The dissertation studies the features of functional state of hepatobiliary system and development prognosis thereof in children with inflammatory bowel diseases. The features of functional state of hepatobiliary system in children with Crohn's disease and ulcerative colitis were researched depending on the activity, illness duration and type of therapy, features of lipid metabolism disorder, intestinal microbiotics, polymorphism of detoxification genes, hepatobiliary system structural-functional condition and stiffness of liver parenchyma. It was found that 45% of children with CD and 45,3% of children with UC suffered from liver functional state disorder. A correlation was identified between the indicators of cytolytic and immune-inflammatory syndromes with CD activity (χ 2 = 20.00; p <0.001), as well as between the indicators of cytolysis, cholestasis and immune-inflammatory syndrome with activity and spread of colitis and type of therapy in children with UC (р <0,05). Chronic liver diseases (primary sclerosing cholangitis, autoimmune hepatitis, granulomatous hepatitis, cholelithiasis, non-alcoholic steatohepatitis) were present in 8,5% of children with UC. In 72.5% of patients with CD and 63.75% of patients with UC, a lipid metabolism disorder was present due to increased levels of LDL, atherogenity and HDL level reduction. In patients with CD and UC, fatty acid spectrum disorder was present in the form of increase of NLC in blood plasma and of PFA in erythrocyte membranes (predominantly ω-6) (p <0,05). In all examined children with СD and UC, a microbiotoxicity disorder was detected in form of decrease in the amount of Bifidobacterium, Lactobacillus, and a relationship between increased levels of transaminases and decreased levels of Bifidobacterium <6 log and Lactobacillus <5 log (χ 2 = 5.0; p <0.05) was established. A correlation between liver functional state disorder (increased level of transaminases) with the non-functional TT-genotype of phase III detoxification gene MDR1 (C3435T) is proved (χ 2 = 5.71; p = 0.02). IBD in children leads to increased stiffness of liver parenchyma in 50% of children with UC and 37.7% of children with CD. A direct correlation of stiffness indices of liver parenchyma with activity of the disease (PCDAI) – τ = 0.4 (p = 0.02), faecal calprotectin – τ = 0.54 (p = 0.01) and thymol test – τ = 0.3 (p = 0.05) in children with CD, as well as with ALT (τ = 0.37, p = 0.03), GGT (τ = 0.25, p = 0.04) and AST (τ = 0.24, p = 0.04) in children with UC was established. An algorithm for early diagnosis and monitoring of hepatobiliary system functional state disorders in children with CD and UC was developed.
