Table 2.
Frequency of ACPA positivity in 287 RA patientsa
| Antigen | Peptide sequence | Percent of patients |
|---|---|---|
| cCK13‐1 | 444TSNASGR‐cit‐TSDV‐cit‐RP458 | 24.0 |
| cCK13‐2 | 444TSNASGR‐cit‐TSDVR‐cit‐P458 | 0 |
| cFIBβ | 36NEEGFFSA‐cit‐GHRPLDKK52 | 66.2 |
| cTNC5 | 2176EHSIQFAEMKL‐cit‐PSNF‐cit‐NLEG‐cit‐cit‐KR2200 | 50.5 |
| CEP‐1 | 5KIHA‐cit‐EIFDS‐cit‐GNPTVE21 | 39.4 |
| cVIM | 59VYAT‐cit‐SSAV‐cit‐L‐cit‐SSVP74 | 32.1 |
| CCP‐2 | – | 84.5 |
a
Antibody sensitivity was 98% for all protein antigens. ACPA = anti–citrullinated peptide antibody; RA = rheumatoid arthritis; cCK13‐1 = citrullinated cytokeratin 13–derived peptide 1; cFIBβ = citrullinated fibrinogen β; cTNC5 = citrullinated tenascin‐C; CEP‐1 = citrullinated α‐enolase peptide 1; cVIM = citrullinated vimentin; CCP‐2 = cyclic citrullinated peptide 2.