Influence of the HLA-DRbêta shared epitope on susceptibility to and clinical expression of rheumatoid arthritis in Chilean patients.
To analyse the influence of shared epitope positive HLA-DRB1 alleles (QKRAA or QRRAA)) on rheumatoid arthritis (RA) susceptibility and severity in Chileans, a population that exhibits a weak association with HLA-DR4.
Methods-Prevalence of alleles DRB1*01 and DRB1*04 alleles was determined by polymerase chain reaction amplification and sequence specific oligonucleotide hybridisation in 129 RA patients with defined clinical features and in 97 healthy controls.
The shared epitope was found in 70 (54%) of the RA patients and in 29 (30%) of controls (odds ratio (OR)=3 ; 95% confidence intervals (CI)=1.5,5.1 ; p=0.0004), and was present in a double dose in 20% of patients versus 4% of controls (OR=6 ; 95% CI=2,21 ; p=0.0009).
HLA-DRB1*0403 was the most prevalent DR4 subtype in controls (19%). HLA-DRB1*0404 or *0408 were the alleles most prominently associated with RA, 19% versus 6% in controls (OR=3 ; 95% CI=1.3,10 ; p=0.01).
The risk of RA in those carrying a double dose of the shared epitope was 7.5 times that seen in patients lacking the epitope.
Disease severity was moderate : 33% had extra-articular manifestations.
The double dose was associated with an increased risk of vasculitis or extra-articular manifestations.
However, 59 patients (46%) did not carry the shared epitope and 18 of them (31%) had extra-articular manifestations. (...)
Mots-clés Pascal : Polyarthrite rhumatoïde, Pathogénie, Symptomatologie, Epidémiologie, Prévalence, Système HLA-DR, Réaction chaîne polymérase, Déterminant antigénique, Ethnie, Homme, Chronique, Système ostéoarticulaire pathologie, Rhumatisme inflammatoire, Immunopathologie, Maladie autoimmune, Biologie moléculaire, Chilien
Mots-clés Pascal anglais : Rheumatoid arthritis, Pathogenesis, Symptomatology, Epidemiology, Prevalence, HLA-DR-System, Polymerase chain reaction, Antigenic determinant, Ethnic group, Human, Chronic, Diseases of the osteoarticular system, Inflammatory joint disease, Immunopathology, Autoimmune disease, Molecular biology
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0251870
Code Inist : 002B15D. Création : 11/06/1997.