title: Characteristics and clinical relevance of the quantitative touch-down major surface glycoprotein polymerase chain reaction in the diagnosis of Pneumocystis pneumonia.
abstract: The evaluation of quantitative polymerase chain reaction (PCR) characteristics can increase the accuracy of the laboratory diagnosis of Pneumocystis pneumonia (PCP). Between July 2008 and September 2009, 66 non-sequential prospective bronchoalveolar lavage (BAL) samples, obtained from five HIV-infected and 49 non HIV-infected patients were investigated, using a quantitative-touch-down-PCR to determine the number of copies of major surface glycoprotein (MSG) genes of Pneumocystis jirovecii (q-TD-MSG-PCR). PCP was confirmed by microscopic observation of Pneumocystis, radio-clinical and therapeutic data in 18/54 patients. For PCP, the cut-off was 54.3 MSG copies per ml of BAL fluid. The PCR was positive in these same 18 cases and it was the only positive assay in two cases and the earliest diagnosis test in one case of PCP relapse. The likelihood positive ratio, sensitivity and specificity of the q-TD-MSG-PCR were 44, 100% and 97.7%, respectively. The Predictive Negative Value was 100% and the Predictive Positive Value of 95.5%, the intra- and inter-assay variability values were 2.7% (at more than 30 MSG copies) and 11.7% (at 10,000 MSG copies), respectively. Quantitative PCR can help diagnose PCP even in cases of low Pneumocystis load and might decrease morbidity in association with very early specific treatments.
authors.affiliation: Laboratory of Parasitology and Mycology, Grenoble University Hospital, Joseph Fourier University (Grenoble 1), France. BChumpitazi@chu-grenoble.fr
authors.forename: Bernabé F F
authors.initials: BF
authors.lastname: Chumpitazi
authors.forename: Pierre
authors.initials: P
authors.lastname: Flori
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Kern
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Brenier-Pinchart
authors.forename: Virginie
authors.initials: V
authors.lastname: Hincky-Vitrat
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Brion
authors.forename: Anne
authors.initials: A
authors.lastname: Thiebaut-Bertrand
authors.forename: Clémence
authors.initials: C
authors.lastname: Minet
authors.forename: Daniele
authors.initials: D
authors.lastname: Maubon
authors.forename: Hervé
authors.initials: H
authors.lastname: Pelloux
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D002648:Child; D005260:Female; D015658:HIV Infections / Q000150:complications; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009172:Mycology / Q000379:methods*; D045363:Pneumocystis carinii / Q000235:genetics / Q000302:isolation & purification*; D011020:Pneumonia, Pneumocystis / Q000175:diagnosis* / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D008562:Membrane Glycoproteins