Regeneration of peripheral blood cells following ABO incompatible allogeneic bone marrow transplantation for severe aplastic anaemia.

The regeneration of peripheral blood cells in six patients receiving ABO incompatible bone marrow transplants for severe aplastic anaemia has been studied. The results are compared with those of 18 similar aplastic patients treated with ABO compatible transplants. Reticulocyte recovery in the ABO incompatible cases was significantly delayed (P less than 0.01) and associated with greatly prolonged red cell transfusion requirements (P less than 0.001). Peripheral blood regeneration of neutrophils, lymphocytes and platelets was also significantly delayed (P less than 0.01). Platelet support was required for longer in the ABO incompatible cases (P less than 0.001) but there was no increase in the incidence or severity of infections in the post transplant period.