blood cell abnormalities Flashcards
(25 cards)
Why does leukaemia occur?
Mutations in oncogenes or tumour suppressor genes lead to cell growth/survival advantage.
clone replaces normal cells
abnormal behaviour of the rebellious leaukaemic clone:
Growth independent of growth factors
Continued proliferation without maturation
Failure to undergo apoptosis
4 leukaemia types
Acute lymphoblastic leukaemia (ALL)
(Infancy)
Acute myeloid leukaemia (AML)
(Late middle/old age)
Chronic myeloid leukaemia (CML)
Chronic lymphoid leukaemia (CLL)
Acute leukaemia:
Where mutation occurs/ nature of mutation
Result of mutation
Acute leukaemia - mutations in genes encoding transcription factor.
Result:
abnormal maturation + continued proliferation = blast cell accumulation (lymphoblasts/myeloblasts)
Chronic myeloid leukaemia:
Nature of mutation:
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
Why CHRONIC myeloid leukaemia has less impairment of normal physiological processes than acute
Maturation still occurs. Mature end cells still able to function.
Directs effects of proliferation of leukaemic cells
Bone pain
Hepatomegaly
Splenomegaly
Lymphadenopathy (swollen lymph nodes
InDirects effects of leukaemic cell proliferation
Fatigue, lethargy, pallor (anaemia)
Fever & infection (neutropenia)
Bruising & petechiae (thrombocytopenia)
Bone pain (bone marrow expansion)
Abdominal enlargement (hepatosplenomegaly)
Lumps & swelling (lymphadenopathy)
Essential investigations
Full blood count
Blood film
Flow cytometry
Mechanisms that result in anaemia
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
Instruments used to identify Microcystic anaemia
Microscope- to observe blood film: RBC - small & hypochromic
Automated blood cell counter - measures mean cell volume
Common causes of microcytosis
Reduced synthesis of haemoglobin:
Iron deficiency anaemia
Anaemia of chronic disease
=> reduced synthesis of haem
Thalassaemia
=> reduced synthesis of globin
Causes of iron deficiency
Increased blood loss
Insufficient intake
Increases requirements
Causes of iron deficiency:
Examples of increased blood loss
Menstrual (menorrhagia)
Hookworms
Gastrointestinal bleeding (silent/asymptomatic)
Causes of iron deficiency:
Examples of insufficient intake
Dietary- vegetarianism
Malabsorption
- coeliac disease (gluten induced enteropathy)
-H.pylori gastritis
Causes of iron deficiency:
Increased requirements
Pregnancy
Infancy
3 stages of iron depletion
Hint: DDA
Depletion: Storage iron reduced or absent
Deficiency: Low serum iron & transferrin saturation
Anaemia: Low haemoglobin & haematocrit
Iron deficiency anaemia; clinical features
- Pallor, fatigue, breathlessness
- Impaired intellectual development in children
- koilonchia (nails)
- angular Cheilitis (around mouth)
Anaemia of chronic disease: what TYPE of patients are at risk?
Patients who are already unwell, usually with an inflammatory aspect to their underlying disease
Anaemia of chronic disease:
Causes
Rheumatoid arthritis Autoimmune disease Malignancy Kidney disease Infections such as TB or HIV
Why does chronic disease lead to people becoming anaemic?
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
Laboratory clues of anaemia of chronic disease
C - reactive protein HIGH Erythrocyte sedimentation rate HIGH Ferritin HIGH Transferrin LOW Acute phase proteins INCREASE
C reactive protein
Type of APP (acute phase protein)
Inflammation marker
Originates in liver
Follows interleukin 6 secretion
Acute phase protein
[APP] change in response to inflammation.
Increase/decrease is acute phase reaction
Characteristically involves fever
