Risk factors for late infections after allogeneic hematopoietic stem cell transplantation from a matched related donor.

After allogeneic hematopoietic stem cell transplantation (HSCT), early infections represent a major cause of morbidity and mortality but little information has been previously reported on late infections. Late infection incidence and risk factors were retrospectively determined in 196 long-term survivors after HLA matched related HSCT. Patients transplanted for aplastic anemia, chronic myelogenous leukemia (CML), and acute myelogenous leukemia (AML) were included. Median follow-up was 8 years. Thirty patients died beyond the first year, causes of death were relapse (n = 10) and infections (n = 19, associated with graft-versus-host disease [GVHD] in 16 patients). Late severe bacterial (LSB) and fungal infections occurred in 30 and 8 patients, yielding to an 8-year cumulative incidence of 15 (95%CI: 10-20) and 4% (95%CI: 1-6), respectively. The majority of viral infections were hepatitis C (HCV) and VZV (8-year cumulative incidence: 10 (95%CI: 5-14) and 27% (95%CI: 20-34), respectively. Three risk factors for LSB have been identified in multiple Cox analysis: CMV status (positive recipient and negative donor) (hazard ratio [HR]: 2.5, 95%CI: 1.1-5.9, P = .033), irradiation-based conditioning regimen (HR: 3.1, 95%CI: 1.2-7.8, P = .016), and extensive chronic GVHD (cGVHD; HR: 2.9, 95%CI: 1.3-6.9, P = .013). Extensive cGVHD was the only risk factor for non-HCV viral infections in patients transplanted for AML or CML (HR: 2.7, 95%CI: 1.4-5.1, P = .002). After HSCT, patients remain at high risk of infections even late after transplantation, in particular, with the above risk factors, and required a prolonged follow-up.