lecture 13 - macrocytic anaemia Flashcards
What are the key causes of macrocytic anaemia?
Vitamin B12 deficiency, folate deficiency, liver disease, alcoholism, haemolysis causing increased reticulocytes
What is the most common type of macrocytic anaemia?
Megaloblastic anaemia
What are the 2 main causes of megaloblastic anaemia?
Vitamin B12 deficiency, Folate deficiency
Why do Vit B12 and foalte deficiencies cause megaloblastic anaemia?
Cause developing RBCs to have difficulties synthesising DNA, resulting in abnormal RBC maturation making them larger than normal (macrocytic)
Where is Vitamin B12 stored?
The liver
What are the most important causes of Vitamin B12 deficiency?
Pernicious anaemia (destruction of parietal cells that produce intrinsic factor), gastrectomy, poor dietary intake (e.g. vegan diet), resection of terminal ileum (reduced absoprtion)
What are the most serious complications of Vitamin B12 deficiency?
Neurological symptoms - neuropathy, sensory loss, cognitive impairment
Why are vegans at dramatically elevated risk of Vitamin B12 deficiency?
There are very few non-animal sources of Vitamin B12 (mostly found in dairy and meat)
What are the causes of folate deficiency?
Malabsorption, drugs, poor diet, pregnancy, dialysis
What is the treatment for Vitamin B12 deficiency?
Vitamin B12 injections
What is the treatment for folate deficiency?
Folic acid supplements (increase dose in cases of malabsorption)
Why does alcoholic liver disease cause macrocytic anaemia?
Affects RBC development in the bone marrow
Why can haemorrhage cause a resulting macrocytic anaemia?
Mass production of RBCs results in high concentration of reticulocytes (new red cells) which are larger than mature cells
What is the most common cause of macrocytic anaemia in the elderly?
Myelodysplastic syndrome
