Hyperhomocyst(e)inemia and Chlamydiapneumoniae IgG seropositivity in patients with coronary artery disease

Abstract

Elevated levels of homocyst(e)ine and infection by Chlamydia pneumoniae have been hypothesized individually to play a role in coronary artery disease (CAD), but the mechanisms are unclear. Data on a possible association are not available. We investigated the correlation between IgG antibody titers against C. pneumoniae and fasting plasma homocyst(e)ine in 234 consecutive male patients with CAD. Chlamydial antibodies to a recombinant genus-specific lipopolysaccharide (LPS) were measured with ELISA. Total homocyst(e)ine (tHcy) concentrations were measured by high-performance liquid chromatography (HPLC). Thirty-seven subjects were classified hyperhomocyst(e)inemic (fasting homocyst(e)ine>14 μmol/l, group A), and 197 subjects were below cut-off (tHcy<14 μmol/l, group B). Prevalence of IgG seropositivity against C. pneumoniae was significantly higher in group A (68%) as compared to group B (39%, P=0.002). Antibody titers were also significantly higher in hyperhomocyst(e)inemic subjects than in cases with low homocyst(e)ine levels ( P=0.002). Overall titers correlated significantly with tHcy levels ( r 2=0.222, P=0.001). Hyperhomocyst(e)inemia was associated with arterial hypertension ( P=0.003), intake of lipid lowering drugs ( P=0.022) and quite not with low folate concentration ( P=0.052) . No association was seen for IgG seropositivity or homocyst(e)ine and age, body mass index, smoking, diabetes, vitamin B 6 and B 12, cholesterol and triglycerides. These data indicate an association between elevated plasma homocyst(e)ine concentrations and chlamydial IgG antibody titers in patients with CAD.