Long-term deterioration of interstitial lung disease in patients with rheumatoid arthritis treated with abatacept

Objective: To examine the deterioration of interstitial lung disease (ILD) in patients with rheumatoid arthritis (RA) treated with abatacept over the long-term. Methods: We examined 131 patients with RA who had been treated with abatacept for more than 1 year. All patients underwent high-resolution computed tomographic (HRCT) scanning of the chest before administration of abatacept, and we examined deterioration of ILD over a follow-up period after administration of abatacept was initiated. Results: Eleven patients (8.4%) showed deterioration of ILD over a mean follow-up period of 47.8 months. The factors related to ILD deterioration were use of methotrexate (MTX) [odds ratio 12.75, 95% confidence interval (CI) 1.09-148.77], and change in Krebs von-den Lungen-6 (odds ratio 1.00, 95% CI 1.00-1.01), according to multivariate logistic regression analysis. Conclusion: MTX in patients with RA treated with abatacept was a risk factor for deterioration of ILD. Discontinuation of MTX should be considered one of treatment reduction to prevent the deterioration of ILD.