THE IMPACT OF SEROPOSITIVITY AND AGE ON LONG-TERM FOLLOW-UP DURATION IN RHEUMATOID ARTHRITIS

Abstract

Background and objectives: To investigate the predictive effects of demographic factors, acute phase reactants (ESR and CRP), serological markers (RF and Anti-CCP), and early biologic treatment strategies at diagnosis on the long-term follow-up duration at a tertiary referral center, from a ten-year perspective (2014-2024). Materials and Methods: This single-center, retrospective cohort study included 140 adult RA patients fulfilling the 2010 ACR/EULAR classification criteria. Baseline clinical characteristics, inflammatory, and autoimmune profiles of the patients were evaluated. The primary endpoint, long-term follow-up duration (months), was calculated based on the patients' first and last registry dates at the rheumatology outpatient clinic. The obtained data were analyzed using descriptive statistics, parametric/non-parametric comparison tests, and correlation analyses. Results: The study cohort, with a mean age of 63.18 ± 15.30 years, consisted of 66.4% female patients. Statistical analyses demonstrated that the mean follow-up duration of patients in the <65 age group (36.24 ± 42.37 months) was significantly longer compared to the ≥65 geriatric group (21.69 ± 30.82 months) (p = 0.023). Gender, geographical residence, and the use of biologic agents in the first year did not exert a significant impact on the follow-up duration. No statistical correlation was observed between baseline acute phase reactants (ESR and CRP levels) and cumulative follow-up duration. Conversely, the baseline serological profile was identified as a dramatic predictor of the follow-up period. The follow-up duration was profoundly longer in Rheumatoid Factor (RF) positive patients compared to negative ones (45.90 months vs. 10.07 months; p < 0.001) and in Anti-CCP positive patients compared to negative ones (37.12 months vs. 22.67 months; p = 0.024). While the follow-up duration remained limited to an average of 8.59 months in patients negative for both autoantibodies, this duration increased to 43.02 months in patients positive for at least one autoantibody (composite seropositivity) (p < 0.001). Conclusion: In RA patients, the fundamental factor determining the need for long-term follow-up in a specialized rheumatology unit is the underlying autoimmune and serological phenotype of the disease, rather than the initial transient acute inflammatory burden. Seropositivity (RF and/or Anti-CCP) is a robust prognostic biomarker that guides clinical practice in identifying aggressive disease forms that require high-risk and persistent specialized care in long-term disease management.