OPN polymorphism is associated with the susceptibility to cervical spondylotic myelopathy and its outcome after anterior cervical corpectomy and fusion

Background: Osteopontin (OPN) is reportedly involved in bone desorption, formation and ectopic calcification. We sought to investigate the role of OPN gene polymorphism in the susceptibility to Cervical spondylotic myelopathy (CSM) and in predicting the outcome anterior cervical corpectomy and fusion (ACF).

Methods: A total of 187 patients diagnosed with CSM and 233 sex and age matched healthy controls were enrolled in this study. All CSM patients received ACF and were followed up for 24 months. The polymorphisms of OPN gene at 3 loci, namely, -156 G>GG, -443 C>T and -66T>G were determined.

Results: The -66T>G genotype was significantly different between CSM patients and controls. Compared to the -66TT carriers, the -66GG genotype carriers had a higher risk for developing CSM (adjusted Odd Ratio=2.58, adjusted P=0.001). In contrast, the genotype distributions of the -156G/GG and -443C/T loci were not significantly different between the CSM and control groups. OPN gene polymorphism did not determine the pre-operative severity of CSM patients, but the -66T>G genotype was significantly associated with the clinical outcome of CSM after ACF treatment. The -66T>G did not affect the serum OPN level, but affect the local expressions of OPN and a serious of key inflammatory factors in the intervertebral disc samples.

Conclusion: Our study shows the OPN -66T>G genetic polymorphism contributes to patients' susceptibility to CSM and could be indicative of the outcome of ACF surgery.