Anaemia Flashcards
what type of anaemia is iron deficiency?
microcytic (low MCV)
hypochromatic (low MCHC)
most common cause of iron deficiency anaemia?
blood loss
- menstruation
- GI bleed (often malignancy)
what type of anaemia is B12/folate deficiency?
macrocytic
megaloblastic
whats the difference between macrocytic and megaloblastic?
macrocytic = high MCV megaloblastic = high/normal MCHC
what is MCHC?
measure of concentration of haemoglobin within a blood cell?
so is normal in B12/folate deficiency as its nuclear maturation thats affected not Hb??
what to megaloblastic RBCs look like on blood film?
hypersegmented neutrophils
what can cause B12/folate deficiency?
pernicious anaemia (B12) malbsorption (B12 or folate)
how does B12/folate deficiency result in anaemia?
B12 and folate needed for DNA synthesis
deficiency results in large erythroblasts with immature nuclei (megaloblasts)
features of aplastic anaemia on blood tests?
pancytopaenia (low RBCs, WBCs and platelets)
low Hb
bone marrow features of aplastic anaemia?
hypocellular bone marrow with no abnormal cells
what can cause aplastic anaemia?
bone marrow failure of any cause really
eg - idiopathic, drugs, viral illness, inherited forms such as fanconi anaemia
most common anaemia in alcoholics?
B12/folate (macrocytic megaloblastic)
most common anaemia in otherwise well people who drink a lot of alcohol?
macrocytic non-megaloblastic
what can cause non-megaloblastic macrocytic anaemia?
macocytosis in excess alcohol drinkers hypothyroidism hepatic disease haemolytic anaemia myelodysplastic syndrome drugs asplenia
features of autoimmune haemolytic anaemia on blood tests?
normocytic (normal MCV)
normochromatic (normal MCHC)
low Hb
unconjugated hyperbilirubinaemia
what features on blood film indicate haemolysis (eg in autoimmune haemolytic anaemia)?
spherocytes
high reticulocyte count
(also high unconjugated bilirubin but not really seen on blood film)
how can autoimmune haemolytic anaemia be diagnosed?
direct antiglobulin test (direct coombs test) - shows auto-antibodies on surface of RBCs if positive
what is fanconi’s anaemia?
increased chromosomal breakage, rearrangements and deletions due to defective DNA repair
who is fanconi’s anaemia more common in?
people of ashkenazi jewish descent
physical features of fanconi’s anaemia?
abnormal/absent thumbs kidney malformations microcephaly hypogonadism high foetal Hb
features of fanconi’s anaemia on blood film?
aplastic anaemia
pancytopaenia
in which conditions can anaemia of chronic disease occur?
active malignancy
chronic conditions such as diabetes or RA
blood features of anaemia of chronic disease?
can be normocytic or microcytic
high ferritin
reduced total iron binding capacity
low Hb (but rarely below 8)
anaemia of chronic disease is basically the same as what other anaemia and how can they be separated?
basically same as iron deficiency
differentiated by presence of high ferritin and low TIBC in anaemia of chronic disease
why is ferritin high in anaemia of chronic disease?
secondary to underlying inflammatory process
how is anaemia of chronic disease diagnosed?
presence of chronic inflammatory disease and anaemia
blood features
how is anaemia of chronic disease managed?
treat underlying disorder
monitor Hb
blood transfusion in severe cases
what is hereditary spherocytosis?
condition where the RBCs are sphere shaped making them fragile and easily destroyed
most common inherited haemolytic anaemia in north europe
how is hereditary spherocytosis inherited?
AD
how does hereditary spherocytosis present?
jaundice (unconjugated bilirubin in all haemolytic anaemias) anaemia gallstones splenomegaly can have episodes of haemolytic crisis
what can cause haemolytic crisis in hereditary spherocytosis and what happens?
can be triggered by infection
causes more severe haemolysis, anaemia and jaundice
what is an aplastic crisis in hereditary spherocytosis?
where patients develop increased haemolysis, anaemia and jaundice without the normal bone marrow response of creating new RBCs (ie no reticulocytosis)
what often triggers aplastic crisis in hereditary spherocytosis?
parovirus infection (aplastic crisis after parovirus infection = buzzword for hereditary spherocytosis)
how is hereditary spherocytosis diagnosed?
fam history clinical features spherocytes on blood film raised MCHC (megaloblastic?) reticulocytes can be raised due to rapid turnover of RBCs
how is hereditary spherocytosis managed?
folate supplementation
splenectomy (stops destruction of fragile RBCs as they pass through the spleen?)
removal of gallbladder (if gallstones are a problem)
transfusions may be needed during acute crises
