The present invention is directed to an aptamer comprising or consisting of the nucleic acid sequence of SEQ ID No. 1, SEQ ID No. 2, SEQ ID No. 3 and/or a nucleic acid sequence being at least 80% identical to one of SEQ ID No. 1, 2 and 3 for use in therapy and/or diagnosis of autoimmune diseases, wherein the autoimmune disease is cardiomyopathy, dilated cardiomyopathy (DCM), peripartum cardiomyopathy (PPCM), idiopathic cardiomyopathy, Chagas' cardiomyopathy, Chagas' megacolon, Chagas' megaesophagus, Chagas' neuropathy, benign prostatic hyperplasia, scleroderma, psoriasis, Raynaud syndrome, pre-eclamsia, kidney allograft rejection, myocarditis, glaucoma, hypertension, pulmonary hypertension, malignant hypertension, and/or Alzheimer's disease.