Persistence of Chlamydia pneumoniae in degenerative aortic valve stenosis indicated by heat shock protein 60 homologues.
OBJECTIVE
Based on the concept of chronic persistent infections with Chlamydia pneumoniae among variable stressors for aortic valve degeneration, the study aim was to assess the presence of chlamydial heat shock protein (cHSP) 60 and its human homologue (hHSP60) in diseased valvular tissue.


METHODS
Surgical specimens of high-grade stenosed, native (n = 33) and bioprosthetic (n = 10) aortic valves were examined immunohistochemically for the localization of cHSP60, hHSP60 and macrophages (CD68), supplemented by polymerase chain reaction (PCR) and electron microscopy to prove microbial presence.


RESULTS
Degenerated valves showed specific immunostaining of cHSP60 in 27 cases (65%), of hHSP60 in 26 (63%), and of CD68 in 36 (84%). Both HSP60 homologues were predominantly detected in valvular fibrosa, consistently co-localized with macrophages and, quantitatively, showed a strong correlation (r = 0.81, p < 0.001). Presence of C. pneumoniae was demonstrated by PCR in a subset of 11 of 18 valves (61%). Microbial persistence was confirmed by ultrastructural analysis. Degenerated prosthetic valves revealed markedly higher macrophage infiltration and cHSP60 signaling compared with degenerated native valves (each p < 0.05).


CONCLUSIONS
Beyond detection of C. pneumoniae, the present data on co-localization and valvular predilection sites (fibrosa) of both HSP60 homologues indicate the presence of chronic persistent C. pneumoniae infection as well as regional stressor effects, and suggest their involvement in native and prosthetic valve degeneration.
Skowasch
Dirk
D
Heart Center University of Bonn, Bonn, Germany.
Yeghiazaryan
Kristina
K
Schrempf
Stephanie
S
Golubnitschaja
Olga
O
Welsch
Ulrich
U
Preusse
Claus J
CJ
Likungu
James A
JA
Welz
Armin
A
Lüderitz
Berndt
B
Bauriedel
Gerhard
G
D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000382:microbiology; D001024:Aortic Valve Stenosis / Q000453:epidemiology / Q000382:microbiology*; D018834:Chaperonin 60 / Q000302:isolation & purification / Q000378:metabolism*; D023521:Chlamydophila Infections / Q000150:complications; D016993:Chlamydophila pneumoniae; D015897:Comorbidity; D003324:Coronary Artery Disease / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D005656:Fungal Proteins / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction
D018834:Chaperonin 60; D005656:Fungal Proteins