Bilirubin Flashcards
cregler niger syndrome
lack of UGP
- causes collection of billirubin in the blood
- glucuronyl transerase deficiency.
- early buildup causes kernicterus on newborns
dudin johnson syndrome
mutation in MR2P- causes conjugated bilirubin
Causes of increased unconjugated bilirubin in neonates
- physiological jaundice of the newborn
- hemolytic disease owing to Rh or ABO incompatibility
- presence of breast milk hyperbilirubinemia caused by alpha- glucoronidase in breast milk that causes the hydrolysis of conjugated bilirubin in the neonate
- usually due to an underdeveloped liver
causes of conjugated hyperbilirubinemia are
neonatal hepatisis and billiary atresia
gilberts syndrome
transport and conjugation defect, bilirubin = 2-3 mg/dL
direct testing of bilirubin tests for ______ bilirubin
conjugated
indirect testing of bilirubin tests for _________ bilirubin
unconjugated
Bilirubin
transported in the blood to the liver bound to albumin
- in the hepatocyte the bilirubin is rapidly conjugated with glucuronic acid to produce bilirubin monoglucuronide and diglucuronide which is then secreted into the bile
- in the intestine the bilirubin is hydroized into unconjugated bilirubin which is then reduced by the microbed into 3 urobilirubins: stercobilin, mesobilin, and urobilin. they are orange brown pigments that give the stool and urine their colors
- is in a ZZ (trans) formation but when exopsed to light is a EE(cis) formation which is water soluble and more easily excreted in the bile
icterus
the deposit of bile pigment in the skin, mucos and scelera resulting in a yellow appearance
- can happen in the serum too
unconjugated billirubin
water insoluble
- causes jaundice
- soluble in alcohol
- elevated in kernicterus
Conjugated Bili
water soluble
- causes jaundice
- present in urine
Diazoreaction
bilirubin that reacts with Diazo without alcohol is direct bili
- reactions that occur after the addition of alcohol is indirect bilirubin
Urine testing
only conjugated is in the urine
- use fouchets test, a tablet test(ictotest), or a strip test (bilistix)
- blilirubin uria seen in biliary obstruction, hepatocellular damage, dubin- johnson syndrome, and rotor’s syndrome