Mechanisms underlying autoimmune inner ear disease

Prevalence of hearing loss, tinnitus, vertigo and sudden deafness among patients with polymyositis and dermatomyositis

Little is known about a possible association of autoimmune inner ear disease among patients diagnosed with polymyositis (PM)/dermatomyositis (DM). This study aimed to explore differences in the prevalence of inner ear symptoms among patients with and without PM/DM using a nationwide population-based dataset. Data for this study were retrieved from the Taiwan National Health Insurance Research Database. The study sample included 1622 patients diagnosed with PM/DM and 8109 propensity-score matched comparison patients without PM/DM. We performed multivariate logistic regressions to calculate odds ratios (ORs) and 95% confidence interval (CI) for tinnitus, hearing loss, sudden deafness, and vertigo among patients with PM/DM versus comparison patients. Chi-square tests showed statistically significant differences between patients with PM/DM and comparison patients in the prevalence of tinnitus (16.1% vs. 12.7%, p < 0.001), non-conductive hearing loss (9.2% vs. 6.8%, p < 0.001), and vertigo (14.4% vs. 11.1%, p < 0.001). The adjusted ORs for tinnitus, non-conductive hearing loss, and vertigo, respectively, were 1.332 (95% CI = 1.147-1.547), 1.399 (95% CI = 1.154-1.696), and 1.374 (95% CI = 1.173-1.611) for patients with PM/DM when compared to comparison patients. Our study finds that patients with PM/DM have higher prevalence rates of tinnitus, non-conductive hearing loss, and vertigo than comparison patients.

Secondary autoimmune immune ear disease (AIED): a systematic review and meta-analysis on vestibular manifestations of systemic autoimmune and inflammatory disorders

Secondary autoimmune inner ear disease (AIED) is often bilateral and asymmetric in patients presenting with audiovestibular symptoms due to a systemic autoimmune disease. This systematic review and meta-analysis are aimed at identifying and highlighting patterns in prevalence of vestibular dysfunction, symptom presentation, and diagnostic methods in extant literature by combining clinical context from case reports with quantitative analyses from cohort studies. Screening of articles by title, abstract, and full text was completed by four reviewers (K.Z., A.L., S.C., and S.J.). In this study, we grouped secondary AIED and systemic autoimmune diseases by pathophysiologic mechanism: (1) connective tissue disease (CTD), (2) vasculitides (VAS), (3) systemic inflammatory disorders (SID), and (4) other immune-mediated disorders (OIMD). The search for AIED disease identified 120 articles (cohorts and case reports) that met the final inclusion criteria. All 120 were included in the qualitative review, and 54 articles were included for meta-analysis. Of these 54 articles, 22 included a control group (CwC). Ninety individual cases or patient presentations from 66 articles were included for analysis in addition to the 54 cohort articles. Secondary AIED does not have a diagnostic algorithm for managing vestibular symptoms. The management of audiovestibular symptoms requires close collaboration between otolaryngologists and rheumatologists to preserve end-organ function of the ear. To improve our ability to understand the impact on the vestibular system, vestibular clinicians need to develop a standardized reporting method. Clinical presentation should frequently be paired with vestibular testing to contextually investigate symptom severity and provide higher quality care.

Autoimmune Inner Ear Disease among Patients with Selective IgA Deficiency

OBJECTIVES

Autoimmune inner ear disease (AIED) is a distinct clinical entity from sudden sensorineural hearing loss. The purpose of this study was to investigate the clinical characteristics of AIED in patients with selective IgA deficiency (sIgAD).

MATERIALS AND METHODS

This retrospective observational study was based on data from the Leumit Healthcare Services database in Israel. We searched all subjects aged ≥12 years who had undergone serum total IgA measurements during 2004-2014 for any reason. The sIgAD patients included all subjects with serum IgA of ≤7 mg/dL (0.07 g/L). A control group was randomly sampled from the full study population (n ≈ 730,000) with a case-control ratio of 10 controls for each case (1:10).

RESULTS

Among 347 subjects with sIgAD, we identified 9 patients with concomitant AIED (sIgAD + AIED group). This group was characterized by a higher prevalence of allergic diseases (8 patients; 88.9%) than sIgAD patients without AEID (sIgAD + AIED group; 153 patients; 45.2%; p = 0.014). Both systemic diseases (3 patients; 33.3%) and organ-specific autoimmune diseases (7 patients; 77.8%) were more prevalent in the sIgAD + AIED group (sIgAD + AIED group: 19 patients 5.5%, p = 0.015; sIgAD - AEID group: 76 patients, 21.9%, p < 0.001), with an OR of 8.39 (1.94-36.19; p = 0.004). sIgAD patients with and without AIED were characterized by a higher prevalence of documented episodes of acute otitis media, allergic diseases, and autoimmune diseases than the control group.

CONCLUSION

The study exposes a significant association between AIED and sIgAD. We believe that sIgAD has to be excluded in AIED patients.

miR‑10b‑3p, miR‑8112 and let‑7j as potential biomarkers for autoimmune inner ear diseases

Circulating microRNAs (miRNAs) have been suggested as non‑invasive biomarkers for the diagnosis of several autoimmune diseases. However, to the best of our knowledge, no studies have yet examined the miRNA expression profiles in autoimmune inner ear disease (AIED). The present study aimed to use an miRNA sequencing assay to detect the miRNA expression profiles of serum samples from 3 control mice and 3 antigen‑induced AIED model mice. Differentially expressed miRNAs (DE‑miRNAs) were screened using a t‑test. miRNA target prediction was performed using TargetScan Mouse. Then, the miRNA‑target gene interaction network was constructed and visualized using Cytoscape software. The underlying functions of the target genes of the DE‑miRNAs were predicted using the clusterProfiler package. As a result, 22 miRNAs were identified as DE‑miRNAs between AIED and control mice, including 10 upregulated and 12 downregulated genes. Based on the TargetScan Mouse prediction, 1,958 genes were identified as the targets for the 22 DE‑miRNAs. Functional analysis indicated that only the target genes of 8 miRNAs were respectively enriched for Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways, among which miR‑10b‑3p, let‑7j and miR‑8112 were shared between the two pathway analyses. These 3 miRNAs may be involved in AIED by affecting inflammatory chemokine (miR‑10b‑3p‑C‑C motif chemokine 12), Wnt signaling (miR‑8112‑Wnt9b/Wnt 3a/Wnt2b) and Mucin type O‑glycan biosynthesis pathways (let‑7j‑Galnt2/Galnt12). In conclusion, miR‑10b‑3p, miR‑8112 and let‑7j may be underlying biomarkers for diagnosing AIED.

Screening of genes associated with inflammatory responses in the endolymphatic sac reveals underlying mechanisms for autoimmune inner ear diseases

The current study analyzed gene expression profiles of the endolymphatic sac (ES) in rats and identified expressed genes, present in the human and rat ES, to reveal key hubs for inflammatory responses. Microarray data (accession no. E-MEXP-3022) were obtained from the European Bioinformatics Institute database, including three biological replicates of ES plus dura tissues and three replicates of pure dura tissues form rats. Differentially expressed genes (DEGs) were screened using the Linear Model for Microarray data method and a protein-protein interaction (PPI) network was constructed using data from the Search Tool for the Retrieval of Interacting Genes/Proteins database followed by a module analysis via Clustering with Overlapping Neighborhood Expansion. Function enrichment analysis was performed using the Database for Annotation, Visualization and Integrated Discovery online tool. A total of 612 DEGs were identified, including 396 upregulated and 216 downregulated genes. Gene ontology term enrichment analysis indicated DEGs were associated with cell adhesion, including α5-integrin (Itga1) and secreted phosphoprotein 1 (Spp1); T cell co-stimulation, including C-C chemokine ligand (Ccl)21 and Ccl19; and the toll-like receptor signaling pathway, including toll-like receptor (Tlr)2, Tlr7 and Tlr8. These conclusions were supported by Kyoto Encyclopedia of Genes and Genomes pathway analyses revealing extracellular matrix-receptor interaction, including Itga1 and Spp1; leukocyte transendothelial migration, includingclaudin-4 (Cldn4); and malaria, including Tlr2. The hub roles of Itga1, Cd24 and Spp1 were revealed by calculating three topological properties of the PPI network. Ccl21, Ccl19 and Cldn4 were demonstrated to be crucial following significant module analysis according to the corresponding threshold, which revealed they were enriched in inflammation pathways. Tlr7, Tlr2, granzyme m and Tlr8 were common genes associated with inflammatory responses in rat and human ES. In conclusion, abnormal expression of the aforementioned inflammation-associated genes may be associated with the development of autoimmune inner ear diseases.

The Role of Autoimmunity in the Pathogenesis of Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss (SSHL) is a clinically common acute symptom in otolaryngology. Although the incidence of SSHL has increased around the world in recent years, the etiology of the disease is still unclear. It has been reported that infections, ototoxic drugs, membrane labyrinth rupture, carcinomas, circulatory system diseases, autoimmune diseases, brain lesions, mental diseases, congenital or inherited diseases, and so on, are all risk factors for SSHL. Here, we discuss the autoimmune mechanisms behind SSHL, which might be induced by type II–IV allergic reactions. We also introduce the main immunosuppressive medications that have been used to treat SSHL, which will help us to identify potential targets for immune therapy.

Autoimmune inner ear disease: a retrospective review of forty-seven patients

The purpose of this retrospective study was to characterize and further define autoimmune inner ear disease (AIED) using the Harris AIED classification. A retrospective review was conducted at two tertiary medical centers for 47 patients who were diagnosed with AIED. The overall patient response rate to oral prednisone treatment was 69.7%. The sensitivity of the test for a serum antibody against heat-shock protein 70 (HSP70) was 54.5% and the specificity was 42.9%. Therefore, the clinical utility of the HSP70 antibody test appeared to be limited with respect to the diagnosis of AIED. Vertigo, tinnitus and aural fullness improved significantly with both of the newly developed adalimumab (Humira®) and rituximab (Rituxan®). However, hearing loss did not improve in the present study.