Acquired anaemias (Red cells 2) Flashcards
(39 cards)
what is the normal range of RBC count in a male > 70 yrs?
116 - 156 g/L
what is the normal range of RBC in a female > 70 yrs?
108-143 g/L
what is the normal range of RBC in male and females of 12-70yrs ?
males: 140-180 g/L
females: 120-160 g/L
what are the general clinical features of anaemia?
tiredness pallor dyspnoea ankle oedema dizziness chest pain
what are the red cell indices and why are they helpful measurements?
automated measurement of red cell size and haemoglobin content
MCV - mean cell volume
MCH - mean cell haemoglobin
gives a morphological description of anaemia and a clue to the cause
when investigating a suspected anaemia, what 2 first line investigations would you carry out?
red cell indices (MCV and MCH)
blood film
if the red cell indices showed a normocytic, normochromic anaemia, what further investigation would you do next?
reticulocyte count
if MCV, MCH and blood film showed macrocytic RBC, what further investigations would you do next?
vitamin B12 and folate
bone marrow biopsy
if MCV, MCH and blood film showed hypochromic and microcytic, what further investigation would you do next?
serum ferritin
you are investigating the cause of a patients anaemia.
blood results show:
- microchromic microcytic anaemia
- ferritin = normal
thalassaemia
secondary anaemia
you are investigating the cause of a patients anaemia.
blood results show:
- microcytic hypochromic anaemia
- ferritin = low
what is the diagnosis?
iron deficiency anaemia
where is iron stored at ?
stored as ferritin in the liver
where is iron absorbed?
in the duodenum
how is iron transported in the plasma?
bound to transferrin
what is the role of hepcidin?
synthesised by hepatocytes in response to increasing iron levels. it blocks ferroportin so it reduces the absorption of iron from the intestines and mobilisation from reticuloendothelial cells
what are causes of iron deficiency anaemia?
GI blood loss menorrhagia malabsorption - gastrectomy - coeliac disease
what is the commonest cause of vitamin B12 deficiency in the western world?
pernicious anaemia
whats the aetiology of pernicious anaemia?
autoimmune condition where there is malabsorption of dietary vitamin B12 due to lack of intrinsic factor
(vitamin B12 is required to produce RBC therefore if deficient you don have enough to make RBC)
how can you diagnose pernicious anaemia?
presence of antibodies against intrinsic factor
via blood test
what is the treatment for pernicious anaemia?
vitamin B12 i/m injections
loading dose then 3 monthly injections
a patient presents with signs of anaemia so you perform a blood test. on the blood test it shows megaloblastic anaemia.
what are the differential diagnoses?
vitamin B12 deficiency
- pernicious anaemia
- gastric/ileal disease
folate deficiency
- dietary
- increased requirements - haemolysis
- GI pathology i.e. coeliac disease
alcohol drugs i.e. methotrexate disordered liver function hypothyroidism myelodysplasia
what acquired haemolytic anaemias are intravascular and extravascular?
immune = extravascular non-immune = intravascular
what test can you carry out to determine if the haemolytic anaemia is immune or not?
direct antiglobulin test (Coombs test)
you carry out a direct anti globulin test to determine if the haemolytic anaemia is immune or not.
what will the test show which will indicate that it is immune?
the reagent will bind to the Ab on the red cell surface and cause agglutination (clump together)
if it wasn’t immune then then RBC wouldn’t have the antibodies on their surface so wouldn’t react
