Delayed hemolysis resulting from anti-A₁ after liver transplantation

The authors report a case of a delayed hemolytic transfusion reaction in a type A₂ recipient of a type O liver allograft. An anti-A₁ antibody reactive at 37°C in the indirect antiglobulin test was identified both in the patient's serum and in an eluate. Hemolysis secondary to the production of anti-A₁ has been reported to be extremely rare. The English-language literature has six cases before 1979. During the 1980s, an additional seven cases were reported; six involved transplantation of a solid organ, and in each such case the donor was type O and the recipient was type A₁ or A₂. Recommendations regarding transfusion practice in such cases are made. An association among the transplantation of a type O organ to a type A recipient, the use of cyclosporine, and an apparent increase in the occurrence of clinically significant anti-A₁ is suggested.