Table 1 Laboratory tests for citrullinated antigens
From: 21st European Workshop for Rheumatology Research, Vienna, Austria, 1–4 March 2001
Author | Substrate | Method | Sensitivity | Specificity | Comments |
|---|---|---|---|---|---|
Bozic (P4) | Cyclic citrullinated peptide (CCP) | ELISA | 58% | ND | Tested 97 RA patients who were RF-positive or RF-negative. |
Small study, lower sensitivity than previously reported. | |||||
Union (P6) | In vitro citrullinated filaggrin; 2 citrullinated peptides | Line immunoassay | 65% (using 3 markers); 61.8% (using 2 peptides) | 97.6% (using 3 markers); 98.4% (using 2 peptides) | Tested 335 RA patients and 254 patients with non-RA rheumatologic conditions retrospectively. Results similar to those reported previously for CCP. |
Vincent (P7) | Deiminated recombinant rat filaggrin (ArFA); antikeratin antibodies | ELISA+ indirect immuno-fluorescence of rat esophagus | 67% | <99% | Tested 714 patients with rheumatic disease, of whom 241 had RA. Requires sequential testing to maintain utility at 99%. The sensitivity for arFA ELISA alone (at 95% specificity) was 75%. |