Multiomic-based immune response profiling in migraine, vestibular migraine and Meniere's disease.

Migraine (MI) is the most common neurological disease, affecting with 20% of the world population. A subset of 25% of MI patients showcase concurrent vestibular symptoms, which may classify as vestibular migraine (VM). Meniere's disease (MD) is a complex inner ear disorder defined by episodes of vertigo associated with tinnitus and sensorineural hearing loss with a significant autoimmune/autoinflammatory contribution, which symptoms overlap with VM. Blood samples from 18 patients with MI (5), VM (5) and MD (8) and 6 controls were collected and compared in a case-control study. Droplet-isolated nuclei from mononuclear cells used to generate scRNAseq and scATACseq data sets from MI, VM and MD. MI and VM have no differences in their immune transcriptome; therefore, they were considered as a single cluster for further analyses. Natural Killer (NK) cells transcriptomic data support a polarisation triggered by Type 1 innate immune cells via the release of interleukin (IL)-12, IL-15 and IL-18. According to the monocyte scRNAseq data, there were two MD clusters, one inactive and one driven by monocytes. The unique pathways of the MI + VM cluster were cellular responses to metal ions, whereas MD monocyte-driven cluster pathways showed responses to biotic stimuli. MI and MD have different immune responses. These findings support that MI and VM have a Type 1 immune lymphoid cell response, and that there are two clusters of MD patients, one inactive and one Monocyte-driven.

An overload of missense variants in the OTOG gene may drive a higher prevalence of familial Meniere disease in the European population.

Meniere disease is a complex inner ear disorder with significant familial aggregation. A differential prevalence of familial MD (FMD) has been reported, being 9-10% in Europeans compared to 6% in East Asians. A broad genetic heterogeneity in FMD has been described, OTOG being the most common mutated gene, with a compound heterozygous recessive inheritance. We hypothesize that an OTOG-related founder effect may explain the higher prevalence of FMD in the European population. Therefore, the present study aimed to compare the allele frequency (AF) and distribution of OTOG rare variants across different populations. For this purpose, the coding regions with high constraint (low density of rare variants) were retrieved in the OTOG coding sequence in Non-Finnish European (NFE).. Missense variants (AF < 0.01) were selected from a 100 FMD patient cohort, and their population AF was annotated using gnomAD v2.1. A linkage analysis was performed, and odds ratios were calculated to compare AF between NFE and other populations. Thirteen rare missense variants were observed in 13 FMD patients, with 2 variants (rs61978648 and rs61736002) shared by 5 individuals and another variant (rs117315845) shared by two individuals. The results confirm the observed enrichment of OTOG rare missense variants in FMD. Furthermore, eight variants were enriched in the NFE population, and six of them were in constrained regions. Structural modeling predicts five missense variants that could alter the otogelin stability. We conclude that several variants reported in FMD are in constraint regions, and they may have a founder effect and explain the burden of FMD in the European population.

Epidemiology and genetics of Meniere's disease.

PURPOSE OF REVIEW: This review discusses the recent developments on the understanding of epidemiology and genetics of Meniere's disease. RECENT FINDINGS: Meniere's disease has been shown to be associated with several comorbidities, such as migraine, anxiety, allergy and immune disorders. Recent studies have investigated the relationship between environmental factors and Meniere's disease such as air pollution, allergy, asthma, osteoporosis or atmospheric pressure, reporting specific comorbidities in East Asian population. The application of exome sequencing has enabled the identification of genes sharing rare missense variants in multiple families with Meniere's disease, including OTOG and TECTA and suggesting digenic inheritance in MYO7A . Moreover, knockdown of DTNA gene orthologue in Drosophila resulted in defective proprioception and auditory function. DTNA and FAM136A knockout mice have been studied as potential mouse models for Meniere's disease. SUMMARY: While it has attracted emerging attention in recent years, the study of Meniere's disease genetics is still at its early stage. More geographically and ethnically based human genome studies, and the development of cellular and animal models of Meniere's disease may help shed light on the molecular mechanisms of Meniere's disease and provide the potential for gene-specific therapies.

Phenotypic spectrum of tinnitus patients bearing rare ANK2 gene variants.

PURPOSE: To describe the clinical, audiological, and psychometric features observed in patients with chronic tinnitus and rare variants in the ANK2 gene. METHODS: We report a case series of 12 patients with chronic tinnitus and heterozygous variants in the ANK2 gene. Tinnitus phenotyping included audiological (standard and high-frequency audiometry, Auditory Brainstem Responses (ABR) and Auditory Middle Latency Responses (AMLR)), psychoacoustic and psychometric assessment by a Visual Analog Scale (VAS) for tinnitus annoyance, the Tinnitus Handicap Inventory (THI), the test on Hypersensitivity to Sound (THS-GÜF), the Patient Health Questionnaire (PHQ-9), the Hospital Anxiety and Depression Scale (HADS) and the Montreal Cognitive Assessment (MoCA). RESULTS: All patients reported a persistent, unilateral noise-type tinnitus, mainly described as white noise or narrowband noise. Seven patients (58%) were considered to have extreme phenotype (THI score > 76), and all patients reported some degree of hyperacusis (THS-GÜF score > 18 in 75% of patients). Seven patients scored MoCA < 26, regardless of the age reported, suggesting a mild cognitive disorder. ABR showed no significant differences in latencies and amplitudes between ears with or without tinnitus. Similarly, the latencies of Pa, Pb waves, and NaPa complex in the AMLR did not differ based on the presence of tinnitus. However, there were statistical differences in the amplitudes of Pa waves in AMLR, with significantly greater amplitudes observed in ears with tinnitus. CONCLUSION: Patients with ANK2 variants and severe tinnitus exhibit an endophenotype featuring hyperacusis, persistent noise-like tinnitus, high-frequency hearing loss, and decreased amplitudes in AMLR. However, anxiety, depression, and cognitive symptoms vary among individuals.

Treatment of Meniere's disease with simultaneous triple semicircular canal occlusion and cochlear implantation.

OBJECTIVE: Report three cases of simultaneous triple semicircular canal occlusion (TSCO) and cochlear implantation (CI) as the treatment of intractable Meniere's disease (MD). CASE REPORTS: Patients with MD can present occasionally with intractable vertigo and profound sensorineural hearing loss (SNHL). TSCO and CI have been proposed to control vertigo and restore profound deafness in patients with MD separately. However, a few studies have reported simultaneous TSCO and CI in the same surgical procedure for the treatment of MD. In the present study, we described three patients with MD showing incapacitating vertigo and severe SNHL who underwent simultaneous TSCO and CI after examinations of auditory system, vestibular system, and imaging. Their symptoms were significantly alleviated during the follow-up period. CONCLUSION: The combined TSCO and CI remains a viable treatment option which is effective for the control of vertigo as well as the restoring of hearing in patients with MD.

Single-cell immune profiling of Meniere Disease patients.

BACKGROUND: Meniere Disease (MD) is an inner ear syndrome, characterized by episodes of vertigo, tinnitus and fluctuating sensorineural hearing loss. The pathological mechanism leading to sporadic MD is still poorly understood, however an allergic inflammatory response seems to be involved in some patients with MD. OBJECTIVE: Decipher an immune signature associated with the syndrome. METHODS: We performed mass cytometry immune profiling on peripheral blood from MD patients and controls. We analyzed differences in state and differences in abundance of the different cellular subsets. IgE levels were quantified through ELISA on supernatant of cultured whole blood. RESULTS: We have identified two clusters of individuals according to the single cell cytokine profile. These clusters presented differences in IgE levels, immune cell population abundance, including a reduction of CD56dim NK-cells, and changes in cytokine expression with a different response to bacterial and fungal antigens. CONCLUSION: Our results support a systemic inflammatory response in some MD patients that show a type 2 response with allergic phenotype, which could benefit from personalized IL-4 blockers.

CSVS, a crowdsourcing database of the Spanish population genetic variability.

The knowledge of the genetic variability of the local population is of utmost importance in personalized medicine and has been revealed as a critical factor for the discovery of new disease variants. Here, we present the Collaborative Spanish Variability Server (CSVS), which currently contains more than 2000 genomes and exomes of unrelated Spanish individuals. This database has been generated in a collaborative crowdsourcing effort collecting sequencing data produced by local genomic projects and for other purposes. Sequences have been grouped by ICD10 upper categories. A web interface allows querying the database removing one or more ICD10 categories. In this way, aggregated counts of allele frequencies of the pseudo-control Spanish population can be obtained for diseases belonging to the category removed. Interestingly, in addition to pseudo-control studies, some population studies can be made, as, for example, prevalence of pharmacogenomic variants, etc. In addition, this genomic data has been used to define the first Spanish Genome Reference Panel (SGRP1.0) for imputation. This is the first local repository of variability entirely produced by a crowdsourcing effort and constitutes an example for future initiatives to characterize local variability worldwide. CSVS is also part of the GA4GH Beacon network. CSVS can be accessed at: http://csvs.babelomics.org/.

A Predictive Model of Bilateral Sensorineural Hearing Loss in Meniere Disease Using Clinical Data.

OBJECTIVES: Meniere disease (MD) is defined by a clinical syndrome of recurrent attacks of spontaneous vertigo associated with tinnitus, aural fullness, and sensorineural hearing loss (SNHL). Most patients have unilateral SNHL, but some of them will develop contralateral SNHL during the course of the disease. Several studies have reported a frequency of 2 to 73% SNHL in the second ear, according to the duration of disease and the period of follow-up. We hypothesize that unilateral and bilateral MD are different conditions, the first would initially involve the apical turn of the cochlea, while bilateral MD would affect the entire length of the cochlea. The aim of the study is to search for clinical predictors of bilateral SNHL in MD to build a predictive model of bilateral involvement. DESIGN: A retrospective, longitudinal study including two cohorts with a total of 400 patients with definite MD was carried out. The inception cohort consisted of 150 patients with MD and the validation cohort included 250 cases. All of the cases were diagnosed of unilateral MD according to their hearing loss thresholds. The following variables were assessed as predictors of bilateral SNHL for the two cohorts: sex, age of onset, familiar history of MD, migraine and high-frequency hearing loss (HFHL, defined if hearing threshold >20 dB in two or more consecutive frequencies from 2 to 8 KHz). A descriptive analysis was carried out according to the presence of HFHL in the first audiogram for the main variables. By using multiple logistic regression, we built-up several predictive models for the inception cohort and validated it with the replication cohort and merged dataset. RESULTS: Twenty-three (19.3%) and 78 (41%) of patients with HFHL developed contralateral SNHL during the follow-up, in the inception and validation cohorts, respectively. In the inception cohort, the best predictive model included HFHL in the first audiogram (OR = 6.985, p = 0.063) and the absence of migraine (OR = 0.215, p = 0.144) as clinical predictors for bilateral SNHL [area under the curve (AUC) = 0.641, p = 0.002]. The model was validated in the second cohort (AUC = 0.621, p < 0.001). Finally, we merged both datasets to improve the precision of the model including HFHL in the first audiogram (OR = 3.168, p = 0.001), migraine (OR = 0.482, p = 0.036) and age of onset >35 years old (OR = 2.422, p = 0.006) as clinical predictors (AUC = 0.639, p < 0.001). CONCLUSIONS: A predictive model including the age of onset, HFHL in the first audiogram and migraine can help to assess the risk of bilateral SNHL in MD. This model may have significant implications for clinical management of patients with MD.

Enrichment of damaging missense variants in genes related with axonal guidance signalling in sporadic Meniere's disease.

INTRODUCTION: Meniere's disease (MD) is a rare inner ear disorder with a significant genetic contribution defined by a core phenotype: episodic vertigo, sensorineural hearing loss and tinnitus. It has been mostly described in sporadic cases, familial cases being around 10% of the observed individuals. It is associated with an accumulation of endolymph in the inner ear, but the molecular underpinnings remain largely unknown. The main molecular pathways showing higher differentially expressed genes in the supporting cells of the inner ear are related to cochlea-vestibular innervation, cell adhesion and leucocyte extravasation. In this study, our objective is to find a burden of rare variants in genes that interact with the main signalling pathways in supporting cells of the inner ear in patients with sporadic MD. METHODS: We designed a targeted-sequencing panel including genes related with the main molecular pathways in supporting cells and sequenced 860 Spanish patients with sporadic MD. Variants with minor allele frequencies <0.1 in the gene panel were compared with three independent reference datasets. Variants were classified as loss of function, missense and synonymous. Missense variants with a combined annotation-dependent depletion score of >20 were classified as damaging missense variants. RESULTS: We have observed a significant burden of damaging missense variants in few key genes, including the NTN4 gene, associated with axon guidance signalling pathways in patients with sporadic MD. We have also identified active subnetworks having an enrichment of rare variants in sporadic MD. CONCLUSION: The burden of missense variants in the NTN4 gene suggests that axonal guidance signalling could be a novel pathway involved in sporadic MD.

Current Understanding and Clinical Management of Meniere's Disease: A Systematic Review.

Meniere's disease (MD) is a set of uncommon disorders with core phenotype of tinnitus, episodic vertigo, and sensorineural hearing loss. MD shows a genetic predisposition and a family history is found in 10% cases, with an autosomal dominant inheritance pattern. It is a multifactorial condition whose onset and development are triggered by the combined effect of genetic and environmental factors. Histopathological studies have associated MD with the accumulation of endolymph in the cochlea and the vestibular organs. However, endolymphatic hydrops does not fully explain the persistence of tinnitus, hearing loss progression, or the frequency of vertigo attacks.There are several comorbidities associated with MD, such as migraine, anxiety, autoimmune, and autoinflammatory disorders, adding more complexity to the phenotype. This "extended phenotype" can make the diagnosis and clinical management more complex, but it could also lead to a better characterization, understanding, and treatment of MD patients.We have conducted a systematic review on MD to update current knowledge, focusing on its mechanisms, diagnosis, comorbidities, and practical management.