Autoimmune (AI) deafness Chanchai Jariengprasert Ramathibodi hospital 6th March, 2019 Autoimmune (AI) deafness

• Percentage of AI disorders in western countries ~8% of total pop • Increase in prevalence /incidence over last 20 years • Considered for a long time, inner ear (IE) – immune-privileged site, spared from organ-specific AI and rarely involved in systemic AI diseases [thank to blood-labyrinthine barrier – BLB] • EBM: cochlear-vestibular system might be affected by AI diseases • Dx of AI vestibular disorders probably overlooked due to absence of reliable test identify specific IE Ag Concept of immunity in idiopathic hypoacusia

• Introduced first by Joannovic [1920s] and Masugi and Tomizuka [1930s] • Lehnhardt hypothesize sudden or rapidly progressive SNHL result of AI process against IE, [1958], theorized “anticancer antibodies” as a cause of progressive bilateral hypacusia in 13 patients • In analogy to sympathetic ophthalmopathy, Kikuchi [1959] hypothesized “sympathetic otitis”, SNHL following surgery in contralateral ear, AI origin • Beickert, animal model, immunizing guinea pigs against IE tissues, subsequent appearance of cochlear damage, not hearing loss [1961] • McCabe [1979] success of steroid and cytotoxic tx in cohort of bilateral progressive SNHL, suggesting AI pathogenesis, definition: “AIED – a progressively bilateral SNHL, responds to immunosuppressives” BLB BLB

• IE always been considered a privileged immunological site: • Absence of lymphatic drainage • Presence of an effective blood-labyrinthine barrier (BLB) • BLB in stria vascularis: highly specialized network, controls exchanges b/w blood and interstitial space in cochlea • Maintaining ionic gradient and endocochlear potential for active processes of mechanical-electrical transduction of HCs • Endothelial cells connected by tight junctions, together with BM form a barrier to passage of many substances • Barrier also formed by pericitis and perivascular melanocytes (activated during exposure to noise) • Local immunity regulated by endolymphatic sac (ES), main Ag-processing site • Destruction of ES causes a reduction of immune response of IE Stria vascularis Autoimmune (AI) deafness

• Several studies showed inflammatory cells in IE, presence of resident cochlear macrophages in animal models and recruitment of inflammatory macrophages to cochlea • In 2016, O’Malley et al. identified cells with staining characteristics and morphology consistent with macrophages/microglia in human cochlea • Presence of these cells in AI diseases suggests an important role in IE pathology due to increased level of proinflammatory cytokines and reactive oxygen species (ROS) induced by microglia Autoimmune (AI) deafness

• Hughes et al. [1984] completed definition of McCabe and introduced distinction AI vestibular disorders classified into 2 groups: 1. (Primary) Immune-mediated IE disorders 2. (Secondary) Audio-vestibular (AV) pathology associated with systemic AI 1. Immune-Mediated IE Diseases

1.1. Autoimmune Inner Ear Disease (AIED) 1.2. Menière’s Disease (MD) 1.3. Bilateral Vestibulopathy (BVP) 1.1. Autoimmune Inner Ear Disease (AIED)

• AIED: part of group of neurosensory HL, <1% • Rare: incidence 5/100,000 people per year • Prevalence higher in women age 20–50 • 15–30% of cases associated with systemic AI disease • Rapidly progressive, often fluctuating bilateral SNHL, evolves over a period of weeks or months, initially responds to immunosuppressive tx • SNHL at least 30 dB, evidence of progression in at least one ear in two successive audiograms performed over 3 months • 80% bilateral, second ear occur after months or years • Vestibular disorders coexist 50%, tinnitus 25% • Clinical outcomes very similar to MD Pathogenesis of AIED

• Linked to self-aggression by T lymphocytes against specific IE Ags, formation of circulating autoAbs • Demonstration of autoAbs against IEAgs very difficult in AIED for 3 reasons: • Lack of specificity of autoAbs in affected patients • Very low percentage of circulating autoAbs • Impossibility of performing dx bx of tissues involved in human in vivo • Impossibility of having direct evidence • Dx of AIED mainly based on Witebsky postulates • Indirect tests in animal models (autoAbs and autoreactive T lymphocytes) • Circumstantial evidence, such as association with other AI diseases • Lymphocyte infiltration of the cochlea • Genetic correlation, and • Response to immunosuppressive tx AutoAbs studied in AIED

• Some of ubiquitous type, e.g., HSP70 and collagen type II • Others specific IE Ags: cochlina, β-tectorin, connexin 26, etc • Cochlina mainly located in spiral ligament, major component of extracellular matrix of IE after collagen • β-tectorin present in HCs, support cells, and tectorial membrane • Activated T lymphocytes enter cochlea, exercising immunological surveillance • Transfer within cochlea of CD4+ T lymphocytes activated with cochlina and β-tectorin Ags causes hypacusia in mouse model

Dx of AIED:

• No reliable specific tests, based on clinical evaluation and experience • Suspected whenever patient with rapidly progressive idiopathic SNHL • García-Berrocal et al proposed criteria: confirm dx of AIED • Rate of auditory recovery after therapy calculated as: 푖푃푇퐴−푓푃푇퐴 푟푎푡푒 = × 100 % 푖푃푇퐴−푐표푛푃푇퐴 (iPTA=Initial auditory threshold, fPTA = final auditory threshold, and conPTA = auditory ear contralateral threshold) García-Berrocal et al [2005]

Major criteria: Minor criteria: • (i) Bilateral HL • (i) Unilateral HL • (ii) Systemic AI disease • (ii) Young or middle-aged • (iii) ANA title > 1:80 • (iii) Female • (iv) Reduction of T-naive • (iv) Auditory recovery with tx < lymphocytes (CD4RA) 80% • (v) Auditory recovery with tx > 80%

At least 3 major, or 2 major + 2 minors PE in AIED

• Otoscopy: generally normal, • Lesions of skin or cartilages of OE occur in relapsing polychondritis • Lesions of TM, ME, and mastoid: observed in Wegener’s granulomatosis • Vestibular symptoms 50%: acute vertigo, disequilibrium, ataxia, and paroxysmal positional vertigo • Tinnitus and auricular fullness 25-50% • DDx: bilateral MD, ototoxic drugs (gentamicin, cisplatin, etc.), enlarged vestibular aqueduct syndrome, Lyme disease, otosyphilis, toxoplasmosis, Charcot-Marie-Tooth disease, and intracranial hypertension No specific serological test

• Several studies for a serological test applicable to AIED • In mid-nineties, a 68 kDa protein isolated from Western blot in serum of some patients with AIED and MD, subsequently identified as Ab to heat shock protein 70 (HSP70) • Marketed under the name of OTOblot, positivity as being predictive for a good response to steroid tx. Unfortunately, OTOblot proved to be a test with very low sensitivity and controversial specificity; subsequent studies shown Ab binds the 68 kDa antigen of bovine cochlea, not humans, resulting in nonspecific ear protein • Probably Ag target anti-68 kDa Ab not HSP70 (as believed in last 15 years) but choline transporter-like protein 2 (CTL2) • Screening systemic AI diseases: antinucleus antibodies (ANA); serum immunoglobulins G, A, M; C3 and C4 complement factors; and immunophenotype of peripheral blood lymphocytes (PBL)

AIED: Immune Biomarkers, AV Aspects, and Therapeutic Modalities of Cogan’s Syndrome. J Immunol Resear, 2018 AIED: treatment

• Corticosteroid drugs: the first-choice tx for AIED, but immunosuppressive and immunomodulatory drugs used as adjuvant or second-choice tx • Corticosteroids: an anti-inflammatory, immunosuppressive, and regulation mechanism in electrolyte balance in cochlea, also mineralocorticoid action • Dosage and duration variable, some protocols recommend 60 mg/day of prednisone (or 1 mg/kg/day) continued at least 4 weeks; if a good hearing recovery obtained, advised to continue with a maintenance dose at least 2 months before gradual dosage reduction • If no auditory improvement after 4 weeks at full dosage, tx suspended • Response of AIED, varies between 15 and 50% • Necessary to repeat course of corticosteroids in case of relapses of HL or vertigo • Association of AIED with systemic AI disease requires continuation of steroid tx for at least 1 year • Limits of long-term high-dose steroid therapy linked to side effects AIED: treatment

• Use of immunosuppressive drugs in AIED, including methotrexate, cyclophosphamide, and azathioprine • Methotrexate (1990s): second-choice tx in cases of poor HL after steroid tx • Multicentric RDBCT (2003): methotrexate no more effective than placebo for HL • Cyclophosphamide: effective but limited therapeutic alternative with important side effects: pancytopenia, infections, hemorrhagic cystitis, bladder cancer, and infertility • Biologic drugs: tumor necrosis factor (TNF) inhibitors – good efficacy, little side effects, rapid action (from hours to days), contraindicated in active infections • Infliximab (Remicade): good effectiveness when applied in forms of AIED associated with other organ diseases • Etanercept (Enbrel): controversial results AIED: treatment

• Underway for intracochlear administration of drugs or other substances, using different technologies: micropumps with endocochlear catheters, nanoparticles, and viral vectors • Recently, vectors consisting of genetically modified monocytes/macrophages been hypothesized, based on ability of circulating monocytes and macrophages to be recruited into IE in a condition of inflammation • “Intracochlear drug delivery” techniques allow a high and generally well- controlled concentration of drug in IE, reducing systemic effects • Careful in vivo experiments required before clinical use • Methods of intracochlear administration take advantage of permeability of round window, intratympanic injection or insertion of drugs soaked in fenestral region after surgical lifting of TM under local anaesthesia If AIED not respond to immunosuppressive tx

• Evolution of HL must be carefully monitored with IE MRI • Fibrosis and ossification of cochlea can evolve rapidly even within a few weeks and only loss of hyper-intensity of labyrinthine liquids in T2 sequences , or image of initial ossification to CT, allows timely recognition of these processes • Application of cochlear implant (CI) must take place before fibrosis prevents insertion of electrode cable into cochlea • Correct timing of CI: decision that requires close cooperation b/w ENT surgeon, rheumatologist, and radiologist • Delay in recognition of cochlear fibrosis permanently preclude rehabilitation of deep deafness or cophosis 1.2. Menière’s Disease (MD)

• Idiopathic endolymphatic hydrops • Triad: fluctuating vertigo, tinnitus, and SNHL with aural fullness • Guidelines (1995) diagnoses “definite” “certain” “possible” and “probable” • Exact aetiology /pathogenesis mechanism: unclear, certainly caused by multiple factors; AI a significant role, allergic, genetic, traumatic, or infectious (viral) • AI Less than 20% (6% of unilateral and 16% of bilateral forms) • High prevalence of systemic AI diseases in MD than in gen pop • Bilateral presentation in 25–40% of patients • Good efficacy of glucocorticoids and anti-inflammatory tx • Experimentally inducing hydrops by injection of Ags or monoclonal Abs MD

• Confirmed elevated levels autoAbs or circulating IG complexes and Ag-Ab reactions • Most cases sporadic, a familial form been described, 2.6 to 23.5% • Familial MD (FMD): at least 2 family members (1st or 2nd degree) fulfill definite or probable, most – autosomal dominant (AD) pattern • FMD – clinical heterogeneity: mitochondrial and recessive inheritance in some • Linkage studies in FMD found candidate loci at 5q14–15 in a German family and 12p12.3 in a large Swedish family [34], no genes identified • By exome sequencing: identified mutations in DTNA and FAM136A genes in an AD Spanish family with MD segregating phenotype in 3 women in consecutive generations • DTNA encodes alpha-dystrobrevin, a dystrophin-associated protein which interacts with transmembrane proteins and actin in basolateral membranes of epithelial cells, and it is associated with tight junction reorganization • Genetic factors: one of causes of AI or increased immune reaction in MD • First gene locus associated with sporadic MD identified using a genotyping array: 6p21.33, through nuclear factor kB (NF-κB) and TWEAK/Fn14 pathway • Potential sites of inflammatory damage: BLB, endolymphatic sac, spiral ligament, and reticular lamina of cochlea • This genotype develop bilateral MD through a mediated NF-κB inflammatory response Endolymphatic sac / Stria vascularis Delayed endolymphatic hydrops (DEH)

• DEH: 2ry EH /2ry MD occurs suffering longstanding HL in one ear • HL by various causes: idiopathic, infectious, traumatic, etc. • Classification still controversial in international literature • DEH considered as Some Japanese and German authors: distinct pathology • DEH mostly occurs in ipsilateral ear, with episodic vertigo, less frequently in contralateral ear, with fluctuating hearing loss and recurrent vertigo • Symptoms, dx and tx identical to MD • In a few families, both unilateral HL and DEH have a genetic aetiology, showing AD transmission with incomplete penetrance 1.3. Bilateral Vestibulopathy (BVP)

• In 1989, Baloh “idiopathic bilateral vestibulopathy” • Prevalence in adults: 28/100,000 • Mean age of onset: 50–60 years; dx delay due to unclear S/S • BVP develops in most cases slowly and progressively; initial phase, recurrent short-term episodes of vertigo, with or without association of HL • Both labyrinths and/or vestibular nerves can be affected, simultaneously or sequentially • Symptoms caused by sensory vestibular impairment leading to insufficient VSR • Negative impact on social and physical functions, decay of health-related QOL in 90% • Dx based on patient anamnesis (movement dependent postural imbalance and unsteadiness of gait) and clinical finding (bilaterally reduced or absent function of VOR) • Symptoms exacerbated in darkness and on uneven ground, depend on visual and somatosensory control, disappear under static conditions • Some present movement-induced oscillopsia: during rapid head turns Dx criteria for BVP: The Classification Committee of the Bárány Society (a) Chronic vestibular syndrome with following symptoms: unsteadiness when walking or standing plus at least one of 2 or 3; movement-induced blurred vision or oscillopsia during walking or quick head/body movements; and worsening of unsteadiness in darkness and/or on uneven ground (b) No symptoms while sitting or lying down under static conditions (c) Bilaterally reduced or absent angular VOR function documented by bilaterally pathological horizontal aVOR gain <0.6, by video-HIT or scleral-coil technique, and/or reduced caloric response, and/or reduced horizontal aVOR gain <0.1 upon sinusoidal stimulation on rotatory chair and phase lead >68° (d) Not better accounted for by another disease

Strupp et al., J Vest Resear, 2017 BPV

• Etiology unknown >70% of cases, genetic 15–25% • Most frequent causes: ototoxic drugs, bilateral MD, AI diseases, infections, tumors, bilateral labyrinth contusion, and vascular abnormalities • 20% BVP associated with gangliopathy, as CANVAS (cerebellar ataxia, nonlength-dependent sensory neuropathy, vestibular areflexia) • 50% idiopathic BVP present with migraine according IHS criteria • 23.4% idiopathic BVP – AI disorders in medical history; not always cause BVP directly, AI response could have a modulating role • Most patients presented COCH gene mutation • Mutation identified to cause AD nonsyndromic HL accompanied by vestibular disorders (DNFA9) 2. AV Pathology associated with Systemic AI

2.1 Behçet’s Disease (BD) 2.11 Rheumatoid arthritis 2.2 Cogan’s syndrome (CS) 2.12 Polyarteritis nodosa 2.3. Sarcoidosis 2.13 Takayasu’s arteritis 2.4 Autoimmune thyroid disease (AITD) 2.14 Susac’s syndrome (Graves’ disease, Hashimoto’s thyroiditis) 2.15 Sjogren’s syndrome 2.5 Vogt-Koyanagi-Harada Syndrome (VKH) 2.16 Myasthenia gravis 2.6 Relapsing Polychondritis (RP) 2.17 Multiple sclerosis 2.7 Systemic Lupus Erythematosus (SLE) 2.18 Giant cell arteritis 2.8 Antiphospholipid Syndrome (APS) 2.19 Ulcerative colitis 2.9 IgG4-Related Disease (IgG4-RD) 2.20 Mixed cryoglobulinemia 2.10 ANCA-Associated Vasculitides (AAV) (Wegener’s granulomatosis)

IE Involvement in AI Diseases

• Growing interest, estimated less than 1% of all acquired HL • AV dysfunction presenting a constellation of symptoms consistent with systemic AI or with a preexisting dx of AI disease • Follows gender and demographic characteristics of AI disorders, • Higher prevalence in female between 30s – 50s • Correct identification– essential for possibility of near-complete hearing restoration with appropriate tx • Often misdiagnosed due to variable clinical presentation, limited knowledge, sparse evidence, and lack of specific diagnostic tests Pathophysiology of IE Involvement in AI Diseases • Unclear, related to circulating Abs against a number of IE Ags leading to Ab- dependent cell mediated cytotoxicity, activation of complement system, direct action of cytotoxic T cells, or immune complex mediated damage • Immune complex deposition play a central role; leads to vasculitis of IE vessels that determines atrophy of stria vascularis and SNHL • Deposition of immune complexes reduces calibre of auditory arteries with consequent BF reduction induces oxygen deficit that increases the ROS level responsible for damage to HCs and spiral ganglion • Major factor involved in cochlear and vestibular damage in systemic AI diseases, affecting labyrinthine artery, common trunk of IE vascularization system • Vascular ischemia, underlying vasculitis, initially determines the atrophy of stria vascularis and HC death; progression of inflammation initiates bone inflammatory processes: necrosis or cochlear fibrosis, more evident in final stages of disease AV Symptoms in Systemic AI Diseases

• Different clinical presentations with high interindividual variability • HL: most common, followed by tinnitus and vertigo • Characteristics of HL extremely variable • Typically SNHL, mainly high frequencies • Low-frequency and mid-frequency HL: common in cases of vasculitis • General pattern of SNHL: rapidly progressive over a period of weeks to months, with great timing variability among different systemic diseases • Fluctuations in hearing common, overall course progressive deterioration • HL mainly bilateral and asymmetric; however, cases of unilateral SNHL that manifests in contralateral ear after a variable time been described • Some cases, a temporary and acute BF reduction in IE related with onset of SSNHL, with complete or partial recovery after restoration of normal perfusion • Sudden SNHL: common following systemic AI diseases, presenting symptom in some cases • Despite HL being mainly SNHL, AI diseases also induce CHL • CHL follow ME effusions, ET mucosa inflammation or ossicular chain involvement • Tinnitus mainly found in association to HL, established decrease of peripheral input following HL trigger neuroplastic reactions up to auditory cortex responsible for onset of tinnitus • Vestibular symptoms: rotational vertigo or disequilibrium, follow temporary occlusion of labyrinthine or anterior vestibular artery, mimic – MD AV in Systemic AI: Workup

• Entity of AI damage: inflammatory process in IE or direct macrophage aggression of IHCs/OHCs • SNHL most common auditory symptom of systemic AI diseases, different presentation forms (sudden or progressive) and severity (mild to severe) of SNHL • Early correlation b/w AV symptom and systemic AI disease may be difficult • AV symptoms common to other conditions: DM, HT, Ototoxics • DDx of cause of AV involvement is importance • Dx process of AV symptoms begin with medical hx /family hx followed by traditional AV tests • Audiological test battery include PTA extended to HF region, TEOAE/DPOAE, and ABR • Vestibular testing include basic vestibular exam integrated with caloric test, video HIT, VEMPs • The onset of AV symptom and during FU to monitor the course of disease • AV examination integrated, when AI condition suspected, with specific blood tests AV Symptoms in Systemic AI: Treatment

• Tx of AV symptoms aim at preserving the function: HL as hearing preservation and/or restoration in patients with SNHL, and at solving disability, distress, QoL • Underlying AI disease is suspected, tx be started after complete blood exams • Steroid therapy, commonly used as first-line tx for SSNHL and other AV symptoms, effect on underlying systemic AI disease and delays its diagnosis • In systemic AI disease: tx of AV symptoms usually strictly related to that of systemic condition • Common tx options for systemic AI diseases present AV involvement • Most common tx SSNHL: systemic or intratympanic administration of high doses corticosteroids, associated with hyperbaric oxygen tx in SLE, APS, and TA • Other include antioxidant compounds to avoid progression of SNHL • Hearing aids to support residual hearing function, or • Cochlear implants in case of severe and profound SNHL AV symptoms in Systemic AI disease: Treatment AV symptoms in Cogan’s disease: Treatment AV Symptoms in Systemic AI: Treatment

• Tinnitus approaches aimed to restore hearing function • Antidepressant drugs when a psychological involvement • Oral supplements: combine antioxidants and vasoactive substances • Vertigo treated with high doses corticosteroids associated to betahistine, a strong H3 receptor antagonist /weak H1 receptor agonist, improves vascularization of IE • Additional therapeutic: metoclopramide and antidepressant drugs (inhibitor of D1 receptor) act on central function by reducing sensation of vertigo, nausea, and GI symptoms • For chronic dizziness, specific rehabilitation tx to favor central vestibular compensation and restore normal balance function Conclusions

• AV symptoms found in a variety of AI diseases: rare, underestimated in general population • No specific dx tests able to identify presence of AI or immune-mediated diseases in IE, early Dx essential to increase chances of restoration when specific tx promptly initiated • Two subgroups: 1) immune-mediated AI IE (AIED, MD, BVP), and 2) AV symptoms in systemic AI diseases • Aware of AV symptoms, progressive/ fluctuating SNHL with no other explainable cause, every time suspects an AI disease, with specific oriented questions • AV involvement in AI diseases ascertained by history, clinical findings, an immunologic evaluation of patient’s serum, response to immunosuppressive tx, exclusion of other causes and predisposing factors: noise exposure, ototoxic, previous ear surgery, trauma, meningitis, or family history HL • Exclusion of concomitant conditions may be challenging, in case of presbycusis- or noise-induced HL • AV symptoms could play a role in dx process of AI diseases as early onset or only symptom—of AI condition, and useful to monitor progression of systemic disease • Systemic AI diseases always be considered in patients with AV symptoms • Low prevalence, heterogeneity of studies, and absence of RCT limit knowledge of IE involvement in systemic AI diseases along with underestimation of problem and consequent undertreatment • ENT specialists need to perform a complete clinical-instrumental evaluation: hearing test and vestibular bedside examination, and further specific vestibular tests, such as VNG, posturography, and VEMPs • A close collaboration b/w rheumatologists, radiologists, and otolaryngologists essential to recognizing patients with indication to systemic tx • Timely and adequate medical tx allow recovery of AV damage in most cases • However, evolution of HL and vertigo carefully monitored because fibrosis and ossification of IE rapidly within a few weeks • New classifications lead to use of effective immunological tx, such as biological drugs • New molecules and above “intracochlear drug delivery” methods currently being tested will allow a more effective, personalized tx with fewer side effects Reference

• Girasoli et al. Update on Vertigo in Autoimmune Disorders, from Diagnosis to Treatment: Review Article. J of Immunology Research, 2018, Article ID 5072582, 16 pages. https://doi.org/10.1155/2018/5072582 • Ralli et al. Audiovestibular Symptoms in Systemic Autoimmune Diseases: Review Article. J of Immunology Research, 2018, Article ID 5798103, 14 pages. https://doi.org/10.1155/2018/5798103 • Shamriz et al. Autoimmune Inner Ear Disease: Immune Biomarkers, Audiovestibular Aspects, and Therapeutic Modalities of Cogan’s Syndrome: Review Article. J of Immunology Research, 2018, Article ID 1498640, 8 pages. https://doi.org/10.1155/2018/1498640