APT: Liver
This week we will be discussing the Liver and Bile Collecting system. Please review NEJM review articles on cirrhosis, acute liver failure, and ACG clinical guidelines for LFT interpretation/work up to help prepare.
Approach to Liver chemistries:
ALT: 33 (males), 25 (females), ALP: 115 (males), 100 (females)
Hepatocellular: ALT and AST both up
Cholestatic: ALP up and also direct hyperbilirubinemia
Infiltrative: ASLT up without significant bilirubin or AST or ALT elevation
Non-hepatic: Isolated AST elevated, indirect hyperbilirubinemia
Any degree of AST/ALT elevated:
meds/toxins (aceteaminophen, certain abx, INH, MTX, NSAIDs, heparin, amiodarone, steroids, augment, sulfa drugs, allopurinol, etc)
Alcohol related (alcoholic hepatitis usually >2:1 AST:ALT ratio)
viral infections (Hep A-E, EBV, CMV, VZV, HSV)
Sepsis /ischemia
Biliary obstruction (mixed picture)
NAFLD (usually AST and ALT elevated but <4x ULN)
If above: Workup includes, but not limited to:
stop offending medications/toxins
viral hepatitis serologies
RUQ US (steatosis, cirrhosis, fibroscan)
ANA, ASMA, LKM-1, IgG, Ceruloplasmin, urinary copper, Fe/TIBC >45%, ferritin >200,
Extreme elevation (AST/ALT >1000s, indicates some acute process)
Ischemia (Shock, cardiac arrest, Budd-Chiari, usually AST/ALT goes up first then bilirubin increases)
Meds/toxins (acetaminophen toxicity)
Acute viral infection (Hep A-E, consider HBV reactivation)
autoimmune hepatitis
acute biliary obstruction
If above, workup includes, but not limited to
INR, assess for hepatic encephalopathy, acute liver injury/failure
stop offending meds/toxins, consider activated charcoal, N-acetylcysteine
viral serologies
RUQ US with dopplers
Cholestatic injury pattern (Increased ALP and biliriubin)
Biliary obstruction (Choledocholithiasis, malignancy, primary sclerosis cholangitis, chronic pancreatitis w/ strictures)
intrahepatic cholestasis: Medications (penicillin, cephalosporins, anabolic steroids, bactrim, TPN, sepsis, primary biliary cholangitis (PBC)
If above, workup with include, but not limited to
RUQ US for obstruction
MRCP or ERCP
+/- liver biopsy
Infiltrative pattern (primarily ALP elevation)
sarcoidosis or other granulomatosis (Tb)
Malignancy (lymphoma, mets to liver, HCC)
Amyloidosis
abscess
If above, workup includes, but not limited to
GGT, imaging with RUQ US or CT, MRCP
Consider SPEP + IgG4
+- liver biopsy
Acute Liver Failure
King’s College Criteria
Acetaminophen induced liver failure: pH <7.3, or ALL 3 of INR > 6.5, Cr > 3.4, grades 3-4 Hepatic encephlopathy
All other causes of ALF: INR >6.5 OR 3/5 of the following: age <10 or >40, Tbili >17, INR >3.5, time from jaundice to encephalopathy >7d, unfavorable etiology (Seronegative hepatitis, DILI, Wilson’s)
Decompensated Cirrhosis