[Autoantibodies against heartmuscle sarcolemma in sera of patients with an idiopathic cardiomyopathy (author's transl)].

68 patients with clinical and hemodynamical diagnosis of idiopathic cardiomyopathy (CM) were analysed for antibody in their sera using an immunofluorescence sandwich technique after titration of the sera in tissue sections. 60 of these patients had antibodies against heart muscle sarcolemma with titers up to 1:64. Out of these, the antibodies in 9 sera could be absorbed with group A streptococci. The antibodies reacted in no case with striated or smooth muscle sarcolemma. The 25 patients with an obstructive type of CM showed the highest titers and 12 of them, in addition, had antinuclear factors in their sera. These findings suggested an auto-allergic etiology for most cases of idiopathic CM.