SERUM ANTINUCLEAR ANTIBODIES IN CORONARY ARTERY DISEASE

Abstract

Background- Inappropriate inflammation is a key mechanism in the development of atherosclerosis. Antibodies against components of the atherosclerotic lesion, in particular, oxidized low density lipoprotein, have been described. The prevalence of systemic autoimmune reactions as characterized by the presence of high titers of serum antinuclear antibodies have also been reported in patients with advanced coronary atherosclerosis. This study was performed to determine whether or not a systemic autoimmune response, characterized by the presence of high titers of antinuclear antibodies, is associated with the presence of coronary atherosclerosis. Methods- In this case-control study, serum was prepared from 55 subjects (aged 59±9.3) with at least 50% stenoses of three main coronary arteries (3VD subjects), and 41 subjects (aged 52.6±7.6)with no evidence of coronary atherosclerosis (NCA subjects) as determined by coronary angiography. The presence of antinuclear antibodies (ANA) was determined by HEp-2 cell as the substrate using DAKO kits (FITC conjugated rabbit anti-human antibodies) for IgA, IgG, IgM and IgK. The titers of 1/40 or more were considered positive. Observers who graded the test results were unaware of the angiograms.<br />Results- Ninety-six subjects (mean age 55.8±9.3 years, 40-76 years old) entered the study. Demographic and clinical variables were matched among case and control groups except for age and gender. 3VD groups were older (59±9.3 vs. 52.6±7.6, p<0.001) and most of them were male (57.3% vs. 42.7%, p<0.02). Among the NCA group, 11 of 41 subjects (27%) were ANA positive and among 3VD patients, 15 of 55 subjects (26.2%) were ANA positive (p=0.978).<br />Conclusion- The presence of ANA, commonly associated with autoimmune diseases, is not substantially more prevalent among subjects with severe coronary atherosclerosis than those with normal coronary arteries. There is no evidence of autoimmune and systemic markers in both groups. This association does not merit further assessment as a potentially useful indicator of increased risk of coronary heart disease.