PA-450 Laboratory diagnosis of Pneumocystis jirovecii in HIV-positive infants with severe pneumonia using non-invasive samples

• Published in: BMJ global health Vol. 8; no. Suppl 10; p. A83
• Main Authors: Passanduca, Alfeu, Nkongho, Franklyn, Cassia, Uneisse, Sidat, Muhammad, Martins, Sónia, Manjate, Elias, Mavume, Celda, Seni, Amir, Chhaganlal, Kajal, Salimo, Atija, Gafur, Merunissa, Beca, Laize, Saide, Armando, Borrell, Joseph, Richardson, Shannon, Nielsen-Saines, Karin, Bramugy, Justina, Fernández-Luis, Sheila, Bassat, Quique, Bates, Matthew, Tagarro, Alfredo, Moraleda, Cinta, Rojo, Pablo, Sacarlal, Jahit, Chris Buck, W
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd 17.12.2023; BMJ Publishing Group LTD
• Subjects: Abstracts of Poster and e-Poster Presentations; Cysts; HIV; Human immunodeficiency virus; Laboratories; Medical diagnosis; Pneumonia
• ISSN: 2059-7908
• DOI: 10.1136/bmjgh-2023-EDC.203

BackgroundThe laboratory diagnosis of P. jirovecii pneumonia (PCP) is typically based on microscopic observation of cysts and trophic forms on deep respiratory specimens. In low-income countries, access to bronchoalveolar lavage is limited, particularly for children, and PCP is usually a clinical diagnosis in HIV-positive infants. The use of different laboratory tests on more easily-obtained upper respiratory and venous blood samples could enhance laboratory-confirmed PCP diagnosis.MethodsPCP-PED is an ongoing ancillary-study of the EMPIRICAL trial (#NCT03915366), supported by the EDCTP2 Program and the European Union (TMA2020CDF-3217), which recruits HIV-positive infants hospitalized with severe pneumonia from 8 hospitals in Mozambique. Nasopharyngeal aspirates are processed for direct immunofluorescence microscopy (IFM) to detect P. jirovecii cysts and for quantitative polymerase chain reaction (qPCR) targeting kex-1 gene (Genesig real-time PCR kit). Plasma samples will be used for serologic quantification of (1–3)-β-D-glucan (BG) and Human Krebs Von Den Lungen-6 (KL-6) antigens. ResultsIn interim analysis as of March 2023, 61/151 (40.4%) participants recruited have qPCR and IFM results. Median age was 4.0 [IQR, 3.1–6.3] months and 47.5% (29/61) were female. Median HIV viral load and CD4% were 6.0 logs cp/mL [IQR, 5.9 -6.9] and 13.5% [IQR, 10.0–19.6], respectively. qPCR was positive in 45.9% (28/61) and 39.3% (11/28) were on cotrimoxazole prophylaxis prior to hospitalization. The median P. jirovecii fungal load on positive samples was 13,304 copies/mL [IQR, 3,975–61,484]. Among participants with positive qPCR, 25% (7/28) were IFM positive. All participants with negative qPCR results were IFM negative; no participants with positive IFM had negative qPCR results. ConclusionPositivity rates for qPCR were higher than for IFM, suggesting superior sensitivity for P. jirovecii detection. Future analysis will focus on qPCR/IFM correlation, BG and KL-6 results, and P. jirovecii PCR fungal loads to attempt to differentiate colonization and infection.