Prevalence of Viral Infections and Serious Complications in Pediatric Hematopoietic Stem Cell Transplant Patients: A Ten-Year Single-Institution Retrospective Study

Abstract

Background: Pediatric hematopoietic stem cell transplant (pHSCT) patients are at risk for many life-threatening post-transplant complications, notably relapse, graft-versus-host disease (GvHD), and infection.

Methods: This retrospective study reviewed 10 years of pHSCT at a single institution, assessing for risk factors for post-transplantation viral infections (herpes simplex virus (HSV), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpes virus 6 (HHV6), adenovirus (ADNV), and human polyoma virus 1 (BK virus)), and characterizing adverse infectious outcomes.

Results: Overall, 139 patients received 151 transplants. With respect to graft source: 73 (48.3%) were bone marrow, 67 (44.4%) umbilical cord blood (UCB), and 11 (7.2%) peripheral blood stem cells (PBSCs). Forty-one deaths occurred, for an overall mortality rate of 29.5%. The overall incidence of post-transplant viral infections was 47.7% (n = 72). Incidence of post-transplant infection varied by virus type: 3.97% HSV, 0.67% VZV, 3.97% EBV, 24.5% CMV, 14.5% HHV6, 12.6% ADNV, and 12.6% BK virus. Viral encephalitis, though relatively uncommon, was primarily caused by HHV6 and more common in UCB transplants. Overall, cell source and donor source were identified with statistically significant correlation to both risk of infection and mortality.

Conclusions: Post-transplant viral infection remains as a serious adverse event in pediatric patients, and thus prospective studies should be performed to implement early intervention and more aggressive treatment in select high-risk patients. More studies specifically addressing infection risks in cord blood transplants and risk factors for post-transplant viral encephalitis are warranted.