Characteristics of pathomorphological and immunohistochemical changes of the tissue of the pantacric gland in patients with chronic pancreatitis

Abstract

Introduction. Chronic pancreatitis (CP) is a inflammatory disorder of the pancreas with subsequent progressive irreversible morphological changes, such as the replacement healthy parenchyma of the pancreas by fibrous tissue. That is why one of the leading pathomorphological signs in CP is fibrosis, which has a staged and permanent character due to the activation of fibroblasts, the transformation of contractile myofibroblasts into secretory myofibroblasts with subsequent disruption of stromal-epithelial cell interaction. The key role of various cellular components of the connective tissue in the structural reorganization of the pancreatic parenchyma has not yet been fully established. The aim of the study was histo- and immunohistochemical evaluation of the quantitative composition of connective tissue elements in patients with chronic pancreatitis with varying degrees of fibrosis. Materials and methods. The degree of pancreatic fibrosis in our study was evaluated according to Stolt (1987). Histological material was studied with its fixation in a 10% solution of neutral formalin which helped to assess morphological changes in the pancreas. Preparations were prepared according to the standard method, histological sections with a thickness of 5–7 μm were stained with hematoxylin and eosin, van Gieson's picrofuchsin, Masson's trichrome. Immunohistochemical studies were performed by the indirect immunoperoxidase method with primary antibodies and the DAKO EnVision + imaging system with diamine benzidine (DAKO, Denmark) according to standardized protocols for paraffin sections. Research results and their discussion. The morphological picture of chronic pancreatitis was characterized by deformation of the ductal system, nerve trunks and vessels against the background of fibrosis with significant tortuosity and ductal expansion due to periductal fibrosis with expansion of interlobular fibrous septa, thickening of intralobular connective tissue cords, structural rearrangement (remodulation) with dissociation , disorganization and disintegration of collagen bundles. Diffuse interlobular fibrosis, which covered most of the lobules of the pancreas, was usually combined with intralobular septal-periacinar fibrosis of the pancreas, which was characterized by the presence of fibrous septa of different thicknesses in the lobules, as well as areas of concentric periacinar fibrosis. Conclusions. The perspective of deep analysis and understanding of the processes of stimulation of collagenogenesis and biodegradation in patients with chronic pancreatitis can have a significant impact on the development of new methods of operative and conservative correction of the disease.