Characteristics of Patients With Early-Onset Arthritis in Latin America: Description of the REPANARC Cohort.

BACKGROUND: While many studies have tried to show that early intervention improves the clinical outcomes of early-onset arthritis, only a few were carried out in Latin America. OBJECTIVES: The aim of this study was to describe the Pan-American Registry of Early-Onset Arthritis (REPANARC) project and report the preliminary outcomes of a cohort of patients. METHODS: The REPANARC cohort consisted of a sample of patients from 6 Latin American countries. Patients with arthritis of 1 or more joints of 1-year duration or less were assessed by a rheumatologist during 6 consecutive clinical visits for a follow-up period of 2 years. The registry included clinical characteristics, medical history, physical examination, disease activity, analytical chemistries, imaging, current treatment, and a set of patient-reported outcome measures evaluating disability, psychological distress, and quality of life. RESULTS: A total of 173 patients were included with mean age of 41.9 ± 13.2 years; 83.8% were women. The predominant presentations at onset were insidious, polyarticular, additive, bilateral, and symmetrical. The initial diagnoses were rheumatoid arthritis (50.6%), undifferentiated arthritis (40.5%), and other arthritis (8.9%). With Disease Activity Score in 28 Joints, 76.9% had moderate to high disease activity, and 61.9% had moderate to severe disability (Health Assessment Questionnaire). Considering undifferentiated arthritis, 60.3% persisted undifferentiated, 29.4% evolved as rheumatoid arthritis, 4.4% remained self-limited, and 5.9% to other forms. The frequencies of depression and anxiety were high as measured with the Hospital Anxiety and Depression Scale, and approximately 20% had significant decrements in quality of life measured with the Medical Outcomes Study Short-Form 36 Health Survey Version 2. Mean time from the first symptoms to the first visit to a rheumatologist was 126 days. Shorter delays were confirmed to be associated with better outcomes. CONCLUSIONS: The REPANARC project is a useful tool to provide valuable information regarding patients with early-onset arthritis attending rheumatology centers in Latin-America.