Comparison of seropositive and seronegative rheumatoid arthritis patients using or about to be initiated with biological DMARDS

Objective: Rheumatoid arthritis (RA) is an inflammatory, autoimmune systemic disease. This study aimed to compare the demographic, clinical characteristics, treatment choices, and treatment responses of seronegative (SN) and seropositive (SP) RA patients who were receiving or newly started biological treatment. Methods: The files and records of patients registered with Hacettepe University Biological Database with RA diagnosis who were planned to use biological disease-modifying antirheumatic drugs (b-DMARDs) between 2010-2024 were scanned. RA patients were divided into two groups as SPRA and SNRA. Demographic characteristics, disease duration, bDMARD use follow-up period, comorbidities, RA extra-articular findings, visual analog scale (VAS) global, VAS pain, VAS fatigue, Health Assessment Questionnaire-Disability index were recorded for RA patients included in the study. Results: Two thousand five hundred and fifty-nine patients were included in the study. Median age of the patients was 55 years and 2034 of them were female. 75% of the patients were SPRA, 25% were SNRA. Although the DAS-28 score did not create a statistically significant difference when compared between the two groups, the rate of patients with low disease activity was higher in the seronegative group, while the rate of patients with moderate and high disease activity was higher in the SPRA group. When patients were evaluated according to the disease activity score (DAS-28) disease activity score after b-DMARD treatment, the proportion of patients who achieved remission or low disease activity was higher in the seronegative group. Among extra-articular findings, the frequency of interstitial lung disease and sicca symptoms were higher in the SPRA group. Conclusion: SPRA and SNRA can be considered as two separate subtypes of RA with differences in clinical features, extra-articular involvement findings, disease activities, treatment choices and treatment responses.