Major central nervous system complications after allogeneic stem cell transplantation: A large retrospective study on 888 consecutive adult patients

Objectives Major complications affecting the central nervous system (CNS) present a challenge after allogeneic stem cell transplantation (allo-SCT). Methods Incidence, risk factors, and outcome were retrospectively analyzed in 888 patients in a monocentric study. Results Cumulative incidence (CI) of major CNS complications at 1 year was 14.8% (95%CI 12.3%-17.2%). Median follow-up is 11 months. CNS complications were documented in 132 patients: in 36 cases, classified metabolic; 26, drug-related neurotoxicity (14 attributed to cyclosporine A, 4 to antilymphocyte globulin); 11, cerebrovascular (ischemic n = 8, bleeding n = 3); 9, infections; 9, psychiatric; and 9, malignant. The cause of CNS symptoms remained unclear for 37 patients (28%). Multivariate analysis demonstrated an association of CNS complication with patient age (P < .001). The estimated OS of patients with any CNS complication was significantly lower than in patients without neurological complications (P < .001), and the CI of non-relapse mortality (NRM) was higher for patients with CNS complication (P < .001). A significant negative impact on survival can only be demonstrated for metabolic CNS complications and CNS infections (NRM,P P = .0003, respectively), and relapse (P < .0001). Conclusion CNS complications after allo-SCT are frequent events with a major contribution to morbidity and mortality. In particular, the situations of unclear neurological complications need to be clarified by intensive research.