SAT0562 Chikungunya fever in patients with prior rheumatic diseases: is it more severe?

Background Chikungunya fever (CF) is an infectious disease caused by a RNA virus and its transmission occurs by the inoculation of the virus by the female bite of Aedes aegypti mosquito. In Brazil, where the vetor is endemic, the virus rapidly disseminated and there was an epidemic, specially in the Northeast region of the country with 263.980 notified cases in 2016. It is known that CF may have a chronic course with articular symptons, however there is not consistent data in the medical literature on CF evolution in patients with prior rheumatic diseases. Objectives To assess whether there is any difference in the characteristics of articular manifestations of CF in patients with prior inflammatory rheumatic diseases (IRD), non-inflammatory rheumatic diseases (NIRD) and controls (patients with no diagnosed prior rheumatic diseases). Methods Cross-sectional study using a database from CHIKBRASIL cohort. Patients enrolled had clinical and epidemiological characteristics of CF and were classified in three groups: IRD (rheumatoid arthritis, axial spondyloarthritis and systemic lupus erythematosus), NIRD (fibromyalgia and osteoarthritis) and controls (no prior rheumatic diseases). Results A total of 150 patients were enrolled. There were 55 patients with IRD, 40 patients with NIRD and 55 controls, paired by age and sex. There were no differences in acute phase symptoms in the groups. There a was more frequent occurrence of arthritis in patients with IRD compared to NIRD (p=0.001) and to controls (p=0.002). In 89.1% of the patients with IRD there was an underlying disease exacerbation and 74% described an expressive worsening of symptoms compared to the period prior to infection. Patients with IRD had an increase in the current dose of corticosteroids (median 10mg, IQR 10–20) compared to previous dose used (median 6mg, IQR 5–10) after the onset of CF (p=0.0007). Importantly, there was more methotrexate prescription (23.5%) in IRD group, compared to NIRD group (0, p-0.001) and to controls (3.7%, p=0.003). Conclusions Patients with IRD and CF presented significantly more arthritis compared to NIRD or to controls. CF seems to induce underlying rheumatologic disease exacerbation in patients with inflammatory disease and a more aggressive therapeutic approach might be necessary in this group of patients. Disclosure of Interest None declared