2: Macrocytic anaemia and macrocytosis Flashcards
What MCV defines macrocytosis
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What are the 3 types of macrocytosis
- Megaloblastic
- Non-Megaloblastic
- Other
What are 3 causes of megaloblastic macrocytosis
Vitamin B12 Deficiency
Folate Deficiency
Anti-Folate Medications
How long do vitamin B12 stores usually last
3-5 years
What condition can lead to vitamin B12 deficiency
Pernicious anaemia
How long do folate stores last
3-months
What are 4 anti-folate medications
Trimethoprim
Phenytoin
Methotrexate
Hydroxyurea
What are non-megaloblastic causes of macrocytic anaemia
Hypothyroidism Pregnancy Macrocytosis Reticulocytosis Liver Disease
What are 4 other causes of microcytic anaemia
- MDS
- MPD
- Myeloma
- Aplastic anaemia
Explain pathophysiology of macrocytic anaemia
- Macrocytosis is due to a defect in DNA production
- It is where cells do not have the correct number of DNA copies.
- In response cells keep increasing in size
- If too large cells will undergo intra-medullary haemolysis causing anaemia
- To compensate bone marrow increases cell production resulting in megalocytosis
- Megalocytosis also happens to other cells causing hyper-segmented neutrophil appearance
What is first-line in anaemia
FBC
What is looked at after FBC
Vitamin B12 and Folate
What is then looked at
Peripheral blood smear
What will be seen on peripheral blood smear
Hyper-segmented neutrophils if megaloblastic
When is a bone marrow biopsy indicated
If cause not identified by previous tests
How long does the body store folate for
3-months