AB0406 THE POTENT WEAPON FOR RHEUMATOID ARTHRITIS-INTERSTITIAL LUNG DISEASE : RITUXIMAB EXPERIENCES

Background: Rheumatoid arthritis (RA) is a common inflammatory disease with unknown etiology and systemic involvement (1). About 40% of RA patients have extraarticular involvement. Lung involvement is the most common extraarticular finding. The use of rituximab (RTX) in the treatment of rheumatoid arthritis- interstitial lung disease (RA-ILD) has been increasing in recent years (2). Objectives: To present our rituximab experience in patients with RA-ILD. Methods: Between April 2015 and April 2018, sixteen patients with RA-ILD who were followed up with RTX treatment in our university internal medicine-rheumatology department were included in this study. High resolution computed tomography (HRCT), carbon monoxide diffusion measurement (DLCO), pulmonary function test (PFT) and routine laboratory tests were examined. Results: The median age of the patients was 68 years (min: 52-max: 77). 4 patients (25%) were male and 12 (75%) patients were female. Four of our patients (25%) were active smokers. Non-specific interstitial pneumonia (NSIP) was seen in 10 (62.5%) patients and usual interstitial pneumonia (UIP) was seen in 6 (37.5%) patients. Before RTX, 8 patients were receiving methotrexate and 8 patients were using leflunomide. Four patients had anti-TNF (tumor necrosis factor) treatment. Median during treatment time was 6 months. Other features of the patients are summarized in Table 1. All patients had dyspnea with exertion before treatment. The Forced Vital Capacity (FVC) median was% 70 and DLCO was% 66. Although 2/16 patients received cyclophosphamide treatment, there was no clinical response and then RTX treatment was started. Protocol of treatment was every 6 months (days 0 and 15 days 1 g). After 6 months, FVC values improved with NSIP pattern (p= 0.04). There was no improvement in the UIP pattern but remained stable (Table 2). Clinically, patients’ exertional dyspnea improved. There were no serious side effects in the follow-up of the patients. Conclusion: There is no valid guideline for RA-ILD treatment. Patient-based decision-making is important in the treatment of these patients. In recent years, RTX seems to be quite effective in RA-ILD. However, long-term and extensive studies are needed in terms of maintenance treatment and possible side effects. References [1] McInnes IB, G. Schett, The pathogenesis of rheumatoid arthritis. N Engl J Med 2011; 365: 2205-19. [2] Deborah Assayag, Joyce S. Lee, Talmadge E. King, Jr., Rheumatoid Arthritis Associated Interstitial Lung Disease: A Review, MEDICINA (Buenos Aires) 2014; 72: 158-165 Key Words Rheumatoid Arthritis-Interstitial Lung Disease, Rituximab Disclosure of Interests: None declared