Liver Function Test s

1. Liver Function Tests รองศาสตราจารย์แพทย์หญิงพรรธนมณฑน์ อุชชิน ภาควิชาเวชศาสตร์ชันสูตร คณะแพทยศาสตร์ จุฬาลงกรณ์มหาวิทยาลัย

2. วัตถุประสงค์ : หลังจากเสร็จสิ้นการเรียน นิสิตสามารถ 1. อธิบายลักษณะทั่วไปของตับ 2. เข้าใจหน้าที่สำคัญของตับ(Major Functions of the Liver) 3. แยกชนิดและอธิบายการเกิด Jaundice ชนิดต่างๆ ในร่างกาย 4. เข้าใจ Pathway of Bilirubin 5. รู้จักInherited Disorders of Bilirubin Metabolism 6. รู้จักชนิดต่างๆของ LFTs 7. เข้าใจหลักการและแปลผล routine LFTs ที่เลือกได้ 8. อธิบายสาเหตุและเลือกใช้ LFTs ที่เหมาะสมสำหรับโรคตับและทางเดินน้ำดีที่พบบ่อยๆได้ 9. แปลผล LFTs ที่เลือกใช้ได้

3. LIVER Blood supply 15ml/min: Portal vein, Hepatic artery Parenchymal cells : Hepatocyte Nonparenchymal cells : Endothelial cells Kupffer cells Hepatic stellate cells Pit cells Hypoglycemia

5. Major Functions of the Liver Synthesis and metabolism of proteins,carbohydrates and lipids Production, metabolism and excretion of bile Detoxification and drug metabolism Enzymes synthesis Storage of vitamins and minerals Biotransformation or Inactivation of hormones Phagocytosis

6. Synthesis & metabolism of proteins,carbohydrates and fats 90 % of plasma protein ( except forgammaglobulin, hemoglobin ) nutrition, oncotic pressure, transportation glycogenesis, glycogenolysis, glycolysis, gluconeogenesis triglycerides, VLDL, LDL, HDL, cholesterol

7. Production, metabolism and excretion of bile น้ำดี : bilirubin, bile acids / salts, electrolytes, cholesterol, fatty acids, น้ำ, lecithin primary bile acids : cholic, chenodeoxycholic acids secondary bile acids : deoxycholic, lithocholic acids enterohepatic circulation bilirubin : hemoglobin, myoglobin, cytochromes, catalase unconjugated bilirubin ( + albumin )

8. Production, metabolism and excretion of bile Protein Y & Z , Ligandin UDPG - T ( Uridyldiphosphate glucuronyl transferase ) conjugated bilirubin ( + glucuronic acids ) urobilinogen, stercobilin biliprotein ( delta bilirubin ) jaundice / icteric ( TB > 2.5 mg /dl )

10. Jaundice classified by origin Prehepatic ( TB < 5 mg/dl) : Hereditary hemolytic processes Acquired hemolytic processes Ineffective erythropoiesis Impaired delivery of bilirubin to the liver Sport injuries

11. Jaundice classified by origin 2. Hepatic: Pre - microsomal Microsomal Post - microsomal Intrahepatic obstruction 3. Posthepatic : CBD stones Cancers of the bile ducts, pancreas Stricture, stenosis, atresia Cholagitis, Choledochal cysts

12. Physiological classification of Jaundice 1. Unconjugated Hyperbilirubinemia Production Delivery to hepatocyte Uptake across hepatocytic membrane Storage in cytosol Conjugation

13. Physiological classification of Jaundice 2. Conjugated Hyperbilirubinemia Secretion into canaliculi Drainage Intrahepatic obstruction Septicemia, total parenteral nutrition Drugs

14. Inherited Disorder of Bilirubin Metabolism Gilbert’s syndrome : mild fluccuate unconjugated hyperbilirubinemia conjugation +/- uptake normal lifespan Crigler - Najjar syndrome : severe unconjugated hyperbilirubinemia Type I : absence of UDPG - T Type II : partial defect of UDPG - T

15. Inherited Disorder of Bilirubin Metabolism Dubin - Johnson syndrome : mild fluccuate conjugated hyperbilirubinemia hepatic excretion normal lifespan hepatic pigmentation, bilirubinuria Rotor syndrome : unknown defect similar to Dubin - Johnson syndrome no hepatic pigmentation

16. Detoxification and Drug Metabolism Phase I : oxidation, hydroxylation Phase II : conjugation with glucuronic acid, glycine, taurine and sulfate Cytochrome P450 and allied hepatic enzyme system Epoxide hydrolase UDP - glucuronosyl transferase Sulphotransferase Glutathione S - transferase

17. Enzymes Synthesis Cytoplasmic enzyme : AST(SGOT), ALT(SGPT), LD Mitochondrial enzyme : AST Canalicular enzyme : ALP, GGT

18. Storage of Vitamins and Minerals Fat soluble vitamins ( A, D, E, K ) Vitamin B12 Iron Copper

19. Biotransformation or inactivation of hormones Somatomedin Glucagon

20. Phagocytosis Kupffer cells Pit cells

21. LIVER FUNCTION TESTS 1. Routine ( Conventional ) LFTs bilirubin, urobilinogen, ALP, AST, ALT, GGT 2. True tests of liver function ( QLFTs : Quantitative LFTs ) Dynamic test ; measure metabolite / excretion rate, liver blood flow or functional hepatic mass

22. QLFTs Metabolic Capacity : Indocyanine Green ( ICG ) test 14C- Galactose breath test Microsomal enzyme function : Aminopurine breath test Caffeine breath test Functional hepatic perfusion : Galactose tolerance test ICG ( low dose ) test Microsomal enzyme function and hepatic perfusion : Lidocaine clearance test

23. LIVER FUNCTION TESTS 3. Provide information about severity and prognosis TP, Alb, Clotting factors, Ammonia 4. Special laboratory tests Alpha-1-antitrypsin, Alpha-fetoprotein, Autoantibodies Ceruloplasmin, Copper, Hepatitis markers Immunoglobulin, Iron and ferritin, Glutamine, LD

24. Serum Bilirubin Newborn (Direct spectrophotometric method) > 1month (Colorimetric Wahlefeld method)

25. Urobilinogen in urine & feces Urinary urobilinogen Hemolytic disease Viral hepatitis Fecal urobilinogen Biliary obstruction Hepatocellular disease

26. LIVER ENZYMES Principles of Diagnostic Enzymology Half - life of liver enzymes in serum ALP ………..3 - 7 วัน ALT……….. 50ชั่วโมง AST…………12 - 14 ชั่วโมง GGT………..7 - 10วัน

27. Factors affecting enzyme levels in serum 1. Leakage of enzymes from cells Hypoxia, Chemicals and drugs, Physical agents, Microbiological agents, Immune mechanisms, Genetic defects, Nutritional disorders 2. Altered enzyme production 3. Clearance of enzymes average half - life in serum 6-48 ชั่วโมง

28. Characteristics of Elevated Concentration Mild : AST, ALT, GGT < 2 - 3x URL ALP < 1.5 - 2 x URL Moderate : AST, ALT up to 20 x URL GGT up to 10 x URL ALP up to 5 x URL Marked : AST, ALT > 20 x URL GGT > 10 x URL ALP > 5 x URL

29. AST &ALT Mild : Fatty liver NASH ( Nonalcoholic steatohepatitis ) Chronic viral hepatitis Marked : Acute viral hepatitis Drug or Toxin induced hepatic necrosis Ischemic hepatitis

30. AST &ALT > 2 : Alcoholic liver disease > 1 : Cirrhosis < 1 : NASH Viral hepatitis

31. Aspartate Transaminase (AST,SGOT) UV assay : Pyridoxal phosphate Tissue Sources : cardiac tissue, liver, skeletal muscle, kidney, pancreas, RBC Sources of Error: hemolysis Diagnostic Significances: Cardiac disease, Hepatobiliary disease, Major crush injuries, Skeletal muscle disease, Pancreatitis, Delerium tremens. Pregnancy

32. Alanine Transaminase ( ALT,SGPT ) UV assay : Pyridoxal phosphate Tissue Sources :liver Sources of Error :hemolysis Diagnostic Significances : Hepatobiliary disease, Heart failure with hepatic necrosis

33. Alkaline Phosphatase ( ALP ) ALP >3 x URL Hepatobiliary disease ( cholestasis ) Marked increase Extrahepatic biliary obstruction PBC ( Primary Biliary Cirrhosis ) PSC ( Primary Sclerosing Cholangitis ) Drug - induced cholestasis Mild - moderate increase Amyloidosis Granulomatous disease Neoplasms, Hodgkin’s disease Renal cell carcinoma

34. Alkaline Phosphatase ( ALP ) Colorimetric assay : ++Mg Tissue Sources: intestinal epithelium, liver (sinusoidal and bile canalicular membrane), bone (osteoblast), kidney tubules, placenta, spleen Sources of Error: phosphate, borate, oxalate, cyanide, L-phenylalanine, urea, hemolysis Diagnostic Significances: Hepatobiliary disease, Bone disease, Healing fracture, Normal growth,Pregnancy Hereditary hypophosphatasia

35. Alkaline Phosphatase ( ALP ) Diagnostic Significances Isoenzymes ; liver(heat stable), bone(heat labile), intestinal and placental Placenta-like ( Regan & Nagao ) ; germ cell tumors, seminoma, serous carcinoma of ovary, endometrial carcinoma and leukemia

36. - Glutamyl Transferase ( GGT ) Enzymatic Colorimetric assay Tissue sources : cell membrane and mitochondria Sources of Error : smoking, pregnancy, alcohol, phenytoin, barbiturate, carbamazepine, valproic acid,oral contraceptive

37. - Glutamyl Transferase ( GGT ) Diagnostic Significances : Hepatobiliary disease, Hepatic microsomal enzyme induction ( drugs ; warfarin, phenytoin, phenobarbital ), Alcoholism and heavy drinking, Pancreatitis, Diabetic mellitus, Congestive cardiac failure

38. Lactate Dehydrogenase ( LD, LDH ) UV assay Tissue Sources : myocardium, kidney, liver, skeletal muscle and RBC Sources of Error : hemolysis Diagnostic Significances : AMI, Hepatobiliary disease,Renal disease, Cancers, Anemia, Progressive muscular dystrophy, Isoenzymes( LD1,2,3,4,5 )

39. Liver Enzymes Routine AST, ALT, ALP Liver specific OCT (Ornithine Carbamoyl Transferase) ID (Iditol Dehydrogenase), Guanase hepatic isoenzyme of ALP

40. Liver Enzymes Interpretation AST&ALT ………..hepatocellular damage ALP…………………cholestasis

41. Plasma Proteins Colorimetric assay Hyperproteinemia :Dehydration, Liver diseases, Chronic inflammatory diseases, Increased plasma immunoglobulins, Faulty technique in blood sample Hypoproteinemia :Overhydration, Pregnancy, Malnutrition, Liver diseases, Protein loss, Hypogammaglobulinemia, Hyperthyroidism

42. Albumin Colorimetric assay :Dye-binding method Sources of Error :hemolysis Hypoalbuminemia :Hereditary defects, Malnutrition, Malabsorptive disease, Severe burn, Shock, Chronic liver disease, Major surgery, Accidental trauma, Infection, Renal disease, Exfoliative dermatitis Protein-losing gastroenteropathy,

43. Clotting Factors Quick’s One Stage Prothrombin Time or Plasma Prothrombin Time Extrinsic pathway Factors : I, II, V, VII, X INR ( International Normalized Ratio )

44. Ammonia Enzymatic kinetic assay EDTA plasma, hemolysis, protein in food, drugs, exercise Diagnostic Significances ;Reye’s syndrome, Liver disease, Cirrhosis, Hepatic coma, Hyperornithinemia Unexplained lethargy and vomiting, Encephalitis & Neonate with unexplained neurologic deterioration

45. Ceruloplasmin(CERU; Cp ) Ferrioxidase activity, acute phase protein Immunoturbidimetric method Serum, heparinized plasma, hemolysis, lipemia & rheumatic factors Diagnostic Significances ;Wilson’s disease, Monkes disease, Nutritional copper deficiency, Renal copper loss, Massive burn, Inflammation disease, RE neoplasia, Biliary obstruction, Estrogen therapy, Pregnancy

46. Most Common Disease of Liver 1. Hepatitis : Acute ( viruses, toxins and drugs ) recovery from viral hepatitis ...transaminases are normal within 10-12 weeks ( > 6 months ………chronic ) Chronic ( autoimmune, viruses, alcohol and drugs ) : normal ALP,increased AST&ALTabnormalAlbumin & PT

47. Most Common Disease of Liver 2. Cirrhosis : Chronic excessive alcohol intake Autoimmune chronic active hepatitis Chronic hepatitis B, C, D, Inherited metabolic disease : Wilson’s disease, DM, Glycogen storage disease, Galactosemia Disease of Prolonged Cholestasis : PBC, PSC, Cystic fibrosis, Biliary atresia *decompensated cirrhosis…increased blood ammonia

48. Most Common Disease of Liver 3. Tumours Metastatic : primary sites ; lung, bronchus, breast, gastrointestinal tract, prostate gland *normal TB, AST, mild increases of GGT and ALP with marked increase of LD Hepatoma : Cirrhosis, Hepatitis B, C, Aflatoxins *increases of alpha-fetoprotein and ALP

49. Differential of Hepatocellular Injury and Cholestasis

50. Pattern of Cholestasis Bilirubinostasis………… Hepatocyte Cholestatic hepatitis……Canalicular Ductular injury……………Intrahepatic bile ducts Complete obstruction… Extrahepatic bile ducts