blood cell abnormalities

Question 1

Why does leukaemia occur?

Answer 1

Mutations in oncogenes or tumour suppressor genes lead to cell growth/survival advantage.
clone replaces normal cells

Question 2

abnormal behaviour of the rebellious leaukaemic clone:

Answer 2

Growth independent of growth factors
Continued proliferation without maturation
Failure to undergo apoptosis

Question 3

4 leukaemia types

Answer 3

Acute lymphoblastic leukaemia (ALL)
(Infancy)

Acute myeloid leukaemia (AML)
(Late middle/old age)

Chronic myeloid leukaemia (CML)

Chronic lymphoid leukaemia (CLL)

Question 4

Acute leukaemia:
Where mutation occurs/ nature of mutation
Result of mutation

Answer 4

Acute leukaemia - mutations in genes encoding transcription factor.
Result:
abnormal maturation + continued proliferation = blast cell accumulation (lymphoblasts/myeloblasts)

Question 5

Chronic myeloid leukaemia:

Nature of mutation:

Answer 5

CML: mutation involves activation of signalling pathways within cell
Result: cells proliferate without growth factors.
Maturation still occurs, mature end cells able to function. Impairment of physiological process therefore less than in acute leukaemia s

Question 6

Why CHRONIC myeloid leukaemia has less impairment of normal physiological processes than acute

Answer 6

Maturation still occurs. Mature end cells still able to function.

Question 7

Directs effects of proliferation of leukaemic cells

Answer 7

Bone pain
Hepatomegaly
Splenomegaly
Lymphadenopathy (swollen lymph nodes

Question 8

InDirects effects of leukaemic cell proliferation

Answer 8

Fatigue, lethargy, pallor (anaemia)
Fever & infection (neutropenia)
Bruising & petechiae (thrombocytopenia)
Bone pain (bone marrow expansion)
Abdominal enlargement (hepatosplenomegaly)
Lumps & swelling (lymphadenopathy)

Question 9

Essential investigations

Answer 9

Full blood count
Blood film
Flow cytometry

Question 10

Mechanisms that result in anaemia

Answer 10

Reduced production of red cells by bone marrow
Loss of blood
Reduced survival of red cells in circulation (haemolysis)
Increases pooling of red cells in enlarged spleen

Question 11

Instruments used to identify Microcystic anaemia

Answer 11

Microscope- to observe blood film: RBC - small & hypochromic

Automated blood cell counter - measures mean cell volume

Question 12

Common causes of microcytosis

Answer 12

Reduced synthesis of haemoglobin:

Iron deficiency anaemia
Anaemia of chronic disease
=> reduced synthesis of haem

Thalassaemia
=> reduced synthesis of globin

Question 13

Causes of iron deficiency

Answer 13

Increased blood loss
Insufficient intake
Increases requirements

Question 14

Causes of iron deficiency:

Examples of increased blood loss

Answer 14

Menstrual (menorrhagia)
Hookworms
Gastrointestinal bleeding (silent/asymptomatic)

Question 15

Causes of iron deficiency:

Examples of insufficient intake

Answer 15

Dietary- vegetarianism
Malabsorption
- coeliac disease (gluten induced enteropathy)
-H.pylori gastritis

Question 16

Causes of iron deficiency:

Increased requirements

Answer 16

Pregnancy

Infancy

Question 17

3 stages of iron depletion

Hint: DDA

Answer 17

Depletion: Storage iron reduced or absent
Deficiency: Low serum iron & transferrin saturation
Anaemia: Low haemoglobin & haematocrit

Question 18

Iron deficiency anaemia; clinical features

Answer 18

• Pallor, fatigue, breathlessness
• Impaired intellectual development in children
• koilonchia (nails)
• angular Cheilitis (around mouth)

Question 19

Anaemia of chronic disease: what TYPE of patients are at risk?

Answer 19

Patients who are already unwell, usually with an inflammatory aspect to their underlying disease

Question 20

Anaemia of chronic disease:

Causes

Answer 20

Rheumatoid arthritis
Autoimmune disease
Malignancy
Kidney  disease
Infections such as TB or HIV

Question 21

Why does chronic disease lead to people becoming anaemic?

Answer 21

In chronic diseases,
Cytokines such as
TNF alpha & interleukins
lead to decrease in erythropoietin production & also prevent normal flow of iron from duodenum to RBC

Question 22

Laboratory clues of anaemia of chronic disease

Answer 22

C - reactive protein HIGH  
Erythrocyte sedimentation rate HIGH 
Ferritin HIGH
Transferrin LOW 
Acute phase proteins INCREASE

Question 23

C reactive protein

Answer 23

Type of APP (acute phase protein)
Inflammation marker
Originates in liver
Follows interleukin 6 secretion

Question 24

Acute phase protein

Answer 24

[APP] change in response to inflammation.
Increase/decrease is acute phase reaction
Characteristically involves fever

Question 25

TNF

Answer 25

Tissue necrosis factor released in response to inflammation