An update on autoimmune inner ear disease: A systematic review of pharmacotherapy

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.

Genetic control of the dynamic transcriptional response to immune stimuli and glucocorticoids at single-cell resolution

Synthetic glucocorticoids, such as dexamethasone, have been used as a treatment for many immune conditions, such as asthma and, more recently, severe COVID-19. Single-cell data can capture more fine-grained details on transcriptional variability and dynamics to gain a better understanding of the molecular underpinnings of inter-individual variation in drug response. Here, we used single-cell RNA-seq to study the dynamics of the transcriptional response to glucocorticoids in activated peripheral blood mononuclear cells from 96 African American children. We used novel statistical approaches to calculate a mean-independent measure of gene expression variability and a measure of transcriptional response pseudotime. Using these approaches, we showed that glucocorticoids reverse the effects of immune stimulation on both gene expression mean and variability. Our novel measure of gene expression response dynamics, based on the diagonal linear discriminant analysis, separated individual cells by response status on the basis of their transcriptional profiles and allowed us to identify different dynamic patterns of gene expression along the response pseudotime. We identified genetic variants regulating gene expression mean and variability, including treatment-specific effects, and showed widespread genetic regulation of the transcriptional dynamics of the gene expression response.

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 hearing loss and a chance of its development in children: literature review and own observations]

Autoimmune sensorineural hearing loss (AiSNHL) is an uncommon auditory disorder characterized by rapidly progressive bilateral hearing loss and a positive clinical response to treatment with corticosteroids and cytostatics. The prevalence of the disease in the adult population is less than 1% among all cases of subacute and permanent sensorineural hearing loss (precise data are unknown), it is even rarer in children. AiSNHL can be primary (isolated, organ-specific) or secondary (manifestation of another systemic autoimmune disease). The pathogenesis of AiSNHL is based on the proliferation of autoaggressive T cells and the pathological production of autoantibodies to the protein structures of the inner ear, which leads to damage to various parts of the cochlea (possibly also to the retrocochlear parts of the auditory system), less frequently to the vestibular labyrinth. Pathologically, the disease is most often represented by cochlear vasculitis with degeneration of the vascular stria, damage to hair cells and spiral ganglion cells, and endolymphatic hydrops. In 50% of cases, the result of autoimmune inflammation may be fibrosis and/or ossification of the cochlea. The most characteristic symptoms of AiSNHL at any age are episodes of sudden progression of hearing loss, fluctuations of hearing thresholds, and bilateral, often asymmetric impairments. The article presents contemporary ideas of the clinical and audiological manifestations of AiSNHL, the possibilities of diagnosing and treating the disease, and highlights the current approaches to (re)habilitation. Along with literature data, two own clinical cases of an extremely rare pediatric AiSNHL are given.

Role of Inner Ear Macrophages and Autoimmune/Autoinflammatory Mechanisms in the Pathophysiology of Inner Ear Disease

Macrophages play important roles in tissue homeostasis and inflammation. Recent studies have revealed that macrophages are dispersed in the inner ear and may play essential roles in eliciting an immune response. Autoinflammatory diseases comprise a family of immune-mediated diseases, some of which involve sensorineural hearing loss, indicating that similar mechanisms may underlie the pathogenesis of immune-mediated hearing loss. Autoimmune inner ear disease (AIED) is an idiopathic disorder characterized by unexpected hearing loss. Tissue macrophages in the inner ear represent a potential target for modulation of the local immune response in patients with AIED/autoinflammatory diseases. In this review, we describe the relationship between cochlear macrophages and the pathophysiology of AIED/autoinflammatory disease.

Hearing restoration and the stria vascularis: evidence for the role of the immune system in hearing restoration

PURPOSE OF REVIEW

This article reviews the current literature regarding the pathogenesis of immune-mediated sensorineural hearing loss, utilizes previously published single-nucleus transcriptional profiles to characterize cytokine and cytokine receptor expression in the adult stria vascularis cell types to support immune system interaction with the stria vascularis and reviews the current literature on immunomodulatory agents currently being used for hearing-restoration treatment.

RECENT FINDINGS

The literature review highlights recent studies that elucidate many cytokines and immune markers, which have been linked to various immune-mediated disease processes that have been observed with sensorineural hearing loss within the stria vascularis and highlights recent publications studying therapeutic targets for these pathways.

SUMMARY

This review highlights the current literature regarding the pathogenesis of immune-mediated hearing loss. The role of cochlear structures in human temporal bones from patients with immune-mediated sensorineural hearing loss are highlighted, and we review cytokine signalling pathways relevant to immune-mediated sensorineural hearing loss and localize genes encoding both cytokine and cytokine receptors involved in these pathways. Finally, we review immunomodulatory therapeutics in light of these findings and point to opportunities for the application of novel therapeutics by targeting these signalling pathways.

Genetic control of the dynamic transcriptional response to immune stimuli and glucocorticoids at single cell resolution.. [PMID: 35313584 PMCID: PMC8936121 DOI: 10.1101/2021.09.30.462672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Synthetic glucocorticoids, such as dexamethasone, have been used as treatment for many immune conditions, such as asthma and more recently severe COVID-19. Single cell data can capture more fine-grained details on transcriptional variability and dynamics to gain a better understanding of the molecular underpinnings of inter-individual variation in drug response. Here, we used single cell RNA-seq to study the dynamics of the transcriptional response to glucocorticoids in activated Peripheral Blood Mononuclear Cells from 96 African American children. We employed novel statistical approaches to calculate a mean-independent measure of gene expression variability and a measure of transcriptional response pseudotime. Using these approaches, we demonstrated that glucocorticoids reverse the effects of immune stimulation on both gene expression mean and variability. Our novel measure of gene expression response dynamics, based on the diagonal linear discriminant analysis, separated individual cells by response status on the basis of their transcriptional profiles and allowed us to identify different dynamic patterns of gene expression along the response pseudotime. We identified genetic variants regulating gene expression mean and variability, including treatment-specific effects, and demonstrated widespread genetic regulation of the transcriptional dynamics of the gene expression response.

The use of gene-modified bone marrow mesenchymal stem cells for cochlear cell therapy

BACKGROUND

The aim of this study was to investigate the potential of using bone marrow mesenchymal stem cells (BMSCs) for treatment of inflammation and autoimmune sensorineural hearing loss.

METHODS

Fifty-five immunized guinea pigs were divided into five groups. Group A received BMSCs expressing IL-4, group B received BMSCs expressing an empty carrier vector, group C received recombinant lentivirus expressing IL-4, group D received recombinant lentivirus expressing an empty carrier vector, and group E received phosphate-buffered saline. Auditory function was monitored using brain stem responses (ABRs) to evaluate the auditory changes. The distribution of implanted BMSCs in the inner ear was estimated using fluorescence microscopy. The distribution and expression of IL-4 gene products in the inner ear were detected via immunohistochemistry.

RESULTS

After transplantation, the ABR III wave threshold decreased significantly in BMSCs expressing exogenous IL-4 group (group A), BMSCs expressing empty carrier vector group (group B), and recombinant lentivirus expressing IL-4 group (group C) (P < 0.001), which means the auditory functions of the experimental guinea pigs were improved. Further statistical analysis revealed that BMSCs expressing exogenous IL-4 group (group A) and BMSCs expressing empty carrier vector group (group B) were able to improve the auditory function more obviously (P < 0.05). Lentivirus-infected BMSCs were able to migrate to the inner ear. Fluorescence-positive BMSCs were scattered in the scala tympani and vestibule.

CONCLUSIONS

These results demonstrated that BMSCs expressing exogenous IL-4 successfully migrated into the inner ear in an in vitro study. BMSCs expressing exogenous IL-4 and BMSCs can be used to treat inflammatory injury in autoimmune inner ear diseases.

Biologics in Otolaryngology: Past, Present, and Future

Biologics have been widely adopted in multiple subspecialties of otolaryngology. This article provides an overview of past, present, and future uses of biologics in otolaryngology with emphasis on allergic rhinitis, chronic rhinosinusitis with polyposis, head and neck squamous cell carcinoma, salivary and skull base tumors, hearing loss, and other otologic disorders.

Rare Disorders of the Vestibular Labyrinth: of Zebras, Chameleons and Wolves in Sheep's Clothing

The differential diagnosis of vertigo syndromes is a challenging issue, as many - and in particular - rare disorders of the vestibular labyrinth can hide behind the very common symptoms of "vertigo" and "dizziness". The following article presents an overview of those rare disorders of the balance organ that are of special interest for the otorhinolaryngologist dealing with vertigo disorders. For a better orientation, these disorders are categorized as acute (AVS), episodic (EVS) and chronic vestibular syndromes (CVS) according to their clinical presentation. The main focus lies on EVS sorted by their duration and the presence/absence of triggering factors (seconds, no triggers: vestibular paroxysmia, Tumarkin attacks; seconds, sound and pressure induced: "third window" syndromes; seconds to minutes, positional: rare variants and differential diagnoses of benign paroxysmal positional vertigo; hours to days, spontaneous: intralabyrinthine schwannomas, endolymphatic sac tumors, autoimmune disorders of the inner ear). Furthermore, rare causes of AVS (inferior vestibular neuritis, otolith organ specific dysfunction, vascular labyrinthine disorders, acute bilateral vestibulopathy) and CVS (chronic bilateral vestibulopathy) are covered. In each case, special emphasis is laid on the decisive diagnostic test for the identification of the rare disease and "red flags" for potentially dangerous disorders (e. g. labyrinthine infarction/hemorrhage). Thus, this chapter may serve as a clinical companion for the otorhinolaryngologist aiding in the efficient diagnosis and treatment of rare disorders of the vestibular labyrinth.

Sensorineural Hearing Loss and Systemic Autoimmune Disease: The Experience of a Systemic Immune-Mediated Diseases Unit

Background

Autoimmune inner ear disease (AIED) represents less than 1% of all cases of sensorineural hearing loss (SNHL) but its frequency may be underestimated due to lack of specific clinical and laboratory criteria. AIED can be associated with a systemic autoimmune disease (SAID) in 15%-30% of the cases. The objective of the present study was to characterize the clinical and prognostic factors of a cohort of patients with AIED.

Materials and methods

The authors conducted a retrospective descriptive analysis of a cohort of patients with AIED referred from the otorhinolaryngology department to a systemic immune-mediated diseases unit between March 2013 and November 2020. A consecutive sample of 39 patients with suspected AIED was referred. SNHL was defined as a fall of the hearing threshold of at least 30 decibels in three consecutive frequencies. Eight patients were excluded for not meeting the audiometric criteria or having confounding factors. The remaining 31 patients were included with a total of 50 affected ears. To classify the intensity of hearing loss, an arithmetic mean of pure tone was calculated. Normal hearing or mild hearing loss at the last pure tone audiometry of the follow-up were an indicator of good prognosis and were considered the outcome of interest.

Results

Thirty-two percent of the patients had an associated SAID. There were no differences regarding demographic and clinical characteristics when comparing patients with AIED alone and patients with AIED and a SAID, except for the positivity of antinuclear antibodies (ANA). ANA positivity was superior in patients with the association of AIED and a SAID when compared with patients with AIED alone (90% vs 50%; p=0.037). The SAID was diagnosed after the AIED in 70% of the patients, in which diagnosis of the SAID occurred a median of 4,2 (IQR 0.8-5.1) years after the diagnosis of the AIED. Normal audiometric evaluation or a mild hearing loss was achieved in 31% of the ears at the last audiometric evaluation. A normal audiometry or a mild hearing loss at the time of diagnosis was independently associated with a better outcome (31%, 14%, CI 1.71-273.69; p=0.018). Bilateral hearing loss was independently associated with a worse outcome (54%, 79%, CI 0.01-0.84; p=0.035). The use of systemic corticosteroids (p=0.941), transtympanic corticosteroids (p=0.700) and non-steroid immunomodulator drugs (p=0.986) did not affect prognosis. The presence of a SIAD did not affect the prognosis (p=0.986).

Conclusions

In this cohort, SAID was present in one-third of the patients with AIED. A good prognosis was achieved in one-third of the patients. A normal audiometry or mild disease at presentation was associated with a good outcome, whilst bilateral involvement was associated with a bad one. Association of a SAID did not seem to influence the hearing-related prognosis. Positivity of ANA antibodies may justify performing a complementary investigation to determine the presence of a SAID.

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.