Genetic Testing to Resolve the Source of Hemolytic Antibody in Solid Organ Transplantation

Abstract

Introduction Antibody-mediated hemolysis arising in the face of solid organ transplant can be devastating. Some degree of passenger lymphocyte syndrome is said to occur in up to 10% of ABO mismatched renal transplants, 40% of ABO mismatched liver transplants, and 70% of ABO mismatched heart-lung transplants, a reflection of the number of memory B-cells transplanted with the organ. Passenger lymphocyte syndrome is less common with minor antigens but can still be severe. Materials and Methods A series of patients developed immune hemolytic anemia after solid organ transplantation. Conventional serologic testing was performed using tube and solid-phase testing. Molecular testing was performed using gene-chip array. Results In patients receiving a minor antigen mismatched organ transplant and multiple allogenic red cell transfusions, serologic methods proved insufficient to resolve the source of minor blood group antibodies that arose in the aftermath of transplant. Genetic testing was able to clearly resolve donor and recipient types. Conclusions Passenger lymphocyte syndrome after mismatched organ transplantation is not rare. The mixtures of organ donor, recipient, and other transfused RBCs profoundly limit the usefulness of serologic testing. Genetic assignment of minor blood types to donor and recipient can guide therapy and inform prognosis.