HYPERBILIRUBINEMI Prof.Dr.Arzu SEVEN. HYPERBILIRUBINEMI (Bilirubin>1mg/dl in blood) Types of...
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Transcript of HYPERBILIRUBINEMI Prof.Dr.Arzu SEVEN. HYPERBILIRUBINEMI (Bilirubin>1mg/dl in blood) Types of...
HYPERBILIRUBINEMI
Prof.Dr.Arzu SEVEN
HYPERBILIRUBINEMI(Bilirubin>1mg/dl in blood)
• Types of bilirubin:• İndirect bilirubin=free
bilirubin=unconjugated bilirubin
• Free bilirubin en route to liver from RES, where it is produced from the breakdown of heme porphyrins.
.
• As it is water _insoluble, it requires methanol to be coupled with diazo reagent
• Direct bilirubin=conjugated bilirubin=bilirubin glucuronide:
• Bilirubin that is ready to be excreted into the bile
• As it is water soluble, it can react directly with diazo reagent.
Only conjugated bilirubin can occur in the urine .
• DELTA bilirubin:• Conjugated bilirubin that is covalently
bound to albumin, has a longer half life in plasma than conventional conjugated bilirubin
.
• It remains high during the recovery phase of obstructive jaundice after the remainder of conjugated bilirubin has decreased to normal level.
• Hyperbilirubinemi may be due to:• a)production of more bilirubin than normal
liver can excrete:PREHEPATİC• b)failure of damaged liver to excrete
normal amounts of bilirubin, impaired hepatic uptake, conjugation or secretion of hepatic bilirubin:INTRAHEPATIC
• C)obstruction of the excretory ducts of liver:POST HEPATIC
• Depending on the type of bilirubin present in plasma, hyperbilirubinemia may ve classified as:
• 1)retention hyperbilirubinemia due to overproduction.
• 2)regurgitation hyperbilirubinemia due to reflux into the bloodstream because of biliary obstruction.
• Because of its hydrophobicity only unconjugated bilirubin>20-25mg/dl can cross the blood_brain barrier into the central nervous system.
• Toxic encephalopathy due to hyperbilirubinemi (KERNİCTERUS) can occur in retention hyperbilrubinemia.
• Choluric jaundice occurs in regurgitation hyperbilirubinemia.
• Acholuric jaundice occurs only in the presence of excess unconjugated bilirubin.
.
• Obstruction of the biliary tree is the commonest cause of conjugated hyperbilirubinemia .
Blockage of the hepatic or common bile ducts,most often due to a gallstone or pancreas head cancer
• Conjugated bilirubin can not be excreted due to obstruction
it regurgitates into hepatic veins γ lymphatics
it appears in blood γ urine
(choluric jaundice)
• Cholestatic jaundice: all cases of extrahepatic obstructive jaundice
Dubin Johnson Syndrome
• Benign autosomal recessive disorders • Conjugated hyperbilirubinemia in
childhood or during adult life• Mutations in the gene encoding MRP-2,
the protein involved in the secretion of conjugated bilirubin into bile
• Centrilobuler hepatocytes contain abnormal black pigment derived from epinephrine .
Rotor Syndrome
• Rare benign condition
• Chronic conjugated hyperbilirubinemia
• Normal liver histology
• Abnormality in hepatic storage
Neonatal physiologic jaundice• Accelerated hemolysis around the time of
birth • Immature hepatic system for the
uptake,conjugated and secretion of bilirubin• enzyme activity
UDP_glucuronic acid • Therapy: Phenobarbital
Phototherapy (blue light)
Crigler –Najjar Syndrome Type I(congenital nonhemolytic jaundice)
• Rare
• Autosomal recessive
• Severe congenital jaundice
(bilirubin>20mg/dl)
• Fatal within 15 months of life
• Phototherapy
Crigler –Najjar Syndrome Type II
• Rare
• Inherited
• More benign than type I
• bilirubin<20mg/dl
• Phenobarbital
Gilbert Syndrome
• 30% of enzyme activity is preserved
• Harmless
Toxic Hyperbilirubinemia
• Toxin- induced liver dysfunction due to choloroform, arsphenamines, acetaminophen, carbon tetrachloride, hepatitis virus, cirrhosis
Amanita mushroom poisoning