Analysis of interleukin-6, interleukin-10 and leukemia inhibitory factor (LIF) production by peripheral blood cells from patients with systemic lupus erythematosus identifies LIF as a potential marker of disease activity.

The objective of this study was to determine the extent of interleukin (IL)-6, -10 and/or LIF involvement in systemic lupus erythematosus (SLE). Specific ELISA were used to measure cytokines in the supernatants of 48 hours cultures of whole blood stimulated or not by lipopolysaccharide and phytohemagglutinin, from controls (n = 10) or SLE patients divided according to the median of the SLE activity measurements (SLAM): < 9, group 1 (n = 11), and 9, group 2 (n = 10). Comparing median basal and stimulated cytokine concentrations from patients and controls, IL-6 was significantly higher in all SLE patients, IL-10 was significantly higher in both non- and stimulated situations only for SLE group 1 patients. With regard to LIF, it was significantly enhanced only in stimulated cultures of whole blood from group 2 patients as compared to control subjects. In conclusion, the production of cytokines involved in B-cell regulation and inflammation was altered in SLE, and LIF appears to be a potential marker of disease activity.