Search results
Results From The WOW.Com Content Network
The varied causes of hyperbilirubinemia are best understood from bilirubin metabolism. The total average daily production of bilirubin in humans is 4 mg/kg. 80% of which is derived from haemoglobin (Hb) produced by erythrocyte breakdown, with the remaining from heme proteins , like myoglobin and cytochrome , turnover. [ 5 ]
Rotor type hyperbilirubinemia is a distinct yet similar disorder to Dubin–Johnson syndrome [1] – both diseases cause an increase in conjugated bilirubin, but Rotor syndrome differs in that it is a result of impaired hepatocellular storage of conjugated bilirubin that leaks into plasma causing hyperbilirubinemia. [2]
The syndrome cannot cause severe indirect hyperbilirubinemia in neonates by itself, but it may have a summative effect on rising bilirubin when combined with other factors, [10] for example in the presence of increased red blood cell destruction due to diseases such as G6PD deficiency.
Hyperbilirubinemia may refer to increased levels of conjugated, unconjugated or both conjugated and unconjugated bilirubin. The causes of hyperbilirubinemia can also be classified into prehepatic, intrahepatic, and posthepatic. [21] Prehepatic causes are associated mostly with an increase of unconjugated (indirect) bilirubin. [21] They include:
Hereditary hyperbilirubinemia refers to a group of conditions where levels of bilirubin, a byproduct of red blood cell metabolism, are elevated in the blood due to a genetic cause. [1] Various mutations of enzymes in the liver cells, which breakdown bilirubin, cause varying elevated levels of bilirubin in the blood. [2]
Jaundice, also known as icterus, is a yellowish or greenish pigmentation of the skin and sclera due to high bilirubin levels. [3] [6] Jaundice in adults is typically a sign indicating the presence of underlying diseases involving abnormal heme metabolism, liver dysfunction, or biliary-tract obstruction. [7]
Dubin–Johnson syndrome is a rare, autosomal recessive, benign disorder that causes an isolated increase of conjugated bilirubin in the serum. Classically, the condition causes a black liver due to the deposition of a pigment similar to melanin. [2]
Hemolytic jaundice, also known as prehepatic jaundice, is a type of jaundice arising from hemolysis or excessive destruction of red blood cells, when the byproduct bilirubin is not excreted by the hepatic cells quickly enough. [1]