Chlamydia pneumoniae antibodies and high lipoprotein(a) levels do not predict ischemic cerebral infarctions results from a nested case-control study in northern Sweden

Background and Purpose-An association between high lipoprotein(a) I[Lp(a)] levels and positive Chlamydia pneumoniae IgG titers in coronary artery dise ase has been described. The possibility of predicting ischemic stroke by me asurements of plasma Lp(a) and C pneumoniae antibodies was investigated. Methods-This incident case-control study included 101 case subjects (cases) who had suffered ischemic cerebral infarctions and 201 matched control sub jects (controls). The study population was nested within the Vasterbotten I ntervention Program or the WHO MONICA project. Plasma samples were measured for C pneumoniae-specific IgG and IgA antibodies and Lp(a). Results-A significantly higher mean Lp(a) level was found ire female cases than in female controls. However, plasma Lp(a) was unable to predict ischem ic cerebral infarctions in either women or men. The proportion of individua ls with positive C pneumoniae-specific IgG or IgA titers did not differ bet ween cases and controls. Antibody titers were unable to predict a future st roke. The proportion of individuals with a positive C pneumoniae IgG titer in combination with a high Lp(a) level did not differ significantly between cases and controls. Conclusions-These data suggest that there is no association between baselin e plasma Lp(a) levels, presence of C pneumoniae antibodies, and future isch emic cerebral infarctions, Furthermore, no evidence of an interactive effec t between high Lp(a) levels and C pneumoniae Ige titers was found. However, selection bias and a recent C pneumoniae epidemic may have influenced the results.