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

Table 3 Relationship between HLA-DRB1 allele carrier status and anticitrullinated protein/peptide autoantibody status in French patients with early rheumatoid arthritis

	Carrier status		Odds ratio (95% confidence interval)	P	P for trend
	Yes	No
S1 carrier
CCP2-positive	32 (57.1)	78 (75.0)	0.44 (0.21–0.94)	0.0312	0.0134
CCP2-negative	24 (42.9)	26 (25.0)
AhFibA-positive	31 (55.4)	77 (74.0)	0.43 (0.21–0.91)	0.0213	0.0113
AhFibA-negative	25 (44.6)	27 (26.0)
CCP2-positive
CCP2-negative	49 (83.1)	61 (60.4)	3.21 (1.39–7.9)	0.0028*	0.0049*
AhFibA-positive	10 (16.9)	40 (39.6)
AhFibA-negative	50 (84.8)	58 (57.4)	4.12 (1.75–10.49)	0.0004*	0.0003*
CCP2-positive	9 (15.2)	43 (42.6)
S3P carrier
CCP2-positive	61 (79.2)	49 (59.0)	2.65 (1.24–5.74)	0.0066*	0.0014*
CCP2-negative	16 (20.8)	34 (41.0)
AhFibA-positive	61 (79.2)	47 (56.6)	2.92 (1.38–6.32)	0.0025*	0.0035*
AhFibA-negative	16 (20.8)	36 (43.4)
S3D carrier
CCP2-positive	17 (45.9)	93 (75.6)	0.27 (0.12–0.63)	0.0011*	0.0009*
CCP2-negative	20 (54.1)	30 (24.4)
AhFibA-positive	19 (51.4)	89 (72.4)	0.4 (0.18–0.93)	0.0266	0.0145
AhFibA-negative	18 (48.6)	34 (27.6)

Data presented as n (%). Status for anticyclic citrullinated peptides (anti-CCP2) antibodies or antideiminated human fibrinogen autoantibodies (AhFibA) 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