%0 Journal Article %T Higher incidence of persistent chronic infection of Chlamydia pneumoniae among coronary artery disease patients in India is a cause of concern %A Hem C Jha %A Harsh Vardhan %A Rishein Gupta %A Rakesh Varma %A Jagdish Prasad %A Aruna Mittal %J BMC Infectious Diseases %D 2007 %I BioMed Central %R 10.1186/1471-2334-7-48 %X Venous blood was obtained from 91 CAD patients and 46 healthy controls. Nucleic acid amplification tests viz. nested -, semi-nested ¨C and multiplex PCR were used for detection of C. pneumoniae. ELISA carried out prevalence of C. pneumoniae specific IgG and IgA antibodies.29.67% (27/91) patients were positive for C. pneumoniae using nested PCR. The sensitivity and specificity of semi-nested and multiplex PCR were 37.03%, 96.96% and 22.22%, 100% with respect to nested PCR. Positive nPCR patients were compared with presence of C. pneumoniae specific IgA, IgA+IgG and IgG antibodies. Among 27 (29.67%) nPCR C. pneumoniae positive CAD patients, 11(12%) were IgA positive, 13(14.2%) were IgA+IgG positive and only1 (1.1%) was IgG positive. A significant presence of C. pneumoniae was detected in heavy smokers, non-alcoholics and with family histories of diabetes and blood pressure group of CAD patients by nPCR.The results indicate synergistic association of C. pneumoniae infection and development of CAD with other risk factors. We also detected increased positivity for C. pneumoniae IgA than IgG in nPCR positive CAD patients. Positive nPCR findings in conjunction with persisting high C. pneumoniae specific antibody strongly suggest an ongoing infection.Coronary artery disease (CAD) is a major cause of morbidity and mortality in humans and is predicted to be the leading cause of death in the world [1]. Acquired metabolic abnormalities like hypercholesterolemia, diabetes mellitus are major risk factors associated with CAD, besides inheritance. These factors on compounding with pathogens like C. pneumoniae, Helicobacter pylori and Cytomegalovirus intensifies the magnitude of risk impending towards CAD [2,3]. Several reports have suggested a role of chronic C. pneumoniae infection in pathogenesis of CAD and other atherosclerotic syndromes [4,5]. C. pneumoniae has been established as an important pathogen that causes infections of upper and lower respiratory tract [6-8]. C. pneumon %U http://www.biomedcentral.com/1471-2334/7/48