Morphological features of the intestinal mucosa in ulcerative colitis in various forms of the disease
Authors: Gaydar Yu.A. , Stoikevich M.V. , Mylostуva D.F. , Tarasova T.S. 
Published: June 2022

Background. Chronic inflammatory bowel disease (CIBD) is one of the most complex nosological groups in gastroenterology, due to the constant increase in their prevalence, shifting the onset to an earlier age, increasing the frequency of severe complicated forms. The most common representative of CIBD is nonspecific ulcerative colitis (UC). At the heart of UC is a diffuse ulcerative-inflammatory lesion of the colon. The leading role in the diagnosis of UC belongs to the comparison of the results of endoscopic and morphological methods of research. The morphological method of colonobiopsy examination in UC is the gold standard of diagnosis and makes it possible to determine the signs of disease activity even in endoscopic remission. In contrast to descriptive histology, pathological anatomy, quantitative morphology complements and clarifies the data of studies conducted by conventional morphological methods from the standpoint of generalized approaches. The purpose of quantitative morphology is the maximum objectification of the study of qualitative and quantitative manifestations of pathological processes, nosological units, their pathogenesis, morphogenesis, as well as the exclusion of measurement errors and, as far as possible, the subjectivity of the researcher. The purpose of the study: to conduct a comparative histological examination of biopsies of the mucous membrane of the colon in patients with UC of different severity of the disease. Materials and methods. Histological examination of intestinal biopsy specimens was performed in 55 patients with ulcerative colitis. Patients were divided according to the severity of the disease. Group I (n=11)— mild form, group II (n=39)— moderate form and group III (n=5)— patients with severe UC. Results. In 63.6% with a mild severity of UC edema was not observed, the condition of the epithelium was unchanged, the architecture is not disturbed. Crypt abscesses were detected in 54.6% of cases, atrophic changes— in 90.9%. Inflammatory infiltrate consisted mainly of neutrophils ((176.0±8.22) per 1 mm2 stroma) and mononuclear cells ((232.4±22.83) per 1 mm2 stroma), which indicates the activation of regenerative functions of the mucous membrane. From morphometric measurements the highest indicator was the height of the crypt epithelium (38.3±1.49) μm. With an moderate degree of UC in 33.3% of cases there was a violation of the integrity of the epithelium, atrophic changes were diagnosed in 23.1% of cases, violations of crypt architecture— in 17.9%, the presence of crypt abscesses— 48.8%, edema— 64.1%. Morphometric measurement of intestinal mucosal biopsies with moderate severity of UC showed the highest crypt depth (452.6±8.12) μm, crypt epithelial height (42.3±0.33) μm and the number of goblet cells (26.6±1.43). The height of the crypt epithelium was positively correlated with the number of goblet cells (r=0.30; p <0.05). Erosions, general epithelial disorders, crypt abscesses, and atrophic changes were observed in the majority of patients with severe UC in 40%. In severe UC, the smallest crypt depth (426.1±22.37) μm, crypt epithelial height (36.0±2.57)μm, the number of goblet cells (10.5±1.04) and the largest epithelial thickness were observed (51.5±2.81) μm. Conclusions. The presence of crypt abscesses was mainly observed in the group of mild and moderate forms of the disease. Mucosal edema was more common in the group with moderate severity disease. Increased numbers of eosinophils and neutrophils were observed in the group with severety disease.