Association between morphological manifestations of inflammatory bowel disease and biochemical markers of inflammation

Aim. To determine morphological and morphometric changes in the structure of the mucous membrane of the large intestine and their relationship with the content of short-chain volatile fatty acids and fecal calprotectin in patients with inflammatory bowel disease. Materials and methods. We examined 68 patients with inflammatory bowel disease, including 30 women and 38 men aged 20–66 years, 55 patients were with ulcerative colitis and 13 patients – with Crohn’s disease. Histological examination focused on changes in the mucous membrane of the large intestine. Determination of short-chain volatile fatty acids in feces was performed using gas chromatography. Calprotectin content was measured in fecal samples by enzyme-linked immunosorbent assay. Results. Significant correlations were found between epithelial disruption and changes in crypt architecture, infiltration density, and histological activity. The higher degree of inflammation in patients with severe course was combined with a lower level of tissue nonspecific protection, which was detected by the number of goblet cells, eosinophilic and neutrophilic leukocytes. There was a decrease in the fecal concentration of butyric acid in patients with nonspecific ulcerative colitis and Crohn’s disease compared with controls, but a more significant decrease was observed in patients with severe nonspecific ulcerative colitis. The data have confirmed the association between inflammatory bowel disease and the content of short-chain volatile fatty acids, fecal calprotectin in coprofiltrate, which was evidenced by the presence of correlations between low content of short-chain volatile fatty acids and eosinophilic infiltration (r = -0.412; fecal calprotectin levels and disease severity (r = 0.589; P = 0.001), atrophy (r = 0.458; Р < 0.05), infiltration density (r = 0.434; Р < 0.05). Conclusions. All patients with inflammatory bowel disease are characterized by a specific histological picture, which reflected the different degrees of inflammation. Morphometric parameters more accurately show significant atrophic changes in the mucous membrane of the large intestine. The data have confirmed the association between inflammatory bowel disease and the content of short-chain volatile fatty acids and calprotectin in coprofiltrate.