26th February 2025

IgG4-related disease

This is a heterogeneous disease characterised by inflammation and fibrosis. Many of the subtypes were considered separate entities until it became clear that lesions shared histological findings of abundant IgG4-positive plasma cells.

Patients are usually constitutionally well; fever or elevated CRP suggest another disease process. There can be single or multi-organ involvement at diagnosis, and disease progression is variable.

There are four different phenotypes that have been recognised recently:

• Pancreatobiliary: diabetes, exocrine insufficiency, sclerosing cholangitis and autoimmune pancreatitis.
• Head and neck limited: orbital involvement, sinusitis, thyroiditis, cranial nerve palsies and hearing loss. This tends to affect younger women of Asian origin.
• Retroperitoneal: sequelae of retroperitoneal fibrosis, including hydronephrosis, aortitis, and compression of various structures.
• Mikulicz’s (systemic): enlargement of the lacrimal and salivary glands with xerostomia and xerophthalmia, with any of the other features previously described.

Treatment is generally with glucocorticoids, then biologic agents such as rituximab to maintain remission.