Direct bilirubin in the blood

Direct bilirubin in the blood is one of the important types of bile tetrapyrroles - pigments. In addition to direct bilirubin, there is another type - indirect. First of all, let us recall what is bilirubin proper. It is a bilinogen derivative with an oxidized core, a yellowish-red hue. Myoglobin, peroxidase, catalase and hemoglobin periodically disintegrate, and the products of this process are formed into tetrapyrroles - pigments. The cleavage is carried out by specific cells that are located in the hematopoietic organ - the bone marrow and mostly in the liver and in the lymphoid organ - the spleen. Almost all bilirubin can be considered a "brainchild" of erythrocyte hemoglobin. When the red blood cells fulfill their function and begin to "age", they are transformed into the spleen into a free insoluble form of bilirubin, which the kidneys can not infer because of its high density. To the aid comes albumin, which is generally famous for its "transport" functions, it binds toxic indirect bile pigment and with the blood flow carries it directly to the liver ducts. Direct bilirubin in the blood is obtained by binding a free, indirect pigment with a specific acid - glucuronic acid. In this form, bilirubin is no longer dangerous to the human body, it dissolves well in the aquatic environment and is excreted normally with feces, and also partially with kidneys. Direct bilirubin is also called because it is easy to detect in laboratory tests by means of staining with reagent. Indirect pigment stains only after separation of proteins into the sediment under the influence of alcohol-containing liquids.

The reference values (norm) of the content of direct bilirubin in serum are 0-0.2 mg / dl or 0-3.4 μmol / l.

Direct bilirubin in the blood is the main marker showing how much the liver is affected, as well as the state of the external and intrahepatic ducts. By determining the level of direct bilirubin in the blood, hidden forms of latent hepatitis (jaundice) can be identified when the sclera and skin of a person do not stain in a symptomatically familiar yellowish color. Also, direct bilirubin in the blood helps determine the etiology of malignant seizures, according to the symptoms similar to cholelithiasis. Such mild symptoms are often similar to painful sensations in the ulcerative process in the initial section of the small intestine - the duodenum, with renal colic and others. When the direct bilirubin in the blood is higher than the indicated norm, this indicates concrements in the bile ducts, especially characterized by an increase in direct bilirubin in cases where the stone tightly closes the narrowed duct. Also, an elevated direct pigment in the blood signals about possible tumors - gall bladder or liver, hepatitis, the probability of the degeneration of the liver parenchymal tissue into fibrous - cirrhosis. In pregnant women, direct bilirubin may also be elevated if the process of gestation is accompanied by severe toxemia. Protein degeneration of hepatic cells - atrophy, hepatitis associated with syphilis, inflammatory process in the intrahepatic ducts - cholangitis (angiocholite), medicinal jaundice, intoxication with phosphoric drugs - this is far from a complete list of diseases indicated by direct bilirubin in blood exceeding the norm. If the disease is chronic and lasts a long time in a latent form, a blood test can show an excess of the norm of both direct and indirect bilirubin.

Direct bilirubin in the blood is determined by the serum analysis. The study is conducted in the morning, on an empty stomach. Increased bilirubin direct is called hyperbilirubinemia.

[1], [2], [3], [4]

Reasons for direct bilirubin elevated

• all types of viral hepatitis; 
• infectious liver disease; 
• all problems associated with poor functioning of the gallbladder (cholangitis, cholecystitis); 
• Cholestatic cirrhosis - biliary; 
• narrowing of the intrahepatic ducts, obstruction due to a pancreatic tumor; 
• helminthiases; 
• oncoprocesses; 
• hereditary hepatosis - Rotor syndrome; 
• pigmentary hepatosis - Dabin-Johnson syndrome.

Direct bilirubin in the blood together with its more toxic counterpart - indirect bilirubin in fact and make up the pigment of bile, that is, bilirubin. In the case when the amount of non-toxic bilirubin passes the normal limits, its excess seeks to find a way out in the skin, sclera of the eyes. The yellowish shade that they acquire is an indication of excess of the norm of direct bilirubin.