Clinical Nutrition

Lesson 17: Diseases of the liver

Diagnosis

Liver function test: For biochemical and clinical evaluation of the status of liver function, a special set of laboratory tests are conducted on blood and urine of the patient and are called liver function tests. These include the following.

In blood

1. Total and conjugated serum bilirubin test (conjugated bilirubin glucuronide)
2. Serum gluatamic transaminase test (SGOT)
3. Serum glutamic pyruvic transaminase test(SGPT)
4. Serum alkaline phosphatase test
5. Serum total protein test
6. Serum albumin test
7. Serum globulin test
8. Serum albumin-globulin ratio
9. Serum cholesterol
10. Flocculation tests- These tests are performed by adding serum to reagents such as thymol, zinc sulphate and cephalin –cholesterol. Albumin will retard the precipitation or turgidity when these reagents are added whereas globulin will tend to cause precipitation.
11. Carbohydrate tolerance test: Glucose, galactose and glucagon tolerance tests are abnormal. In liver dysfunction, glycogen storage is impaired and the administration of glucagon leads to hypoglycaemia. Galactose tolerance tests are abnormal in liver disease since the ability to convert galactose to glucose is impaired.
12. BSP test (Bromosulphalein test): The intravenous injection of sulfobromophthaline is given and then BSP concentration is measured in plasma. BSP is conjugated with glutathione and is excreted in a manner similar to that of bilirubin. An increase in the retention of BSP is indicative of liver dysfunction.
13. Impaired prothrombin time: This test measures the clotting time. Increases prothrombin time may indicate liver damage.
14. Elevated enzymes: Lactic dehydrogenase, Transaminase(glutamic-oxalacetic and glutamic –pyruvic), alkaline phosphatise, leucine amino peptidase, 5’ nucleotidase, phopho-hexose isomerase.
15. In urine: Bile salts, Bile pigment, urobilinogen