conjugated bilirubin

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Related to conjugated bilirubin: Unconjugated bilirubin

di·rect re·act·ing bil·i·ru·bin

the fraction of serum bilirubin which has been conjugated with glucuronic acid in the liver cell to form bilirubin diglucuronide; so called because it reacts directly with the Ehrlich diazo reagent; increased levels are found in hepatobiliary diseases, especially of the obstructive variety.

conjugated bilirubin

See bilirubin.

conjugated bilirubin

Direct bilirubin Bilirubin chemically bound to a glucuronide in the liver, which is excreted in bile by the liver and stored in the gallbladder or transferred to the duodenum Ref range Direct BR: 0–0.3 mg/dL ↑ in Bile duct obstruction, cirrhosis, Crigler-Najjar syndrome, Dubin-Johnson syndrome, hepatitis. See Bilirubin.


an orange bile pigment produced by the breakdown of heme and reduction of biliverdin; it normally circulates in plasma and is taken up by liver cells and conjugated to form bilirubin diglucuronide, the water-soluble pigment excreted in the bile. Failure of the liver cells to excrete bile, or obstruction of the bile ducts, can cause an increased amount of bilirubin in the body fluids and thus lead to obstructive or regurgitation jaundice.
Another type of jaundice results from excessive destruction of erythrocytes (hemolytic or retention jaundice). The more rapid the destruction of red blood cells and the degradation of hemoglobin, the greater the amount of bilirubin in the body fluids.
Most bilirubin is excreted in the feces. A small amount is excreted in the urine as urobilinogen.

conjugated bilirubin
bilirubin that has been conjugated, mainly to glucuronic acid, in the liver and gives a direct result to the van den bergh test. High blood levels indicate obstructive or hepatocellular origin of the jaundice.
delta bilirubin
bilirubin diglucuronide
see conjugated bilirubin (above).
free bilirubin
see unconjugated bilirubin (below).
bilirubin toxicity
unconjugated bilirubin
bilirubin that has not been conjugated in the liver. It gives an indirect reaction to the van den bergh test. A high level of it in the blood is indicative of hemolysis or a lack of bilirubin clearance by the liver. Called also free bilirubin.
References in periodicals archive ?
Abnormally high levels of serum conjugated bilirubin will exceed the ability of the kidneys to handle them, and can be detected in the urine on dipstick and visually: the urine becomes very dark ("tea"-coloured).
Serum direct bilirubin concentration increases, as does the amount of conjugated bilirubin in the urine, leading to very dark urine.
This conjugated bilirubin is then excreted by the liver via the biliary system (gallbladder and ducts) into the gut.
A high blood-level of conjugated bilirubin (more than 20% of total bilirubin) is indicative of liver disease.
Differentiation between hyperbilirubinaemias (4) Unconjugated Split bilirubin test Conjugated bilirubin less than 20% of total bilirubin Urine colour Colourless Stool colour Yellow, brown, green Cause Can be physiological or pathological Implications High levels can cause brain damage (kernicterus)--refer to paediatrician if total bilirubin is greater than 200micromol/l Conjugated Split bilirubin test Conjugated bilirubin greater than 20% of total bilirubin Urine colour Yellow Stool colour Pale lemon, white, grey Cause Always pathological and indicates liver disease Implications Requires prompt referral to a paediatrician
Serum from a patient without myeloma and a comparable concentration of conjugated bilirubin was included as a control.
The incidence of immunoglobulin interfering with the Olympus conjugated bilirubin assay appears to be very low.
A concentration of conjugated bilirubin higher than that of total bilirubin may suggest the presence of a monoclonal immunoglobulin.
A single measurement of indicators in blood is not the best way to detect the effect of the metal, but it does describe an acute copper load in relation to other useful biochemical markers, such as Hb and conjugated bilirubin.
As a consequence, the observed high copper concentrations in the neonates, which correlated positively with the conjugated bilirubin and LD and negatively with Hb concentration, were probably attributable to the destroyed erythrocytes.