OUTLINE THE MECHANISMS OF ANAEMIA

Question 1

What are the 3 outline causes of anaemia?

Answer 1

reduced production of erythrocytes, increased destruction of erythrocytes, reduced production or defective haemoglobin

Question 2

what are the signs of anaemia?

Answer 2

pallor (especially conjunctiva), tachycardia, glossitis, koilonychia (spoon nails), dark urine

Question 3

when are you most likely to see dark urine?

Answer 3

in haemolytic anaemia as RBCs are broken down and excreted too readily

Question 4

what are the symptoms of anaemia in mild cases?

Answer 4

weakness, tiredness, inability to exercise, dizziness, palpitations, shortness of breath

Question 5

what are symptoms of anaemia in severe cases?

Answer 5

confusion, thirst, loss of consciousness, jaundice, splenomegaly, hepatomegaly, angina, cardiac failure, fever

Question 6

what is the differentiation of multipoint haematopoietic stem cells to common myeloid progenitor cells regulated by?

Answer 6

cytokines and haematopoietic niches in the bone marrow

Question 7

how do the kidney cells know when to excrete erythropoietin?

Answer 7

in hypoxia we get increased levels of HIF which increases the production of EPO

Question 8

what are pure red cell aplasias?

Answer 8

an anaemia affecting the precursors to red blood cells only.

Question 9

what’s the difference between primary and secondary pure red cell aplasia?

Answer 9

primary is idiopathic or an autoimmune disease whereas secondary is as a result of exposure to a pathogenic agent

Question 10

what is pancytopenia?

Answer 10

Pancytopenia is a condition that occurs when a person has low counts for all three types of blood cells: red blood cells, white blood cells, and platelets. Pancytopenia is usually due to a problem with the bone marrow that produces the blood cells.

Question 11

describe haematopoietic stem cell exhaustion

Answer 11

as the haematopoietic stem cell divides it produces 1 cell that differentiates into a progenitor cell and another that forms another HSC (self-renewal). if something affect the DNA in a HSC then you can lose this self-renewal functioning the cells will only differentiate to form progenitor cells. this is a cause of bone marrow failure

Question 12

what can cause bone marrow failure?

Answer 12

congenital changes, infections, malignancies, autoimmune disease, drugs, chemicals

Question 13

what is haemolytic anaemia?

Answer 13

premature destruction of RBCs due to extrinsic or intrinsic mechanisms. the anaemia develops if the bone marrow is unable to match the destruction of RBCs with the formation of RBCs.

Question 14

what are extrinsic and intrinsic causes of haemolytic anaemia?

Answer 14

extrinsic- when the erythrocyte is healthy but it is destroyed by an external pathological process
intrinsic- when there’s something wrong with the erythrocyte so it is destroyed

Question 15

what is autoimmune haemolytic anaemia?

Answer 15

when autoantibodies are found as the immune system produces antibodies that recognise their own erythrocytes as foreign and mediate their destruction.

Question 16

how can you diagnose haemolytic anaemia from blood films?

Answer 16

you get chunks of RBcs and blue-tinged reticulocytes and nucleated red blood cells and very small red blood cells= these mistakes indicate that the body is struggling with haematopoiesis

Question 17

what is haemoglobinopathy?

what’s the most common type?

Answer 17

an inherited blood disorder in which an individual has an abnormal form of haemoglobin (variant) or decreased production of haemoglobin (thalassaemia)
common= sickle cell anaemia

Question 18

describe iron related anaemia

Answer 18

a deficiency in iron directly impacts the amount of oxygen that can be bound to haemoglobin

Question 19

what can cause an iron deficiency?

Answer 19

not eating enough, lack of absorption e.g. gastric atrophy, alcoholism, duodenitis, ulceration, Crohn’s disease

Question 20

what would you see on a blood film of someone who had iron-deificent anaemia?

Answer 20

the RBcs would be hypo chromic (pale) and microcytic (small), they would seem to be empty due to lack of staining in centre

Question 21

where can we get iron from naturally?

Answer 21

dark-green, leafy vegetables, iron-fortified cereals, whole grains, beans, nuts, meat, apricots, prunes, raisins and iron tablets

Question 22

what makes the absorption of iron difficult?

Answer 22

tea, coffee, calcium, antacids, PPIs, wholegrain cereals

Question 23

what is sideroblastic anaemia?

Answer 23

an impaired ability of the bone marrow to produce normal red blood cells . In this condition, the iron inside red blood cells is inadequately used to make hemoglobin, despite normal amounts of iron. the iron isn’t properly incorporated into the haem

Question 24

what is the cause of sideroblastic anaemia?

Answer 24

as a result of mutation/deletion of genes regulating th expression of key enzymes in haem synthesis

Question 25

what would you see in a blood film of someone with sideroblastic anaemia?

Answer 25

iron sat within mitochondria surrounding the erythocytes rather than being packed away

Question 26

what are key regulators we need in our diet for haem production? what else are B12 and folate required for?

Answer 26

vitamin B6, B12 and folate

essential for DNA synthesis in erythrocyte proliferation so a reduction can reduce erythropoiesis

Question 27

when is it common to see a vitamin B12 and folate deficiency?

Answer 27

malabsorption, malnutrition, pregnancy, poverty, small bowel disease, gastrectomy, fish tapeworm, antacids

Question 28

where can we get B12 and folate from in our diet?

Answer 28

meat, fish, milk, eggs, fortified breakfast cereals, soy products

Question 29

what is microcytic and macrocytic anaemia?

Answer 29

microcytic is when you have a low mean corpuscular volume and microcytic is a high mean corpuscular volume.

Question 30

what are common causes of microcytic anaemia?

Answer 30

iron deficiency, lead poisoning, sideroblastic anaemia if RBC is low. thalassemia is likely if RBC is high.

Question 31

what are the common causes of normocytic anaemia?

Answer 31

haemolytic anaemia and bone marrow disorders.

Question 32

what are the common causes of macrocytic anaemia?

Answer 32

vitamin B12 deficiency, folic acid deficiency, liver disease, deficiency in intrinsic factor or reticulocytosis (increase in reticulocytes)

Question 33

what is spherocytosis?

Answer 33

the presence of sphere-shaped RBCs in the blood. it is a type of haemolytic anaemia. caused by an increased permeability for sodium and water

Question 34

what is aplastic anaemia?

Answer 34

when the body doesn’t produce sufficient blood cells. can cause pancytopenia

Question 35

what is haemorrhagic anaemia?

Answer 35

a low RBC due to a loss of blood.