Both the phenomenon of activating immune system of alimentary tract (GALT- gut associated lymphoid tissue) after gluten challenge as well as the role of cellular immune response in the development of morphological changes of intestinal mucosa in children with coeliac disease are well known. The introduction of new laboratory techniques and flow cytometry in particular, as well as the use of monoclonal antibodies opened new possibilities in the studies upon correlation between processes taking place in GALT and the changes within peripheral blood lymphocytes. At the same time, a question emerged whether these studies will allow to reduce the frequency of biopsy of intestinal mucosa in children with malabsorption syndrome, especially after gluten challenge. The aim of our study was to assess the diagnostic value of changes in the expression of selected CD antigens on T cells in peripheral blood as a result of gluten challenge. The intensification of CD3, CD19 and CD69 expression on peripheral blood lymphocytes was investigated before and after introducing gluten into the diet of 13 children with coeliac disease and of 7 children with secondary coeliac syndrome. Monoclonal antibodies and flow cytometry were used. The results obtained varied greatly in both groups. It was found that T cells activation prevails in children with coeliac disease, while in the case of children with secondary coeliac syndrome, the tendency for B cells activation is dominant. These differences, however, are not statistically significant. It is likely that the inflow of T and B cells with CD69 expression to circulation which is intensified by gluten challenge, is compensated by equally intensive homing of the lymphocytes in the mucous membrane of alimentary tract. Thus, the assessment of the intensification of CD69 expression on T and B cells of peripheral blood is useful neither in the differentiation between coeliac disease and secondary malabsorption syndrome, nor in the determination of disease intensity.

Keywords: peripheral blood lymphocytes, CD69 antigen, coeliac disease, children