Decreased IL-4 producing CD4+ T cells in patients with active systemic lupus erythematosus-relation to IL-12R expression.

The balance of interferon-gamma (IFN-gamma) and/or interleukin-4 (IL-4) producing T cells and interleukin-12 receptor (IL-12R) expression on T cells were evaluated in patients with active systemic lupus erythematosus (SLE). Assessment of intracellular IFN-gamma and/or IL-4 were conducted with cytoplasmic staining. IL-12R presenting T cells were also assessed by flowcytometry without in vitro stimulation. In SLE, the number of IFN-gamma producing CD4+ T cells was increased, and the absolute number of IL-4 producing CD4+ T cells was significantly decreased. Although the ratio of IL-12R presenting CD4+ T cells was significantly greater, the absolute number did not increase. The ratio of IFN-gamma/IL-4-producing CD4+ T cells correlated with the SLE disease activity index (SLEDAI) and was significantly higher among patients with lupus nephritis. Therefore, the imbalance of IFN-gamma/IL-4 producing CD4+ T cells was due to the decrease in IL-4 producing CD4+ T cells and may play an important pathogenic role in active SLE.