Objective: To evaluate the role of HLA-DRB1 genotypes in the development and progression of the rheumatoid arthritis (RA) disease process.
Methods: 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.
Results: 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.
Conclusion: DRB1 alleles with SEs were associated with the development of polyarthritis but not with early radiographic progression of the disease process.