Introduction to Haematology

Question 1

When you centrifuge blood what three layers does it produce?

Answer 1

Plasma
Buffy coat
Red blood cells

Question 2

What can be found in the plasma layer of centrifuged blood?

Answer 2

Clotting or coagulation factors
Albumin
Antibodies

Question 3

What is found in the buffy coat?

Answer 3

Platelets

White cells

Question 4

What are some features of stem cells?

Answer 4

Totipotent (can differentiate into all cells of the blood)
Self-renewing
Regulated by hormones

Question 5

Where is bone marrow mostly found?

Answer 5

Bones (esp. axial in elderly)

Question 6

What is the appearance of bone marrow?

Answer 6

Stroma + sinusoids

Fat cells

Question 7

What hormone regulates erythropoiesis? What organ produces it?

Answer 7

EPO (erythropoietin) made in kidney in response to hypoxia

Question 8

What is a normal reticulocyte count?

Answer 8

Usually about 1%

Can rise to 10% if you are bleeding

Question 9

What is reticulocyte count essentially a measure of?

Answer 9

Red cell production (as they are the early RBCs)

Question 10

Do reticulocytes have a nucleus?

Answer 10

Like RBCs they do not

Question 11

What is polycythaemia?

Answer 11

Too many red cells

Question 12

What red cells do you see in renal failure?

Answer 12

May have burr cells (cells that look like sea urchins)

Question 13

What regulates platelet production? Where is it made?

Answer 13

Thrombopoitein

Liver

Question 14

What is the lifespan of a platelet?

Answer 14

7 days

Question 15

What things may cause thrombocytosis?

Answer 15

Reactive thrombocytosis (to cancer, infection, bleeding etc.) 
Myeloid malignancies

Question 16

What may cause thrombocytopenia?

Answer 16

Marrow failure

Immune destruction

Question 17

Which drugs can alter the function of platelets?

Answer 17

Aspirin
Clopidogrel
Abciximab

Question 18

What is the function of neutrophils?

Answer 18

Ingest + destroy pathogens

Esp. bacteria + fungi

Question 19

What is the lifespan of neutrophils?

Answer 19

1-2 days

Question 20

How long does it take a neutrophil to respond to infection?

Answer 20

Few hours

Question 21

What interleukin is predominantly produced by macrophages?

Answer 21

IL-17

Question 22

What may cause neutrophilia?

Answer 22

Infection, inflammation (e.g. post MI, post-op, RA)

Question 23

What may cause neutropenia?

Answer 23

Subsaharan africans may have lower levels
Decreased production (e.g. marrow failure, drugs) 
Increased consumption (e.g. sepsis, autoimmune) 
Altered function (e.g. chronic granulomatous disease)

Question 24

What is the function of monocytes?

Answer 24

Ingest + destroy pathogens

Question 25

What are the monocytes that migrate into tissues called?

Answer 25

Macrophages

Question 26

Give examples of macrophages?

Answer 26

Lung alveolar macrophages | Liver Kupffer cells

Question 27

What can cause monocytosis?

Answer 27

Usually assoc. with neutrophilia | Mycobacteria infection

Question 28

What can cause monocytopenia?

Answer 28

Hairy cell leukaemia

Question 29

Eosinophils are involved in immunity against what?

Answer 29

Parasites Also involved in allergy

Question 30

Name 2 features of lymphocytes that differ from myelocytes?

Answer 30

Adaptive, immunolgocial memory

Question 31

What causes lymphocytosis?

Answer 31

Viral infections mostly (e.g. IM, pertussis)

Question 32

What causes lymphopenia?

Answer 32

Post-vial common | Lymphoma

Question 33

What are the functions of B cells?

Answer 33

Making antibodies/precursors for making antibodies

Question 34

What are the functions of T cells?

Answer 34

Helper - regulates adaptive immune system Cytotoxic - kills pathogens Regulatory - dampens immune system

Question 35

Where are B cells produced?

Answer 35

Bone marrow

Question 36

Where are T cells produced?

Answer 36

Thymus

Question 37

What are the roles of antibodies?

Answer 37

Adaptors between pathogens + clearance systems Opsonisation Fix complement Block binding

Question 38

What is opsonisation?

Answer 38

Process of marking a pathogen for destruction to be engulfed by a macrophage

Question 39

Where do B cells reside in the lymph node?

Answer 39

Follicles

Question 40

Where do T cells reside in lymph nodes?

Answer 40

Paracortex

Question 41

Where do plasma cells reside in lymph nodes?

Answer 41

Medulla

Question 42

Where do B cells undergo expansion and selection?

Answer 42

Germinal centre of lymph node

Question 43

What does the HLA gene encode for?

Answer 43

MHC protein - which are responsible for the regulation of the immune system

Question 44

What are the two classes of HLA genes and where are they found?

Answer 44

Class 1 - all nucleated cells | Class 2 - on APC cells

Question 45

Give examples of APC cells?

Answer 45

B cells Dendritic cells Macrophages

Question 46

What haematological abnormalities can hepatic disease lead to?

Answer 46

Anaemia | Deficient clotting factors

Question 47

What haematological abnormalities can renal disease lead to?

Answer 47

Anaemia | HUS

Question 48

What haematological abnormalities can CV disease lead to?

Answer 48

Anaemia

Question 49

What haematological abnormalities can respiratory disease lead to?

Answer 49

Polycythaemia

Question 50

What haematological abnormalities can GI disease lead to?

Answer 50

Anaemia

Question 51

What tests may be useful in haematology?

Answer 51

``` FBC Clotting time for clotting factors Bleeding time for platelets Platelet + leucocyte function tests Haematinics (B12, folate, iron) Marrow aspirate + trephine Lymph node biopsy Imaging ```

Question 52

Where is a marrow aspirate/trephine commonly taken from now?

Answer 52

Iliac crest

Question 53

What two kinds of pulp are found in the spleen and what is their functions?

Answer 53

White: immune Red: red cells maturation

Question 54

What does hypersplenism lead to?

Answer 54

Pancytopenia - red/white cells spend too much time in spleen and not circulating around

Question 55

What does hyposplenism lead to?

Answer 55

Infections with encapsulated bacteria (meningococcus, pneumococcus, haemophilus) Red cell changes

Question 56

What things may cause splenomegaly?

Answer 56

Inections, e.g. EBV, CMV, TB, Brucella, malaria, leishmaniasis Haematological malignancy Portal hypertension Haemolytic conditions (immune, spherocytosis, thalassaemia etc.) Connective tissue dx (Felty's, SLE) Malignancy, sarcoid, amyloid, genetic