Multiple red cell alloantibodies, including anti-Dib, after allogeneic ABO-matched peripheral blood progenitor cell...

Data on red blood cell (RBC) alloantibody appearance after hematopoietic progenitor cell transplantation (HPCT) from an ABO-matched donor are limited.

A 32-year-old Caucasian man with chronic myeloid leukemia, never transfused, conditioned with BuCy120, received granulocyte-colony-stimulating factor-mobilized peripheral blood progenitor cells from his HLA-identical sister. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine A and methotrexate. The patient engrafted showing complete donor chimerism and developed Grade 3 acute GVHD and subsequently extensive chronic GVHD. He received 2 units of RBCs on Days 13 and 14 without clinical signs of hemolysis.

Patient was 0 Rh-K-JK(a-) and donor was 0 Rh+K-JK(a-). Pretransplant alloantibody screening was negative in the patient. In the donor, anti-E was detected before donation, together with anti-Jka and anti-Dib 4, 9, and 12 months after donation, likely triggered by RBC transfusion 2 months before cell harvest. In the patient, anti-Jka was detected on Day +25 and later anti-E and anti-Dib as well. In both, a Dia/Dia genotype was identified. Both parents were Di(a+b+).

Three kinds of non-ABO alloantibodies were detected, including anti-Dib described for the first time after HPCT. The rapid development of antibodies in the recipient despite intensive immunosuppression suggests their production by the donor cells primed by the RBC transfusion before HPC harvest. Their production by the residual host cells cannot be unequivocally excluded, however.