Anaemias Flashcards
What does optimal cell production require?
Iron, vitamin B12, Folate
Outline a folic acid deficiency (Vit. B9)
Often due to poor diet, cancer, anti seizure drugs.
Diagnosed by low levels of folate, megaloblasts.
Treat by food and supplements.
What is a vitamin B6 deficiency associated with?
Microcytic anaemia
What is pernicious anaemia a deficiency of?
B12
How is pernicious anaemia diagnosed?
Megaloblasts, abnormal bone marrow precursors, antibodies to intrinsic factor, a gastric analysis
What causes pernicious anaemia?
A failure to secrete intrinsic factor, meaning B12 cannot bind to it and enter the blood stream.
What is ferritin?
An intracellular protein store for iron
Apoferritin hinds free ferrous iron to store in ferric state (Fe³+)
How does an iron overload present?
Organ dysfunction (due to iron deposition)
Congestive heart failure
Liver haemosiderosis and cirrhosis
Excessive melanin pigmentation
How is iron overload treated?
Venesection (blood removal)
Iron chelation using sub-cutaneous desferrioxamine
Vitamin C to enhance iron excretion
What anemia can be caused by iron overload?
Sideroblastic anemia - iron cannot be added to haemoglobin
What is thalassemias?
A quantitative disorder
Defect in amount of globin, reduced alpha and/or beta chains
Poor oxygen transport
Defect in production
Requires regular blood transfusions
Compare alpha and beta thalassemias
Alpha = chromosome 16, 4 alpha globin genes. Majority of mutations are deletions. Both or one gene malfunction. Silent carriers (if only one is deletion has no effect)
Beta = Chromosome 11, two beta globin genes. 200 different mutations. Can result in reduction to abolition of B globin function.
What is the most serious type of malaria in humans?
Plasmodium falciparum
Causes majority of deaths
Compare free alpha vs free beta chains
Free alpha are toxic
Free beta are stable, but useless
