Impact of stem cell graft on early viral infections and immune reconstitution after allogeneic transplantation in adults

- HHV-6 and BKPyV DNAemia were significantly higher after dUCB grafts.
- EBV DNAemia were significantly higher after uPBSC grafts.
- ADV DNAemia developed only in dUCB recipients.
- HHV-6 active infections were also higher in the dUCB group.
- Higher counts of B lymphocytes and monocytes were observed in the dUCB group.

BackgroundViral infections are well-known complications after allogeneic stem cell transplant (allo-SCT).ObjectivesWe compared prospectively incidences of DNAemia and active infections (AI) for five opportunistic viruses (Human Herpesvirus 6 (HHV-6), Epstein-Barr virus (EBV), BK polyomavirus (BKPyV), Cytomegalovirus (CMV) and Adenovirus (ADV)) and kinetics of immune reconstitution (IR) in adults receiving either double umbilical cord blood (dUCB group) or unrelated peripheral blood stem cell (uPBSC group) allo-SCT after a reduced-intensity conditioning (RIC) regimen.Study designWhole blood samples were collected at transplant, every 15 days during the first 3 months and at 4, 5 and 6 months post-transplant.ResultsSixty-five patients were enrolled (uPBSC n = 34; dUCB n = 31). Incidences of HHV-6 and BKPyV DNAemia were significantly higher for dUCB (97% vs 23.5% and 58% vs 32%, respectively) while EBV DNAemia was more frequently detected in uPBSC (71% vs 26%). The incidence of CMV DNAemia was similar between both groups. ADV AI developed only in dUCB. HHV-6 AI were also higher in dUCB (84% vs 21%). In multivariate analysis, dUCB graft was the only independent factor associated with HHV-6 DNAemia (OR: 19.0; 95%CI: 5.2-69.1; p < 0.0001) while EBV DNAemia were significantly associated with uPBSC (OR: 29.9; 95%CI: 5.68-158; p < 0.0001). dUCB graft was also the only factor associated with HHV-6 AI. Finally, higher counts and faster recoveries of B lymphocytes (p<0.0001) and monocytes (p = 0.0007) were observed in the dUCB group.ConclusionWe demonstrate a strong correlation between sources of graft and patterns of viral DNAemia and AI and IR after RIC allo-SCT.