Concanavalin A-binding cholesterol crystallization inhibiting and promoting activity in bile from patients with Crohn's disease compared to patients with ulcerative colitis

Background/Aims: Crohn's disease is a risk factor for gallstone formation. In contrast, patients with ulcerative colitis have an incidence of gallston e formation comparable to the general population. The reason for this diffe rence is not known. The aim of this study was to elucidate the factors cont rolling cholesterol crystallization in gallbladder bile of Crohn's disease and ulcerative colitis patients. Methods: Gallbladder bile was obtained by aspiration during bowel resection s (26 Crohn's disease patients, 20 ulcerative colitis patients). Biliary li pid composition, crystal detection time and the effect of extraction of the concanavalin A-binding fraction on crystal formation were determined. Results: Cholesterol crystals were present in seven of the 26 bile samples of Crohn's disease-patients and one of the 20 ulcerative colitis patients. Four of the bile samples of Crohn's disease patients were fast nucleating. None of the 20 ulcerative colitis patients had fast nucleating bile. Lipid composition, total lipid concentration and CSI were not significantly diffe rent between the two groups. In Crohn's disease patients extraction of conc anavalin A-binding fraction decreased crystallization in 10 bile samples bu t accelerated crystallization in one bile sample. In eight bile samples fro m ulcerative colitis patients crystallization increased after concanavalin A-binding fraction extraction. Conclusions: Compared to ulcerative colitis patients, gallbladder bile of C rohn's disease patients showed increased cholesterol crystallization despit e comparable lipid composition and cholesterol saturation index. This diffe rence is caused by increased cholesterol crystallization-promoting activity . Bile from ulcerative colitis patients contains a Con A-binding factor whi ch inhibits cholesterol crystallization.