Comparison of individuals with and without specific IgA antibodies to Chlamydia pneumoniae: respiratory morbidity and the metabolic syndrome.

Study Objectives: To determine whether a correlation exists between markers for persistent Chlamydia pneumoniae infection, respiratory morbidity, and the metabolic syndrome.

Design: Case-control study. A group of individuals with serologic markers (specific IgA > or = 1/128) suggestive of persistent C pneumoniae infection were compared with a group of control subjects without IgA antibodies (< 1/32).