Abstract: Objective To explore HLA-DQA1 and DQB1 alleles in their association with genetic susceptibility to psoriasis vulgaris(PV) in Han Chinese. Method Polymerase chain reaction sequence specific primers (PCR-SSP) method was used to analyze the frequencies of HLA-DQA1 and DQB1 alleles among 189 patients with PV and 273 healthy controls. Results ①HLA-DQA1*0104 and DQA1*0201 alleles were positively associated with PV (Pc<0.05); HLA-DQA1*0501 allele was negatively associated with PV(Pc<0.001). ②HLA-DQA1*0104, DQA1*0201 and DAQ1*0501 alleles were associated with typeⅠpsoriasis only. ③HLA-DQA1*0104 and DQA1*0201 alleles were increased in patients with or without family history. DQA1*0501 allele was only decreased in patients without family history. Conclusions ①HLA-DQA1*0104 and DQA1*0201 alleles may be the susceptible genes or have close linkage with susceptible genes. HLA-DQA1*0501 allele may have protective effects on development of PV in the Chinese. ②There may be a difference in genetic background between psoriasis patients with and without family history.

Key words: Alleles, Psoriasis, HLA-DQ antigens