Influence of macrophage polarization in herniated nucleus pulposus tissue on clinical efficacy after lumbar discectomy

Abstract

Background Low back pain or sciatic pain because of lumbar intervertebral disc herniation (LDH) is caused by mechanical compression and/or an inflammatory component on the nerve root. However, it is difficult to define to what extent each component contributes to the pain. This study attempted to explore the effects of macrophage polarization on clinical symptoms in patients experiencing LDH after surgery, and investigated the association between macrophage cell percentages and clinical efficacy. Methods This study retrospectively harvested nucleus pulposus (NP) tissue samples from 117 patients. Clinical symptoms and efficacy using the visual analog scale (VAS) and Oswestry Disability Index (ODI) were evaluated at different time points preoperatively and postoperatively. CD68, CCR7, CD163, and CD206 were selected as macrophage phenotypic markers. Results Seventy‐six samples showed positive expression of macrophage markers in NP samples of patients with LDH, whereas 41 patients displayed negative results. No significant differences were detected between the two groups, involvement of several demographic data, and preoperative clinical findings. With respect to the macrophage‐positive group, no significant correlation was detected between the positive rate of the four markers and the VAS score or ODI after surgery. However, patients with NP samples positive for CD68 and CCR7 expression showed significantly lower VAS scores 1 week after surgery compared with those in the negative group. Moreover, the improvement in VAS score showed a strong positive correlation with CD68‐ and CCR7‐positive cell percentages. Conclusions Our results indicated that pro‐inflammatory M1 macrophages may be associated with the reduction of chronic pain after surgery. Therefore, these findings contribute to better personalized pharmacological interventions for patients with LDH, considering the heterogeneity of pain.

Inflammatory Myofibroblastic Tumor of the Sciatic Nerve Mimicking Lumbar Disc Herniation: A Diagnostic Challenge

“…Lumbar disc herniation (LDH) is a common cause of low back or radicular pain [1]. A majority of the underlying mechanisms, such as mechanical compression of the nerve root or inflammatory stimulation of the nerve root, have been proposed to explain the etiopathogenesis of pain [2,3]. Among the components that contribute to pain, functional disorders involving immune cells, such as macrophages or T cells, can play vital roles in this process [4][5][6][7].…”