Associations of age and ACPA positivity in SERA FDR.
| Unadjusted OR (95% CI) | Adjusted OR (95% CI) | |
|---|---|---|
| Anti-CCP3.1 | 1.04 (1.02–1.05) | 1.03 (1.02–1.05)1 |
| Anti–CCP-IgA | 1.04 (1.03–1.06) | 1.05 (1.03–1.06)2 |
| Anti–CCP-IgG | 1.01 (0.99–1.03) | 1.004 (0.98–1.03)3 |
↵1 Adjusted for BMI and RF.
↵2 Adjusted for BMI, sex, and education.
↵3 Adjusted for RF and education. ACPA: anticitrullinated protein antibodies; SERA: Studies of the Etiology of Rheumatoid Arthritis; FDR: first-degree relatives; BMI: body mass index; RF: rheumatoid factor; anti-CCP: anticyclic citrullinated peptide antibodies.