Cardiac valves in patients with Q fever endocarditis: microbiological, molecular, and histologic studies.
The pathologic features of Q fever endocarditis, which is caused by Coxiella burnetii, were histologically evaluated in cardiac valves from 28 patients. We used quantitative image analysis to compare valvular fibrosis, calcifications, vegetations, inflammation, and vascularization due to Q fever endocarditis with that due to non-Q fever endocarditis and valvular degeneration. We also studied the presence of C. burnetii in valves by immunohistochemical analysis, culture, and polymerase chain reaction (PCR). Histologically, Q fever endocarditis was characterized by significant fibrosis and calcifications, slight inflammation and vascularization, and small or absent vegetations. Despite antibiotic treatment, non-statistically significant variations at the histologic level were observed. These pathologic features could be confused with noninfectious valvular degenerative damage. We found that the detection of C. burnetii in cardiac valves by immunohistochemical analysis, culture, and PCR decreased significantly only after 1 year of antibiotic treatment, which emphasizes the long persistence of this organism in valve tissues. Pathologic and immunohistochemical analyses may contribute to the diagnosis of Q fever endocarditis.
Lepidi
Hubert
H
Unité des Rickettsies, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6020, Institut Fédératif de Recherche 48, Faculté de Médecine, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 5, France.
Houpikian
Pierre
P
Liang
Zhongxing
Z
Raoult
Didier
D
D000328:Adult; D000368:Aged; D016997:Coxiella burnetii / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D004697:Endocarditis, Bacterial / Q000382:microbiology* / Q000473:pathology*; D005260:Female; D006350:Heart Valve Prosthesis / Q000382:microbiology; D006351:Heart Valves / Q000382:microbiology* / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011778:Q Fever / Q000382:microbiology* / Q000473:pathology*