Outcomes of allogeneic hematopoietic stem cell transplantation for acquired pure red cell aplasia.

Acquired pure red cell aplasia (PRCA) affects only the red blood cell lineage and responds to immunosuppressive therapy. Few reports describe the outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for refractory PRCA. This study investigated the outcomes of allo-HSCT for PRCA using Japanese nationwide registry data. Eight patients aged 16 years or older who underwent allo-HSCT for acquired PRCA were analyzed. Median ages at diagnosis of PRCA and HSCT were 39.5 (range 19-68) and 47.5 (range 21-68) years, respectively. Stem cell sources and donors were bone marrow (related, n = 2; unrelated, n = 3), umbilical cord blood (n = 2), and peripheral blood stem cells (related, n = 1). All patients achieved neutrophil engraftment with a median time to engraftment of 21 days. Four patients died within 3 months after HSCT; the causes of death were acute myocardial infarction, thrombotic microangiopathy, capillary leak syndrome, and bacterial pneumonia. The remaining four patients were alive and transfusion-independent at a median follow-up of 99.4 months (range 21-148). Allo-HSCT could be a curative treatment option for refractory PRCA. However, early post-transplant mortality is an obstacle, and thus, optimal transplant procedures should be carefully determined for each patient.