Advances in biomarkers for differential diagnosis of autoimmune and autoinflammatory inner ear disorders

Autoimmune inner ear disease (AIED) represents a rare yet potentially reversible cause of sensorineural hearing loss, characterized by immune-mediated damage to cochlear and vestibular structures. Unlike autoimmunity, which is driven by adaptive immune responses and autoantibodies, autoinflammation stems from innate immune system dysregulation, typically involving inflammasome hyperactivation. This review synthesizes recent advancements in biomarkers for the differential diagnosis of AIED, emphasizing their role in distinguishing it from conditions such as Meniere's disease (MD) and chronic otitis media (COM). Autoantibodies and cytokines, including anti-heat shock protein 70 (HSP70), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), antiphospholipid antibodies, anti-type II collagen, selective immunoglobulin A deficiency (sIgAD), and anti-cochlin antibodies, have a significant role in diagnostic sensitivity, specificity, and correlations with treatment responsiveness. Additionally, we discuss the utility of magnetic resonance imaging (MRI) in identifying inner ear enhancements and propose diagnostic algorithms to facilitate early detection. By integrating serological, immunological, and radiological insights, this work underscores the potential of these biomarkers to guide personalized therapeutic strategies, including corticosteroids and biologics, while addressing diagnostic challenges and the need for standardized criteria. Ultimately, enhanced biomarker utilization may improve outcomes in AIED by enabling timely intervention and reducing misdiagnosis.