Autoimmune inner ear disease preliminary case report: audiometric findings following steroid treatments

Relapsing autoimmune inner ear disease with significant response to methotrexate and azathioprine combination therapy: A case report and mini literature review

RATIONALE

Autoimmune inner ear disease typically presents with bilateral hearing loss that progresses over weeks or months though its mechanisms are unknown. Corticosteroids are the first-line treatment, but their responses are variable and relapses are frequent. Thus, many experts have sought to replace corticosteroids with immunosuppressive agents.

PATIENT CONCERNS

A 35-year-old woman experienced a progressive hearing impairment, initially on the left side and later becoming bilateral. Her response to corticosteroid monotherapy was temporary, and there have been two relapse episodes over several months.

DIAGNOSES

Autoimmune inner ear disease was considered due to evidence of autoimmunity combined with a clinical course of bilateral and recurrent sensorineural hearing loss and a partial response to corticosteroid therapy.

INTERVENTIONS

The patient received a 3-day mini-pulse of methylprednisolone at 250 mg/d, followed by 12 mg/d maintenance, and concurrently began an azathioprine regimen gradually increasing to 100 mg/day as a corticosteroid-sparing agent.

OUTCOMES

Three weeks after immunosuppressive therapy, hearing and pure-tone audiometry improved, and after 7 weeks, methylprednisolone was tapered to 8 mg/d. The dosage was further reduced by adding methotrexate at 7.5 mg/week, resulting in a reduction to 4 mg/d as maintenance therapy after 4 weeks.

LESSONS

For patients who are unresponsive to corticosteroids or experience difficulty tolerating them, a combination therapy of methotrexate and azathioprine is recommended as a viable alternative as this regimen is well-tolerated and yields positive outcomes.

Sex differences in autoimmune inner ear disease treatment and audiological outcomes

OBJECTIVE

The primary objective of this study was to assess possible sex-related differences in AIED treatment. The secondary aim was to assess the long-term outcomes of treatment using pre- and post-treatment audiometry and speech discrimination scores.

METHODS

Adult patients with a diagnosis of AIED who were treated for their condition at the senior author's (RTS) practice from 2010 to 2022 were included in this study. Patients were grouped as males or females for further analysis and comparison. Data included past medical history, medication use, surgical history and social history. Air-conduction thresholds (500 to 8000 Hz) were collected and averaged into discrete variables for pre- and post-treatment. The change (∆) and percent change (%∆) of these variables following therapy were analyzed. Speech discrimination score (SDS) testing results were taken at the same time points as pure tone averages, and patients were sub-stratified based on evidence of improvement in SDS and compared accordingly.

RESULTS

One hundred eighty-four patients (78 male/106 female) were included in this study. The mean age of the male participants was 57.18 ± 15.92 years, and the mean age of the female participants was 53.49 ± 16.04 years (p = 0.220). Comorbid autoimmune disease (AD) was more prevalent in females than in males (38.7 % vs. 16.7 %, p = 0.001). Of the patients treated with oral steroids, females received significantly more courses than males (2.554 ± 2.078 vs. 1.946 ± 1.301, p = 0.020). However, the average duration of oral steroids used per trial did not differ significantly between males and females (21.02 ± 18.05 vs. 20.62 ± 7.49, p = 0.135). Audiological results demonstrated that the change (∆) in pure tone average (PTA) at 0.5, 1, 2, and 3 kHz (-4.21 ± 6.394 vs. -3.91 ± 6.105) and high-frequency pure tone average (HFPTA) at 4, 6, and 8 kHz (-4.55 ± 6.544 vs. -2.19 ± 6.842) was not significantly different between the sexes following treatment (p = 0.376 and p = 0.101, respectively). Similarly, the percentage change (%∆) in PTA (-13.17 % vs. -15.01 %) and HFPTA (-8.50 % vs. -6.76 %) also did not differ significantly between males and females (p = 0.900 and p = 0.367, respectively). One hundred-five (57.1 %) patients qualified for the SDS improvement subgroup for analysis, with 50 (47.6 %) being male and 55 (51.9 %) being female (p = 0.159). The change (∆) in SDS (15.12 ± 21.159 vs. 10.62 ± 19.206) and the percentage change (%∆) in SDS (16.71 % vs. 12.40 %) also showed no significant difference between male and female patients (p = 0.312 and p = 0.313, respectively).

CONCLUSION

AIED is not a uniform condition regarding clinical presentation, audiological findings or progression, nor is its treatment straightforward. The utilization and duration of cytotoxic medications, as well as PTA and SDS findings, did not differ between the sexes. However, significantly more courses of oral steroids were prescribed to females than males. Sex as a biological variable and its implications in the pathogenesis and treatment of AIED warrant further study.

Autoimmune inner ear disease: A systematic review of management

OBJECTIVES

The study systematically reviewed the existing literature on the management of autoimmune inner ear disease (AIED).

STUDY DESIGN

Systematic review.

METHODS

We performed a literature search of Embase, NCBI, Cochrane, and Web of Science databases from April 1990 to April 2020. Inclusion criteria included studies that were retrospective or prospective in nature evaluating the treatment of AIED with audiometric data measuring hearing outcomes during treatment. Hearing improvement was the primary study outcome and improvement in vestibular symptoms was the secondary study outcome.

RESULTS

Sixteen of 412 candidate articles were included in our study. Systemic steroid treatment is most commonly described. Alternative treatment modalities included intratympanic steroid treatment, methotrexate, cyclophosphamide, azathioprine, infliximab, etanercept, adalimumab, golimumab, methylprednisolone, rituximab, and anakinra.

CONCLUSION

Systemic corticosteroids are the first line treatment of AIED. Intratympanic steroids are a potential adjuvant or alternative treatment for patients who cannot tolerate or become refractory to steroid treatment. Steroid nonresponders may benefit from biologic therapy. Alternative treatment modalities including nonsteroidal immunosuppressants and biologics have been studied in small cohorts of patients with varying results. Prospective studies investigating the efficacy of biologic and nonsteroidal therapy are warranted.

LEVEL OF EVIDENCE

2.

Azathioprine reduces the risk of audiometric relapse in immune-mediated hearing loss

INTRODUCTION

Current schemes for treatment of immune-mediated hearing loss with sporadic short-course, low-dose corticosteroids, are insufficient.

METHODS

To determine the role of azathioprine in the control of auditory impairment, a longitudinal, observational, descriptive study was performed with 20 patients treated with azathioprine (1.5-2.5mg/kg/day into two doses) for 1year. The loss of 10dB on two consecutive frequencies or 15dB on an isolated frequency was considered as relapse.

RESULTS

The mean age of the patients was 52.50years (95%CI: 46.91-58.17), half were women. Bilateral affectation was 65%. 75% had organ specific disease and 25% had systemic autoimmune disease. The difference between baseline PTA (46.49dB; DS18.90) and PTA at 12months (45.47dB; DS18.88) did not reach statistical significance (P=.799). There was a moderate positive correlation between female sex and the presence of systemic disease (R=.577). By applying Student's t for paired data, a significant difference (P=.042) was obtained between the PTA in frequencies up to 1000 Hz (PTA125-1000Hz). The relative incidence rate of relapse per year was .52 relapses/year (95%CI: .19-1.14]). The median time to audiometric relapse-free was 9.70months (DS1.03).

CONCLUSIONS

Azathioprine maintains the hearing threshold, decreases the risk of relapse, and slows down the rate at which patients relapse, altering the course of immune-mediated inner ear disease.

Evaluation of a transtympanic delivery system in Mus musculus for extended release steroids

OBJECTIVE

The current investigation evaluated a novel extended release delivery system for treating inner ear diseases. The platform technology consists of a film forming agent (FFA) and microsphere component to localize and extend drug delivery within the ear.

STUDY DESIGN

Studies evaluated dissolution kinetics of microspheres with multiple encapsulates, testing of a variety of FFAs, and ability to localize to the round window membrane in mice in vivo.

SETTING

Studies were completed at Orbis Biosciences and The University of Kansas Medical Center.

SUBJECTS

In conjunction with in vitro characterization, an infrared dye-containing microsphere formulation was evaluated for round window membrane (RWM) localization and general tolerability in C57/BL6 Mus musculus for 35 days.

METHODS

In vitro characterization was performed using upright diffusion cells on cellulose acetate membranes, with drug content quantified by high performance liquid chromatography. Mus musculus dosing of infrared dye-containing microspheres was performed under anesthesia with a 27 GA needle and 2.0 μL injection volume RESULTS: In vitro dissolution demonstrates the ability of the FFA with microsphere platform to release steroids, proteins, peptides, and nucleic acids for at least one month, while necroscopy shows the ability of the FFA with dye-loaded microspheres to remain localized to Mus musculus RWM for the same period of time, with favorable tolerability.

CONCLUSIONS

Combining FFA and microsphere for localized drug delivery may enable cost-effective, extended release local delivery to the inner ear of new and existing small molecules, proteins, peptides, and nucleic acids.

An open label study to evaluate the safety and efficacy of intratympanic golimumab therapy in patients with autoimmune inner ear disease

OBJECTIVE

To evaluate the safety and efficacy of intratympanically injected golimumab (GLM), a TNF-α inhibitor, as a steroid-sparing agent for patients with steroid-dependent autoimmune inner ear disease (AIED).

STUDY DESIGN

Open label.

SETTING

Tertiary referral center.

PATIENTS

Ten patients with steroid-dependent AIED were enrolled in Stage 2. The average patient age at enrollment was 59, with an average of 12.5 years from the start of bilateral hearing loss symptoms. The average dose of daily prednisone at the start of injections was 18 mg.

INTERVENTION

Intratympanic injection of GLM.

MAIN OUTCOME MEASURE

Hearing loss progression (treatment failure) was defined as either an increase in pure-tone thresholds by frequency or a decrease in word recognition score.

RESULTS

There were no serious adverse events. Five of seven per-protocol subjects experienced stable pure-tone thresholds in the injected ear, whereas 4 had stable word recognition scores. Two subjects experienced an improvement in word recognition scores. The results support the hypothesis that GLM may be a promising treatment.

CONCLUSIONS

The TNF-α inhibitor GLM stabilized hearing in 3 of 7 per-protocol subjects with AIED and allowed a complete tapering off of prednisone in those 7 subjects. Studies with larger samples sizes are warranted.