1- intro to anaemia & microcytic anaemia Flashcards
what is anaemia?
reduced total red cell mass
what are normal haemoglobin and haematocrit levels?
normal haemoglobin is <130g/L male and <120g/L female
normal haematocrit is <0.38 male and <0.37 female
what is haematocrit?
ratio of whole blood that is red cells
what is normal response to anaemia?
make more RBC by reticulocytosis
what are reticulocytes?
cells that have just left bone marrow (young normal RBCs), they have DNA&RNA since were just making haemoglobin, they stain blue/black and since they’re red then it makes them look purple
so they’re big & a bit purple and they increase RBC production
what are 2 super general causes of anaemia?
- decreased production (low reticulocyte)
- increased destruction of cells (high reticulocyte) like blood loss or haemolysis
what causes decreased production of RBCs causing anaemia? (sort of general 2 areas where there’s a problem which leads to decreased production)
- hypoproliferative anaemia (reduced amount of erythropoiesis, bone marrow not making enough blood cells) →can be caused by dodgy kidneys etc
- maturation defect (where bone marrow tries to make but just not very well so none released since dysfunctional RBCs made). can be either failure to make haemoglobin which is cytoplasmic defect or failure of cell division which is nuclear defect
what is MCV? (if small what problem, if big what problem?)
mean cell volume
if small then haemoglobin problem
if big then cell division problem
where is haemoglobin made?
in cytoplasm of red cell precursors
what are 3 components required to make haemoglobin?
- iron
- polyphyrin ring
- globin chains
*if lacking any of these then microcytic anaemia
why does lack of haemoglobin mean RBC too small?
accumulation of haemoglobin in cytoplasm of cell is one of the signals to say stop dividing time to leave. so without enough haemoglobin cell keeps dividing for longer than should make under coloured and smaller cells
what are 5 causes (mnemonic) for microcytic anaemia?
T = thalassaemia →globin deficiency (can’t make haemoglobin)
A = anaemia of chronic disease (enough iron in body but not delivered to red cells properly because inflammation & other illness)
I = iron deficiency
L = lead poisoning (very uncommon) - causes problem with porphyrin ring
S = sideroblastic anaemia (congenital, enzyme deficiency to make porphyrin ring)
what transports iron? where is iron stored?
- transferrin (2 binding sites)
- ferritin (large protein with up to 4000 ferric ions can be stored)
what are some causes of iron deficiency?
- diet (absolute + relative), consuming too little
- losing iron from blood loss like GI or menstruation
- absoprtion issues like coeliac or crohn’s
what is treatment of iron deficiency?
iron supplement ferrous fumarate 210 mg , take with vit C/orange juice and ideally 30 min before meal
can also be given IV
- sodium feredetate (better for kids as liquid, 2.5mls)
= monitor response for 4-6 weeks. often continue for 2-3 months
