Leukaemia Flashcards
The clinical features, laboratory diagnoses and treatment options for leukaemias
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The classification of the four types of acute and chronic leukaemias.
- Acute Lymphoblastic Leukaemia (ALL)
- Acute Myeloid Leukaemia (AML)
- Chronic Myeloid Leukaemia (CML)
- Chronic Lymphocytic Leukaemia (CLL)
What cells is blood made up of?
RBCs
WBCs
Platelets
Describe the basics of normal haematopoietic development.
stem cell
- -> committed progenitors
- -> mature (differentiated) cells
What are the two committed progenitor cell types?
Myeloid vs lymphoid
What do lymphoid progenitor cells become?
Naive B lymphocytes (–> plasma cells)
T lymphocytes
What do myeloid progenitor cells become?
Neutrophils Eosinophils Basophils Monocyte Platelets Red cells
What do myeloid progenitor cells become?
Neutrophils Eosinophils Basophils Monocyte Platelets Red cells
How haematological malignancies occur - what lineages do the following malignancies occur from?
ALL
AML
CLL
ALL - lymphoid progenitor cells
AML - myeloid progenitor
CLL - naive B lymphocytes
From what lineages do the following occur?
Lymphomas
Myeloma
Myeloproliferative disorders
T lymphocyte
Plasma cells
Neutrophils
From what lineages do the following occur?
Lymphomas
Myeloma
Myeloproliferative disorders
T lymphocyte
Plasma cells
Neutrophils, eosinophils, basophils, monocyte, platelets, red cells
Where do all the blood cells come from?
Bone marrow
What laboratory tools are there for diagnosing haematological malignancies?
Morphology – Blood film, Bone marrow biopsy
Immunophenotype – Flow cytometry
Genetic and molecular features – Chromosome abnormalities (G-banding and FISH), Gene point mutations, insertions/deletions (PCR-based)
Immunophenotyping - why is it useful?
Eg: blast and lymphocyte can look morphologically
similar even to trained eyes BUT immunologically diverse (different surface antigens).
It can help distinguish:
• Cancerous from normal tissue
• Different types of haematological malignancies
What is G banding used for?
How does it work?
Used to detect chromosomal abnormalities
Cells are cultured for a short time, then are stopped at metaphase and coloured by Giemsa
What is monosomy 7 a feature of?
AML
What is translocation 15:17 a feature of?
APML
What is FISH?
Technique using fluorescent probes to detect a
specific DNA sequences
What is FISH used for?
Does not need to be used with cells in metaphase
Can identify chromosomal translocations or gains or
losses of regions in the genome
What is a mutation?
Change in the DNA sequence
When can a mutation contribute to disease/cancer?
If the change affects the protein sequence and function of the translated protein
A 23 year old teacher visits her GP complaining of tiredness and gum bleeding.
On examination she is pale, has swollen gums and lots of bruising and petechia.
Blood tests showed:
• Hb: 5g/dL (low)
• WCC 150 (high)
• Plt 6 (low)
Given intensive chemotherapy but died due to overwhelming neutropenic sepsis.
What is the diagnosis?
AML
Acute leukaemias: AML and ALL
What are these characterised by?
Accumulation of large numbers of undifferentiated cells called ‘BLASTS ‘ in bone marrow, due to a block in differentiation. These blasts rapidly overwhelm normal blood cells and then spill into the peripheral blood.
How is AML and ALL diagnosed?
Diagnoses requires > 20% blasts in bone marrow or blood
Signs and symptoms of AML and ALL.
Low Hb - anaemia, tiredness, shortness of breath
WCC - infections if low or leucostasis (high white cell count making the blood viscous causing problems with blood flow in vessels leading to stroke/confusion/SOB) if high.
Low platelets - bleeding and bruising
Explain the signs and symptoms of AML/ALL.
They are signs and symptoms of bone marrow failure
How is AML/ALL treated?
Require intensive, high dose, myelosuppressive chemotherapy.
Prognosis of AML/ALL.
Aggressive/fast growing/fatal if untreated.
What age group is AML increasingly frequent in?
Older people (most common in 80-84 year olds)
Define Acute Myeloid Leukaemia.
Malignant transformation of a myeloid precursor cell usually at a very early stage of myeloid development.