.
Methods: We prospectively analyzed the incidence of infection of the eight human herpesviruses simultaneously in 1 045 peripheral blood samples from 98 allogeneic HSCT recipients. Samples were collected weekly starting at the time of transplant until day +100. All herpesviruses were screened and quantified in plasma by quantitative real-time polymerase chain reaction. Median follow up time was 24 months.
Results: The incidences of infection for each herpesvirus were as follows: cytomegalovirus (CMV), 44%; human herpesvirus [HHV] 6, 18%; HHV8, 6%; Epstein-Barr virus, 3%; herpes simplex virus 1, 3%; varicella zoster virus, 3%; HHV7, 2%; and herpes simplex virus 2, 1%. The CMV infection was significantly more frequent among adults and was associated with a higher risk of developing acute graft-versus-host disease. The HHV6 infection was significantly more frequent after umbilical cord blood transplant and was associated with an increased risk of platelet engraftment failure. There was no significant impact of these infections on the other transplant outcomes.
Conclusions: Herpesviruses infections were uncommon after HSCT, except for CMV and HHV6, which, although relatively frequent, had no clinically relevant impact on the outcomes.