OP0173 REDUCTION OF SKIN FIBROSIS IN SYSTEMIC SCLEROSIS ON RITUXIMAB TREATMENT. LONG-TERM FOLLOW-UP

Background:A sound experience has been accumulated up to date with the use of rituximab (RTХ) for treatment of systemic sclerosis (SSc). Some studies reported improvement of skin fibrosis following treatment with RTХ, but long-term follow-ups are really few.Objectives:to evaluate the effect of RTХ on the manifestations of skin fibrosis in patients (pts) with SSc in the long-term follow-up.Methods:This prospective study included 71 pts aged 46 years (17-66) on average, 59 (83%) pts were females, mean disease duration was 5,6±4,4 years, and mean follow-up - 42 months (12-72) (mo). Diffuse SSc was established in 42 (59%) pts. All pts received glucocorticoids in low doses. 45% of pts were receiving immunosuppressants at study entry. The following parameters were evaluated: Rodnan skin score (mRSS), interdigital space(IDS) (the distance between the tips of 1 and 5 fingers at maximum extension), oral aperture (OAp) and activity index (EScSG-AI) over the periods: 12-18 mo, 24-30 mo, 36-42 mo, 48-54 mo and 60-72 mo after initiation of RTX therapy. The results are presented as: mean values, delta (Δ), median, upper and lower quartiles.Results:RTX therapy resulted in significant decrease of disease activity index, which statistically significantly correlated with decrease of mRSS - the main indicator of the severity of skin fibrosis (r=0,39;p=0,001). Changes in parameters by follow-up periods are presented in the Table 1.Table 1.Changes in clinical and instrumental parameters at RTX treatment (delta; median; lower quartile; upper quartile).Parameters12-18 mo (n=71)24-30 mo (n=55)36-42 mo (n=36)48-54 mo (n=24)60-72 mo (n=17)ΔmRSS3,32 [3.3; 0; 8]5,4 [3; 0; 10]5,1 [3,5; 0; 9]5,3 [3; 0; 10]7,3 [5; 1; 14]p=0,001p=0,001p=0,001p=0,001p=0,001ΔOAp, cm0,24 [0,1; 0; 0,5]0,26 [0,1; 0; 0,6]0,39 [0,2; 0; 0,8]0,31 [0.3; 0; 0,7]0,36 [0,2; 0; 0,8]p=0,0009p=0,0006p=0,004p=0,006p=0,009ΔActivity index (EScSG-AI)1,49 [1,5; 0; 2,5]1,64 [1,5; 0; 2,5]1,11 [1; 0; 2]2 [2; 1; 3]2,17 [2; 1,5; 2]p=0,001p=0,001p=0,0001p=0,0001p=0,0001Cumulative dose of RTX, g1,43±0,62,97±0,83,45±1,33,96±1,15,15±1,7Decreasing of mRSS statistically significantly correlated with increasing cumulative dose of RTX (r=0,29;p=0,01). Decreasing disease activity index correlated with increasing cumulative dose of RTX (r=-0,37; p=0,01). IDS improvement was documented at all assessment time periods, although statistically insignificant.Conclusion:The results of this study confirm reported positive effect of RTX on the reduction of skin fibrosis in SSc. Long-term follow-up demonstrated steadily decreasing skin fibrosis and improvement of microstomia with increasing oral aperture in parallel with a decrease of the disease activity index and increasing cumulative dose of RTX.Disclosure of Interests:None declared