Background
- Refers to a rise in ALP and GGT +/- bilirubin that is much more pronounced than any rise in ALT
- ALP can also come from bone and placenta
Differential Diagnosis
Marked Elevation
- ExtrAhepatic biliary obstruction
- Choledocholithiasis
- Cancer of the pancreas, gallbladder, ampulla of Vater, biliary duct, or perihilar lymph nodes
- Biliary strictures
- Primary sclerosing cholangitis with extrahepatic bile duct stricture
- Procedural complication of ERCP
- Chronic pancreatitis resulting in stricture of the distal bile duct
- Anastomotic stricture of the bile duct after liver transplantation
- Infection: AIDS cholangiopathy, Ascaris lumbricoides, liver fluke
- Intrahepatic cholestasis
- Drugs and toxins
- Primary biliary cholangitis
- Primary sclerosing cholangitis
- Intrahepatic cholestasis of pregnancy
- Benign postoperative cholestasis
- Total parenteral nutrition
- Infiltrative diseases: amyloidosis, lymphoma, sarcoidosis, tuberculosis, or hepatic abscess
- Liver metastases
- Allograft rejection after liver transplant
- Alcoholic hepatitis
- Hepatic crisis of sickle cell disease
- Others: IgG4 cholangiopathy, ischemic cholangiopathy, COVID-19
Investigations
- Liver/biliary ultrasound to help differentiate between extrahepatic cholestasis (if biliary dilatation is seen) versus intrahepatic
- For intrahepatic cholestasis
- First order AMA (for PBC), ANA, anti-smooth muscle antibodies
- Then consider MRCP, hepatitis A, B, C, and E testing, and EBV and CMV testing
- Finally, consider liver biopsy
