Relationship between autoimmune hepatitis and HLA-DR4 and DR®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 amplification with sequence-specific primers (PCR-SSP) was performed to examine 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 increased frequency among patients with AIH versus healthy control (46.9% versus 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 addition, a significant increase was found in the alleles frequency encoding QRRAA 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 relationship between QRRAA sequence within the third hyperpolymorphic region of the DRB allele and AIH in Chinese.