Risk of antibody-positivity predicted by HLA-SE, smoking and HLA-SE+smoking in patients with RA and their first-degree relatives
| Patients with RA | First-degree relatives | |||||
|---|---|---|---|---|---|---|
| Antibody | SE | Smoking ever | SE+smoking ever | SE | Smoking ever | SE+smoking ever |
| IgG-ACPA | 4.71 (1.84 to 12.05) | 2.17 (0.90 to 5.23) | 19.33 (2.54 to 147.21)* | 0.55 (0.25 to 1.21) | 1.37 (0.63 to 2.95) | 0.71 (0.28 to 1.81) |
| IgA-ACPA | 2.03 (0.96 to 4.30) | 1.89(0.94 to 3.79) | 2.81 (1.27 to 6.24) | 0.47 (0.22 to 0.97) | 1.36 (0.65 to 2.85) | 0.76 (0.31 to 1.86) |
| IgM-ACPA | 1.30 (0.64 to 2.63) | 2.33(1.21 to 4.48) | 2.17 (1.07 to 4.00) | 0.76 (0.35 to 1.64) | 0.79 (0.36 to 1.73) | 0.79 (0.31 to 2.02) |
| IgG+IgA+IgM-ACPA | 1.78 (0.84 to 3.77) | 2.39 (1.21 to 4.71) | 2.98 (1.51 to 5.89) | 0.20 (0.02 to 1.87) | 1.14 (0.22 to 5.82) | 0.71 (0.08 to 6.48) |
| IgM-RF | 1.85 (0.86 to 4.0) | 1.76 (0.87 to 3.58) | 2.45 (1.10 to 5.46) | 0.75 (0.30 to 1.88) | 0.75 (0.30 to 1.88) | 0.43 (0.12 to 1.54) |
| IgA-RF | 1.36 (0.62 to 2.96) | 2.31 (1.11 to 4.78) | 2.23 (0.99 to 4.98) | 1.11 (0.51 to 2.38) | 1.61 (0.73 to 3.55) | 1.21 (0.50 to 2.94) |
| IgM+IgA-RF | 1.47 (0.71 to 3.05) | 2.16 (1.11 to 4.23) | 2.53 (1.21 to 5.28) | 0.58 (0.18 to 1.93) | 0.97 (0.31 to 3.03) | 0.24 (0.03 to 1.91) |
Values are OR (95% CI).
↵* All ever-smoking patients with RA with SE had IgG isotype antibodies. To permit this calculation, one of these patients was recorded as IgG negative.
ACPA, anti-citrullinated protein/peptide antibody; HLA, human leucocyte antigen; RA, rheumatoid arthritis; SE, shared epitope.