ABSTRACT
Objective To investigate the assoiation between rheumatoid arthritis(RA)and the pres- ence of the shared epitope(SE)of HLA-DRBI gene in Han nationality of Neimenggu population.Methods The method of DNA amplification with sequence-specific primers(PCR-SSP)was used to determine 17 alleles of HLA-DRB1*01,*04,*10 genotypes in 80 RA patients and 110 healthy controls from the Han nationality population in Neimenggu.Results The frequencies of SE were significantly increased in RA patiens com- pared with controls(48.8%:20%,P＜0.01).Epitope analysis revealed that the most predominant allele subtype of DR4(*0405)was usceptible sequence in Neimenggu patients with RA(28.8%:12%,P＜0.01).No statisticall significant difference of other subtypes of DR1,DR4 nd DR10 was noted including DRB1*0101(2.5%:0.9%), *0102(2.5%:0),*0103(1.25%:0.9%),*0104(2.5%:0),*0401(6.25:1.8%),*0402(3.75%:0.9%),*0403 (1.25%:1.8%),*0404(2.5%:1.8%),*0406(2.5%:2.7%),*0407(1.25%:0.9%),*0408(3.75 %:0.9%),*0409 (1.25%:0),*0410(2.5%:0.9%),*0411(0:0)and *1001(8.75%:4.5%)respectively.Logistic regression analy- sis showed that the disease of patients with SE homozgote was more severe than that of patients with heterozy- gote(P＜0.01).Conclusion The results suggest that there is an association between SE of HLA-DRBI gene and susceptibility and severity of RA,especially,HLA-DR4 subtypes are strongly associated with RA in Han nationality in Neimenggu population.