title: Rheumatoid arthritis association in Colombian population is restricted to HLA-DRB1*04 QRRAA alleles.
abstract: In most ethnic groups genetic susceptibility to rheumatoid arthritis (RA) is associated with certain HLA-DRB1 alleles encoding a similar sequence motif called the 'shared epitope' (SE) spanning amino acid positions 70 to 74 in the third diversity region of the outermost domain of the HLA-DRB1 molecule. We examined the association of the SE and RA in 83 Colombian women with established RA and 90 healthy controls. The group HLA-DRB1*04 was associated with RA with respect to controls (47% vs 18%, respectively. OR: 4.1, 95%CI: 2.1-8.2, P < 0.001). HLA-DRB1 alleles carrying the SE QRRAA, but not those carrying QKRAA or RRRAA, were associated with disease (OR: 3.7, 95%CI: 1.73-7.83, P = 0.0009). This association was stronger among HLA-DRB1*04 carriers (OR: 23, 95%CI: 1.3-414, P = 0.002). In our population, the SE QRRAA expressed in DRB1*04 alleles appears critical in identifying women with increased susceptibility to RA.
authors.affiliation: Rheumatology Unit, Corporación para Investigaciones Biológicas, Medellín, Colombia, South America. jmanaya@epm.net.co
authors.forename: J M
authors.initials: JM
authors.lastname: Anaya
authors.forename: P A
authors.initials: PA
authors.lastname: Correa
authors.forename: R D
authors.initials: RD
authors.lastname: Mantilla
authors.forename: M
authors.initials: M
authors.lastname: Arcos-Burgos
mesh_terms: D000328:Adult; D000483:Alleles; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001172:Arthritis, Rheumatoid / Q000235:genetics*; D003105:Colombia; D003430:Cross-Sectional Studies; D005260:Female; D018628:Gene Dosage; D020022:Genetic Predisposition to Disease; D006684:HLA-DR Antigens / Q000737:chemistry / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006579:Heterozygote; D006801:Humans; D008875:Middle Aged; D017434:Protein Structure, Tertiary
chemical_list: D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains