For patients with rheumatoid arthritis (RA), the use of sulfasalazine is associated with a reduced risk for Pneumocystis jirovecii pneumonia (PJP), according to results published in Seminars in Arthritis and Rheumatism.
The study included data from 2005 to 2014 from a nationwide Japanese multicenter RA database. To identify PJP cases, the researchers found participants hospitalized for PJP and verified the diagnosis.
The study included 2 controls groups: 1 unmatched and the other matched for age; sex; glucocorticoid, methotrexate, tacrolimus dosage; and the use (and type) of biologic disease-modifying antirheumatic drug.
The researchers used exact and standard conditional logistic regression to estimate the odds ratios for PJP associated with sulfasalazine use and other clinical factors.
The researchers identified 60 cases of PJP along with 356 unmatched and 337 matched controls. None of the participants received sulfasalazine before the onset of PJP.
After comparing participants with PJP with unmatched controls, the researchers found that sulfasalazine use was associated with a decreased risk for PJP (adjusted odds ratio [aOR], 0.18). Comparing participants with PJP with matched controls also showed that sulfasalazine use was associated with a decreased risk for PJP (aOR, 0.08).
The researchers analyzed participants with PJP and unmatched controls who did not receive sulfasalazine and found that an increased risk for PJP was associated with lung disease (aOR, 3.88), use of glucocorticoid (aOR, 5.71), use of methotrexate (aOR, 5.25), and use of tumor necrosis factor inhibitors (aOR, 2.32).
“The prophylactic efficacy of [sulfasalazine] against PJP demonstrated by our study can have several implications for clinical practice in RA, for example, by promoting the use of [sulfasalazine] for patients with a high risk for PJP or by discouraging the administration of PJP prophylactics to patients already receiving [sulfasalazine],” the researchers wrote.
Nunokawa T, Yokogawa N, Shimada K, et al. Prophylactic effect of sulfasalazine against Pneumocystis pneumonia in patients with rheumatoid arthritis: a nested case-control study [published online June 13, 2018]. Semin Arthritis Rheum. doi:10.1016/j.semarthrit.2018.05.013