B3 - Anaemia

Question 1

haematocrit

Answer 1

○ Haematocrit: percentage of whole blood volume comprised of red blood cells

Question 2

anaemia

Answer 2

• A reduction in haemoglobin (Hb) concentration below the normal range for the age and gender of the individual
  
  • Usually accompanied by a reduction in red cell count and haematocrit

Question 3

anaemia symptoms in old people

Answer 3

heart failure, chest pain - because rate is increased to compensate for low oxygen

Question 4

tachycardia

Answer 4

Increased cardiac output: tachycardia; heart murmur

Question 5

jaundice causes

Answer 5

□ Haemolytic - Red cells are being broken down in the spleen creating bilirubin, premature red cell destruction
□ Megaloblastic - bone marrow cannot make red blood cells properly due to low Vit B12 or folate so the red blood cells die within the bone marrow
□ eyes, skin colour appear yellow

Question 6

koilonychia

Answer 6

severe long standing iron deficiency anaemia - dent in the fingernail

Question 7

stool colour change in haemolysis

Answer 7

§ Stool colour change: haemolysis - from bilirubin being made from destruction of haem

Question 8

2 main causes of anaemia

Answer 8

• reduced red cell production

- increased loss of red cells

Question 9

reduced red blood cell production causes

Answer 9

a. Marrow failure (primary)
§ Aplastic anaemia (entire bone marrow)
□ Percentage of space that is cellular is 100% - your age
® Eg. A 40 yo person should have 40% fat and 60% cells
§ Pure red cell aplasia (just red blood cells)
§ Bone marrow dysfunction: myelodysplasia (abnormal production of bone marrow resulting in inadequate red blood cells being produced)
b. Another cause (secondary)
§ Insufficient nutrients eg. Iron, folate, B12, EPO
□ Patient history
® Dietary history
® Gut malabsorption
□ Typically anaemia without marked neutropenia or thrombocytopenia
□ Other symptoms of nutritional deficiency
§ Infection - supresses bone marrow function
§ Drugs eg. Cytotoxic chemotherapy
§ Marrow infiltration
□ Luekaemia/cancer - takes over marrow cavity and replaces cell production
□ Secondary cancer - can metastasize to the bone marrow and infiltrate

Question 10

aplastic marrow failure anaemia

Answer 10

entire bone marrow

Question 11

pure red cell aplasia bone marrow failure

Answer 11

just red blood cells

Question 12

myelodysplasia

Answer 12

§ Bone marrow dysfunction: myelodysplasia (abnormal production of bone marrow resulting in inadequate red blood cells being produced)

Question 13

percentage of cellular bone marrow

Answer 13

100% - age

Question 14

secondary bone marrow failure

Answer 14

• insufficient nutrients
• infection
• drugs
• marrow infiltration

Question 15

causes of increased loss of red cells

Answer 15

bleeding, haemolysis

Question 16

bleeding/haemorrhage

Answer 16

§ Acute:
□ easy to identify - usually some who has had an accident and is suffering from acute blood loss
§ Chronic:
□ slow bleeding, usually gastrointestinal, cancer, menorrhagia (uterine blood loss)
□ May be secondary to anticoagulant drugs (blood thinners eg. Warfarin)

Question 17

haemolysis

Answer 17

§ premature red blood cell breakdown (reduced red cell lifespan through cell destruction)
§ Inherited eg. Spherocytosis, pyruvate kinase deficiency etc.
§ Acquired eg. Secondary to infection
□ Eg. Malaria causing blackwater fever
® Dark urine resulting from burst red blood cells and free haemoglobin in blood vessel
® Hemoglobinemia - haemoglobin in blood
® Haemoglobinuria - haemoglobin in urea
§ Defect of the cell or environment (eg. Plasma)
□ Eg. Chronic renal failure creates abnormal biochemistry interfering with red blood cell membrane
□ Eg. Chronic liver disease especially secondary to excessive alcohol consumption, changes lipids in plasma which changes the makeup of the lipids in the phospholipid membrane making the membrane rigid like spherocytes which will be destroyed by the spleen, causing anaemia

Question 18

inherited haemolysis causes

Answer 18

eg. Spherocytosis, pyruvate kinase deficiency etc.

Question 19

acquired haemolysis causes

Answer 19

eg. Secondary to infection
□ Eg. Malaria causing blackwater fever
® Dark urine resulting from burst red blood cells and free haemoglobin in blood vessel
® Hemoglobinemia - haemoglobin in blood
® Haemoglobinuria - haemoglobin in urea

Question 20

haemolysis caused by defect of cell environment

Answer 20

□ Eg. Chronic renal failure creates abnormal biochemistry interfering with red blood cell membrane
□ Eg. Chronic liver disease especially secondary to excessive alcohol consumption, changes lipids in plasma which changes the makeup of the lipids in the phospholipid membrane making the membrane rigid like spherocytes which will be destroyed by the spleen, causing anaemia

Question 21

splenomegaly causes

Answer 21

§ Chronic haemolysis
§ Extramedullary haemopoiesis - red blood cells being produced in a site outside of the bone marrow
□ May be produced in the spleen - causing splenomegaly

Question 22

extramedullary haemopoisis

Answer 22

red blood cells being produced in a site outside of the bone marrow

Question 23

causes of iron deficiency

Answer 23

○ Reduced intake
§ Rare in developed world
§ Commonest form of anaemia in paediatrics
§ Mainly due to babies not starting to eat soon enough
○ Poor iron absorption/malabsorption
§ Stomach or bowel, gastrectomy,
§ Disease of upper small bowel eg. coeliac disease
§ People who don’t have a stomach
○ Chronic blood loss
§ Gastrointestinal: gastric ulcers, carcinomas of the colon (over the age of 60/70), oesophageal varices (expanded veins in the oesophagus, which occurs which severe alcoholic liver disease, causes backflow of the vessels and wide veins in the oesophagus causing bleeding with minimal trauma) diverticulosis, haemorrhoids (not common, blood loss is only a small amount)
§ Uterine: uterine bleeding
○ Increased iron usage
§ Neonates, puberty, pregnancy

Question 24

clinical features of iron deficiency

Answer 24

○ Atrophic glossitis - smooth tongue without pappilae due to atrophy or death
○ Angular cheilitis - redness and fissures at the corners of the mouth
○ Koilonychia - spoon nails

Question 25

blood film of iron deficiency anaemia

Answer 25

○ Hypochromic microcytic anaemia
○ Pale, small red blood cells, more than 1/3 central pallor
○ Pencil cells elliptical in shape / elliptocytes

Question 26

lab features of iron deficiency anaemia

Answer 26

○ Mild thrombocytosis (increased platelet count)
○ Reduced reticulocyte count (insufficient new RBC being made in BM)
○ RBC
§ (RCC) Reduced cell count
§ (Hb) Low haemoglobin
§ (MCV) low mean cell volume
§ (Hct) low haematocrit
§ (MCH) Low mean cell haemoglobin
§ (RDW) High RBC distribution width - variance in size of red blood cells, varied due to compensating erythropoiesis

Question 27

serum lab results in iron deficiency anaemia

Answer 27

○ Serum iron
§ shows how much iron is circulating in the plasma
§ Highly variable, not useful to asses iron stores
§ Likely reduced in iron deficiency
○ Serum transferrin (Tf)
§ reflects iron transporter protein
§ Increased in iron deficiency as a response to lack of iron
○ Transferrin saturation
§ % of iron transporter occupied by iron
§ reduced in iron deficiency
○ Serum ferritin
§ reflects body iron stores
§ Reduced in iron deficiency

Question 28

serum iron in iron deficiency anaemia

Answer 28

§ shows how much iron is circulating in the plasma
§ Highly variable, not useful to asses iron stores
Likely reduced in iron deficiency

Question 29

serum transferrin in iron deficiency anaemia

Answer 29

§ reflects iron transporter protein

§ Increased in iron deficiency as a response to lack of iron

Question 30

transferring saturation in iron deficiency anaemia

Answer 30

§ % of iron transporter occupied by iron

§ reduced in iron deficiency

Question 31

serum ferritin in iron deficiency anaemia

Answer 31

§ reflects body iron stores

§ Reduced in iron deficiency

Question 32

Dimorphic blood film

Answer 32

(2 morphologies)

- Partially treated iron deficiency 
- Some red cells still iron deficient, some normal

Question 33

Iron overload causes

Answer 33

○ Primary: genetic haemochromatosis (HFE gene)
§ Genetic mutation causing accumulation by over absorption
§ Venesect - take out a bag of blood every few months
○ Ineffective erythropoiesis with increased iron absorption: thalassemia
§ Excess iron due to bone marrow making red blood cells wrong, red blood cells due in bone marrow and iron is recirculated leading to accumulation of loose iron
○ Repeated blood transfusions
§ Can cause damage to heart, endocrine organs etc.

Question 34

clinical features of iron overload

Answer 34

○ Organ dysfunction from iron deposition - significant in thalassemia patients who are transfusion dependant
○ Heart, endocrine system, liver

Question 35

treatment of iron overload

Answer 35

○ Genetic: regular venesection to reduce iron level

○ Transfusion iron overload: Iron chelation therapy: given a drug to specifically remove iron from the body

Question 36

iron chelation therapy

Answer 36

given a drug to specifically remove iron from the body

Question 37

genetic haemochromatosis

Answer 37

§ Genetic mutation causing accumulation by over absorption

§ Venesect - take out a bag of blood every few months

Question 38

○ Ineffective erythropoiesis with increased iron absorption: thalassemia

Answer 38

§ Excess iron due to bone marrow making red blood cells wrong, red blood cells due in bone marrow and iron is recirculated leading to accumulation of loose iron