Pneumocystis jirovecii pneumonia in intensive care units: a multicenter study by ESGCIP and EFISG
Authors: Giacobbe Daniele Roberto , Dettori Silvia , Di Pilato Vincenzo , Asperges Erika , Ball Lorenzo , Berti Enora , Blennow Ola , Bruzzone Bianca , Calvet Laure , Capra Marzani Federico , Casabella Antonio , Choudaly Sofia , Dartevel Anais , De Pascale Gennaro , Di Meco Gabriele , Fallon Melissa , Galerneau Louis-Marie , Gallego Miguel , Giacomini Mauro , González Sáez Adolfo , Hänsel Luise , Icardi Giancarlo , Koehler Philipp , Lagrou Katrien , Lahmer Tobias , Lewis White P. , Magnasco Laura , Marchese Anna , Marelli Cristina , Marín-Arriaza Mercedes , Martin-Loeches Ignacio , Mekontso-Dessap Armand , Mikulska Malgorzata , Mularoni Alessandra , Nordlander Anna , Poissy Julien , Russelli Giovanna , Signori Alessio , Tascini Carlo , Vaconsin Louis-Maxime , Vargas Joel , Vena Antonio , Wauters Joost , Pelosi Paolo , Timsit Jean-Francois , Bassetti Matteo ,   JIR-ICU investigators (collaborators), Cerchiaro Matteo , Zaccarelli Mario , Robba Chiara , Battaglini Denise , Brunetti Iole , Del Puente Filippo , Mora Sara , de la Villa Sofía , Valerio Maricela , Muñoz Patricia , Lombardi Gianmarco , Cesarano Melania , Gennenzi Veronica , Meersseman Philippe , Hermans Greet , Wilmer Alexander , Razazi Keyvan , Carteaux Guillaume , de Prost Nicolas , Cornely Oliver A. , Seidel Danila , Alastruey-Izquierdo Ana , Garcia Borrega Jorge , Bonnal Christine , de Montmollin Etienne , Dessajan Julien , Ceresini Mariaelena , Mojoli Francesco , Vola Ambra , Garnaud Cécile , Díaz Emili , Gasch Oriol , Prina Elena , Rasch Sebastian , Dibos Miriam , Haschka Stefanie ,   the Critically Ill Patients Study Group of the European Society of Clinical Microbiology and Infectious Diseases (ESGCIP), and the Fungal Infection Study Group of the European Society of Clinical Microbiology and Infectious Diseases (EFISG)
Published: August 2023

Abstract
Background
Pneumocystis jirovecii pneumonia (PJP) is an opportunistic, life-threatening disease commonly affecting immunocompromised patients. The distribution of predisposing diseases or conditions in critically ill patients admitted to intensive care unit (ICU) and subjected to diagnostic work-up for PJP has seldom been explored.

Materials and methods
The primary objective of the study was to describe the characteristics of ICU patients subjected to diagnostic workup for PJP. The secondary objectives were: (i) to assess demographic and clinical variables associated with PJP; (ii) to assess the performance of Pneumocystis PCR on respiratory specimens and serum BDG for the diagnosis of PJP; (iii) to describe 30-day and 90-day mortality in the study population.

Results
Overall, 600 patients were included in the study, of whom 115 had presumptive/proven PJP (19.2%). Only 8.8% of ICU patients subjected to diagnostic workup for PJP had HIV infection, whereas hematological malignancy, solid tumor, inflammatory diseases, and solid organ transplants were present in 23.2%, 16.2%, 15.5%, and 10.0% of tested patients, respectively. In multivariable analysis, AIDS (odds ratio [OR] 3.31; 95% confidence interval [CI] 1.13–9.64, p = 0.029), non-Hodgkin lymphoma (OR 3.71; 95% CI 1.23–11.18, p = 0.020), vasculitis (OR 5.95; 95% CI 1.07–33.22, p = 0.042), metastatic solid tumor (OR 4.31; 95% CI 1.76–10.53, p = 0.001), and bilateral ground glass on CT scan (OR 2.19; 95% CI 1.01–4.78, p = 0.048) were associated with PJP, whereas an inverse association was observed for increasing lymphocyte cell count (OR 0.64; 95% CI 0.42–1.00, p = 0.049). For the diagnosis of PJP, higher positive predictive value (PPV) was observed when both respiratory Pneumocystis PCR and serum BDG were positive compared to individual assay positivity (72% for the combination vs. 63% for PCR and 39% for BDG). Cumulative 30-day mortality and 90-day mortality in patients with presumptive/proven PJP were 52% and 67%, respectively.

Conclusion
PJP in critically ill patients admitted to ICU is nowadays most encountered in non-HIV patients. Serum BDG when used in combination with respiratory Pneumocystis PCR could help improve the certainty of PJP diagnosis.