Extrinsic Non-immune Hemolysis

Red blood cells (RBC) normally are destroyed and removed from the circulation after approximately 120 days. Hemolysis refers to the premature destruction of RBCs. Hemolysis can be classified into extrinsic vs intrinsic, intravascular (occurring in the circulation) vs extravascular (in the reticuloendothelial system), and immune (mediated by antibodies) vs non-immune. When the hemolysis is too severe to be compensated by the bone marrow’s overproduction, hemolytic anemia develops.