Week 19 - Cases 1,2,3,4 and passmed Flashcards
what are the causes of microcytic anaemia
- there are four
- MCV <80
- iron deficiency anaemia
- thalassaemia
- sideroblastic anaemia
- anaemia of chronic disease
what are the causes of normocytic anaemia
- there are 7
- MCV 80-100
- acute blood loss
- early iron deficiency anaemia
- renal disease
- haemolytic anaemia
- malaria
- sickle cell disease
- aplastic anaemia
what are the causes of megaloblastic anaemia
- there are 2
- MCV >100
- B12 deficiency
- folate deficiency
what are the causes of non-megaloblastic macrocytic anaemia
- there are 2
- MCV >100
- alcoholism
- liver disease
what kind of cells are seen in iron deficiency anaemia
pencil cells
what may be seen on a blood film in B12/ folate deficiency
hyper segmented neutrophils
what are the causes of iron deficiency anaemia
- dietary in origin, due to lack of red meat, or green vegetables in the diet
- due to gastrointestinal blood loss and is a must not miss diagnosis
- in females, due to loss during menstraton
if a patient has an iron deficiency anaemia, what would constitute red flag symptoms and require a 2 week wait referral to exclude cancer
Urgently refer (appointment within two weeks) people:
- aged 40 and over with unexplained weight loss and abdominal pain
- aged 50 and over with unexplained rectal bleeding
- aged 60 and over with either:
– iron deficiency anaemia
– OR alteration in bowel habit - who have positively tested for occult blood in their faeces
what does ferroportin do
controls the release of iron from the intestinal enterocytes into the blood stream and the release of iron from the marrow macrophages for eryhtropoiesis
what does hepcidin do
in turn controls the levels of ferroportin in an inverse manner
what does an increase in hepcidin do
causes ferroportin to degrade, reducing ferroportin levels prevents iron release from GI tract enterocytes into the blood stream and also traps iron in the marrow macrophages, thus reducing total iron bio-availabiliy
therefore what happens when iron is plentiful and the transferrin saturation is high
less iron is absorbed and fewer red cells are produced in the bone marrow
what happens in inflammation when there are high levels of IL6
the same mechanism is activated, explaining the classical marrow iron findings of the normocytic, normochromic anaemia of chronic disease; with excess iron in the free and marrow particle marcophages but no iron in the eryhtroblasts
what does the lack of production in anaemia of chronic disease also explain
why sometimes this type of anaemia can be hypochromic and is not always normochromic and normocytic
what happens if there is a decrease in hepcidin
it promotes iron absorption from the gut and releasing iron rom the marrow macrophages to assist increased erythropoiesis
what happens does a low TFR situation inhibit in iron deficiency and what does this lead to
a low TFR situation inhibits hepcidin and ferroportin increases this promoting iron absorption and availabilityg
there are increased levels of what in haemolytic anaemia
increase in the levels of growth differentiation factor 15