Characteristics and prognosis factors of Pneumocystis jirovecii pneumonia according to underlying disease: a retrospective multicentre study.

BACKGROUND: Pneumocystis jirovecii pneumonia (PcP) remains associated with high rates of mortality and the impact of immunocompromising underlying disease on the clinical presentation, severity and mortality of PcP has not been adequately evaluated.

RESEARCH QUESTION: Does the underlying disease and immunosuppression causing Pneumocystis jirovecii pneumonia (PcP) impact the outcome and clinical presentation of the disease?

STUDY DESIGN AND METHODS: In this multicentre retrospective observational study, conducted from January 2011 to December 2021, all consecutive patients admitted with a proven or probable diagnosis of PcP according to The European Organization for Research and Treatment of Cancer (EORTC) consensus definitions were included to assess the epidemiology and impact of underlying immunosuppressive diseases on overall and 90-day mortality.

RESULTS: Overall, 481 patients were included in the study, 180 (37.4%) were defined as proven PcP and 301 (62.6%) as probable PcP. Patients with immune-mediated inflammatory diseases (IMID) or solid tumors had a statistically poorer prognosis than other patients with PcP at D90. In multivariate analysis, among HIV-negative population, solid tumor underlying disease (OR 5.47, 2.16-14.1; p<0.001), IMID (OR 2.19, 1.05-4.60; p=0.037), long term corticosteroid exposure (OR 2.07, 1.03-4.31; p=0.045), cysts in sputum/BAL smears (OR 1.92, 1.02-3.62; p=0.043), and SOFA score at admission (OR 1.58, 1.39-1.82; p<0.001) were independently associated with 90-day mortality. Prior corticotherapy was the only immunosuppressant associated with 90-day mortality (OR 1.67, 1.03-2.71; p=0.035), especially for a prednisone daily dose ≥ 10 mg (OR 1.80, 1.14-2.85; p=0.010).

INTERPRETATION: Among HIV-negative patients, long term corticosteroid prior to PcP diagnosis was independently associated with increased 90-day mortality, specifically in IMID patients. These results highlight both the needs for PcP prophylaxis in IMID patients as well as to early consider PcP curative treatment in severe pneumonia among IMID patients.