Pancreatic pathomorphology in superinvasive opisthorchiasis

Superinvasive opisthorchiasis involves many body systems in the pathological process. The parasite, due to its unique characteristics, changes numerous genes, and contributes to proliferative processes. Stem cells are initiated and subsequently differentiated along various cell lineages. The liver and pancreas are econiches, where parasites vegetate for a long time. However, there is no available information on the dynamics of proliferative pancreatic changes and various histogenetic pathways. The aim of the paper is to reveal the proliferative activity of pancreatic stem cells in superinvasive opisthorchiasis and their differentiation. Materials and Methods. Fragments of pancreatic tissue were selected and analyzed in departments of morbid anatomy of medical institutions located on the territory of the hyperendemic focus (Tyumen region, Omsk region, Khanty-Mansiysk Autonomous Okrug). The following groups were formed: Group 1 -patients with a history of superinvasive opisthorchiasis with a more than 10-year invasion (n=70); Group 2 - patients without invasion with all-cause mortality (n=10). The material was subjected to routine histological examination. The authors used histochemical and immunohistochemical staining methods and performed statistical analysis. Results. The authors observed marked proliferative reactions in the epithelial layer of the duct system, the secretory section of the pancreas, as well as changes in the endocrine apparatus. The histological types of pancreatic endocrine formations were revealed, namely, normal, hyperplastic and newly formed islets of Langerhans. The difference between the newly formed islets and the preexisting forms was in a disorderly arrangement, an indefinite shape, significantly larger sizes, and in the absence or presence of a forming capsule. The newly formed islets contained cells similar to preexisting endocrinocytes. Conclusion. Under the influence of the Opisthorchis felineus secretome, there occurs initiation and differentiation of pancreatic stem cells. Newly formed clusters of endocrine cells are formed, but they have the characteristics of the preexisting endocrine apparatus and secretory cells with exocrine properties.