To evaluate the role of HLA-DRB1 genotypes in the development and progression of the rheumatoid arthritis (RA) disease process.
Patients with polyarthritis of < 1 year in duration were consecutively enrolled in the study. Other inclusion criteria were no diagnosis of inflammatory diseases other than RA, and no history of taking disease-modifying antirheumatic drugs or steroids. Patients were evaluated every 4 weeks, and radiographs of the hands/wrists and feet were taken at presentation and 1 year later. HLA-DRB1 genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism methods.
We enrolled 198 patients (median disease duration 5.0 months) and 150 controls. The frequency of individuals with DRB1*0405 and *0410 was significantly higher in the patients than in the controls. Homozygous states for DRB1 alleles with the RA-related shared epitope (SE) were associated with increased susceptibility for the development of polyarthritis (odds ratio 3.4, 95% confidence interval 1.5-7.7). None of the DRB1 alleles or SE genotypes correlated with the presence of bone erosion at presentation or 1 year later.
DRB1 alleles with SEs were associated with the development of polyarthritis but not with early radiographic progression of the disease process.