Abnormal LFT's

35,722 views

Published on

causes and interpreitations of abnormal liver function tests

Published in: Health & Medicine
0 Comments
34 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
35,722
On SlideShare
0
From Embeds
0
Number of Embeds
543
Actions
Shares
0
Downloads
0
Comments
0
Likes
34
Embeds 0
No embeds

No notes for slide

Abnormal LFT's

  1. 1. Abnormal LFT’s Dr E M Said
  2. 2. why do we check LFT’s? <ul><li>Well person screening </li></ul><ul><li>To investigate unexplained symptoms </li></ul><ul><li>For pre-operative or base line assessment </li></ul><ul><li>For investigation of suspected liver disease </li></ul>
  3. 3. What are LFT’s? <ul><li>The term “LFTs” is imprecise… </li></ul><ul><li>Many of the tests reflecting the health of the liver are not direct measure if its function . </li></ul><ul><li>Normal test values are arbitrarily defined as those occurring within two standard deviation of the the mean i.e 5% of of healthy individuals will have abnormal LFTs </li></ul>
  4. 4. <ul><ul><ul><ul><li>According to the American Gastroenterological Association (AGA), 1 to 4 percent of the asymptomatic population may have elevated serum liver chemistries. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>This is consistent with the usual definition . </li></ul></ul></ul></ul>
  5. 5. Remember…. <ul><li>abnormal LFTs often,but not always,indicate something wrong with the liver. </li></ul><ul><li>The commonly used LFTs may be abnormal even in a healthy liver. </li></ul><ul><li>Normal LFTs do not always mean that the liver is normal. </li></ul>
  6. 6. approach <ul><li>History: </li></ul><ul><li>The most important part in evaluation of a patient with abnormal LFTs </li></ul>
  7. 7. approach <ul><li>History: </li></ul><ul><li>The most important part in evaluation of a patient with abnormal LFTs </li></ul><ul><li>Exposure to any chemicals </li></ul><ul><li>Use of any medications </li></ul><ul><li>The duration of abnormal LFTs </li></ul><ul><li>The presence of accompanying symptoms e.g jaundice ,artheralgia,Wt loss fever,pruritus </li></ul>
  8. 8. approach <ul><li>History: </li></ul><ul><li>The most important part in evaluation of a patient with abnormal LFTs </li></ul><ul><li>Physical examination: </li></ul><ul><li>?finding suggestive CLD </li></ul>
  9. 9. approach <ul><li>History: </li></ul><ul><li>The most important part in evaluation of a patient with abnormal LFTs </li></ul><ul><li>Physical examination: </li></ul><ul><li>?finding suggestive CLD </li></ul>
  10. 10. approach <ul><li>History: </li></ul><ul><li>The most important part in evaluation of a patient with abnormal LFTs </li></ul><ul><li>Physical examination: </li></ul><ul><li>?finding suggestive CLD </li></ul><ul><li>Lap testing: </li></ul><ul><li>evaluate the overall pattern </li></ul>
  11. 11. LFT profile : <ul><li>Bilirubin </li></ul><ul><li>Total protein </li></ul><ul><li>ALT </li></ul><ul><li>ALP </li></ul><ul><li>Gamma GT </li></ul><ul><li>Albumin </li></ul><ul><li>Prothrombin time </li></ul>
  12. 12. Patterns of abnormal LFT’s <ul><li>Sole or combined elevation </li></ul><ul><li>acute or chronic </li></ul><ul><li>Predominantly Hepatocellular </li></ul><ul><li>Predominantly cholestatic </li></ul>
  13. 13. Bilirubin <ul><li>Produced by haemoglobin catabolism </li></ul><ul><li>Isolated hyper bilirubinaemia occurs in tow settings: </li></ul><ul><li>Over production </li></ul><ul><li>Impaired uptake,conjugation or excretion </li></ul>
  14. 15. ALT <ul><li>cytoplasmic enzyme that is predominantly hepatic in origin </li></ul><ul><li>Lesser quantities are found in the kidneys, heart, and skeletal muscle </li></ul><ul><li>Injury or disease of the liver parenchyma cause a release of the enzyme into the bloodstream </li></ul><ul><li>Generally, most ALT elevations are caused by liver dysfunction </li></ul>
  15. 16. Typical ALT Values in Disease
  16. 18. ALP <ul><li>Largely originate from the liver,mainly cells lining biliary ducts or membranes adjoining the bile canaliculi,and bones </li></ul><ul><li>Marked increase is typical of cholestasis (often with raised GGT) </li></ul><ul><li>Variety of bone disorders (usually without raised GGT) </li></ul><ul><li>Isoenzymes may be useful for distinguishing these sources </li></ul>
  17. 21. Gamma GT <ul><li>Found in the hepatocytes and biliary epithelial cells. </li></ul><ul><li>Sensitive in detecting hepatobiliary disease but limited by lack of specificity </li></ul><ul><li>Best used to evaluate elevation of other enzymes </li></ul><ul><li>High GGT with otherwise normal liver should not lead to exhaustive work up for liver disease </li></ul>
  18. 22. Gamma GT <ul><li>Found in the hepatocytes and biliary epithelial cells. </li></ul><ul><li>Sensitive in detecting hepatobiliary disease but limited by lack of specificity </li></ul><ul><li>Best used to evaluate elevation of other enzymes </li></ul><ul><li>High GGT with otherwise normal liver should not lead to exhaustive work up for liver disease </li></ul>Twofold elevation with AST:ALT ratio2:1suggest alcohol abuse
  19. 24. Albumin <ul><li>Albumin is synthesised in the liver </li></ul><ul><li>Albumin has a plasma half-life of three weeks; therefore, serum albumin concentrations change slowly in response to alterations in synthesis. </li></ul><ul><li>In practice, patients with low serum albumin concentrations and no other LFT abnormalities are likely to have a nonhepatic cause for low albumin, such as proteinuria or an acute or chronic inflammatory state. </li></ul>
  20. 25. Prothrombin time <ul><li>Not usually included in the LFTs panel </li></ul><ul><li>abnormal PT prolongation may be a sign of serious liver dysfunction. </li></ul><ul><li>An elevated PT can result from a vitamin K deficiency ,a trial of vitamin K injections is the most practical way to exclude vitamin K deficiency in such patients. </li></ul>
  21. 26. Predominantly Hepatocellular <ul><li>Usually ALT>ALP </li></ul><ul><li>Alcoholic hepatitis </li></ul>
  22. 27. Predominantly Hepatocellular <ul><li>Usually ALT>ALP </li></ul><ul><li>Alcoholic hepatitis </li></ul><ul><li>Typically AST:ALT is 2:1 </li></ul><ul><li>AST rarely exceed300 </li></ul>
  23. 28. Predominantly Hepatocellular <ul><li>Usually ALT>ALP </li></ul><ul><li>Alcoholic hepatitis </li></ul><ul><li>Viral hepatitis </li></ul>
  24. 29. Predominantly Hepatocellular <ul><li>Usually ALT>ALP </li></ul><ul><li>Alcoholic hepatitis </li></ul><ul><li>Viral hepatitis </li></ul>Aminotransferase>500 ALT greater or equal AST
  25. 30. Predominantly Hepatocellular <ul><li>Usually ALT>ALP </li></ul><ul><li>Alcoholic hepatitis </li></ul><ul><li>Viral hepatitis </li></ul><ul><li>Toxic hepatitis </li></ul><ul><li>Shock liver(ischemic hepatitis) </li></ul>
  26. 31. Predominantly Hepatocellular <ul><li>Usually ALT>ALP </li></ul><ul><li>Alcoholic hepatitis </li></ul><ul><li>Viral hepatitis </li></ul><ul><li>Toxic hepatitis </li></ul><ul><li>Shock liver(ischemic hepatitis) </li></ul>exceeding1000IU/L Or 50x upper limit of normal
  27. 32. Predominantly Hepatocellular <ul><li>Usually ALT>ALP </li></ul><ul><li>Alcoholic hepatitis </li></ul><ul><li>Viral hepatitis </li></ul><ul><li>Toxic hepatitis </li></ul><ul><li>Shock liver(ischemic hepatitis) </li></ul><ul><li>Wilson disease </li></ul><ul><li>Autoimmune hepatitis </li></ul>
  28. 33. Copyright ©2003 BMJ Publishing Group Ltd. Limdi, J K et al. Postgrad Med J 2003;79:307-312 Suggested algorithm for evaluating raised transaminases
  29. 34. Predominantly cholestatic <ul><li>Usually ALP>ALT </li></ul><ul><li>1 st determine intra or extrahepatic </li></ul><ul><li>Distinction may not be straightforward </li></ul><ul><li>1 st step is Ultrasound </li></ul><ul><li>biliary dilatation extrahepatic cholestasis </li></ul><ul><li>no dilatation intrahepatic cholestasis </li></ul><ul><li>False negative in partial obstruction,cirrhosis or PSC </li></ul>
  30. 35. extrahepatic cholestasis <ul><li>Choledocholithiasis </li></ul><ul><li>Malignant causes: </li></ul><ul><li>Pancreatic,gall bladder,ampullary and cholangiocarcinoma </li></ul><ul><li>Hilar lymphadenopathy </li></ul><ul><li>Chronic pancreatitis </li></ul><ul><li>AIDS cholangiopathy </li></ul>
  31. 36. intrahepatic cholestasis <ul><li>Drug induced </li></ul><ul><li>Primary biliary cirrhosis </li></ul><ul><li>Primary sclerosing cholangitis </li></ul><ul><li>Other causes include: </li></ul><ul><li>Sepsis,postoperative,paraneoplastic, </li></ul><ul><li>thyroid cancer,Hypernephroma & prostate cancer </li></ul>
  32. 37. Copyright ©2003 BMJ Publishing Group Ltd. Limdi, J K et al. Postgrad Med J 2003;79:307-312 Suggested algorithm for evaluating a raised ALP
  33. 38. The role of liver biopsy <ul><li>Most patients with abnormal LFTs with suspected etiologic factors for liver disease are identified by history taking, physical examination, further blood tests, and imaging </li></ul><ul><li>In patients with unexplained LFTs elevations, a liver biopsy may be helpful to identify the cause of liver disease </li></ul><ul><li>The decision to perform a liver biopsy must balance the possible risks of the procedure (eg, discomfort, bleeding, peritonitis, pneumothorax) with the potential benefits </li></ul>

×