Proportion of RA patients and controls identified as ACPA+ by the ACPA biomarker panel*
| Total number of individuals | Number of ACPA+ individuals | Number of ACPA− individuals | % of ACPA+ individuals | |
|---|---|---|---|---|
| RA patients | 30 | 17 | 13 | 56.7 |
| CCP− | 16 | 3 | 13 | 18.8 |
| CCP+ | 14 | 14 | 0 | 100 |
| Controls | 48 | 2 | 46 | 4.2 |
| Healthy | 10 | 0 | 10 | 0 |
| SLE | 23 | 2 | 21 | 8.7 |
| Gout | 6 | 0 | 6 | 0 |
| PsA | 9 | 0 | 9 | 0 |
*ACPA positivity was defined as mean reactivity being three times that for the same antigen in samples from healthy controls. Individuals were considered ACPA+ if they were positive for ≥4 of the 16 RA-associated ACPAs listed in online supplementary table S1.
ACPA, anticitrullinated protein antibody; CCP, cyclic citrullinated peptide; PsA, psoriatic arthritis; RA, rheumatoid arthritis; SLE, systemic lupus erythematosus.