62. Jaundices (Jaundice with high (+) UCB occurs because of.. (UCB…
Jaundice- skin and eyes appear yellowish due to increased blood levels of bilirubin.
normally, unconjugated bilirubin is metabolised in the liver hepatocytes by UGT enzyme into conjugated bilirubin.
If hepatocytes die, UGT cannot perform and UCB and CB will be released in the blood.
yellow colour due to >2.5mg/dL serum level of bilirubin
sclera has a lot of elastin which has high affinity of bilirubin, usually appears yellow first.
Jaundice with high (+) UCB occurs because of..
extravascular haemolytic anaemia
RBCs broken down earlier than usual by macrophages
rbcs dont form correctly in bone marrow, broken down by macrophages
UCB OVERLOAD ON HEPATOCYTES
excess UCB remains in blood
max CB released, goes to bile
(+) risk of pigmented bilirubin gallstones
to duodenum where converted to UBG (urobilinogen)
some UBG recycled into blood, oxidised to UB (urobilin)
UB excreted by kidneys
physiologic jaundice of newborn
newborn livers have (-) UGT enzyme
UCB may accumulate, fat soluble, collect in basal ganglia
- low UGT activity
hemolysis can cause build up of UCB
Crigler Najjar syndrome
- no UGT activity
extremely (+) UCB in blood, kernicterus, fatal
Jaundice with high (+) CB occurs because of..
Dubin Johnson syndrome
- autosomal recessive disorder
deficiency of transport protein MRP2 that moves CB to bile duct from hepatocytes
MRP3 unregulated, moves CB back into blood, accumulates
- bile flow blocked
blockage causes(+) pressure in bile duct
bile w/ CB leaks through tight junctions back into blood
bile salts, acids and cholesterol also leaks
Jaundice with high (+) UCB and CB occurs because of..
hepatocytes infected, die
(+) UCB in blood
let bile leak into blood
(+) CB in blood