Haem - Anaemia, IDA, B12+pernicious anaemia, Thalassaemia Flashcards
Anaemia - what is the definition of anaemia?
Defined as low level of Haemoglobin in the blood
Anaemia - what is mean cell volume?
This is the size of the RBCs
Anaemia - what are the three categories MCV can be divided into?
Microcytic anaemia - low MCV, small RBCs
Normocytic anaemia - normal MCV, normal sized RBCs
Macrocytic anaemia - high MCV, large RBCs
Anaemia - what are microcytic anaemia causes?
TAILS
Thalassaemia
Anaemia of chronic disease
Iron Deficiency Anaemia
Lead poisoning
Sideroblastic anaemia
Anaemia - what are normocytic anaemia causes?
AAAHH or AHAHA
Acute blood loss
Anaemia of chronic disease
Aplastic anaemia
Hypothyroidism
Haemolytic anaemia
Anaemia - what two categories can macrocytic anaemia causes be divided into and what are the causes?
Megaloblastic anaemia - impaired DNA synthesis, prevents cell from dividing normally, so cell grows into larger abnormal cell, caused by VITAMIN DEFICIENCY:
- B12 deficiency
- Folate deficiency
Normoblastic macrocytic anaemia:
- Alcohol
- Reticulocytosis
- Hypothyroidism
- Liver disease
- Drugs - azathioprine
Anaemia - what are the symptoms?
Fatigue
SoB
Palpitations
Headaches
Dizziness
Worsening of other conditions
Anaemia - what are some signs?
Pale skin
Conjunctival pallor
Tachycardia
Increased resp rate
Iron Deficiency Anaemia (IDA) - what are some reasons as to why a patient may become iron deficient?
- Insufficient dietary iron
- Iron requirements increase (pregnancy)
- Iron being lost (bleeding, menorrhagia)
- Malabsorption
IDA - where is iorn mainly absorbed?
Duodenum and Jejunum
IDA - what medications reduce stomach acid, and why is this a problem in IDA?
PPIs
Duo and Jej need soluble form of iron to absorb, which requires stomach acid to stay in that soluble form, but PPIs reduce stomach acid, so it changes to Fe3+ insoluble form, so interferes with Fe absorption
IDA - what is transferrin?
Carrier protein that binds iron
IDA - what is total iron binding capacity (TIBC)?
Total space on the transferrin molecule for the iron to bind
IDA - what is transferrin saturation, and what is the equation?
Proportion of transferrin molecules that are bound to iron
Transferrin Saturation = Serum iron / TIBC
IDA - what is ferritin?
Ferritin is the form iron takes when it is deposited and stored in cells
If serum ferritin low, highly suggestive of IDA
IDA - what would you see on blood results?
Increased TIBC
Increased transferrin
Decreased transferrin saturation
Decreased Ferritin
Decreased serum iron
IDA - what would you see on a blood film?
Poikilocytes - abnormally shaped RBCs
IDA - management?
PO ferrous sulphate/fumarate, 200mg TDS:
Give Vit C to aid absorption
Can take 3-6 months
SE - N+V, black stools
UNSUITABLE when MALABSORPTION is cause
IV iron:
Quickly corrects ID
Avoided during sepsis, as iron ‘feeds’ bacteria
B12 deficiency and Pernicious anaemia - what is it?
Pernicious anaemia is a cause of B12 (cobalamin) deficiency
B12 deficiency can be caused by insufficient diet of B12 or pernicious anaemia
B12 deficiency and Pernicious anaemia - function of B12?
B12 and folate aid DNA synthesis
B12 aids myselin formation
B12 deficiency and Pernicious anaemia - pathophysiology of B12 absorption
- Gastric parietal cells produce protein called intrinsic factor (IF)
- B12 binds to IF, B12-IF complex can then be absorbed in terminal ileum
B12 deficiency and Pernicious anaemia - what is pernicious anaemia?
Autoimmune condition where antibodies destroy gastric parietal cells or IF itself
Lack of IF prevents absorption of vitamin B12
B12 deficiency and Pernicious anaemia - what are the investigations and results?
1st line: IF antibody test
Bloods
FBC:
- Decresased Hb
- Increased MCV (as megaloblastic anaemia)
Decreased serum cobalamin
B12 deficiency and Pernicious anaemia - what is the management?
1st line if problem is absorption - Hydroxycobalamin IM, 3 times weekly for 2 weeks, then every 3 months
1st line if dietary deficiency - cyanocobalamin
Thalassaemia - what is it?
Alpha and Beta Thalassaemia are autosomal recessive disorders, which are cuased by a mutation that leads to dysfunction of either the alpha-globin or beta-globin chains on the Hb molecule
Thalassaemia - pathophysiology
- In thalassaemia, blood cells more fragile
- Break down more easily
- Spleen acts as a sieve to filter RBCs and remove RBCs
- In thalassaemia, spleen collects destroyed RBCs and swells - splenomegaly
- Bone marrow expands to produce more RBCs to compensate for anaemia, causes pronounced forehead and malar eminences
Thalassaemia - signs and symptoms
- Microcytic anaemia
- Pallor
- Jaundice
- Gallstones
- Splenomegaly
- Pronounced head and eminences
- Poor growth
Thalassaemia - investigations
FBC - Microcytic anaemia
Haemoglobin electrophoresis
DNA testing
Thalassaemia - what can occur in thalassaemia in response to anaemia?
Iron overload
Thalassaemia - why does iron overload occur, and what is the management?
Faulty creation of RBCs
Recurrent transfusions
Increased absorption of iron in response to anaemia
Management - limit transfusions, iron chelation
Thalassaemia - alpha thalassaemia causes what impairment?
Alpha thalassaemia leads to impaired oxygen transport extravascular haemolysis
Thalassaemia - beta thalassameia causes what abnormality?
Leads to failed erythropoiesis
Build up of alpha chains causing cell destruction
Compensatory erythroid hyperplasia causes bone growth
Thalassaemia - investigations
Bloods:
Decreased Hb
Decreased MCV
RBCs may be normal or high
Increased reticulocytes
Diagnosis: HB electrophoresis
Liver biopsy if iron overload
B12 deficiency and Pernicious anaemia - what is the presentation?
Megaloblastic anaemia
- Neurological symptoms - peripheral neuropathy with numbness or paraesthesia, impaired cognition, psychosis, impaired proprioception
- Glossitis
- Angular cheilitis
B12 deficiency and Pernicious anaemia - what are some causes?
Impaired absorption - crohn’s, ileal resection
Diet - vegan diet, malnutrition
Drugs - PPIs, metformin, alcohol
IDA - what are the soluble and insoluble forms of iron?
Soluble: Ferrous Fe2+
Stomach acid required to keep iron in soluble form, if acid levels drop, it changes to insoluble form Ferric Fe3+
Anaemia - what two categories can macrocytic anaemia causes be divided into and what are the causes?
Megaloblastic anaemia - impaired DNA synthesis, prevents cell from dividing normally, so cell grows into larger abnormal cell, caused by VITAMIN DEFICIENCY:
- B12 deficiency
- Folate deficiency
Normoblastic macrocytic anaemia:
- Alcohol
- Reticulocytosis
- Hypothyroidism
- Liver disease
- Drugs - azathioprine