Association of Protein and Genetic Biomarkers With Response to Lumbar Epidural Steroid Injections in Subjects With Axial Low Back Pain.

Objective: The purpose of this observational study was to examine the association of protein and genetic biomarkers with pain and pain-related disability in individuals with axial low back pain undergoing epidural steroid injections.

Design: Forty-eight adults with axial low back pain undergoing an epidural steroid injection were recruited from an academic medical center. Blood samples were assayed at baseline and follow-up for plasma proteins and functional single-nucleotide polymorphisms associated with pain. Data regarding pain and function were collected at baseline and follow-up. The characteristics of responders (defined as 50% improvement in pain score) and nonresponders were compared, and the association between response and baseline biomarkers was examined.

Results: Thirty-five percent of subjects were responders to injection. Responders had lower baseline plasma levels of chondroitin sulfate 846 and higher neuropeptide Y and serotonin levels than nonresponders, and baseline neuropeptide Y level correlated with change in disability levels. In addition, subjects with the variant allele for the catechol-O-methyltransferase single-nucleotide polymorphism demonstrated increased odds of responding to the injection.

Conclusions: These data identify candidates who may have utility for patient selection for spinal procedures and provide support for exploration in prospective studies to assess and validate their predictive ability.