Steroid Responsiveness and Clinical Outcomes in Diamond–Blackfan Anemia: Analysis From the Canadian Inherited Marrow Failure Registry

Diamond-Blackfan anemia (DBA) is a rare inherited bone marrow failure syndrome characterized by erythroid aplasia, congenital anomalies, and cancer predisposition. Although corticosteroids are the standard first-line therapy for transfusion-dependent patients, treatment response varies, and reliable predictors remain undefined. We retrospectively analyzed data from the Canadian Inherited Marrow Failure Registry to identify clinical and genetic factors associated with steroid responsiveness. Among 80 patients with evaluable steroid response, 30 were classified as the responder group and 50 as the non-responder group (non-response or loss of response after initial improvement). The median age at diagnosis was significantly higher in the responder group than in the non-responder group (20 months vs. 3 months, p = 0.004). ROC curve analysis showed that age at diagnosis had predictive value for steroid responsiveness, with an optimal cutoff of 9.5 months. DBA-associated genetic mutations were identified in 58 patients. Notably, RPL5 mutations were significantly more frequent in the non-responder group than in the responder group (22.0% vs. 0%, p = 0.004). No significant difference in overall survival was observed between the responder and non-responder groups. Differences in corticosteroid response were associated with diagnostic age and specific genetic variants, offering potential guidance for individualized treatment decisions.