ISSN 2997-1036
International Journal of Hematology | Vol. 5, No. 5, May 2014 | pp. 33–40
DOI: 10.46882/2014/IJH/000053
Review Article
Title: Pathophysiology and emerging targeted therapies for the prevention of delayed hemolytic transfusion reactions in sickle cell anemia
Names of Authors: M. A. Bello¹, O. R. Eze²
Authors’ Affiliations: ¹Department of Haematology, Aminu Kano Teaching Hospital, Kano, Nigeria; ²Department of Pathology, University of Benin, Benin City, Nigeria
Abstract: Delayed hemolytic transfusion reactions represent a life-threatening immune complication in sickle cell anemia, often precipitating severe hyperhemolysis where both donor and recipient red cells undergo rapid destruction. This review explores the underlying pathophysiological mechanisms, focusing on rapid anamnestic alloantibody production against minor blood group antigens (Rh, Kell, Duffy, Kidd) and subsequent complement activation. Macrophage-mediated erythrophagocytosis, endothelial damage from free hemoglobin release, and consumption of nitric oxide contribute to a prothrombotic, hyperinflammatory state. Clinical diagnosis is challenging as it mirrors vaso-occlusive crises, causing diagnostic errors and inappropriate further transfusions. Emerging preventive strategies emphasize extensive extended red cell antigen matching and the use of prophylactic immunomodulators. Complement inhibitors like eculizumab and interleukin-6 receptor antagonists like tocilizumab represent innovative targets for cutting off the hyperhemolytic cascade. This review provides a comprehensive clinical algorithm focused on early diagnostic biomarkers, such as an unexpected drop in post-transfusion hemoglobin and elevated lactate dehydrogenase, combined with immediate immunosuppressive interventions to reduce mortality in alloyimmunized sickle cell cohorts.
Keywords: Sickle cell anemia, delayed hemolytic transfusion reaction, hyperhemolysis, alloimmunization, complement inhibitors
Manuscript Timeline: Received: February 11, 2014; Revised: March 22, 2014; Accepted: April 10, 2014; Published: May 19, 2014