Effect of omalizumab on biomarkers in middle ear effusion in patients with eosinophilic otitis media

Conclusions: Eosinophil cationic protein (ECP) concentrations in middle ear effusion (MEE) in patients with eosinophilic otitis media (EOM) were significantly decreased at 3 months after the administration of omalizumab from the baseline level (p < 0.05). This study provides new evidence that omalizumab reduces eosinophilic inflammation in the middle ear and that the reduction of ECP may not be caused by suppression of interleukin (IL)-5 production in the middle ear mucosa. Objective: EOM is an intractable otitis media characterized by a highly viscous effusion containing eosinophils. We recently reported that anti-IgE therapy using omalizumab was efficacious in the treatment of EOM. To clarify the underlying mechanism, we determined changes in biomarkers in MEE related to eosinophilic inflammation after therapy. Methods: Nine patients with EOM received the anti-IgE agent omalizumab for 3 months. Among them, five patients continued anti-IgE therapy for longer than 1 year. Eight EOM patients without administration of omalizumab were also included in the study as controls. The concentrations of eosinophilic inflammatory markers such as ECP, IgE, IL-4, and IL-5 in MEE were measured before and after the administration of omalizumab. Results: After 3 months of omalizumab therapy, the ECP concentration in MEE was significantly reduced from the baseline level (p < 0.05), while no significant change of ECP in the serum was observed. The concentrations of IL-4 and IL-5 in MEE showed no significant change before and after the therapy in EOM patients treated with omalizumab.