Effect of sulfasalazine use on the presence of Pneumocystis organisms in the lung among patients with rheumatoid arthritis: A test-negative design case-control study with PCR tests

• Published in: Modern rheumatology 2019-05, Vol.29 (3), p.436-440
• Main Authors: Nunokawa, Takahiro, Yokogawa, Naoto, Shimada, Kota, Sugii, Shoji
• Format: Article
• Language: English
• Subjects: Adult; Aged; Antirheumatic Agents - pharmacology; Antirheumatic Agents - therapeutic use; Arthritis, Rheumatoid - drug therapy; Case-control study; Female; Humans; Lung - microbiology; Male; Middle Aged; Pneumocystis carinii - drug effects; Pneumocystis carinii - pathogenicity; Pneumocystis pneumonia; Pneumonia, Pneumocystis - epidemiology; prophylaxis; rheumatoid arthritis; sulfasalazine; Sulfasalazine - pharmacology; Sulfasalazine - therapeutic use
• ISSN: 1439-7595; 1439-7609
• DOI: 10.1080/14397595.2018.1465647

Objective: To evaluate the effect of sulfasalazine (SSZ) on the presence of Pneumocystis jirovecii (P. jirovecii) in the lungs of rheumatoid arthritis (RA) patients. Methods: We retrospectively studied episodes of suspected P. jirovecii pneumonia (PJP) which were examined for P. jirovecii with polymerase chain reaction (PCR). We employed a test negative design case-control study; the cases were episodes of suspected PJP that were positive for PCR, and the controls were episodes of suspected PJP that were negative for PCR. The odds ratio for the positive PCR result associated with SSZ use was estimated by Firth's logistic regression. Results: Between 2003 and 2017, 36 cases and 83 controls were identified. While none of the cases received SSZ before the episode, 18 of the controls received the drug. In the primary analysis involving all the episodes, SSZ use was negatively associated with PCR positivity (adjusted odds ratio, 0.087; confidence interval,