Haematology pathophysiology Flashcards
anaemia, pigmented gallstones, splenomegaly
hereditary spherocytosis
pathophysiology of HbC disease
point mutation in Hg –> glutamic acid to lycine
pathophysiology of sickle cell
point mutation in HgB (B haemoglobin)
glutamic acid to valine
pathophysiology of g6pd deficiency
X-linked recessive
lack of g6pd = reduced NADPH = reduced oxidised glutathione = RBC susceptible to oxidised stress
pathophysiology of pyruvate kinase deficieny
autosomal recessive
pyruvate kinase deficiency = low ATP = rigid RBC = elevated 2,3-BPG and decreased Hg affinity for Hg
pathophysiology of hereditary spherocytosis
autosomal dominant
defective proteins interacting with FBC membrane skeleton
pathophysiology of paroxysmal nocturnal haematuria
defect in PIG-A gene resulting in impiared GPI anchors = reduced inhibition of complement = haemolysis
small round RBC with no central pallor
spherocytes (hereditary spherocytosis)
burr cells
pyruvate kinase deficiency
howell jolly bodies
asplenia
haematuria in a patient with sickle cell
sickling in renal tubules = renal papillary necrosis
treatment for sickle cell anaemia and mechanism of action
hydroxyurea
increases HgF
features of G6PD on blood smear
heinz bodies
bite cells
haemoglobin crystals in RBC
HbC disease
CD55/59 negative
paroxysmal nocturnal haemoglobinuria
what anaemias show schistocytes on peripheral blood smear
schist = split ‘helmet cells’
found in microangiopathic or macroangiopathic haemolytic anaemia’s
due to destruction of blood vessels in extravascular haemolysis either from going through damaged/narrowed vessels (i.e. DIC, TTP, HUS, SLE) or from propsthetic valaves and aortic stenosis
what does the presence of bite cells indicate
oxidative haemolysis
found in G6PD deficiency and drug induced haemolytic anaemia
NOTE: drug induced haemolytic anaemia can be exacerbated by G6PD
causes of warm vs cold haemolytic anaemias
warm
- IgG, chronic anaemia
- SLE, CLL, drugs (beta lactams, methyldopa)
cold
- IgM, acute anaemia on exposure to cold
- cold and blue peripheries
- CLL, mycoplasma pneumoniae, glandular fever
drugs which can induce haemolytic anaemia
methyldopa, beta lactams, NSAIDS, immunotherapy, chemo
features of paroxysmal nocturnal haemoglobinurea
urine thats red in the morning and improves throughout the day
venous thrombosis
pancytopenia
CD55/59 negative
associated with acute leukaemia’s
