Results of simple conditional logistic regression analyses of the different isotypes of anti-CCP2 antibodies, RFs, HLA-SE, PTPN22 1858T and smoking with first-degree relatives and patients with RA as dependent variable
| Factor | OR (95%CI) | p Value |
|---|---|---|
| IgG-CCP | 5.80 (3.61 to 9.30) | <0.0001 |
| IgA-CCP | 2.47 (1.74 to 3.51) | <0.0001 |
| IgM-CCP | 1.46 (1.07 to 1.99) | <0.05 |
| IgA-RF | 3.12 (2.16 to 4.50) | <0.0001 |
| IgM-RF | 3.64 (2.50 to 5.29) | <0.0001 |
| HLA-SE | 1.56 (1.00 to 2.42) | <0.05 |
| PTPN22 1858T | 1.23 (0.83 to 1.82) | NS |
| Smoking | 1.28 (0.92 to 1.78) | NS |
| Age | 1.02 (1.01 to 1.03) | <0.01 |
| Sex | 1.28(0.92 to 1.79) | NS |
CCP, cyclic citrullinated peptide; RA, rheumatoid arthritis; RF, rheumatoid factor; HLA-SE, human leucocyte antigen shared epitope.