Clinical Features and Risk Factors of Pure Red Cell Aplasia Following Major ABO-Incompatible Allogeneic Hematopoietic Stem Cell Transplantation.

Objective:To study the incidence, risk factors, clinical outcome, management and prevention of pure red cell aplasia (PRCA) following major ABO-incompatible allogeneic hematopoietic stem cell transplantation (allo-HSCT).

Method:We retrospectively analyzed 11 cases of PRCA from a series of 42 patients undergoing major ABO-incompatible allo-HSCT from April, 1997 to December, 2005.

Results:1. 11 out of the 42 patients developed PRCA (26.1%); 2. All the 11 cases of PRCA were in blood group O recipients of grafts from blood group A donor (n=9) or blood group B donor (n=2). 3. The following factors were associated with an increased risk of PRCA:(1) blood group O recipient;(2) blood group A donor;(3) blood group O/A in recipient/donor pair;4. Only blood group O/A in recipient/donor pair was identified as being significantly associated with the occurrence of PRCA by multivariate analysis (P=0.006); 5. 6 patients who received donor-type plasma exchange did not develop PRCA, and among them, 5 cases were the O blood group recipients. 8 patients obtained spontaneous remission and in the remaining 3 patients, 2 patients with long-lasting PRCA were successfully treated with plasma exchange with donor-type plasma replacement and the other one who was also complicated by EBV-associated lymphoproliferative disorder (EBV-PTLD) responded rapidly to anti-CD20 monoclonal antibody and achieved complete resolution of clinical finding and symptom of both EBV-PTLD and PRCA.

Conclusions:The incidence of PRCA in this series of patients was 26.1%. Only blood group A/O in donor/recipient pair is identified as being significantly associated with the occurrence of PRCA by multivariate analysis. Donor-type plasma exchange is an effective approach for the treatment and prophylaxis of PRCA. Anti-CD20 monoclonal antibody is indicated for patients who are not response to conventional therapy.