About IgG4-Related Disease (IgG4-RD)

IgG4-related disease (IgG4-RD) is a systemic immune-mediated fibroinflammatory disease with protean manifestations, It is almost always chronic and slowly progressive.

  • Labs (even serum IgG4) has limited utility. Biopsy is the key!
  • Generally very steroid responsive – consider other diagnoses if not responding to steroids
  • Disease relapses are common
  • New disease manifestations can occur over time
  • Rituximab can help considerably
  • Single organ involvement or multi-organ involvement
  • Manifestations include:
    • Salivary and lacrimal gland enlargement
    • Lymphadenopathy
    • Pancreatitis, pancreatic insufficiency
    • Aortitis, retroperitoneal fibrosis
    • Tubulointerstitial nephritis
    • Pleuroparenchymal lung disease
  • Imaging (view images)
  • Biopsy is key! (view image)
    • Lymph node histopathology is often less specific than other tissue in IgG4-RD
  • Lab workup
    • Of limited value for diagnosis
    • Serum IgG4 high, can be supportive of IgG4-RD
    • Other potentially valuable labs include SSA, SSB, ANCA, IGRA, HIV
  • Malignancy on differential due to chronicity of disease, lymphadenopathy, tumefactive lesions
  • If sicca, consider Sjogren’s
  • Early treatment helps prevent additional organ damage
  • Consider osteoporosis treatment/prophylaxis for those on long term systemic steroids