AUTHOR=Bielewicz Joanna , Daniluk Beata , Kamieniak Piotr 

TITLE=Metalloproteinase-2 in failed back surgery syndrome caused by epidural fibrosis: can it play a role in persistent pain?

JOURNAL=Frontiers in Human Neuroscience

VOLUME=17

YEAR=2023

URL=https://www.frontiersin.org/journals/human-neuroscience/articles/10.3389/fnhum.2023.1248943

DOI=10.3389/fnhum.2023.1248943

ISSN=1662-5161

ABSTRACT=<sec id="sec1"><title>Purpose</title><p>Failed Back Surgery Syndrome (FBSS) occurs in 10–40% of patients treated surgically due to disk herniation (DH). There are several factors that can cause a predisposition to FBSS, but the exact pathomechanism has not been elucidated. The aim of this study was to investigate Metalloproteinase-2 (MMP-2) and Tissue Inhibitor of Metalloproteinase-2 (TIMP-2) activities in a homogeneous group of FBSS patients with epidural fibrosis in comparison to its activity in patients with surgically treated DH.</p></sec><sec id="sec2"><title>Methods</title><p>DH, FBSS, and control (CG) groups consisted of 30 subjects. The patients were assessed clinically by the Numerical Rating Scale (NRS), McGill Pain Questionnaire (SF -MPQ), Oswestry Disability Index (ODI), and Beck Depression Inventory (BDI). Serum concentrations of MMP-2 and TIMP-2 were measured by using the immunoenzymatic method.</p></sec><sec id="sec3"><title>Results</title><p>There was a significantly higher MMP-2 expression (medians: 4797.49 vs. 2656.65; <italic>p</italic> &lt; 0.0001) and TIMP-2 concentration (medians: 166.40 vs. 109.60; <italic>p</italic> &lt; 0.0001) in the DH compared to the CG. Significantly higher MMP-2 expression (4219.95 vs. 2656.65; <italic>p</italic> &lt; 0.0001) and TIMP-2 concentration (medians: 150.17 vs. 109.60; <italic>p</italic> = 0.0003) were also found in the FBSS compared to the CG. The activity of MMP-2, measured as MMP-2/TIMP-2, did not significantly change between the DH, FBSS, and CG. MMP2 expression (<italic>p</italic> &lt; 0.0001) and TIMP-2 concentration (<italic>p</italic> &lt; 0.0001) were significantly higher in the DH than FBSS.</p></sec><sec id="sec4"><title>Conclusion</title><p>Results indicate the presence of a contribution of MMP-2 and TIMP-2 in DH and FBSS. Unchanged activity of MMP-2 can indicate an insufficiency in the MMP-2 repair system in both diseases. Lower MMP-2 expression and TIMP-2 concentration in the FBSS group can reflect the chronicity of the process.</p></sec>