Features of macrophage marker CD68 expression in the colonic mucosa of patients with symptomatic uncomplicated diverticular disease and acute uncomplicated diverticulitis

Abstract

Aim: The aim of the study was to determine the features of macrophage marker CD68 expression in the colonic mucosa of patients with symptomatic uncomplicated diverticular disease and acute uncomplicated diverticulitis. Materials and Methods: The study material comprised colonic mucosal biopsies obtained from 12 healthy individuals (group 1), biopsies of the colonic mucosa from the diverticular orifice region of 34 patients with symptomatic uncomplicated diverticular disease (group 2), and 26 patients with acute uncomplicated diverticulitis (group 3). Immunohistochemical study was performed using a monoclonal antibody to CD68. CD68 expression was assessed by counting the absolute number of immunopositive cells in the field of view of the microscope ×400. In immunopositive cells, the degree of expression of the monoclonal antibody to CD68 was assessed by determining the brightness coefficient. Results: Comparative analysis of the obtained results revealed an increased number of macrophages in the colonic mucosa of patients with symptomatic uncomplicated diverticular disease and acute uncomplicated diverticulitis, with the greatest increase observed in acute uncomplicated diverticulitis. The brightness coefficient decreased in patients with symptomatic uncomplicated diverticular disease and, more markedly, in acute uncomplicated diverticulitis, indicating increased expression of the studied monoclonal antibody by macrophages. In these patients, macrophages acquired elongated and irregular shapes and increased in size. Conclusions: The mucous membrane of the colon in patients with symptomatic uncomplicated diverticular disease and acute uncomplicated diverticulitis is characterized by a higher content of macrophages, mainly in the lamina propria, which are characterized by increased morphofunctional activity. The latter manifests itself in increased expression of the monoclonal antibody to CD68 by macrophages, an increase in the size of CD68+-cells, and their acquisition of an elongated or irregular shape. The quantitative and qualitative changes in macrophages in the colonic mucosa identified by the authors are more pronounced in patients with acute uncomplicated diverticulitis compared to patients with symptomatic uncomplicated diverticular disease.