As shown in Fig. 4c, the P-values determined by two-way anova were both < 0·001. In addition, we analysed the phosphorylation levels of STAT-3 and STAT-1 after rhIL-10 stimulation in six LN patients, seven non-LN patients and seven healthy controls. As shown in Fig. 4d, the phosphorylation levels of STAT-3 after rhIL-10 stimulation in LN patients were significantly lower than in non-LN patients and healthy controls, P < 0·05. Figure 4d also shows the average phosphorylation levels of STAT-3 in the subdivided groups according
to the SLEDAI and LN. Although the patients with selleck simultaneously active SLE and LN disease manifested the lowest phosphorylation levels of STAT-3, the sample number was too small to perform a statistical analysis. There were no
differences in the phosphorylation levels of STAT-3 in newly diagnosed SLE patients, treated patients and healthy controls. For STAT-1, we also observed delayed phosphorylation in SLE patients; however, the phosphorylation levels were similar among controls, active patients, inactive patients, LN patients PD0332991 and non-LN patients. In summary, our data suggest that IL-10 signalling is defective in patients with LN and in active SLE patients. We observed significantly higher plasma IL-6 and lower plasma IL-2 levels in all SLE patients than in healthy controls, but observed similar levels of IL-6 and IL-2 in LN and non-LN patients. Plasma IL-10 levels were significantly higher in LN patients than in controls, but not in non-LN patients. The plasma IFN-γ concentrations of patients and controls were all close to the lowest detection limit of the assay, and were not taken into consideration. The results are displayed in Table 2. There was a negative correlation between plasma IL-10 levels and IL-10R1 levels on CD4+ and CD8+ T cells, indicating that IL-10 and its receptor on T cells Tryptophan synthase may have some regulatory effect on each other.
Plasma IL-6 and IL-2 levels were not correlated with IL-10R1 expression. Plasma IL-10, IL-6 and IL-2 levels were not correlated with SLEDAI. SLE is clinically heterogeneous, and individual cytokine patterns will be more or less important to different disease manifestations and subtypes of patients . In this study we investigated the expression and signalling of IL-10R1 in SLE patients to elucidate the role of the IL-10 signalling pathway in the pathogenesis of SLE. We found that the patients with LN expressed lower levels of IL-10R1 on CD4+ cells than controls and non-LN patients. The patients with LN also expressed lower levels of IL-10R1 on CD8+ cells than non-LN patients, but not lower than controls. Moreover, the expression levels of IL-10R1 on CD4+ and CD8+ T cells were correlated negatively with SLE disease activity.