A new classification of HLA-DRB1 alleles differentiates predisposing and protective alleles for autoantibody production in rheumatoid arthritis

Table 2 Relationship between HLA-DRB1 allele carrier status and rheumatoid factor status in French patients with early rheumatoid arthritis

	Carrier status		Odds ratio (95% confidence interval)	P	P for trend
	Yes	No
S1 carrier
Rheumatoid factor-positive	31 (55.4)	79 (75.9)	0.39 (0.19–0.83)	0.0118	0.0051*
Rheumatoid factor-negative	25 (44.6)	25 (24.0)
S2 carrier
Rheumatoid factor-positive	49 (83.1)	61 (60.4)	3.21 (1.39–7.9)	0.0028*	0.0049*
Rheumatoid factor-negative	10 (16.9)	40 (39.6)
S3P carrier
Rheumatoid factor-positive	57 (74.0)	53 (63.9)	1.61 (0.78–3.38)	0.1766	0.4478
Rheumatoid factor-negative	20 (26.0)	30 (36.1)
S3D carrier
Rheumatoid factor-positive	19 (51.4)	91 (74.0)	0.37 (0.16–0.86)	0.0145	0.0209
Rheumatoid factor-negative	18 (48.6)	32 (26.0)

Data presented as n (%). Status for rheumatoid factor among 160 patients with early rheumatoid arthritis, carrying the different HLA-DRB1 alleles encoding the shared epitope classified into four groups according to the new classification. Odds ratios, 95% alpha-risk confidence interval and P value for exact Fisher test. The dose effect was investigated for alleles positively or negatively associated with immunological markers using tests for trend of the log odds. *Significant after correcting for multiple testing according to the Benjamini–Yekutieli 2001 method at an overall critical P value of 5%.

ISSN: 1478-6362