Journal of Pain Research (Jan 2017)
Increased local expressions of CX3CL1 and CCL2 are related to clinical severity in lumbar disk herniation patients with sciatic pain
Abstract
Zhen-Yu Peng,1,2 Rui Chen,3 Zuo-Zhong Fang,2 Bin Chen,2 Zhi-Hua Wang,4 Xi-Yang Wang1 1Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha, 2Department of Spine Surgery, Chenzhou No.1 People’s Hospital, Chenzhou, 3Department of Neurosurgery, Nanhua Hospital Affiliated to Nanhua University, Hengyang, 4Department of Orthopedics, Chenzhou No.1 People’s Hospital, Chenzhou, Hunan, People’s Republic of China Background: Chemokines have been identified to be involved in the modulation of pain through both peripheral and central mechanisms. However, the role of chemokines in lumbar disk herniation (LDH) with sciatic pain remains unknown. Objective: The current study was performed to explore the expression of two most commonly studied chemokines CX3CL1 and CCL2 and assess their associations with clinical severity in LDH patients with sciatic pain. Methods: The soft tissues around nerve root (STANR), annulus fibrosus (AF), and nucleus pulposus (NP) biopsies were obtained from 36 LDH patients with chronic sciatic pain and 10 scoliosis patients (painless controls). The serum and local expressions of CX3CL1 and CCL2 were determined using enzyme-linked immunosorbent assay and Western blot analysis, respectively. The visual analog scale (VAS) scores for low back pain and lower extremity pain and Japanese Orthopaedic Association (JOA) scores were recorded on the day of hospital admission to evaluate the clinical severity. LDH patients with sciatic pain were divided into severe pain (SP) group (VAS ≥7; n=18) and mild-to-moderate pain (M-MP) group (VAS <7; n=18) for lower extremity pain. Results: Local expressions instead of CX3CL1 and CCL2 in STANR, AF, and NP were significantly higher in the SP group than in M-MP compared with scoliosis painless group. Expressions of both CX3CL1 and CCL2 in STANR and AF were positively correlated with VAS scores for lower extremity and for low back pain, respectively. In addition, CX3CL1 and CCL2 expressions in STANR were negatively associated with JOA scores. There were no significant differences of serum CX3CL1 and CCL2 levels among SP group, M-MP group, and scoliosis painless group. Conclusion: Both CX3CL1 and CCL2 may play important roles in maintaining pain in LDH patients. Local blockade of CX3CL1 and CCL2 in LDH patients with persistent pain deserves further intensive study. Keywords: lumbar disk herniation, sciatic pain, CX3CL1, CCL2
