DESCRIPTION:
In the cells of the liver parenchyma, bilirubin is separated from albumin and conjugated in the endoplasmic reticulum with glucuronic acid. Conjugated bilirubin is also called direct bilirubin.
DETERMINATION:
The concentration of conjugated bilirubin is determined photometrically with DPD reagent. The sample for analysis is serum or heparinized plasma. The stability of the sample is 3 days at 2°C – 8°C in the dark, or 3 months at -20°C. The sample for analysis must not be lipemic or hemolytic.
CLINICAL SIGNIFICANCE:
1) Physiological changes in the concentration of conjugated bilirubin Bilirubin from the reticuloendothelial system reaches the circulation where it binds to albumin and as such enters the liver sinusoids and from them into the cells of the liver parenchyma. About 300 mmol (18 mg) of bilirubin enters the liver daily. In the smooth endoplasmic reticulum, bilirubin is separated from albumin and conjugated with glucuronic acid into bilirubin-monoglucuronide and bilirubin-diglucuronide. In this way, the insoluble bilirubin changes into the soluble form of bilirubin and is excreted in the bile. The ratio between conjugated and unconjugated bilirubin in healthy people is constant. 2) Pathological changes in the concentration of conjugated bilirubin Type of jaundice – Hemolytic Children, Serum: 42.8-128, Urine: trace, Color of stool: brown Type of jaundice – Hemolytic Adults, Serum: 1.7-10.3, Urine: neg., Color of stool: brown Type of jaundice – Parenchymal Serum: 17.1-256, Urine: 2-4 +, Color of stool: light brown Type of jaundice – Obstructive Serum: 128-256, Urine: 4+, Stool color: light Type of jaundice – Normal serum Serum: 0-3.4, Urine: neg., Stool color: brown A) Increased values of conjugated bilirubin concentration in: Acute and subacute liver necrosis / Acute pancreatitis / Biliary cirrhosis / Liver cirrhosis / Cytomegalic inclusion disease / Dubin-Johnson syndrome / Hemolytic disease in newborns (Erythroblastosis fetalis) / Hepatolenticular degenerations / Jaundice with liver cell damage (newborns) / Pancreatic carcinoma / Leptospirosis / Rotor syndrome / Acquired hemolytic anemia (autoimmune) / Viral hepatitis
SIDE EFFECT OF DRUGS:
Reduced values:
methemalbumin (up to 22%)
Increased values:
amphotericin B, dextran, phenazopyridine, levodopa (concentration > 60 mg/L), methotrexate, nitrofurantoin, piroxicam, sulfapyridine, sulfasalazine
RESULT:
The reference interval depends on gender, age and the method of determination. The reference interval is displayed on each validated result.
3.20€