Cholesterol saturation rather than phospholipid/bile salt ratio or protein content affects crystallization sequences in human gallbladder bile.
BACKGROUND
In model biles, cholesterol crystallization (an important factor in gallstone formation) mainly depends on phospholipid/bile salt ratios with characteristic sequences of plate-like (monohydrate) vs. non-plate-like (presumed anhydrous: arcs, needles, tubules, spirals) cholesterol crystals. We now investigate whether the same phenomenon occurs in human bile.


METHODS
Appearances of plate-like and non-plate-like cholesterol crystals were determined in filtered bile of 80 cholesterol gallstone patients, and related to biliary lipid and pro-nucleating protein composition.


RESULTS
Non-plate-like crystals appeared before plate-like crystals in 9 biles, on the same day in 24 biles, and after plate-like crystals in 31 biles. In 16 biles only plate-like crystals were observed. Crystal sequences did not depend on biliary lipid or protein composition. Cholesterol saturation indexes were higher in biles with than without non-plate-like crystals (150 +/- 6 vs. 125 +/- 12, P = 0.02). In contrast, phospholipid/(bile salt + phospholipid) ratios, bile salt species, phospholipid classes, concentrations of mucin, IgG, IgM, IgA, haptoglobin and alpha-1 acid glycoprotein did not differ.


CONCLUSIONS
Cholesterol crystallization sequences in human bile depend on cholesterol saturation index rather than on phospholipid/bile salt ratio.
University Medical Center Utrecht, the Netherlands.
N G
NG
Venneman
P
P
Portincasa
G P
GP
Vanberge-Henegouwen
K J
KJ
van Erpecum
D001646:Bile / Q000737:chemistry*; D001647:Bile Acids and Salts / Q000032:analysis*; D002784:Cholesterol / Q000737:chemistry / Q000378:metabolism*; D003460:Crystallization; D005704:Gallbladder / Q000378:metabolism*; D006801:Humans; D010743:Phospholipids / Q000032:analysis*; D011506:Proteins
D001647:Bile Acids and Salts; D010743:Phospholipids; D011506:Proteins; D002784:Cholesterol