Decreased production of interleukin-12 and interferon-? is associated with renal involvement in systemic lupus erythematosus

OBJECTIVE: To analyze the type 1/type 2 cytokine balance in patients with systemic lupus erythematosus (SLE) according to the presence of renal disorder and activity status. METHODS: We measured the serum levels of type 1 (IFN-gamma, IL-12) and type 2 cytokines (IL-4, IL-10) as well as spontaneous and stimulated cytokine production from peripheral blood mononuclear cells (PBMC) in 40 patients with SLE. RESULTS: Patients with lupus nephritis (LN) showed significantly lower levels of serum IL-12 and IFN-gamma than those without LN. Production of IL-12 and IFN-gamma by stimulated PBMC were also decreased in patients with LN. The circulating IL-12 correlated positively with IFN-gamma, but inversely with IL-10. The SLEDAI scores correlated well with the ratio of IL-4/IFN-gamma levels. CONCLUSION: The reduced production of IL-12 and IFN-gamma and the resultant shift towards the type 2 cytokine phenotype may be associated with LN.