LFTs / liver biochemistry Flashcards
what are ‘true’ liver function tests that reflect the synthetic function of the liver ?
albumin
PT - prothrombin time
bilirubin
what are transaminases
AST/ALT - they are intracellular hepatic enzymes which convert aspartate and alanine into ketoglutarate
what are markers of liver biochemistry and what do they show
AST/ALT
ALP
GGT
- they give a clue to underlying liver pathology and should be validated by clinical findings and investigations
if AST/ALT is higher than ALP - what does this suggest ?
hepatitis
if ALP is more elevated than AST/ALT wha does this suggest ?
obstruction
what does an acute rise in GGT suggest
alcohol consumption
what is the function of alkaline phosphatase
ALP - catalyses the hydrolysis of phosphate esters
what is pre hepatic jaundice, and its findings
> due to excess heme production as a result if haemolysis
have raised total bilirubin, normal conjugated bilirubin, raised unconjugated bilirubin, normal LFTs, normal urine and stool colour
what is intra hepatic jaundice, and its findings
> hepatocellular damage leading to intrahepatic cholestasis
>caused by hepatitis, drugs, cirrhosis, pregnancy
raised total bilirubin, raised both unconjugated and conjugated bilirubin, hepatic LFTs, dark and pale urine/stool
what is post hepatic jaundice, and its findings
> obstruction to bile outflow from the liver (ie it leaks into blood)
>causes include gallstones, cholangiocarcinoma, head of pancreas cancer, biliary structure, PSC, PBC
raised total bilirubin, raised conjugated bilirubin, normal unconjugated bilirubin and obstructive LFTs, dark urine and pale stools
what are the clinical signs of jaundice and what are they due to ?
yellowing of the sclera/skin, itch, dark urine, pale stools (signs of liver disease)
due to hyperbilirubineamia (>40 mmol/L)
viral hepatitis - acute
-what are the clinical features
nausea/vomitting, diarrhoea, flu like symptoms, hepatosplenomegaly - rarely becomes fulminant hepatitis; encephalopathy, coagulopathy, jaundice, ascites, raised AST/ALTs and slight elevation of ALPs
viral hepatitis - acute
-characteristics
Hep A –> RNA virus transmitted by faeco-oral route
>has a short incubation period and does not cause chronic disease
viral hepatitis - acute
-treatment
support and vaccination
viral hepatitis:
Hep D
is an incomplete RNA virus needing concomitant HepB infection in order to complete its life cycle
Tx - interferon
