High immunoglobulin A seropositivity for combined Chlamydia pneumoniae, Helicobacter pylori infection, and high-sensitivity C-reactive protein in coronary artery disease patients in India can serve as atherosclerotic marker.

Atherosclerosis is increasingly recognized as a chronic inflammatory disease. A variety of infectious agents (Chlamydia pneumoniae, Helicobacter pylori, and cytomegalovirus [CMV]) and inflammatory marker such as high-sensitivity C-reactive protein (hs-CRP) have been found to be associated with atherosclerosis and its consequences. There is a need to know about the type and burden of infection in coronary artery disease (CAD) patients and the level of hs-CRP in India as there is growing evidence that a variety of pathogens are participating in the development and/or acceleration of at least pre-existing atherosclerosis. In addition, there is a need to find the association between these pathogens and conventional risk factors among CAD patients in India, to possibly identify a prognostic marker. In this study 192 patients with incident or prevalent CAD attending the Cardiology Outpatient Department of Safdarjung Hospital, New Delhi, India, were enrolled. In addition, 192 age-and sex-matched controls were also included. Cases and controls differ significantly in seropositivity to C. pneumoniae immunoglobulin IgA (154 vs 76) and IgG (71 vs 48) (P < 0.001, P < 0.015), H. pylori IgA (98 vs 57) and IgG (77 vs 43) (P < 0.001, P < 0.001), CMV IgG (62 vs 38) (P = 0.01) and with hs-CRP (114 vs 60) (P < 0.001), respectively. The level of hs-CRP was higher in CAD patients with IgA seropositivity of C. pneumoniae and H. pylori (5.18 and.65 mg/l) than the IgG of these bacteria (3.73 and 3.36 mg/l), respectively. These findings support an association between specific infectious agents, namely, C. pneumoniae, H. pylori, CMV, and hs-CRP in CAD patients. Association of hs-CRP with IgA specific for C. pneumoniae and H. pylori suggests the role of chronic infection in the development of CAD and may be used as a marker to target the population.