Evans syndrome

Evans syndrome is an autoimmune disease in which an individual's immune system attacks their own red blood cells and platelets, the syndrome can include immune neutropenia. These immune cytopenias may occur simultaneously or sequentially. Its overall phenotype resembles a combination of autoimmune hemolytic anemia and immune thrombocytopenic purpura. Autoimmune hemolytic anemia is a condition in which the red blood cells that normally carry oxygen are destroyed by an autoimmune process. Immune thrombocytopenic purpura is a condition in which platelets are destroyed by an autoimmune process. Platelets are a component of blood that contribute to the formation of blood clots in the body to prevent bleeding. The syndrome was first described in 1951 by R. S. Evans and colleagues. The symptoms of Evans syndrome vary between patients depending on which blood cells are affected. If red blood cells are attacked, symptoms may include weakness and fatigue, paleness or jaundice, shortness of breath, lightheadedness, and/or a fast heartbeat. If platelets are attacked, symptoms may include increased bruising, prolonged nosebleeds, increased bleeding from minor cuts, and/or Petechiae. In the less common instance that white blood cells are attacked, symptoms may include increased proneness to infection, fevers, and/or mouth sores. It has been variously reported that between 7.8% and 23% of patients who have autoimmune hemolytic anemia, will also have thrombocytopenia and thus Evans syndrome. The two cytopenias may occur together or sequentially. Although Evans syndrome seems to be a disorder of immune regulation, the exact pathophysiology is unknown, but a gradual loss of self-tolerance is postulated. Autoantibodies targeted at different antigenic determinants on red cells and platelets are assumed to cause isolated episodes of hemolytic anemia and thrombocytopenia, respectively. Diagnosis of Evans syndrome is separated into primary and secondary presentation. There is no single test to confirm a diagnosis of either form of Evans syndrome.