Abnormal expressed co-stimulating factors and their relationship to activation of T lymphocytes in patients with aplastic anemia
Objective To investigate the phenotypes and expression of activated T cell membrane molecules on lymphocytes in the peripheral blood(PB) and bone marrow(BM) of the patients with aplastic anemia. Mothed Single and double colors immunoflourescence were used to analyze the mononuclear cells from PB and BM of the AA patients by flow cytometry. Results The expression of CD8 increased and ratio of CD4 + to CD8 + cells decreased significantly. The expression of CD25 and HLA-DR increased in the BM, which was more significant in patients with serious AA (P0.01) and the CD16 or CD56 positive cells also increased in BM. Two-colors analysis showed that the most activated T cells were CD8 + cells. The CD8 +-CD25 + lymphocytes increased significantly in the BM (P0.01). Co-stimulatory molecules which essential to activation of lymphocytes such as 4-1BB, CD95L and CD40L increased significantly in the BM of AA patients. Conclusion Increase of co-stimulating molecules which were necessary for lymphocytes activation in the BM of AA patients is one of main reason to explain abnormal T cells activation and failure of hematopoiesis.