Antibodies against heart muscle and nuclear constituents in cardiomyopathy

Abstract

The prevalence of HAB and ANA was determined in eight patients with idiopathic hypertrophic subaortic stenosis (IHSS) and 35 patients with cardiomyopathy (CM). HAB was found in 88 per cent of patients with IHSS and in 17 per cent of those with CM. Antinuclear antibody was found in 63 per cent of patients with IHSS and 43 per cent of those with CM. Aging alone was not responsible for the high prevalence of ANA in the former group, but may be partly so in the latter. There was an increased tendency for women in both groups to have ANA. An increased serum concentration of IgM was also observed in women in the IHSS and CM groups. Serum concentrations of IgG and IgA, precipitating antibodies to nuclear constituents, rheumatoid factors, and a positive serologic test for syphilis were not increased in patients with idiopathic cardiomyopathy. Positivity to HAB and ANA did not remain constant and was not present frequently in sera in follow-up studies of these patients. No instance of a negative test becoming positive was recorded for either HAB or ANA. The high prevalence of ANA in patients with IHSS and CM and an increased prevalence of HAB in patients with IHSS may suggest that an autoimmune disturbance is operative in these forms of cardiomyopathy.