Haematology Flashcards

1
Q

What is Haemopoeisis?

A

The physiological developmental process that gives rise to cellular components of blood. (2 lineages: myeloid & lymphoid)

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2
Q

What are the origins of haemopoeisis?

A

Day 27: at the Aorto-Gonado-Mesonephros

Day 40: disappears (migration of these haematopoietic stem cells to the foetal liver)

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3
Q

Examples of Myeloid cells?

A

Granulocytes (wbc)
Erythrocytes (rbc)
Platelets

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4
Q

Examples of Lymphoid cells?

A

B-Lymphocytes (wbc)

T-Lymphocytes (wbc)

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5
Q

What does the term ‘Reference Range’ mean in clinical practice?

A

The set of values for a given test that incorporates 95% of the normal population.

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6
Q

What does Sensitivity mean in clinical practice?

A

The proportion of abnormal results correctly classified by the test. The ability to DETECT a TRUE ABNORMALITY. =TP/(TP+FN)

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7
Q

What does Specificity mean in clinical practice?

A

The proportion of normal results correctly classified by the test. The ability to EXCLUDE an ABNORMAL RESULT in a HEALTHY PERSON. =TN/(TN+FP)

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8
Q

(WBC)…

1) Eosinophilia? (^ numbers)
2) Basophilia? (^ numbers)
3) Monocytosis? (^ numbers)

A

1) Eosinophilia… due to= parasitic infection, allergies
2) Basophilia (part of primitive immune system)… due to= CML
3) Monocytosis (phagocytic & antigen presenting)… due to= TB

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9
Q

(WBC)…

4) Lymphocytosis? (^ numbers)
5) Lymphopenia? (decreased numbers)
6) Plasmacytosis?

A

4) Lymphocytosis… due to= glandular fever, CLL
5) Lymphopenia… due to= post-bone marrow transplant
6) Plasmacytosis… due to= infection & myeloma

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10
Q

What is myelodysplastic syndrome?

A

Mutated stem cells produce a clone of abnormal cells that replace normal haemopoiesis= abnormal cells, bone marrow is CELLULAR.
Manifestations vary–> chronic anaemia, ends in acute myeloid leukaemia.

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11
Q

Treatment of myelodysplastic syndrome?

A

Transfusions
Lenalidomide
Azacytidine

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12
Q

What parts of the coagulation cascade can be assayed?

A

Prothrombin Time
Activated Partial Thromboplastin Time
Thrombin Time

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13
Q

What is Microcytic Hypochromic anaemia caused by?

A

(anaemia of chronic disease)

  • Iron Deficiency
  • Thalassaemia
  • Lead Poisoning
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14
Q

What is Normocytic Normochromic anaemia caused by?

A

(many haemolytic anaemias, anaemia of chronic disease)

  • After acute blood loss
  • Renal disease
  • Bone Marrow failure
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15
Q

What is Macrocytic Megaloblastic anaemia caused by?

A

Vit B12 or folate deficiency

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16
Q

What is Macrocytic Non-megaloblastic anaemia caused by?

A

Alcohol, liver disease, hypothyroidism

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17
Q

The tissue oxygenation depends on what?

A

Hb concentration
The oxygen saturation of Hb
The affinity of Hb to oxygen
The oxygen requirements of tissues

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18
Q

Why would you transfuse with Fresh Frozen Plasma?

A

Coagulopathy with bleeding/surgery, massive haemorrhage

CONTRAINDICATIONS= Warfarin reversal or replacement of a single factor dificiency

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19
Q

Why would you transfuse with Platelets?

A

Treatment of bleeding due to severe thrombocytopenia (low platelets). Prevent bleeding.
CONTRAINDICATIONS= Heparin-induced thrombocytopenia & thrombosis.

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20
Q

What classifies as a delayed transfusion complication? What are the clinical manifestations?

A

Onset 3-14 days after RBC transfusion
Due to immune IgG antibodies against RBC antigens
Clinical= Fatigue, fever, jaundice.

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21
Q

What is an Immunological Delayed Transfusion reaction?

A
  • Transfusion-associated graft-versus-host disease

- Post transfusion purpura

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22
Q

What is a Non-immunological Delayed Transfusion reaction?

A

Transfusion Transfusion Infection (TTI)

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23
Q

What is an Immunological Acute Transfusion reaction?

A

Acute haemolytic transfusion reaction
ABO incompatability
Allergic/ anaphylactic reaction
TRALI (transfusion-related acute lung injury)

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24
Q

What is a Non-immunological Acute Transfusion reaction?

A

Bacterial contamination
TACO (transfusion associated circulatory overload)
Febrile non-haemolytic transfusion reaction

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25
Q

What is crossmatching?

A

It is for compatibility. Patients plasma is mixed with donor RBC to see if a reaction occurs.

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26
Q

What is a transfusion threshold (trigger)?

A

How we determine the ideal Hb concentration for different patients. It is the lowest concentration of Hb that is not associated with symptoms of anaemia.

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27
Q

What are some mechanisms of adaption to anaemia?

A
  • Increased cardiac output
  • Increased cardiac artery blood flow
  • Increased oxygen extraction
  • Increase erythropoeisis
  • Increase RBC 2,3 DPG
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28
Q

Why is there increased oxygen extraction in chronic anaemia?

A

Due to the rise in levels of 2,3 DPG becuase the kidneys respond to hypoxia by increasing the production of erythropoeitin.

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29
Q

In what type of anaemia is the respiration rate more markedly increased?

A

Acute anaemia

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30
Q

What is TRALI?

A

Transfusion Related Acute Lung Injury.
Activated WBC lodge in pulmonary capillaries. Release substances that cause endothelial damage and capillary leak.
CRITERIA: sudden onset of ‘Acute Lung Injury’ occurring within 6 hours of transfusion.

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31
Q

What is TACO?

A

Transfusion-Associated Circulatory Overload.

Signs/symptoms= sudden dyspnea, orthopnoea, tachycardia, hypertension.

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32
Q

What are some allergic reactions associated with blood transfusion?

A
  • Urticarial Rash (often not severe)

- Anaphylaxis (severe, life threatening acute reaction)

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33
Q

Difference between TRALI and TACO?

  • Type of component
  • BP
  • Temp
  • Diuretics
  • Fluid loading
A

TRALI: Usually platelets/plasma. TACO: Any
TRALI: BP reduced TACO: Often raused
TRALI: Temp raised TACO: Temp normal
TRALI: Diuretics worsen TACO: Diuretics improve
TRALI: Fluid improves TACO: Fluid worsens

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34
Q

What are Febrile non-haemolytic transfusion reactions (FNHTR) due to?

A

FNHTR are due to cytokines or other biologically active molecules that accumulate during storage of blood components.

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35
Q

What is von Willebrand Disease?

A
  • Autosomal dominant inheritance (most common heritable bleeding disorder
  • Variable reduction in Factor VIII levels
  • Treatments: Antifibrinolytics (tranexamic acid), DDAVP (type 1 vWD), Factor concentrates with vWF
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36
Q

What are the Haemophilias?

A

Haemophilia A= Factor VIII deficiency
Haemophilia B= Factor IX deficiency (both intrinsic factors)
X-linked recessive disorders. ~30% cases are new mutations. Expressed in males, carried by females.

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37
Q

What are some treatments of Haemophilia?

A

-Replacement of missing clotting protein
-DDAVP
-Antifibrinolytics
(Complications= inhibitor development)

38
Q

2 examples of haemoglobinopathies?

A

1) Structural Hb Variants, eg)Hb S (sickle). Usually single base substitution.
2) Thalassaemias (alpha/beta)- change in globin chain expression leads to reduced rate of synthesis of normal globin chains. (pathology is due to imbalance of alpha/beta chain production)

39
Q

What are the components of the different types of globin chains? (all normal globins have 2 Alpha and 2 non-alpha chains)

A
Hb-A = 2alpha/2beta  =>95%
Hb-B = 2alpha/2gamma =<3.5%
Hb-A2 = 2alpha/2delta =<1%
40
Q

Describe the genetic control of globin chains?

A

Chromosome 16 –> alpha chains

Chromosome 11 –> gamma, delta and beta chains

41
Q

What are the 5 physiological changes that occur in the blood in pregnancy?

A

1) Anaemia & Macrocytosis
2) Thrombocytopenia (not enough platelets in blood)
3) Neutrophilia
4) Increased procoagulant factors
5) Decreased Fibrinolysis

42
Q

Why does anaemia and macrocytosis occur in pregnancy?

A
  • Plasma volume expands by 50%, RBC mass expands by 25%
  • Haemodilution occurs, maximally at 32 weeks (a decrease in the proportion of RBC relative to plasma)
  • Iron and folic acid requirements increase
43
Q

What are some of the main causes of thrombocytopenia in pregnancy?

A

Severe folate deficiency, gestational, pre-eclampsia & HELLP syndrome.
(coincidental causes= bone marrow infiltration/ hypoplasia, viral, sepsis, hypersplenism)

44
Q

Why is pregnancy a pro-thrombotic state?

A
  • Evidence of platelet activation
  • Increase in many procoagulant factors
  • Reduction in fibrinolysis
  • Rise in markers of thrombin generation
45
Q

What is Sickle Cell Disease? (homozygous Hb S/S)

A
Valine substituted for glutamine at position 6 of the beta-globin chain
Sickle Hb (Hb-S) polymerises at low oxygen tensions to form long fibrils ('tactoids') which distort the RBC membrane--> sickle shape
46
Q

What are some acute complications of Sickle Cell Disease?

A

Vaso-occlusive crisis
Septicaemia
Aplastic crisis
Sequestration crisis (spleen, liver)

47
Q

What are some chronic complications of Sickle Cell Disease?

A
  • Hyposplenism (due to infarction + atrophy of spleen)
  • Renal Disease (medullary infarction, tubular damage, glomerular)
  • Leg ulcers/ osteomyelitis/ gall stones/ retinotherapy
48
Q

What is alpha-Thalassaemia?

A

Typically results from deletions involving HBA1 & HBA2 genes.
Hb Bart syndrome (most severe form) results from loss of all 4 alpha-globin alleles.

49
Q

What is beta-Thalassaemia?

A

Reduced rate of production of beta-globin chains.

  • Carriers (Thalassaemia Minor) are clinically normal. Blood picture resembles iron deficiency.
  • Homozygotes (Thalassaemia Major) can die of severe anaemia. Blood films abnormal, nucleated RBC. Short stature & distorted limb growth. Enlarged liver/spleen = ‘extramedullary haemopoiesis’
50
Q

Treatment of beta-Thalassaemia major?

A

Transfusion (suppresses marrow RBC production & prevents skeletal deformity & liver/spleen enlargement)

51
Q

What are the complications of transfusion in the treatment of beta-Thalassaemia major?

A

The body has no excretory mechanism for iron, possibility of severe iron overload & toxicity…
…gonads/hypothalamus= failure of puberty, growth failure.
…pancreas= diabetes
…heart= dilated cardiomyopathy & heart failure
…liver= cirrhosis

52
Q

What is used to combat the complications of transfusion for beta-Thalassaemia major?

A

To prevent death from iron overload, patients are started on Iron Chelation therapy from age 2 to promote excretion of iron in urine/faeces…

  • –Desferrioxamine
  • –New oral iron chelators include deferiprone & Deferasirox
53
Q

What is Myeloma (malignant disorder of clonal plasma cells) preceded by?

A

Asymptomatic MGUS (M protein in blood). Can cause amyloidosis (accumulation of proteins in the form of abnormal, insoluble fibres known as amyloid fibrils)

54
Q

What is the connection between myeloma and the kidneys?

A

50% have renal insufficiency at some point

External factors= renal vein thrombosis, bisphosphonates, hypercalcaemia, dehydration.

55
Q

What are the symptoms of hypercalcaemia?

A

Constipation, anorexia, constipation.

56
Q

What are the 4 stages of B-cell differentiation? (process of naive B-cell blasts becoming either plasma or memory B-cells)

A

1) Proliferation
2) Immunoglobulin somatic hypermutation and class switch.
3) Selection
4) Differentiation

57
Q

Describe PROLIFERATION (first stage of B-cell differentiation)

A

Following antigen stimulation, B cells differentiate into centroblasts, which accumulate in the dark zone of GC (highly proliferative).

58
Q

Describe IMMUNOGLOBULIN SOMATIC HYPERMUTATION (second stage of B-cell differentiation)

A
Somatic hypermutation of Ig V-region genes of centroblasts occurs within the GC, increases intraclonal diversity. 
Centroblasts mature to centrocytes (in light zones of GC). Here, heavy chain class switch occurs to alter Ig consistancy.
59
Q

Describe SELECTION (third stage of B-cell differentiation)

A

If the centrocytes Ig mutation results in an increased affinity then the antigen can be processed and presented to T cells (rescued from apoptosis).

60
Q

Describe DIFFERENTIATION (last stage of B-cell differentiation)

A

Post GC requires inactivation of BCL6 (the regulator) & downregulating the myc gene.

61
Q

What is a mechanism that is affected by an inactivated BCL6 (the regulator)?

A

BCL6 has an inhibitory effect on BLIMP1. So when BCL6 us downregulated, BLIMP1 is upregulated. (this represses PAX5= plasma cell differentiation)

62
Q

What are the 4 polypeptide chains held together by in immunoglobulins?

A

Covalent disulphide bonds

63
Q

What is Solitary Plasmacytoma with minimal bone marrow involvement? (one presentation of myeloma)

A

Localised build up of abnormal plasma cells (in bone or soft tissue). Many go on to develop myelomas.

64
Q

What is the IMWG Diagnostic criteria for Myeloma?

A
  • Clonal BM plasma cells >10%, or Plasmacytoma

- AND any one or more of: CRAB features, MDEs (myeloma-defining events)

65
Q

What are CRAB features?

A
C= hypercalcaemia
R= renal insufficiency
A= anaemia
B= bone lesions
66
Q

What is Hodgkin Lymphoma associated with?

A

Ebstein-Barr Virus and HIV

67
Q

What is Hodgkin Lymphoma characterised by?

A

(a neoplastic disorder of neoplastic lymphocytes) characterised by Hodgkin Reed-Sternberg (HRS) cells within a cellular infiltrate of non-malignant inflammatory cells eg) eosinophils.

68
Q

Example of a)low grade, and b)high grade Non-Hodgkin Lymphoma?

A

a) low grade= Follicular Lymphoma

b) high grade= Burkitt Lymphoma

69
Q

What is Follicular Lymphoma characterised by and the genetics behind it?

A

Characterised by slowly enlarging lymph nodes.
Acquired chromosomal translocation - t(14;18)- leading to overexpression of the bcl-2 protein. This confers a survival advantage to the neoplastic lymphoid cells by inhibiting apoptosis.

70
Q

What is Chronic Lymphocytic Leukaemia (CLL)?

A

A malignant disorder of the B-cells (most common type of leukaemia in UK)

71
Q

Different presentations of CLL?

A

Some patients can remain asymptomatic for months/years, 17p deletion can influence prognosis. Presentation ranges from findings of lymphocytes, to widespread lymphadenopathy, splenomegally, bone marrow failure.

72
Q

What is Ritcher’s Transformation?

A

Rare complication of CLL, acute onset of symptoms and poor prognosis.

73
Q

What are some infections that occur in Acute Myeloid Leukaemia?

A
  • Staphylococcus aureus infection of the orbit
  • Strep. faecalis & E.coli causes perianal infection
  • Haemorrhagic ecchymoses
  • Gum hypertrophy
74
Q

What is an infection that occur in Acute Lymphoblastic leukaemia?

A

Oral candida

75
Q

What are the three favourable risk groups in cytogenics in AML?

A

t(15;17), t(8;21), inv(16)

The Philadelphia chromosome t(9;22) Translocation confers a poor prognosis also.

76
Q

What are 3 treatments of Sickle Cell Disease?

A

1- Transfusions
2- Hydroxycarbamide (^ HbF)
3- Bone marrow transplant (curative)

77
Q

(paediatric haematology)… What are RBC like at birth?

A

Children: 55-65% Hb-F at birth

Larger RBC and higher proportion of blood made up of cells.

78
Q

(paediatric haematology)… What immunoglobulins cross the placenta, and what are present in breast milk?

A

IgG crosses the placenta

Breast Milk: IgA, IgD, IgE, IgG, IgM

79
Q

When do children start producing antibodies?

A

2-3/12 months.

Make satisfactory immune response by 6/12 months.

80
Q

What clotting factors are present at birth?

A

Coagulation proteins dont cross the placenta effectively.

Only fibrinogen, FV, FVIII normal at birth.

81
Q

What is a foetus’ Vit. K like?

A

Foetal Vit K is 10% of mother (so there could be haemorrhagic disease of newborn).
Therefore needs routine neonatal Vit K
WARFARIN IS TERATOGENIC

82
Q

What is hereditary spherocytosis?

A

(congenital) A membrane defect, can be seen on peripheral blood smear.
(major complications= aplastic or megaloblastic crisis, hemolytic crisis, cholecystitis)
Splenectomy is the standard treatment.

83
Q

In acquired disorders of haemostasis, how can you tell if there is a deficiency or inhibitor?

A

Significant correction= deficiency

No correction= inhibitor

84
Q

What are some causes of Vit K deficiency?

A

Obstructive Jaundice (it is a fat soluble vitamin and so need to be able to absorb fats- bile salts)
Prolonged nutritional deficiency
Broad spectrum antibiotics
Neonates

85
Q

What is Disseminated Intravascular Coagulation (DIC)?

A

Microvascular thrombosis: tissue ischaemia and organ damage.
Activation of fibrinolysis.
Causes: sepsis, obstetric complications, trauma/tissue necrosis, (chronic: malignancy, end stage liver disease, obstetric,)

86
Q

What is management of DIC?

A

Treat underlying cause… antibiotics, obstetric intervention, chemotherapy if tumour.

87
Q

What are the different properties of LMWH (low molecular weight heparin) vs UH (unfractioned heparin)?

A

LMWH: Higher ratio of anti-Xa to anti-IIa activity
Improved bioavailability
Longer half-life allowing once daily administeration
More predictable anticoagulant response

88
Q

What may B12 deficiency result in?

A

(nutritional= vegans) Results in gastric problems (pernicious anaemia), small bowel problems (Crohns, jejunal diverticulosis).
Features common to B12/folate deficiency: megaloblastic anaemia, mild jaundice, glossitis, anorexia, sterility.

89
Q

What is SACDC?

A

Subacute combined degeneration of the cord.
Due to severe B12 deficiency- demyelination of dorsal & lateral columns, peripheral nerve damage.
Presents as: peripheral neuropathy, numbness and distal weakness, dementia.

90
Q

What are the factor deficiencies in Haemophilia A and B?

A

Haemophilia A= Factor VIII deficiency

Haemophilia B= Factor IX deficiency

91
Q

What is Factor V Leiden?

A

(most common familial thrombophilia) Homozygotes 30-50 fold increased risk for venous thrombosis.
APC resistance is associated with majority of cases, with a single point mutation in Factor V gene. Arg is replaced by Gln (so FV relatively resistant to cleavage by APC)