What is haemolysis?
Red blood cells normally live for 120 days.
Some diseases cause premature breakdown of red blood cells.
At the end, cell is too fragile.
Cell membrane rupture.
Destroyed by macrophages in the spleen and bone marrow – Reticuloendothelial system.
What is haemolysis?
Haemoglobin splits and globin and heme release.
Heme consists of four pyrrole rings.
Heme ring open and release pyrrole rings.
Pyrrole will under go several reaction and bilirubin form.
Conjugated bilirubin turn to urobilinogen by bacteria in the intestine.
Excrete via stool.
Urobilinogen can be reabsorbed to blood.
5% excrete via urine.
Urobilinogen turn to urobilin by oxidization when expose to air.
Stercobilinogen turn to stercobilin by oxidization when expose to air.
Jaundice
Excess bilirubin in the extracellular fluid.
Detectable when the serum bilirubin >30-60 µmol/letter.
Haemolysis
increase unconjugated bilirubin in plasma.
Urobilinogen increase
Intrahepatic cholestasis
acute and chronic liver diseases including cirrhosis, hepatitis, drugs,
increase in both type bilirubins
Congenital hyperbilirubinaemias
Glibert’s syndrome
common type
2-5% of population with mild increase unconjugated bilirubin.
Asymptomatic
Crigler-Najjar syndrome
rare
Problem of conjugation
Increase unconjugated bilirubin.
Dubin-johnson syndrome
Defect in bilirubin handling.
Increase conjugated bilirubin.