Liver function test to detect liver disease, what is the procedure?

Liver function tests are blood tests used for diagnosis and screening of liver function. This series of tests measures the enzymes that liver cells release in response to damage or disease. Below is more detailed information on this common test.

What is checked during liver function tests?

The liver blood test usually consists of six separate tests that are done on a single blood sample. This series of tests includes:

1. Alanine aminotransferase (ALT)

An enzyme called ALT is released from liver cells. In general, ALT is also present in the bloodstream but at low levels. The normal range of ALT levels in the blood is between 5 and 60 IU / L (International Units per Liter).

ALT can leak into the blood vessels when there is a disease in the liver or there are liver cells that are damaged or die. Elevated ALT in the blood can be triggered by any type of hepatitis (viral, alcoholic, or drug induced). In addition, shock or drug toxicity can increase ALT levels.

Regardless of how much ALT is in the blood, inflammation or liver cell death can only be monitored with a liver biopsy. Although the ALT level in the blood vessels is a direct quantitative measurement, it cannot be used to diagnose liver damage or disease progression.

2.Aspartate aminotransferase (AST)

AST is a mitochondrial enzyme found in the liver, heart, muscles, kidneys and brain. In most cases of liver damage, ALT and AST levels increase by a ratio of about 1: 1. The normal range of AST levels in the bloodstream is between 5 and 43 IU / L.

3. Alkaline phosphatase (ALP)

ALP is found in many body tissues (intestines, kidneys, placenta, and bones) and is produced in the bile ducts and sinusoidal membranes of the liver. If the bile duct becomes blocked, ALP levels will rise. In addition, ALP will increase in case of cirrhosis, sclerosing cholangitis and liver cancer.

In addition, bone disease, congestive heart failure, and hyperthyroidism can cause unexpectedly high ALP levels. Increased ALP levels can be caused by liver problems if GGT levels are also raised. The normal range of ALP levels in the blood is between 30 and 115 IU / L.

4. Bilirubin

Bilirubin is a yellow liquid that is present in the bloodstream and is produced in the liver by red blood cells that die with age. The liver filters old red blood cells from the bloodstream in a chemical modification process called conjugation. These cells are then released into the bile, then channeled and some of it is reabsorbed into the intestine.

Bilirubin levels can increase due to various diseases, including liver disease. If the liver is damaged, bilirubin can leak into the bloodstream and cause jaundice (jaundice), which is yellowing of the eyes and skin accompanied by dark urine and light-colored stools. The causes of increased bilirubin levels include:

Viral hepatitis
Bile duct blockage
Cirrhosis of the liver
Other liver diseases

The total bilirubin test measures the amount of bilirubin in the blood vessels. Total normal bilirubin levels range from 0.20 to 1.50 mg / dl (milligrams per deciliter). The direct bilirubin test (bilirubin direct) measures the bilirubin produced in the liver. Normal direct bilirubin levels range from 0.00 to 0.03 mg / dl.

5. Albumin

Albumin is the most abundant protein in the bloodstream and is produced by the liver. The albumin test is the easiest, most reliable and inexpensive. A liver that doesn't produce enough protein with proper function can lead to low albumin levels. Initially albumin levels are usually normal in chronic liver disease until eventually cirrhosis and / or other liver diseases become serious enough and prevent the production of protein by the liver.

Additionally, malnutrition, some kidney diseases, and other, rarer conditions can cause decreased albumin levels. Albumin maintains blood volume in veins and arteries. If albumin levels drop significantly, fluid can leak from the bloodstream into the surrounding tissue, causing swelling in the ankles and soles. The normal range of albumin levels in the blood is between 3.9 and 5.0 g / dl (gram / deciliter).

6.Total Protein (TP)

The TP is a blood test that measures albumin and all other proteins in the bloodstream, including antibodies that help fight infection. A variety of different reasons can cause an abnormal increase or decrease in protein levels, such as liver disease, kidney disease, blood cancer, malnutrition, or abnormal body swelling. Normal levels of protein in the bloodstream range from 6.5 to 8.2 g / dl.

Hello Health Group does not provide medical advice, diagnosis or treatment.