Significance of changes of FL concentrations in bone marrow and peripheral blood of patients with aplastic anemia

Objective:To determine the levels of FL in bone marrow and peripheral blood of patients with aplastic anemia(AA) and investigate their relationship with clinical outcome.Method:ELISA assay was employed to determine the levels of Flt 3 ligand(FL) and stem cell factor(SCF) in bone marrow and peripheral blood of AA patients. One and two color immunofluorescence assay and flow cytometry analysis were used to trace the FL producing.Result:The levels of FL in bone marrow and peripheral blood of AA patients increased significantly and were about 25 times as high as the controls. Statistic analysis showed that there was no difference between the levels of bone marrow and the levels of peripheral blood. The levels of FL were parallel to clinical outcome and in those who were effective to the therapy the levels of FL decreased significantly in comparison with that in those fell to the therapy (P 0.01).There was no changes of the levels of SCF in pre- and post-treatment patients. Flow cytometry analysis showed that there were large quantity of FL inside of CD 3 + cells, otherwise CD 3 + cells from AA patients expressed FL on its membrane and there was almost no FL existed inside the cells.Conclusion:The levels of FL in bone marrow and peripheral blood significantly increased and they mainly secreted from CD 3 positive cells. The changes of FL concentration in bone marrow or peripheral blood were important prognostic factors for AA patients.