Bilirubin

Question 1

cregler niger syndrome

Answer 1

lack of UGP

• causes collection of billirubin in the blood
• glucuronyl transerase deficiency.
• early buildup causes kernicterus on newborns

Question 2

dudin johnson syndrome

Answer 2

mutation in MR2P- causes conjugated bilirubin

Question 3

Causes of increased unconjugated bilirubin in neonates

Answer 3

• 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

Question 4

causes of conjugated hyperbilirubinemia are

Answer 4

neonatal hepatisis and billiary atresia

Question 5

gilberts syndrome

Answer 5

transport and conjugation defect, bilirubin = 2-3 mg/dL

Question 6

direct testing of bilirubin tests for ______ bilirubin

Answer 6

conjugated

Question 7

indirect testing of bilirubin tests for _________ bilirubin

Answer 7

unconjugated

Question 8

Bilirubin

Answer 8

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

Question 9

icterus

Answer 9

the deposit of bile pigment in the skin, mucos and scelera resulting in a yellow appearance
- can happen in the serum too

Question 10

unconjugated billirubin

Answer 10

water insoluble

• causes jaundice
• soluble in alcohol
• elevated in kernicterus

Question 11

Conjugated Bili

Answer 11

water soluble

• causes jaundice
• present in urine

Question 12

Diazoreaction

Answer 12

bilirubin that reacts with Diazo without alcohol is direct bili
- reactions that occur after the addition of alcohol is indirect bilirubin

Question 13

Urine testing

Answer 13

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