title: Biliary pronucleating proteins and apolipoprotein E in cholesterol and pigment stone patients.
abstract: OBJECTIVE
  Although cholesterol gallstone patients exhibit higher biliary cholesterol saturation than pigment stone patients, underlying mechanisms that affect stone type are unknown. We hypothesized that pronucleating proteins, hydrophobic bile salts or apolipoprotein E genotype affect stone type. We therefore compared these putative factors in cholesterol and pigment stone patients.
  
  
  METHODS
  In 74 cholesterol and 12 pigment stone patients, bile lipids, various pronucleating proteins, crystallization and apolipoprotein E genotype were determined.
  
  
  RESULTS
  Crystallization was enhanced, and cholesterol saturation higher in case of cholesterol stones, without any difference in bile salt composition. Concentrations of mucin (0.91+/-0.08 versus 0.31+/-0.06 mg/ml: P<0.0001), protein, IgM, IgG, IgA, haptoglobin, alpha1-acid glycoprotein and haptoglobin were 2-6-fold higher in cholesterol stone patients. Twenty cholesterol stone pts (27%) but only one pigment stone pt (8%) had at least one epsilon4 allele. There was a significant difference in allele frequencies between both groups (cholesterol stones similar to Dutch population: epsilon2 0.074, epsilon3 0.770, epsilon4 0.156: pigment stones: epsilon2 0.250, epsilon3 0.708, epsilon4 0.042).
  
  
  CONCLUSIONS
  Various pronucleating biliary proteins are markedly higher in cholesterol than pigment stone patients. Also, apolipoprotein E genotype differs between cholesterol and pigment stone patients. These factors may affect gallstone type.
authors.affiliation: Department of Gastroenterology, University Hospital Utrecht, Postbox 85500, 3508 GA Utrecht, The Netherlands. k.j.vanerpecum@azu.nl
authors.forename: Karel J
authors.initials: KJ
authors.lastname: van Erpecum
authors.forename: Piero
authors.initials: P
authors.lastname: Portincasa
authors.forename: Mehmet H
authors.initials: MH
authors.lastname: Dohlu
authors.forename: Gerard P
authors.initials: GP
authors.lastname: van Berge-Henegouwen
authors.forename: Dieter
authors.initials: D
authors.lastname: Jüngst
mesh_terms: D000328:Adult; D001057:Apolipoproteins E / Q000235:genetics*; D001646:Bile / Q000737:chemistry; D001647:Bile Acids and Salts / Q000737:chemistry; D002784:Cholesterol / Q000032:analysis / Q000737:chemistry*; D003460:Crystallization; D005260:Female; D042882:Gallstones / Q000737:chemistry* / Q000235:genetics*; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009077:Mucins / Q000737:chemistry; D010860:Pigments, Biological / Q000032:analysis / Q000737:chemistry*
chemical_list: D001057:Apolipoproteins E; D001647:Bile Acids and Salts; D009077:Mucins; D010860:Pigments, Biological; D002784:Cholesterol