Successful Orthotopic Heart Transplantation in a Patient with Anti-U Antibody

Abstract Objective The U (universal) antigen is part of the MNS blood group present at a frequency of nearly 100% in Caucasians and 98% of African Americans. The anti-U antibody is clinically significant and has been reported to cause hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. Methods Routine forward and backward typing, direct antiglobulin testing, and an antibody screen were performed. In addition, red blood cell phenotype and adsorption studies were also performed. Results The patient was found to have a rare anti-U antibody, rendering all available inventory in our hospital incompatible for transfusion. Conclusion This is the first reported case of solid organ transplantation in a patient with an anti-U alloantibody. Appropriate pretransplant evaluation and coordination between the clinical team and transfusion medicine service must be optimized to procure rare packed red blood cell units in a timely manner.