AB1297 High prevalence of seronegative rheumatoid arthritisin a maya-yucateco indigenous population: a cohort community-based study

Background Eighty percent of people living with rheumatoid arthritis (RA) are seropositive. Recent studies show that seronegative RA is associated with a more aggressive clinical presentation; however, this association has not been studied in indigenous populations. Objectives To compare the clinical and radiographic characteristics, functioning and quality of life in a group of Maya-Yucateco indigenous patients with RA, based on their seropositivity Rheumatoid Factor (RF- IgM). Methods A community-based cohort was formed in 2014 with the aim of detecting and performing a community intervention in a Mayan Municipality in Mexico. Patients who fulfilled ACR/EULAR criteria 1987/2010 for RA were included and rheumatologists evaluated them every 3 months. All evaluations were conducted in the community with the support of trained translators and included: 1. Clinical examinations. 2. Laboratories (i.e. RF, ESR, CRP). 3. Radiographic evaluations. 4. Functioning (HAQ-DI) and quality of life (EQ5D-3L) assessments. 5. Pharmacological treatment. 6. Non-pharmacological treatment: individual and group exercises. A quantitative comparative analysis was conducted by dividing the cohort in seropositive and seronegative and comparing all variables measured using a χ2; test, Student’s t-test or Mann-Whitney U test, as well as Kruskall-Wallis test for the non-parametric variables. Results Twenty eight of 430 participants were diagnosed with RA (1.8%, CI95%; 1.2 to 2.6), for an incidence 0.72% (CI95% 0.3 to 1.2) in 4 years. Seventy-eight% were women, the mean age was 53.9 years (standard deviation (SD)=13.2) and the level of education was on average 2 years (0–5.5). We observed high prevalence of family history of rheumatic disease (75%), exposure to woodstove (96.1%), and a Chikungunya virus infection (10.7%) and RF- (65.3%). The treatment given was methotrexate in 64.2% as monotherapy, and 21.4% in combination therapy. NSAIDs were prescribed in 98.2%. Prednisone was prescribed at low doses ( The level of pain/discomfort assessed through EQ-5D3L dimension was significantly higher in the seropositive group in comparison with the seronegative group. No other differences were detected between these groups (see Table). RD rheumatic diseases; DAS-28 disease activity score; HAQ Health Assement Questionnaire. Conclusions The prevalence with negative RF is high in the community studied, however, no differences were observed in the variables studied, except in pain. Acknowledgements Funding: CONACYT-233777 Disclosure of Interest None declared