To explore the role of HLA-DRB1 genes in the development of rheumatoid arthritis (RA) and the correlations between HLA-DR alleles and clinical manifestations of patients with RA.
86 patients with rheumatoid arthritis and 106 race matched controls were studied in whom HLA-DR typing was performed by the method of DNA amplification with sequence-specific primers (PCR-SSP). The subtypes of HLA-DR4 were determined by the method of hybridization of PCR products with sequence-specific oligonucleotides (PCR-SSO). The absence or presence of HLA-DR4 and its subtypes was correlated with the clinical and serological characteristics of the patients.
Compared with controls, an increased gene frequency of HLA-DR4 (48.8% vs 17.9%, P < 0.001) and a decreased frequency of HLA-DR7 (16.3% vs 27.4%, P = 0.06) were found. The DRB1* 0405 account for 61.9% of DR4+RA patients and 21.1% of DR4+ controls (P < 0.01). There was no difference between the DR4+ and DR4- patients with respect to age, sex, duration of disease, rheumatoid factor (RF), extra-articular manifestations including secondary Sjogren's syndrome. According to the wrist X-ray stage, the patients of DR4+ were more severe than that of DR4- (P < 0.05).
HLA-DR4 and DR4 subtype of DRB1*0405 are related to the development of RA in Chinese. HLA-DR4 can be a useful prognostic marker in the patients with RA.