Th1 (IL-2, interferon-gamma (IFN-gamma)) and Th2 (IL-10, IL-4) cytokine production by peripheral blood mononuclear cells (PBMC) from patients with systemic lupus erythematosus (SLE)

We investigated the production of IL-2, IFN-gamma, IL-10 and IL-4 by PBMC f rom 24 patients with SLE and 10 healthy individuals. Basal and mitogen-stim ulated (lipopolysaccharide and phytohaemagglutinin (LPS + PHA)) cytokine pr oduction was determined in a whole blood assay (WBA). Supernatants were col lected and assayed with specific ELISAs. Although the IL-2 and IFN-gamma co ntents did not differ significantly between patients and controls under bot h conditions, statistically significant correlations were found between eac h cytokine and disease activity (SLAM index) after stimulation (respectivel y, r = 0.501, P = 0.01 and r = 0.631, P = 0.001). PBMC IL-10 production was significantly higher for patients than controls (P = 0.05), but no correla tion between IL-10 levels and the SLAM index was obtained. IL-4 production was not statistically different between SLE patients and controls. For stim ulated WBAs, the IL-10/IL-2 and IL-10/IFN-gamma ratios were significantly c orrelated with disease severity (P = 0.02; P = 0.001, respectively). Overal l, our data suggest that SLE is characterized by an elevated production of IL-10, reflecting the basal state of activation of the immune system. Durin g exacerbation of SLE, IL-2 and IFN-gamma are synthesized in larger amounts and may cause the tissue damage observed.