Matrix metalloproteinase-9 is elevated in serum of patients with amyotrophic lateral sclerosis

Matrix metalloproteinase-9 (MMP-9) and its specific inhibitor, tissue inhib itor of matrix metalloproteinase-1 (TIMP-1), were analysed by enzyme-linked immunosorbent assay (ELISA) and by zymography in serum and cerebrospinal f luid (CSF) of patients with amyotrophic lateral sclerosis (ALS). In contras t to patients with inflammatory diseases, MMP-9 levels were not elevated in CSF of ALS patients. In serum, however, compared to healthy donors, MMP-9 was significantly (p=0.0003) increased up to levels as high as those of vir al meningoencephalitis (VM) or bacterial meningitis. (BM) patients. MMP-9 l evels remained elevated during long-term observation of ALS patients. In th e absence of an inflammatory response, the results indicate that the increa se of MMP-9 in serum of ALS patients might be caused by upregulation of MMP -9 in denervated muscles or in degenerating peripheral nerves following mot or neurone loss. NeuroReport 11:3419-3422 (C) 2000 Lippincott Williams & Wi lkins.