Adult calcific aortic stenosis and Chlamydia pneumoniae: the role of Chlamydia infection in valvular calcification.

BACKGROUND Adult calcific aortic stenosis is a well-known clinical entity but its pathophysiology and cellular mechanism have yet to be defined. OBJECTIVES To determine whether there is an association between the presence and severity of adult calcific aortic stenosis and Chlamydia pneumoniae seropositivity. METHODS Forty adult patients (23 women, 17 men) were divided into three groups according to echocardiographic aortic valve area: Group A - 7 symptomatic subjects (age 67 +/- 7 years) with normal aortic valve and normal coronary angiogram, Group B - 16 patients (age 73 +/- 6) with moderate ACAS (AVA > 0.8 < or = 1.5 cm2), and Group C - 17 patients (age 76 +/- 7) with severe ACAS (AVA +/- 0.8 cm2). We tested for immunoglobulins M, G and A as retrospective evidence of C. pneumoniae infection using the micro-immunofluorescence method. Past C. pneumoniae infection was defined by IgG titer > 16 < or = 512. RESULTS No patients in group A showed positive Ig for C. pneumoniae. IgM was not detected in any of the patients with ACAS (groups B and C) while 2 of 17 patients (12%) in group C showed IgA for the pathogen. High titers of IgG were found in 14 of 33 (42%) of the patients with moderate or severe ACAS: 5 of 16 (31%) in group B and 9 of 17 (53%) in group C (P = 0.2). Both groups had the same prevalence of coronary artery disease (66%). AVA was lower in IgG-seropositive patients than in the seronegative group (0.88 +/- 0.3 cm2 vs. 1.22 +/- 0.4 cm2, respectively, P = 0.02). CONCLUSIONS Past C. pneumoniae infection may be associated with a higher prevalence and greater severity of ACAS.