Disease severity in patients with systemic lupus erythematosus correlates with an increased ratio of interleukin‐10: Interferon‐γ–secreting cells in the peripheral blood

OBJECTIVE: To compare the phenotype and frequency of cells that actively secrete type 1 and type 2 cytokines in systemic lupus erythematosus (SLE) patients (n = 46), versus normal controls (n = 60). METHODS: ELISPOT analysis of freshly isolated peripheral blood mononuclear cells (PBMC). RESULTS: T cells were the major source of interleukin-2 (IL-2), IL-4, and interferon gamma (IFN gamma), whereas monocytes were the primary source of IL-6 and IL-10 in the PB of lupus patients. Significantly fewer PBMC spontaneously secreted IFN gamma and IL-2 (P > or = 0.03), while significantly more PBMC produced IL-6 and IL-10 (P < 0.001), in lupus patients versus controls. Disease severity in lupus patients correlated with an elevated ratio of IL-1O:IFN gamma-secreting cells (P < 0.001). CONCLUSION: SLE is characterized by an imbalance in the ratio of type 1:type 2 cytokine-secreting PBMC.