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Hereditary Haemolytic Anaemias

Hereditary Haemolytic Anaemias. Hereditary Haemolytic Anaemias. Look at the red cell as a floppy bag of haemoglobin. A floppy bag with three “bits”. Hereditary Haemolytic Anaemias. Look at the red cell as a floppy bag of haemoglobin. Membrane. Hereditary Haemolytic Anaemias.

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Hereditary Haemolytic Anaemias

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  1. Hereditary Haemolytic Anaemias

  2. Hereditary Haemolytic Anaemias Look at the red cell as a floppy bag of haemoglobin A floppy bag with three “bits”

  3. Hereditary Haemolytic Anaemias Look at the red cell as a floppy bag of haemoglobin • Membrane

  4. Hereditary Haemolytic Anaemias Look at the red cell as a floppy bag of haemoglobin • Membrane • Haemoglobin

  5. Hereditary Haemolytic Anaemias Look at the red cell as a floppy bag of haemoglobin • Membrane • Haemoglobin • Various chemicals

  6. Hereditary malfunctions of the Hb molecule will be covered in other presentations

  7. Membrane Malfunctions Membrane malfunctions usually reduce the red cell’s flexibility. Thus shortening red cell lifespan Causing a haemolytic process

  8. Membrane Malfunctions e.g. hereditary spherocytosis normal red cell Spherocyte

  9. Membrane Malfunctions e.g. hereditary elliptocytosis normal red cell elliptocyte

  10. Membrane Malfunctions • There is a (hereditary) problem with those proteins that give the red cell shape. • Spectrin • Ankryn • Proteins 3.1, 4, etc • Glycophorins • Reduced flexibility gives shortened cell lifespan • Hence a haemolytic process

  11. Membrane Malfunctions • All membrane defects have varying clinical presentations • Some cause anaemias in the newborn • Some are chance findings in patients aged 80+ with chest infection • And there are cases in between the extremes

  12. Acquired Membrane Malfunctions • Something usually overlooked • Stuff added to membrane • target cells in liver disease • Altered membrane permeability • burr cells in renal disease • physically damaged cells • schistocytes in H.U.S

  13. The red cell membrane might be a floppy bag, but it’s important !

  14. Red Cell Metabolism • Remember !!!!! • Red cells have only those enzymes they were made with • can’t make more • Red cells are anaerobic • strange when you consider their function

  15. Red Cell Metabolism Glucose goes in Hexokinase turns it to G-6-P and then Two main biochemical pathways

  16. Red Cell Metabolism • Glycolysis • 2-3 diphosphoglycerate • Pyruvate kinase • Pentose phosphate shunt • Glucose - 6 - phosphate dehydrogenase • Though any enzyme may be deficient

  17. Red Cell Metabolism 2-3 diphosphoglycerate Glycolysis Glucose : 1-3 DPG | 3 DPG : etc Rappaport - lubering shuttle ------------- 2-3 DPG | 3 DPG : etc

  18. Red Cell Metabolism 2-3 diphosphoglycerate “shifts the oxygen dissociation curve” - what does that mean? - 2-3 DPG bonds deoxy-Hb avidly, thereby causing greater oxygen release to the tissues

  19. Red Cell Metabolism Pyruvate Kinase Glycolysis Glucose : PEP | Pyruvate + ATP : etc without PK this don’t happen

  20. Red Cell Metabolism Glucose - 6 - phosphate dehydrogenase Pentose phosphate shunt Glucose : G6P | 6PG : etc the etc includes production NADH and NADPH which doesn’t happen if G6PD is lacking

  21. Red Cell Metabolism Glucose - 6 - phosphate dehydrogenase & glutathione Glutathione (GSH) is a protein which mops up oxidative substances in the red cell. Glutathione reductase (GR) then recycles glutathione in a reaction that involves NAPD 2GSH + oxidative substance = GS-SG GS-SG + GR +NADH = 2GSH “oxidative substance” - what’s that then Drugs, food, and anti-malarials !

  22. Red Cell Metabolism • To summarise: • Membrane malfunctions • HS • HE • Acquired • Enzyme deficiencies • PK • G6PD • Haemoglobinopathies • later...

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