Clinical features and prognostic predictors in patients with rheumatic diseases complicated by Pneumocystis pneumonia.

Objectives: To investigate the clinical outcomes and risk factors of mortality in patients with rheumatic diseases complicated by Pneumocystis pneumonia (PCP).

Methods: Between November 2015 and April 2021, patients with rheumatic diseases with PCP in a tertiary referral hospital were retrospectively enrolled. The diagnosis of PCP requires the fulfillment of clinical, radiographic, and microbiological criteria. Factors associated with in-hospital, 30-day, and 90-day mortality were evaluated.

Results: A total of 128 patients with rheumatic diseases who had a positive quantitative polymerase chain reaction assay for Pneumocystis jirovecii were screened, and 72 patients were included in the final analysis. The median (interquartile range [IQR]) pneumonia severity index (PSI) was 101.5 (77.0-132.0). The median (IQR) adjunctive corticosteroid dosage was 0.6 (0.4-0.9) mg/kg/day prednisolone equivalent. The receiver operating characteristic curve analysis showed that the optimal cutoff point of median adjunctive corticosteroid dosage was 0.6 mg/kg/day to predict in-hospital, 30-day, and 90-day mortality. In the multivariable logistic regression analysis, median adjunctive corticosteroid dosage ≥0.6 mg/kg/day and PSI >90 were independent factors of in-hospital, 30-day, and 90-day mortality.

Conclusion: A median adjunctive corticosteroid dosage of ≥0.6 mg/kg/day might be associated with mortality in patients with rheumatic diseases complicated by PCP.