Decreased level of interleukin 27 in patients with active Behçet’s disease. (A) Relative gene expression of the interleukin (IL) subunits p28 and EBI3 in peripheral blood mononuclear cells (PBMCs) from patients with active Behçet’s disease (BD) (n = 8), patients with inactive BD (n = 8) and healthy controls (n = 8) was measured by real time PCR. The results of these experiments are presented as expression relative to β-actin. Analysis of variance (ANOVA) was used for statistical analysis. (B) IL-27 levels in sera from patients with active BD (n = 19), patients with inactive BD (n = 20) and healthy controls (n = 20) were assessed by enzyme-linked immunosorbent assay. Kruskal–Wallis and Mann–Whitney U tests were carried out for statistical analyses, followed by the Bonferroni correction (P
c) for comparison of the three groups. P
c < 0.05 was considered significant. (C) IL-27 production by PBMCs from patients with active BD (n = 6), patients with inactive BD (n = 6) and healthy controls (n = 6) cultured with or without Staphylococcus aureus Cowan Strain I (SAC) was examined. A paired-samples t- test for related samples and one-way ANOVA for independent samples were performed for statistical analysis. The Bonferroni correction was used to correct for multiple comparisons. The statistical significance values of data before SAC stimulation were as follows: P = 0.003 and P
c = 0.009 for healthy controls vs patients with active BD, and P = 0.007 and P
c = 0.021 for patients with inactive BD vs patients with active BD. After SAC stimulation, the statistical significance values for comparisons were as follows: P = 0.0032 and P
c = 0.010 for healthy controls vs patients with active BD and P = 0.0064 and P
c = 0.019 for patients with inactive BD vs patients with active BD. All data are representative of five experiments and are expressed as average ± standard deviation.