The effectiveness of rheumatoid arthritis treatment is negatively associated with signs of central sensitization

Abstract

Introduction. Modern treatment of rheumatoid arthritis faces such major problems as the lack of etiotropic therapy and the high cost of biological drugs. This necessitates a detailed analysis of the effectiveness of existing treatment methods and the study of factors that influence its results. The main goal of treating rheumatoid arthritis is to achieve remission or, if this is not possible, to reduce disease activity to a minimal level. One of the key factors influencing the course of the disease is a pronounced pain syndrome, which is due not only to inflammation of the joints, but also to the phenomenon of central sensitization, which makes the pain chronic even with adequate control of the inflammatory process. In this regard, this study aimed to assess the impact of symptoms associated with central sensitization on the effectiveness of standard treatments for rheumatoid arthritis. Materials and Methods. 122 patients with rheumatoid arthritis were examined. To assess disease activity, the DAS-28, SDAI, and CDAI were used. To assess the general health of patients, a visual analog scale (VAS) was used (patient-rated VAS-p and doctor-rated VAS-d). The functional status of patients was assessed using the Health Assessment Questionnaire – Disability Index. Symptoms associated with central sensitization (CS) were assessed using the Ukrainian version of the CSI questionnaire. Treatment efficacy was assessed using ACR20/50/70 criteria. Results. A recommended cutoff score was used to divide the sample into high and low CSI subgroups. Rheumatoid arthritis patients with high CSI score had worse post-treatment indicators (p<0.01) than patients with low CSI score: ESR – 20.1±5.54 vs. 14.53±7.51, DAS-28 – 5.1±0.49 vs. 4.47±0.91, SDAI – 28.8±6.74 vs. 20.1±7.26, CDAI – 26.54±6.49 vs. 20.6±6.54, VAS-p – 6.44±1.09 vs. 4.55±1.41, VAS-d – 5.5±0.99 vs. 4.08±1.02, HAQ – 1.3±0.44 vs. 0.76±0.52. These results suggest lower therapy efficacy in patients with more pronounced CS-associated symptoms. Analysis of rheumatoid arthritis treatment effectiveness according to ACR20 criteria found that after 12 weeks of therapy, 63.1% of patients were responders and 36.9% were non-responders. According to the ACR50 criteria, 29.5% of patients were responders after 12 weeks of therapy. Only patients with low CSI scores (5.4%) achieved ACR70, while there were no responders among patients with high CSI scores. It was found that patients with subclinical, mild, and moderate manifestations of CS demonstrated a significantly better response to treatment than those with severe and extreme manifestations of CS. Thus, 72.7% of patients with subclinical, mild, and moderate CS achieved the ACR20 criteria, while only 21.7% of patients with severe and extreme CS demonstrated a response to standard RA therapy according to this criteria (p<0.01). 35.4% of patients with subclinical, mild, and moderate forms of CS achieved the ACR50 criteria, while only 4.3% of patients with severe and extreme CS demonstrated improvement according to the specified criteria (p<0.01). Conclusions. Standard treatment of rheumatoid arthritis does not always provide remission, but helps reduce disease activity and improve the condition of patients, while severe CS makes it difficult to achieve a therapeutic effect. It has been found that severe CS-related symptoms are associated with more severe initial disease activity, reduced treatment efficacy, and worse functional status after 12 weeks of therapy as compared to mild CS-related symptoms, suggesting the need to consider additional treatment components to address these symptoms.