IL1 receptor antagonist genotypes. IL1 receptor antagonist genotypes are shown in controls (n=64),and patients with rheumatoid arthritis who had received surgery (n=50) and those who had not (n=50). Results are shown as number (%)
| 1*1 | 1*2 | 2*2 | 1*3 | 2*3 | |
| Controls | 50 (78) | 4 (6) | 8 (12) | 1 (2) | 1 (2) |
| Surgery | 42 (84) | 2 (4) | 4 (8) | 2 (4) | 0 |
| No surgery | 45 (90) | 0 | 4 (8) | 1 (2) | 0 |