Correlation of TLR2 and TLR4 expressions in peripheral blood mononuclear cells to Th1- and Th2-type immune responses in children with henoch-schönlein purpura.

We discussed the correlation of TLR2 (Toll-like receptor) and TLR4 expressions in peripheral blood mononuclear cells (PBMCs) to Th1- and Th2-type immune responses in children with Henoch-Schönlein Purpura (HSP). The role of TLR2 and TLR4 in the pathogenesis of HSP was analyzed. Sixty-four HSP children treated at our hospital from October 2011 to November 2012 were enrolled and divided into NHSPN group (complicated by renal impairment, 36 cases) and HSPN group (not complicated by renal impairment, 28 cases). In the meantime, 30 normal children receiving physical examination at our hospital were recruited as controls. Peripheral blood T cell subgroups and TLR2 and TLR4 expressions in PBMCs were detected by using flow cytometry; relative expression levels of TLR2 and TLR4 mRNA in PBMCs by real-time quantitative fluorescence PCR, and plasma levels of IFN-γ, IL-4 and IL-6 by ELISA method. Relative expression levels of TLR2 and TLR4 mRNAs in PBMCs and TLR2 and TLR4 protein expressions in children with HSP were significantly higher than those of the controls (P<0.01). The relative expression levels of TLR2 and TLR4 mRNAs in PBMCs and TLR2 and TLR4 protein expressions in HSPN group were obviously higher than those in NHSPN group (P<0.05; P<0.01; P<0.01; P<0.01); CD3(+) T cells and CD3(+)CD4(+) T cells in HSP group were significantly decreased, while CD3(+)CD8(+) T cells and CD3(+)HLADR(+) T activated cells were considerably increased (P<0.01); The plasma levels of IL-4 and IL-6 in HSP group were significantly higher than those of the normal controls (P<0.01, P<0.01); IFN-γ level in the former was much lower than in the control group (P<0.05); IFN-γ/IL-4 ratio in the former was also lower than that in the control (P<0.01); TLR2 and TLR4 expressions in HSP group showed significantly positive correlation with the plasma levels of IL-4 and IL-6 (P<0.01, P<0.05; P<0.01, P<0.01) and significantly negative correlation with IFN-γ/IL-4 ratio (P<0.01; P<0.01). TLR2 and TLR4 activation may be involved in the pathogenesis of HSP. TLR2 and TLR4 overactivation may induce HSP-related renal impairment; Children with HSP showed T-cell disorders and Th1/Th2 imbalance. Activated TLR2 and TLR4 possibly mediate the pathogenesis of HSP by upregulating Th2-type immune responses.