Relationship between autoimmune hepatitis and HLA-DR4 and DR beta allelic sequences in the third hypervariable region in Chinese

AIM To analyze the association of HLA-DRB1 with autoimmune hepatitis (AIH) in patients from China. METHODS In 32 patients and 48 healthy controls, polymerase chain reaction a mplification with sequence-specific primers (PCR-SSP) was performed to exam ine the association of certain alleles or polymorphic sequences of HLA-DRB1 with AIH. RESULTS HLA-DRB1 typing by PCR-SSP showed that DR4 had a significantly incr eased frequency among patients with AIH versus healthy control (46.9% versu s 20.8%; relative risk = 3.35, P = 0.014). In subtypes of DR4, there was a trend of increase in the gene frequency of DRB1* 0405 in patients with AIH versus healthy controls (21.9% vs 6.3%, P = 0.04, but P-c = 0.08). In addit ion, a significant increase was found in the alleles frequency encoding QRR AA from the third hyperpolymorphic region of DR4 in the patients with AIH ( 86.7% of DR4 positive patients vs 40.0% in DR4 positive controls, P = 0.016 , P-c = 0.028, RR = 9.75). CONCLUSION AIH in Chinese is associated with HLA-DR4. There is a relationsh ip between QRRAA sequence within the third hyperpolymorphic region of the D RB allele and AIH in Chinese.