Chlamydia pneumoniae, strain TWAR and atherosclerosis.

Infection with Chlamydia pneumoniae, strain TWAR, has been associated with atherosclerotic cardiovascular disease in two types of investigations, seroepidemiological and morphological-molecular. A series of seroepidemiological studies from Finland and the United States have shown a statistically significant association between several types of TWAR antibody, including immune complexes, and atherosclerotic disease of the coronary and carotid arteries. The morphological-molecular studies have shown the C. pneumoniae organism in atheroma of the coronary arteries, and aorta but not in normal arteries. The presence of the organism in atheroma has been demonstrated by electron-microscopy, immunocytochemical staining with TWAR-specific monoclonal antibody and by the polymerase chain reaction for TWAR-specific DNA. The aetiological or pathogenic significance of the association of C. pneumoniae and atherosclerotic disease remains to be determined.