Risk of gallstone disease in advanced chronic phase of fascioliasis: an experimental study in a rat model.

In Wistar rats experimentally infected with Fasciola hepatica, the association between time of infection, number of flukes, rat weight, and serum lipid levels and the risk of developing pigment stones in the main bile duct was examined using data obtained at 100, 200, 300, 400, and 500 days postinfection. Gallstone presence increased with infection time. The relative risk of gallstone disease increased when the number of flukes per rat and rat weight increased. The presence of gallstones was associated with serum high-density lipoproteins and triglyceride levels. In a multivariate analysis, the association between gallstones and rat weight disappeared after adjustment for serum lipids. The absence of an effect of rat weight independent from serum lipids suggests that serum lipids are more closely linked to gallstone pathogenesis than is overweight. The presence of gallstones was strongly associated with the number of flukes located in the bile duct. A high risk of developing gallstones may be expected in human subjects inhabiting areas where F. hepatica is highly endemic and where high egg outputs detected in humans suggest that liver fluke burdens may also be very high.