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

Composition of blood

A

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
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
  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
Q

Lymph node function

A

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

11
Q

Problems with blood cells list

A
  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
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
Q

Normocytic anaemia differentials

A
Chronic disease
Acute blood loss
Hemoglobinopathies
Primary marrow disorders
Combined defiencies
Haemolysis
Renal failure
26
Q

Macrocytic anaemia

A
Megaloblastic anaemia
Liver disease/ alchohol
Metabolic disorders
Marrow disorders
Reticulocytosis
Drugs
27
Q

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

A
  • 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
Q

Reticulocyte count use for

A

• Investigation of anaemia

29
Q

Reticulocytes increased indicates

A
  • RBC production appropriately increased
  • Reduced survival (Haemoloysis or bleeding)
  • LDH, Bili, blood film, haptoglobins can help distinguish
30
Q

If reticulocytes reduced

A

• Problem with production

31
Q

Peripheral blood film usefulness depends on

A

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
Q

Red cell morphology example

A

Sickle cell anaemia

33
Q

White cell morphology example

A

Dysplastic neutrophils

34
Q

Platelets morphology example

A

Abnormally large platelets

35
Q

Abnormal circulating cell example

A

Burkitts lymphoma cells

APML blasts

36
Q

FBC changes may be secondary to:

A

Physiological
Inherited
Acquired

37
Q

Physiological example

A

Pregnancy
Infancy
Ethnicity different normal ranges

38
Q

Inherited examples

A
Anaemia:
•	Hb
•	Enzyme
•	Membrane
•	Bone marrow
39
Q

Acquired examples

A
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
Q

Too many cells: Clonal/neoplastic

A
Lymphoid progenitor: 
•	ALL (immature cells)
•	CLL, Lymphomas, MM (mature cells)
Myeloid progenitor:
•	AML (immature cells)
•	Myeloproliferative disorders
41
Q

Acute leukaemias Types

A

Myeloid or lymphoid
Proliferation or immature cells
Differentiation block

42
Q

Acute leukaemias Symptoms

A

Marrow failure:

  1. anaemia
  2. Thrombocytopenia (bleeding)
  3. Infection (neutropenia)
  4. Patients have a relatively short history and are often unwell
43
Q

Myeloproiferative neoplasm Characterised by

A

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

44
Q

Myeloproiferative neoplasm Lead to

A

Cytokine independent unrestricted growth

45
Q

Myeloproiferative neoplasmPatients present

A

Often well and asymptomatic therefore incidental findings

46
Q

Myeloproiferative neoplasm Types

A

Platelets: essential thrombocytthaemia ET

Red cells: Polycythaemia, rubra Vera, PRV

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

47
Q

Myeloproiferative neoplasm Mutation associated

A

JAK2 V617F

48
Q

Primary haematological cause

A
Lymphoid clonal expansion
Lymphoproiferative – 
•	Lymphoma
•	Leukaemia
(common present with lymphocytosis or lymphadenopathy or both
49
Q

Lymphadenopathy causes

A

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
Q

Clinically divide into

A

Localized or generalized

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

51
Q

Lymphoproliferative (clonal problems

A
Leukaemia → bone marrow (acute vs chronic)
Lymphoma → LNs> bone marrow
•	Hodkins
•	Non hodkins
High grade vs low grade
52
Q

Symptomatic Myeloma: Acronym

A
CRABI
C – hypercalcaemia
R- renal dysfunction
A – anaemia
B – bone – lytic lesions, fractures, osteoporosis
I – Infection
53
Q

Symptomatic Myeloma: Asymptomatic Myeloma

A

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

54
Q

Symptomatic Myeloma: MGUS

A

<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
Q

Thrombocytopenia

A
  • 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
Q

Risk of bleeding is not based on

A
  • 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
Q

Thrombocytopaenia spurious causes

A
  • Large platelets
  • Platelet clumping
  • Fibrin strand
  • Platelet Satelitism
58
Q

Neutropenia: Definition

A

<1.5 x 109/l

59
Q

Neutropenia: African patients neutrophil numbers normal

A

<1x109/l (Physiological “ethnic” neutropenia

60
Q

Neutropenia: Risk of infection determined by

A

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

61
Q

Neutropenia: Neutropenia increases risk of

A

Bacterial
Suprative infections
Not parasitic or viral infections

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