呼吸器・呼吸器内科

Background: Pneumocystis Jirovecii Pneumonia (PCP) remains a significant cause of pneumonia in non-HIV immunosuppressed patients. There are no established guidelines on PCP prophylaxis in patients with rheumatic diseases. This study aimed to identify the risk factors associated with PCP infection with the aim of guiding prophylaxis in patients with rheumatic disease.

Method: Patients with rheumatic diseases diagnosed with PCP in a single tertiary care center were included as cases. Control patients were selected from patients followed up by the Division of Rheumatology. The ratio of case to control was 1:3. Demographic characteristics, clinical and laboratory findings of patients, systemic involvement of rheumatic disease and recent treatment history were recorded.

Results: Seventeen patients were diagnosed with PCP during the study period. A total of 51 patients completed clinical data were included in the control group. Rheumatoid arthritis (33.8%) was the most common disease, followed by systemic lupus erythematosus. None of the patients received PCP prophylaxis. The recent treatment of all patients consisted of methylprednisolone, disease modifying anti-rheumatic drugs, other immunosuppressive drugs, and biological agents (55.9%, 35.3%, 19.1%, and 11.8% of the patients, respectively). None of the PCP patients had active arthritis, but 52.9% of the control group had. Regarding treatment, PCP patients more frequently used glucocorticoids at a dose of 16 mg or higher (58.8% vs. 11.8%, p<0.001). Similarly, PCP developed more frequently in patients who had received pulse treatment in the preceding six months (47.1% vs. 2%, p<0.001). None of the patients receiving biological agents developed PCP, all patient used biologic agent were in the control group (p=0.056)

Conclusion: PCP develops more frequently in patients with rheumatic diseases receiving moderate-to-high doses of glucocorticoids and/or who have received pulse immunosuppressive therapy in the last six months. These patients should be strongly considered for PCP prophylaxis.