Abstract
Objective Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection that may affect patients with systemic lupus erythematosus (SLE). The objective of this project was to describe the incidence of PJP among patients with SLE.
Methods A retrospective cohort analysis of the TriNetX database was conducted. Included patients had ≥ 2 International Classification of Diseases, 9th or 10th revision, Clinical Modification (ICD-9-CM/ICD-10-CM) codes for SLE separated by at least 30 days and were new users of mycophenolate mofetil (MMF) and/or cyclophosphamide (CYC). The incidence of PJP over the first 6 months of therapy was calculated; adverse events were assessed using incidence rate ratios (IRR) and Cox proportional hazards regressions.
Results A total of 6017 patients with SLE were identified. Most were female (n = 5176, 86%) and Black or African American (n = 2138, 35.5%). Induction medications included MMF (n = 5208, 86.6%), CYC (n = 505, 8.4%), or both (n = 304, 5.1%); the most common PJP prophylaxis was trimethoprim-sulfamethoxazole (n = 1126, 18.7%). Five PJP cases were identified over 2752 person-years (PYs), one of whom received PJP prophylaxis, for an incidence rate of 1.8 cases/1000 PYs. In the adjusted analysis, patients who received prophylaxis had a higher risk of neutropenia (hazard ratio [HR] 2.5, 95% CI 1.4-4.4), leukopenia (HR 1.9, 95% CI 1.3-2.8), nephropathy (HR 1.7, 95% CI 1.4-2.1), and hyperkalemia (HR 1.4, 95% CI 0.9-2.0).
Conclusion PJP rarely affects patients with SLE undergoing therapy with MMF and/or CYC; prophylaxis against PJP is associated with adverse events. The majority of patients with SLE and PJP had structural lung disease. These data do not support universal prescribing of PJP prophylaxis for patients with SLE without lung disease.
