Investigations of Liver Diseases PDF

 Investigations of Liver Diseases Dr Ahmed Alyan Abdelaziz Director of Emergency and Trauma University Hospital,Qena Faculty of Medicine, SVU Lecturer of Tropical Medicine and Gastroenterology ,SVU Liver Function Tests (LFT...

 Investigations of Liver Diseases Dr Ahmed Alyan Abdelaziz Director of Emergency and Trauma University Hospital,Qena Faculty of Medicine, SVU Lecturer of Tropical Medicine and Gastroenterology ,SVU Liver Function Tests (LFT) Value: 1- Confirming that the liver is diseased, 2- Determine the severity of the disease, 3- Follow up the course of the disease, 4- Differentiate between hepatocellular versus obstructive ;It includes the following  Tests that reflect hepatobiliary injury  Tests that measure hepatic synthetic function  Tests that measure hepatic capacity of clearance and organic anion transport  Tests that measure hepatic metabolic function  Tests for accurate etiological diagnosis Firstly, tests that reflect hepatobiliary injury Aminotransferase enzymes (AST /ALT).1 Hepatic ALP.2 Gamma GT.3 lactate dehydrogenase LDH.4 Leucine aminopeptidase (LAP).5 nucleotidase (5’ NT) ’5.6 1-Serum transaminases:  Glutamic pyruvic transaminase GPT (synonym is alanine transaminase ALT)  Glutamic oxaloacetic transaminase, GOT (synonym is aspartate transaminase AST).  Both indicate necrosis of the hepatocytes. Increased in acute hepatitis, chronic hepatitis, cirrhosis, cholangitis and acute circulatory failure.  Normal range of ALT is 5-35 IU/L and AST is 5- 40 IU/L.  ALT is more specific.  These enzymes are also present in heart, liver, kidneys and muscles. Aminotransferase enzymes  AST/ALT ratio (De-Ritis ratio) o Necrotizing o Inflammatory type where the ratio less than or equal 1 and this occur with most of liver diseases without cirrhosis except alcoholic diseases type where the ratio more than 1 where there is release of the mitochondrial AST;  More than 1 with when cirrhosis occurs  More than 2 with alcoholic liver diseases  More than 4 with fulminant hepatitis particulary with paracetamol CAF toxicity Hepatic ALP.2  Mainly released from the liver but other tissues contain it, such as bone, placenta, kidney, and ileum but more than 80% of serum ALP is released from bone and liver.  It is level is age, sex, weight, height & smoking dependent. ALPone  Hepatic causes of increased ALP;  Less than three folds  Can occur with multiple parenchymal liver diseases  Between 3- 10 folds  Cholestasis  Infiltrative mass or lesions as tumors and granulomata  More than 10 folds  Vanishing bile duct syndrome  Cholangitis  Malignant complete extrahepatic obstruction  Raised ALP with normal bilirubin  Early PBC  Localized biliary obstruction Gamma glutamyl transpeptidase.3  - Not organ specific but released from many organs as liver, kidney but not from bone. ‫الجامعة الكندية‬  - Most sensitive indicator for biliary tract diseases where it correlates well with ALP but its poor sensitivity makes it less valuable than 5’NU  - Certain type of it can be used as screening for HCC Nucleo-peptidase’5.4  Specific for biliary diseases but not ordinary requested due to high cost Lactate dehydrogenase.5  - Of no diagnostic value but the level is increased in the following; o Shock liver o Hemolysis with liver diseases  - ALT / LDH ratio o More than 1.5 occurs with acute viral hepatitis o Less than 1.5 occurs with acetaminophen toxicity and shock liver Secondary, Tests that measure hepatic synthetic function  Mainly include the followings proteins; o Coagulation factors and anti-coagulant o Albumin o Lipoproteins Coagulation factors and anti-coagulant  All coagulation factors are produced by the liver except factor VIII  Production of factors II,VII,VIII and X are produced in presence of vit K  All of them have short T-half and can be used as parameters of liver function  Anti-coagulant factors, Liver can produce the following, protein C, S and antithrombin III. Tests for the coagulation and anti- coagulant factors Prothrombin time (PT):  It depends on factors II (prothrombin), VII and X of liver origin.  It is a sensitive test for coagulation defects in hepatic and biliary disease.  Prolonged PT (normal 11-13 seconds) occurs with both hepatocellular and obstructive jaundice.  This is corrected after 10 mg vitamin K injection in case of obstructive jaundice. It is a sensitive indicator of hepatocellular necrosis and/or prognosis Plasma proteins: a- Albumin:  It is synthesized solely by the liver. It is low in chronic liver diseases.  Low concentration is a bad sign.  Normal level is 3.5-5.0 gm. b- Globulins:  increased in chronic liver disease with reduction in albumin:globulin ratio 2:1.  IgG is increased in chronic active hepatitis,  IgA in alcoholic liver disease and IgM in primary biliary cirrhosis Thirdly, Tests that measure hepatic capacity of clearance and organic anion transport Serum bile acids  There are two types of it;  Primary that formed in the liver only include cholic, chenodeoxycholic and ursodeoxycholic acid  Secondary that result from the action of intestinal bacteria on the primary bile acids include deoxycholic acids and lithocholic acids. Serum bilirubin: Normal range 0.3-1.0 mg/dL (5-17 µmol).  Its estimation in serum is based on Van den Berg diazo reaction.  70% of it is non-conjugated and 30% is conjugated.  Both fractions rise in hepatocellular jaundice  conjugated bilirubin rises in obstructive jaundice  unconjugated bilirubin rises in hemolytic jaundice. Bilirubin in urine Normally, there is no bilirubin in urine. It is present in obstructive (cholestatic) and hepatocellular jaundice. Urobilinogen in urine: It is increased in hemolytic jaundice and is absent in obstructive jaundice. Fourthly, test the clearance function of the liver  Aim to measure levels or rates of clearance chemically or using radiolabeled tracers:  Examples; 1) Serum ammonia level ‫نه بتشرب قهوة قطن نضيفه‬ 2) Blood ketone level 3) Caffeine level in saliva Fifthly; tests to diagnose the etiology  Tests of Viral or toxic liver disease Viral Antigen or Antibodies (HCV, HBV, HEV, HAV, CMV, EBV)  Auto-antibodies in autoimmune diseases AMA in PBC ANA, ALKM in AIH.  Tests for metabolic diseases Wilson’s disease: ceruloplasmin level decreases Haemochromatosis: transferrin level 90% saturated (N.30%) Alpha 1 antitrypsin deficiency: alpha 1 antitrypsin decrease  Electrophoretic pattern of serum proteins IgA rise in Alcoholic cirrhosis IgM rise in PBC. IgG rise in chronic and autoimmune hepatitis. Others  Alpha fetoprotein : raised in hepatocellular carcinoma, early infancy, chronic hepatitis and cirrhosis. Liver Biopsy  It is a relatively safe procedure in experienced hands.  It is carried out with Tru-Cut needle using local analgesia.  Theprothrombin time should not be prolonged to 3 seconds more than the control. The platelet count should exceed 80,000/cmm. Indications: 1- Chronic liver disease, especially chronic active hepatitis, liver cirrhosis and alcoholic liver disease. 2- Cholestatic jaundice after exclusion of extrahepatic obstruction. 3- Unexplained hepatomegaly. 4- Persistently abnormal liver function tests. 5- Suspected hepatic tumor, infiltrative diseases of the liver or space-occupying lesions. Contraindications: 1- Prolonged prothrombin time, thrombocytopenia and coagulation disorders. 2- Uncooperative patient, tense ascites and right sided empyema. 3- Hydatid disease of the liver. Complications: - Bleeding (this is rare): may be fatal. - Pleurisy and perihepatitis. - Intrahepatic hematomas and arteriovenous fistula. - Biliary peritonitis, infection and puncture of other organs.  ‫االسئلة اللي ممكن تيجي‬ ‫وده اللي ممكن ييجي ريتن باقي المحاضره اختار) ‪opsy‬‬ ‫) ‪-dependent factors (2 7 9 10‬‬ ‫)‪mal albumin (3.5-5 gm‬‬ ‫)‪mal PT (11-13 sec‬‬ ‫فيها ‪ALT‬اكت‬ ‫الحاجات اللي بيعلي‬ ‫‪AST‬‬ ‫‪( CAF‬‬ THANK YOU