A new pcr‐based assay for testing bronchoalveolar lavage fluid samples from patients with suspected pneumocystis jirovecii pneumonia

Flora Marzia Liotti, Brunella Posteraro, Giulia De Angelis, Riccardo Torelli, Elena De Carolis, Domenico Speziale, Giulia Menchinelli, Teresa Spanu, Maurizio Sanguinetti

Research output: Contribution to journalArticlepeer-review

Abstract

To support the clinical laboratory diagnosis of Pneumocystis jirovecii (PJ) pneumonia (PCP), an invasive fungal infection mainly occurring in HIV‐negative patients, in‐house or commercial PJ‐specific real‐time quantitative PCR (qPCR) assays are todays’ reliable options. The performance of these assays depends on the type of PJ gene (multi‐copy mitochondrial versus single‐copy nuclear) targeted by the assay. We described the development of a PJ‐PCR assay targeting the dihydrofolate reductase (DHFR)‐encoding gene. After delineating its analytical performance, the PJ‐PCR assay was used to test bronchoalveolar lavage (BAL) fluid samples from 200 patients (only seven were HIV positive) with suspected PCP. Of 211 BAL fluid samples, 18 (8.5%) were positive and 193 (91.5%) were negative by PJ‐PCR. Of 18 PJ‐PCR‐positive samples, 11 (61.1%) tested positive and seven (38.9%) tested negative with the immunofluorescence assay (IFA). All (100%) of the 193 PJ‐PCR‐negative samples were IFA negative. Based on IFA/PCR results, patients were, respectively, classified as having (n = 18) and not having (n = 182) proven (PJ‐ PCR+/IFA+) or probable (PJ‐PCR+/IFA−) PCP. For 182 patients without PCP, alternative infectious or non‐infectious etiologies were identified. Our PJ‐PCR assay was at least equivalent to IFA, fostering studies aimed at defining a qPCR‐based standard for PCP diagnosis in the future.

Original languageEnglish
Article number681
JournalJournal of Fungi
Volume7
Issue number9
DOIs
Publication statusPublished - Aug 2021

Keywords

  • BAL fluid
  • Dihydrofolate reductase gene
  • Pneumocystis jirovecii pneumonia
  • QPCR assay

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Plant Science
  • Microbiology (medical)

Fingerprint

Dive into the research topics of 'A new pcr‐based assay for testing bronchoalveolar lavage fluid samples from patients with suspected pneumocystis jirovecii pneumonia'. Together they form a unique fingerprint.

Cite this