Haemolytic anaemias Flashcards
What is haemolytic anaemia?
Reduced haemoglobin level for the age and gender of the individual due to shortened RBC survivability
How long do average RBCs survive for?
120 days
the body produces about 200 billion blood cells (2x10^11)
Why do RBCs contain no nuclei or cytoplasmic organelles?
So they can carry as much Hb as possible but also to be able to deform and travel through microcirculation (a RBC is about 8 microns wide and some parts they need to travel through are 3.5 microns wide).
How are senescent (Mature) RBCs removed?
the reticuloendothelial system (RES) found mainly in the liver and spleen
How short is RBC life in haemolytic anaemia?
30-80 (from 120)
How short is RBC life in haemolytic anaemia?
30-80 (from 120)
How does the bone marrow compensate for the decreased RBC life span?
It increases RBC production resulting in an increase in reticulocytes (reticulocytosis) and an increase in nucleated RBCs as well
What happens if RBC production is able to keep up with the RBC destruction?
Compensated haemolysis where Hb level will stay normal but the life span of an RBC will still be decreased
What happens if RBC production is NOT able to keep up with the RBC destruction?
Incompletely compensated haemolysis which results in a decrease in Hb
What are the clinical presentations of haemolytic anaemia?
Jaundice- Hb is broken down into heme, heme is then further broken down into protoporphyrin which is then also broken down into bilirubin (bilirubin in excess causes jaundice) [heme->protoporphyrin->bilirubin]
Pallor
Fatigue
Splenomegaly (spleen enlargement)
Chronic findings:
Gallstones (caused by bilirubin)
folate deficiency (inc RBC production)
leg ulcers due to ischemia (blood flow and thus oxygen is restricted or reduced in a part of the body)
What is bilirubin and what is it used for?
Bilirubin is a by-product of the body recycling RBCs, when the RBCs are broken down and bilirubin is produced, the liver uses it to make bile.
What is Urobilinogen?
This is the substance that is made when bilirubin is broken down in the intestines
What do peripheral blood films for haemolytic patients show?
Polychromatophilia (extra staining on RBCs due to increase RNA content from immature RBCs)
Nucleated RBCs (compensating for the decreased life span by creating more RBCs than usual)
thrombocytosis
neutrophilia with left shift (more immature neutrophil production because of the RBC production)
What are morphologic abnormalities seen on peripheral blood films in haemolytic patients?
Spherocytes- (sphere shaped rbcs)
Sickle cells- (crescent shaped cells)
Target cells- (a cell with a dark ring of haemoglobin in the centre surrounded by an area of pallor and then an outer ring of haemoglobin again, looks like a bulls eye or archer target hence the target cell name)
Schistocytes- (Triangular fragmented RBCs)
Acanthocytes- (dense, shrunken, and irregularly shaped red blood cells with spikes on the outside)
What are morphologic abnormalities seen on peripheral blood films in haemolytic patients?
Spherocytes- (sphere shaped rbcs)
Sickle cells- (crescent shaped cells)
Target cells- (a cell with a dark ring of haemoglobin in the centre surrounded by an area of pallor and then an outer ring of haemoglobin again, looks like a bulls eye or archer target hence the target cell name)
Schistocytes- (Triangular fragmented RBCs)
Acanthocytes- (dense, shrunken, and irregularly shaped red blood cells with spikes on the outside)
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