Cerebrospinal fluid myelin basic protein as a prognostic biomarker in dogs with thoracolumbar intervertebral disk herniation

Abstract

BACKGROUND: Release of myelin basic protein (MBP) into the cerebrospinal fluid (CSF) is associated with active demyelination and correlates with outcome in various neurological diseases. HYPOTHESIS/OBJECTIVES: To describe associations between CSF MBP concentration, initial neurological dysfunction, and long-term ambulatory outcome in dogs with acute thoracolumbar intervertebral disk herniation (IVDH). ANIMALS: 574 dogs with acute thoracolumbar IVDH and 16 clinically normal dogs. METHODS: Prospective case series clinical study. Signalment, initial neurological dysfunction as determined by a modified Frankel score (MFS), and ambulatory outcome at > 3 month follow-up were recorded. Cisternal CSF MBP concentration was determined using an enzyme-linked immunosorbent assay (ELISA). Associations were estimated between CSF MBP concentration and various clinical parameters. RESULTS: Dogs with thoracolumbar IVDH that did not ambulate at follow-up had a higher CSF MBP concentration (median, 3.56 ng/ml; range, 0.59-51.2 ng/ml) compared to control dogs (median, 2.22 ng/ml; range, 0-3.82 ng/ml) (P = 0.032). A CSF MBP concentration of ≥ 3 ng/ml had a sensitivity of 78% and specificity of 76% to predict an unsuccessful outcome based on receiver-operating characteristics curve analysis (area under the curve = 0.688, P=0.079). Affected dogs with a CSF MBP concentration ≥ 3 ng/ml had 0.09 times the odds of ambulation at follow-up compared to affected dogs with CSF MBP concentration <3 ng/ml when adjusted for initial MFS (95% CI 0.01-0.66, P = 0.018). CONCLUSIONS AND CLINICAL IMPORTANCE: These results would suggest that CSF MBP concentration may be useful as an independent prognostic indicator in dogs with thoracolumbar IVDH.