Red Cells 2

Question 1

what is the normal haemaglobin range for males 12-70 years old?

Answer 1

140-180

Question 2

what is the normal haemaglobin range for males > 70 years old?

Answer 2

116-156

Question 3

what is the normal haemaglobin range for females aged 12-70?

Answer 3

120-160

Question 4

what is the normal haemaglobin range for females > 70 years old?

Answer 4

108-143

Question 5

what does MCH stand for?

Answer 5

mean cell haemaglobin

low would mean hypochromic

Question 6

what does MCV stand for?

Answer 6

mean cell volume (cell size)

Question 7

what would be the next investigation if red cell indices and blood film showed hypochromic microcytic anaemia?

Answer 7

serum ferritin

Question 8

what would be the next investigation if red cell indices and blood film showed normochromic normocytic anaemia?

Answer 8

reticulocyte count

Question 9

what would be the next investigation if red cell indices and blood film showed macrocytic anaemia?

Answer 9

B12/folate levels
bone marrow biopsy

Question 10

what type of anaemia is shown by the blood film on the right?

Answer 10

hypochromic, microcytic anaemia

Question 11

A blood film shows hypochromic microcytic anaemia. A serum ferritin is taken and is found to be low. What could this indicate as the cause for anaemia?

Answer 11

iron deficiency

Question 12

A blood film shows hypochromic microcytic anaemia. A serum ferritin is taken and is found to be normal/increased. What could this indicate as the possible causes for anaemia?

Answer 12

• thalassaemia
• secondary anaemia
• sideroblastic anaemia

Question 13

total body iron in g

Answer 13

4g
- lose on average 1-2mg per day
- dietary intake balanced by loss

Question 14

how is iron absorbed and what happens next?

Answer 14

• absorbed in duodenum: Fe2+ > Fe3+
• transported from enterocytes and macrophages by ferroportin
• transported in plasma bound to transferrin
• stored in cells as ferritin

Question 15

what is the role of Hepcidin?

Answer 15

Hepcidin synthesised in hepatocytes in response to increased iron levels and inflammation.
- block ferroportin so reduces intestinal iron absorption and mobilisation from reticuloendothelial cells

Question 16

what are some causes of iron deficiency?

Answer 16

• malnutrion
• GI blood loss
• mennorhagia
• malabsorption e.g. gastrectomy or coeliac disease

Question 17

Iron deficiency management

Answer 17

Correct the deficiency:
- oral iron usually sufficient
- IV iron if tolerant of oral
- blood transfusion rarely indicated

Correct the cause:
- diet
- ulcer therapy
- gynae interventions
- surgery

Question 18

A blood film shows normochromic normocytic anemia. A reticulocyte count is also increased. What could be the possible causes for this?

Answer 18

• acute blood loss
• haemolysis

Question 19

A blood film shows normochromic normocytic anemia. A reticulocyte count is taken and is normal/low. What could be the possible causes for this?

Answer 19

• secondary anaemia (of chronic disease)
• hypoplasia
• marrow infiltration

Question 20

Describe secondary anaemia

Answer 20

• ‘anaemia of chronic disease’
• 70% normochromic normocytic, 30% hypochromic microcytic
• defective iron utilisation: increased hepcidin in inflammation, ferritin normal or elevated (an acute phase reactant)
• identifiable underlying disease e.g. infection, inflammarion, malignancy, renal impairment (role of erythropoietin)

Question 21

what are some causes for haemolytic anaemia?

congenital and acquired

Answer 21

congenital:
- hereditary sperocytosis (HS)
- enzyme deficiency (G6PD deficiency)
- haemoglobinopathy (HbSS)

acquired:
- auto-immune haemolytic anaemia, DAT+ (extravascular)
- mechanical e.g. artificial valve (intravascular)
- severe infection/DIC (intravascular)
- PET/HUS/TTP (intravascular)

Question 22

describe a direct antiglobulin test

Answer 22

• detects antibody or complement on red cell membrane
• reagent contains either anti-human IgG or anti-complement
• reagent binds to Ab (or complement) on red cell surface and causes agglutination in vitro
• implies immune basis for haemolysis

Question 23

haemolytic anaemia diagnostic investigations

Answer 23

Is patient haemolysing?
- FBC, reticulocyte count, blood film
- serum bilirubin (unconjugated/indirect), LDH
- serum haptoglobin

What is the mechanism?
- history and exam
- blood film
- direct antiglobulin test (Coombs’ test)
- urine for haemosiderin/urobilinogen

Question 24

Haemolytic anaemia management

Answer 24

• Support marrow function > folic acid
• immunosuppression if autoimmune > steroids, treat trigger e.g. CLL, lymphoma
• remove site of red cell destruction > splenectomy
• treat sepsis, leaky prosthetic valve, malignancy etc. if intravascular
• consider transfusion

Question 25

describe vitamin B12 absorption

Answer 25

- dietary B12 binds to intrinsic factor, secreted by gastric parietal cells - B12-IF complex attaches to specific IF receptors in distal ileum - vitamin B12 bound by transcobalamin II in portal circulation for transport to marrow and other tissues.

Question 26

describe pernicious anaemia

Answer 26

- most common cause of B12 deficiency in western populations - autoimmune disease - antibodies against intrinsic factor (diagnostic) and gastric parietal cells (less specific) - malabsorption of dietary B12, symptoms take 1-2 years to develop (stores last a long time)

Question 27

Megaloblastic anaemia treatment

Answer 27

- replace vitamin B12 deficiency: B12 intramuscular injection, oral if not pernicious anaemia, loading dose then 3 monthly maintenance folate deficiency: oral folate replacement, ensure B12 normal if neuropathic symptoms

Question 28

what are some causes of non-megaloblastic macrocytic anaemia?

Answer 28

- alcohol - drugs e.g. methotrexate, antiretrovirals, hydroxycarbamide - disordered liver function - hypothyroidism - myelodysplasia