Concepts in haematology Flashcards
what are causes of low blood count
increased destruction/loss: haemorrhage, haemolysis
reduced production: chemo, parovirus B19
redistribution: liver disease, portal hypertension, splenomegaly
what are causes of high blood count
increased production with stimulus: infection, hypoxia, high altitude, COPD
increased production with no stimulus: malignancy
redistribution: steroids
-cytosis / -philia = high/low count
high
-paenia = high/low count
low
what is the difference between thrombocytosis and thrombophilia
thrombocytosis = increased platelets thrombophilia = excess clotting
what underlying malignancies may be present with an isolated thrombocytosis
LEGO C lung endometrial gastric oesoophageal colorectal
define hyperplasia
increased production
define dysplasia
disordered production
define hypoplasia
decreased production
define aplasia
no production
what is the erythron
intact cellular mechanism generating RBCs
what are reticulocytes
immature RBC just released into the bloodstream from bone marrow
what is the function of B12 and folate
cell division: DNA synthesis and nuclear maturation
what is the function of iron
to make haem
which organ detects hypoxia
kidneys
release EPO in response
what is erythroid hyperplasia
increased production in RBCs
thrombocytosis is common with microcytic anaemia, true or false
true
what is low serum ferritin suggestive of
iron deficiency
what is serum ferritin
an indirect reflection of tissue ferritin which stores Fe3+
ferritin is also an acute phase protein
causes of high serum ferritin
high iron levels
inflammation, infection
how can you assess response to iron replacement therapy in iron deficiency anaemia
reticulocyte count should increase
Hb levels
what is extramedullary haematopoeisis
blood cell production outside the bone marrow
what is a complication of regular blood transfusions
iron overload
what are spherocytes
circular RBCs, not biconcave in shape
what is hereditary spherocytosis
genetic condition with abnormal proteins in RBC membrane resulting in spherical shape
jaundice and fatigue following a cold
what investigations can be done for haemolysis
FBC bilirubin - high LDH - marker of cell turnover Haptoglobin - binds free Hb reticulocytes - high antibodies by DAT
Haptoglobin is low/high in haemolysis, and why
low
haptoglobin binds free iron, if there is a lot of iron from haemolysis then a lot of haptoglobin is used up meaning FREE haptoglobin is low
what is IAT testing
indirect anti-globulin test
- used for crossmatching
what is DAT
direct anti-globulin test
- autoimmune haemolytic anaemia
spherocytes have a shorter lifespan, true or false
true
splenectomy increases/decreases RBC lifespan
increases
the spleen is where RBC are destroyed, if it is not there, they hang around for longer
risks of splenectomy/hyposplenism
infection and immunosuppresion
risks of clots
big operation
need vaccinations before
What is meant by reactive changes on the blood count
from underlying inflammatory changes or iron deficiency you can get neutrophilia, leucocytosis, thrombocytosis
What can cause a high Hb/Hct
dehydration (rule out hypovolaemia, DKA, diuretics)
cigarette smoking
high altitude
COPD
what is anisocytosis
how large red cell distribution width is (RDW)
causes of neutrophilia
steroids smoking trauma infection malignancy
what is rouleaux
stacked/clumped RBCs due to presence of acute phase proteins in inflammatory conditions eg autoimmune
what is pancytopaenia
reduced blood cells all over
what is anisopoikilocytosis and in which condition is it seen
red blood cells are of different sizes and shapes
aniso = size
poikilo = shape
B thalassaemia major
what are crenated red cells (echinocytes)
abnormally contracted cells - look shrivelled (eg when placed in a hypertonic solution)
PK deficiency
drugs
why do you get splenomegaly
presence of defective cells causes them to be destroyed which is done in the spleen - hyperplasia at site of destruction
extravascular haemolysis
thalamssaemia
