From the Guidelines
Autoimmune hearing loss is primarily caused by the immune system mistakenly attacking the inner ear structures, with autoimmune inner ear disease (AIED) being a direct cause, as well as other autoimmune disorders like rheumatoid arthritis, lupus, and Sjögren's syndrome. The most common causes of autoimmune hearing loss include:
- Autoimmune disorders like rheumatoid arthritis, lupus, and Sjögren's syndrome that can affect the ear as part of systemic inflammation 1
- Cogan's syndrome, which specifically targets the inner ear and eyes
- Wegener's granulomatosis, which affects blood vessels including those in the ear
- Autoimmune inner ear disease (AIED), which directly attacks the cochlea and vestibular system Other contributing factors include:
- Genetic predisposition
- Viral infections that trigger abnormal immune responses
- Certain medications that can induce autoimmune reactions The mechanism involves antibodies or immune cells attacking proteins in the inner ear, causing inflammation that damages the delicate hair cells and structures needed for hearing, as noted in the context of sudden sensorineural hearing loss (SSNHL) 2. This damage disrupts the conversion of sound waves into nerve signals, leading to progressive, often bilateral hearing loss that may fluctuate but typically worsens without treatment. Early diagnosis is crucial as prompt immunosuppressive therapy with corticosteroids like prednisone or steroid-sparing agents like methotrexate or cyclophosphamide can help preserve hearing function.
From the Research
Causes of Autoimmune Hearing Loss
- Autoimmune diseases such as systemic lupus erythematosus (SLE), granulomatosis with polyangiitis (GPA, Wegener's granulomatosis), and rheumatoid arthritis (RA) have been linked to hearing loss 3
- A proposed pathogenic mechanism of autoimmune inner ear disease (AIED) involves inflammation and immune-mediated attack of specific inner ear structures, leading to an excessive Th1 immune response with vascular changes and tissue damage in the cochlea 4
- Self-reactive T cells and immunoglobulins have been identified, and immune-complex deposition, microthrombosis, and electrochemical disturbances causing impaired neurosignalling have been implicated in the pathogenesis of AIED 4
- Abnormalities in the cytokine milieu have been demonstrated in subjects with AIED, which may prove a target for therapy in the future 4
- Sensorineural hearing loss has been significantly related to autoimmune diseases such as SLE, RA, and vitiligo 5
- The presence of antinuclear antibodies (ANA) may justify performing a complementary investigation to determine the presence of a systemic autoimmune disease (SAID) 6
Associated Factors
- Cumulative steroid dose and number of organ manifestations have been correlated with hearing loss in GPA and SLE patients 3
- Bilateral hearing loss has been associated with a worse outcome, while a normal audiometry or mild hearing loss at the time of diagnosis has been associated with a better outcome 6
- The use of systemic corticosteroids, transtympanic corticosteroids, and non-steroid immunomodulator drugs has not been shown to affect prognosis 6
- Cochlear fibrosis or ossification has been found to affect 50% of implanted ears in patients suffering from autoimmune and immune-mediated SNHL, highlighting the importance of earlier implantation 7