Clinical practice pattern of Pneumocystis pneumonia prophylaxis in systemic lupus erythematosus: a cross-sectional study from lupus registry of nationwide institutions (LUNA)

Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection in patients undergoing immunosuppressive therapy, such as glucocorticoid (GC) medication, for systemic autoimmune diseases like systemic lupus erythematosus (SLE). Despite the confirmed effectiveness of PCP prophylaxis, its clinical administration, especially in conjunction with GC dosage, remains unclear. We aimed to describe the clinical practice of PCP prophylaxis in association with SLE in Japan, evaluate the relationship between GC dosage and PCP prophylaxis, and explore the practice patterns associated with PCP prophylaxis. This cross-sectional study used data from the Lupus Registry of Nationwide Institutions in Japan from 2016 to 2021 and included patients diagnosed with SLE. Using descriptive statistics, multivariate analysis, and decision tree analysis, we examined the prevalence of PCP prophylaxis and its association with the GC dosage. Out of 1,460 patients, 21% underwent PCP prophylaxis. The frequency of prophylaxis decreased with a decrease in GC dosage. After adjusting for confounders, logistic regression revealed the odds ratio of PCP prophylaxis increased with higher prednisolone (PSL) doses: 3.7 for 5 ≤ PSL < 7.5 mg, 5.2 for 7.5 ≤ PSL < 10 mg, 9.0 for 10 ≤ PSL < 20 mg, and 43.1 for PSL ≥ 20 mg, using PSL < 5 mg as the reference. Decision tree analysis indicated that a PSL dosage of < 11 mg/day and immunosuppressant use were key determinants of PCP prophylaxis. This study provides valuable insights into PCP prophylaxis practices in patients with SLE in Japan, underscoring the importance of GC dosage and concomitant immunosuppressant use.