Disturbed Th1, Th2, Th17 and Treg balance in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease accompanied by disturbed T-cell homeostasis. Dysbalance of T-helper-cell (Th) subsets (Th1/Th2/Th17) and regulatory T-cells (Tregs) is suggested to contribute to the pathogenesis of SLE. Recent reports suggest functional deviation of Tregs in terms of producing IL-17A, a process that may be aberrant in SLE. Therefore, we analyzed these T-cell subsets in SLE to test the hypothesis that aberrant T-cell subset skewing is present in SLE-patients. We investigated simultaneously the intracellular cytokines IFN-γ, IL-4 and IL-17A in CD4+T-cells as well as in Tregs. Skewing of T-cell subsets towards Th17 cells was observed in SLE-patients. Although the proportion of Tregs was similar between SLE-patients and healthy controls, the ability of Tregs to express IFN-γ and IL17A was impaired in SLE-patients. Even in quiescent SLE-patients T-cell homeostasis is aberrant in terms of skewing towards IL-17 producing T-cells.