BODY MASS INDEX, SMOKING STATUS AND RESPONSE TO RITUXIMAB IN RHEUMATOID ARTHRITIS: A REAL-LIFE STUDY.

Background: Several studies have demonstrated that obesity and smoking could have a negative influence on the response to anti-TNFα in Rheumatoid Arthritis (RA). Very few data are available about the impact of body mass index (BMI) and smoking status on other biologic agents. Objectives: To evaluate the influence of BMI and smoking status on response to Rituximab (RTX) in RA. Methods: A total of 68 RA patients treated with RTX were included in this monocentric retrospective study. BMI was calculated at the initiation of treatment. After six months of treatment, C-reactive protein level, tender and swollen joints, change of DAS28 from baseline, rates of EULAR good response and rates of remission were evaluated. Results: At baseline, the median [interquartile range] BMI was 25.04 [21.4–28.8] kg/m2. The number of patients with normal weight, overweight and obesity was 34, 22 and 12, respectively. The number of patients smokers, past smokers and never smoked was 12, 17 and 38, respectively. Baseline characteristics did not differ between the three subgroups of BMI and smoking status. After six months, the number of RA patients with DAS28 decrease ≥1.2, EULAR good response and remission was 20 (29.41%), 13 (19,11%) and 12 (17.64%), respectively. The median BMI did not differ between responders and non-responders for DAS28 decrease ≥1.2 (25.7 [22.28–28.63] vs. 24.7 [21.09–29.3], p=0.49), EULAR good response (24.22 [20.91–39.75] vs. 25.1 [21.23–28.99], p=0.96) and remission (24.08 [21.84–28.24] vs. 25.1 [21.22–29.3], p=0.81). The percentages of smokers, past smokers and never smoked did not differ between responders and non-responders for DAS28 decrease ≥1.2 (smokers 15%, past smokers 25%, never smoked 60% vs. smokers 19,15%, past smokers 25.53%, never smoked 55.32%, p=0.9), EULAR good response (smokers 15,38%, past smokers 30,77%, never smoked 53,85% vs. smokers 18,52%, past smokers 24,07%, never smoked 57,41%, p=0.87) and remission (smokers 25%, past smokers 41,67%, never smoked 33,33% vs. smokers 16.36%, past smokers 21.82%, never smoked 61.82%, p=0.18). Multivariate analysis performed on data corrected for age, sex, disease duration, concomitant treatments, and previous anti-TNFs, confirmed that BMI, body weight, and smoking status did not influence the clinical response to RTX (p>0.05 for all outcome variables considered). Conclusions: This monocentric evaluation of RA patients demonstrated that there is no influence of BMI and smoking status on response to RTX in RA. However, larger and prospective studies are needed to confirm these results that could be useful for the selection of biologics in obese and smokers RA patients. Disclosure of Interest: None declared