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. 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 and carbon dioxide 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. 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. The diagnosis of primary Evans syndrome is made upon blood tests to confirm not only hemolytic anemia and immune thrombocytopenic purpura, but also a positive direct antiglobulin test (DAT) and an absence of any known underlying cause. In 27% to 50% of cases there is an associated malignancy or a predisposing autoimmune disease (e.g. systemic lupus erythematosus), it is then common to denote it as secondary Evans syndrome. Other antibodies may occur directed against neutrophils and lymphocytes, and 'immunopancytopenia' has been suggested as a term for this syndrome. Initial treatment is with glucocorticoid corticosteroids or intravenous immunoglobulin, a procedure that is also used in ITP cases.  In children, good response to a short steroid course is achieved in approximately 80 percent of cases.  Although the majority of cases initially respond well to treatment, relapses are not uncommon and immunosuppressive drugs (e.g. ciclosporin, mycophenolate mofetil, vincristine and danazol) are subsequently used, or combinations of these. The off-label use of rituximab (trade name Rituxan) has produced some good results in acute and refractory cases, although further relapse may occur within a year.  Splenectomy is effective in some cases, but relapses are not uncommon.