Glucocorticoid downregulates expression of IL-12 family cytokines in systemic lupus erythematosus patients.

OBJECTIVE: This study aims to investigate expression of interleukin 12 (IL-12) family cytokines IL-12, IL-23, IL-27 and IL-35 in systemic lupus erythematosus (SLE) patients and the effect of glucocorticoid (GC) treatment on their expression.
METHODS: Plasma concentration of IL-12, IL-23, IL-27, IL-35, IL-6 and anti-double-stranded DNA (dsDNA) antibodies in 30 newly diagnosed severe SLE patients and 30 matched healthy subjects was measured by enzyme-linked immunosorbent assay. The correlation between the levels of IL-12 family cytokines and the levels of IL-6 or anti-dsDNA antibodies was analyzed by Spearman rank correlation.
RESULTS: Significantly higher levels of plasma IL-12, IL-23, IL-27, IL-35, IL-6 and anti-dsDNA antibodies were observed in SLE patients compared with healthy controls (p < 0.05), and after prednisone treatment, the serum levels of IL-12 family cytokines decreased significantly. Moreover, serum levels of IL-12, IL-23, IL-27 and IL-35 were correlated with serum levels of IL-6 and anti-dsDNA antibodies in pre-treatment as well as post-treatment SLE patients.
CONCLUSIONS: SLE patients have increased plasma levels of IL-12 family cytokines and GCs can downregulate the expression of them in SLE patients. Therefore, members of the IL-12 family may be involved in the pathophysiological process of SLE.