Z Gastroenterol 2008; 46 - P5_23
DOI: 10.1055/s-2008-1037672

ABCB4 and ABCB11 polymorphisms and plasma lipid levels. A study in affected sib pairs with gallstones and controls

M Acalovschi 1, S Tirziu 2, E Chiorean 1, F Grünhage 3, F Lammert 4
  • 13rd Medical Clinic, University Iuliu Hatieganu, Cluj-Napoca, Rumanien
  • 23rd Medical Clinic, University Iuliu Hatieganu, Cluj-Napoca, Rumanien
  • 3Medizinische Klinik und Poliklinik I, Universität Bonn, Bonn
  • 4Medizinische Klinik I, Universität Bonn, Bonn

Aim. To analyze the plasma lipid levels in carriers of polymorphisms of ABCB11 (the gene encoding the bile salt export pump) and ABCB4 (the gene encoding the phospholipid transporter across the canalicular membrane of the hepatocyte). The two genes have been designated as candidate genes for gallstone development in mice.

Method. Plasma triglyceride, cholesterol and HDL-cholesterol levels were measured after a 12-hour fast in 108 patients with gallstones and gallstone heredity (i.e. the index patients of 108 sib pairs with gallstones), and in 260 controls matched for gender and age. Using PCR-based assays with 5'-nuclease and fluorescence detection (TaqMan), the ABCB11 coding SNP p.A444V and four haplotype-tagging SNPs covering the ABCB4 gene (c.504C>T, c.711T>A, p.R652G, rs31653 in intron 26) were genotyped. The plasma lipid values were analyzed in carriers of the common allele versus carriers (hetero-/homozygote) of the rare allele of these polymorphisms using Student t tests and Pearson correlation coefficients.

Results. Patients and controls were of similar age. We found significant differences between the index patients of the sib pairs and the controls with regard to BMI and plasma lipid levels: triglyceride levels were higher (p<0.001), HDL-cholesterol (p<0.001) and cholesterol (p<0.02) levels were lower in siblings with gallstones. No correlation was detected between BMI and triglyceride levels in patients with gallstones. When analyzing the plasma lipid profile for each polymorphism, we found the following significant differences in the subjects with gallstones: higher triglyceride and cholesterol levels in carriers of the common ABCB11 allele, lower HDL-cholesterol concentrations in carriers of the common allele of SNP rs31653. Differences were also detected in controls with regard to cholesterol levels (two ABCB4 polymorphisms) and HDL-cholesterol concentrations (one ABCB4 polymorphism).

Conclusion. Our results do not support the hypothesis of a link between ABCB4 and ABCB11 polymorphisms, lithogenic dyslipidemia and gallstone risk.

ABCB11 - ABCB4 - gallstones - plasma lipids - polymorphism