3: Anaemia and microcytic anaemia Flashcards
What does anaemia mean?
Without blood
> Reduced total red cell mass
What measurements are used to diagnose anaemia?
Haemoglobin concentration or Haematocrit
because you can’t actually measure red cell mass
What is haematocrit?
Volume of red blood cells / Blood volume
In what situations can anaemia be mistakenly diagnosed?
Rapid bleeding
Rapid plasma expansion (e.g fluids)
because the total blood volume changes, not the red cell volume
What happens to the rate of red blood cell production in anaemia?
Increases
What is an increase in immature red cell number called?
Reticulocytosis
What is an immature red blood cell called?
Reticulocyte
What process occurs in the bone marrow in anaemia?
Reticulocytosis
What tool is used to get a FBC, MCV, red/white cell number etc?
Automated cell counter
Reticulocytes still have residual RNA.
What colour does this RNA turn on a blood film?
“Polychromatic”
Blue-grey
What are three measurements given by an automated cell counter re: RBCs?
Haemoglobin concentration
Red cell count
Mean cell volume (MCV)
What are the two main causes of anaemia?
Increased RBC loss
Decreased RBC production
What should happen to cell size as progenitor red blood cells divide?
Cell size should decrease
Microcytic anaemia is caused by a problem with ___ synthesis.
haemoglobin synthesis
What size are red blood cells in anaemia caused by decreased haemoglobin synthesis?
Small
Microcytic anaemia
What is the most common cause of microcytic anaemia?
Iron deficiency
Iron deficiency is the most common reason for microcytic anaemia.
What is a deficiency of globins called?
Thalassaemia
another common reason for microcytic anaemia
Where is most body iron found?
RBCs
rest in macrophages, liver, bone marrow
In what form is iron stored in the liver?
Ferritin
Which transport protein takes iron from the blood to macrophages in the bone marrow?
Transferrin
Which cells transfer iron to red blood cells in the bone marrow?
Bone marrow macrophages
In what forms is iron
a) functioning in the body
b) transported in the circulation
c) stored in the liver?
a) Haemoglobin
b) Transferrin
c) Ferritin
What two measurements show that a patient has iron deficiency?
Low storage ferritin
Low haemoglobin (functional iron)
What are three causes of iron deficiency?
Inadequate iron intake
Malabsorption
Blood loss
(Men / Women) are more likely to be iron deficient.
Women
Men tend to have greater iron intakes
From which part of the GI tract is iron absorbed?
Proximal jejunum
Which autoimmune condition affects the proximal jejunum and can therefore cause iron deficiency?
Coeliac disease
What are some chronic causes of blood loss which might cause an iron deficiency?
GI - peptic ulcers, H pylori, insidious tumours
Gynae - menorrhagia
Renal - haematuria (AKI)
What are some clinical signs of iron deficiency?
Koilonychia
Angular stomatitis
Glossitis
Iron deficiency causes a (microcytic / macrocytic) anaemia.
microcytic
because the problem is with hb synthesis in the cytoplasm, not nucleus
What is iron’s main transport protein?
Transferrin
In which cells is haemoglobin synthesised?
Immature red blood cells
To which part of immature red blood cells is iron transported for haemoglobin synthesis?
Mitochondrion
Fe2+ + ___ => Haem
Fe<strong>2</strong>+ + Porphyrin ring => Haem
Haem + ___ => Haemoglobin
Globins
Where is
a) haem
b) haemoglobin
made?
a) Mitochondria of immature RBCs
b) Cytoplasm of immature RBCs
What are the two most common causes of microcytic anaemia?
Iron deficiency
Thalassaemia
