Interpretation Of Lab Results

Liver Enzymes   Definition A liver enzyme is a protein that helps to speed up a chemical reaction in the   liver. Liver function tests are blood tests that are used to evaluate various functions of the liver - for example, metabolism, storage, filtration and excretion, which are often performed by liver enzymes. However, not all liver function tests are measures of enzyme function. • ALT - (alanine aminotransferase )   - was previously called SGPT is more specific for liver damage. The ALT is an enzyme that is produced in the liver cells (hepatocytes) therefore it is more specific for liver disease than some of the other enzymes. It is generally increased in situations where there is damage to the liver cell membranes. All types of liver inflammation can cause raised ALT.    • AST - (aspartate aminotransferase) which was previously called SGOT. This is a mitochondrial enzyme that is also present in heart, muscle, kidney and brain therefore it is less specific

What causes the enzymes to be raised in a Liver Function Test?     The reason why all or some of these enzymes become elevated in cases of liver disease is that they are normally contained inside the liver cells (hepatocytes). They only leak into the blood stream when the liver cells are damaged. Thus measuring liver enzymes is only able to detect liver damage and does not measure liver function in a sensitive way. Other tests can be done to check the ability of the liver to manufacture its vital proteins. These are tests for the proteins albumin, prothrombin, and various globulins and they show characteristic abnormalities in those whose liver function is abnormal.    Tests for Liver Function:-    What is a Liver Function Test?   Blood samples are analyzed for levels of specific enzymes in the blood stream – there are generally 5 – 6 specific things that are checked. Collectively these tests are called a “ Liver Function Test ” or LFT. These enzymes are what