Iron, B12, folate deficiency Flashcards
What are the general symptoms of anaemia?
Fatigue, dizziness, headache, SoB, palpitations, angina, pallor, intermittent claudication, tachycardia, flow murmur, congestive cardiac failure
What are symptoms of anaemia that are more specific for iron deficiency?
Glossitis, koilonychia, angular stomatitis, alopecia, picca (e.g. ice)
What are the broad causes for iron deficiency anaemia?
Reduced intake, reduced absorption, blood loss, increased iron requirement
What abnormality is suspicious in a man or post menopausal woman?
Iron deficiency anaemia, suspicious of chronic GI bleed
At what level will symptoms be present in iron deficiency anaemia?
<8g/dL
What are the investigation findings in iron deficiency anaemia?
Microcytic, hypochromic anaemia Reduced serum iron and ferritin Increased serum transferrin and TIBC Reduced plasma transferrin saturation Absence of iron stores on bone marrow smear
How should iron deficiency be treated?
Treat underlying
Ferrous sulphate for 4-6 months
Parenteral Fe if absorption is the issue
What are the side effects of iron treatment?
Diarrhoea, constipation, dark faeces
Who does anaemia of chronic disease commonly affect?
Elderly and hospital inpatients
What is the pathogenesis of anaemia of chronic disease?
Activated macrophages are erythropagocytic and secrete cytokines e.g. TNF
Activation of macrophages leads to decreased erythropoiesis and RBC lifespan
What are the FBC findings for anaemia of chronic disease?
Can be normocytic, microcytic
Normochromic, hypochromic in a third
How can you differentiate Fe deficiency and anaemia of chronic disease?
If MCV is very low (<70) Fe is more likely
Fe: low serum Fe, low ferritin, high/normal transferrin, high expression transferrin receptors
Chronic disease: low serum Fe, high/normal ferritin, low/normal transferrin, low/normal transferrin receptor expression
Apart from Fe deficiency and anaemia of chronic disease what are other causes of microcytic anaemia?
Sideroblastic anaemia
Thalassaemia
Lead poisoning
What is sideroblastic anaemia?
Refractory anaemia, increased bone marrow iron
Presence of ringed sideroblasts, which are red-cell precursors containing iron granules surrounding the nucleus
Why does lead poisoning cause anaemia? What are the other symptoms?
Inhibits haem and globin synthesis
Abdominal pain and neuropathies
What is B12 composed of?
Cobalamin bound to methyl or adenosyl group
How is B12 transported and absorbed?
Intrinsic factor secreted by gastric parietal cells binds to B12 to prevent HCl degradation
Absorption occurs in the terminal ileum
Transported by plasma protein transcobalamin II
Where is B12 stored? How long does it take to become deficient?
In the liver
Approx 2 years
What are the causes of B12 deficiency?
Diet (e.g. vegan), low IF (pernicious, gastrectomy, congenital), malabsorption (Crohn’s), blind loop/diverticulae of small bowel (breed bacteria that uses vitamin B12)
What is pernicious anaemia also known as?
Autoimmune chronic atrophic gastritis
What causes pernicious anaemia?
Auto antibodies against gastric parietal cells in serum and gastric juice
What clinical feature accompanies pernicious anaemia as a result of destruction of parietal cells?
Achlorhydria (parietal cells secrete H+)
What other conditions is pernicious anaemia associated with?
AI thyroid, increased risk gastric carcinoma
What are the signs and symptoms of pernicious anaemia?
Lemon-yellow skin, glossitis, GI disturbances, psychiatric disturbance
Neuro: peripheral neuropathy, subacute degeneration of the cord
What is the treatment of pernicious anaemia?
Correct B12 with IM B12 injections every 3 months
Where is folate absorbed?
Duodenum, jejunum
What are the causes of folate deficiency?
Reduced intake (poor diet), increased loss (dialysis), drugs (EtOH, trimethoprim, methotrexate, anticonvulsants), increased cell turnover (pregnancy, prematurity, malignancy, haemolytic anaemia)
How do you differentiate between B12 and folate deficiency?
Measure serum folate
