Case-control study of otoconia proteins otolin-1 and otoconin-90 in patients with Meniere's disease.

Backgrounds: Otolin-1 and otoconin-90, the main otoconia matrix protein, can pass through the labyrinth-blood barrier and are detectable in the peripheral blood. Previous studies have shown that serum levels of these proteins well reflect otolith status, but none of concerning Meniere's disease (MD).

Objectives: This study aimed to evaluate the serum levels of otolin-1 and otoconin-90 in patients with MD.

Material and methods: Patients with MD confirmed during an acute episode, and age- and sex-matched controls were recruited. Their demographic and clinical data were recorded. The serum levels of otolin-1 and otoconin-90 were measured and compared.

Results: A total of 33 patients with MD and 176 healthy controls were recruited. In patients with MD, the median otolin-1 level was 284.96 pg/mL (interquartile range [IQR] 208.65-331.49 pg/mL) and the median otoconin-90 level was 60.50 ng/mL (IQR 40.61-85.62 ng/mL), which were significantly higher than those in the control group (p < 0.0001 and p = 0.005, respectively). Among patients with MD, serum otoconin-90 levels were correlated with the MD clinical grade (ρ = 0.487, p = 0.04), whereas serum otoconin-1 levels were not (ρ = 0.327, p = 0.063).

Conclusions: Serum levels of otolin-1 and otoconin-90 may serve as biomarkers of otolith lesions in patients with MD.