A rare case of a clinically significant anti-M alloantibody in a heart transplant recipient

Abstract

Introduction: Anti-M antibodies are usually inactive at physiologic temperatures (37 °C). Rarely, these antibodies have been reported to react at physiologic temperatures, resulting in clinically significant hemolytic transfusion reactions or hemolytic disease of the fetus and newborn.

Patient and methods: We describe a case of an acute hemolytic transfusion reaction due to an anti-M alloantibody reacting at physiologic temperatures in a critically ill patient.

Results: Proper identification and management of anti-M antibody-mediated acute hemolysis rapidly improved and stabilized her hemoglobin.

Conclusion: Differentiation between anti-M antibody-mediated acute hemolysis and its differential diagnoses is of critical importance to guide therapeutic decisions in these rare clinical scenarios.

Keywords: Alloantibody; Anti-M antibody; Autoantibody; Hemolytic transfusion reaction.