Abnormal Liver Enzymes Year 4 Internal Medicine Notes

Abnormal Liver Enzymes Year 4 · Internal Medicine Collection: 4TH YEAR ALL NOTES / IMED / I MED BEAUTIFUL NOTES / GIT -- ● Objectives: ● Approach to liver enzymes ● Selected disease\n[ Color index: ​Important​ ​Notes ​ ​Extra​ ]\n[​ ​Editing file​ ​ ​ ​Feedback​ ​ ​Share your notes​ ​ ​Shared notes​ ​ ​Twitter​ ] ● Resources: ● 435 slides\n\n★ This lecture was made based on last year’s slides and objectives (LFT and ​jaundice​),\nunfortunately the doctor decided to change the content and added some ​selective diseases\n(Most of them are mentioned in Liver Cirrhosis lecture) rather than jaundice and due to\nthe ​short notice​ we couldn’t cover all of them. ★ We tried to cover the approach to LFT and its interpretation much as we could, and we\nmade sure that all the ​diagnostic tests ​for the selected diseases are mentioned in this file.\n\n● Done by:​ ​Abdulrahman AlZamil & ​Fahad AlAbdullatif ● Team sub-leader:​ ​Jwaher Alharbi ● Team leaders:​ ​Khawla AlAmmari & Fahad AlAbdullatif ● Revised by: ​Ahmad Alyahya \n\n Abnormal liver enzymes Routine blood sample sent to the laboratory for liver biochemistry to measure serum levels of bilirubin, ​aminotransferase (AST/ALT)​, ​alkaline phosphatase (ALP)​, g ​ amma-glutamyl (GGT) transpeptidase and total proteins. These tests are often referred to as liver function tests but this term is misleading as they don’t accurately reflect how well the liver is functioning. These tests are best referred to as liver blood tests. Liver synthetic function is determined by measuring the prothrombin time and serum albumin.\n● When you see abnormal liver enzymes you should think first of the possible cause?\nthe pathology could be either due to:\n1-Hepatocellular disease 2- Cholestatic disease 3-Mixed\n● ALT & AST are hepatocellular enzymes\n● ALK-P & GGT represent obstructive or (Cholestatic) disease\n● The AST & ALT and ALK-P test are most useful to make the distinction between\nhepatocellular and cholestatic diseases\n● If you see ALT & AST elevated out of proportion (Extremly) compared to ALK-P →\nHepatocellular disease\n● Upper limit of normal serum ALT (​30​ IU/L), ALK (​130​ IU/L)\n● Example (1): ALT & AST =200 (ALT & AST levels greater than 7 times the upper limit of\nnormal) ALK-P 200 ( increased approximately 1 time ) so what is the cause? ​a\nHepatocellular cause\n● Example (2): ALK-P =( 500 ) ALT= (60) AST= (70)? ​a Cholestatic cause Sometimes it can be mixed, so don't get confused go back and see the clinical scenario and the you can decide\n\n Liver Function Tests\n\n Liver disease is under one of the following category:\n1. Hepatocellular​ injury with predominant increase in AST and ALT +/- increase in alkaline\nphosphatase and Direct bilirubin (due to injury in duct system) Indirect bilirubin1\n2. Obstruction​ with predominant increase in Alkaline phosphatase and direct bilirubin +/- increase\nin AST and ALT\n3. Jaundice​ (pre-hepatic, Intra-hepatic and post-hepatic)\n4. Infiltrative diseases​ with predominant increase in Alkaline phosphatase +/- Direct bilirubin\n\n1 May increase in advanced liver disease \n\n ● Here’s a list of some of the common causes of liver diseases and\nabnormal liver enzymes:\ngo through them before we talk about the interpretation of the specific tests.\n\n ​ Hepatocellular causes ​Cholestatic causes ● Viral hepatitis (Acute or chronic) A- Extrahepatic = obstructive ● Non-alcoholic steatohepatitis ● Biliary stone\n(​NASH​) and alcoholic\nsteatohepatitis (​ASH​) ● Stricture: ​Malignant: Peri-ampullary\ntumors2, Primary Scleroaing Cholangitis,\nAIDs cholangiopathy ● Drugs eg. Tylenol OD, idiosyncratic\nreaction B-Intra-hepatic = non-obstructive ● Vascular injury: ​such as in PBC/ PSC (small duct) / cystic fibrosis\nhypotension, vascular outflow\nobstruction ● Autoimmune Hepatitis / ​Primary Sepsis, Total parenteral nutrition, Drugs\nbiliary cirrhosis/celiac \nInfiltrative​:\n● Granulomatous diseases ​such as TB, ● Metabolic disease sarcoidosis, lymphoma\n● Amyloidosis ● Passed stone intrahepatic cholestasis of pregnancy ● Pregnancy related Some Hepatocellular causes\n\n ★ PBC3 is a ​cholestatic disease​, yet we can see some increase in hepatocellular\nenzymes because of some degree of periportal and lobular necrosis.\n\n 2\nPancreatic carcinoma in the head of pancreas\n3\nPrimary biliary cholangitis (primary liver cirrhosis) \n\n★ Follow the mind-map below to learn how to approach patients with suspected\nliver disease: ​IMPORTANT\n\n★ Another form of the previous mind map:\n\n● MRCP​ = Magnetic resonance cholangiopancreatography ● EUS​ = Endoscopic Ultrasound ● ERCP​ = Endoscopic retrograde cholangiopancreatography \n\n Liver function tests (LFTs)\n\n ● AMINOTRANSFERASES (AST/ALT): These enzymes (often referred to as transaminases) are contained in hepatocytes and leak into the blood with liver cell damage.\n➔ Aspartate aminotransferase (AST) is primarily a mitochondrial enzyme (80%;\n20% in cytoplasm) and is also present in heart, musc