Association between the HLA-DRB1 gene and clinical features of systemic sclerosis in Korea

Objective: To determine whether HLA-DR alleles are associated with the development and clinical features of systemic sclerosis (SSc) in Koreans. Methods: Seventy-nine patients (74 women and five men; 45 diffuse types and 34 limited types; mean age at diagnosis 43.9 years) fulfilling the American College of Rheumatology (ACR) classification criteria for SSc were enrolled. The controls were 144 healthy, disease-free Koreans. HLA-DRB1 genotypes were assessed by the polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSOP) method. Results: The HLA-DRB1*15 allele was increased in anti-topoisomerase I autoantibody (anti-topo I)-positive SSc patients [p=0.003, p corrected (p_corr)=0.039, odds ratio (OR)=3.43, 95% confidence interval (CI) 1.45-8.13] compared with controls. The DRB1*11 allele was also observed more frequently in anti-topo I-positive SSc than in controls (13.3% vs. 4.2%) but not statistically significant (p=0.053, p _corr=0.689). In patients with SSc, the DRB1*04 allele was associated with subcutaneous calcinosis (p=0.048, OR=4.56, 95% CI 1.07-19.37). Patients with overlap syndrome showed a negative association with the DRB1*04 allele (p=0.036, OR=0.26, 95% CI 0.08-0.91). Conclusion: The HLA-DRB1*15 allele was associated with the development of anti-topo I-positive SSc in Koreans. In addition, the DRB1*04 allele was associated with certain clinical features in SSc patients.