Possible association between thyroid autoimmunity and Menière's disease

Statistical Associations between Vestibular Pathologies and Hypothyroidism: A Retrospective Study

The association between vestibular pathologies and thyroid hormone disorders has been known for several decades. However, very little information is available on the types of vestibular symptoms that may be affected by altered thyroid hormone levels. The aim of this study was to provide patient data in order to identify statistical associations between vestibular pathologies and thyroid hormone disorders. A retrospective review of the records of 422 patients seen for physiotherapy treatment of vertigo was carried out. Statistical analysis of the data was performed using logistic regression, providing Chi2 and Odds Ratio statistics. Our results show that hypothyroidism statistically significantly increases the expression of certain symptoms, such as vestibular instability and gait disorders, in vestibular pathologies such as Menière's disease or central vertigo. By analyzing patient data, our study provides new evidence of dependence between altered thyroid status and the expression of vestibular pathologies.

Thyroid Axis and Vestibular Physiopathology: From Animal Model to Pathology

A recent work of our group has shown the significant effects of thyroxine treatment on the restoration of postural balance function in a rodent model of acute peripheral vestibulopathy. Based on these findings, we attempt to shed light in this review on the interaction between the hypothalamic-pituitary-thyroid axis and the vestibular system in normal and pathological situations. Pubmed database and relevant websites were searched from inception through to 4 February 2023. All studies relevant to each subsection of this review have been included. After describing the role of thyroid hormones in the development of the inner ear, we investigated the possible link between the thyroid axis and the vestibular system in normal and pathological conditions. The mechanisms and cellular sites of action of thyroid hormones on animal models of vestibulopathy are postulated and therapeutic options are proposed. In view of their pleiotropic action, thyroid hormones represent a target of choice to promote vestibular compensation at different levels. However, very few studies have investigated the relationship between thyroid hormones and the vestibular system. It seems then important to more extensively investigate the link between the endocrine system and the vestibule in order to better understand the vestibular physiopathology and to find new therapeutic leads.

Elevated G-CSF, IL8, and HGF in patients with definite Meniere's disease may indicate the role of NET formation in triggering autoimmunity and autoinflammation

The etiology and mechanism causing Meniere’s disease (MD) are not understood. The present study investigated the possible molecular mechanism of autoimmunity and autoinflammation associated with MD. Thirty-eight patients with definite MD and 39 normal volunteers were recruited, and 48 human cytokines/chemokines were quantified. In patients with MD pure tone audiograms, tympanograms and standard blood tests were performed. The mean hearing loss in the worse ear was 44.1 dB nHL. Compared to the referents, the concentrations of TNFα, IL1α, IL8, CTACK, MIP1α, MIP1β, G-CSF, and HGF in the sera of patients with MD were significantly elevated, while those of TRAIL and PDGFBB were significantly decreased. The area under the receiver operating characteristic curve (AUC) showed that G-CSF, MIP1α, and IL8 were above 0.8 and could be used to diagnose MD (p < 0.01), and the AUCs of CTACK and HGF were above 0.7 and acceptable to discriminate the MD group from the control group (p < 0.01). The revised AUCs (1 − AUC) of TRAIL and PDGFBB were above 0.7 and could also be used in the diagnosis of MD (p < 0.01). The linear regression showed significant correlations between MIP1α and GCSF, between IL2Rα and GCSF, between IL8 and HGF, between MIP1α and IL8, and between SCF and CTACK; there was a marginal linear association between IP10 and MIP1α. Linear regression also showed that there were significant age-related correlations of CTACK and MIG expression in the MD group (p < 0.01, ANOVA) but not in the control group. We hypothesize that G-CSF, IL8, and HGF, which are involved in the development of neutrophil extracellular traps (NETs) and through various mechanisms influence the functions of macrophages, lymphocytes, and dendritic cells, among others, are key players in the development of EH and MD and could be useful in elucidating the pathophysiological mechanisms leading to MD. Biomarkers identified in the present study may suggest that both autoimmune and autoinflammatory mechanisms are involved in MD. In the future, it will be valuable to develop a cost-effective method to detect G-CSF, IL8, HGF, CTACK, MIP1α, TRAIL, and PDGFBB in the serum of patient that have diagnostic relevance.

Prevalence of Ménière's Disease in Syrian Patients with hypothyroidism: Cross-sectional study

Background

Ménière's Disease, a long-term debilitating disorder has been increasingly found among patients with hypothyroidism. Our study aims to evaluate the prevalence of ménière's disease among hypothyroid patients and assess the interrelationship between patients' symptomology and ménière's disease.

Materials and methods

A cross-sectional study was performed at the endocrinology clinics at Damascus Hospital and Syrian Red Crescent Hospital, Damascus, Syria between September 2021 and January 2022. Patients with hypothyroidism were interviewed using a questionnaire. The questionnaire contained questions about socio-demographic information, hypothyroid history, diagnostic criteria of ménière's disease, chief complaint, medical history, and lab test results. Patients, who reported ménière's disease symptoms, were referred to the otorhinolaryngology clinic for confirmation or exclusion of ménière's disease. At the clinic, patients underwent an otoscopy and a pure tone audiometry, probable and definite ménière's disease was diagnosed accordingly.

Results

Of 217 hypothyroid patients included in the sample, 17 (7.8%) were diagnosed with definite ménière's disease and 31 (14.3%) were diagnosed with probable ménière's disease. Hypothyroid symptoms reported among patients diagnosed with definite ménière's disease compared to no diagnosis differed by feeling low (χ2 (1, 217) = 4.014, p = 0.045), and depressive appearance (χ2 (1, 217) = 8.887, p = 0.003). Patients diagnosed with definite ménière's disease, probable ménière's disease, and both definite and probable ménière's disease were more likely to report that their symptoms affected their lifestyle compared to those that reported no effect (χ2 (3, 217) = 62.565, p < 0.001), (χ2 (3, 217) = 31.380, p < 0.001), and (χ2 (3, 217) = 35.542, p < 0.001), respectively.

Conclusion

A high number of hypothyroid patients were diagnosed with MD. Clinicians should consider clinically screening for MD among hypothyroid patients presenting to clinics.

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This study shows a significant association between hypothyroidism and Ménière's disease.

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Rates of feeling low and depressive appearance increase in definite MD patients.

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Meniere's disease patients were predisposed to the disease's effect on their lifestyle.

Evaluation of a large cohort of adult patients with Ménière's disease: bedside and clinical history

Objective

The purpose of this study was to assess vestibular findings and clinical history in a large cohort of patients affected by Ménière’s disease.

Methods

We retrospectively analysed 511 adult patients fulfilling criteria for definite unilateral Ménière’s disease according to Barany Society. Thorough clinical history, audiometric exam, central nervous system MRI, quantification of serum autoantibodies and complete vestibular function test were performed.

Results

Mean age at clinical record was 55.4 years, while age at onset of the first vertigo attack was 47.4 ± 14.3 years. Ménière’s disease overlapped with migraine in 43.4% of patients. In 31.7% of cases, positivity was found for at least one autoantibody. Forty-nine patients (9.6%) had family history for Ménière’s disease. Bedside examination resulted in 14.7% positivity for video head impulse test, 58.9% for skull vibration-induced nystagmus, 38.7% for the positional test and 23.1% for the post head shaking test. Complete negative examination was reported in 115 cases.

Conclusions

Ménière’s disease was seen to present a characteristic phenotypic pattern in our cohort, confirming the crucial role of thorough anamnesis and bedside examination in diagnosis.

Thyroid Dysfunction in Ménière's Disease: A Comprehensive Review

INTRODUCTION

The precise etiology of Ménière's disease (MD) remains unknown; however, given the association of MD with serum antibodies and human leukocyte antigen (HLA) complex, several studies have proposed a relationship between MD and thyroid disorders. Similarly, multiple hypotheses exist regarding the metabolic disturbances of fluctuating thyroid hormone as a potential contributing agent in the development of MD.

METHODS

A total of 171 abstracts were identified and screened by 2 independent reviewers. Based on inclusion and exclusion criteria, 8 studies were selected for final analysis. Due to heterogeneity of clinical data, meta-analysis was not feasible.

RESULTS

The prevalence of autoimmune thyroid disease and hypothyroidism in MD varied significantly from 1 to 38%. Notable bias was introduced given the lack of standardization of diagnostic criteria across studies. Articles that described autoimmune thyroid-specific antibodies and HLA types also presented inconclusive results. Multiple studies noted a potential etiologic role of hypothyroidism in MD, which was often confounded by thyroxine supplementation.

CONCLUSIONS

Despite a potential correlation in the medical literature between thyroid disorders and MD, there is currently no definitive causal relationship. Although most of the present medical literature focuses on autoimmunity, dysregulated thyroid hormone levels may also be implicated in the association of MD with thyroid disorders.

Association between Ménière's disease and thyroid diseases: a nested case-control study

The association of thyroid disease and Ménière’s disease would suggest that both are autoimmune diseases. This study aimed to investigate the relation of goiter, hypothyroidism, thyroiditis, hyperthyroidism, and autoimmune thyroiditis with Ménière’s disease. The Korean National Health Insurance Service-Health Screening Cohort data from 2002 through 2015 were used. The 8183 adult patients with Ménière’s disease were 1:4 matched with the 32,732 individuals of the control group for age, sex, income, and region of residence. The previous histories of thyroid disorders including goiter, hypothyroidism, thyroiditis, and hyperthyroidism were investigated using conditional logistic regression analyses. Subgroup analyses were conducted, including for age and sex. Smoking, alcohol consumption, obesity, Charlson Comorbidity Index, histories of benign paroxysmal vertigo, vestibular neuronitis, other peripheral vertigo, thyroid cancer, and levothyroxine medication were adjusted in the models. The histories of goiter (5.7% vs. 4.2%), hypothyroidism (4.7% vs. 3.6%), thyroiditis (2.1% vs. 1.6%), hyperthyroidism (3.6% vs. 2.5%), and autoimmune thyroiditis (0.99% vs. 0.67%) were higher in the Meniere’s disease group than in the control group (all P < 0.05). The histories of goiter, hypothyroidism, and hyperthyroidism were associated with Ménière’s disease (adjusted odds ratio (OR) = 1.19 [95% confidence interval (CI) = 1.04–1.36] for goiter, 1.21 [95% CI 1.02–1.44] for hypothyroidism, and 1.27 [95% CI 1.09–1.49] for hyperthyroidism, each of P < 0.05). In subgroup analyses, hypothyroidism was associated with Ménière’s disease in < 65-year-old women. Hyperthyroidism was related with Ménière’s disease in women overall. Thyroid diseases of goiter, hypothyroidism, and hyperthyroidism were associated with Ménière’s disease.

Climacteric symptoms are related to thyroid status in euthyroid menopausal women

BACKGROUND

Climacteric symptoms are a variety of disturbing complaints occurring during menopausal transition, many of which may be influenced by hormonal abnormalities other than related to sex steroids.

AIM OF THE STUDY

In this study, we investigated the association between the intensity of climacteric symptoms measured with the Kupperman index and a thyroid status.

MATERIAL AND METHODS

We evaluated by measuring serum thyrotropin (TSH), and free thyroxine (fT4) 202 euthyroid women admitted to the Department of Gynecological Endocrinology, Poznan University of Medical Sciences because of climacteric symptoms. Patients were both in perimenopause (n = 74) and postmenopause (n = 128), with no history of thyroid disorders.

RESULTS

Results presented as the mean value and standard deviation were as follows: age 54.2 ± 4.9 years, BMI 26.8 ± 4.6 kg/m², Kupperman index 26 ± 13.1 points, TSH 2.4 ± 2.6 mU/l, fT4 1.2 ± 0.37 ng/dl. We observed a negative correlation between fT4 and the time since the last menses (R = - 0.38; p = 0.02) as well as between serum TSH concentration and sweating (R = - 0.18; p = 0.03), general weakness (R = - 0.17; p = 0.03), and palpitation (R = - 0.18; p = 0.02) and a positive correlation between fT4 and nervousness (R = 0.34; p = 0.007) and palpitations (R = 0.25; p = 0.04). In the perimenopausal subgroup, there was a positive correlation between fT4 and general weakness (R = 0.42; p = 0.03), palpitations (R = 0.50; p = 0.009), and paresthesia (R = 0.46; p = 0.01). In the postmenopausal subgroup, there was a negative correlation between TSH and sweating (R = - 0.21; p = 0.03).

CONCLUSIONS

Menopausal symptoms are related to thyroid status in euthyroid menopausal women.

Circulating Immune Complexes and Heat Shock Protein 70 in the Sera of Patients with Sudden Sensorineural Hearing Loss

OBJECTIVES

The aim of this paper is to analyze and assess the usefulness of heat shock protein 70 (Hsp70) and circulating immune complexes (CIC) in patients with sudden sensorineural hearing loss (SSHL) in a tertiary care hospital in a research university (2014-2017).

MATERIALS AND METHODS

Patients were interviewed about the history of diseases; underwent an ear, nose, and throat (ENT) examination; a hearing test; and were analyzed for the presence of CIC and Hsp70 protein. A simple dot blot method was designed for the purpose of identification of Hsp70 bound to CIC and free Hsp70.

RESULTS

In 59.4% of patients with idiopathic SSHL, elevated levels of immune complexes were observed. Compared with healthy subjects, a significant difference was noted (p=0.00016). Positive reactions to the presence of free Hsp70 protein were noted in the sera of 48.4% of patients. In the control group, free Hsp70 was observed in 8% of patients (p=0.0000034). Hsp70 bound to CIC was detected in the sera of 62.5% of patients; and in healthy cases, in 12% (p<0.0001).

CONCLUSION

In the sera of persons with SSHL, there are elevated levels of CIC and Hsp70. After the application of the innovative method for determining the occurrence of Hsp70 bound to CIC, it was stated that its presence is greater than that of free Hsp70, commonly detected by means of the Western-blot method. The dot blot method applied in the present study increases the Hsp70 identification and by the same token increases the probability of detection of autoimmunological background of SSHL.

Autoimmune vertigo: an update on vestibular disorders associated with autoimmune mechanisms

The role of the immune system in mediating cochleovestibular pathologies has received increasing attention in recent years. Autoimmune vertigo may be an invalidating condition and may worsen the quality of life of affected patients, especially in the cases of delayed diagnosis. Since the etiopathogenesis is still not clear, also the treatment is not yet completely delineated. According to the clinical presentation, autoimmune vertigo can present as an isolated disorder or in association with systemic autoimmune diseases. The main feature in autoimmune vertigo is the presence of an abnormal immune response, in either absence or presence of systemic autoimmune disease, directed against delicate components of the inner ear. This may determine a functional or anatomical alteration, with an inflammatory reaction often devastating for hearing and balance. Being the exact pathogenesis unknown, the diagnosis of autoimmune vertigo is based either on clinical criteria or on a positive response to steroids. The earlier the diagnosis is made, the sooner the therapy can be installed, giving a chance to the recovery of inner ear damages. Corticosteroids represent the most effective and universally accepted treatment, even if other immunomodulatory drugs are now having a more extensive use. HIGHLIGHTS: Vertigo is relatively frequent in autoimmune diseases; however, it is often misdiagnosed or attributed to central nervous system alterations rather to specific inner ear involvement. Vertigo and other audiovestibular symptoms may be the first manifestation of an autoimmune disease and if correctly addressed could significantly contribute to early diagnosis of the underlying autoimmune disease. Early diagnosis of immune-related vertigo can lead to prompt initiation of targeted therapy with elevate chances of preventing irreversible damages to the inner ear. The presence of alternating phases of well-being and disabling symptoms in patients with vertigo should always been considered, as they could suggest an underlying autoimmune condition.

Pathophysiologic Findings in the Human Endolymphatic Sac in Endolymphatic Hydrops: Functional and Molecular Evidence

BACKGROUND

The endolymphatic sac (ES) is a cystic structure situated on the posterior fossa dura and is connected to the luminal space of the vestibular organ through the endolymphatic duct, which branches into the utricular and saccular ducts. Unlike the cochlea and vestibule, the ES does not contain sensory epithelium in its luminal space, and a single layer of epithelial cells line the luminal surface area. The ES in the inner ear is thought to play a role in the regulation of inner ear homeostasis, fluid volume, and immune reaction. If these functions of the ES are disrupted, dysfunction of the inner ear may develop. The most well-known pathology arising from dysfunction of the ES is endolymphatic hydrops, characterized by an enlarged endolymphatic space due to the accumulation of excessive endolymphatic fluid. Although, molecular identities and functional evidence for the roles were identified in animal studies, basic studies of the human ES are relatively uncommon compared with those using animal tissues, because of limited opportunity to harvest the human ES.

METHODS

In this study, molecular and functional evidence for the role of the human ES in the development of endolymphatic hydrops are reviewed.

RESULTS AND CONCLUSIONS

Although evidence is insufficient, studies using the human ES have mostly produced findings similar to those of animal studies. This review may provide a basis for planning further studies to investigate the pathophysiology of disorders with the finding of endolymphatic hydrops.

Hypothyroidism is an independent risk factor for Menière's disease: A population-based cohort study

The relationship of hypothyroidism and Menière's disease (MD) has been discussed before, yet not well documented. Our study aims to investigate the correlation of both diseases.This is a retrospective cohort study based on data from the LHID2000 (Longitudinal Health Insurance Database 2000), a subset of the Taiwan National Research Health Insurance Database that contains claims data for the 2000 to 2011 period. A total of 27,050 patients were included in this study, 5410 of whom had received a hypothyroidism diagnosis. The prevalence of MD was high in patients with hypothyroidism (95% confidence interval [CI]: 1.14-1.51), especially in those older than 50 years old (P < .001). Although comorbidities such as hypertension or cirrhosis are significant risk factors for Menière's disease (P < .001, P < .05), the incidence rate of Menière's disease in patients with hypothyroidism differs significantly between groups without these comorbidities (95% CI: 1.14-1.95). Regarding the timing for the occurrence of Menière's disease in patients with hypothyroidism, there was a significant time interval of <5 years (P < .05). The risk of MD decreased after treatment with thyroxine and did not differ from that of the nonhypothyroidism cohort (adjusted HR [aHR] = 0.85, 95% CI: 0.66-1.11).The study demonstrates a significant association between hypothyroidism and Menière's disease, especially in elderly female patients. Physicians should consider verifying the thyroid function when encountering these patients.

Serum sickness disease in a patient with alopecia areata and Meniere' disease after PRP procedure

BACKGROUND

Platelet rich plasma procedure (PRP) is considered to be one of the safest aesthetic procedures. Adverse reactions after PRP administration are extreme rare.

PURPOSE

We present the patient with serum sickness disease (SSD) after PRP procedure.

OBJECTIVE AND METHODS

41 years old female suffers from alopecia areata for 5 years with frequent relapses and she has been suffering from Menier's disease recurrent symptoms for 6 years. The patient developed SSD after third PRP rejuvenating procedure and she has also noticed new alopecia areata lesions, but without Menier's disease symptoms. After SSD, 4 months later, she developed severe symptoms of Menier's disease with an episode of sudden sensorineural hearing loss. It alleviated only after intravenous administration of methylprednisolone. In our opinion, significant contraindication of PRP procedure is an autoimmune disease in the active phase.

Gadolinium-enhanced MRI reveals dynamic development of endolymphatic hydrops in Ménière's disease

INTRODUCTION

Meniere's disease is associated with impaired hearing, tinnitus, vertigo, and aural fullness. Many anatomical studies have suggested idiopathic endolymphatic hydrops as the pathological basis of Meniere's disease, which now can be visualized by using gadolinium -enhanced magnetic resonance imaging of the inner ear.

OBJECTIVE

To investigate the development of endolymphatic hydrops in Meniere's disease by monitoring the vestibules and cochleae of affected patients.

METHODS

Inner ears of 178 patients with definite unilateral Meniere's disease diagnosis were visualized by 3-dimensional fluid-attenuated inversion recovery and three-dimensional real inversion recovery magnetic resonance imaging following bilateral gadolinium intratympanic injection. The scans were used to evaluate the presence and degree of endolymphatic hydrops in the vestibules and cochlear structures, including the cochlear apical turn, the cochlear middle turn, and the cochlear basal turn. The correlation of endolymphatic hydrops occurrence between the various parts of the inner ear was determined.

RESULTS

Symptomatic endolymphatic hydrops was detected on the affected side in all patients, whereas asymptomatic endolymphatic hydrops was detected on the unaffected contra-lateral side in 32 patients (18.0%). On the affected side, the cochlear apical turn and the cochlear middle turn demonstrated significantly higher rates of endolymphatic hydrops than the cochlear basal turn and the vestibule. The severity of endolymphatic hydrops gradually decreased from the cochlear apical turn to the cochlear basal turn. On the contra lateral side, the incidence and degree of the detected asymptomatic endolymphatic hydrops were significantly greater in the cochleae than in the vestibules (p<0.05), with no significant difference detected between the cochlear turns.

CONCLUSION

Progression of endolymphatic hydrops appears to be directional, initiated in the cochlea. The order of endolymphatic hydrops severity gradually decreases from the cochlear apical turn to the cochlear basal turn and then to the vestibule. Endolymphatic hydrops in the vestibule is associated with symptomatic Meniere's disease.

Update on Vertigo in Autoimmune Disorders, from Diagnosis to Treatment

The prevalence of autoimmune diseases has been increasing over the last 20 years. The clinical presentation of this large and heterogeneous group of disorders depends on whether the involvement is organ-specific or non-organ-specific. Dizziness, vertigo, and disequilibrium are common symptoms reported by patients with vestibulocochlear involvement. The association of vertigo and autoimmune diseases has been largely documented, suggesting that autoimmune disorders could be overrepresented in patients with vertigo in comparison to the general population. The aim of this review is to present the recent literature findings in the field of autoimmune-mediated diseases with cochleovestibular involvement, focusing on the clinical presentation, diagnosis, and treatment of immune-mediated inner ear diseases including autoimmune inner ear disease (AIED), Meniere's disease, and bilateral vestibulopathy, as well as of systemic autoimmune diseases with audiovestibular disorders, namely, Behçet's disease, Cogan's syndrome, sarcoidosis, autoimmune thyroid disease, Vogt-Koyanagi-Harada syndrome, relapsing polychondritis, systemic lupus erythematosus, antiphospholipid syndrome, IgG4-related disease, and ANCA-associated vasculitides.

The aetiopathologies of Ménière's disease: a contemporary review

Ménière's disease, a condition first described in the 1800's, has been an advancing area of clinical interest and scientific research in recent decades. Guidelines published by the American Academy of Otolaryngology - Head and Neck Surgery remained nearly static for almost 20 years, although we have certainly expanded our knowledge of the aetiology of the disease since that time. This review of the literature highlights the breadth and detail of the current theories in understanding the pathophysiology of this enigmatic disease. Histopathological specimens providing evidence of many of the aetiologies are presented as well. We aim to provide a centralised and updated resource regarding current and emerging theories for Ménière's disease.

RNA-sequencing study of peripheral blood mononuclear cells in sporadic Ménière's disease patients: possible contribution of immunologic dysfunction to the development of this disorder

To date, the pathogenesis of Ménière's disease (MD) remains unclear. This study aims to investigate the possible relationship between potential immune system-related genes and sporadic MD. The whole RNA-sequencing (RNA-seq) technology was used to analyse the transcriptome of peripheral blood mononuclear cells of three MD patients and three control individuals. Of 366 differentially expressed genes (DEGs), 154 genes were up-regulated and 212 genes were down-regulated (|log₂ fold change| > 1 and P < 0·05). Gene ontology (GO) enrichment analysis illustrated that immune relevant factors played a key role in the pathogenesis of MD. Of 366 DEGs, we focused upon analysing the possible immune-related genes, among which the significantly up-regulated genes [glutathione S-transferase mu 1 (GSTM1), transmembrane protein 176 (TMEM176)B, TMEM176A] and down-regulated genes [solute carrier family 4 member (SLC4A)10 and SLC4A1] especially drew our attention. The mRNA expression levels of GSTM1, TMEM176B, TMEM176A, SLC4A1 and SLC4A10 were analysed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The serum concentration of GSTM1, TMEM176B and SLC4A10 proteins were measured by enzyme-linked immunosorbent assay (ELISA). Considering the results of qRT-PCR and ELISA, it was noteworthy that GSTM1 exhibited the highest fold change between two groups, which was consistent with the deep sequencing results by RNA-seq. In conclusion, our study first offers a new perspective in MD development on the basis of RNA expression patterns, suggesting that immune factors might be involved in the MD pathogenesis. Remarkably, GSTM1 might be a possible candidate gene for the diagnostic biomarker of MD and provides the basis for further biological and functional investigations.

Clinical Subgroups in Bilateral Meniere Disease

Meniere disease (MD) is a heterogeneous clinical condition characterized by sensorineural hearing loss, episodic vestibular symptoms, and tinnitus associated with several comorbidities, such as migraine or autoimmune disorders (AD). The frequency of bilateral involvement may range from 5 to 50%, and it depends on the duration of the disease. We have performed a two-step cluster analysis in 398 patients with bilateral MD (BMD) to identify the best predictors to define clinical subgroups with a potential different etiology to improve the phenotyping of BMD and to develop new treatments. We have defined five clinical variants in BMD. Group 1 is the most frequently found, includes 46% of patients, and is defined by metachronic hearing loss without migraine and without AD. Group 2 is found in 17% of patients, and it is defined by synchronic hearing loss without migraine or AD. Group 3, with 13% of patients, is characterized by familial MD, while group 4, that includes 12% of patients, is associated by the presence of migraine in all cases. Group 5 is found in 11% of patients and is defined by AD. This approach can be helpful in selecting patients for genetic and clinical research. However, further studies will be required to improve the phenotyping in these clinical variants for a better understanding of the diverse etiological factors contributing to BMD.

Do antithyroid antibodies affect hearing outcomes in patients with pediatric euthyroid Hashimoto's thyroiditis?

OBJECTIVES

Hashimoto's thyroiditis (HT) is the most common autoimmune thyroid disease in children. HT is a multifaceted disease with a variable clinicopathological presentation, including hearing impairment. It is known that hearing function is negatively affected in patients with thyroid disorders. The literature includes a very limited number of studies on hearing function in euthyroid pediatric patients with HT. The aim of this study was to determine the relationship between cochlear function and HT, independent of thyroid function.

MATERIALS AND METHODS

The study included 48 children and adolescents (42 females and 6 males) aged 9-18 years that were diagnosed as HT, and 30 gender- and age-matched healthy controls. Hearing was assessed via otoscopy, tympanometry, pure-tone audiometry, and measurement of distortion product otoacoustic emissions.

RESULTS

There weren't any significant differences in pure tone thresholds between the 2 groups based on pure-tone audiometry, except in the right ear at 6kHz and 8kHz. Distortion product otoacoustic emissions signal to noise ratios were significantly lower in the HT group than in the control group at 4 different frequencies (6kHz [left ear], 8kHz [left ear], 1.5kHz [right ear], and 6kHz [right ear]) (P<0.05). The signal to noise ratios at all frequencies were <6dB in 3% of left ears and 2.5% of right ears in the control group, versus 12.5% of left ears and 9.6% of right ears in the HT group. Distortion product amplitudes were significantly lower in the HT group than in the control group for both left and right ears at 1kHz, 1.5kHz, 3kHz, and 8kHz, and at 2kHz for left ears only (P<0.05).

CONCLUSIONS

The present findings show that cochlear function was lower in the HT group than in the control group. Accordingly, we think that hearing in patients with HT should be monitored periodically, even if their hearing thresholds are within normal limits. Thyroid autoimmunity appears to play an important role in a decrease in cochlear activity in pediatric HT patients.

Evaluation of hearing functions in patients with euthyroid Hashimoto's thyroiditis

Sensorineural hearing loss has been reported in various autoimmune diseases. The relationship between Hashimoto's thyroiditis (HT) and the auditory system has not been previously evaluated. In this study, we investigated the effect of euthyroid HT on the hearing ability of adult patients. The study included 30 patients with newly diagnosed euthyroid HT and 30 age- and gender-matched healthy controls. All subjects had a normal otoscopic examination and tympanometry, and they were negative for rheumatoid factor, antinuclear, anti-smooth muscle, antimitochondrial, antineutrophilcytoplasmic, and antigliadin antibodies. Pure tone audiometry exams at 250, 500, 1000, 2000, 4000, 6000, and 8000 Hertz (Hz) were performed in both groups. Thyroid peroxidase antibody and thyroglobulin antibody (anti-Tg) levels were higher in HT group while TSH, free T4, free T3, plasma electrolytes, glucose, lipid profile, vitamin B12, and blood pressure measurements were similar between the two groups. Higher audiometric thresholds and a higher prevalence of hearing loss at 250, 500, and 6000 Hz were detected in the HT patients than in the healthy controls (P < 0.05). Hearing levels at 250 and 500 Hz correlated positively with anti-Tg levels (ρ = 0.650, P = 0.002; ρ = 0.719, P < 0.001, respectively), and this association remained significant in linear regression analysis. Anti-Tg-positive HT patients had higher hearing thresholds at 250 and 500 Hz than anti-Tg-negative HT patients. Hearing thresholds were similar between anti-Tg-negative HT patients and the control subjects. This study demonstrated that hearing functions are impaired in HT patients. Thyroid autoimmunity seems to have an important impact on a decreased hearing ability, particularly at lower frequencies, in this population of patients.

Auto-inflammatory challenge of the endolymphatic sac--Cochlear damage measured by distortion product oto-acoustic emissions

CONCLUSION

Twenty-five rats were challenged by an immunologic attack of the endolymphatic sac. After 6 months, distortion product oto-acoustic emissions (DPOAE) revealed a dysfunction of the outer hair cells and immunological active cells were observed in the endolymphatic sac. This information could contribute to the understanding of Ménière's disease.

OBJECTIVES

This study investigated if an autoimmune challenge of the endolymphatic sac could affect DPOAE output measurements in rats. Also, a potential autoimmune cell infiltration of the endolymphatic sac was investigated.

METHODS

Eighteen Lewis rats were immunized with a crude endolymphatic sac extract in complete Freund's adjuvant. Seven control animals were injected with Freund's adjuvant in saline. Cochlear damage was estimated by DPOAE dynamics 3 weeks and 6 months after the immunization. Infiltrative cells in the endolymphatic sac were investigated with transmission electron microscopy.

RESULTS

The hearing assessment 6 months after immunization revealed a reduction of the DPOAE, on the full range of frequencies (2-63 kHz) in an average of the mean, of 2 dB ± 1.1 in the immunized group compared to the controls (p < 0.05). The same test showed a 2.5 dB decrease from 2 to 5 kHz (p < 0.01). Immunological active cells were observed in the endolymphatic sac in most of the immunized rats.

The role of thyroid and parathyroid metabolism disorders in the etiology of sudden onset dizziness

Background

The aim of this study was to evaluate thyroid and parathyroid functions as a cause of sudden onset dizziness (SOD) in patients who were admitted to the Emergency Department (ED).

Material/Methods

This study was conducted prospectively in 100 patients with sudden onset dizziness (SOD) admitted to the ED. Neurologic, ear-nose-throat, detailed neck examinations, serum calcium levels, thyroid function tests (TFT), and parathormone and thyroid ultrasounds were performed on all patients in our study.

Results

Thirty-seven (37%) females and 63 (63%) males were included in this study. Four patients (4%) had elevated serum TSH levels, 6 (6%) had decreased serum fT3 levels, 10 (10%) had decreased serum fT4 levels, 2 (2%) had elevated serum fT4 levels, and 2 (2%) had elevated serum parathormone levels. In 4 (4%) patients, the serum calcium levels were lower than normal, and 2 (50%) of these patients had symptomatic hypocalcemia. Thyroid ultrasound examinations showed multinodular goiter in 28 (28%) patients, 2 (2%) patients had thyroiditis, 12 (12%) had an isolated unilateral nodule, and 58 (58%) had normal thyroid tissues.

Conclusions

We suggest that detailed neck examination, TFT, and thyroid ultrasound examination should be considered in the diagnostic algorithms of SOD to provide rapid diagnosis and proper treatment for a patient in the ED.

Autoimmunity as a candidate for the etiopathogenesis of Meniere's disease: detection of autoimmune reactions and diagnostic biomarker candidate

Meniere's disease is an inner ear disorder that can manifest as fluctuating vertigo, sensorineural hearing loss, tinnitus, and aural fullness. However, the pathologic mechanism of Meniere's disease is still unclear. In this study, we evaluated autoimmunity as a potential cause of Meniere's disease. In addition we tried to find useful biomarker candidates for diagnosis. We investigated the protein composition of human inner ear fluid using liquid column mass spectrometry, the autoimmune reaction between circulating autoantibodies in patient serum and multiple antigens using the Protoarray system, the immune reaction between patient serum and mouse inner ear tissues using western blot analysis. Nine proteins, including immunoglobulin and its variants and interferon regulatory factor 7, were found only in the inner ear fluid of patients with Meniere's disease. Enhanced immune reactions with 18 candidate antigens were detected in patients with Meniere's disease in Protoarray analysis; levels of 8 of these antigens were more than 10-fold higher in patients than in controls. Antigen-antibody reactions between mouse inner ear proteins with molecular weights of 23–48 kDa and 63–75 kDa and patient sera were detected in 8 patients. These findings suggest that autoimmunity could be one of the pathologic mechanisms behind Meniere's disease. Multiple autoantibodies and antigens may be involved in the autoimmune reaction. Specific antigens that caused immune reactions with patient's serum in Protoarray analysis can be candidates for the diagnostic biomarkers of Meniere's disease.

Vestibular disorders in euthyroid patients with Hashimoto's thyroiditis: role of thyroid autoimmunity

INTRODUCTION

A relationship between vestibular disorders and thyroid autoimmunity independently from thyroid function has been postulated.

AIM

To shed more light on the actual relationship between vestibular lesions and Hashimoto's thyroiditis (HT) regardless of thyroid function.

METHODS

Forty-seven patients with HT (89·4% F; aged 48·3 ± 12·7 years), 21 with multinodular goitre (MNG; 57·1% F; 54·1 ± 9·8 years) and 30 healthy volunteers (56·7% F; 50·7 ± 13·9 years) were enrolled. Inclusion criteria were the presence of normal thyroid function tests and no clinical history of vestibular dysfunction. Each subject was submitted to complete vestibular evaluation [Caloric Test, Vestibular evoked myogenic potentials (VEMPs), Head Shaking Test (HST)].

RESULTS

52·2% of HT patients showed an alteration of VEMPs and 44·7% of caloric test (P < 0·0001 for both). None of the MNG patients showed any vestibular alteration, while one healthy control showed an altered caloric test. A correlation was found between vestibular alterations of HT patients and the degree of serum TPOAb level, not affected by age and serum TSH value. By logistic regression analysis, the absence of thyroid autoimmunity significantly reduced the risk of vestibular alterations: HR 0.19 (95%CI: 0·003-0.25, P = 0·0004) for caloric test; HR 0·07 (95%CI: 0·02-0·425, P < 0·0001) for VEMPs; and HR 0·22 (95%CI: 0·06-0·7, P = 0·01) for HST.

CONCLUSION

In euthyroid HT patients, a significant relationship between subclinical vestibular damage and the degree of TPOAb titre was documented. This finding suggests that circulating antithyroid autoantibodies may represent a risk factor for developing vestibular dysfunction. An accurate vestibular evaluation of HT patients with or without symptoms is therefore warranted.

Allelic variants in TLR10 gene may influence bilateral affectation and clinical course of Meniere's disease

Toll-like receptors trigger the innate immune response by activating various cell types such us macrophages and lymphocytes. We genotyped SNV of TLR3, TRL7, TLR8 and TLR10 in 863 Spanish and 150 Italian patients with Meniere's disease (MD) and 1,013 controls by using Taqman assays. Real-Time qPCR was used to measure the expression level of TLR10 in peripheral blood leukocytes. The overall dataset showed that the C allele and the CC genotype of rs11096955 in TLR10 gene were more commonly observed in controls than patients (corrected p = 1 × 10(-3), OR = 0.68 [95 % confidence interval, 0.54-0.84] for CC genotype; corrected p = 1.5 × 10(-5), OR = 0.75 [0.66-0.85] for allele C). Moreover, the CC genotype was more frequent in patients with uni- (19 %) than bilateral sensorineural hearing loss (SNHL) (13 %). Logistic regression demonstrated that the time since the onset of MD, Tumarkin crises, hearing stage and rs11096955 were independent factors influencing the risk of bilateral SNHL. In addition, rs11096955 influenced hearing loss progression in patients with bilateral MD. No change in expression of TLR10 was observed according to CC, CA or AA genotypes. Our data suggest that allelic variants of TLR10 gene may influence the susceptibility and time-course of hearing loss of MD in the European population.

Experimental hyperactivity of the endolymphatic sac

Injury to the endolymphatic sac may play an important role in the pathogenesis of Ménière's disease, an inner ear disorder characterized by hearing loss, tinnitus and attacks of vertigo. Isoimmunization of 16 inbred Lewis rats with a crude endolymphatic sac extract and complete Freund's adjuvant induced hyperactivity of the endolymphatic sac. One group of rats was immunized by a single dose whereas a second group was immunized twice. Control animals were injected with Freund's adjuvant in saline only. Serum was collected from all rats by the end of the study and harvested autoantibodies were tested by immunohistochemistry. The endolymphatic sacs were investigated by transmission electron microscopy. Endolymphatic sac stimulation was observed in all immunized rats. Based on detailed ultrastructural observations, the degree of reactivity seemed proportional to the number of injections and the extent of immunization. Moreover, the ribosome-rich cells seemed hyperactive with an extravagant content of intracellular components: numerous rough endoplasmic reticulum and free ribosomes, morphological signs of extensive endo- and exocytosis, vesicles of material with a density similar to the homogeneous substance of which many were observed to fuse with primary lysozymes. Basolateral foldings were numerous and in the subepithelial capillaries formation of multiple and apposing fenestrations were observed. No endolymphatic sac stimulation was observed in the control animals. Specific ribosome-rich cell alterations identical to those present in the endolymphatic sac of Ménière's disease were observed 21 days after the first immunization. The observations suggest that either an autoantigen or a trophic factor, capable of inducing a hyperactivity of the ribosome-rich cells and an imbalance of the homogeneous substance metabolism, exists in the endolymphatic sac of the rat.

Polymorphisms of CD16A and CD32 Fcγ receptors and circulating immune complexes in Ménière's disease: a case-control study

BACKGROUND

Autoimmune diseases with elevated circulating autoantibodies drive tissue damage and the onset of disease. The Fcγ receptors bind IgG subtypes modulating the clearance of circulating immune complexes (CIC). The inner ear damage in Ménière's disease (MD) could be mediated by an immune response driven by CIC. We examined single-nucleotide polymorphism (SNPs) in the CD16A and CD32 genes in patients with MD which may determine a Fcγ receptor with lower binding to CIC.

METHODS

The functional CD16A (FcγRIIIa*559A > C, rs396991) and CD32A (FcγRIIa*519A > G, rs1801274) SNPs were analyzed using PCR-based TaqMan Genotyping Assay in two cohorts of 156 mediterranean and 112 Galicia patients in a case-control study. Data were analyzed by χ2 with Fisher's exact test and Cochran-Armitage trend test (CATT). CIC were measured by ELISA for C1q-binding CIC.

RESULTS

Elevated CIC were found in 7% of patients with MD during the intercrisis period. No differences were found in the allelic frequency for rs396991 or rs1801274 in controls subjects when they were compared with patients with MD from the same geographic area. However, the frequency of AA and AC genotypes of CD16A (rs396991) differed among mediterranean and Galicia controls (Fisher's test, corrected p = 6.9 × 10-4 for AA; corrected p = 0.02 for AC). Although genotype AC of the CD16A receptor was significantly more frequent in mediterranean controls than in patients, [Fisher's test corrected p = 0.02; OR = 0.63 (0.44-0.91)], a genetic additive effect for the allele C was not observed (CATT, p = 0.23). Moreover, no differences were found in genotype frequencies for rs396991 between patients with MD and controls from Galicia (CATT, p = 0.14). The allelic frequency of CD32 (rs1801274) was not different between patients and controls either in mediterranean (p = 0.51) or Galicia population (p = 0.11).

CONCLUSIONS

Elevated CIC are not found in most of patients with MD. Functional polymorphisms of CD16A and CD32 genes are not associated with onset of MD.