title: Impact of HIV Infection Status on Interpretation of Quantitative PCR for Detection of Pneumocystis jirovecii.
abstract: Quantitative PCR (qPCR) is now a key diagnostic tool for Pneumocystis pneumonia. However, cutoffs to distinguish between infected and colonized patients according to their HIV status have not yet been determined. According to clinical, radiological, and biological data, we retrospectively classified bronchoalveolar lavage (BAL) samples subjected to qPCR over a 3-year period into four categories, i.e., definite PCP, probable PCP, Pneumocystis colonization, and no infection. Fungal burden was then analyzed according to the HIV status of the patients. Among 1,212 episodes of pneumonia screened in immunocompromised patients, 52 and 27 HIV-positive patients were diagnosed with a definite and probable PCP, whereas 4 and 22 HIV-negative patients had definite and probable PCP, respectively. Among patients with definite or a probable PCP, HIV-negative patients had a significantly lower burden than HIV-positive patients (P < 10(-4)). In both groups, the median fungal burden was significantly higher in patients with definite PCP than in colonized patients. A single cutoff at 1.5 × 10(4) copies/ml allowed to differentiate colonized and infected HIV-positive patients with 100% sensitivity and specificity. In HIV-negative patients, cutoff values of 2.87 × 10(4) and 3.39 × 10(3) copies/ml resulted in 100% specificity and sensitivity, respectively. Using cutoffs determined for the whole population would have led us to set aside the diagnosis of PCP in 9 HIV-negative patients with definite or probable PCP. qPCR appeared to be the most sensitive test to detect Pneumocystis in BAL samples. However, because of lower inocula in HIV-negative patients, different cutoffs must be used according to the HIV status to differentiate between colonized and infected patients.
authors.affiliation: Assistance Publique-Hôpitaux de Paris, Hôpital St Antoine, Service de Parasitologie-Mycologie, Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Louis
authors.affiliation: Assistance Publique-Hôpitaux de Paris, Hôpital St Antoine, Service de Parasitologie-Mycologie, Paris, France Inserm, U1135, Centre Immunologie et Maladies Infectieuses, Paris, France CNRS, ERL 8255, Centre Immunologie et Maladies Infectieuses, Paris, France Sorbonne Universités, UPMC Univ Paris 06, CR7, Centre Immunologie et Maladies Infectieuses, Paris, France.
authors.forename: J
authors.initials: J
authors.lastname: Guitard
authors.affiliation: Assistance Publique-Hôpitaux de Paris, Hôpital St Antoine, Laboratoire Commun de Biologie et Génétique Moléculaires, Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Jodar
authors.affiliation: Assistance Publique-Hôpitaux de Paris, Hôpital Cochin, Service de Parasitologie-Mycologie, Paris, France.
authors.forename: T
authors.initials: T
authors.lastname: Ancelle
authors.affiliation: Assistance Publique-Hôpitaux de Paris, Hôpital St Antoine, Service de Parasitologie-Mycologie, Paris, France.
authors.forename: D
authors.initials: D
authors.lastname: Magne
authors.affiliation: Assistance Publique-Hôpitaux de Paris, Hôpital St Antoine, Laboratoire Commun de Biologie et Génétique Moléculaires, Paris, France.
authors.forename: O
authors.initials: O
authors.lastname: Lascols
authors.affiliation: Assistance Publique-Hôpitaux de Paris, Hôpital St Antoine, Service de Parasitologie-Mycologie, Paris, France Inserm, U1135, Centre Immunologie et Maladies Infectieuses, Paris, France CNRS, ERL 8255, Centre Immunologie et Maladies Infectieuses, Paris, France Sorbonne Universités, UPMC Univ Paris 06, CR7, Centre Immunologie et Maladies Infectieuses, Paris, France christophe.hennequin@sat.aphp.fr.
authors.forename: C
authors.initials: C
authors.lastname: Hennequin
mesh_terms: D000328:Adult; D000368:Aged; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D002353:Carrier State / Q000175:diagnosis* / Q000382:microbiology; D015169:Colony Count, Microbial / Q000379:methods*; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D045363:Pneumocystis carinii / Q000302:isolation & purification*; D011020:Pneumonia, Pneumocystis / Q000175:diagnosis* / Q000382:microbiology; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012189:Retrospective Studies