Features of immune status in children with Wilson–Konovalov disease at different stages of liver fibrosis

The pathology in WilsonConovalov disease (WCD) results from impaired excretion of copper, thus leading to its excessive accumulation in tissues. Hypercupreniluria is characteristic to the WCD. Toxic effects of copper on liver tissue can manifest as fatty degeneration of hepatocytes, hepatitis, fibrosis and cirrhosis. Purpose of the present work was as follows: estimation of immune status in children with WD depending on the stage of liver fibrosis. Fifty-three patients with WCD aged 6 to 18 years, were examined. The stage of liver fibrosis was assessed by transient liver elastography using FibroScan F502 (EchoSence, France). The immune status of peripheral blood lymphocytes was examined using CYTOMICS FC500 flow cytofluorimeter (Beckman Coulter, USA). The relative numbers of B lymphocytes (B1 and B2 populations), NK cells, T helper cells, cytotoxic T lymphocytes, Th17 lymphocytes, regulatory T cells, activated T helper cells were assessed in the lymphoid area. All indices of the patients immune status were recalculated for percentage of deviation from the age-dependent reference values. Mass concentration of copper in daily urine was determined by atomic absorption method using AAnalyst 800 spectrometer. Statistical processing was performed by Statistica10.0 program. The WCD patients are characterized by an increase of Т helpers, regulatory Т cells, Th17 lymphocytes and activated Т helpers, along with decrease of cytotoxic Т lymphocytes and NK cells against normal levels. The number of B cells did not depend on the stage of liver fibrosis and was at the lower limit of normal range, or decreased. Upon increase of the liver fibrosis stage, the number of B1 lymphocytes increases and B2 lymphocytes become decreased. The urinary copper content in the examined patients varied from 19 to 835 g/day, being higher than the reference values in 88% of children, with median value of 175 g/day (71-330). A correlation between urinary copper concentration and degree of immune status deviation was revealed (R = 0.63): urinary copper concentration was increased when the number of Th17 lymphocytes, B1 lymphocytes and regulatory T cells became higher, and when the number of B2 lymphocytes decreased. A significant decrease in the population of cytotoxic T lymphocytes (p = 0.034) was observed in children with WCD in the presence of KaiserFleischer ring. Indexes of cellular immunity in children with WCD are an informative tool to assess the severity of liver damage.