Retrospective cohort links imaging features to outcomes in non-HIV Pneumocystis pneumonia

Pleural effusion and worsening chest radiographs during the first week of treatment were associated with adverse short-term outcomes in a retrospective cohort study of 198 HIV-negative immunocompromised patients with Pneumocystis jirovecii pneumonia. Patients with pleural effusion had higher odds of death within 30 days, death within 14 days and the need for invasive mechanical ventilation, while radiographic worsening among 94 patients with serial images was linked to both mortality and ventilation. The investigators described the imaging findings as exploratory, citing wide confidence intervals, limited outcome events, incomplete characterization of pleural effusion and the need for prospective confirmation.

The study took place at a single tertiary medical center. Eligible patients had proven or probable PJP under EORTC/MSGERC criteria, were HIV-negative and were immunocompromised. Their mean age was 59 years, and 60% had a hematological malignancy. A blinded radiologist assessed chest radiographs and computed tomography studies available at diagnosis, along with chest radiographs obtained 7–10 days later when repeat imaging was available. The primary outcome was 30-day mortality, while secondary outcomes included 14-day mortality and the need for invasive mechanical ventilation. The multivariable logistic regression analyses were exploratory and restricted to four prespecified covariates.

Clinical measurements also showed associations with mortality. A high Charlson Comorbidity Index was associated with 30-day death, with an adjusted odds ratio of 2.68 and a 95% confidence interval of 1.01–8.49. Elevated lactate dehydrogenase, or LDH, was likewise associated with 30-day mortality, with an adjusted odds ratio of 1.82 and a 95% confidence interval of 1.10–3.11. These findings were consistent with previous studies, according to the researchers. Because the cohort was observational, the analyses identified associations rather than demonstrating that comorbidity burden or elevated LDH caused death. The retrospective, single-center design also restricts how broadly the results can be generalized.

Pleural effusion was recorded as present or absent but not further characterized by laterality, extent or cause. In the exploratory adjusted models, it was associated with 30-day mortality at an odds ratio of 5.87, with a 95% confidence interval of 2.42–16.57; 14-day mortality at an odds ratio of 8.79, with a 95% confidence interval of 2.90–38.41; and mechanical ventilation at an odds ratio of 5.88, with a 95% confidence interval of 2.31–17.61. The wide intervals reflected the limited number of outcome events. The study therefore identified a possible association between pleural effusion and adverse outcomes, but the absence of anatomical and etiological detail and the imprecision of the estimates preclude treating it as a definitive prognostic marker.

Radiographic evolution could be evaluated in the 94 patients who underwent serial radiography. Patients whose images worsened had higher observed rates of death within 14 days, 40% compared with 15% among those without worsening, with a p-value of 0.008. Their 30-day mortality was 48% compared with 22%, with a p-value of 0.014, and the proportion requiring mechanical ventilation was 53% compared with 24%, with a p-value of 0.009. In a sensitivity analysis using a 14-day landmark, radiographic worsening was not associated with subsequent mortality. Thus, the serial-imaging results supported an association during the early course of PJP, but the independent prognostic contribution of radiographic worsening remains uncertain and requires prospective confirmation. Overall, the cohort identified pleural effusion and early radiographic worsening as potential markers of poor short-term outcomes in this HIV-negative population, while also demonstrating the need for larger, prospective studies with more detailed imaging assessment.

Subject of Research: Chest imaging features associated with short-term outcomes in non-HIV Pneumocystis jirovecii pneumonia

Article Title: Radiographic features associated with adverse outcomes in Pneumocystis jirovecii pneumonia in HIV-negative immunocompromised patients: a retrospective cohort study

Article References: Kaplunsky, J., Even-Dar, R., Massarwa, M., Shorbaji, N., Neuberger, A., & Ershaid, N. (2026). Radiographic features associated with adverse outcomes in Pneumocystis jirovecii pneumonia in HIV-negative immunocompromised patients: a retrospective cohort study. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14682-9

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14682-9

Keywords: Pneumocystis jirovecii, Pneumocystis pneumonia, pleural effusion, chest radiography, computed tomography, immunocompromised patients, HIV-negative patients, mortality, mechanical ventilation, retrospective cohort, Radiographic, features