Haemolytic Anaemia Flashcards
Haemolytic anaemia
⬆️ rate of RBC destruction may be intrinsic or extrinsic to RBC
Clinical consequences of haemolytic anaemia
Anaemia
Splenomegaly
Jaundice
Role of Pyruvate Kinase in glucose metabolism
Catalyses conversion of PEP -> Pyruvate
Isoenzymes of Pyruvate kinase (4)
PK-L
PK-M
PK-M2
PK-R
Pyruvate kinase deficiency
PK-R functionally defective
~400 patients but ~100 gene mutations - missense, splicing, insertions, deletions
Role of glucose-6-phosphate dehydrogenase
Oxidises G6P->6PG (6-phosphogluconolactone)
Reduces NADP -> NADPH
Glucose-6-phosphate hydrogenate deficiency
Balanced polymorphism (protection against malaria)
Majority asymptomatic unless exposed to oxidising agent
Small number have chronic haemolytic anaemia
Presentations of Glucose-6-phosphate dehydrogenase deficiency
Neonatal jaundice
Acute haemolytic anaemia
Chronic non-spherocytic haemolytic anaemia
Oxidising agents that cause haemolysis
Fava beans
Antimalarials
Analgesics
Antibacterial
Sulfonamides
Methylene blue
RBC Membrane composed of:
Ankyrin
Spectrin
Dematin
Carbohydrates
Etc
Hereditary spherocytosis
Congenital haemolytic anaemia w/ gene defect -> formation of spherocytic RBC
Abnormalities of genes in hereditary spherocytosis
Ankyrin gene
Anion exchanger gene
Protein 4.2
Spectrin gene
Test for hereditary spherocytosis
Osmotic fragility test
HS RBC burst sooner than biconcave disc
Paroxysmal Nocturnal Haemoglobinuria
Acquired RBC disorder. Acquired clone
Acquired mutations found in PIG-A gene
Intravascular haemolysis
Aplastic anaemia
Venous thrombosis
PNH RBCs have missing GPI anchored proteins:
CD55/Decay Accelerating Factor/DAF
CD59/Membrane Inhibitor of Reactive Lysis/MIRL
