Objective: To investigate the change of B-cell activating factor of the TNF family (BAFF) and regulatory T-cells (Tregs) before and after high-dose dexamethasone(HD-DXM) therapy and assess the effect of BAFF on Treg cells in immune thrombocytopenic purpura (ITP).
Methods: The plasma BAFF concentration was measured by ELISA, and Treg cell numbers by flow cytometry.
Results: The plasma BAFF level \[(599.70 +/- 199.40) pg/ml\] was significantly increased (P < 0.05), and the percentage of Treg cells \[(1.56 +/- 0.73)%\] was significantly decreased (P < 0.01) in ITP patients before treatment as compared with that in controls \[(454.5 +/- 132.5) pg/ml and (4.08 +/- 1.08)%, respectively\]. After treatment with HD-DXM, the plasma BAFF level \[(296.9 +/- 119.7) pg/ml\] was significantly decreased (P < 0.01), and the percentage of Treg cells \[(5.94 +/- 2.22)%\] was significantly increased (P < 0.01). The BAFF level and Treg proportion had no significant correlation with platelets count (P > 0.05). In in vitro assays, no difference was found in the number of Treg cells between rhBAFF0 group and rhBAFF20 group \[(1.53 +/- 0.69)%, (1.49 +/- 0.67)%, P = 0.89)\].
Conclusion: BAFF level was increased and Treg cells decreased in ITP patients. HD-DXM might play a role in ITP treatment by down-regulating BAFF expression and up-regulating Treg cells number. BAFF had no influence on the number of Treg cells.