Flashcards
LFTs
Cards in this deck (28)
- 1Liver function test panel elements:Liver function test panel:
Total bilirubin.
Direct (conjugated) bilirubin.
Alkaline phosphatase (ALP)
Gamma glutamyl transferase (GGT)
Aspartate aminotransferase (AST)
Alanine aminotransferase (ALT)
Total protein
Albumin
Globulins (by subtraction) - 2Hepatocyte injury only markers: Biliary tree injury only markers:Hepatocyte injury: AST and ALT
Biliary tree injury: ALP and GGT - 3High total bilirubin and normal conjugated bilirubin: DDx:High total bilirubin and normal conjugated bilirubin:
DDx:
Haemolysis.
Gilbert syndrome. - 4Tests for elevated unconjugated bilirubin: Start by ruling out haemolysis:Tests for elevated unconjugated bilirubin: Start by ruling out haemolysis:
Blood count
Anaemia, macrocytosis sometimes
Reticulocyte count
Haptoglobin
Binds haemoglobin and internalized by the liver
It is used up; even mild haemolysis results in very low levels
LDH (sometimes useful)
Non specific (also elevated in liver damage, MI, lymphoma and megaloblastic anaemia) - 5Chronic elevation with negative haemolysis tests:Chronic elevation with negative haemolysis tests:
Probably Gilbert syndrome
3-12% of the population
Mutation in the enzyme that contributes to conjugation of bilirubin. - 6Gilbert syndrome:Gilbert syndrome:
Polymorphism in the promoter of UGT1A1= slower conjugation.
Reduced risk for CVD and CAD
Amongst diabetics, reduced risk of retinopathy, macroalbuminuria, CAD and CVD.
Reduced mortality, less likely to be smokers and mortality lower if smoker. - 7Isolated raised ALP conditions:Isolated raised ALP:
Raised in bone building conditions;
Osteomalacia
Metastatic bone cancer
Pregnancy (placenta)
Paget’s disease
Renal osteodystrophy
Growth spurt - 8Explanation of elevated ALP and total bilirubin in a 40 year old vegan:Explanation of elevated ALP and total bilirubin in a 40 year old vegan:
ALP- reduced vitamin D intake resulting in osteomalacia.
Total bilirubin- reduced vitamin B12 intake resulting in macrocytic anaemia and intramedullary haemolysis causing an elevation in unconjugated bilirubin. - 9Explanation of elevated ALP in 64 year old man:Explanation of elevated ALP in 64 year old man:
Prostate cancer; raised PSA, reduced Hb, osteosclerotic reaction. - 10Explanation of elevated ALP in 30 year old female:Explanation of elevated ALP in 30 year old female:
Pregnancy - 11Explanation of elevated GGT:Explanation of elevated GGT:
Drugs; anticonvulsants such as phenytoin and sodium valproate.
Metabolic syndrome.
Obesity.
If the MCV is also raised; alcohol or phenytoin. - 12GGT:GGT:
Released/secreted along with ALP in biliary disease.
Can be induced by alcohol, phenytoin.
Mildly elevated in pure hepatocellular damage. - 13LFTs and alcohol:LFTs and alcohol:
At a specificity of 90%, GGT is elevated in only 44% of alcoholics.
Receiver operator characteristic curves; trade off between specificity and sensitivity depending on the cut off point. - 14Liver damage (ALP+GGT) DDx:Liver damage (ALP+GGT) DDx:
Cholestasis:
Intrahepatic:
Primary sclerosing cholangitis.
Primary biliary cirrhosis
Drugs
Extrahepatic:
Gallstones (in the instance of a stone in the common duct postcholecystectomy only 10% of patients have elevated GGT/ALP).
Pancreatic head cancer - 15Explanation for elevated total bilirubin, ALP and GGT in 85 year old male:Explanation for elevated total bilirubin, ALP and GGT in 85 year old male:
Cholestasis-2 stones in common duct + biliary sepsis. - 16Explanation for elevated ALP and GGT in 91 year old retired GP:Explanation for elevated ALP and GGT in 91 year old retired GP:
Drug induced cholestasis - 17Explanation for elevated total and direct bilirubin, ALP and GGT, AST and ALT:Explanation for elevated total and direct bilirubin, ALP and GGT, AST and ALT:
Adenocarcinoma of the head of the pancreas. - 18ALP algorithm:ALP algorithm:
Elevated ALP and Normal GGT= non hepatic; bone growth, adolescent growth, pregnancy
Both ALP and GGT elevated= biliary disease;
Obstruction
Drug-induced cholestasis
Primary sclerosing cholangitis
Primary biliary cirrhosis-autoimmune.
Pregnancy, sarcoidosis, sepsis, hepatitis etc - 19Primary sclerosing cholangitis: Primary biliary cirrhosis:Primary sclerosing cholangitis:
⅔ associated with ulcerative colitis
Multiple strictures along biliary tree.
Primary biliary cirrhosis:
Autoimmune destruction of bile ducts
Antimitochondrial antibodies can differentiate between primary sclerosing cholangitis and primary biliary cirrhosis. - 20Hepatitis DDx:Hepatitis:
Acute
Hepatitis A and B
NAFLD/steatohepatitis
EBV/CMV
Alcoholic hepatitis
haemochromatosis
Chronic - 21Non-alcoholic fatty liver disease (NAFLD):Non-alcoholic fatty liver disease (NAFLD):
Hepatic manifestation of metabolic syndrome; steatosis; fat droplets in the liver
Of the patients with raised aminotransferases, 50% have steatohepatitis (neutrophilic infiltration and inflammation)-greatest at risk of progressing to cirrhosis.
No evidence to support invasive testing for and routine liver function tests not sensitive enough and ultrasound not cost-effective. - 22Explanation for raised ALT of 8095 and INR of 3.6 in 20 year old female:Explanation for raised ALT of 8095 and INR of 3.6 in 20 year old female:
Paracetamol overdose. - 23Explanation of raised GGT, ALP, ALT, AST and bilirubin acutely in 54 year old male:Explanation of raised GGT, ALP, ALT, AST and bilirubin acutely in 54 year old male:
Hepatitis B infection. - 24EBV effect on LFTs: Raised lymphocytes DDx:EBV:
Changing pattern; every case is different.
Progress from predominantly cholestatic to hepatocellular.
Raised lymphocytes DDx: EBV/CMV or cancer - 25Raised AST only in 77 year old male: AST in non-specific to liver Heart attack; check for raised troponin.Raised AST only in 77 year old male:
AST in non-specific to liver
Heart attack; check for raised troponin. - 26Reduced albumin causes:Reduced albumin causes:
Cirrhosis (raised ALT and AST)
Nephrotic syndrome (AST raised but all other liver enzymes normal) - 27Elevated globulins DDx: Usual investigations for elevated globulins: If paraprotein is present:Elevated globulins DDx:
Plasma cell myeloma.
Infection:
Osteomyelitis
Empyema
HIV
Autoimmune- rheumatoid arthritis.
Usual investigations for elevated globulins:
Protein electrophoresis:
Polyclonal vs monoclonal
If paraprotein is present:
Blood count
Renal function
Calcium
Serum free light chains
CT/MRI
Bone marrow biopsy - 28Plasma cell myeloma detection investigations:Plasma cell myeloma:
85% have a paraprotein on electrophoresis
15% express light chains only (not obvious on electrophoresis)
99% of all myelomas show excess light chains by free light chain assay.
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- Chemical pathology Flashcards on LFTs, created by Ashutosh Kumar on 04/03/2017.
- Created by
- Ashutosh Kumar · Mar 2017
- Updated
- Mar 4, 2017
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