Research status of IgG4-related sialadenitis

IgG4-related sialadenitis (IgG4-RS) is a type of autoimmune disease that has been recognized in recent years, and the pathogenesis remains unclear. IgG4-RS mainly affects the submandibular gland and parotid gland and is characterized by diffuse painless swelling of the bilateral salivary glands and/or lacrimal glands, usually lasting more than 3 months. Some patients have accompanying hearing loss or hearing impairment, sinusitis, lymphadenopathy and other symptoms; nearly half of patients have different degrees of salivary gland secretion disorders. Most patients have elevated serum IgG4 levels, but they cannot be used as the only marker for diagnosis. Histopathology remains the “gold standard” for diagnosis. Presently, submandibular gland biopsy is often used for diagnosis. Histopathology showed lymphoplasmacytic infiltration, occlusive phlebitis, striated fibrosis; immunohistochemistry showed IgG4⁺/IgG⁺ plasma cells >40%, and IgG4⁺ plasma cell/high-power field vision > 10. Glucocorticoids are regarded as first-line drugs for the treatment of this disease. Clinically, glucocorticoids are often combined with immunosuppressive agents such as cyclophosphamide, but no standard drug regimen exists. Most patients have a significant short-term treatment effect, and the long-term prognosis requires further study. Patients with a recurrence tendency should adjust the hormone dose over time. In the future, further research is needed regarding the pathogenesis and treatment of the disease to improve the clinical diagnosis rate and therapeutic effect.