Association between seropositivity to Chlamydia pneumoniae and acute ischaemic stroke.

Recent studies suggest an association between Chlamydia pneumoniae infection with atherosclerosis, including cerebrovascular disease. We investigated the prevalence of Chlamydial seropositivity in patients with acute ischaemic stroke syndrome compared with age- and sex-matched control subjects. Specific antibodies (IgA) to C. pneumoniae were measured by microimmunofluorescence in both the clinical group (n=91) and the control group (n=112). Forty patients (43.9%) and 34 controls (30.3%) had positive IgA titres (P < 0.05). The pooled data from this and previous series yielded 45% of seropositivity in cerebrovascular patients vs. 19% in control subjects (P < 0.001). In conclusion, we suggest an association between chronic infection by C. pneumoniae and acute ischaemic stroke.