FBC

Question 1

What can a FBC detect?

Answer 1

Hb conc
Haematocrit
Red cell count
Mean cell volume
Mean cell Hb
Mean cell Hb conc
Reticulocyte count
WBC differential
Platelet count

Question 2

What is haematocrit?

Answer 2

Also known as packed cell volume - The proportion of blood taken up by RBC

Question 3

What is red cell count used for?

Answer 3

Used in microcytic anaemias

Question 4

What is mean cell volume?

Answer 4

Shows the size of RBCs, used to determine the type of anaemia.
PCV / RBC count

Question 5

What is MCH?

Answer 5

Hb / RBC count

Question 6

What is MCHC?

Answer 6

Hb / PCV

Question 7

What is WBC differential?

Answer 7

Sum of the leukocytes and immature precursors.

Neutrophils should be greater than lymphocytes in adults but the opposite in children.

Question 8

What is a blood film?

Answer 8

Shows if the FBC is accurate, clumping, shapes of RBC, Hb content and presence of blasts

Question 9

What is hypochromic?

Answer 9

Pale, low Hb content

Question 10

What is EDTA Ig?

Answer 10

EDTA collates Ca in the blood to prevent clotting. The Ig causes clumping in a test tube but is asymptomatic in the body.

Question 11

What does a low Hb conc mean?

Answer 11

<13g.dL males or <11.5g.dL = ANAEMIA

<130g.L, <115g.L

Question 12

What does a low MCHC show?

Answer 12

Hypochromic = microcytic anaemia

Question 13

What does a high MCHC show?

Answer 13

Hyperchromic due to spherocytosis and sickle cell

Question 14

What does a high reticulocyte count show?

Answer 14

Attempt to increase RBC production due to HAEMOLYSIS

Question 15

What does a high haematocrit and red cell count show?

Answer 15

ABSOLUTE POLYCYTHEMIA >55%

Question 16

What is polycythemia vera?

Answer 16

A BM disease causing increased production of blood cells. Precursor to acute myeloid leukaemia.

Question 17

How does polycythemia present?

Answer 17

Splenomegaly, pluritis (itching), plethoric face (red faced)

Question 18

How is absolute polycythemia treated?

Answer 18

Venosection to remove the blood volume and hydrocycarbiamide

Question 19

What does the presence of immature leukocytes show?

Answer 19

Sepsis or leukaemia

Question 20

What does a high neutrophil count show?

Answer 20

Neutrophilia - Pregnancy or corticosteroids

Question 21

What does a low neutrophil count show?

Answer 21

Neutropenia - reduced production from deficiencies, increased destruction from AI or chemo, sequestration

Question 22

How is neutropenia treated?

Answer 22

Prophylactic antibiotics and G-CSF to boost neutrophil count

Question 23

What is demargination?

Answer 23

Neutrophils sit on the vascular endothelium to respond quickly in high numbers. But during a seizure the neutrophils dissociate from the endothelium and the seizure then presents as an infection due to the neutrophilia.

Question 24

What is lymphocyte count affected by?

Answer 24

Production under GF control
Antigen driven proliferation during infection
Sequestration within lymphoid tissue
Apoptosis through receptor ligation and GF deprivation and phagocytosed by macrophages to prevent intracellular spillage

Question 25

What does a monoclonal expansion of lymphocytes suggest?

Answer 25

Malignancy in the absence of infection

Question 26

What may cause lymphocytosis?

Answer 26

Smoking, splenectomy, infection, lymphoproliferative disease

Question 27

What is Hodgkin's lymphoma?

Answer 27

Affects B lymphocytes and starts in the lymphatic system

Question 28

What is Non-Hodgkin's lymphoma?

Answer 28

Affects both B and T lymphocytes and can start either in the lymphatic or in other organs.

Question 29

What is leukaemia?

Answer 29

Neoplasm that arises in the marrow and spreads to blood

Question 30

What may be the cause of lymphopenia?

Answer 30

SCID

Question 31

What is suggested by an increase in monocytes?

Answer 31

Infection of leukaemia

Question 32

What is suggested by a decrease in monocytes?

Answer 32

Genetic defect in maturation or BM infiltration

Question 33

What is suggested by an increase in basophils?

Answer 33

Malignancy, infection, HYPOthyroidism

Question 34

What is suggested by a decrease in basophils?

Answer 34

HYPERthyroidism, steroids, anaphylaxis

Question 35

What is suggested by an increase in eosinophils?

Answer 35

Parasitic infection, allergy, drug reaction

Question 36

What is suggested by a decrease in eosinophils?

Answer 36

Alcohol, steroids

Question 37

What is thrombocytopenia?

Answer 37

A reduced platelet count of <150cells/cm3 with the increased risk of excessive bleeding

Question 38

What causes thrombocytopenia?

Answer 38

Underproduction - reduced megakaryocytes levels. Caused by infections, drugs (chemo), vit B12 and folate deficiency, aplastic anaemia Increased destruction - Increased megakaryocyte levels. Caused by ITP, lupus, DIC, CVID Sequestration - within the spleen due to cirrhosis, virus or malignancy

Question 39

What is ITP? How is it treated?

Answer 39

Immune thrombocytopenic purpura. Autoimmune related due to HIV or Hep C. Treated with steroids, azathiopine and splenectomy to remove autoIg.

Question 40

What may cause abnormal platelet function and therefore prolonged bleeding time?

Answer 40

Van Willebrand disease detected by PFA-100 test Aspirin - inhibits cyclo-oxygenase irreversibly for 1 week (needed for thromboxane production) Iron and folate deficiency