Association of human leukocyte antigen class II genes with autoantibody profiles, but not with disease susceptibility in Japanese patients with systemic sclerosis

Object: To examine the role of human leukocyte antigen (HLA) class II genes in the development of systemic sclerosis (SSc) as well as in the clinical and serologic expression of SSc in patients, Methods: HLA-DRB1, DRB3, DRB4, DQB1, and DPB1 alleles were determined by ge notyping; and serum antinuclear antibodies were identified using indirect i mmunofluorescence, double immunodiffusion and immunoprecipitation, Patients: One hundred and five Japanese patients with SSc and 104 race-matc hed healthy controls. Results: Frequencies of DRB1 and DQB1 alleles were not different between SS c patients and healthy controls, while DPB1*0901 was marginally increased i n SSc patients, In contrast, SSc-related autoantibodies were closely associ ated with the clinical features. HLA class II genes were detected as follow s: anti-DNA topoisomerase I antibody with diffuse cutaneous involvement, pu lmonary fibrosis, and DRB1*1502-DQB1*0601-DPB1*0901; anti-U1RNP antibody wi th overlapping features of lupus and/or myositis and DRB1*0401/*0802-DQB1*0 302; and anticentromere antibody with limited cutaneous involvement and DRB 1*0101-DQB1*0501-DPB1*0402. In the analysis of the association of HLA class II and the clinical features in SSc patients significant differences were obtained only for the increased frequencies of arthritis and rheumatoid fac tor in patients with DRB1*0405 compared to those without. Conclusion: HLA class II genes strongly influence the production of SSc-rel ated autoantibodies rather than the development of SSc, In addition, SSc is a composite disease of distinctive subsets defined by serum autoantibodies , which have specific clinical and HLA class II associations.