blood and anaemia Flashcards
normal number of RBCs
3-5x10^12/litre
normal number of WBCs
2-6x10^9/litre
normal number of platelets
150-400 x 10^9/litre
how often do you replace blood cells
RBCs = 120 days WBCs = 3-5 days platelets = 10 days
what are sites of haemopoiesis in embryos, children and adults
embryos = yolk sac
6 weeks-7months = liver and spleen
7months-adults = bone marrow
what are the 4 divisions that a CFU myeloid progenitor cell can turn into
BFU - RBC
CFUmeg - megakaryocyte
CFUgranulocyte - monocytes, neutrophils, eosinophils
CFUbaso - basophils
which two “end stage” blood cells are from the same precursor
monocytes and neutrophils
how do the precursor blood cells know when to leave the BM
changes in adhesion molecules
what is the important thing to remember about the haemopoietic growth factors
- the effects are mediated through specific receptors (different effects on different receptors)
- multiple GFs affect every part of the pathway (redundancy)
what are the important haematinics required for haemopoiesis
iron
vitamin B12
folate
what are the three “parts” of the RBC
membrane
Hb
enzymes
what is vitamin B12 important for
rapidly producing cells
what are the main reasons why we see vitamin B12 deficiency
dietary deficiency
poor absorption
metabolic pathway problem
what are the main reasons why we see folate deficiency
dietary deficiency
drugs
terms for low RBCs/WBCs and platelets (together and individually)
pancytopaenia = all anaemia = RBC leukopenia/neutropenia/lymphopaenia = WBC thrombocytopaenia = platelets
what are the terms for too many RBCs, WBCs and platelets
RBCs = polycythaemia WBCs = leukocytosis platelets = thrombocytosis
what are the terms for RBCs, WBCs and platelets not “working properly”
RBC = dyserthropoiesis WBC = white cell function defect platelet = platelet function defect
what is the definition of anaemia
a Hb level below that which is normal for age and gender
what is the REALLY IMPORTANT formula we have to know for haematology
tissue oxygen deliver = CO x Hb x %O2Sat x 1.34
what is the difference of the impact of anaemia in acute and chronic settings
acute = only able to compensate for a low Hb with increased HR chronic = able to also compensate with an increased SV
clinical signs of anaemia
- pale
- lethargic
- failure to thrive
- hypoxic
- ischaemia
- tachycardia
what are the 3 major causes of anaemia
failure of production
increased destruction/loss
inappropriate production
what are the signs of increased production of blood cells
reticulocytes
polychromasia
what are the signs of increased destruction of blood cells
jaundice
haptoglobins
LDH
what is the sign of haemolysis due to membrane dysfunction of the RBC
spherocytes
what are the signs of haemolysis due to enzyme dysfunction of the RBC
blister/bit cells
spherocytes
what is the sign of haemolysis due to dysfunction in the Hb
sickle cells
what are the causes of RBC membrane dysfunction causing haemolysis
hereditary spherocytosis
hereditary pyropoikilocytosis
what are the causes of RBC enzyme dysfunction causing haemolysis
G6PD - common
pyrovate kinase
what are the causes of RBC Hb dysfunction causing haemolysis
thalassemia
sickle cell
unstable Hb
what tests do you perform if you see spherocytes on a blood slide
E5M
what test do you perform if you see bite cells/blister cells on a blood slide
G6PD assay
what tests do you perform if you see sickle cells on a blood slide
Hb electrophoresis
HPLC
what are the 3 main causes external to the red cell that cause haemolysis
immune mediated
mechanical
infection
what is the most common cause of mechanical haemolysis
sepsis
what would you see on a blood slide with immune mediated haemolysis
spherocytes
agglutination
what would you see on a blood slide with mechanical mediated haemolysis
microangiopathic
what would you see on a blood slide with infection mediated haemolysis
parasites
what are the 3 major reasons for anaemia due to failure of production
haematinics
marrow failure/suppression
marrow invasion
what are the main things that cause microcytic anaemia
- blood loss
- iron deficiency
- thalassemia
what are the main things that cause macrocytic anaemia
vitamin B12 deficiency
folate deficiency
liver disease
drugs
what is the difference in information that you get via a bone marrow examination by aspirate or by trephine
aspirate = can see morphology of the cells trephine = can see the architecture of the bone marrow
which chromosome are the ABO genes located on
ABO = chromosome 9
H gene = chromosome 19
what is the association between the H substance and ABO
H substance is the precursor protein for ABO antigens. The bodys transferases convert the H antigen to the A, B antigens, or don’t convert it = O
ABO genes code for…
transferase enzymes which add sugars to H substance
what is the most important antigen for the rhesus blood group system
D
D = positive
no D = negative
what is the difference between the antibodies made for ABO or for Rh
ABO - naturally occurring Ab
Rh - antibodies only made after exposure
what are the antibodies made by different blood groups against ABO
A = Antib B B = anti A AB = no antibodies O = anti A and Anti B
which blood types can each blood group receive
A = A or O B = B or O AB = A or B or O or AB O = only O
