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

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 among CSF MBP concentration, initial neurological dysfunction, and long-term ambulatory outcome in dogs with acute thoracolumbar intervertebral disk herniation (IVDH). ANIMALS Fifty seven [corrected] 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 by an 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 with control dogs (median, 2.22 ng/mL; range, 0-3.82 ng/mL) (P=.032). A CSF MBP concentration of >or=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=.079). Affected dogs with a CSF MBP concentration>or=3 ng/mL had 0.09 times the odds of ambulation at follow-up compared with affected dogs with CSF MBP concentration<3 ng/mL when adjusted for initial MFS (95% confidence interval 0.01-0.66, P=.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.