We have discussed the importance of liver tests in our previous blog. I would be describing each individual test today which is a component of a normal LIVER FUNCTION TEST or LIVER PROFILE. Whenever, someone is getting a liver test done, he should insist on getting values for all the below mentioned parameters.
- Bilirubin – This is what measures the level of jaundice in one’s body. The total bilirubin indicates the level of jaundice. The additional numbers mentioned along includes direct and indirect bilirubin. The addition of these two numbers is total bilirubin. Direct bilirubin is concerned with liver and higher the number, more severe is the liver injury. The indirect bilirubin is not always associated with liver damage and can be elevated in non-liver conditions as well. The normal value of total bilirubin is around 1 mg/dl. When the level of total bilirubin crosses 3 mg/dl, you start noticing yellow urine and eyes. Sometimes when the number is very high, even the skin of the body can appear yellow.
- SGPT (ALT) – This is the second test which is measured along with bilirubin. This is indicative of ongoing liver injury. This substance is released into the blood from the damaged liver cells. The value of ALT can indicate doctor on not only the cause of liver disease but also the severity of liver disease. The normal value is less than 40 IU in most laboratories. The higher the value, more severe is the ongoing liver injury. It can even rise to thousands in certain liver disease. The levels of ALT start coming down before the bilirubin as the liver starts recovering.
- SGOT (AST) – This test should always accompany SGPT tests. There are certain local laboratories which do not include this test along with SGPT to cut the costs. However, this is as important as SGPT in liver test. Although, less specific for liver disease, it is highly important tests as the ratio of SGPT and SGOT helps doctor decide the cause of liver disease and can help your Hepatologist decide on further tests. The behavior of SGOT is similar to SGPT. It rises when the liver damage is ongoing and improves before bilirubin. However, as the blood is cleared off SGOT before SGPT, the value tends to fall before SGPT starts normalizing.
- ALP and GGT – These tests are usually used in combination. Most of the laboratories do not include GGT as a part of routine liver tests and they need to be informed specifically to include the tests. These tests are important to help doctor pick up disease affecting the bile ducts. Higher-than-normal levels of ALP may indicate liver damage or disease, such as a blocked bile duct. All laboratories have different cut off of normal ALP. GGT sometimes is useful in deciding whether the patient who alleges to be free of alcohol is actually free or not.
- Protein – As a part of liver profile, total protein, albumin and globulins are mentioned. Albumin is synthesized by liver and fall in albumin would indicate usually a long standing or chronic liver disease. Albumin and Globlin ratio is quite useful for the doctor to decide on the chronicity of liver ailment. Those individuals with cirrhosis, as the disease progresses the ratio becomes less than 1.
- Prothrombin Time – This is a single most important test in acute liver disease to decide the prognosis. This is also the most neglected test and unless specifically asked for, laboratories would not add on to liver profile. Even if you have acute or chronic liver disease, if you would need liver transplant or not, whether you would need any blood products before undergoing a elective surgery or not would be guided by this test. The higher the value the severe is the liver damage. The sooner it starts improving the better the prognosis of surviving the liver damage.
The above mentioned tests are just for understanding of all individuals and each of these tests have multiple uses. If you have any abnormality in above mentioned tests, kindly contact your liver specialist to understand the type, severity and prognosis of your ailment.