Effect of high-dose dexamethasone on BAFF and Tregs in patients with immune thrombocytopenic purpura.

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). The plasma BAFF concentration was measured by ELISA, and Treg cell numbers by flow cytometry. 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 th