Pure Red Cell Aplasia after ABO-Mismatched Allogeneic Stem Cell Transplantation Treated with Therapeutic Plasma Exchange and Rituximab

• Published in: Blood 2015-12, Vol.126 (23), p.5453-5453
• Main Authors: Karp, Rebecca, Arnason, Jon E., Rosenblatt, Jacalyn, Avigan, David, Joyce, Robin, Nahas, Myrna Rita, Uhlmann, Erik, Hamdan, Ayad
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V126.23.5453.5453

Introduction Pure red cell aplasia (PRCA) is a severe consequence of major and bi-directional ABO-mismatched allogeneic stem cell transplantation (allo-SCT), likely the result of persistent isoagglutinin-producing host plasma cells that have escaped pre-transplant conditioning or graft vs. plasma cell effect (Aung et. al. 2013). PRCA, defined as anemia with reduced reticuloytosis and absence of red cell precursors in the bone marrow at 60 days after transplantation, complicates about 10-20% of all ABO-mismatched allo-SCTs; however, optimal treatment remains unknown. We report 5 cases from our institution of ABO mismatched allo-SCT complicated by PRCA treated with therapeutic plasma exchange (PEX) with or without the anti-CD20 monoclonal antibody rituximab. Report Patient characteristics are shown in Table 1. Indications for transplantation included refractory multiple myeloma, acute myeloid leukemia, and myelodysplastic syndrome (table 1); four of five patients underwent myeloablative conditioning, and the fifth received a reduced-intensity regimen due to age and co-morbidities. Prophylaxis for graft-versus-host disease consisted of cyclosporine alone, cyclosporine and prednisone, or tacrolimus and prednisone. ABO mismatching was major in four patients and bi-directional in one patient; all donors and recipients were Rh(D) positive. In all five patients, neutrophil engraftment occurred between days 11-15 after transplantation, with failure of red cell engraftment by day 60. Response Intervention included PEX in all patients, performed every-other-day (table 1). Three patients also received adjuvant rituximab in addition to PEX. Resolution of PRCA, which we defined as transfusion independence, presence of erythroid precursors on bone marrow biopsy, and Òmixed fieldÓ on blood type crossing, occurred in four out of five patients (mean 95 days). In two patients (patients 3 and 5) PEX and rituximab led to transfusion independence in less than 30 days after initiation of PEX. In one patient (patient 2), red cell engraftment occurred 87 days after initiation of PEX; another patient (patient 4) required 10 sessions of PEX and 2 cycles of rituximab (4 weekly doses separated by 6 months) to achieve transfusion independence 253 days after initiation of PEX. One patient (patient 1) had persistent PRCA despite 10 sessions of PEX and died of disease relapse 398 days after transplantation. In one patient (patient 2), tapering of immunosuppression was attempted in conjunc