LFTs and Results Flashcards
What does a high ALT level specifically indicate in the context of liver function?
Liver cell damage due to conditions like hepatitis, MASLD, or drug toxicity.
Which liver enzyme is most specific for hepatocellular injury?
ALT (Alanine Aminotransferase).
What is the clinical significance of an AST:ALT ratio greater than 2?
Suggestive of alcoholic liver disease.
What is the likely diagnosis if AST:ALT ratio is less than 1 in a patient with elevated LFTs?
Metabolic Dysfuction-Associated Steatotic Liver Disease
(MASLD).
Which liver enzyme is found in both liver and other tissues like muscle and heart?
AST (Aspartate Aminotransferase).
What does isolated elevation of AST without ALT typically suggest?
A non-liver source such as muscle injury or myocardial infarction.
What does ALP elevation indicate when GGT is also elevated?
Liver or biliary tract pathology (e.g., cholestasis).
What does an elevated ALP with normal GGT usually point toward?
A non-liver source, such as bone disease.
What liver enzyme is most sensitive to alcohol use and certain medications?
GGT (Gamma-Glutamyl Transferase).
What is the function of GGT in liver function testing?
Helps determine whether an elevated ALP is of hepatic origin.
What does total bilirubin measure in liver function tests?
The sum of direct (conjugated) and indirect (unconjugated) bilirubin in the blood.
What are common causes of isolated indirect (unconjugated) hyperbilirubinemia?
Hemolysis and Gilbert’s syndrome.
What are typical causes of elevated direct (conjugated) bilirubin?
Hepatocellular dysfunction or bile duct obstruction.
What symptoms are associated with high bilirubin levels?
Jaundice, dark urine, and pale stools.
What does serum albumin level reflect in liver function tests?
The liver’s long-term synthetic function.
What conditions can cause low albumin in liver tests?
Chronic liver disease (e.g., cirrhosis), malnutrition, inflammation, and nephrotic syndrome.
Why is albumin less useful in assessing acute liver injury?
It reflects chronic changes due to its long half-life and is not sensitive to acute liver injury such as acute viral hepatitis.
What does Prothrombin Time (PT)/INR indicate in liver disease?
It indicates liver’s ability to produce clotting factors; prolonged PT/INR suggests liver synthetic failure, such as in cirrhosis or acute liver failure.
What does a prolonged PT/INR that doesn’t correct with vitamin K suggest?
Severe liver dysfunction such as fulminant hepatic failure.
Which two LFT markers best reflect decreased liver synthetic function?
Low albumin and prolonged PT/INR, commonly seen in cirrhosis or end-stage liver disease.
Which enzymes are typically elevated in hepatocellular injury pattern?
ALT and AST, particularly in hepatitis (viral, autoimmune), ischemic hepatitis, or drug-induced liver injury.
Which enzymes are typically elevated in a cholestatic pattern of liver injury?
ALP and GGT, commonly seen in bile duct obstruction, primary biliary cholangitis (PBC), or primary sclerosing cholangitis (PSC).
What combination of LFT abnormalities is commonly seen in bile duct obstruction?
Elevated ALP, GGT, and direct bilirubin, as seen in gallstones or cholangiocarcinoma.
What is a mixed pattern in liver function tests?
Elevation of both transaminases (ALT/AST) and cholestatic markers (ALP/GGT), seen in drug-induced liver injury (e.g., amoxicillin-clavulanate).
