Session 6-Spleen, WBCs, Cytopenia

Question 1

What types of pulp does the spleen consist of?

Answer 1

1) red pulp - sinuses lined by endothelial macrophages and cords
2) white pulp - similar structure to lymphoid follicles

Question 2

How does blood enter the spleen?

Answer 2

Via splenic artery

Question 3

Which cells pass through the white pulp?

Answer 3

White cells and plasma

Question 4

Which cells pass through the red pulp?

Answer 4

Red cells

Question 5

Why can splenomegaly lead to weight loss?

Answer 5

When spleen enlarges, can press on stomach so stomach cannot fully expand -> early satiety -> weight loss

Question 6

What are the functions of the spleen in adults? (4)

Answer 6

1) sequestration and phagocytosis of old/abnormal RBCs
2) blood pooling - platelets and RBCs rapidly mobilised during bleeding
3) extramedullary haemopoiesis
4) immunological function - 25% of T cells and 15% of B cells present in spleen

Question 7

True or false: spleen is palpated below the costal margin

Answer 7

FASLE - never normal to do this

Question 8

Why would the spleen grow? (5)

Answer 8

1) back pressure
2) over working red and white pulp
3) reverting to what it used to do (extramedullary haemopoiesis)
4) infiltrated by cells which shouldn’t be there eg cancer
5) infiltrated by other material

Question 9

What are the three different types of splenomegaly?

Answer 9

Massive
Moderate
Mild

Question 10

Wheat is hypersplenism?

Answer 10

Pancytopenia or thrombocytopenia can occur due to pooling of blood in enlarged spleen

Question 11

True or false: splenic rupture can lead to a haematoma which can then lead to anaemia

Answer 11

TRUE

Question 12

What is hyposplenism?

Answer 12

Lack of functioning splenic tissue

Question 13

What are the causes of hyposplenism?

Answer 13

Splenectomy
Sickle cell disease
Coeliac disease

Question 14

Which encapsulated organisms increase the risk of patients with hyposplenism developing overwhelming sepsis?

Answer 14

Pneumococcus
Haemophilus influenzae
Meningococcus

Question 15

What is cytopenia?

Answer 15

Reduction in number of blood cells

Question 16

Define anaemia

Answer 16

Low RBC count

Question 17

Define leucopenia

Answer 17

Low WBC count

Question 18

Define neutropenia

Answer 18

Low neutrophil count

Question 19

Define thrombocytopenia

Answer 19

Low platelet count

Question 20

Define pancytopenia

Answer 20

Low RBCs, WBCs and platelets

Question 21

Define erythrocytosis

Answer 21

High RBC count

Question 22

What does a suffix of cytosis/philia mean?

Answer 22

Increase in number of blood cells

Question 23

What is the commonest WBC?

Answer 23

Neutrophil

Question 24

How many segments does a neutrophil usually have and when can this number increase?

Answer 24

3-5 segments

Increases in B12 deficiency

Question 25

What controls neutrophil maturation?

Answer 25

Hormone G-CSF

Question 26

What does the hormone G-CSF do?

Answer 26

1) increases production of neutrophils 2) decreases time to release mature cells from bone marrow 3) enhances chemotaxis 4) enhances phagocytosis and killing of pathogens

Question 27

How are patients treated to reduce neutropenic infections post-chemotherapy?

Answer 27

Self-injected GCSF hormone

Question 28

What are the causes of neutrophilia?

Answer 28

1) infection (esp bacterial) 2) tissue damage 3) acute inflammation 4) cancer 5) cytokines 6) smoking 7) metabolic/endocrine disorders 8) drugs eg steroids 9) haemorrhage 10) myeloproliferative diseases

Question 29

What are the causes of neutropenia associated with reduced production?

Answer 29

1) B12/folate deficiency 2) infiltration of bone marrow by malignancy or fibrosis 3) aplastic anaemia (empty marrow) 4) radiation 5) drugs - chemo, antibiotics etc 6) viral infection 7) congenital disorders

Question 30

What are the consequences of neutropenia?

Answer 30

1) severe life threatening bacterial infection 2) severe life threatening fungal infection 3) mucosal ulceration

Question 31

What are the causes of monocytosis?

Answer 31

Chronic inflammatory conditions Chronic infection Carcinoma Myeloproliferative disorders

Question 32

What is the lifespan of eosinophils?

Answer 32

8-12 days

Question 33

What do eosinophils do?

Answer 33

1) deal with some parasites 2) mediate allergic responses 3) phagocytosis of antigen-antibody complexes 4) mediate hypersensitivity reactions eg to drugs, in asthma, skin inflammation

Question 34

What do eosinophil granules contain?

Answer 34

Arginine, phospholipid, enzymes

Question 35

Which type of WBC is least common but largest?

Answer 35

Basophil

Question 36

What do basophils do?

Answer 36

Active in allergic reactions and inflammatory conditions

Question 37

What can lead to basophilia?

Answer 37

Immediate hypersensitivity reactions Ulcerative colitis Rheumatoid arthritis Myeloproliferative disorders

Question 38

What are the three types of lymphocytes?

Answer 38

B cells T cells Natural killer cells

Question 39

What can lead to lymphocytosis?

Answer 39

``` Viral infections Bacterial infections Stress related: MI Post splenectomy Smoking Lymphoproliferative disorders: leukaemia, lymphoma ```

Question 40

What can lead to pancytopenia?

Answer 40

1) reduced production of cells | 2) increased removal: immune destruction, splenic pooling and haemophagocytosis

Question 41

What is haemophagocytosis?

Answer 41

Chewing up of cells in bone marrow

Question 42

What is the healthy ratio of fat:cells in bone marrow?

Answer 42

50:50

Question 43

What is aplastic anaemia?

Answer 43

Pancytopenia with hypocellular bone marrow in absence of abnormal infiltrate and no increase in reticulin (fibrosis)

Question 44

What are the symptoms of pancytopenia?

Answer 44

1) Symptoms of anaemia - fatigue, dizziness, chest pain, shortness of breath 2) Symptoms of thrombocytopenia - bleeding, bruising etc 3) Symptoms of neutropenia - infection, ulcers, fevers etc 4) Symptoms of underlying cause

Question 45

Which cell has the greatest power of self-renewal compared to any other adult tissue?

Answer 45

Haemopoietic stem cell

Question 46

What are the sources of haemopoietic stem cells?

Answer 46

1) aspiration of bone marrow 2) GCSF mobilised stem cells in peripheral blood 3) umbilical cord stem cells