Relationship of Chlamydia pneumoniae infection to severity of human coronary atherosclerosis.
BACKGROUND
Infection with Chlamydia pneumoniae has been postulated to play a pathogenic role in atherosclerosis. We examined the role of infection with C pneumoniae in relation to the extent of coronary atherosclerosis.


RESULTS
Coronary atherosclerosis was graded microscopically on a postmortem basis in a blinded fashion in 60 subjects as mild (n=18) or severe (n=42) atherosclerosis. Serum antibodies to C pneumoniae were measured by microimmunofluorescence test. Paraffin-embedded coronary artery specimens were examined for the presence of chlamydia by use of a genus-specific direct immunofluorescence monoclonal antibody. Frozen coronary artery specimens were examined by immunoperoxidase for the presence of C pneumoniae by use of a specific monoclonal antibody RR-402. Direct immunofluorescence was reactive in 86% of cases with severe atherosclerosis but in only 6% of cases with mild atherosclerosis (P<0.01), whereas immunoperoxidase staining was reactive in 80% and 38% of cases with severe and mild atherosclerosis, respectively (P<0. 01). Elevated IgG and IgA levels against C pneumoniae were not different in cases with severe and mild atherosclerosis (61% and 30% for severe atherosclerosis and 67% and 42% for mild atherosclerosis, respectively).


CONCLUSIONS
This study supports the hypothesis that intracellular infection with C pneumoniae may relate to the severity of atherosclerosis in some subjects. Serum antibody titers against C pneumoniae do not differentiate between severe and mild atherosclerosis.
Ericson
K
K
Unit of Forensic Medicine, Department of Surgery, Unit of Infectious Diseases and Clinical Microbiology, University of Uppsala, Uppsala, Sweden.
Saldeen
T G
TG
Lindquist
O
O
Pâhlson
C
C
Mehta
J L
JL
D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000032:analysis / Q000276:immunology; D001161:Arteriosclerosis / Q000382:microbiology* / Q000473:pathology; D002690:Chlamydia Infections / Q000150:complications*; D016993:Chlamydophila pneumoniae / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D003327:Coronary Disease / Q000382:microbiology* / Q000473:pathology; D003331:Coronary Vessels / Q000473:pathology; D003429:Cross Reactions; D005260:Female; D019085:Fluorescent Antibody Technique, Direct; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged
D000942:Antigens, Bacterial