Haem: Acute Leukaemia Pt.2 Flashcards
Outline the tests that may be used to diagnose AML.
- Blood film (DIAGNOSTIC) - can see circulating blast cells
- Bone marrow aspirate
- Cytogenetic studies (done in EVERY patient)
- Molecular studies and FISH
What is the significance of cytogenetic and molecular analysis in AML
Prognostic value and guides treatment
What is aleukaemia leukaemia?
When there are no leukaemic cells in the peripheral blood but the bone marrow has been replaced
Outline the treatment for AML.
Chemotherapy
BM transplant if treatment resistant
Supportive (important for patient to survive chemo)
- Red cells
- Platelets
- FFC/cryoprecipitate in DIC
- Antibiotics
- Allopurinol (prevent gout)
- Fluid and electrolyte balance
Describe the chemotherapy regime in AML
- Combination chemotherapy is ALWAYS used
- Usually given as 4-5 courses: 2x remission induction + 2/3x consolidation
- Treatment usually lasts around 6 months
List some determinants of prognosis in AML.
- Patient characteristics
- Morphology
- Immunophenotyping
- Cytogenetics
- Genetics
- Response to treatment
How is AML differentiated from ALL
Immunophenotyping: identifies cell surface and cytoplasmic antigens
- Flow cytometry
- Immunocytochemistry
- Immunohistochemistry
Describe the epidemiology of ALL
Peak incidence in childhood (most common childhood malignancy)
Outline the clinical features of ALL.
Systemic symptoms
Bone marrow failure
- Anaemia
- Neutropenia
- Thrombocytopenia
Local infiltration
- Lymphadenopathy
- Splenomegaly
- Hepatomegaly
- Bone marrow
- Testes, CNS
What is seen on peripheral blood smear and BM biopsy in ALL?
Lymphoblasts
What is a key difference in the origin of B-lineage and T-lineage ALL?
- B-lineage starts in the bone marrow
- T-lineage can start in the thymus (which may be enlarged)
List some possible leukaemogenic mechanisms in ALL.
Protooncogene dysregulation due to chromosomal abnormalities
- Fusion genes
- Wrong gene promotor
- Dysregulation due to proximity to TCR or Ig heavy chain loci
- Hyperdiploidy - mechanism unknown
List some investigations used in the diagnosis of ALL.
- FBC and blood film
- Bone marrow aspirate
- Immunophenotyping
- Cytogenetic/molecular analysis
Why is immunophenotyping important in ALL
- Differentiate between AML and ALL (treated differently)
- Differentiate between B cell and T cell lineage (treated differently)
Why is cytogenetic/molecular analysis important in ALL
Prognosis and treatment guidance:
- Philidephia chr positive ALL requires imatinib
- Treatment must be tailored to prognosis
