Delayed erythropoiesis after major ABO-incompatible bone marrow transplantation: report of a case.

Major ABO-incompatible bone marrow transplantation (BMT) may be associated with delayed erythropoiesis. A 38-year-old man (blood group O) with chronic myelogenous leukemia received a BMT from his histocompatibility antigen (HLA) identical brother (blood group A). The pre-BMT anti-A titer of the patient was 1:4. The harvested marrow was depleted of RBC by 6% hydroxyethyl starch sedimentation and Ficoll-Hypaque gradient centrifugation. No acute hemolysis occurred after marrow infusion. Myeloid and megakaryocytic series engrafted promptly. However, delayed erythropoiesis up to day 266 was found. Prolonged presence of anti-A antibody was noted for more than 250 days after BMT, although the peak titer was only 1:8. After the reconstitution of bone marrow, the erythroid series was confirmed as donor origin (RBC cell typing A). It is proposed that the prolonged presence of anti-A antibody probably produced from the residual host B lymphocytes, would destroy the regenerating erythroid precursors. Also, use of cyclosporin A may be associated with higher rates of prolonged production of anti-A/B antibodies and the subsequent delayed erythropoiesis.