DSA: Liver enzymes Flashcards
Liver function tests (LFTs), a misnomer, include what tests?
-
AST/ALT (transaminases)
- aspartate aminotransferase (AST)
- Alanine aminotransferase (ALT
- ALP (alkaline phosphatase)
- Bilirubin
- LDH and GGT
TRUE liver function tests include:
- PT/INR (tests coag factors)
- Albumin
- Cholesterol
- Ammonia
- In hepatocellular injury => _______ in _________ enzymes
- ____ is MORE specific for liver injury
-
↑ AST/ALT
- ALT is MORE specific for liver injury
In cholestatic injury (injury to bile ducts) => _______ in _________ enzymes
- ↑ ALP and bilirubin
In __________, bile cannot reach duodenum.
Cholestatic injury
Signs of cholestatic injury
- Jaundice
- Pruritis (very itchy)
- Pure cholestasis (no signs of hepatocellular necrosis)
On labs, if we see ↑ ALP, indicates problems with _________ or _______.
How do we differentiate?
- Bone or liver (cholestasis)
- To differentiate, measure GGT
- NL GGT = bone
- ↑ GGT = liver (cholestatic)
↑ ALP in NL in _____________.
Childhood, as we are growing and pregnancy
When is ↑ INR problematic?
If a patient is NOT on coumadin/warfarin, then they can have liver disease.
________ is the best test to measure acute hepatic functioning (acute liver failure).
INR
INR measures what?
Deficiency of all cloting factors except factor 8 => liver disease, hepatitis, toxic injury, cirrohosis.
PT prolongation due to fat malasbsoprtion can be distinguished from liver disease by _____________.
Rapid and complete response to vitamin K.
Albumin tests the ________ of the liver.
↓ serum albumin often occurs due to?
- Function of the liver (degree of hypoalbuminia = severity of liver dysfunction)
- ↓ in patients with chronic liver disease
Ammonia tests the ________ of the liver.
↑ blood ammonia often occurs due to?
- Function of the liver
- Hepatic detoxification is not working or acute encephalopthy
↑ indirect-reacting bilirubin, with all other enzymes NL) can be due to __________________.
- Hemolysis (↑ = more than 90% of total bilirubin)
- Gilbert’s syndrome (↑ = more than 90% of total bilirubin)
Associated features with hemolysis (↑ isolated indirect-acting bilrubin)
- Anemia
- ↑ reticulocyte count
- NL enzyme levels (LDH may be ↑)
Associated features with Gilberts (↑ isolated indirect-acting bilrubin)
- Benign course that beings in late adolescence that occurs during fasting
- No abnormal liver tests
- No anemia
Many types of liver disease will have ↑ ___________.
Direct-reacting bilirubin
Non-hepatic reasons for ↑ bilirubin
- RBC (hemolysis, intra-abdominal bleeding, hematoma)
Non-hepatic reasons for ↑ AST
- Skeletal muscle
- Cardiac muscle
- RBC
Non-hepatic reasons for ↑ ALT
- Skeletal muscle
- Cardiac muscle
- Kidneys
Non-hepatic reasons for ↑ LDH
- Heart
- RBC (hemolysis)
Acute (<6 months) abnormal liver ezymes tests that indicate hepatic injury => check for?
- IgM Anti-HAV, [HBsAg & IgM Anti- Hbc], Anti-HCV => Hep A, B, C
- SMA => autoimmune hepatitis
- Mono heterphile => Mono
- Ceruloplasm => Wilsons disease
- Alcohol history => alcoholic hepatitis
- Drug history
Small elevation of AST/ALT => mostly due to _______
nonalcoholic fatty liver disease
Acute (< 6 months) abnormal liver ezymes tests that indicate cholestatic injury => check for?
- AMA => primary biliary cirrhosis
- Drug history
- US/MRI => structural problems, hepatic vein thrombosis
- MRCP/ECRP
Chronic (> 6 months) abnormal liver ezymes tests that indicate hepatitic injury => check for?
- HbsAg and Anti-HCV => Hep B and C
- Fe saturation, ferritan
- Ceruloplasm
- a-AT1
- ANA, SMA => AI hepatitis
- US
- Alcohol history
Chronic (> 6 months) abnormal liver ezymes tests that indicate cholestatic injury => check for?
- Meds
- AMA
- p-ACNA
- US
- MRCP/ERCP
