Referral Rules for At-Risk Inflammatory Arthritis Save

A prospective primary care study of patients at-risk for inflammatory arthritis (IA) showed that progression to IA was most likely in those with high anti-CCP antibody titers levels and involvement of the hands/feet/ IA. Interestingly, progression to IA was also seen in those who were negative for CCP with hand or knee pain.

Musculoskeletal (MSK) symptoms are among the commonest reasons for primary care assessments; however, few individuals will be diagnosed with an inflammatory arthritis (IA) within the following year. The purpose of this study was to investigate, in individuals with new MSK symptoms, the association between patient factors and risk of progression to IA, in order to optimise primary care referrals to rheumatology.

Researchers from the University of Leeds, recruited 6780 patients with new non-specific MSK symptoms and no synovitis (July 2007 to May 2019). Prospective followup differed according to CCP status.  Those who were CCP positive were followed by Leeds rheumatologists. Those with negative CCP tests were sent a yearly questionnaire, and patient outcomes were ascertained from their general practitioners.

Among the 6780 patients, 3% were anti-CCP+, and 45% of these progressed to IA (mostly rheumatoid arthritis).  Predictors of progression to IA included high titer CCP+ (OR 9.42 [P < 0.001, 95% CI (3.13–28.30), hand pain (OR 2.74 [P = 0.043, 95% CI (1.03–7.27) and foot pain, (OR 4.10 [P = 0.003, 95% CI (1.59–10.54).

The 12 month follow-up on 5640 anti-CCP− individuals showed that only 0.93% progressed to IA. Predictors of IA progression in this group included hand pain (OR 2.51 [P = 0.018, 95% CI (1.17–5.39) and knee pain (OR 3.03 [P = 0.003, 95% CI (1.47–6.25) were associated with development of IA within 12 months.

This large prospective primary care study of at risk of IA patients confirms commonly advocated referral rules in patients with early MSK complaint -- CCP positivity and typical hand joints should prompt prioritised early rheumatology referral.