MACROCYTIC ANAEMIA Flashcards
What type of macrocytic anaemia does folate or B12 deficiency cause?
Megaloblastic anaemia (right shift)
What processes are affected by folate or B12 deficiency?
DNA synthesis
Where is vitamin B12 absorbed?
Ileum
What must be present for vitamin B12 to be absorbed?
Intrinsic factor
Which cells excrete intrinsic factor?
Parietal cells of the stomach.
What is the most common cause of vitamin B12 deficiency in the UK?
Pernicious anaemia
What is the underlying mechanism of pernicious anaemia?
Autoimmune gastritis where autoantibodies attack the parietal cells leading to a reduction in intrinsic factor.
Is pernicious anaemia more common in males or females?
Females
What is the peak age of onset for pernicious anaemia?
60
What diseases are associated with pernicious anaemia?
Vitiligo - patchy whiteness of the skin
Myxoedema
Hashimoto’s disease
Addison’s disease
Hypoparathyroidism
Where is folate absorbed in the intestine?
Upper small intestine
What disease is especially associated with folate deficiency?
Coeliac disease
What are the clinical features of megaloblastic anaemia caused by a vitaman B12 or folate deficiency?
Pallor
Jaundice
Gradual onset
May present with signs of congestive heart failure
What does the blood film of someone with anaemia related to vitamin B12 or folate deficiency look like?
Oval macrocytes
Hypersegmented neutrophil neuclei
Low white cell or platelet count
What are the characteristics bone marrow features of megaloblastic anaemia?
Megaloblastic erythroblasts
Giant metamyelocytes