Half of Subclinical Synovitis Patients May Remit Save

Ultrasound subclinical synovitis is found in a third of individuals at risk of rheumatoid arthritis (RA) patients; in half of these, subclinical synovitis resolves with a favorable outcome.

This was a single-centre, prospective, UK cohort study of CCP-positive adults with clinically suspect arthralgia (new non-specific musculoskeletal symptom but no synovitis) referred for rheumatologic evaluation that included serial assessments (blood tests, patient questionnaires, and a musculoskeletal ultrasound) for 12 months

Between 2008 and 2020, 451 participants were enrolled in the CCP study and 122 (27%) individuals had subclinical synovitis at baseline. 12 month data was available in 90 (74%).

Subclinical synovitis resolved in 43 (48%), and persisted in 47 (52%) participants, 27 (57%) of whom developed clinical synovitis within 12 months.

Subclinical synovitis resolution by 12 months was predicted by low CCP titres (RR 1·52, 95% CI 1·04-2·22), negative rheumatoid factor (1·54, 0·92-2·58), subclinical synovitis in only one joint (1·62, 1·04-2·50), and an erythrocyte sedimentation rate of 15 mm/h or lower (1·82, 1·15-2·87).  If all four factors were present, subclinical synovitis resolved in 7/7 (100%), but in only one (7%) of 14 participants with none of the factors were present.

The presence of subclinical synovitis and CCP positivity in these early MSK patients does not necessarily portend a future of chronic inflammatory arthritis.