Autoimmune hemolytic anemia (AIHA) is caused by hemolysis induced by the reaction of autoantibodies with red blood cells (RBCs). Events that lead to AIHA include extravascular hemolysis caused by phagocytosis of erythrocyte-bound IgG in the spleen (hemolytic mechanism), activation of polyclonal B cells, reactions induced by molecular mimicry of exogenous antigens, breakdown of immune tolerance, and abnormal cytokine expression (autoimmune mechanism).
Evans syndrome is diagnosed by the simultaneous presence of AIHA, which is detected using a direct antiglobulin test (DAT), and immune (idiopathic) thrombocytopenic purpura (ITP) in the absence of an underlying etiology. This syndrome is characterized by hemolytic anemia, thrombocytopenia, and the production of either antibodies, or complement, or both that attack RBCs and platelets.
Toru Shizumaâ Autoimmune Hemolytic Anemia Following Influenza Virus Infection or
Administration of Influenza Vaccineâ
Last date updated on July, 2014