Thanks to John for presenting the case of a middle aged man from Vietnam with history of smoking who presented to the hospital with painless jaundice with imaging concerning for malignancy, found to have IgG4 related autoimmune pancreatitis!

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Clinical Pearls

• For imaging of the biliary tree:
  • Ultrasound is best for stones
  • CT is better for parenchymal disease
  • ERCP/MRCP is best for intraductal masses or stones
• IgG4 related disease is more common in men >50 years of age.  It can affect many organs, similar to sarcoid.
• It is an inflammatory and fibrotic systemic conditions where organs form tumefactive lesions rich in IgG4 plasma cells.
• Diagnosis requires biopsy.  Serum IgG levels may be normal even in active disease.  However, a significantly elevated level is highly sensitive/specific (>95%) for IgG4 related disease.
• Treatment involves steroids + immunomodulating therapy.

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Approach to high bilis!

DDx for painless jaundice:

• Cancer (pancreatic, cholangiocarcinoma)
• Meds/toxins
• Viral hepatitis
• ESLD
• CHF
• Hemolysis
• PBC/PSC

IgG4 related disease

• First described in 2003
• Majority men (62-83%) and > 50 years of age.
• Inflammatory and Fibrotic systemic condition where organs have tumefactive (tumor forming) lesions with an infiltrate rich in IgG4 plasma cells and often elevated IgG4 serum levels (but not always!)
• The pathophys is poorly understood but thought to be a combination of autoimmune and allergic mediated processes.

Clinical features:

• Subacute onset, typically few systemic signs/symptoms
• 30% of those with autoimmune pancreatitis also have tubulointerstitial nephritis at presentation.
• Pancreatic involvement 
  • Manifestations include a uniformly enlarged pancreas (sausage pancreas on imaging), pancreatic mass which can mimic cancer, recurrent pancreatitis, or strictures.
• Biliary involvement
  • Biliary strictures leading to obstructive jaundice as well as sclerosing cholangitis
• ANY organ can be affected (eg: thyroiditis, interstitial nephritis, salivary involvement), much like sarcoid

Spectrum of IgG4-related disease

Diagnosis:

• Need tissue biopsy for diagnosis.  Serum serologies are only suggestive.

Treatment:

• Steroids + immunomodulating therapy.  

Chronic pancreatitis

Etiologies of Chronic Pancreatitis (progressive inflammatory changes in the pancreas that result in permanent structural damage and histologic fibrosis)

• Alcohol abuse(45%) as well as cigarette use
• Recurrent acute pancreatitis
• Genetic (eg: CFTR, SPINK mutations)
• Chronic ductal obstruction
• Systemic diseases (eg: SLE, hyperparathyroidism, hypertriglyceridemia)
• Idiopathic
• Autoimmune: Can be Type 1 (part of IgG4 related disease) or Type 2 (idiopathic) 

Clinical manifestations of chronic pancreatitis

• Can be ASYMPTOMATIC
• Epigastric abdominal pain most common symptom however
• Pancreatic insufficiency (only after 90 %of pancreatic function lost) and manifests as steatorrhea and glucose intolerance/diabetes
• Remember that chronic pancreatitis puts you at increased risk for PANCREATIC CANCER

Lab/Imaging

• Amylase/Lipase usually NORMAL so not as helpful
• 72 hour quantitative fecal fat (steatorrhea alone is non-specific!)
• Fecal elastasehas high sensitivity and specificity for chronic pancreatitis
• KUB can show calcificationshinting towards chronic pancreatitis and MRCP/ultrasound can show pancreatic duct obstructions, dilations, strictures or fluid collections

Treatment

• Alcohol and smoking cessation!
• Creon supplementation, may also need fat-soluble (A,D,K,E) supplementation
• Analgesics for abdominal pain which is extremely hard to control. Minimize opioids but may be necessary for refractory pain.
• Specialized approaches include celiac nerve blocks, endoscopic surgery and surgical resection