Successful treatment with daratumumab for post-HSCT refractory hemolytic anemia.

Autoimmune cytopenias (AIC) following allogeneic hematopoietic stem cell transplantation (HSCT) may cause significant morbidity and mortality and are often challenging to treat. We present a case of a pediatric patient with primary myelofibrosis of infancy caused by VPS45 protein deficiency, who developed severe refractory hemolytic anemia and immune-mediated thrombocytopenia 3.5 months following HSCT. After the failure of several treatments, he received daratumumab, an anti-CD38 specific antibody, and demonstrated fast and sustained response. The only side effect was delayed recovery of humoral immunity. Daratumumab, by targeting antibody-producing plasma cells, may be a valid treatment option for refractory post-HSCT AIC.