Identification of blood-based inflammatory biomarkers for vestibular neuritis using a proximity extension assay

ObjectiveThe present study aimed to identify blood-based inflammatory biomarkers that would help investigate the underlying pathogenesis in vestibular neuritis (VN) using a proximity extension assay (PEA).MethodsIn this single-center prospective study, we enrolled both a cross-sectional (acute VN vs normal controls) and a longitudinal (acute phase vs recovery phase) cohorts. We quantified 92 plasma inflammatory proteins using the Olink PEA and identified differentially expressed proteins (DEPs) in each cohort using t-tests. The clinical utility and predictive value of each DEP were evaluated using the Pearson correlation test and receiver operating characteristic (ROC) curve analysis, respectively.ResultsIn the cross-sectional cohort, there were 17 DEPs identified between acute VN (n = 35) and normal controls (n = 35), of which Flt3L was the only downregulated DEP that showed longitudinal changes congruent with clinical disease activity in the longitudinal cohort (n = 18). The correlation analysis revealed that the expression level of CXCL5 was significantly related to the absolute gain and gain asymmetry of the horizontal vestibulo-ocular reflex, while five DEPs (OSM, Flt3L, IFN-γ, MCP-1, and uPA) were negatively correlated with the hospitalization period. ROC curves showed that CXCL1 and Flt3L were upregulated and downregulated DEPs with high predictive values, respectively.ConclusionsThis study shows that the high-throughput PEA technology can be used to identify blood-based inflammatory biomarkers for VN. Our findings highlight the potential value of Flt3L and CXCL1/CXCL5 as objective VN markers that may correlate with disease activity.