Numerous genetic and environmental factors are thought to be responsible for the development of atherosclerosis, but the role of pathogens in this process remains unclear. In January 1 Circulation, Christine Espinola-Klein and colleagues at the Johannes Gutenberg University Mainz, Germany, demonstrated a strong association between viral and bacterial pathologic burden and the extent of atherosclerosis (Circulation 2002, 105:15-21).

Espinola-Klein et al. analyzed the presence and extent of peripheral artery disease in 572 patients admitted for diagnostic heart catheterization. All participants underwent coronary angiography and were classified into three groups: control (normal coronary, carotid, and leg arteries); limited disease (at least one coronary artery stenosis detected but with normal leg arteries); or, advanced atherosclerosis (patients had coronary artery disease and/or leg artery stenosis). Exposure to IgG or IgA antibodies to herpes simplex virus 1 and 2 (HSV I, II), cytomegalovirus (CMV), Epstein-Barr virus, Haemophilus influenzae,...