Hyperchromic, Macrocytic anaemia Flashcards
If someone had macrocytosis, what investigations would you do?
- B12/Folate Assay
- LFTs, TFTs
- Blood Film
- Bone Marrow biopsy
What are causes of hyperchromic, macrocytic anaemia?
- B12/Folate Deficiency
- Alcohol excess/liver disease
- Reticulocytosis
- Cytotoxics
- Myelodysplastic syndromes
- Marrow infiltration/Myeloma
- Hypothyroidism
- Myeloproliferative disorder
- Aplastic anaemia
- Anti-folate drugs (e.g phenytoin)
What signs might be seen in pernicious anaemia and anaemia caused by B12 deficiency?
- Lemon-yellow skin colour
- Glossitis
- Angular stomatitis
- Vitiligo
- Jaundice
- Paraesthesiae
- Peripheral Neuropathy
- Neuropsychiatric problems
When is bone marrow biopsy indicated in macrocytic anaemia?
Indicated for when blood tests don’t reveal a cause
What can bone biopsy show in macrocytic anaemia?
- Megaloblastic anaemia
- Non-Megaloblastic anaemia
- Abnormal erythropoeisis
- Increased erythropoeisis
What are megaloblasts?
Erythroblasts with delayed nuclear maturation because of defective DNA synthesis (megaloblasts). Megaloblasts are large and have large immature nuclei. The nuclear chromatin is more finely dispersed than normal and has an open stippled appearance.
What are sources of folate?
- Green vegetables
- Nuts
- Yeast
- Liver
How long do body stores of folate last?
4 months
Where is folate absorbed?
Duodenum/proximal jejunum
What are causes of folate deficiency?
- Poor diet - poverty, alcohol, elderly
- Increased demand - pregnancy/increased cell turnover
- Malabsorption - coeliac disease, tropical sprue
- Drugs - anti-epileptics, methotrexate, trimethoprim
How would you manage someone with folate deficiency?
- Treat the cause
- Oral folate replacement
- Ensure B12 normal if neuropathic symptoms
What dose of folic acid would you treat someone with for folate deficiency?
5mg/day - 4 months
NEVER WITHOUT B12 - unless patient is known to have normal B12
What is subacute degeneration of the spinal cord?
Degeneration of the posterior and lateral columns of the spinal cord as a result of vitamin B12 deficiency. It is usually associated with pernicious anemia.
Why does someone with B12 deficiency have a lemon yellow tinge?
Combination of anaemia and jaundice
What are the most common causes of B12 deficiency?
- Dietary
- Malabsorption
- Congenital metabolic errors
What are malabsorptive problems that can lead to B12 deficiency?
- Stomach - Pernicious anaemia, post gastrectomy
- Terminal Ileum - Ileal resection, Crohn’s disease, bacterial overgrowth, tropical sprue, tapeworms
What is pernicious anaemia?
An autoimmune disorder in which there is atrophic gastritis with loss of parietal cells in the gastric mucosa with consequent failure of intrinsic factor production and vitamin B12 malabsorption.
What age does pernicious anaemia occur most commonly in?
Elderly
How long do signs/symtpoms take to develop in pernicious anaemia?
1-2 years
What investigations would you do for someone with suspected pernicious anaemia?
- Bloods - FBC, MCV, Serum B12, Reticulocyte
- Blood Film
- Bone marrow
- Parietal cell/intrinsic factor antibodies
How would you manage someone with B12 deficiency?
If malabsorption, B12 injections:
- Hydroxocobalamin - 1mg IM injection alternate days for 2 weeks, then 1mg injections every 3 months
If dietary, then oral B12
What neurological problems can occur in B12 deficiency?
- Paraesthesiae
- Peripheral neuropathy
- Subacute degeneration of the spinal cord
What are neuropsychiatric features of B12 deficiency?
- Irritability
- Depression
- Psychosis
- Dementia
What are features of subacute combined degeneration of the spinal cord?
Symmetrical Peipheral Sensory neuropathy + UMN + LMN signs
- Classic triad - extensor plantars, absent knee jerks, absent ankle jerks
- Preserved pain and temperature - spinothalamic tracts preserved
- Ataxia - due to loss of proprioception
- Stiffness and weakness - tend to follow ataxia
What tracts are commonly affected in subacute combined degeneration of the spinal cord?
Dorsal columns and corticospinal tracts
What is often the first thing to go in subacute combined degeneration of the spinal cord?
Proprioception and vibration
