Clinical, Laboratory, and Treatment Characteristics of Seropositive and Seronegative Rheumatoid Arthritis: A Real-World Cohort Study

Seropositive and seronegative rheumatoid arthritis (RA) are increasingly recognized as clinically and biologically distinct disease subsets, yet comparative real-world data remain limited. We aimed to compare the sociodemographic, clinical, laboratory, and treatment characteristics of patients with seropositive and seronegative RA. This retrospective, single-center study included 559 patients with RA followed between September 2023 and May 2025. Seropositivity was defined as rheumatoid factor and/or anti-cyclic citrullinated peptide antibody (anti-CCP) positivity. Sociodemographic, clinical, laboratory, and treatment characteristics were compared between seropositive and seronegative patients. Of 559 patients, 446 (79.8%) were seropositive and 113 (20.2%) were seronegative. Disease duration was significantly longer in seropositive patients (p