Sera from children with active Henoch-Schönlein purpura can enhance the production of interleukin 8 by human umbilical venous endothelial cells.

OBJECTIVE To investigate the ability of sera from children with active Henoch-Schonlein purpura (HSP) to enhance endothelial interleukin (IL) 8 production and intercellular adhesion molecule (ICAM)-1 expression. METHODS Nine children with active HSP and nine normal healthy children were enrolled. IL8 serum levels of patients and controls at different stages were analysed. Production of IL8 and expression of ICAM-1 by human umbilical venous endothelial cells were detected (ELISA for IL8, flow cytometry for ICAM-1) and compared under various stimuli, including sera of patients at different stages, sera of controls, and medium alone. RESULTS Serum levels of IL8 were increased at the acute stage. Levels of IL8 in supernatants from human umbilical venous endothelial cells (HUVEC) co-cultured with sera from children with active HSP were significantly higher than those from HUVEC without any treatment (p = 0.001), HUVEC treated with inactive sera (p = 0.004), and HUVEC treated with sera from healthy controls (p = 0.004). Sera from patients and from controls did not enhance the expression of ICAM-1 on HUVEC. CONCLUSIONS Some factors may be present in sera from children with active HSP that could activate endothelial cells to produce IL8. This process may account, in part, for the mechanisms of perivascular neutrophil infiltration and leucocytosis in HSP.