title: Association of specific amino acid sequence (QRRAA) of HLA-DRB1*0405 with rheumatoid arthritis in a Tunisian population.
abstract: This study aimed to investigate HLA-DRB1 alleles in rheumatoid arthritis (RA) patients from Tunisia and to examine the effect of these alleles on disease severity. HLA-DRBI alleles and sub-typing of DRBI*04 and *01 were determined in 90 patients and 100 healthy controls, by PCR-SSP. HLA-DRB1*04 was significantly higher in patients (51.1%) than in controls (27%) [OR=2.83, p=0.00066]. DRBJ*0405 was found to be the unique DR4 allele associated with RA (28.88% vs 6%) [OR=6.36, p=0.000059]. A significant decrease in the frequency of HLA-DRB1*0701 was observed in RA patients (16.66%) compared to controls (36%) [p=0.0026]. However, the frequency of patients carrying the shared epitope (SE) QRRAA, was slightly increased compared with controls (37.8% vs 23%) [OR=2.03, p=0.039]. We found that the presence of rheumatoid factor, HLA-DR4 and HLA-DRBI*0405 were not significantly associated with bone erosions or the presence of extra-joint involvement. In our population, the SE (QRRAA) expressed in DRBI*04 alleles is related to the susceptibility to RA but it is not involved in RA severity in Tunisia, while DRBI*0701 might protect against this disease.
authors: Laboratoire de Recherche en transplantation rénale et en immunopathologie, Department of Rheumatology, EPS Charles Nicolle, Tunis, Tunisia (LROISP03).
authors: T
authors: T
authors: Dhaouadi
authors: I
authors: I
authors: Sfar
authors: L
authors: L
authors: Abdelmoula
authors: R
authors: R
authors: Bardi
authors: S
authors: S
authors: Jendoubi-Ayed
authors: M
authors: M
authors: Makhlouf
authors: H
authors: H
authors: Aouadi
authors: T
authors: T
authors: Ben Abdallah
authors: R
authors: R
authors: Zouari
authors: K
authors: K
authors: Ayed
authors: Y
authors: Y
authors: Lakhoua-Gorgi