Interstitial lung disease constitutes a significant treatment burden in patients with rheumatoid arthritis

Introduction This study investigated the impact of interstitial lung disease (ILD), a prevalent complication of rheumatoid arthritis (RA), on the achievement of treatment goals in clinical practice under the treat-to-target (T2T) strategy. Methods This retrospective observational study included patients with newly diagnosed RA who underwent chest computed tomography (CT) within 1 year of RA onset between 2016 and 2022. The presence of ILD was assessed using chest CT imaging. Treatment goals were evaluated at 6, 12, and 24 months after treatment started. The goals were low disease activity (CDAI < 10), low inflammation (CRP < 0.5 mg/dL), and glucocorticoid (GC)-free status. Then, univariate and multivariate analyses were performed to identify factors impacting goal achievement. Results and discussion Of the 254 patients, 57 (22.4%) had RA-ILD. Patients with ILD were older, had higher Anti-citrullinated protein antibodies (ACPA) and rheumatoid factor (RF) positivity, used GCs more frequently, and had lower methotrexate usage. At all-time points, patients with ILD were significantly less likely to achieve treatment goals than those without ILD (21.2% vs. 37.8% at 6 months, p < 0.05; 25.0% vs. 48.9% at 12 months, p < 0.05; and 21.3% vs. 56.8% at 24 months, p < 0.01). Multivariate analysis showed that ILD, high baseline CRP, and GC use at the start of treatment were independently and negatively associated with treatment goals, with the adverse impact of ILD increasing over time. In conclusion, RA-ILD acts as a substantial barrier to the effective implementation of T2T strategies in RA.