Clinical Characteristics and Outcomes of Pneumocystis Pneumonia in Solid Organ Transplant Recipients

BACKGROUND: Solid organ transplant (SOT) recipients are at risk for Pneumocystis jirovecii pneumonia (PCP), yet how their clinical phenotype and outcomes compare with other immunocompromised patients without HIV remains poorly defined. METHODS: We conducted a multicenter retrospective cohort study of adults with proven or probable PCP from 2017 to 2025, including 95 SOT recipients and 588 non-SOT, non-HIV immunocompromised patients. The primary outcome was 90-day mortality, secondary outcomes included new renal failure requiring dialysis, and 30-day mortality. Outcomes were analyzed using inverse probability weighting (IPW) with winsorization to adjust for baseline differences. RESULTS: In unadjusted analysis, SOT recipients had lower 90-day mortality (hazard ratio [HR]: 0.62, 95% CI 0.39-0.97, p = 0.037). After IPW with winsorization of extreme weights, SOT status remained associated with lower 90-day mortality (HR: 0.32, 95% CI 0.13-0.76, p = 0.009), and 30-day mortality (HR: 0.35, 95% CI: 0.14-0.92, p = 0.034). SOT recipients had higher odds of renal failure requiring dialysis in unadjusted analysis (OR: 3.49, 95% CI 1.94-6.14, p < 0.001), which persisted after IPW adjustment (OR: 1.62, 95% CI: 1.04-2.51, p = 0.032). CONCLUSIONS: Despite higher rates of renal failure requiring dialysis, SOT recipients with PCP experienced significantly improved short- and intermediate-term survival compared with other non-HIV immunocompromised patients, underscoring the need for further investigation into transplant-associated contributors to PCP outcomes.