Chlamydia pneumoniae and Mycoplasma pneumoniae in calcified nodes of stenosed aortic valves.

OBJECTIVE: We investigated whether Chlamydia pneumoniae (CP) and Mycoplasma pneumoniae (MP) are present in aortic valve stenosis (AS).
METHODS: Immunohistochemistry was utilized to identify CP antigens, in situ hybridization to identify MP DNA, and electron microscopy was used to evaluate the following three groups: Normal – 11 normal autopsy valves; Atherosclerosis – 10 autopsy valves from patients with systemic atherosclerosis and no AS; and AS – 14 surgical specimens of AS analyzed in 3 sub-regions: AS-Preserved – peripheral, preserved regions; AS-Fibrosis – peri-calcified fibrotic tissue; and AS-Calcification – calcified nodules.
RESULTS: The positive area fraction of CP antigen median values were 0.09, 0.30, 0.18, 1.33, and 3.3 in groups Normal, Atherosclerosis, AS-Preserved, AS-Fibrosis, and AS-Calcification, respectively. CP density was significantly greater in Atherosclerosis and AS-Calcification than in Normal (P<0.05). Within the AS group, the amount of CP was greater in the Calcification and Fibrosis regions (P<0.05). MP-DNA positive area fraction (median values) were 0.12, 0.44, 0.07, 0.36, and 1.52 in groups Normal, Atherosclerosis, AS-Preserved, AS-Fibrosis, and AS-Calcification, respectively. The amount of MP-DNA was greater in AS-Calcification than in Normal (P<0.05). Within the AS group, MP-DNA was in larger quantity in the Calcification and Fibrosis regions (P<0.05).