Chikungunya-induced arthritis in Reunion Island: a long-term observational follow-up study showing frequently persistent joint symptoms, some cases of persistent Chikungunya IgM positivity and no anti-CCP seroconversion after 13 years.

: Inflammatory joint symptom persistence after 13 years was associated with more frequent autoantibody positivity, persistent Chikungunya-IgM positivity, immunosuppressant use, radiographic damage and higher Chikungunya-IgM and IgG levels in 30 patients diagnosed with Chikungunya-related chronic inflammatory rheumatic diseases in Reunion Island.After the 2005-2006 Chikungunya outbreak in Reunion Island, among 159 patients initially referred to a rheumatologist for post-Chikungunya chronic musculoskeletal pain, 73 were diagnosed with Chikungunya-related chronic (>3 month duration) classifiable inflammatory rheumatic diseases. Thirty of these 73 patients were clinically evaluated by a second rheumatologist in 2018-2019. Inflammatory joint symptoms persisted in 17/30 patients after 13 years. In the symptom persistence subgroup, autoantibody (antinuclear or ACPA) positivity was significantly more frequent (without any seroconversion), Chikungunya IgG and IgM levels were higher, long-term IgM positivity and radiographic damage more frequent, five patients were still treated by methotrexate, 3 by TNF-blockers.