Background Interstitial lung disease (ILD) is the most common manifestation of rheumatoid lung disease (RA-ILD). The prevalence of RA-ILD is somewhere between 10 and 50 percent, depending on the study. In analogy with Systemic Sclerosis associated ILD (SSc-ILD), high resolution computed tomography (HRCT) has become the gold standard for diagnosis of RA-ILD. Literature data describe a strong correlation between HRCT pattern of ILD and histopathological subtypes. Moreover, different systems for evaluating SSc-ILD on HRCT and several scoring methods have been proposed for RA-ILD. Because of the uncertainty of the effect of traditional DMARDs and biologic agents on the development and course of ILD in patients with RA, careful pre-treatment assessment and subsequent monitoring are required. We present the results of the follow-up to 1 year of a cohort of patients treated with DMARDs and maintained in the therapeutic target (DAS28 low disease activity or remission).
Objectives To evaluate the change in respiratory function and ILD HRTC score in a cohort of patients treated to target.
Methods 24 RA patients in DMARD monotherapy and low dose steroid (dose of prednisone <7.5 mg/die), followed by treat-to-target strategy and kept in DAS28 low disease activity or remission, were enrolled. All patients were evaluated with pulmonary function tests (global spirometry, DLCO and hemogasanalysis) and HRCT at time of the enrollment and after 1 year of follow-up. All HRCT examinations were performed according to standard protocol. The parenchymal abnormalities on HRCT were coded and scored in all the images by two independent readers, blinded with respect to the results, according to Warrick et al. The severity and extent of disease were then calculated as total HRCT score (range from 0 to 30).
Results 19 of 24 patients were in MTX monotherapy (mean MTX weekly dose: 12.5 mg) and 5 were in Leflunomide monotherapy. Mean RA disease duration was 4.8 yr (±0.6 SD). 20 of 24 patients presented HRCT signs of ILD with Warrick score ≥1. At time 0 mean HRTC score was 8 (±5 SD), mean extension score was 4 (±2 SD) and mean severity score was 4 (±3 SD). At time 1 yr mean HRTC score was 8,04 (±3,73 SD), mean extension score was 3,37 (±1,86 SD) and mean severity score was 4,66 (±2,11 SD) (p=NS). Mean DLCO was 74 (±21 SD) at time 0 and 66 (±18 SD) at the end of follow-up (p=NS). We found no statistically significant modification in total lung capacity (TLC) and Tiffenau index (FEV1/FVC) during follow-up.
Conclusions As previously reported, we found high prevalence of RA-ILD. In our treated-to-target RA cohort in DMARD monotherapy, we have not detected neither functional nor radiological progression during 1 year follow-up. In our cohort the DMARD therapy has not worsened the ILD. We can speculate that control the activity of joint disease with a strategy to treat target may contribute to prevent lung disease progression.
Disclosure of Interest None declared