Comparison of IL-1 Receptor Antagonist and Dexamethasone in Noise-Induced Hearing Loss: Animal Model

Objective: This study aimed to attenuate cochlear inflammation following noise-induced hearing loss by targeting IL-1. We evaluated the effectiveness of IL-1 inhibition through auditory and histological assessments in an animal model.

Study design: Experimental animal study.

Setting: Gazi University Faculty of Medicine, Ankara, Turkey.

Methods: Twenty-four rats were randomly assigned into 3 groups: Anakinra, dexamethasone, and control groups. All animals were exposed to broadband noise (110 dB SPL, 8 hours), auditory brainstem response (ABR) tests were conducted before noise exposure, immediately after, and on Day 14. Anakinra, dexamethasone, and saline were administered intraperitoneally, cochlear tissues were harvested for histological and immunohistochemical evaluation.

Results: On Day 14, ABR thresholds in Anakinra group were better than the control group across all frequencies, with a significant difference observed at 8 kHz (P = .036). The mean number of OHC was significantly higher in Anakinra group compared to the control group (P < .05). The mean number of IHC in the Anakinra group was greater than in the dexamethasone group. IL-1β immunopositivity in the stria vascularis and spiral ganglia was significantly higher in Anakinra group compared to dexamethasone group (P = .022 and P = .013, respectively). TNF-α immunopositivity in the stria vascularis and spiral ganglia was significantly greater in control group than in Anakinra group (P = .037 and P = .01, respectively).

Conclusion: The comparable efficacy of Anakinra and dexamethasone in both histological and auditory assessments suggests that Anakinra may serve as a promising therapeutic option for noise-induced hearing loss.