It is the test used for the determination of BILIRUBIN concentration in the blood. Before testing we have to know what the BILIRUBIN is??
BILIRUBIN is the greenish yellow pigment A end product of hemoglobin degradation, excreted in the bile and then eliminated in feces. It occurs when the hemoglobin is degraded. Hemoglobin is released by the bursting of red blood cells. Iron is release from hemoglobin. The porphyrin portion of hemoglobin is converted into a bile pigment called the BILIRUBIN. This is released into the blood circulation, later removed from the body.
Now the BILIRUBIN test comes the normal BILIRUBIN concentration in blood is 0.5 mg/dl of plasma. But when this concentration is increased in produce certain type of disease. It should be eliminated from the body as it forms by the degradation of hemoglobin. In certain abnormal condition, this can rise to as high as 40mg/dl and much it becomes the conjugated type. The skin usually begins to appear jaundice when the concentration rises to about three times normal, that is above 1.5gm/dl.
Jaundice cause by increase BILIRUBIN level in blood or plasma. In which the skin become pale yellow due to its yellow color.
The most common causes of jaundice are:
1-incresed obstruction of red blood cells, with rapid release of BILIRUBIN into the blood.
2-Obstruction of the bile ducts or damage to the liver cells so that even the usual amounts of BILIRUBIN cannot be excreted into the gastrointestinal tract. Here the bilirubin is absorbed so the rate at which the bilirubin is absorbed is really good here and can also be counted with the ratio of the bilirubin formed to the bilirubin excreted out of the body.
Jaundice is of two types. First is hemolytic jaundice cause by the destruction of red blood cells. In this type the. THE EXCRETORY FUNCTION OF LIVER IS IMPAIRED, BUT BLOOD CELLS ARE HEMOLYZE so the liver cells cannot excrete the BILIRUBIN as quickly as it formed.
Second one is obstructive jaundice, caused either by the obstruction of bile ducts or by damage to the hepatic cells.
Testing of both the BILIRUBIN types is done in the chemical laboratories, used to differentiate between free and conjugated BILIRUBIN test in the plasma. A test called the VAN DEN BERGH can be used to differentiate between two. In hemolytic jaundice all the BILIRUBIN is free and in obstructive jaundice, it is mainly in the conjugated form. The BILIRUBIN being dangerous should be eliminated from body as it forms by the liver.