Chlamydia pneumoniae infection and accelerated development of coronary artery disease in patients with chronic renal failure

Aims: This study examined the relationship between Chlamydia pneumoniae (C. pneumoniae) infection and the accelerated development of coronary artery d isease (CAD) in patients with chronic renal failure (CRF). Methods: Two-hun dred and fourteen patients undergoing coronary angiography, including 67 co ntrols and 147 patients with CAD (97 without CRF and 50 with CRF), were enr olled in this study. Anti-C. pneumoniae specific IgG and IgA antibodies wer e measured using an enzyme-linked immunosorbent assay (ELISA). Results: Cor onary artery disease (expressed as CAD score) was more severe in patients w ith than without CRF(14.9 +/-6.0 vs. 11.3 +/-6.0, p<0.01). Seropositive rat es of IgG and IgA antibodies against C. pneumoniae were higher in all CAD p atients than in the controls (76.2% vs. 44.8%, p<0.001 for IgG; 59.9% vs. 4 0.3%, p<0.01 for IgA). In both CAD subgroups, IgG seropositive rates were s imilarly elevated (82.0% and 73.2% vs. 44.8% for control, p<0.001, respecti vely), whereas those of IgA were significantly elevated only in CAD with CR F (68.0% vs. 55.7% for control, p<0.01). The mean antibody index of IgG was elevated in all CAD patients compared with the controls (1.9<plus/minus>1. 0 vs. 1.3 +/-0.9, p<0.0001), but that of IgA was not (1.5<plus/minus>1.0 vs . 1.2 +/-0.9). Levels of I-G were elevated in all patients with CAD compare d with the control (2.4 +/-1.1 and 1.8 +/-1.0 vs. 1.3 +/-0.9, p<0.001 and p <0.001, respectively), whereas those of IgA were elevated only in CAD with CRF (1.8 +/-1.1 vs. 1.2 +/-0.9, p<0.05). Stepwise logistic regression analy sis revealed that the elevated IgG antibody index was an independent risk f actor for CAD regardless of CRF (odds ratios 1.9, 1.8, and 2.3), whereas th e IgA index was a risk factor only in CAD with CRF (odds ratio 1.7). Conclu sions: Chlamydia pneumoniae infection may be related to the accelerated CAD in patients with CRF, which was specifically suggested by an elevated IgA level. In other words, the prevalence of active C. pneumoniae infection is higher in patients with CAD and CRF than that in those with CAD without CRF .