6.1 Red Cells Part 2

Question 1

What influences the amount of haemoglobin in the body?

Answer 1

Age
Sex
Ethnic origin
Time of day sample taken
Time to analysis

Question 2

What are the reference ranges for heamoglobin?

Answer 2

Male 12-70 (140-180)
Male >70 (116-156)

Female 12-70 (120-160)
Female>70 (108-143)

Question 3

What are the clinical features in anaemia?

Answer 3

Tiredness/pallor
Breathlessness
Swelling of ankles
Dizziness
Chest pain 

(All due to tissue hypoxia)

Question 4

What are the clinical features of anaemia

Answer 4

Evidence of bleeding- menorrhagia, dyspepsia
Symptoms of malabsorbtion- diarrhoea, weight loss
Jaundice
Splenomegaly/lymphadenopathy

Question 5

What are the different categories of causes of anaemia

Answer 5

Bone marrow, cellularity, stroma, nutrients
Red cell- membrane, haemoglobin, enzymes
Destruction/Loss- Bleeding, Haemolysis, Hypersplenism

Question 6

How can red blood cells present under the microscope?

Answer 6

Hypochromic microcytic- small cells with not much heamoglobin in them

Normochromic normocytic- normal size, normal haemoglobin content

Marcolytic- big

Question 7

What does a FBC tell you about anaemia?

Answer 7

Heamoglobin total heamoglobin in the body

MCV- size of cell

MCH- amount of haemoglobin in cell

Question 8

What does the type of the anaemia tell you about what tests to do much

Answer 8

Hypochromic microcytic- serum ferritin- (differentiate between iron deficiency and thalassaemia)

Normochromic normocytic- reticulocyte count ( low reticulocyte= damage to bone marrow, high reticulocyte= bleeding/heamolysis)

Macrolytic- B12/ folate , bone marrow

Question 9

What does serrum ferritin tell you about the diagnosis of aneamia

Answer 9

Low- iron deficiency

Normal/increased- thalassaemia, secondary anaemia, also increases with active inflammatory process which can mask iron deficiency

Question 10

How is iron metabolised?

Answer 10

Total body iron around 4g, anything you don’t need is pooed out

Pretty much all body iron is bound to heamoglobin.

Here iron- better absorbed from animals, absorbed by ferroportin. If too much iron ferroportin doesn’t ingest

Hepcidin- key to understanding secondary anaemia

Question 11

What does hepcidin

Answer 11

Binds to ferroportin and prevents iron absorption. It is synthesised by the liver. It is also increased in response to inflammation therefore leading to anaemia.

Question 12

What causes iron deficiency anaemia and how do you find this

Answer 12

Take a good history. Look for:

Dyspepsia, Gi bleeding, other bleeding
Diet (Children and elderly)
Increased requirement- pregnancy
Signs of iron deficiency(koilonychia, angular stomatitis)
Abdominal and rectal examination

Question 13

How do you treat iron deficiency anaemia

Answer 13

Correct the deficiency (normally oral iron is sufficient)
IV iron if intolerant of oral, blood transfusions rarely indicated
Correct the cause- diet, ulcer therapy, gynae interventions, surgery

Question 14

What does the reticulocyte count indicate?

Answer 14

Increased- acute blood loss/haemolysis

Normal/Low- hypoplasia, marrow infiltration

Question 15

What causes haemolytic anaemia?

Answer 15

Accelerated red cell destruction (decreased Hb)

Compensation by bone marrow (increased reticulocytes)

Level of haemoglobin, balance between red cell production and destruction

Haemolytic anaemia can be extravascular, instravacular or both

Question 16

What are the different types of haemolytic anaemias?

Answer 16

Congenital- hereditary spherocytosis, enzyme dificiency, heamoglobinopathy

Acquired- auto immune haemolytic anaemia

Mechanical anaemia e.g. artificial valve
Severe infection
PET/HSS/TTP (pregancy?)

Question 17

What test can you do to detect if there are antibodies that will break down red cells?

Answer 17

Direct antibody test, reactant (igG) binds to Ab or complement on red cell surfaces and causes agglutination in vitro. Implies immune basis for haemolysis

Positive- immune mediated

Negative- non immune mediated

Question 18

What the different types of antibodies?

Answer 18

Warm auto-antibodies- auto immune, drugs, chronic lymphoma?

Cold auto-antibodies- cold disease (CHAD), infections, lymphoma

Alloantobodies- transfusion reaction

Question 19

What do you investigate in heamolytic anaemia?

Answer 19

FBC- raised
reticulocyte count- raised 
Blood film- raised
Serum bilirubin- raised 
Serum haptoglobin- made in liver, maps up free heamoglobin, therefore down

Question 20

How do you treat haemolytic anaemia?

Answer 20

Support marrow function- folic acid

Correct cause- immunosuppression if autoimmune
Steroids
Treat trigger e.g. CLL, lymphoma
Remove site of red cell destruction (splenectomy)
Treat sepsis, leaky valvemmalignancy etc
Consider transfusion

Question 21

What does a B12/folate, bone marrow tests show

Answer 21

Megalobalstic - B12 deficiency

Non- megaloblastic- myelodysplasia, marrow infiltration, drugs

Question 22

What are the heamotinics

Answer 22

B12, folate, ferritin

Question 23

How does one become B12 deficient

Answer 23

B12 binds to intrinsic factor in stomach and are absorbed in the terminal ileum. Can develop antibodies to the intrinsic factor

Question 24

What are the presenting symptoms of B12/folate deficiency and what causes it?

Answer 24

Pernicious anamei and gastric/ileal disease cause B12 deficiency

Anaemia
Neurological symptoms (subacute, combined, degeneration of the cord in B12 deficiency) ………
Lemon yellow tinge to skin, bilirubin LDH, red cells friable

Question 25

What causes Folate deficiency?

Answer 25

Diet
Increased requirements (haemolysis)
GI pathology (e.g. coeliac disease)

Question 26

How do you treat B12 deficiency?

Answer 26

B12 injections, loading dose then 3 monthly maintenance

Question 27

How do you treat folate deficiency

Answer 27

oral folate replacement