Macrocytic anaemias Flashcards
What can cause Folate deficiency?
Decreased intake - dietary
Increased demands - pregnancy, haemolysis, malignancy
Malabsorption - Coeliac’s, Crohn’s
Drugs - Phenytoin, Methotrexate, ethanol
How can you manage Folate deficiency?
Assess for underlying cause + treat it
Give B12 first unless B12 level known to be normal (May precipitate or worsen SubAcute Combined Degeneration of spinal cord)
Folate 5mg/d PO
Where is folate absorbed in the GI tract?
Proximal jejunum
Stored for 4 months
What is the dietary sources of folate?
Green vegetables
Nuts
Liver
What is the dietary source of B12?
Fish
Meat
Dairy
Where is B12 absorbed?
Terminal ileum bound to intrinsic factor
Where is intrinsic factor secreted?
Parietal cells in stomach
What is the role of B12?
DNA synthesis
Myelin synthesis
What are the causes of low B12?
Decreased intake - Dietary eg began
Decreased absorption due to issues with terminal ileum - Crohn’s, Coeliac’s, Ileal resection, bacterial overgrowth
Decreased intrinsic factor - Pernicious anaemia, post gastrectomy
What are the features of B12 deficiency?
Malaise
Glossitis
Lemon tinge - mild jaundice + pallor
Neuro - Parasthesia, Peripheral neuropathy, Optic atrophy, subacute combined degeneration of the spinal cord (Posterior column)
What is Subacute Combined Degeneration of the Cord ?
Combined symmetrical loss of dorsal column and corticospinal tracts
→ distal sensory loss: esp. joint position and vibration
→ ataxia with wide-gait and +ve Romberg’s test
Get mixed UMN and LMN signs
Pain + temperature remain intact!
What is Pernicious anaemia?
Autoimmune atrophic gastritis caused by autoAntibodies against parietal cells or IF
Associated with other autoimmune conditions and a 3x increased risk of gastric adenocarcinoma
