Haematology Flashcards
(248 cards)
Define anaemia
Anaemia describes a low haemoglobin concentration due to either a reduction in the proportion of circulating red blood cells or increased plasma volume (pregnancy).
Give 3 mechanisms in which anaemia can be caused by
Blood loss (acute or chronic)
Haemolytic anaemia
Deficient/defective erythropoiesis
Define MCV
Mean Cell Volume - Describes the average size of red blood cells in a sample
Define MCH
Mean Corpuscular Haemoglobin - Describes the average quantity of haemoglobin present in a single red blood cell
Define MCHC
Mean Corpuscular Haemoglobin Concentration
Describes a calculation of the amount of haemoglobin per unit volume in a single red blood cell
Describe the reticulocyte count
Describes a count of the number of immature RBCs in the bone marrow.
(if the cause if anaemia is a production issue, this will be low. If the cause is a removal issue, this will be high)
Describe the use of Ferratin in testing for anaemia
Ferritin is a blood protein that contains Iron.
Low ferritin indicates the body’s iron stores are low, which may indicate iron deficiency anaemia.
When may ferratin levels increase? Why?
May increase during inflammation.
As ferritin is an acute phase reactant
What types of anaemia present with a low MCV? (3)
Iron Deficiency Anaemia (most common)
Thalassaemia
Sideroblastic anaemia
What types of anaemia present with a normal MCV? (5)
Acute Blood Loss
Anaemia of chronic disease
Bone marrow failure
Hypothyroidism
Pregnancy
What types of anaemia present with a high MCV? (3)
B12/Folate deficiency anaemia
Alcohol excess
Antifolate drugs (phenytoin)
What effect does phenytoin have on blood cells?
Can cause folate deficiency, leading to macrocytic anaemia
Where in the intestine is iron absorbed? And how?
Duodenum
Iron ions are actively transported into duodenal intestinal epithelial calls by the intestinal haem transporter (HCP1).
What type of anaemia is iron deficiency anaemia?
Microcytic
Give 4 causes of iron deficiency anaemia
Blood loss (menorrhagia, GI bleeding, Hookworm)
Poor diet/poverty (reduced iron intake)
Malabsorption (coeliac disease)
Pregnancy
Give 5 clinical features of iron deficiency anaemia
Anaemic features (fatigue, dyspnoea, faintness)
Brittle nails/hair
Koilonychia (spoon-shaped nails)
Atrophic glossitis (smooth/glossy tongue)
Angular stomatitis/cheilosis (ulcers in corners of mouth)
If microcytic anaemia does not respond to iron therapy, what could it be? Describe this condition.
Sideroblastic anaemia
Describes condition characterised by ineffective erythropoiesis resulting in increased iron absorption in the duodenum and iron loading in the bone marrow.
Define anaemia of chronic disease and describe it’s cause.
Describes anaemia secondary to chronic disease.
Involves the polypeptide hepcidin (produced by the liver).
Hepcidin production increases in chronic diseases, inhibiting the release of iron from macrophages. Hepcidin ultimately inhibits iron transport and absorption.
Give 4 common conditions causing anaemia of chronic disease
Tuberculosis
Crohn’s disease
Rheumatoid Arthritis
SLE
How is anaemia of chronic disease treated? (2)
Treat underlying chronic condition.
Erythropoietin (EPO)
Describe 2 categories of macrocytic anaemia
Megaloblastic - Characterised by presence of megaloblasts (b12/folate deficiency)
Non-megaloblastics - Erythroblasts are normal (alcohol excess, pregnancy)
Where is vitamin B12 absorbed?
Ileum (small intestine)
What factor must be present for Vitamin B12 to be absorbed?
Intrinsic factor
Where is intrinsic factor (important for B12 absorption) produced?
Parietal cells of the stomach