Anaemia Flashcards
how can anaemia be broadly classified? (think very broad)
RBC size
mechanism
what are the ways of classifying anaemia based on rec cell size and give their reference values
macrocytic (MCV>100)
normocytic (MCV80-100)
microcytic (MCV<80)
what is meant by megaloblastic anaemia?
a type of macrocytic anaemia
occurs due to impaired DNA synthesis in RBC production
give causes of macrocytic anaemia
B12 deficiency folate deficiency alcoholism liver disease drug side effects (azathioprine, methotrexate) hypothyroidism
give examples of megaloblastic anaemia
B12 deficiency
folate deficiency
give causes of normocytic anaemia
anaemia of chronic disease
give causes of microcytic anaemia
iron deficiency
thalassaemia
sideroblastic anaemia
what is meant by a dimorphic appearance?
when there are two populations of red cells on a blood smear
what can give a dimorphic appearance on a blood film?
blood transfusion e.g. for iron deificienct anaemia
sideroblastic anaemia
what does ferritin reflect?
iron stores
also acute phase reactant
what is the cut off required for transfusion?
Hb<7
how is iron absorbed?
in bowel and urinary tract via iron channels
some iron is stored in cells bound to ferritin
some is exported from the cell by ferroportin and binds to transferrin in the blood
how is iron excreted?
via shedding of the mucosal cells
where are ferroportin channels present?
bowel mucosa
macrophages
what happens to ferroportin channels in anaemia of chronic disease?
gets blocked by hepcidin to try and shut down iron supply to bacteria
