Metalloproteinases-9 and Neutrophil Gelatinase-Associtated Lipocalin Plasma and Tissue Levels Evaluation in Middle Cerebral Artery Aneurysms

Background. Cerebral aneurysms are relatively common in adults, with a prevalence ranging between 1% and 5%. Subarachnoid hemorrhage, following aneurismal rupture, is a major cause of death and disability in these patients. Matrix Metalloproteinases (MMPs) and Neutrophil Gelatinase- Associated Lipocalin (NGAL) seem to be involved in the pathogenesis and in the clinical course of aneurysms. In this study, we evaluated the relationship between tissue and plasma levels of MMP-9 and NGAL in patient with ruptured and unruptured middle cerebral artery aneurysms. Methods. An open label study was conducted on 7 patients with middle cerebral aneurysms. Three patients had ruptured aneurysms (Group I) and four patients had unruptured aneurysms (Group II). All patients underwent aneurysm clipping. Plasma levels of MMP-9 and NGAL were evaluated through ELISA Test. During the surgery, biopsies of the aneurysmatic arteries were taken and frozen ( 80°C) for Western blot evaluation of MMPs and NGAL expression. Four healthy volunteers (Group III) represented the control group for ELISA testing. Results. Both plasma MMP-9 and NGAL levels were significantly high in aneurysmatic patients respect to those of control patients, and these levels were higher (P 0.01) in patients with ruptured aneurysms respect to patients with unruptured aneurysms (P 0.01). The latest findings were similarly evident in tissue evaluation of MMP-9 and NGAL between ruptured and unruptured aneurysms. Conclusion. This study suggests that MMP-9 and NGAL plasma levels may be useful to predict the clinical course of a cerebral aneurysms in order to evaluate the progression of the disease and the tendency of an aneurysm to rupture.