Pneumocystis jirovecii Pneumonia Diagnostic Approach: Real-Life Experience in a Tertiary Centre

• Published in: Journal of fungi (Basel) 2023-03, Vol.9 (4), p.414
• Main Authors: Veintimilla, Cristina, Álvarez-Uría, Ana, Martín-Rabadán, Pablo, Valerio, Maricela, Machado, Marina, Padilla, Belén, Alonso, Roberto, Diez, Cristina, Muñoz, Patricia, Marín, Mercedes
• Format: Article
• Language: English
• Subjects: Brief Report; Bronchus; Connective tissue; Data collection; Diagnosis; diagnostic accuracy; Disease prevention; Hematology; HIV; Hospitals; Human immunodeficiency virus; immunocompromised host; Immunocompromised hosts; Immunofluorescence; indirect immunofluorescence; Infections; Laboratories; Lavage; Medical records; Microbiology; Mortality; Patients; Performance evaluation; Pneumocystis jirovecii; Pneumocystis jirovecii pneumonia; Pneumonia; Polymerase chain reaction; polymerase chain reaction (PCR); Ribosomal DNA; Sputum; staining; Transplants & implants; Tumors
• ISSN: 2309-608X; 2309-608X
• DOI: 10.3390/jof9040414

pneumonia (PJP) in immunocompromised patients entails high mortality and requires adequate laboratory diagnosis. We compared the performance of a real time-PCR assay against the immunofluorescence assay (IFA) in the routine of a large microbiology laboratory. Different respiratory samples from HIV and non-HIV-infected patients were included. The retrospective analysis used data from September 2015 to April 2018, which included all samples for which a test was requested. A total of 299 respiratory samples were tested (bronchoalveolar lavage fluid ( = 181), tracheal aspirate ( = 53) and sputum ( = 65)). Forty-eight (16.1%) patients fulfilled the criteria for PJP. Five positive samples (10%) had only colonization. The PCR test was found to have a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 96%, 98%, 90% and 99%, compared to 27%, 100%, 100% and 87%, for the IFA, respectively. PJ-PCR sensitivity and specificity were >80% and >90% for all tested respiratory samples. Median cycle threshold values in definite PJP cases were 30 versus 37 in colonized cases ( < 0.05). Thus, the PCR assay is a robust and reliable test for the diagnosis PJP in all respiratory sample types. Ct values of ≥36 could help to exclude PJP diagnosis.