Flashcards in Anaemia Deck (70):
A red cell that is larger than average with RNA remnants?
Reticulocyte - immature red blood celll
How long does the up regulation of reticulocyte production take in response to anaemia?
1 -2 days (there may also be a transient initial response)
What type of anaemia do you get in iron deficiency?
In what two situations might Haemoglobin/Haematocrit not be good markers of anaemia?
What two things can cause loss/destruction of red blood cells?
What two things can cause a decreased production of RBCs?
Reduced amount of erythropoiesis
Maturation abnormality - erythropoises present but ineffective
(Cytoplasmic defects causing impaired haemoglobinisation or nuclear defects causing impaired cell division
What cell parameter is most useful for deciding whether or not your anaemia is caused by increased loss or decreased production of RBCs?
What do cytoplasmic defects of erythropoesis result in?
What do nuclear defects of erythropoesis result in?
Impaired cell division
If the MCV is low what kind of anaemia is it?
If MCV is high what kind of anaemia is it?
If there is a problem with haemoglobinisation what kind of anaemia will you have/?
If there is a problem with maturation what kind of anaemia will you have?
Where is haemoglobin synthesised?
What causes hypochromic, microcytic anaemia?
Deficient haemoglobin synthesis = cytoplasmic defect
What is the most common underlying cause of hypochromic microcytic anaemia?
Aside from iron deficieny what is the other large cause of hypochromic microcytic anaemia?
What is thalassaemia?
Deficiency of globin
What two states can iron exist in?
How many oxygen molecules can bind to a haem group?
What molecule is iron stored as?
What molecule is iron transferred as?
What is transferrin?
A protein with two binding sites for iron atoms
What does transferrin do?
Transports iron from donor tissues (macrophages, intestinal cells and hepatocytes) to tissues expresssing transferring receptors (especially in erythroid marrow)
What would transferrin levels be reduced?
Anaemia of chronic disease
What would transferrin levels be increased?
What do low ferritin levels mean?
What is serum ferritin a measure of?
What is a megaloblast?
An abnormally large nucleus cell precursor
What happens in megaloblastic anaemia?
Defects in DNA synthesis and nuclear maturation with relative preservation of RNA and hameoglobin synthesis
What does free B12 bind to first in the stomach?
What does B12 bind to after it is released from haptocorrin?
Where is B12 absorbed?
Where is folate absorbed?
If you stopped consuming B12 how long would it take for you to become deficient?
2 - 4years
If you stopped consuming folate how long would it take for you to become deficient?
How much folate do you need a day?
How much B12 do you need a day?
1 - 3ug
What problems are particular to Vitamin B12 deficiency?
Neurological deficiency due destruction of the myelin dheath
Why is the cell large in megaloblastic anaemia?
There is failure of the cell to get smaller
What is pernicious anaemia?
Autoimmune condition with resulting destruction of gastric parietal cells
What other conditions is pernicious anaemia particularly associated with?
What is the blood film like in patient with B12 or folate deficiency?
Macrocytes - oval
Abnormal nuclear segmentation of the neutrophils (greater than 5 segments?
What auto antibodies are you looking for in pernicious anaemia?
Anti - gastric parietal cell antibodies
Anti intrinsic factor
What signs on examination would be looking for in anaemia?
High flow murmur
Dysphagia (very rarely)
Where is the main sight of iron absorption in the the body?
What is the cause of anaemia?
Iron deficient anaemia
What are the problems with ferritin measurement?
Ferritn is an acute phase protein so will be raised in inflammation and maligancy
What would you be looking for on a blood film on someone with iron deficient anaemia?
Variation in cell size and shape
What abnormality would you expect to see in the neutrophils of a patient with macrocytic anaemia due to B12 deficiency?
Hypersegmented nucleus - greater than 6 lobes to the nucleus
(leucopenia will be seen in severe cases)
What abnormality would you expect to see in the platelets of a patient with macrocytic anaemia due to B12 deficiency?
Describe the process of absorption of Vitamin B12:
- Vitamin B 12 absorbed in the stomach
- Then they bind to intrinsic factor which is produced by parietal cells.
- This complex then travels through intestine to be absorbed by the terminal ileum.
Where is vitamin B12 absorbed?
In what two parts of the digestive system could a problem lead to B12 deficiency?
A man has crohn's disease affecting his ileo - caecal junction. Which vitamin is he most likely to be deficient in?
A women has has a gastrectomy due to gastric cancer. What vitamin is she most likely to be deficient in?
What cells are attacked in pernicious anaemia?
What is the treatment for B12 deficiency?
Hydroxycobalamin IM every three months
(At the start of treatments a high dose will be given over three weeks as a loading dose)
What is the danger of starting someonw on folate without checking their B12?
If their B12 is low and you give them folate you can precipitate neurological problems and cause demyelination of the spinal cord.
What drugs have anti folate actions?
Some anti convulsants
What is the diagnostic test for B12 deficiency?
What is the diagnostic test for folate deficiency?
Red cell folate
What is the treatment of folic acid deficiency?
Folic acid oral tablets
What is the mechanism of anaemia of chronic disease?
In response to inflammatory cytokines (mostly IL 6) the liver produces increased amounts of hepcidin.
Hepcidin then causes increased internalisation of ferroportin molecules on cell membranes which prevents release of iron from stores.
This also blunts erythopoiesis by decreasing the ability of the bone marrow to respond to EPO
Why might the ferritin be high in anaemia of chronic disease?
It is an acute phase protein - responds to inflammation.
What is myelodysplasia?
Mild malignancy of early myeloid progenitor cells mostly seen in the elderly.
What is aplastic anaemia?
A deficiency of all types of blood cell caused by failure of bone marrow development.
In what kind of conditions do you get normochromic, normocytic anaemia?
In hypoproliferative anaemic conditions....
Chronic inflammatory, infective and malignant conditions
Hypometabolic states such as hypothyroid
What test on he FBC gives information about whether the anaemia is hypochromic or normochromic?
Mean Cell Haemaglobin (MCH)