Risks and outcomes of invasive fungal infections in recipients of allogeneic hematopoietic stem cell transplants after nonmyeloablative conditioning

The incidence of invasive mold infections has increased during the 1990s among patients undergoing allogeneic hematopoietic stem cell transplantation (HCT) after myeloablative conditioning. In this study, we determined risk factors for invasive mold infection and mold infection-related death among 163 patients undergoing allogeneic HCT with nonmyeloablative conditioning. The cumulative incidence rates of proven or probable invasive fungal infections, invasive mold infections, invasive aspergillosis, and invasive candidiasis during the first year after allogeneic HCT with nonmyeloablative conditioning were 19%, 15%, 14%, and 5%, respectively, which were similar to those after conventional myeloablative HCT. Invasive mold infections occurred late after nonmyeloablative conditioning (median, day 107), with primary risk factors including severe acute graft-versus-host disease (GVHD), chronic extensive GVHD, and cytomegalovirus (CMV) disease. The 1-year survival after diagnosis of mold infections was 32%. High-dose corticosteroid therapy at diagnosis of mold infection was associated with an increased risk for mold infection-related death. Overall, nonrelapse mortality was estimated at 22% (36 patients) after nonmyeloablative conditioning, of which 39% (14 patients) were mold infection-related (9% of the overall mortality). More effective strategies are needed to prevent invasive mold infections, which currently account for a notable proportion of nonrelapse mortality after nonmyeloablative allogeneic HCT.