The impact of alternative donor types on viral infections in pediatric hematopoietic stem cell transplantation

Viral infections remain one of the most important complications following allogeneic HSCT. Few reports compare virus infection between different donor types in pediatric patients. We retrospectively analyzed viral infections and the outcome of one hundred and seventy-one pediatric patients (median 7.38years) who underwent allogeneic HSCT from matched related donor (MRD, n=71), 10 of 10 HLA allele-matched unrelated donors (MUD1; n=29), 9 of 10 HLA allele-matched unrelated donors (MUD2; n=40), and haploidentical donors (n=31). PCR screening for BK virus, adenovirus, Epstein-Barr virus, parvovirus B19, human herpesvirus 6, and CMV were performed routinely weekly. Infections between 0-30, 31-100, and 101days-2years were identified separately. BK virus and CMV reactivations were significantly low in MRD transplant patients (P=.046 and P<.0001, respectively), but incidences of all virus infections between MUD1, MUD2, and haplo-HSCT were found statistically not different. The OS was found to be affected by having one or multiple virus infection (P=.04 and P=.0008). Despite antiviral prophylaxis and treatments, post-transplant viral infections are associated with reduced overall survival. Haplo-HSCT is comparable with MUD transplantation in the setting of viral infections. A larger study group and prospective studies are needed to confirm this observation.