Chlamydia pneumoniae antibodies in various subtypes of ischemic stroke in Indian patients.

Background: As infections occur more frequently in developing countries, we carried out this prospective case-control study, to establish the association, if any, between C. pneumoniae antibodies and ischemic stroke particularly in relation to its subtypes.

Design: Antibodies (IgG and IgA) to C. pneumoniae in serum were measured by microimmunofluorescence test in 200 consecutive ischemic stroke patients and 200 age and sex matched controls.

Results: Seventy two out of 200 ischemic stroke patients (36%) had positive C. pneumoniae antibodies (IgG or IgA), compared to 35 out of 200 controls (17.5%) (p<0.0001). IgG antibody was positive in 64/200 (32%) ischemic stroke patients, compared to 34/200(17%) controls (p<0.0001) and IgA was positive in 20/200(10%) ischemic stroke patients compared to 1/200(0.5%) controls (p<0.0001). Logistic regression analysis showed statistically significant association between C. pneumoniae antibody positivity and ischemic stroke, thereby establishing it as an independent risk factor. Prevalence of C. pneumoniae antibodies was significantly higher in all stroke subtypes (except the stroke of undetermined etiology) compared to controls.

Conclusion: Significant and independent association was found between C. pneumoniae antibodies and ischemic stroke in this sample of south Indian population. The association was found in all ischemic stroke subtypes, except stroke of undetermined etiology.