The present invention relates to a method for diagnosis of a disease selected from the group of diabetes, vasculitis, collagenosis, an inflammatory rheumatic disease and arteriosclerosis wherein, presence or absence of an anti-AT1-receptor antibody is determined in a sample from a patient to be diagnosed and wherein, the presence of an anti-AT1-receptor antibody is indicative of the disease. The invention further relates to the use of an inhibitor of an anti-AT1-receptor antibody or an inhibitor of an AT1-receptor for the production of a medicament as well as plasmapheresis of blood for the removal of anti-AT1-receptor antibodies.
