Cross-reactivity of human ACPA. Quantification of antibody reactivity in serum and affinity-purified ACPA is reported in units/mg of IgG.
| Serum | Purified ACPA | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Anti-CCP2 | Anti-CitJED | Anti-HomoCit JED | Anti-Cit Fib | Anti-HomoCit Fib | Anti-CCP2 | Anti-CitJED | Anti-HomoCit JED | Anti-Cit Fib | Anti-HomoCit Fib | |
| 1 | 55 | 5 | 40 | 3 | 3 | 5954 | 1286 | 7601 | 599 | 312 |
| 2 | 66 | 8 | 121 | NA | 2 | 3831 | 1667 | 11,016 | NA | 198 |
| 3 | 136 | 7 | 49 | 4 | 3 | 3987 | 599 | 2880 | 206 | 36 |
| 4 | 26 | 3 | 26 | 3 | NA | 6307 | 837 | 9317 | 1178 | NA |
| 5 | 173 | 23 | 41 | 25 | NA | 5465 | 798 | 2242 | 1130 | NA |
NA: a patient value that was negative or borderline; HomoCit: homocitrullinated; ACPA: anticitrullinated protein/peptide antibodies; anti-CCP2: anticyclic citrullinated peptide.