Haematology: introduction to blood cells Flashcards
1
Q
Composition of blood
A
Blood which is composed of plasma (-55%) and the cellular elements which are:
- The erythrocytes (RBC’s)-45%
- The Leukocytes (WBC’s) and platelets (thrombocytes) – 1%
2
Q
Erythrocytes contain and function
A
Contain haemoglobin
Function in the transport of O2 and CO2
3
Q
Centrifuged whole blood the sample
A
Anti-coagulated sample e.g. EDTA to chelate Ca2+
4
Q
Normal blood cell production –
A
- Fetal: yolk sac
- Post natal – long bones (femur and humerus)
- Adult – axial skeleton
5
Q
Bone Marrow
A
• 75% of marrow for WBC
• 25% of BM for Red cells
Erythroid/Granuocyte Ratio 1:3 (increased in consumption or loss of RBC)
6
Q
How are cells produced?
A
Multi-potential hematopoietic stem cells
• Common myeloid progenitor
• Common lymphoid progenitor
7
Q
Common myeloid progenitor produces
A
Thrombocytes Erythrocytes Mast cells Myleblasts: • Basophil • Neutrophils • Eosinphils • Monocyte → macrophage
8
Q
Common lymphoid progenitor produces
A
Natural killer cells T lymphocytes (cell mediated immunity and also “help” B cells) B lymphocytes ( humoralimmunity)
9
Q
Lymphoid tissue found in
A
- Bone marrow
- Thymus
- Tonsils and adenoids
- Spleen
- Lymph nodes
- Gut associated lymphoid tissue (GALT) e.g. tonsils, appendix, payers patches
- Lymphatic channels
- Blood – 2% of total body lymphocytes
- Thyroid, parotid etc.
10
Q
Lymph node function
A
Act as a filter to remove bacteria, wiruses, and foreign particles
11
Q
Problems with blood cells list
A
- Myeloid or lymphoid
- Too many cells (cythaemia, cytosis – “reactive or neoplastic/clonal)
- Lymphadenopathy – “reactive or neoplastic”
- Hepatosplenomegaly
- Clonal plasma cells (Myeloma, MGUS, plasmacytoma)
- Too many cells (cytopenia)
- Dysfunction
12
Q
What does the full blood count measure:
A
Red cells
Platelets
White cell count
WCC: differential e.g. neutrophils
13
Q
Red cells looking at
A
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
Q
Platelet normal range
A
150-4000 x 109/l
15
Q
WCC normal range
A
4-11 x 109/l (4-11)
16
Q
Neutrophils range
A
2-7.5 x 109/l
17
Q
Lymphocytes range
A
1.0-4.0 x 109/l
18
Q
Haemoglbin
A
Male: 130-180 g/L
Female: 115-165 g/L
19
Q
Haematocrit
A
Male: 42%-54%
Female: 38%-46%
20
Q
RBC count
A
Male: 4.7-6.1 million cells/mcL
Female: 4.2-5.4 million cells/mcL
21
Q
Haematocrit definition
A
Ratio of red cells to haemoglobin Contents: • 57% plasma • 1% buffy coat – WBC • 42% Hct (PCV)
22
Q
MCV indicates and good starting point for
A
Mean cell volume (MCV)
Indicates the Red cell volume (size)
Normal range 80-100 fl
Good starting point for the evaluation of anaemia
23
Q
MCV can be
A
Microcytic (100 fl)
24
Q
Microcytic anaemia differentials
A
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
