LAB DIAGNOSIS OF LIVER DISEASES

Clinical Manifestations of Liver Dysfunction

• Jaundice
• Portal Hypertension
• Bleeding oesophageal varices
• Ascites
• Spontaneous bacterial peritonitis
• Hepatic encephalopathy
• Hepatorenal syndrome
• Disordered haemostasis in liver diseases- e.g.-dysfibrinogenemia, thrombocytopenia

I.Serum Bilirubin 

• Serial measurement of bilirubin helps assess the severity of liver damage in several types of liver disease (e.g., alcoholic hepatitis, cirrhosis).
• In acute hepatitis, bilirubin peaks later than enzymes do, and serum bilirubin remains elevated for longer than urine bilirubin because of the presence of biliprotein (δ-bilirubin).
• In most liver diseases there is an increase in conjugated bilirubin whereas increases in unconjugated bilirubin mostly are due to causes other than liver diseases

II.Serum Albumin

• Serum albumin measurements are useful in assessing the chronicity of the disease.

• The serum albumin concentration is decreased in

1.     Severe acute liver disease

2.     Inflammatory disorders

3.     Malnutrition

4.     Nephrotic syndrome

·   III.Plasma Enzymes

• They allow differentiation of hepatocellular disease from the cholestatic disease.
• SGOT,SGPT - markers of hepatocellular injury
• GGT,ALP - markers of cholestasis

IV.Prothrombin Time(PT)

• Serial PT measurements are used to determine synthetic liver function
• PT is the most important prognostic marker in acute liver disease 
• Serial PT measurements can be used to differentiate between cholestasis and severe hepatocellular disease.
• Cholestasis will cause a decrease in PT as the result of malabsorption of vitamin K.
• After vitamin K injection, in practice, PT should be measured again If the PT corrects after vitamin k replacement, the patient has cholestasis, If the PT does not return to normal, the patient has the severe hepatocellular disease