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Flashcards in Haematology: introduction to blood cells Deck (61):
1

Composition of blood


Blood which is composed of plasma (-55%) and the cellular elements which are:
1. The erythrocytes (RBC’s)-45%
2. The Leukocytes (WBC’s) and platelets (thrombocytes) – 1%

2

Erythrocytes contain and function

Contain haemoglobin
Function in the transport of O2 and CO2

3

Centrifuged whole blood the sample

Anti-coagulated sample e.g. EDTA to chelate Ca2+

4

Normal blood cell production –


• Fetal: yolk sac
• Post natal – long bones (femur and humerus)
• Adult – axial skeleton

5

Bone Marrow

• 75% of marrow for WBC
• 25% of BM for Red cells
Erythroid/Granuocyte Ratio 1:3 (increased in consumption or loss of RBC)

6

How are cells produced?

Multi-potential hematopoietic stem cells
• Common myeloid progenitor
• Common lymphoid progenitor

7

Common myeloid progenitor produces

Thrombocytes
Erythrocytes
Mast cells
Myleblasts:
• Basophil
• Neutrophils
• Eosinphils
• Monocyte → macrophage

8

Common lymphoid progenitor produces

Natural killer cells
T lymphocytes (cell mediated immunity and also “help” B cells)
B lymphocytes ( humoralimmunity)

9

Lymphoid tissue found in


1. Bone marrow
2. Thymus
3. Tonsils and adenoids
4. Spleen
5. Lymph nodes
6. Gut associated lymphoid tissue (GALT) e.g. tonsils, appendix, payers patches
7. Lymphatic channels
8. Blood – 2% of total body lymphocytes
9. Thyroid, parotid etc.

10

Lymph node function

Act as a filter to remove bacteria, wiruses, and foreign particles

11

Problems with blood cells list

1. Myeloid or lymphoid
2. Too many cells (cythaemia, cytosis – “reactive or neoplastic/clonal)
3. Lymphadenopathy – “reactive or neoplastic”
4. Hepatosplenomegaly
5. Clonal plasma cells (Myeloma, MGUS, plasmacytoma)
6. Too many cells (cytopenia)
7. Dysfunction

12

What does the full blood count measure:

Red cells
Platelets
White cell count
WCC: differential e.g. neutrophils

13

Red cells looking at

Concentratino of haemoglobin: Hb
Red cell to plasma ratio: Hct or PCV (pack cell volume)
Cell numbers (RBC)
Cell size (MCV)
Amount of Hb/RBC (MCH, MCHC)

14

Platelet normal range

150-4000 x 109/l

15

WCC normal range

4-11 x 109/l (4-11)

16

Neutrophils range

2-7.5 x 109/l

17

Lymphocytes range

1.0-4.0 x 109/l

18

Haemoglbin

Male: 130-180 g/L
Female: 115-165 g/L

19

Haematocrit

Male: 42%-54%
Female: 38%-46%

20

RBC count

Male: 4.7-6.1 million cells/mcL
Female: 4.2-5.4 million cells/mcL

21

Haematocrit definition

Ratio of red cells to haemoglobin
Contents:
• 57% plasma
• 1% buffy coat – WBC
• 42% Hct (PCV)

22

MCV indicates and good starting point for

Mean cell volume (MCV)
Indicates the Red cell volume (size)
Normal range 80-100 fl
Good starting point for the evaluation of anaemia

23

MCV can be

Microcytic (100 fl)

24

Microcytic anaemia differentials

Iron defiency IDA
(Chronic bleeding)
Chronic disease
Thalassemias
Hemoglobinopathies
Sideroblastic anaemia

25

Normocytic anaemia differentials

Chronic disease
Acute blood loss
Hemoglobinopathies
Primary marrow disorders
Combined defiencies
Haemolysis
Renal failure

26

Macrocytic anaemia

Megaloblastic anaemia
Liver disease/ alchohol
Metabolic disorders
Marrow disorders
Reticulocytosis
Drugs

27

Mean cell haemoglobin (MCH) and Mean cell haemoglobin concentration (MCHC) reflect

• Both the MCH and MCHC reflect Hb content of RBC
• MCH – 27.0-32.0 pg. Increased on macrocytosis (Large RBC)
• MCHC – 32.0-36.0 g/dL. Increased in spehrocytosis
• Both are reduced in iron defiency and thalassaemia

28

Reticulocyte count use for

• Investigation of anaemia

29

Reticulocytes increased indicates

• RBC production appropriately increased
• Reduced survival (Haemoloysis or bleeding)
• LDH, Bili, blood film, haptoglobins can help distinguish

30

If reticulocytes reduced

• Problem with production

31

Peripheral blood film usefulness depends on

Clinical information provided on request
May direct further investigations
Asess red cell, platelet and white cell, number, size, colour, morphology
Any abnormal circulating cells?

32

Red cell morphology example

Sickle cell anaemia

33

White cell morphology example

Dysplastic neutrophils

34

Platelets morphology example

Abnormally large platelets

35

Abnormal circulating cell example

Burkitts lymphoma cells
APML blasts

36

FBC changes may be secondary to:

Physiological
Inherited
Acquired

37

Physiological example

Pregnancy
Infancy
Ethnicity different normal ranges

38

Inherited examples

Anaemia:
• Hb
• Enzyme
• Membrane
• Bone marrow

39

Acquired examples

Infection (viral, bacterial, protozoal)
Neoplastic (haem or non haem)
Vascular (bleeding, infarction)
Inflammatory, Immune
Trauma (e.g. surgery)
Endocrine 9thyroid, cortisol, pituitary)
Drugs
Metabolic (B12, folate, iron, liver, renal, alcohol)
Degenerative (MDs), Dietary

40

Too many cells: Clonal/neoplastic

Lymphoid progenitor:
• ALL (immature cells)
• CLL, Lymphomas, MM (mature cells)
Myeloid progenitor:
• AML (immature cells)
• Myeloproliferative disorders

41

Acute leukaemias Types

Myeloid or lymphoid
Proliferation or immature cells
Differentiation block

42

Acute leukaemias Symptoms

Marrow failure:
1. anaemia
2. Thrombocytopenia (bleeding)
3. Infection (neutropenia)
4. Patients have a relatively short history and are often unwell

43

Myeloproiferative neoplasm Characterised by

Excessive proliferation of terminally differentiated myeloid cells (normal differentiation) – somatic acquired mutations in haemopoitic stem cells

44

Myeloproiferative neoplasm Lead to

Cytokine independent unrestricted growth

45

Myeloproiferative neoplasmPatients present

Often well and asymptomatic therefore incidental findings

46

Myeloproiferative neoplasm Types

Platelets: essential thrombocytthaemia ET

Red cells: Polycythaemia, rubra Vera, PRV

Granulocytes: Chronic myeloid, leukaemia, Ph+ BCR/ABL +

47

Myeloproiferative neoplasm Mutation associated

JAK2 V617F

48

Primary haematological cause

Lymphoid clonal expansion
Lymphoproiferative –
• Lymphoma
• Leukaemia
(common present with lymphocytosis or lymphadenopathy or both

49

Lymphadenopathy causes

Lymphoma
Infection (viral e.g. HIV/EBV, bacterial e.g. TB)
Neoplatic (haem or non haem e.g. Ca)
Inflammatory (e.g. sarcoid, SLe)

50

Clinically divide into

Localized or generalized
→ if localized look for cause (infection, inflammation, malignancy) – need some idea which lymphoid groups drain what.

51

Lymphoproliferative (clonal problems

Leukaemia → bone marrow (acute vs chronic)
Lymphoma → LNs> bone marrow
• Hodkins
• Non hodkins
High grade vs low grade

52

Symptomatic Myeloma: Acronym




CRABI
C – hypercalcaemia
R- renal dysfunction
A – anaemia
B – bone – lytic lesions, fractures, osteoporosis
I – Infection

53

Symptomatic Myeloma: Asymptomatic Myeloma

No CRABI
AND ether
>-10% plasma cell sin bone marrow
OR > 30 g/ paraprotein

54

Symptomatic Myeloma: MGUS

<30 g/l paraprotein
AND no CRABI
1% per year progress to Myeloma. More likely. More likely if high level PP, non IgG (IgM, IgA, IgE or IgD) and abnormal SFLC

55

Thrombocytopenia

• Repeat the test, look at previous results and ask for a blood film.
• Take a careful drug history
• Risk factors for HIV and hepatitis C
• If a patient is well, has no other abnormal clinical or laboratory findings then likely immune thrombocytopenia is the commonest cause

56

Risk of bleeding is not based on

• Platelet count alone; also consider age, co-morbidity, mandated anticoagulation, risk of trauma and any need for surgery
• Spontaneous bleeding/bruising unusual unless platelets <30 x 109/l

57

Thrombocytopaenia spurious causes

• Large platelets
• Platelet clumping
• Fibrin strand
• Platelet Satelitism

58

Neutropenia: Definition

<1.5 x 109/l

59

Neutropenia: African patients neutrophil numbers normal

<1x109/l (Physiological “ethnic” neutropenia

60

Neutropenia: Risk of infection determined by

Severity and cause of neutropenia
Mild 1-1.5
Moderate 0.5-1
Severe <0.5

61

Neutropenia: Neutropenia increases risk of

Bacterial
Suprative infections
Not parasitic or viral infections

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