Auto-antibody against adenine nucleotide translocator in dilated cardiomyopathy and myocarditis--incidence and relation to cardiac function and morphology

Using an enzyme-linked immunosorbent assay, we measured anti-adenine nucleotide translocater (ANT) antibody in control subjects and in patients with dilated cardiomyopathy (DCM), myocarditis, and other heart disease. Analysis with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting, and immunoabsorption tests confirmed accurate purification of the ANT protein and correct measurement of anti-ANT auto-antibody. Anti-ANT antibody was detected in 6 of 37 cases (16%) of DCM and in 5 of 12 cases (42%) of myocarditis. This antibody was not positive in other heart diseases or in apparently healthy controls. There were no differences between anti-ANT autoantibody-positive and -negative DCM or myocarditis patients in any of the cardiac parameters examined (left ventricular ejection fraction, LVEF; left ventricular end-diastolic dimension, LVDd; and cardiothoracic ratio, CTR). Moreover, in patients who were positive for anti-ANT auto-antibody, no positive correlations were found between the parameters and anti-ANT antibody titers in either DCM or myocarditis. Although these results indicate that the detection of anti-ANT antibody was achieved at a high specificity and could have certain diagnostic value in DCM and myocarditis, there was no statistically significant relationship between the cardiac parameters (LVEF, LVDd, and CTR) and anti-ANT antibody titers in either DCM or myocarditis. Some compensatory mechanism of ventricular function may mask the effects of the anti-ANT auto-antibody or alternatively, this auto-antibody may have mimic effects on the pathogenesis and/or progression of DCM and myocarditis.