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For further information, see CMDT Part 20-15: IgG4-Related Disease
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Essentials of Diagnosis
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Predominantly affects men (75% of patients); average age > 50 years
Protean manifestations caused by lymphoplasmacytic infiltrates in any organ or tissue, especially the pancreas, lacrimal glands, biliary tract, and retroperitoneum
Subacute onset; fever, constitutional symptoms rare
Diagnosis rests on specific histopathological findings that include presence of IgG4-bearing plasma cells
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General Considerations
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A systemic disorder of unknown cause
Any organ of the body can be affected
Marked by highly characteristic fibroinflammatory changes
Severity ranges from asymptomatic to organ- or life-threatening
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Lymphoplasmacytic infiltrates, fibrosis, and phlebitis may be localized or generalized
Enlargement of submandibular glands
Proptosis from periorbital infiltration
Retroperitoneal fibrosis, mediastinal fibrosis
Inflammatory aortic aneurysm
Pancreatic mass with autoimmune pancreatitis
Fever and constitutional symptoms are usually absent
Nearly half of patients also have allergic disorders such as sinusitis or asthma
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Differential Diagnosis
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Diagnostic Procedures
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Initial therapy is usually oral prednisone 0.6 mg/kg/day, tapered over weeks or months depending on response
Because corticosteroid monotherapy may fail to control the disease and can cause significant long-term toxicity, immunosuppressants such as rituximab, mycophenolate mofetil, or azathioprine are often used
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Patients who are asymptomatic and have no organ-threatening disease can be monitored carefully
Spontaneous resolution can occur
The degree of fibrosis in affected organs determines the patient's responsiveness to treatment
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Ebbo
M
et al. Long-term efficacy and safety of rituximab in IgG
4-related disease: data from a French nationwide study of thirty-three patients. PLoS One. 2017 Sep 15;12(9):e0183844.
[PubMed: 28915275]