CARDIAC AUTOIMMUNITY IN HIV-RELATED HEART-MUSCLE DISEASE

Objective-To assess the frequency of circulating cardiac specific auto antibodies in HIV positive patients with and without echocardiographic evidence of left ventricular dysfunction. Subjects-74 HIV positive pa tients including 28 with echocardiographic evidence of heart muscle di sease, 52 HIV negative people at low risk of HIV infection, and 14 HIV negative drug users who had all undergone non-invasive cardiac assess ment were studied along with a group of 200 healthy blood donors. Resu lts-Cardiac autoantibodies detected by indirect immunofluorescence (se rum dilution 1/10) were more common in the HIV positive patients (15%) , particularly the HIV heart muscle disease group (21%), than in HIV n egative controls (3.5%) (both p < 0.001). By ELISA (dilution 1/320), a bnormal anti-alpha myosin autoantibody concentrations were found more often in HIV patients with heart muscle disease (43%) than in HIV posi tive patients with normal hearts (19%) or in HIV negative controls (3% ) (p < 0.05 and p < 0.001, respectively). Anti-alpha myosin autoantibo dy concentrations were greater in HIV positive patients than in HIV ne gative controls, regardless of cardiac status ((mean SD) 0.253 (0.155) v 0.170 (0.076); p = 0.003). In particular the mean antibody concentr ation was higher in the HIV heart muscle disease patients (0.291 (0.16 0) v 0.170 (0.076); p = 0.001) than in HIV negative controls. On follo w up, six subjects with normal echocardiograms but raised autoantibody concentrations had died after a median of 298 days, three with left v entricular abnormalities at necropsy. This compared with a median surv ival of 536 days for 21 HIV positive patients with normal cardiologica l and immunological results. Conclusions-There is an increased frequen cy of circulating cardiac specific autoantibodies in HIV positive indi viduals, particularly those with heart muscle disease. The data suppor t a role for cardiac autoimmunity in the pathogenesis of HIV related h eart muscle disease, and suggest that cardiac autoantibodies may be ma rkers of the development of left ventricular dysfunction in HIV positi ve patients with normal hearts.