AB0484 EXPERIENCE WITH THE USE OF RITUXIMAB FOR THE TREATMENT OF SYSTEMIC AUTOIMMUNE DISEASES (SAD) IN A TERTIARY HOSPITAL

Background: Rituximab is a chimeric anti-CD20 monoclonal antibody used in various clinical scenarios for the treatment of SAD, especially when immunocomplexes and/or limphocyte B proliferation plays a central role. Objectives: The objective of this study was to retrospectively assess the efficacy and safety of use of rituximab in a cohort of patients with SAD in a tertiary hospital within the last 12 years. Methods: We carry out a retrospective study of 48 patients with a diagnosis of SAD in our Autoimmune and Minority Diseases Department using Google Sheets. Results: Our cohort is mostly female (48 women and 8 men). The mean age is 40.9 ±13.1 years (median 38 years). It is composed of different SAD: erythematous systemic lupus (22), granulomatosis with polyangiitis (6), dermatomyositis (6), eosinophilic granulomatosis with polyangiitis (3), rheumatoid arthritis (2), Takayasu’s arteritis (1), Kikuchi-Fujimoto disease (1), mixed connective tissue disease (i), dermatomyositis with scleroderma overlap (1), systemic sclerosis (1) foliaceus pemphigus (1), gangrenosum pyoderma, (1) polimyositis (1) and orbital pseudotumor (1). The mean time from diagnosis to rituximab was 7.7±7.1years. the efficacy of RTX in reducing disease activity after 6 month was 64.6% patients -according to the disease recommended scales-. Nevertheless, 39% maintained 1 year remission. The indications for rituximab were: persistant activity despite improvement of clasical immunosuppressive strategies (36), corticodependency (4), new relapses (3), corticoresistance (3) and toxicity (others immunosuppressant) (2). The drugs used when rituximab was used: cyclophosphamide (24), hydroxychloroquine (21), mycophenolate mofetil or mycophenolic acid (20); cyclosporine (7), immunoglobulines (7), leflunomide (4), and methotrexate (6). 5 patients did not receive any immunosuppressant. 61.3% were taking at least 2 drugs. All of them were taking glucocorticoids. In terms of security and side effects, we observed 11 (22.9%) adverse reactions related to the administration. We detect 3 infusion reactions (mild severity), 1 severe mucocutaneous reaction, 1 moderate herpes zoster, 1 fungic invasive infection and 5 severe bacterial infections (1 of them lead to rituximab suspension). We did not detect any hepatitis B virus reactivation, multifocal progressive leukoencephalopathy, cytomegalovirus infections nor herpes simplex infections. We observed 65 different haematologic adverse events: lymphopenia (34), anemia (15), neutropenia (12) and hrombocytopenia (4). No one needed specific treatment. Conclusion: Rituximab is a second line therapeutic alternative in patients with SAD in whom other treatments have failed. It is a effective drug that rescues a 65% of patients in whom other treatments have failed. Furthermore, rituximab is a safe immunosuppressant. References [1] Oon S, Huq M, Godfrey T, Nikpour M. Systematic review, and meta-analysis of steroid-sparing effect, of biologic agents in randomized, placebo-controlled phase 3 trials for systemic lupus erythematosus. Semin Arthritis Rheum. 2018 Jan 6. pii: 0049-0172(17)30579-6 [2] Tesfa D, Ajeganova S, Hagglund H, Sander B, Fadeel B, Hafstrom I, Palmblad J. Late-onset neutropenia following rituximab therapy in rheumatic diseases: association with B lymphocyte depletion and infections. Arthritis Rheum. 2011;63(8):2209 Disclosure of Interests: None declared