Quantitative Proteomics of Vestibular Schwannoma Cerebrospinal Fluid: A Pilot Study

This pilot study aimed to identify candidate proteins for future study that are differentially expressed in vestibular schwannoma (VS) cerebrospinal fluid (CSF) and to compare such proteins with those previously identified in perilymph and specimen secretions. CSF was collected intraoperatively prior to removal of untreated sporadic VS (3 translabyrinthine, 3 middle cranial fossa approaches) and compared with reference CSF samples. After proteolytic digestion and iTRAQ labeling, tandem mass spectrometry with ProteinPilot was used to identify candidate proteins. Of the 237 proteins detected, 13 were dysregulated in ≥3 of the 6 VS patients versus controls, and 13 were dysregulated (12 up, 1 down) in samples from patients with class D versus class B hearing. Four perilymph proteins of interest were dysregulated in ≥1 VS CSF samples. Thus, 26 candidate VS CSF biomarkers were identified that should be considered in future VS biomarker and tumor pathophysiology investigations.