Haemotology

Question 1

what are the components of blood?

Answer 1

55% Plasma - water, proteins, other solutes

45% Cells - red blood cells
white blood cells (lymphocytes, granulocytes, monocytes)
platelets

Question 2

What is the name of blood cell production?

Where are blood cells made?

Answer 2

Haematopoiesis

Before birth by yolk sac and then spleen/liver. By adulthood it is mainly axial skeleton (vertebrae and pelvis) in bone marrow

Question 3

What percentage of marrow production is white cells/red cells?

Precursor for platelets?

Answer 3

75% white cells
25% red cells

Megakaryocytes are platelet producing cells

Question 4

What is the stem cell which gives rise to all other blood cells?

What are the two lineages of blood cells and which cells do they produce?

Answer 4

Haematopoeitic stem cells (HSC)

Myeloid: erythrocytes, platelets, granulocytes (eosinophils, neutrophils, basophils), monocytes (macrophages)
Lymphoid: Mature in thymus - T cell, B cell, NK cells

Question 5

Which growth factors are used to stimulate differentiation of erythrocytes? Platelets? Granulocytes?

Answer 5

Erythrocytes - erythropoietin (EPO) produced by the kidney is response to anaemia or hypoxia

Platelets - thrombopoietin (TPO) produced by liver

Granulocytes - granulocyte colony stimulating factor (G-CSF)

Question 6

What is the MCV (mean cell volume) and what is it useful for measuring?

Answer 6

Mean cell volume measures the red cell volume (size)
Normal range (normocytic) is 80-100fL. 
Starting point for evaluation of anaemia

Question 7

Cause of:
microcytic anaemia
macrocytic anaemia

Answer 7

microcytic anaemia- small cells, cause: iron deficiency

Macrocytic - large cells, cause: folate deficiency

Question 8

Reticulocyte count

Answer 8

‘RBC to be’
increased reticulocyte numbers = increased RBC production

If reticulocytes are reduced, then problem with production (anaemia)

Question 9

Describe plasma cells.

Is reactive increase clonal or polyclonal?

Answer 9

Part of humoral immunity. Plasma cells produce antibodies or immunoglobulins. Immunoglobulins have a constant and variable reigon.

Reactive increase is POLYCLONAL

Question 10

What is polycythaemia and what are the types?

Answer 10

Increased Hb and Hct.

Relative polycythaemia: Due to decrease in plasma. No change in absolute RBC mass but propotionate increase. Dehydration, diuretics, alcohol

Absolute polycythaemia: Increase in RBC mass

Question 11

Causes of primary and secondary polycythaemia

Answer 11

Primary (neoplastic): Polycythaemia ruba vera, myeloproliferative disorder, JAK2 mutated, EPO suppressed

Secondary: JAK2 unmutated, EPO increased (hypoxia, smoking, high altitude, tumours)

Question 12

Causes of Thrombocytosis (increased platelets)

Answer 12

1. Reactive: 
Trauma (e.g. by surgeon)
Infection
Inflammation
Splenectomy 
Iron deficiency 
Non-haemotlogical malignancy

2. Clonal
Myeloproliferative disorders (MPN)

3. Spurious (FBC machine counts something else as platelets)

Question 13

Causes of Leucocytosis (increased white cells)

Answer 13

1. Reactive
Trauma (e.g. by surgeon)
Smoking
Infection
Inflammation
Non-haemotological malignancy
splenectomy 
steroids

2. Clonal
   lymphoproliferative, myeloproliferative

Question 14

Causes of lymphadenopathy

Answer 14

Infection: viral (HIV/EBV) or bacterial (TB)
Non haemotological cancer
Inflammatory (Sarcoid, SLE)
Lymphoproliferative neoplasms

Question 15

Acute Leukaemia

Types? presentation?

Answer 15

AML: acute myeloid leukaemia
ALL: acute lymphoblastic leukaemia

Proliferation of immature cells

Present with bone marrow failure i.e anemia, thrombocytopaenia (bleeding), neutropenia (infection)

Question 16

Myeloproliferative Neoplasms

• characterised by?
• cause?
• result?

Types for granulocytes? red cells? Platelets?

Answer 16

Characterised by excessive proliferation of terminally differentiated myeloid cells (cells look normal)

Caused by somatic mutation of haematopoetic stem cells.

Leads to cytokine independent growth

Granulocytes - chronic myeloid leukaemia

Red cells - ruba vera polycythaemia

Platelets - Essential thrombocythaemia

Question 17

Lymphoproliferative neoplasms

Types?

Answer 17

B cell or T cell

Leukaemia: bone marrow>lymph nodes

Lymphona: lymph nodes>bone marrow
Hodgkin’s lymphoma
Non Hodgkin’s lymphoma

Question 18

Clonal plasma cells (neoplastic plasma cells)
How do the not present?
What does it cause?

Answer 18

Does not present with peripheral blood plasmacytosis or lymphadenopathy (cells accumulate in bone marrow)

Plasma cells produce abnormal, ineffective immunoglobulin which leads to decreased bone marrow function, destruction of bone tissue and end organ damage

Question 19

What is shown in an abnormal serum electophoresis result for myeloma?

Answer 19

M spike

Question 20

What are symptoms of Myeloma?

Answer 20

CRABI
C - hypercalcaemia 
R- renal dysfuntion
A- anaemia
B- bone (leisons, osteoporosis, fractures
I - infection

Question 21

Thrombocytopenia (low platelets) causes

Answer 21

Immune - immune thrombocytopenia (lymphoproliferative HIV or hepatitis C infection)

Drugs - heparin, anticonvulsants, chemotherapy, alcohol, quinine

Infections

Marrow dysfunction - dysplasia, infiltration, aplasia, fibrosis

Liver disease

Splenomegaly

Microangiopathic haemolysis

Preganancy specific- gestational, HELLP syndome

Question 22

Neutropenia (low neutrophils) causes

Answer 22

Drugs - antipsychotics, anticonvulsants, chemotherapy, omeprazole

Infections

Marrow dysfunction - dysplasia, infiltration, aplasia, fibrosis

Immune

Splenomegaly