Expression pattern of matrix metalloproteinases-2 and -9 and their tissue inhibitors in patients with chronic inflammatory demyelinating polyneuropathy

Background: Matrix metalloproteinases (MMPs) are a heterogeneous family of endopeptidases that play a role in many physiological functions, including the immune response. An imbalance between the activity of MMPs and their physiological tissue inhibitors (TIMPs) has been proposed in the pathophysiology of different autoimmune disorders. We aimed to assess the plasmatic levels of MMP-2, MMP-9, and their inhibitors TIMP-1 and -2 in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Subjects and methods: Twenty patients with CIDP and 20 age- and sex-matched healthy controls were enrolled. Plasma concentrations of MMP-2, MMP-9, TIMP-1, and TIMP-2 were determined by the enzyme-linked immunosorbent assay. Results: CIDP subjects had higher MMP-9 concentrations along with TIMP-1 downregulation when compared to controls, with the consequent increase in the MMP-9/TIMP-1 ratio (p<0.000002 for all measures). Conversely, the concentration of MMP-2 was lower in the CIDP group (p<0.01) without changes in the TIMP-2 concentration. The MMP-2/TIMP-2 ratio was decreased in the patients’ group (p<0.02). Discussion: We provide first preliminary evidence that the plasmatic pattern of MMPs and TIMPs is markedly altered in patients with CIDP. Future studies are needed to assess the potential usefulness of these new biomarkers in the clinical setting.