IgG4-Related Disease

Clinical history:  Man, 60 years, multiorgan involvement, unique or multiple inflammatory pseudotumor

4 phenotypes:

 • Pancreato-hépato-biliary

 • Retroperitoneum and aorta

 • Head and neck-limited (orbital, extraocular muscle, sinusitis, parotid gland, submandibular gland, lacrimal gland), female, asian

 • Systemic (head and neck, pancreas, biliary, renal, lung, lymph node), high serum IgG4 concentration

PET-CT Imaging (→ Diagnostic orientation, Biopsy orientation):

 • More sensitive than conventional imaging (aorta, salivary glands, lymph nodes)

 • Some false negative (small lesions, meninges, kidneys)

 • Strong correlation with response to treatment and relapse

No specific laboratory tests:

 • IgG4 : nonspecific, absent in 10-30%

 • Polyclonal hypergammaglobulinemia, ↑ acute phase reactants, eosinophilia, ↑ serum lgE, no autoantibodies (antinuclear antibodies, rheumatoid factor), ± hypocomplementemia

Histology - Non-specific:

 • No necrosis, No vasculitis, No granuloma, No monoclonality

 • "Reactive lymphoid hyperplasia with increased IgG4+ cells"

Treatment:

 • Glucocorticoids (0.6 mg/kg/day) - Relapse >40% supporting long-term maintenance with GCs GC-dependency

 • No response to glucocorticoids - reconsider diagnosis (new biopsy+++)

 • 2nd line: No consensus but rituximab more widely used than azathioprine, cyclophosphamide, methotrexate,...



By Dr. Camille Mettler @Mettler_K1000



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