The progression of lower limb atherosclerosis is associated with IgA-antibodies against Chlamydia pneumoniae

Objective: to study the influence of serologically diagnosed chronic infect ion with Chlamydia pneumoniae on the progression of lower limb atherosclero sis in a group of disposed men. Material and methods: the highest systolic brachial and lowest systolic ank le blood pressures were followed for an average of 2.7 years in 129 men age d 65-73 years with conservatively treated small abdominal aortic aneurysms. Blood samples were taken to measure low-density lipoprotein and IgA and Ig G titres of antibodies against C. pneumoniae by a microimmunofluorescence t est. Results: the prevalences of seropositivity varied from 43 to 83% depending on the definition. The ankle-brachial blood pressure index of the IgA-seron egative men decreases by 11%, while it decreased by 4.8% among IgA-seronega tive men (p<0.05). The significant difference persisted in a multiple-regre ssion analysis adjusting for age, smoking, initial systolic ankle BP, and i nitial brachial systolic or diastolic BP, but disappeared after adjusting f or the level of low-density lipoprotein. Conclusions: C. pneumoniae infection is associated with the progression of atherosclerosis.