Influence of Anti-Carbamylated Protein Antibodies on Disease Activity and Joint Erosions in Seronegative and Seropositive Rheumatoid Arthritis.

Anti-carbamylated protein (anti-CarP) antibodies are promising biomarkers in rheumatoid arthritis (RA), although their significance in seronegative disease (SNRA) remains uncertain. To assess the influence of anti-CarP antibodies on disease activity and erosive joint damage in SNRA patients. In RA patients, rheumatoid factor (RF), anti-citrullinated protein antibodies, and anti-CarP antibodies were measured. Disease activity was assessed using DAS28-CRP and SDAI indices, while musculoskeletal ultrasound identified bone erosions. A total of 77 patients were enrolled, comprising 49 with seropositive RA (SPRA) and 28 with SNRA. Notably, 28