FRI544 Serological Profile In Rheumatoid Arthritis And Its Interplay With Autoimmune Thyroid Diseases

Abstract

Abstract Disclosure: T. Kolitz: None. S. Kivity: None. I. Tessler: None. Y. Marcus-Perlman: None. E. Izkhakov: None. I. Yaish: None. Y. Greenman: None. Objective: Autoimmune thyroid diseases (AITD) are the most common organ-specific autoimmune disorders, with an estimated prevalence of 5%. AITD encompass the clinical scope of Hashimoto’s thyroiditis (HT) and Graves’s disease (GD). Rheumatoid arthritis (RA) is a relatively common non-organ-specific autoimmune disease with an estimated global prevalence of 0.5-1%. Numerous studies have investigated the association of thyroid disorders and RA in various populations, but results were inconsistent. This study is aimed to assess the rate of AITD in RA patients and to further investigate these rates in subgroups of patients with seronegative RA, seropositive RA and dual-positive RA antibodies [i.e., positive anti-cyclic citrullinated peptide (CCP) and rheumatoid factor (RF)]. Methods: We used a big-data platform (MDClone Ltd., Israel) to create a cohort of RA patients with and without coexistent AITD. The cohort included 1316 patients who were treated in the Tel Aviv Sourasky Medical Center for any diagnosis between January 2008 and December 2022. Results: There were 340 men (25.8%) and 976 (74.2%) women in the cohort. The mean age at time of initial coding of RA diagnosis in our referral center was 62.5±15 years. AITD was found in 15.5% of the entire RA cohort. Hypothyroidism was the most common thyroid-associated diagnosis (in 95.8% of patients with RA and AITD). When RA patients were further sub-classified to seronegative, seropositive, and dual-positive RA, the rates of AITD were 11.8%, 17.6% and 25%, respectively (p=0.007). AITD rates in seropositive women and men were 20.6% and 8%, respectively (p<0.001). In the RA-seronegative subgroup, the rate of AITD was 15.6% in women and 2.7% in men (p<0.001). The mortality rates in RA-seronegative patients, RA-seronegative patients with AITD, RA-seropositive patients and RA-seropositive patients with AITD were 5.5%, 8.3%, 21.6% and 29.5%, respectively (p=0.05). Conclusion: Our findings suggest that the prevalence of AITD in patients with RA is associated with the specific serological profile, with highest rates in RA patients who are positive for both anti-CCP and RF. Randomized prospective studies are required to explore any cause-and-effect correlation and to delineate the impact of AITD on RA outcome and mortality rates. Presentation: Friday, June 16, 2023