title: An extended HLA-DQ-DR haplotype rather than DRB1 alone contributes to RA predisposition.
abstract: In the present study, we tested our hypothesis on the role of a DQ-DR haplotype in rheumatoid arthritis (RA) predisposition. Using two groups of patients and controls, one from The Netherlands and one from Switzerland, we found that DQA1*0301-homozygous and DQA1*0301//DQA1*0101/04-heterozygous individuals are highly predisposed to RA in both populations, while DQA1*0101/04-homozygous are not. The DQA1*0301-DRB1*0403/06/07 and DQA1*0301-DRB1*0901 haplotypes are not associated with RA by themselves but strongly increase the risk of developing disease in DQA1*0301- and DQA1*0101/04-heterozygous. DRB1 alleles carrying the motif DERAA in their third hypervariable region, i.e., *0103, *0402, *1102, *1103, *1301, and *1302, provide a long-lasting protection against RA in DQA1*0101/04- but not in DQA1*0301-positive individuals. These data show that considering both DQ and DR gives a better distinction between patients and controls than the shared epitope hypothesis.
authors.affiliation: Department of Immunohaematology and Blood Bank, Leiden University Medical Centre, Albinusdreef 2, PO Box 9600, 2300 RC Leiden, The Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Zanelli
authors.forename: T W
authors.initials: TW
authors.lastname: Huizinga
authors.forename: P A
authors.initials: PA
authors.lastname: Guerne
authors.forename: T L
authors.initials: TL
authors.lastname: Vischer
authors.forename: J M
authors.initials: JM
authors.lastname: Tiercy
authors.forename: W
authors.initials: W
authors.lastname: Verduyn
authors.forename: G M
authors.initials: GM
authors.lastname: Schreuder
authors.forename: F C
authors.initials: FC
authors.lastname: Breedveld
authors.forename: R R
authors.initials: RR
authors.lastname: de Vries
mesh_terms: D001172:Arthritis, Rheumatoid / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006683:HLA-DQ Antigens / Q000235:genetics*; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006239:Haplotypes; D006579:Heterozygote; D006720:Homozygote; D006801:Humans
chemical_list: D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains