L6 - interpreting the full blood count

Question 1

The ‘normal range’ changes with age and co-morbidities, name another one

Answer 1

sex/ ethnicity/ location

Question 2

How is the ‘normal range’ calculated

Answer 2

Central 95% of a healthy population, so you can be healthy and outside the normal range

Question 3

When is mean cell haemoglobin as useful measure to take?

Answer 3

assessment of anaemia - reduced in iron deficiency and increased or normal in macrocytic anaemias

Question 4

A reticulocyte count is a measurement of the number of circulating immature erythrocytes, give an example of when this would be increased and decreased

Answer 4

Increased - haemolytic anaemia - more are being made to make up for the loss of mature ones/ recent blood loss/ recovery from bone marrow suppression/response to EPO/response to iron or B12/folate replacement

Decreased - Bone marrow failure

Question 5

polycythemia is used to describe an increased haematocrit in the blood, packed cell volume measures this, mean cell volume is another test, what disease is this the most important paramater to screen for?

Answer 5

MCV - looks at the size of RBCS’s - will be raised in macrocytic anaemia and lowered in microcytic anaemias (TAILS)

Question 6

When would a blood film be required

Answer 6

When a sample falls outside of the normal range/ if there is a significant change from the normal within the normal range/ analyser thinks there are abnormal cells present

Question 7

What two types of result would be considered ‘abnormal’ and need further investigation?

Answer 7

Outside the normal range/significant change from someone’s baseline - could still be in the ‘normal’ range

Question 8

When spun out a blood sample can be separated into plasma, a ‘buffy’ coat and hematocrit. What makes up each of these?

Answer 8

Hematocrit - RBC’s
Buffy coat - WBC’s and platelets
Plasma - Other blood cells, hormones, nutrients, water etc.

Question 9

Give an example of a disease where we’d see the ‘haemoglobin’ - paramater of the FBC change

Answer 9

NOTE - This paramater measures for the conecntration of Hb in the peripheral blood. Could change with haemolysis (clotted Hb goes up but this measures free Hb)/dehydration (reduction in plasma)/diuretic

Question 10

Give an example of a disease where red celll count would go up and one where it would go down

Answer 10

Down - Iron deficiency anaemia

Up - thalassaemia trait (more is made to compensate for small size)

Question 11

What parameter of a FBC is low if RBC’s are ‘hypochromic’?

Answer 11

MCH

Question 12

If cells are ‘dimorphic’, what does this indicate to the professional?

Answer 12

That there are two distinct populations of RBC’s (commonly seen after a blood transfusion

Question 13

What does ‘polychromasia’ mean?

Answer 13

Presence of reticulocytes in peripheral blood - be able to recognise this

Question 14

look at lecture near the bottom at all the types of blood films, very useful

Answer 14

t

Question 15

In what disease would we see schistocytes on a blood film - Sheared RBC fragments

Answer 15

Microangiopathic haemolytic anaemia

Question 16

When would we see pencil cells and some target cells on a blood film?

Answer 16

Iron deficiency anaemia

Question 17

Be able to distinguish on a blood film between falciparum and ovale

Answer 17

T - ovale have ruffled appearance. Falciparum have clear deposits in them, look at lecture

Question 18

When would we see ‘howell jolly bodies’ - fragments of DNA in the RBC’s?

Answer 18

Hyposplenism and vitamin B12/folate deficiency

Question 19

When would we see Heinz bodies (inclusions of RBC’s consisting of denatured Hb) and blister cells?

Answer 19

G6PDH deficiency -> less NADPH -> required for glutathione functioning -> increased oxidative stress -> damaged to and cross linking of n (L1 has picture)

Question 20

What is Red cell distribution width (RDW)?

Answer 20

variation in the size of the RBC

Question 21

In iron deficienct anaemia what will the results be for the following?
Hb, MCV, retic count, retic Hb count, blood film

Answer 21

Hb, MCV - down
Retic count - down
Retic Hb count - down
Blood film - hypochromic, penic cells and target cells potentially

Question 22

in spherocytosis will MCHC go up or down?

Answer 22

Up - concentration goes up but actual Hb stays same cos of shape

Question 23

On a blood film how would we distinguish a vitamin B12 deficiency?

Answer 23

hypersegmented neutrophils/circulating granulocyte precursors/ tear drop RBC’s/ howell-jolly bodies

Question 24

Differentiate between MCH and MCHC

Answer 24

mean cell haemoglobin and mean cell - average amount of Hb in each RBC/haemoglobin concentration - average concentration of Hb in each RBC

Question 25

When would we see a thrombocytopenia?

Answer 25

leukemia/splenomegaly (blood pooling)