Objective Atherosclerosis is an autoimmune condition and the underlying cause of coronary artery disease (CAD). Circulating antibodies to self-antigens can have a pathogenic or protective function in atherosclerosis. The objective of the study was to understand the association of autoantibody levels with CAD and its correlation with circulating immune cells.
Methods We assessed antigen concentration and antibodies to apolipoprotein B (ApoB) and heat shock protein (HSP)60 by ELISA in 252 acute coronary syndromes (ACS), 112 patients with stable angina (SA) and 203 healthy controls from Indian population. T cells in peripheral blood mononuclear cells (PBMC) were enumerated by flow cytometry. Cytokine concentrations were measured by multiplex assay.
Results IgG and IgM antibodies to ApoB and HSP60 proteins were significantly lower in patients with ACS while only IgG levels to ApoB were lower in patients with SA, compared with control. Subjects in the highest tertile of antibodies showed significantly lower OR for ACS (IgG 0.52, 95% CI 0.31 to 0.88, p=0.02 and IgM 0.58, 95% CI 0.34 to 0.98, p=0.04), ApoB100 (IgG 0.52, 95% CI 0.31 to 0.88, p=0.02 and IgM 0.58, 95% CI 0.34 to 0.99, p=0.04) and HSP60, respectively. Interestingly, T helper 17 (TH17) cells showed an inverse relationship with ApoB and HSP60 IgG antibodies (r2=−0.17, p<0.001 and r2=−0.20, p<0.001, respectively), while interleukin 17 concentrations were negatively correlated with IgM antibodies to the proteins
Conclusion This study shows that higher antibodies to ApoB and HSP60 proteins are less often associated with ACS and that these antibodies are inversely associated with inflammatory Th17 cells.
- coronary artery disease; autoimmune response; antibodies
- heat shock proteins
- apolipoprotein B
- T helper cells
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Dr Vijay V Kakkar died on 5 November 2016.
Contributors The study was designed by SKV and LAM. SKV (cardiologist) authenticated the sample identification. MR was the clinical coordinator and helped in the collection of demographic and clinical data. All experiments were performed by TP. The first draft was written by TP, reviewed and corrected by LAM and SKV. All the authors approved the final draft.
Funding The study is supported by the Indian Council of Medical Research (ICMR), Government of India (5/4/1-4/11-NCD-II), and research grants from Tata Social Welfare Trust, India (TSWT/IG/SNB/JP/Sdm).
Competing interests None declared.
Patient consent Obtained.
Ethics approval Institutional ethics committees of Thrombosis Research Institute and Narayana Hrudayalaya Hospital.
Provenance and peer review Not commissioned; externally peer reviewed.
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