Liver Function Test (LFT) - How to correlate different readings?

A liver function test is a blood test that determines the amount of protein and liver enzymes in the bloodstream that is excreted by a damaged liver. The liver function tests measure the health of the liver with the help of liver enzyme tests. It examines the level of protein, enzyme, and bilirubin in the blood. 

Under normal conditions, the liver enzymes stay within the liver cell, but in case of any liver injury, it excretes in the blood, and liver enzyme levels increase in the body. Hence, a hepatic function panel is done to check the alt liver enzyme for the possibility of liver damage or liver disease. 

Thus, if the liver test results are higher than normal, it indicates a liver problem. It is done with a small quantity of blood taken from the body and, on average, takes two days for the reports to come out. If the liver function test comes abnormal, then this denotes the irregularity in liver functioning.

A liver’s prime function is to detoxify the body’s metabolism by synthesizing proteins and enzyme production for digestion. Apart from this, the liver regulates red blood cells and glucose amalgamation in the body. Hence, a Liver Function Test (LFT) points out what is wrong in liver functioning and identifies the cause of liver damage.  

What is included in a Liver Function Test?

Coagulation panel: 

This test assesses the blood’s capacity to clot normally using various protein components produced by the liver. 

Albumin:

It is a protein present in the liver that helps to keep fluid in the bloodstream without going into the tissues. If the alt hepatic enzyme level is lower than average, which is around 3.5 to 5 g/dL, it could be due to chronic liver disease.  However, irregular albumin levels can be caused by a variety of other factors as well. Thus, liver tests will help to diagnose the real issue appropriately. 

Bilirubin:

It is commonly known for digesting red blood cells in daily life and is excreted as bile in the form of feces. Its usual range is 0.1 to 1.0 mg/dL, so any increase outside of this range can result in serious blood cell damage. Thus, with the help of a hepatic function panel, doctors can diagnose if there is any symptom of Bilirubin irregularity in the bloodstream.  

Platelet count: 

Standard platelet counts range from 150,000 to 400,000 per milliliter. Any changes in these numbers can lead to serious liver disease. As a result, a liver enzyme test can confirm the body’s platelet count. 

Glucose:

The liver is responsible for supplying glucose to the body. It is in charge of releasing glucose into the bloodstream in order to provide energy. As a result, a liver function test can assist in identifying and diagnosing diabetic complications. 

Gamma-glutamyl transpeptidase: 

This enzyme’s increased concentrations indicate the likelihood of liver injury. The typical range for GT is 9 to 48 U/L; if it is discovered above this range, there is a risk of liver injury. 

ALP (alkaline phosphatase):

Alkaline phosphatase levels range from 45 to 115 U/L on average. If the liver produces a higher level of alkaline phosphatase, this indicates the possibility of liver injury. 

LD or LDH (Lactate dehydrogenase):

Lactate dehydrogenase has a normal range of 122 to 222 U/L. The liver test results show the level of Lactate dehydrogenase in the body. Any type of change in the Lactate dehydrogenase can be a symptom of diseases like anemia or tissue damage. 

Why do doctors use the Liver function test?

Clinicians use the Liver Function Test for a variety of reasons.  A liver test can assist doctors in determining the true cause of the disease. 

A rise in Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) levels, for example, will be considered an indication of liver injury. A high level of alkaline phosphatase (ALP) or gamma-glutamyl transferase (GGT) in the blood indicates the presence of disorders such as bile duct blockage or the risk of bone disease. 

Furthermore, a low or high range of Albumin and total protein can indicate liver cancer. Similarly, a higher Bilirubin level might also be a sign of diseases like jaundice. 

Interpreting a Liver Function Test 

If the liver proteins and enzymes do not fall into the normal range. It is a warning sign that your liver is not working properly. It could be caused by a disease, inflammation, liver damage, or by an infection in the liver. 

For identifying liver problems, a Liver Function Test (LFT) is ideal. Interpreting a liver function test is not easy, and it is advisable to consult with a medical team. The level of enzymes and protein are the most important elements that are checked, and their quantity helps doctors draw an effective conclusion for their patients. 

Hence, a liver blood test helps doctors diagnose diseases such as hepatitis B and hepatitis C. It helps them in diagnosing infections or medical conditions like high blood pressure, triglycerides, or even diabetes.