Increased expression of CD40 ligand by peripheral blood mononuclear cells in patients with systemic lupus erythematosus

AIM: To investigate expression and function of CD40 ligand by peripheral blood mononuclear cells (PBMCs) in patients with systemic lupus erythematosus (SLE). METHODS: Expression of CD40 ligand by PBMCs in patients with SLE and control were examined by flow cytometric analysis before and after stimulated by phytohemagglutinin(PHA)and depressed by Dexamethasone(Dex). The correlation between expression of CD40 ligand and SLE activity index(SLEDAI) was analysed in patients with SLE. RESULTS: The expression of CD40 ligand by PBMCs in patients with active SLE was higher than that in patients with inactive SLE and control. Though the expression of CD40 ligang by PBMCs could be stimulated by PHA in three groups, it was the highest in patients with active SLE. Dex depressed the expression of CD40 ligand by PBMCs significantly in patients with SLE , but not in control. There was high positive correlation between expression of CD40 ligand and SLEDAI in patients with active and inactive SLE. CONCLUSION: Increased expression of CD40L by PBMCs in patients with SLE may play an important role in pathogenesis of SLE.