Medicine - Haematology Flashcards
(122 cards)
Define anaemia
Low RBC’s / reduced O2 carrying capacity of RBC’s -> leads to not enough O2 in the blood to meet the body’s physiological demands
Hb <130g/L (M) or <120g/L (F)
Define the aetiologies of anaemia
- increased cell loss (bleeding, hypersplenism, haemolysis)
- reduced/ineffective production (malignancy, myelodysplasia, folate/B12/ferritin deficiencies, renal failure (low EPO), ACD (high hepcidin))
What is the role of hepcidin?
Produced by the liver
Controls movement of iron from the gut -> blood
What are the two storage forms of iron?
Old RBC’s are eaten by macrophages in the RES and then the iron is stored as
1) ferritin (soluble)
2) haemosiderin (insoluble)
What are signs and symptoms of anaemia?
SOB palpitations chest pain pale cravings faint/dizzy pale mucous membranes koilonychia tachynoea oedema angular stomatitis/glossitis
What investigations should be carried out to investigate anaemia?
- FBC (Hb, RBC, WCC)
- MCV
- Haematinics (B12, plasma ferritin, plasma folate)
- Iron studies: serum iron, Tf saturation, TIBC
Describe iron deficiency anaemia and its causes
Hypochromic microcytic anaemia Tf saturation <15% Causes: - dietary (low iron) - blood loss (menorrhagia, bleeding) - malabsorption (coeliac disease)
What might be seen on the blood film of a patient with iron deficiency anaemia?
Poikilocytes (abnormally shaped RBC’s can be due to low vit B12)
In a patient with iron deficiency anaemia, what abnormalities in the following blood tests might be seen?
- Serum iron
- Serum ferritin
- TIBC
- MCV
- MCH
- low
- low
- high
- low
- low
Define anaemia of chronic disease and its causes:
Normochromic, normocytic anaemia
Failure of iron utilisation, as it is trapped in the RES
? thought to be due to increased hepcidin (as this protein controls iron movement from the gut into the blood)
Causes:
- infection
- renal failure
- malignancy
- inflammatory conditions e.g. arthritis, IBD (the severity of the anaemia correlates with the severity of the disease)
What would a blood film in ACD show?
Rouleux (stacks of RBC’s)
Describe the following blood results in a patient with ACD:
- serum iron
- serum ferritin
- TIBC
- low
- high/normal
- low (bound to ferritin)
Describe the treatment of ACD
Treat the underlying cause (anaemia will not respond to iron replacement)
- ?EPO
- ?hepcidin inhibitors
- .?transfusion (beware of iron overload)
Define sideroblastic anaemia, its causes and how it may present (in addition to normal anaemia symptoms)
- Ineffective erythropoiesis
- Sideroblasts produced
- Causes increased Fe absorption and haemosiderin accumulation -> think of sideroblastic anaemia when microcytic anaemia is not responding to iron
Causes: - congenital
- acquired (chemotherpay, MPD)
Will present with organomegaly (XS RBC destruction) and organ failure as iron accumulates in heart, kidneys, and liver
What would the blood film and bone marrow look like in a patient with sideroblastic anaemia
Film: HYPOCHROMIC micro/normo/macrocytic anaemia
Bone marrow: sideroblasts will be seen (nucleated erythrocytes with iron granules)
What would the following blood results be like in a patient with sideroblastic anaemia?
- Serum iron
- Serum ferritin
- TIBC
- high
- high
3.
How is sideroblastic anaemia treated?
Treat the cause:
- alcohol cessation
- pyridoxine replacement (vit B6)
- transfusions
Describe megaloblastic anaemia and its causes
- megaloblastic anaemias are a group of conditions which are due to folate/B12 deficiencies leading to a reduced no. RBC’s which are very large
- delayed maturation of RBC nucleus relative to cytoplasm
Causes: low B12/ferritin due to -> - deficiencies
- pernicious anaemia (antibodies against IF)
- coeliac disease (malabsorption)
- gastritis (malabsorption)
What would BR and LDH measurements be like in megaloblastic anaemia?
High BR, high LDH
What important questions should you ask a patient with megaloblastic anaemia?
DIET! vegetarian vegan coeliac dietary deficiencies
What would the following blood results be in megaloblastic anaemia?
- MCV
- haematocrit
- reticulocytes
- B12/folate
- anti-parietal cell antibody
- high
- low
- low
- low
- may be present if pernicious anaemia
What would a blood film/smear of megaloblastic anaemia show?
Hypersegmented neutrophils
Megaloblastic (big) RBC’s
When treating megaloblastic anaemia, why should B12 be replaced before folate?
Can cause subacute combined degeneration of the spinal cord
Compare intra/extravascular haemolysis and their features
Intravascular -> in the circulation, raised free Hb in the plasma, may present with red/brown urine (haemoglobinuria)
Extravascular -> in the RES, causes splenomegaly