Study On T Lymphocytes Activation And Lymphocyte Subsets Of Patients With Hemophagocytic Lymphohistiocytosis

objective The haemophagocytic syndrome (HPS) is a rare but frequently fatal disorder of immune regulation. The aim of this study is to investigate the lymphocyte subsets and the activated status of T cell subsets in the peripheral blood from patient with hemophagocytic lymphohistiocytosis (HLH) and its clinical significances.Methods T cell subsets and expression of membrane molecules on activated T cells in the peripheral blood were measured in 29 HLH patients by using flow cytometry, and the results were compared with those from control group of healthy children.Results The percentage of CD4+cells, NK cells from peripheral blood in HLH patients were significantly lower than those of control group while the percentage of CD8+cells and the expression of CD8+CD25+, CD8+CD69+, CD8+HLA-DR+, CD4+HLA-DR+on T cells were significantly higher than those of control. A ratio of CD4+/CD8+was disproportion. The patients alive had lower expression of CD4+HLA-DR+on T cells and CD4+/CD8+ratio than those of the dead. The high expression levels of CD8+CD25+on T cells and NK cells could predict a good prognosis.Conclusion The abnormal activation of CTLs and dysfunction of NK cells play an important role in pathogenesis of HLH, which conveys the diagnosis and prognosis of children with HLH.