RT Journal Article
SR Electronic
T1 Immunogenetic Risks of Anti-Cyclical Citrullinated Peptide Antibodies in a North American Native Population with Rheumatoid Arthritis and Their First-degree Relatives
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP 1130
OP 1135
DO 10.3899/jrheum.080855
VO 36
IS 6
A1 El-GABALAWY, HANI S.
A1 ROBINSON, DAVID B.
A1 HART, DONNA
A1 ELIAS, BRENDA
A1 MARKLAND, JANET
A1 PESCHKEN, CHRISTINE A.
A1 SMOLIK, IRENE
A1 MONTES-ALDANA, GABRIELA
A1 SCHROEDER, MARLIS
A1 FRITZLER, MARVIN J.
A1 CHEANG, MARY
A1 OEN, KIEM
YR 2009
UL http://www.jrheum.org/content/36/6/1130.abstract
AB Objective. To determine the prevalence of anti-cyclic citrullinated peptide (anti-CCP) antibodies in unaffected relatives of North American Native probands with rheumatoid arthritis (RA); and the associations of the shared epitope (SE) and HLA-DRB1*0901 with RA and anti-CCP antibodies. Methods. The subjects were RA probands, affected relatives, unaffected first-degree (FDR) and more distant relatives, and unaffected controls from the same population. HLA-DRB1 typing was determined by DNA sequencing and anti-CCP antibodies were determined by ELISA. Results. DRB1*0901, SE, and SE/DRB1*0901 genotypes were all associated with RA. SE/DRB1*0901, but not other SE genotypes, was associated with disease onset at age < 16 years. The frequency of anti-CCP antibodies was 82% in RA probands, 17% in FDR, 11% in more distant relatives, and 3% in controls. Among unaffected relatives, a significant increased risk of anti-CCP was associated with SE/DRB1*0901 genotype, but not with SE. Conclusion. An independent association of the non-SE allele DRB1*0901 with RA was confirmed in this population, and this allele in combination with a SE allele was associated with younger age at disease onset. FDR of RA probands have a higher prevalence of anti-CCP antibodies than more distant relatives and unrelated controls, suggesting a gradient of risk for disease development. Immunogenetic risks may act early in disease pathogenesis at the level of initiation of RA autoantibody formation; however, it is not clear what additional genetic and environmental risks are involved in progression to clinical disease.