Haematology Flashcards
(104 cards)
How can you tell if an anaemia is caused by an issue with removal or production of RBCs
measure reticulocyte count
Causes of microcytic anaemia
iron deficiency
thalassaemia
anaemia of chronic disease
sideroblastic anaemia
causes of normocytic anaemia
acute blood loss anaemia of chronic disease CKD autoimmune rheumatic disease Endocrine disease haemolytic anaemia
Causes of macrocytic anaemia
vitamin B12 or folate deficiency alcohol liver disease hypothyroidism drug therapy e.g. azathioprine
How is iron absorpbed
intestinal haem transporter HCP1 actively transports iron into the duodenal epithelial cells where some binds to ferritin (intracellular store) and the rest circulates in blood bound to transferrin.
How is iron used
majority in haemoglobin
the rest in reticuloendothelial cells, hepatocytes and skeletal muscle cells as ferritin or haemosiderin
Serum test results in iron deficiency
low serum iron
high total-iron binding capacity
increase in transferrin receptors
low reticulocyte count
Treatment of iron deficiency
usually find a cause first
ferrous sulphate oral
ferrous gluconate if bad SE
parenteral iron (IV iron or IM iron) only in extreme cases.
what is anaemia of chronic disease
bone marrow is sick
second most common cause of anaemia and common in hospitalised patients
usually normocytic
Common causes of anaemia of chronic disease
tuberculosis crohns rheumatoid arthritis SLE malignant disease
what is pernicious anaemia
autoimmune disorder in which parietal cells of stomach are attacked resulting in atrophic gastritis and the loss of intrinsic factor production and hence b12 malabsorption
where is b12 absorped
terminal ileum using intrinsic factor (produced by parietal cells in stomach)
risk factors for pernicious anaemia
elderly
female
fair haired
autoimmune disease
Treatment for pernicious anemia
b12 injections (IM hydroxocobalamin)
how might you distinguish between a folate and b12 deficiency
no neuropathy in folate deficiency
treatment of folic acid deficiency
folic acid tablets WITH B12 unless known to be normal as can precipitate subacute combined degeneration of the cord
main causes of haemolytic anaemia
RBC membrane defects - hereditary spherocytosis
enzyme defects - glucose-6-phosphate dehydrogenase deficiency
haemoglobinopathies:
B thalassaemia
A thalassaemia
sickle cell disease
autoimmune haemolytic anaemia
features of haemolytic aneamia (bilirubin)
high unconjugated bilirubin high urobilinogen high stercobilinogen (dark stool) splenomegaly bone marrow expansion reticulocytosis
hereditary spherocytosis summary
autosomal dominant
deficiency in structural protein spectrum
sphere shaped RBC get stuck in spleen and cause premature haemolytic and splenomegaly
presentation of hereditary spherocytosis
jaundice at birth can have delayed jaundice anaemia splenomegaly ulcers on leg gall stones
aplastic anaemia after infections (particularly parvovirus)
treatment of hereditary spherocytosis
splenectomy delayed until after childhood (risk)
post-op life-long penicillin prophylaxis
G6PD deficiency summary
heterogenous x-linked (more common in males)
G6DP reduces NADP to NADPH which is essential for protecting RBCs from oxidative stress
Leads to reduced RBC lifespan
Presentation of G6PD deficiency
asymptomatic
drug-induced haemolytic: aspirin antimalarials (quinine, chloroquine) nitrofuratonin fava beans
In attacks:
rapid anaemia
jaundice
Results/treatment of G6DP attacks
irregular cells on film Bite cells (cells with indentation in) reticulocytosis G6PD enzyme levels will be low but can be falsely high blood transfusion may be life saving