Table 2.
Frequency and odds ratio for anti-VCP1, anti-VCP2, anti-HCP1 and anti-HCP2 antibodies separately and in combinations, in pre-symptomatic individuals and in patients with rheumatoid arthritis (RA) for disease development
| Antibodies | Antibody frequency in pre-symptomatic individuals (n = 521), % (95 % CI) | OR (95 % CI) | Sensitivity in patients with RA (n = 241), % (95 % CI) | OR (95 % CI) | Specificity, % (95 % CI) |
|---|---|---|---|---|---|
| VCP1 | 10.4 (8, 13.3) | 6.2 (2.4, 15.6) | 36.1 (30.3, 42.3) | 30.2 (12.0, 75.9) | 98.2 (95.6, 99.3) |
| VCP2 | 17.1 (14.1, 20.6) | 11.0 (4.4, 27.4) | 52.3 (46, 58.5) | 58.5 (23.3, 146.8) | 98.2 (95.6, 99.3) |
| HCP1 | 10.2 (7.9, 13.1) | 6.1 (2.4, 15.3) | 37.3 (31.5, 43.6) | 31.8 (12.7, 80.1) | 98.2 (95.6, 99.3) |
| HCP2 | 16.3 (13.4, 19.8) | 10.4 (4.2, 26.0) | 48.5 (42.3, 54.8) | 50.4 (20.1, 126.4) | 98.2 (95.6, 99.3) |
| CCP2 | 36.7 (32.6, 40.9)a | 21.9 (10.1, 47.4)a | 78.4 (72.8, 83.1) | 137.6 (61.2, 309.6) | 97.4 (94.6, 98.8) |
| VCP1 + VCP2 | 8.6 (6.4, 11.2) | 8.5 (2.6, 27.5) | 32.8 (27.7, 39.0) | 43.7 (13.6, 140.8) | 98.9 (96.6, 99.8) |
| VCP1 + HCP1 | 1.5 (0.7, 3.1) | - | 17.0 (12.8, 22.3) | 1.21 (1.1, 1.3) | 100 (98.3, 100) |
| VCP1 + HCP2 | 6.5 (4.7, 9) | 18.9 (2.6, 139.0) | 28.6 (23.3, 34.7) | 108.7 (15.0, 790.0) | 99.6 (97.7, 100) |
| VCP2 + HCP1 | 3.1 (1.9, 5) | - | 25.7 (20.6, 31.6) | 1.4 (1.3, 1.5) | 100 (98.3, 100) |
| VCP2+ HCP2 | 11.3 (8.7, 14.2) | 17.2 (4.2, 71.1) | 40.2 (34.3, 46.6) | 90.9 (22.1, 374.2) | 99.3 (97.1, 100) |
| HCP1 + HCP2 | 5.6 (3.9, 7.9) | 8.0 (1.9, 33.6) | 26.6 (21.4, 32.5) | 48.8 (11.8, 201.9) | 99.3 (97.1, 100) |
| VCP1 + CCP2a | 8.7 (6.6, 11.5) | 25.8 (3.5, 188.1) | 35.7 (29.9, 41.9) | 150.4 (20.7, 1090.3) | 99.6 (97.7, 100) |
| VCP2 + CCP2a | 15.8 (12.8, 19.1) | 25.2 (6.1, 103.2) | 52.3 (46, 58.5) | 147.9 (36.0, 608.2) | 99.3 (97.1, 100) |
| HCP1 + CCP2a | 8.3 (6.2, 11) | 24.5 (3.4, 179.2) | 35.7 (29.9, 41.9) | 150.4 (20.7, 1090.3) | 99.6 (97.7, 100) |
| HCP2 + CCP2a | 15.4 (12.6, 18.9) | 16.4 (5.1, 52.4) | 48.5 (42.3, 54.8) | 84.6 (26.4, 271.4) | 98.9 (96.6, 99.0) |
The antibodies are presented for the frequency of positivity, and with odds ratio (OR) and 95 % confidence interval (95 % CI). aFrequency in pre-symptomatic individuals, n = 518. VCP, viral citrullinated peptides derived from Epstein-Barr-virus encoded protein; HCP, antibodies against histone 4-derived citrullinated peptides, CCP cyclic citrullinated peptide