Association between seroprevalence of anti-chlamydial antibodies and long-term cardiovascular mortality in chronic hemodialysis patients

Chlamydial infection has been suspected in the pathogenesis of ischemic heart disease. However, it remains undetermined if persistent chlamydial infection is related to cardiovascular mortality in regular hemodialysis (HD) patients. We measured Chlamydia pneumoniae (Cp) antibody seropositivity in 154 HD subjects (age 59 ± 11 years, time on HD 13 ± 7 years, male/female = 101/53), and prospectively examined an association between Cp antibody status and cardiovascular death for 56 months of follow-up. Seropositivity for Cp IgA and IgG antibodies at the entry of the study was 50.6 and 60.8%, respectively. There was no significant difference in age, time on HD, serum albumin, C-reactive protein (CRP) and interleukin-6 (IL-6) between those positive and negative for IgA antibodies. During follow-up over 56 months, 31 patients (20.1%) expired, 16 (55.2%) of them of cardiovascular causes. Serological IgA and IgG antibody positivity did not influence mortality, while multiple Cox proportional hazards analysis revealed that diabetes, ischemic changes on electrocardiogram, log-transformed CRP and intact parathyroid hormone were independent determinants of cardiovascular death. These observations suggest that serological Cp antibody status does not affect long-term cardiovascular mortality in chronic HD patients.