ABO-INCOMPATIBLE HEART-TRANSPLANTATION - A SPECIAL CASE FOR THE A(2) DONOR

Limited clinical experience concerning heart transplantation across AB O blood group barriers suggests a high incidence of hyperacute rejecti on and poor patient outcome. Reported is a case of the short-term surv ival of an ABO-mismatched cardiac graft without evident adverse immuno logic effects. A 41-year-old man with blood type O underwent heart tra nsplantation receiving a blood type A2 donor organ. Cyclosporine-based immunosuppression was augmented with daily plasmapheresis and OKT3 th erapy. Circulating anti-A antibodies were reduced quickly and held to a very low level with this regimen. The patient remained hemodynamical ly stable until retransplantation 4 days later. The explanted heart sh owed no evidence of cellular infiltrate or antibody deposition. Long-t erm success with the use of type A2 organs in type O recipients has be en shown in select series with other types of solid organ transplants. Although this patient underwent retransplantation early, the lack of rejection phenomena gives evidence that the relatively low antigenicit y of the A2 subtype may allow planned heart transplantation across thi s blood group barrier, either as a bridge or on a permanent basis.