- A systemic fibro-inflammatory d/o from infiltration of IgG4 producing plasma cells, can affect most organ systems
- Sx caused by interfering w/fxn and/or local enlargement
- Not typically acutely ill, not always progressive
- One or multiple organs affected simultaneously
- May have asthma, eczema, rhino-sinusitis or other allergic features
- Organ specific sx include:
- Generalized/local adenopathy
- Autoimmune pancreatitis→ abdomen pain, wt loss, jaundice
- Peri-orbital infiltration→ swelling, pain
- Nose/sinus→ nasal obstruction, sinus dysfxn, d/c
- Sub-mandibular/parotid→ enlargement or dysfxn
- Hypothalamus/pituitary→ fatigue, ha, wt loss, visual changes
- Thyroid→ increased size, hypothyroidism related sx
- Aorta→aortitis w/aneurysm or dissection
- Retroperitoneum→fibrosis w/ureteral obstruction
- Pulmonary→ progressive sob, cough, DOE
- Kidney→ tubulointerstitial nephritis or membranous nephropathy; symptoms related to degree of kidney dysfunction
- Organ specific enlargement, though this can be otherwise asx
- Findings that are sequelae of organ specific dysfxn→ e.g. epigastric pain w/pancreatitis
- Adenopathy, 1-2cm, non-tender; other based on affected organs
- Biopsy of affected organ(s) reveals lymphoplasmacytic ifiltrate w/IgG4+ plasma cells and fibrosis
- Serum IgG 4 levels are usually (but now always) elevated