Effect of Cetuximab on the Development of Epidural Fibrosis based on CD105 and Osteopontin Immunohistochemical Staining.

Study Design. The effect of cetuximab on the development of epidural fibrosis (EF) was assessed using immunohistochemical methods as well as antibodies for CD105 and osteopontin (OPN). Objective. The goal of this study was to assess of EGFR inhibition for the postoperative treatment of fibrosis. Summary of Background Data. EF is one of most common causes of failed back surgery syndrome, which occurs after laminectomy. Numerous causes and mechanisms have been proposed to explain its development after laminectomy. Many agents have been tested to prevent the development of EF. EGFR, a multi-functional transmembrane glycoprotein, causes cell growth, proliferation, and EF by interacting with epidermal growth factor and TGF-b1. The inhibition of postoperative fibrosis using cetuximab, an epidermal growth factor receptor blocker, is theoretically possible. However, this has not been tested to date. Methods. Sixteen Wistar-Albino rats were divided into two groups, namely, control and cetuximab groups. L1-2 laminectomy alone was performed in both groups, and topical cetuximab was applied to the treatment group. After 6 weeks, rats were sacrificed and examined histopathologically and immunohisto-chemically; EF tissue was also graded. Statistical significance was accepted at P< 0.05. Results. Fibroblast counts and fibrosis density, determined by histopathologic examination, and EF, according to immunohistochemical assessment based on CD105, were found to be higher in the treatment group than in the control group, and this was statistically significant (P< 0.001). Based on OPN staining, the results were consistent with classical methods, and no significant difference was detected among the groups (P 1/4 0.358). Conclusion. Our study revealed that cetuximab inhibits the development of EF and that CD105, and not OPN, is a reliable marker for grading EF. In addition, cetuximab did not result in toxic, systemic side effects in surrounding tissues.