Human cytomegalovirus neutralising antibodies and increased risk of coronary artery disease in Indian population

Background Several studies have reported a conflicting association between cytomegalovirus (CMV) infection and coronary artery disease (CAD) based on the levels of total anti-CMV antibodies. However, none have estimated the levels of specific neutralising antibodies (NA) to CMV, which may be clinically more relevant. Objective To determine whether CMV—NA titres show a better association with CAD compared with total anti-CMV antibody levels. Design CMV—NA titres were measured by micro-neutralisation assay and anti-CMV IgG antibodies using ELISA in 391 consecutive CAD patients compared with the same number of controls (N=782), and 91 patients reporting recurrent cardiac events during a 4-year follow-up compared with those without a recurrent event (N=182). Levels of inflammatory markers, interleukin 6, high-sensitivity C reactive protein, fibrinogen and secretory phospholipase A2 (sPLA2), were measured by ELISA. Analysis of variance and logistic regression were used for statistical analyses. Results High CMV—NA titres showed a positive association with CAD occurrence (OR 2.24, 95% CI 1.31 to 3.85, p=0.003) and recurrent cardiac events in CAD patients (OR 4.65, 95% CI 1.21 to 17.86, p=0.025) compared with total CMV antibodies (OR 1.67, 95% CI 1.04 to 2.69, p=0.034, and 2.70, 1.04 to 7.02, p=0.040, respectively). Patients with higher quartile of CMV―NA titres and sPLA2 levels had an adjusted OR of 7.82 (95% CI 1.87 to 32.65, 0.005) for recurrent cardiac events compared with those with the lowest quartiles for both markers. Conclusion These findings suggest that high CMV―NA titres in combination with inflammatory markers improve prediction of cardiac events in the Asian Indian population.