ENDOTHELIAL DYSFUNCTION AND PLATELET FUNCTION DISORDER IN HEMOSTASIS IN DEVELOPMENT OF HEPATIC FIBROSIS IN CHILDREN WITH AUTOIMMUNE HEPATITIS

Aim. To assess the clinical significance of the endothelial condition and platelet aggregation in the development of hepatic fibrosis in children with autoimmune hepatitis. Materials and Methods. 35 patients aged from 3 to 17 years were studied, including 19 girls (54%) and 16 boys (46%). The 1st group consisted of 17 children with F 0-2 degree of fibrosis acc. to the Metavir score; the 2nd group consisted of 18 children with F 3-4 degree of fibrosis acc. to the Metavir score (based on the indirect elastometry data). In children of the 2nd group hepatic cirrhosis was diagnosed. The control group consisted of 15 children of I or II health group. Concentration of endothelin-1 in blood serum was determined by ELISA method (Endothelin-1 test-system), and of VWF – on hemocoagulation analyzer ACL-TOP 500 (Instrumentation Laboratory Company, USA) using Willebrand factor kit. Quantity of platelets was determined using hematological analyzer Cell-Dyn 610 (Abbott Diagnostics, USA), aggregation capacity of platelets was assessed on platelet aggregation analyzer with use of adenosine phosphate (1.25 mg/mL) and collagen (2.0 mg/mL) as platelet aggregation inducers. Results. In the analyzed sample of children with autoimmune hepatitis ¾ had signs of the various-degree fibrosis formation. Patients of the 2nd group had a more aggressive course as compared to the 1st group: more asthenoneurotic complaints at the onset of disease (p=0.021), manifestations of the jaundice syndrome (p=0.014), more cases of hepatocellular insufficiency (p=0.045), complications of the disease: hypersplenism (p=0.014), varicose veins of the esophagus (p=0.003). All children with autoimmune hepatitis had signs of endothelial dysfunction and of enhanced platelet aggregation activity. The degree of fibrosis correlated with the concentration of endothelin-1 (r=0.4, p=0.004) and with activity of von Willebrand factor (VWF) (r=0.5, p<0.001) and with platelet count (r=-0.5, p=0.003). Conclusions. In children with autoimmune hepatitis the endothelial dysfunction and platelet disorders in the hemostasis system were revealed that correlated with the severity of the pathological process. Determination of endothelin-1 concentration, activity of von Willebrand factor and platelet count may be used to assess severity of liver pathology in children with autoimmune hepatitis.