Evaluation of the effect of rituximab on fatigue in rheumatoid arthritis using the Chalder Fatigue Scale

Objective. Fatigue is a frequent extra-articular manifestation of rheumatoid arthritis (RA), with a reported prevalence ranging from 40% to 90%. It affects physical, emotional, and cognitive aspects of daily life and significantly impairs quality of life. Although biologic therapies may improve fatigue, the specific effect of rituximab on this symptom remains insufficiently documented. This study aimed to evaluate the effect of rituximab on fatigue at baseline (M0), 4 months (M4), and 6 months (M6) using the Chalder Fatigue Scale (CFS). Methods. This prospective, observational, single-center study included patients fulfilling the 2010 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for RA and treated with rituximab. Rituximab was administered as two intravenous infusions (500 mg or 1000 mg) on day 0 and day 15. Fatigue was assessed at M0, M4, and M6 using the CFS, with a score ≥4 indicating clinically significant fatigue. Clinical and biological data were collected at each visit. Statistical analyses were performed using Jamovi version 2.4.14. Results. Ninety-four patients were included (mean age 57±9 years; 88% female). The median CFS score decreased from 4 [2-6] at M0 to 2 [0-4] at M4 (p<0.001) and remained stable thereafter through M6 (p=0.11 for the M4-M6 comparison). Disease activity improved in parallel, with the Disease Activity Score 28 using C-reactive protein (DAS28-CRP) decreasing from 4.7±1.1 at M0 to 2.9±0.9 at M4 and remaining stable at M6. Functional status assessed by Health Assessment Questionnaire also improved significantly. In multivariable analysis, higher M0 DAS28-CRP was associated with a greater reduction in fatigue. Conclusions. Rituximab therapy was associated with a significant improvement in fatigue in patients with RA, parallel to reductions in disease activity and functional disability.