Non-specific immunoadsorption in patients with dilated cardiomyopathy: mechanisms and clinical effects.

An association between viral myocarditis and DCM has been hypothesized for a subset of patients with DCM. In addition to abnormalities of the cellular immune system, disturbances of humoral immunity have been described in DCM patients. A number of antibodies against various cardiac cell proteins have been identified in DCM. The functional role of cardiac autoantibodies in DCM is under debate. Circulating antibodies are extractable by immunoadsorption (IA). IA has been successfully used for treatment of a number of autoimmune diseases. IA may also represent a therapeutic option for a subset of patients with DCM. Recent open controlled pilot studies showed that removal of circulating antibodies by IA induces improvement of cardiac function in DCM. IA, furthermore, decreases myocardial inflammation. In vitro data indicate that removal of negative inotropic antibodies may represent the essential mechanism of IA in DCM. These antibodies belong to immunoglobulin G subclass 3 and may play an important role in cardiac dysfunction of DCM patients. A larger, randomized, prospective, multi-centre study will be necessary to confirm therapeutic efficacy of IA therapy in DCM.