Rheumatoid arthritis with nontuberculous mycobacterial pulmonary disease: a retrospective, single-centre cohort study

Nontuberculous mycobacterial pulmonary disease (NTM-PD) is a rare but important comorbidity of rheumatoid arthritis (RA). Our objective was to investigate the association between NTM-PD and RA, especially regarding the immunosuppressive treatment of RA such as biological disease-modifying antirheumatic drugs (bDMARDs). We conducted a retrospective, single-centre cohort study. All RA patients regularly followed up at our rheumatology division in December 2012 were included in the study, and followed for 5 years. At baseline, 26 of 1639 RA patients had NTM-PD. During the observation period, 14 were newly diagnosed with NTM-PD. For new diagnosis of NTM-PD, bDMARD use at baseline was not a significant risk factor. Among the 40 patients with NTM-PD, 16 were treated with a total of 27 bDMARDs after NTM-PD diagnosis. They did not present with a greater exacerbation of NTM-PD than those not treated with bDMARDs (25 vs. 17%, p = .52). A total of 55 patients died, but nobody died of NTM-PD. NTM-PD was not associated with worse mortality in multivariate analysis (hazard ratio, 2.0; 95% CI, 0.6-6.4; p = .26). Biological DMARD was not associated with worse prognosis of NTM-PD. Careful use of bDMARDs could be tolerated in RA patients with NTM-PD.