Upregulated expression of chemokines in herniated nucleus pulposus resorption

Study Design. Immunohistologic examination was performed on surgically removed samples of herniated nucleus pulposus. Objectives. To determine what cell types-predominate in the granulation tissues of herniated nucleus pulposus, and to elucidate whether chemokines are involved in the resorption process of herniated nucleus pulposus. Summary of Background Data. The study population consisted of 30 patients suffering from herniated nucleus pulposus. five macroscopically normal discs were, obtained from spinal cord tumor and spinal cord injury managed with anterior discectomy (age range, 27-63 years) as a healthy control group. Methods. Immunohistochemical analysis was used to analyze the expression of chemokines. Results. A marked infiltration of macrophage and vascular proliferation was identified with a T lymphocyte infiltration of mild degree in the granulation tissues. This tendency was more prominent in the exposed group compared with the nonexposed group: infiltrating macrophages, fibroblasts,and endothelial cells in the granulation tissues strongly expressed monocyte chemotactic protein-1 and macrophage inflammatory protein-1 alpha. Statistical analysis demonstrated that the exposed group was more abundant in Factor VIII, monocyte chemotactic protein-1, and macrophage inflammatory protein-1 alpha positive cells than the unexposed group. Conclusions. Inflammatory cells and their positivity for chemokines, such as monocyte chemotactic protein-1 and macrophage inflammatory protein-1 alpha; are associated with blood vessels. Chemokines, such as; monocyte chemotactic protein-1 and macrophage inflammatory protein 1 alpha, were overexpressed in macrophages, fibroblasts, and endothelial cells, suggesting that these chemokines contribute to activation and recruitment of macrophages in a paracrine or autocrine fashion.