Diagnosis of invasive aspergillosis using bronchoalveolar lavage in haematology patients: influence of bronchoalveolar lavage human DNA content on real-time PCR performance.
In order to improve invasive pulmonary aspergillosis (IPA) diagnosis, a real-time polymerase chain reaction (PCR) assay detecting Aspergillus spp. was developed. Its detection limit reached 2-20 conidia. The retrospective evaluation on 64 bronchoalveolar lavage (BAL) fluids from 57 patients at risk for IPA, including 20 probable and five proven IPA patients, revealed a 88% or 38% sensitivity in direct examination (DE)/culture-positive or culture-negative BAL, respectively, whereas galactomannan (GM) sensitivity reached 88% or 58%, respectively. Influence on the Aspergillus-PCR yield of BAL fluid volume, cellular count and DNA content (evaluated by human beta-globin quantification) was assessed. Significantly higher beta-globin levels were detected in Aspergillus PCR-positive (median 5,112 pg/microl) than negative (median 1,332 pg/microl) BAL fluids, suggesting that the beta-globin level could reflect BAL yields and DNA extraction. Using beta-globin for the interpretation of fungal PCR could improve the negative predictive value of this test.
Fréalle
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EA 3609, Département de Parasitologie-Mycologie, Faculté de Médecine, Pôle de Microbiologie, CHRU de Lille, Université de Lille 2, Laboratoire d'Ecologie du Parasitisme, Institut Pasteur de Lille, Lille, France. e-frealle@chru-lille.fr
Decrucq
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Botterel
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Bouchindhomme
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Camus
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Dei-Cas
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Costa
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JM
Yakoub-Agha
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I
Bretagne
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Delhaes
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