Masaki Tatsuya

Background: Eosinophilic chronic rhinosinusitis (ECRS) is generally characterized by refractory type 2 inflammation along with severe asthma. Although tezepelumab, an anti-thymic stromal lymphopoietin (TSLP) monoclonal antibody, has broad efficacy in severe asthma, its effects on sinonasal inflammation in ECRS remain unclear. In this retrospective observational study, we investigated the radiological and clinical changes in patients with ECRS and severe asthma treated with tezepelumab. Methods: Clinical data, blood eosinophil counts, fractional exhaled nitric oxide (FeNO), total serum IgE levels, lung function, and paranasal sinus CT findings of seven patients with ECRS who received tezepelumab for comorbid severe asthma at a single tertiary care center between 2022 and 2024, were collected. Radiologic severity was assessed using the Lund-Mackay score (LMS) at baseline and ≥6 months after treatment initiation. Results: The median LMS showed a trend toward reduction from baseline to ≥6 months, although this difference did not reach statistical significance (p = 0.051). In contrast, blood eosinophil counts, serum IgE levels, FeNO levels, and the FEV_1/FVC ratio did not show statistically significant changes during the observation period. Conclusion: Tezepelumab therapy showed a trend toward reduction in the Lund-Mackay score in patients with ECRS and severe asthma, although statistical significance was not reached. Systemic biomarkers and lung function remained stable.

Vestibular hair cells are susceptible to damage from various stimuli such as infections, ischemia, and certain therapeutic drugs, including aminoglycoside antibiotics and the antineoplastic agent cisplatin. In mammals, damage to the vestibular hair cells is permanent. This study aimed to evaluate the protective effects of nobiletin (NOB) against aminoglycoside-induced hair cell death using utricles collected from adult mice. The utricles removed from CBA/N mice were assigned to eight groups according to the dose of NOB and the administration or not of neomycin. Hair cells in the utricles were counted by double labeling with calmodulin and calbindin. NOB inhibited hair cell death in utricles exposed to neomycin. The protective effect of NOB on hair cells in the utricles was also suggested to have resulted from the inhibition of the production and accumulation of 4-hydroxy-2-nonenal, the final product of lipid peroxide aldehyde. NOB suppressed neomycin-induced hair cell death. The principle of hair cell protection from aminoglycoside-induced hair cell death suggests that NOB inhibits reactive oxygen species formation in the utricles exposed to neomycin.