Age-related changes in the parameters of cellular immunity, the activity of intracellular lymphocyte dehydrogenases and functional activity of neutrophils in children with Gaucher disease

   Gaucher disease (GD) is an autosomal recessively inherited disease that belongs to the group of lysosomal storage diseases. In GD, there is chronic activation of the macrophage system, disruption of the regulatory functions of macrophages, a shift in cytokine regulation towards pro-inflammatory cytokines and the development of chronic inflammation involving all immune cells, which can lead to changes in the composition of both major and minor populations of lymphocytes. Reduced beta-glucocerebrosidase activity impairs normal lysosomal function and autophagy, leading to the intracellular accumulation of glycosphingolipids, creating a self-sustaining cycle of impaired glucocerebroside utilization with the aggravation of both lysosomal and mitochondrial functions. It is known that untreated patients with GD are susceptible to more frequent and complicated infectious diseases, which presumably may arise due to changes in the functional activity of neutrophils caused by the disruption of the process of phagocytosis and oxidative burst in this cell population.

   The aim: to study the age-related features of the composition of the major and minor populations of peripheral blood lymphocytes, the activity of intracellular dehydrogenases of lymphocytes and the functional activity of neutrophils in children with GD.

   The study was approved by the Independent Ethics Committee and the Scientific Council of the National Medical Research Center for Children's Health of Ministry of Healthcare of the Russian Federation. The study included 73 children with GD, of which 26 children were examined at different age periods (1 child – 4 tests, 3 children – 3 tests, 22 children – 2 tests), the comparison group consisted of 148 healthy children comparable in age. The determination of the subpopulation composition of lymphocytes, the study of succinate dehydrogenase activity in the major and minor populations of lymphocytes (by immunocytochemical method) and the assessment of the functional activity of neutrophils were carried out using flow cytometry. The parameters of lymphocyte subpopulations were analyzed as percentage deviations from the age norm. The activity of intracellular dehydrogenases (succinate dehydrogenase, NADH dehydrogenase, lactate dehydrogenase) was determined by a cytomorphodensitometric method using image analysis. The statistical calculations were performed using the Statistica 10.0 program (StatSoft, USA). A decrease in NK cells and an increase in Th17 cells and activated T helper cells are usually observed in children with GD with age. The analysis of the activity of intracellular dehydrogenases revealed a decrease in the processes of oxidative phosphorylation and glycolysis in peripheral blood lymphocytes in children with GD. The functional activity of neutrophils in the majority of children with GD corresponded to the reference values.