Mesenchymal stem cells for the treatment of refractory pure red cell aplasia after major ABO-incompatible hematopoietic stem cell transplantation.

Pure red cell aplasia (PRCA) is a well-known, although infrequent, hematological complication after allogeneic hematopoietic stem cell transplantation (HSCT). PRCA occurs in cases of major ABO mismatch between donor and recipient and is believed to be due to inhibition of donor erythroid progenitors by residual host isohemagglutinins. The purpose of our study was to further evaluate the efficacy of human adipose tissue-derived mesenchymal stem cells (AMSC) as the salvage therapy for refractory PRCA after major ABO-incompatible HSCT. Two patients with refractory pure red cell aplasia received intravenous infusions of AMSC at a dose of 1.5 x 10(6)/kg of the patients' weight, and rapid recovery from PRCA without any side effects was observed. We conclude that AMSC seems to be a promising therapeutic option in patients with PRCA after ABO-mismatched HSCT, in whom conventional treatment fails.