The Significance Of The Abnormal Expression Of Interleukin 10 In The Pathogenesis Of Systemic Lupus Erythematosus

It's well known that there is an abnormal expression of interleukin 10(IL-10) in the patients with systemic lupus erythematosus. To evaluate the significance of this abnormality in the pathogenesis of the disease, we selected 50 SLE patients and 30 normal controls to analyse the levels of IL-10 and IL-12 by ABC-ELISA. LightCycler fluorescent quantification system was used to validate the aberrant expression of IL-10 mRNA. Three-color flow cyto metric analysis was employed for the expression of intracellular cytokines (IFN-? and IL-10) and surface antigens(HLA-DR and CD80) in the patients of SLE and healthy volunteers. The results showed us that either the serum IL-10 levels or IL-10 mRNA expression was significantly increased in patients with SLE compared with the control. There was a positive linear correlation between serum IL-10 and IL-10 mRNA expression in PBMCs. IL-10 levels measured in serum and in supernate of cultured PBMCs in SLE patients with positive anti-dsDNA antibody or with lupus nephritis were significantly higher than those measured in patients with negative anti-dsDNAvantibody or without lupus nephritis respectively. The IL-10 levels are not correlative to the disease activity(SLEDAl). In the sera of SLE patients there was a decreased IL-12 concentration. Especially, those patients with higher IL-10 had lower IL-12 serum level. The positive cells expressing HLA-DR and CD80 were significantly decreased among PBMCs cultured with SLE sera compared with control. Addition of antibodies blocking IL-10 activity can increase the expression of the two molecules. Comparing the phenotype and frequency of cells that actively secrete type 1 and type 2 cytokines in systemic lupus erythematosus versus normal control, we found that monocytes were the primary source of IL-10. Furthermore, the positive rates of IL-10-producing cells among either Th2 or Tc2 cells are higher in the peripheral blood mononuclear cells with SLE. In a word, Abnormally high expression of IL-10 may contribute to the pathogenesis of SLE. It's implied that the blockade of IL-10 may be therapeutic.