Table 7

Predisposing effect of shared epitope genotypes on anticyclic citrullinated peptide antibody and rheumatoid factor seropositivity

aCCP

RF

SE groups

OR (95% CI)

P value

OR (95% CI)

P value

S1 (n = 24)

2.4 (1.1 to 5.4)

0.0113*

1.6 (0.9 to 2.9)

0.1245

S3D (n = 17)

2.3 (1.0 to 5.4)

0.0287*

1.7 (0.9 to 3.0)

0.1059

S1/S3D (n = 50)

2.3 (1.0 to 5.3)

0.0049**

1.6 (0.9 to 2.9)

0.0611

S2 (n = 11)

2.2 (0.9 to 5.2)

0.0995

1.6 (0.9 to 3.1)

0.1930

S3P (n = 28)

2.5 (1.1 to 5.6)

0.0075**

1.6 (0.9 to 3.0)

0.0563

S2/S3P (n = 47)

2.4 (1.1 to 5.5)

0.0025**

1.6 (0.9 to 2.8)

0.0687

aCCP = anticyclic citrullinated peptide antibodies; RF = rheumatoid factor; SE = shared epitope. OR (95% CI) and P values were calculated using Fisher's exact test to compare rheumatoid arthritis patients with RA patients with the X/X genotype (n = 12). *P < 0.05. **P ≤ 0.008 values are highly significant. Groups S1, S3D, S2 and S3P consisted of the pooled homozygotes (SS) and heterozygotes (SX) for each group. Group S1/S3D consisted of S1/S1, S1/X, S3D/S3D, S3D/X and S1/S3D. Group S2/S3P consisted of S2/S2, S2/X, S3P/S3P, S3P/X and S2/S3P.

Meyer et al. Arthritis Research & Therapy 2011 13:R160   doi:10.1186/ar3479