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IgG4-related systemic diseases

IgG4-related systemic disease mimics many malignant, infectious, and inflammatory disorders. It occurs mostly in older males who frequently have a past or present history of allergic diseases (eczema, asthma).

An elevated serum IgG4 level is seen in 60% to 80% of patients. It can involve multiple organs simultaneously although one organ is usually most prominently affected. The two most common presentations are type 1 autoimmune pancreatitis and salivary gland disease including gland enlargement (Mikulicz disease) and sclerosing sialadenitis (Kuttner tumor) Almost any organ can be involved Chronic lymphoplasmacytic aortitis involving the thoracic more commonly than the abdominal aorta can lead to aneurysm formation. A subset of patients with idiopathic retroperitoneal fibrosis have this disease, usually in conjunction with other organ involvement. Serologies are negative except for the elevated (>135mg/dL) IgG4 level (60% to 70% of cases). Treatment includes high-dose corticosteroids. Azathioprine, mycophenolate mofetil, or rituximab is used for corticosteroid-dependent or corticosteroid-resistant disease. Patients may be at increased risk of developing non-Hodgkin lymphoma.

IgG4-RD associated disorders include:

  • Type 1 (IgG4-related) autoimmune pancreatitis (AIP)
  • IgG4-related sclerosing cholangitis
  • Mikulicz disease (IgG4-related dacryoadenitis and sialadenitis)
  • Sclerosing sialadenitis (Küttner’s tumor, IgG4-related submandibular gland disease)
  • Inflammatory orbital pseudotumor (IgG4-related orbital inflammation or orbital inflammatory pseudotumor)
  • Chronic sclerosing dacryoadenitis (lacrimal gland enlargement, IgG4-related dacryoadenitis)
  • Subset of patients with “idiopathic” retroperitoneal fibrosis (Ormond’s disease) and related disorders
  • Chronic sclerosing aortitis and periaortitis (IgG4-related aortitis or periaortitis)
  • Riedel’s thyroiditis (IgG4-related thyroid disease)
  • IgG4-related interstitial pneumonitis and pulmonary inflammatory pseudotumors (IgG4-related respiratory disease)
  • IgG4-related kidney disease
  • IgG4-related hypophysitis
  • IgG4-related pachymeningitis
  • IgG4-related midline destructive disease





The Lancet

Orphanet Journal of Rare Diseases

NEJM Review Article

Archives of Pathology