Association between HLA-DR B1 and clinical features of adult onset Still's disease in Korea.

Objective: To determine whether HLA-DR alleles are associated with the development and clinical features of Adult Onset Still's Disease (AOSD) in Korea.
Methods: Forty-seven patients (41 women, 6 men, mean age at diagnosis 31.6 yr) meeting Yamaguchi's criteria for AOSD and 144 healthy controls were enrolled in this study. The patients with AOSD were subdivided into groups according to their chronicity: monocyclic systemic, polycyclic systemic, and chronic destructive type, and were furthermore classified as non-articular, oligoarticular or polyarticular types (having arthritis involving 5 or more joints) according to the extent of articular involvement. HLA-DRB1 genotypes were assessed by PCR-SSOP.
Results: Patients with AOSD had more frequent DRB1*12 (p = 0.028, relative risk (RR) = 2.27, 95% confidence interval (CI): 1.08-4.80) and DRB1*15 (p = 0.013, RR = 2.16, 95% CI: 1.17-4.00). They had less frequent DRB1*04 (p = 0.006, RR = 0.35, 95% CI: 0.16-0.75) compared to controls. DRB1*14 (p = 0.011, RR = 3.80, 95% CI: 1.27-11.31) were associated with the monocyclic systemic type.
Conclusion: Korean AOSD patients had more frequent DRB1*12 and DRB1*15, and less frequent HLA-DRB1*04. The patients with the monocyclic systemic type had more frequent DRB1*14 alleles. This study suggests that Korean AOSD patients have distinct immunogenetic profiles, and that it would be valuable to assess the relationships between HLA-DRB1 genes and polymorphisms of proinflammatory cytokines in the pathogenesis of AOSD.