Immunological abnormalities in children with biliary atresia

Since orthotopic liver transplantation is the treatment of choice for bilary atresia, the role of nutritional support preceding this procedure is significant. The aim of this study was to assess the selected parameters of both humoral and cellular immunity before and after nutritional support. Eight children aged 1.08-7 years. with biliary atresia, qualified to LTx, received high-calorie standard diet supplemented with MCT oil. The distribution of functionally different lymphocyte subpopulations in the peripheral blood was evaluated using double color flow cytometry (EPICS-MCL, Coulter). The concentrations of total serum immunoglobulins were measured by nephelometry (Beckman Array 360) and concentrations of IgG subclasses by ELISA. Abnormalities in the expression of lymphocyte surface markers as well as in immunoglobulin synthesis were as follows: 1) decrease in the percentage of total CD3+ (4/8), CD4+ (5/8), CD8+ (3/8) cells and markedly elevated percentage of CD19+ B cells (4/8); 2) reduction of the proportion of 'naive' CD4+ and CD8+ lymphocytes but normal percentage of 'memory' CD4+ and CD8+ cell subsets; 3) hypergammaglobulinemia with especially high levels of IgG (16.0-3.05 g/l) and IgA (2.6-6.66 g/l) was found in 6 out of 8 children. Treatment with hypercaloric diet did not improve the immunological parameters. We conclude that lymphopenia and possibly also hypergammaglobulinemia observed in BA children resulted mainly from the deficiency of the so-called 'naive', suppressor-inducer CD4+ T cell subset (CD4+/CD45RA+) that is known to maintain the proper level of immunoglobulin synthesis by inhibition of B cell differentiation into plasma cells.