Table 5.
Relative risk for developing rheumatoid arthritis in patients, stratified for anti-cyclic citrullinated peptide (anti-CCP) antibodies
| Non-T carrier (CC) | T carrier (CT, TT) | |||
| Cases/controls | Relative risk (95% confidence interval) | Cases/controls | Relative risk (95% confidence interval) | |
| Anti-CCP antibody-positive | ||||
| Smoking-negative | 59/511 | 1.00 | 37/146 | 2.17 (1.41–3.35) |
| Smoking-positive | 142/192 | 6.29 (4.51–8.77) | 73/50 | 12.54 (8.11–19.40) |
| Anti-CCP antibody-negative | ||||
| Smoking-negative | 47/511 | 1.00 | 17/146 | 1.36 (0.80–2.33) |
| Smoking-positive | 60/192 | 3.71 (2.51–5.46) | 23/50 | 5.87 (3.46–9.95) |
The combination of carriage or not of the 1858T variant of the PTPN22 gene and ever or never smoking were compared for groups stratified for anti-CCP antibodies.