IS ALPHA-METHYLDOPA-TYPE AUTOIMMUNE HEMOLYTIC-ANEMIA MEDIATED BY INTERFERON-GAMMA

Drug-related autoimmune hemolytic anemia appearing with warm-reacting antibodies can be classified according to the offending substances. On e of the subtypes can be induced by alpha-methyldopa. However, the pat hophysiology of the underlying mechanism is not yet known. In parallel , patients with Parkinson's disease and other extrapyramidal disorders , who are under administration of dopaminergic drugs, often present wi th abnormal findings with respect to immune parameters. In order to re veal further mechanisms within the immune response, the capability of patients under dopaminergic medication to release cytokines after a st imulatory signal was examined. Therefore, 18 patients who were treated with the dopamine analogue lisuride were compared with an aged-matche d control group of 21 healthy volunteers. After stimulation with phyto hemagglutinin (PHA), mitogen-induced concentrations of interferon-gamm a were significantly higher in the patients treated with lisuride than in the control group. Interferon-gamma leads to an upregulation of MH C class-I and especially class-II molecules on antigen-presenting cell s and to an induction of antibody production in B cells. This conditio n can result in the induction of an autoimmune process. It might be su pposed that alpha-methyldopa-type autoimmune hemolytic anemia is media ted by elevated levels of interferon-gamma produced in T cells after a stimulatory signal.