The Association between Bile Salt Export Pump Single-Nucleotide Polymorphisms and Primary Biliary Cirrhosis Susceptibility and Ursodeoxycholic Acid Response

BACKGROUND Primary biliary cirrhosis (PBC) is a chronic and progressive cholestasis liver disease. Bile salt export pump (BSEP) is the predominant bile salt efflux system of hepatocytes. BSEP gene has been attached great importance in the susceptibility of PBC and the response rate of ursodeoxycholic acid (UDCA) treatment of PBC patients. METHODS In this study, TaqMan assay was used to genotype four variants of BSEP, and the Barcelona criteria were used for evaluating the response rate of UDCA treatment. RESULTS Variant A allele of BSEP rs473351 (dominant model, OR = 2.063; 95% CI, 1.254-3.393; P = 0.004) was highly associated with PBC susceptibility. On the contrary, variant A allele of BSEP rs2287618 (dominant model, OR = 0.617; 95% CI, 0.411-0.928; P = 0.020) provided a protective role and Barcelona evaluation criterion indicated that the frequency of variant allele at BSEP rs2287618 was significantly decreased in UDCA-responsive PBC patients (P = 0.021). CONCLUSION These results suggested that BSEP rs473351 was closely associated with the susceptibility of PBC and if people with BSEP rs2287618 were diagnosed as PBC, the UDCA treatment was not satisfactory. Larger studies with mixed ethnicity subjects and stratified by clinical and subclinical characteristics are needed to validate our findings.