Objective: To study the relationship between human leukocyte antigen-DRB1 (HLA-DRB1) allele genes polymorphism and intrahepatic cholestasis of pregnancy (ICP).
Methods: Forty-two patients with ICP were tested for HLA-DRB1 allele genes polymorphism with the polymerase chain reaction technique and sequence specific oligonucleotide (PCR-SSO) probes hybridization, 56 normal pregnant women as control group were also tested. In addition, the phenotype frequencies of HLA-DRB1 alleles were compared with it's clinical character in patients with ICP.
Results: The higher frequencies were observed for alleles DR9, DR12 and DR4 in both groups. DR6 alleles were detected in 14 cases out of 42 patients. Patients with ICP had a significantly higher frequency of the allele DR6 when compared to control group (16.7% vs 3.6%), with a relative risk (RR) as 6.5 (P < 0.01). No significant differences were observed between the frequencies of other detected HLA-DRB1 alleles in both groups. There was no association between HLA-DR6 allele and the level of liver function and cholylglycine in ICP.
Conclusion: The study showed that HLA-DR6 gene might be one of the susceptibility genes to ICP.