Wednesday March 11th, elevated liver enyzmes

A classic internal medicine topic is elevated liver enzymes. Patients can have this picked up by the family doctor or can come in the hospital feeling unwell.

We discussed liver enyzmes vs liver function tests.

Liver function

INR - coagulation

Bilirubin - produce in the liver, stored in the gallbladder, helps emulsify fats for digestion, ultimately gives stool its brown colour

Albumin - helps with oncotic pressure, binds a variety of hormones

Breaks down toxins (thus potentially getting encephalopathic)

Gluconeogenesis - hypoglycemia common in fulminant hepatic failure

Enzymes

AST - also present in skeletal and cardiac muscle

ALT - more specific to the liver

Alk phos - cholestatic pattern, also comes from bones, osteoblastic activity, placenta

GGT - cholestatic but also increased with ETOH consumption,

LDH - present in all cells, but will be elevated in hepatocellular damage

Our generally approach is looking for a hepatocellular vs cholestatic patterns, the latter having more increased alk phos and bilirubin.

Ultrasound can show dilated ducts to suggest obstruction.

The Thousands club

The differential for elevated liver enzymes is impressive and with all cases you should probably pull up the list while you consider differentials in your patient. 

Patients with liver enzymes in the thousands points us in a particular differential:

hepatic vein or portal vein thrombosis (budd chiari), viral hepatitis (hep A, B, EBV, CMV), drugs (tyelnol, isoniaizd, go over all new meds), ischemic (episodes of hypotension), autoimmune, wilsons disease (apparently).

Of note, alcohol alone will essentially NOT cause enzymes to be greater than 1000, so even if positive, look for other causes!

Im sure there are case reports of things like hemochromatosis presenting the thousands, but your ferritin will be elevated with "inflammation" so thus a tsat of >55 could lead you in that direction.

The American Gastroenterology association is coming out with new guidelines in 2016, Canadian guidelines are really old, and AAALD don't have guidelines directly about elevated liver enzymes.

Here is a decent review published in 2011 on elevated liver enzymes
http://www.aafp.org/afp/2011/1101/p1003.html