Update on Pathogenesis of Opisthorchiasis and Cholangiocarcinoma

Functional activity of blood phagocytes in opistorchiasis patients

Introduction. The urgency of the problem of opistorchiasis is dictated by the long clinical course of the disease with the possibility of formation of hepatobiliary pathology, including cancer. Aim. To study the peculiarities of the production of active oxygen forms of blood phagocytes in patients with opistorchiasis. Material and methods. A total of 42 patients with chronic opisthorchiasis (22 men and 20 women) and 35 apparently healthy patients (18 men and 17 women) between the ages of 24 and 45 were examined. Opistorchiasis was diagnosed by three methods: microscopic examination of duodenal bile, coproovoscopy and serological method. The control group was composed of healthy individuals who underwent routine medical examinations, which included biochemical blood tests, identification of markers for viral hepatitis and antibodies to opistorchs. The culture of neutrophils and blood monocytes was isolated by fractionation of cells on the ficoll with subsequent cleaning from adhering cells. Functional activity of neutrophils and blood monocytes was estimated by chemiluminescence method on production of active oxygen species: basic and after induction with zymosan. Results. In patients with opistorchiasis in comparison with healthy people, in neutrophil granulocytes, the maximum intensity of active oxygen species production decreased and the time to reach the maximum of active oxygen species production was increased both in spontaneous and zymosan-induced reactions in luminoland lucigenin-dependent processes. In monocytes during spontaneous reaction study it was discovered that the maximum intensity of oxygen production in luminoland lucigenindependent processes decreased and the time of reaching the maximum of oxygen production in luminol-dependent process increased in opistorchiasis patients in comparison with healthy people. When studying the zymosan-induced reaction in monocytes, a decrease in the maximum intensity of active oxygen species production in both reactions and an increase in the time to reach the maximum output of active oxygen species in the luminol-dependent process was registered in patients with opistorchiasis in comparison with healthy people. Conclusion. The data obtained indicate low functional activity of blood phagocytes in patients with chronic opistorchiasis in comparison with healthy people.

Opisthorchis felineus infection provokes time-dependent accumulation of oxidative hepatobiliary lesions in the injured hamster liver

Opisthorchiasis caused by food-borne trematode Opisthorchis felineus is a substantial public health problem, with 17 million persons infected worldwide. This chronic disease is associated with hepatobiliary inflammation, cholangiocyte dysplasia, cholangiofibrosis, intraepithelial neoplasia, and even cholangiocarcinoma among chronically infected individuals. To provide first insights into the mechanism by which O. felineus infection causes precancerous liver lesions, we investigated the level of oxidative stress (lipid peroxidation byproducts and 8-hydroxy-2′-deoxyguanosine) as well as the time course profiles of chronic inflammation and fibrogenesis markers in the dynamics of opisthorchiasis from 1 month to 1.5 years postinfection in an experimental model based on golden hamsters Mesocricetus auratus. For the first time, we showed that O. felineus infection provokes time-dependent accumulation of oxidative hepatobiliary lesions in the injured liver of hamsters. In particular, over the course of infection, lipid peroxidation byproducts 4-hydroxynonenal and malondialdehyde were upregulated; these changes in general correlate with the dynamics of hepatic histopathological changes. We detected macrophages with various immunophenotypes and elevated levels of CD68, COX2, and CD163 in the O. felineus–infected animals. Meanwhile, there was direct time-dependent elevation of TNF-α (R = 0.79; p < 0.001) and CD163 protein levels (R = 0.58; p = 0.022). We also provide quantitative data about epithelial hyperplasia marker CK7 and a marker of myofibroblast activation (α smooth muscle actin). Our present data provide first insights into the histopathological mechanism by which O. felineus infection causes liver injuries. These findings support the inclusion of O. felineus in Group 1 of biological carcinogens.