Nociplastic Pain Predicts Disease Activity and Hyperalgesia of Rheumatoid Arthritis Patients

Rheumatoid arthritis (RA) affects > 1.3 million people in the United States. RA is a chronic (long-lasting) autoimmune disease that mostly affects joints. Nociplastic pain has been reported in all musculoskeletal pain disorders, including RA. However, it has been mostly associated with fibromyalgia (FM) which is a widespread pain syndrome associated with insomnia, fatigue, cognitive difficulties, and dysfunction. 30 RA were recruited from UF Rheumatology Clinics. Healthy Controls (HC) were recruited from the community by advertising. HC had to be without joint disease. Laboratory evaluation for RF and CCP antibodies was performed. Disease activity was assessed by RP3, DAS28-ESR, and DAS28-CRP. Mechanical pain sensitivity was tested at joints and muscles. Nociplastic pain was measured according to the 2016 FM Criteria. Mechanical pain threshold was assessed with and electronic algometerResults: 28 RA patients were female. Mean age was 52.3 years. 15 HC were female. Their mean age was 51.4 years. More than 83% of patients were positive for RF or CCP. RA patients showed moderate disease activity (RP3: 3.3; DAS28-ESR: 4.07; DAS28-CRP: 3.9). Independent t-test showed a statistical difference of mechanical pain thresholds at all sites between RA patients and HC. The presence of nociplastic pain predicted increased clinical RA disease activity. The presence of nociplastic pain seems to worsen the clinical disease activity and mechanical hypersensitivity of RA patients. Thus, RA may benefit not only from immunological therapies but also chronic pain treatments.