Clinical Investigation of Nontuberculous Mycobacterial Lung Disease in Japanese Patients with Rheumatoid Arthritis Receiving Biologic Therapy

Objective. To review patients with rheumatoid arthritis (RA) receiving biologic therapy following a diagnosis of nontuberculous mycobacterial (NTM) lung disease and to evaluate disease deterioration according to clinical and radiological features and anti-NTM therapy. Methods. We retrospectively analyzed medical records of 11 human immunodeficiency virus-negative patients with RA (median age, 64 years) receiving biologic therapy following diagnosis of NTM lung disease. Results. NTM species included Mycobacterium avium complex in 9 patients (81.8%) and M. gordonae in 2 (18.2%). Underlying respiratory disease was present in 6 patients (54.5%), and most (81.8%) had radiographic features of nodular/bronchiectatic disease. Extent of NTM disease was 1-2 pulmonary lobes in 6 patients (54.5%), 3-4 lobes in 5 patients (45.5%), and 5-6 lobes in none. The results of radiological evaluations were unchanged or improved in 7 patients (63.6%) and worsened in 4 (36.4%). Radiological outcome was worse in patients with poor RA control despite their receiving biologic therapies for RA. Two of 3 patients receiving anti-NTM therapy as initial management for NTM improved, and 1 worsened. Three of 4 patients with worsened radiological outcome had high erythrocyte sedimentation rate (>50 mm/h). Conclusion. Radiological deterioration was not observed in the majority of patients with RA receiving biologic therapy with NTM lung disease, and radiological outcome of pulmonary NTM was favorable in some patients undergoing anti-NTM therapy. Further studies focusing on disease deterioration according to biologic therapy received during NTM followup are warranted to determine appropriate treatment of RA patients with NTM lung disease.