Autoantibodies mimicking alloantibodies: A case series unveiling the dilemmas of transfusion.

Introduction: Autoimmune hemolytic anemia is characterized by increased red cell destruction and/or decreased red cell survival due to autoantibodies directed against self-antigens on red cells. Since autoantibodies react with self and nonself red blood cells (RBCs), they tend to mask the underlying clinically significant alloantibodies and many a times mimic a specific pattern like alloantibodies.

Materials and methods: We discuss three immune hematological cases of warm autoantibodies. Antibody screening was performed by solid-phase red cell adherence (SPRCA) technique on a fully automated platform NEO Iris (Immucor Inc., USA). In case of a positive antibody screen, antibody identification was performed using SPRCA, NEO Iris (Immucor Inc., USA). Alloadsorption for adsorbing the autoantibodies was done using in-house prepared allogenic packed RBCs - R1R1, R2R2, and rr.

Results: All cases had warm autoantibody with a broad specificity against self-Rh antigens. Anti "C" and Anti "e" antibodies were identified in case 1 and autoanti "e" antibody in cases 2 and 3. Case 3 had underlying alloanti "E" along with autoanti "e" which posed a transfusion challenge.

Conclusion: Our case series highlights the importance of detecting the nature of the antibody whether it is alloantibody or autoantibody with antigen specificity. This would help in selecting appropriate antigen negative blood units for transfusion purpose.