title: Composition and immunofluorescence studies of biliary "sludge" in patients with cholesterol or mixed gallstones.
abstract: OBJECTIVE
  Gallbladder bile from patients with cholesterol or mixed gallstones frequently contains biliary "sludge", a suspension of cholesterol monohydrate crystals and pigment granules embedded in mucin and proteins. The composition of biliary "sludge" and the preferential localization of mucin and proteins could be an indicator for its potential role in gallstone formation.
  
  
  METHODS
  Ultracentrifugation (100000 g/l h) was used to precipitate "sludge" from bile, and the concentration difference of its main components between native bile and ultracentrifuged bile samples was calculated. After purification of the sediment, immunolocalization was performed for the detection of mucin, IgA, albumin, aminopeptidase, and anionic polypeptide fraction using polyclonal and monoclonal antibodies.
  
  
  RESULTS
  The amount of sludge in gallbladder bile was 4.26 mg/ml-0.78 (mean+/-SEM) in patients with cholesterol and 2.51 mg/ml+/-0.39 in patients with mixed stones and cholesterol was the main component (48.9+/-4.6% and 44.4+/-7.1%). The sediment appeared as a mixture of vesicular aggregates and pigment particles which were linked by a gel matrix of mucin containing cholesterol crystals. While anionic polypeptide fraction and aminopeptidase were associated to pigments, IgA was uniformly spread in the crystalline parts of "core-like" structures, and albumin, when it was present, appeared as randomly located small spots.
  
  
  CONCLUSIONS
  Our study demonstrates that the cholesterol content and the distribution pattern of mucin and different proteins is similar in the sediments of biliary "sludge" to that previously shown in cholesterol and mixed gallstones. This suggests that biliary "sludge" represents an early stage of gallstone formation in these patients.
authors.affiliation: INSERM Unite 476, Nutrition Humaine et Lipides, Marseille, France.
authors.forename: P L
authors.initials: PL
authors.lastname: de la Porte
authors.forename: H
authors.initials: H
authors.lastname: Lafont
authors.forename: N
authors.initials: N
authors.lastname: Domingo
authors.forename: G
authors.initials: G
authors.lastname: Meyer
authors.forename: I
authors.initials: I
authors.lastname: Müller
authors.forename: B
authors.initials: B
authors.lastname: Zündt
authors.forename: D
authors.initials: D
authors.lastname: Jüngst
mesh_terms: D001059:Apoproteins / Q000032:analysis; D001646:Bile / Q000737:chemistry*; D018826:CD13 Antigens / Q000032:analysis; D002135:Calcium-Binding Proteins / Q000032:analysis; D002769:Cholelithiasis / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism*; D005260:Female; D006801:Humans; D007158:Immunologic Techniques; D008297:Male; D009077:Mucins / Q000032:analysis
chemical_list: D001059:Apoproteins; D002135:Calcium-Binding Proteins; D009077:Mucins; C489588:anionic polypeptide fraction, human; D002784:Cholesterol; D018826:CD13 Antigens