Overview of immunoglobulin G₄ (IgG₄)-related disease

Wallace, 2020Lanzillotta, 2020Löhr, 2020Wallace, 2018Khosroshahi, 2015Deshpande, 2012

Immunoglobulin G₄ (IgG₄)–related disease is a systemic, immune-mediated disease characterised by the development of fibro-inflammatory lesions. Lesions can occur at nearly any anatomical site but most commonly affect the pancreas, biliary tract, salivary glands, orbit and lacrimal glands, retroperitoneum, lungs, kidney and lymph nodes. Little is known about its epidemiology, and no environmental or genetic risk factors have been conclusively linked to the diseaseLanzillotta, 2020.

The disease can occur in all age groups, including children, but middle- and older-aged males appear to be the most frequently affected. Some patterns of organ involvement (eg head- and neck-limited disease) are more frequently observed in females. Mass lesions, consisting of IgG₄–positive plasma cells and fibrosis, are the hallmark pathological features of the disease.