title: Inner ear protein as a biomarker in circulation?
abstract: Serum biomarkers detect the earliest events in disease, monitor management, and provide insight into disease pathogenesis. At this time, there are no biomarkers available for otologic disorders. Otolin-1 is a scaffolding protein exclusively expressed in otoconia and cells of the vestibule and the cochlea; therefore, it may be a biomarker candidate for assessing the health of the inner ear. As a proof of concept, we used serum samples from controls without otologic history and subjects with a history of benign paroxysmal positional vertigo (BPPV), performed enzyme-linked immunosorbent assay for otolin-1, and measured the optical density of the substrate. Otolin-1 was detectable and quantifiable in all subjects, indicating that this inner ear protein crosses the blood-labyrinthine barrier. Furthermore, subjects with BPPV had significantly higher levels, with about one-third being above the control range. This promising preliminary result suggests that inner ear-specific proteins have the potential to serve as biomarkers for otologic disease processes.
authors.affiliation: Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Connecticut Health Center, Farmington, Connecticut, USA parham@neuron.uchc.edu.
authors.forename: Kourosh
authors.initials: K
authors.lastname: Parham
authors.affiliation: Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Connecticut Health Center, Farmington, Connecticut, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sacks
authors.affiliation: Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Connecticut Health Center, Farmington, Connecticut, USA.
authors.forename: Catherine
authors.initials: C
authors.lastname: Bixby
authors.affiliation: Clinical Research Center, University of Connecticut Health Center, Farmington, Connecticut, USA.
authors.forename: Pamela
authors.initials: P
authors.lastname: Fall
mesh_terms: D000368:Aged; D065635:Benign Paroxysmal Positional Vertigo / Q000097:blood* / Q000503:physiopathology*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D016326:Extracellular Matrix Proteins / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D010037:Otolithic Membrane / Q000378:metabolism* / Q000503:physiopathology; D017698:Postmenopause; D011237:Predictive Value of Tests; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D016326:Extracellular Matrix Proteins; C449659:otolin-1
keywords: benign paroxysmal positional vertigo; biomarker; inner ear; otoconia; otolin; stria vascularis