Human Leukocyte Antigen (HLA) Influence on Prognosis of Autoimmune Hearing Loss

Blood tests as biomarkers for the diagnosis and prognosis of sudden sensorineural hearing loss in adults: a systematic review

OBJECTIVE

Sudden sensorineural hearing loss is considered idiopathic in up to 90 per cent of cases. This study explored the role of blood tests as biomarkers for the diagnosis and prognosis of sudden sensorineural hearing loss.

METHOD

Two researchers filtered 34 papers into the final review. This review was pre-registered on the Prospero database and conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines.

RESULTS

Raised inflammatory markers are almost universal in sudden sensorineural hearing loss, suggesting an inflammatory or autoimmune process. The most useful biomarkers are neutrophil-lymphocyte ratio, platelet-lymphocyte ratio and fibrinogen level. Focused investigations should be deployed on a case-by-case basis to identify underlying metabolic, infective and autoimmune conditions.

CONCLUSION

A full blood count and coagulation screen (fibrinogen) is recommended in all cases of sudden sensorineural hearing loss. These are inexpensive, accessible and offer as much diagnostic and prognostic information as any other biomarker. There is emerging evidence regarding specific biomarkers for sudden sensorineural hearing loss prognosis, with heat shock protein-70, anti-endothelial cell antibody and prestin demonstrating potential; investigation of their validity through prospective, controlled research is recommended.

Prevalence of hearing loss in patients with Sjögren syndrome: a systematic review and meta-analysis

Sjögren syndrome (SS) is a multisystem autoimmune disease, primarily targeting salivary and lacrimal glands; skin, nasal and vaginal dryness, along with musculoskeletal pain and fatigue are the most commonly reported symptoms. Hearing loss is hypothesized to be frequent as well. The purpose of this systematic review was to estimate the prevalence of Hearing loss and its different subtypes in patients with Sjögren syndrome. PRISMA guidelines were followed to ensure highest quality for our systematic review. A random effects model meta-analysis and meta-regression was conducted using I² as heterogeneity indicator. Eleven observational studies were included in this systematic review. Ten of them were cross-sectional, while one study was case-control. Studies were assessed for risk of bias: all were rated to a moderate level, except for two rated to a low level. Pooled prevalence of any type of hearing loss was 52.2%. After excluding studies rated to moderate bias, the pooled prevalence of hearing loss was 36.7%. We also conducted a subgroup analysis depending on type of hearing loss. Pooled prevalence of sensorineural hearing loss was 42.6%., while pooled prevalence of conductive hearing loss and mixed hearing loss were 5% and 2.3%, respectively. Meta-regression was conducted in an effort to identify possible variables capable to explain high heterogeneity between studies. Sample size and year of study were separately found to account for a portion of heterogeneity between studies of sensorineural hearing loss. Year of study was also found to account for a portion of heterogeneity between studies of conductive hearing loss. In conclusion, sensorineural hearing loss, is highly prevalent in patients with Sjögren syndrome. On this basis, early screening and follow-up of patients with Sjögren syndrome by pure tone audiometry is important.

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

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

Recurrent sudden sensorineural hearing loss—A literature review

Objective

Sudden sensorineural hearing loss (SSNHL) is one of the few emergent otologic conditions. Although more than half of all patients would benefit from timely treatment, recurrence occasionally develops unexpectedly. The aim of our study is to evaluate the recurrence rate after SSNHL, and present the prognosis after first‐episode and recurrent SSNHL.

Methods

A literature search was conducted of the PubMed and Embase electronic databases.

Results

Seven studies with a total of 3781 patients were included, and 96 patients experienced recurrence. The recurrence rate ranged between 1.4% and 17%. The average time to recurrence was about 2 years in most studies. The majority of the studies reported using systemic steroids for treating first‐episode SSNHL, and one study used a plasma expander in patients with recurrent SSNHL. The recovery rate for first‐episode patients was 58%–79%, while that for recurrent SSNHL ranged widely, from 21% to 86%. There were no common risk factors for SSNHL recurrence among the studies, although low‐frequency hearing loss, the presence of tinnitus during follow‐up, and an increased neutrophil‐to‐lymphocyte ratio and platelet‐to‐lymphocyte ratio have been proposed.

Conclusion

Understanding the recurrence rate, risk factors, and prognosis after recurrence of SSHNL is crucial for comprehensive medical care; in this respect, further prospective studies with long‐term follow‐up may be instructive.

Level of Evidence

4