High levels of TH2 cytokine gene expression in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease with a clear imbalance in the network made up of different cytokines. However this statement has been derived from studies which have focused on the analysis of some specific cytokines and few have simultaneously analyzed those cytokines that could be involved in the pathogenesis of SLE. Therefore, we decided to analyze interleukin IL-1b, IL-2, IL-4, IL-6, IL-10, tumor necrosis factor-a (TNF-a) and gamma interferon (IFN-g) gene expression in peripheral blood mononuclear cells from 17 women with SLE and 10 normal females by a coupled reverse transcriptase-polymerase chain reaction technique. High gene expression of IL-4, IL-6, IL-10 and TNF-a was found in SLE patients as compared to normal subjects. The expression of IL-1b, IL-2 and IFN-g genes was low or undetectable. The resulting high level of cytokines with strong effect on proliferation and differentiation of B lymphocytes in SLE could be responsible for the characteristic B cell hyperactivity and autoantibody production seen in SLE.