Immunological complications of blood transfusion: current insights and advances

Blood transfusion is integral to modern medicine but carries significant immunological risks. This review outlines key immune-mediated complications, including acute hemolytic transfusion reactions from ABO incompatibility, and febrile nonhemolytic reactions caused by cytokines or antileukocyte antibodies. Other reactions include allergic responses, anaphylaxis (notably in IgA-deficient patients), and transfusion-related acute lung injury - the leading cause of transfusion-related mortality. Delayed hemolytic reactions, alloimmunization-induced platelet refractoriness, transfusion-associated graft-versus-host disease, and post-transfusion purpura also contribute to morbidity. Transfusion-related immunomodulation may increase infection and cancer recurrence risks. Preventive measures such as leukoreduction, irradiation, extended antigen matching, and restrictive transfusion strategies are crucial. This review article emphasis the importance on the need for strict adherence to protocols, enhanced hemovigilance, and education, especially in resource-limited settings. This review article summarizes the various immunological complications of blood transfusion and the recent advances in their etiopathogenesis, prevention, mitigation, and future research direction.