ABO-Incompatible Living Donor Liver Transplant From a Blood Type A2 Donor to a Type B Recipient: A Note of Caution.

Standardization of immunomodulation protocols has enabled ABO-incompatible liver transplants with outcomes similar to those of ABO-compatible liver transplants. Patients with the A2 blood group are unique because they have a diminished expression of the A antigen. Despite rare immune complications, this phenomenon of diminished expression has led to treatment of type A2 donors according to the regimen for type O blood group donors in ABO-incompatible liver transplants. Additionally, the requirement for pretransplant recipient immunomodulation is consi dered minimal when considering these donors. The transplant of a type A2 donor kidney to a type B recipient is well recognized; however, for liver donation the A2-to-B transplant is rare. Here, we present a case of 48-year-old male patient with blood group type B who underwent ABO-incompatible liver transplant of a right lobe liver graft from a type A2 donor. Postoperatively, despite adequate immunosuppression and initiation of thera - peutic plasma exchange, the patient developed severe and refractory antibody-mediated rejection that ultimately abated with a splenectomy. This report highlights the low but tangible risk of antibody-mediated rejection in ABO-incompatible liver transp lants from type A2 donors and emphasizes the importance of serial monitoring of anti-A isohemag glutinin titers and posttransplant splenectomy to ensure that liver grafts with antibody-mediated rejection can be rescued.