Immunocomb Chlamydia bivalent assay to study Chlamydia species-specific antibodies in patients with coronary heart disease.

BACKGROUND & OBJECTIVE Serological evidences suggested an association between Chlamydia pneumoniae infection and coronary heart disease (CHD). Efficacy of available serological tests for detection of C. pneumoniae antibody has been debated. The present study was carried-out to assess the efficacy of Immunocomb Chlamydia bivalent IgG assay vis-à-vis micro immunofluorescence (MIF) test in detecting C. pneumoniae and C. trachomatis--specific antibodies in patients with CHD. METHODS Serum samples collected from clinically confirmed cases of CHD (n=114) were subjected to Immunocomb Chlamydia bivalent assay and the standard MIF test. Antibodies specific to C. pneumoniae and C. trachomatis were detected quantitatively. RESULTS Though Immunocomb Chlamydia bivalent test yielded 73.7 per cent positivity for C. pneumoniae- specific IgG antibody (compared to 50.8% by MIF), the specificity of Immunocomb was found only 32.14 per cent. Positive and negative predictive values of Immunocomb assay were 54.8 and 60.0 per cent respectively. INTERPRETATION & CONCLUSION The findings of the present study indicated that though Immunocomb assay was inferior to MIF, it can be used as a method for presumptive serology due to its rapidity and ease of performance. Wherever possible, one or more additional tests should also be performed to increase the specificity of such studies.