The Association between the Response to Rituximab with Sociodemographic Data and Disease Characteristics Among a Sample of Iraqi Patients with Rheumatoid Arthritis

Background: Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease. Rituximab (RTX), a monoclonal antibody with anti-CD20 action, is now used as a treatment. Even with proper RTX use, some patients showed variations in response. Objective: To assess the association of different sociodemographic data and disease characteristics with RTX responsiveness in RA patients. Methods: A cross-sectional study was conducted in the Specialized Center of Rheumatology at Baghdad Teaching Hospital in Baghdad, Iraq. The study included 90 RA patients who received a 1000mg RTX intravenous infusion for at least six months. The collected sociodemographic data included age, gender, smoking status, body mass index (BMI), disease characteristics such as co-morbidities, and the use of previous biological agents. The activity of RA was assessed by the 28-joint Disease Activity Score (DAS28) and Clinical Disease Activity Index (CDAI). Results: Upon measuring the DAS28, the enrolled patients were divided into RTX responders (50 patients) and RTX non-responders (40 patients). Patients with a family history of RA were significantly higher in the RTX responders (21% versus 2% in the non-responders group). The responders had a significantly longer RA duration (p=0.030).The mean of CDAI and DAS28 were significantly higher in patients with no family history of RA than in those with a family history of RA. Conclusions: Disease duration, family history, and the use of previous biological agents could be considered as possible predictors of response to RTX, thereby saving time and treatment costs.