TLR4 and Henoch-Schoenlein purpura: TLR4, the receptor for LPS from Escherichia coli, has been reported with increased mRNA expression in peripheral lymphomononuclear cells of patients with IgAN and in children with IgA vasculitis; in addition, TLR4 is correlated with the signs of innate immunity activation and proteinuria [64, 65].