Increased local expressions of CX3CL1 and CCL2 are related to clinical severity in lumbar disk herniation patients with sciatic pain.
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.


CONCLUSIONS
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.
Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha; Department of Spine Surgery, Chenzhou No. 1 People's Hospital, Chenzhou.
Zhen-Yu
ZY
Peng
Department of Neurosurgery, Nanhua Hospital Affiliated to Nanhua University, Hengyang.
Rui
R
Chen
Department of Spine Surgery, Chenzhou No. 1 People's Hospital, Chenzhou.
Zuo-Zhong
ZZ
Fang
Department of Spine Surgery, Chenzhou No. 1 People's Hospital, Chenzhou.
Bin
B
Chen
Department of Orthopedics, Chenzhou No. 1 People's Hospital, Chenzhou, Hunan, People's Republic of China.
Zhi-Hua
ZH
Wang
Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha.
Xi-Yang
XY
Wang
CCL2; CX3CL1; lumbar disk herniation; sciatic pain