THU0345 EFFECT OF THE LONG-TERM RITUXIMAB TREATMENT ON B-LYMPHOCYTES AND ANTINUCLEAR AUTOANTIBODY LEVEL IN PATIENTS WITH SYSTEMIC SCLEROSIS

Background: Anti-B-cell therapy is seen as a promising therapeutic option for systemic sclerosis (SSc). The study of antinuclear antibody levels during treatment with rituximab (RTX) in patients (pts) with SSc could have theoretical and practical interest. Objectives: To assess the changes in ANA, anti-topoisomerase-1 (Scl-70) levels and B-lymphocytes (B-lymph) count during RTX therapy during prospective observation. Methods: This prospective study included 88 pts with SSc, 83% of them had interstitial lung disease and 75% had positive Scl-70 autoantibody. The mean age was 47 yrs (17-71), female-73 pts (83%), the diffuse cutaneous subset of the disease had 50 pts (57%). The mean disease duration was 5,9±4,8 yrs. The mean follow-up period was 27 months (12-42). The cumulative mean dose of RTX was 2,9±1,1grams. All patients received prednisolone at a dose of 11,7±4,4 mg, immunosuppressants received 42% of them. Patients were divided into groups depending on the duration of the disease: group 1 (n=33) - up to 3 yrs, group 2 (n=25) - from 3 to 6 yrs, group 3 (n=30) - more than 6 years (6-18yrs). The results are presented in the form of mean values, median, upper and lower quartiles. Results: Parallel to clinical improvement in most patients (96%) we found positive changes in many parameters at the end of the study compared to the baseline. The Rodnan skin score decreased from 11,21±9,33 to 6,19±4,74 (p Conclusion: In our study a clinical improvement was shown in most pts at the long-term complex therapy, including RTM. We found a significant decrease in the absolute number of B-lymph, as well as decrease of ANA and Scl-70 levels. Initially pts with a short duration of the disease had a higher level of B-lymph and in these pts depletion was more pronounced, compared to those with a longer duration of the disease. However, the level of Scl-70 and ANA decreased both to those who started RTX therapy at an early stage of the disease ( Disclosure of Interests: None declared