AB0420 The same treatment response of mono- and combined-mtx treatment in dmards-naÏve turkish patients with seropositive rheumatoid arthritis and the importance of pulmonary toxicity

Background Methotrexate (MTX) is the anchor drug for the treatment of rheumatoid arthritis (RA). There are important guidelines suggesting mono-MTX treatment at first for pharmacologic treatment of RA (1,2). We thought that these recommendations should be evaluated in different geographic regions and ethnic groups because of genetic factors. Objectives Therefore, we aimed to compare the efficacy and adverse effect profile of mono-MTX and combined-MTX treatments in patients with DMARDs-naive Turkish patients with seropositive RA. Methods Hundred patients with seropositive RA (mean age: 47.4±12.0 years, 63 females and 37 males) were included. Patients were excluded the past history of using for synthetic or biologic DMARDs or moderate-high dose steroid (u003e10mg/day), viral hepatitis, transaminase elevations, and other contra-indications for MTX. Then they were divided as mono-MTX (n=57) and combined-MTX (n=43) groups. Results There was no difference between groups in age (p=0.34), sex (p=0.104), age of onset (p=0.10), MTX-weekly dose (p=0.228), the score of DAS28 (p=0.783), RF level (p=0.473), and CCP level (p=0.592) at the beginning. Patients of combined-DMARDs group used higher dose of prednisolone than patients of mono-MTX group (p=0.011). The change of DAS28 scores was not different between groups. CRP levels of combined-MTX group were higher than mono-MTX group both beginning and at 6th month. The frequencies of adverse events were not different between groups. GI adverse events are the first line in both groups (28% vs.16.3%). The frequencies of dose decrease (7% vs. 14%) or stop (7% vs. 4.7%) for MTX were also not different between groups (p=0.288, p=0.257). The frequencies of other adverse effects were less than 5%. MTX dose decrease or stop have been moderately correlated with pulmonary involvement (r=0.4, p=0.02). Conclusions Both mono-MTX and combined-MTX treatment had similar efficacy and safety profile in Turkish patients with seropositive RA as reported in studies of other countries suggesting no any advantage of combined MTX compared to mono-MTX (3). The frequency of MTX-stopping in our study was similar to this systematic review (9%). As a conclusion, MTX should also be the first choice of the treatment of RA in our country. Pulmonary adverse events should not be ignored. References Singh JA, Saag KG, Bridges SL J, et al. 2015 American College of Rheumatology Guideline for the Treatment of Rheumatoid Arthritis. Arthritis Rheumatol. 2016;68(1):1–26. Smolen JS, Landewe R, Breedveld FC, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2013 update. Ann Rheum Dis. 2014;73(3):492–509. Katchamart W, Trudeau J, Phumethum V, et al. Methotrexate monotherapy versus methotrexate combination therapy with non-biologic disease modifying anti-theumatic drugs for RA. Cochrane Database od Systematic Reviews 2010;Issue 4.Art.No.:CD008495. Disclosure of Interest None declared