Expression And Significance Of CD40 Ligand On Peripheral Blood Mononuclear Cell In Patients With Myasthenia Gravis

Objectives: (l)To investigate the role of CD40 and CD40 ligand in the pathogenesis of myasthenia gravis (MG) , the CD40L expression on the peripheral blood mononuclear cells of patients with MG was tested. (2) To investigate the signal transduction pathway involved in CD40L expression of patients with MG.Methods: 25 patients with MG included 13 acute patients and 12 non-acute patients. 15 healthy people was acted as control group. Blood of patients and normal controls was collected. Mononuclear cells in peripheral blood(PBMC) were isolated and cultured in the medium(RPMI-1640) supplemented with PMA and A23187 or PHA. After 6 hours, cell samples were collected and CD40L expression was tested by flow cytometry and reverse transcription-polymerase chain reaction(RT-RCR) compared with that of them before activation. Except for PMA and A23187 or PHA treatment, a specific inhibitor of PKC, bisindolylmaleimide(BLM),was added to the cells before exposure to PHA in patients with acute MG. Meanwhile, the medium without activator in PBMC cultures was used in acute MG .Cells indifferent culture medium were collected and CD40L expression was tested .Results: (1) CD40L expression on PBMC in patients with acute MG was increased markedly compared with that of patients with non-acute MG and normal controls before activation, but there were no significantly statistics differences between patients with non-acute MG and normal controls. (2)CD40L expression of patients with acute MG and non-acute MG were increased significantly in contrast to that of normal controls after activation with PHA or PMA CD40L expression of patients with acute MG still increased markedly compared with that of patients with non-acute MG. (3)CD40L expression of patient with acute MG after activation with PHA was not different from that after activation with PMA, but there was increased markedly in contrast to that of the status of medium without activator. CD40L expression in the presence of the PKC inhibitor was no significantly difference compared with that of the status of medium without activator.Conclusions: (1) Hyperexpression of CD40L is correlated with the clinical progression of MG. (2) CD40L expression in MG is mediated by PKC activity.