Abstract W MP32: Localized Increase of Chemokines in the Lumen of Human Cerebral Aneurysms

Abstract

Introduction: Inflammation may play an important role in the formation and rupture of cerebral aneurysms. Chemokines act as chemoattractants for leukocytes directing them toward sites of tissue inflammation. The purpose of this study was to determine whether chemokines and chemoattractant cytokines were increased in the lumen of human cerebral aneurysms. Methods: The concentrations of chemokines and other inflammatory molecules in blood samples drawn from the lumen of human cerebral aneurysms of 16 consecutive patients (harboring 18 aneurysms) were compared with blood samples from femoral arteries of the same patients. Specifically, the concentrations of the following molecules were determined: RANTES, monokine-induced-by-gamma-interferon (MIG), interferon-gamma-induced protein-10 (IP-10), eotaxin, interleukin (IL) 1-beta, IL 1 Receptor Antagonist, IL2, IL2 Receptor, IL4, IL5, IL6, I7, IL8, IL10, IL12, IL13, IL15, IL17, vascular endothelial growth factor, granulocyte colony stimulating factor, epidermal growth factor, basic fibroblast growth factor, granulocyte monocyte colony stimulating factor, tumor necrosis factor-alpha, interferon-alpha, interferon-gamma, macrophage inflammatory protein 1 alpha, macrophage inflammatory protein-1-beta, and monocyte chemoattractant protein-1 (MCP-1). Results: The mean plasma concentration of RANTES, MIG, IP-10, eotaxin, IL 8, and IL17 was significantly higher in samples taken from cerebral aneurysms compared with femoral arteries. In contrast, plasma concentrations of all remaining inflammatory molecules (except IL6) that were tested did not differ between cerebral aneurysms and femoral arteries. For unruptured aneurysms, there was a significantly higher mean plasma concentration of monocyte chemoattractant protein-1,RANTES, MIG, IP-10, eotaxin, IL8, and IL17 in samples obtained from cerebral aneurysms. Conclusions: High plasma concentrations of chemokines (monocyte chemoattractant protein-1, RANTES, MIG, IP-10, and eotaxin) and chemoattractant cytokines (IL8 and IL17) were found in the lumen of human cerebral aneurysms. These findings suggest that there may be an active recruitment of inflammatory cells into the aneurysm wall that may be exploited therapeutically.