Haem: Haematology of Systemic Disease Pt.2 Flashcards
What is the main difference seen in the blood film of patients with acute and chronic leukaemia?
- Chronic - mature white cells are raised
- Acute - immature blast cells are raised
List some causes of neutrophilia.
- Corticosteroids (due to demargination)
- Underlying neoplasia
- Tissue inflammation (e.g. colitis, pancreatitis)
- Myeloproliferative/leukaemia disorder
- Infection
List some infections that characteristically do not cause neutrophilia.
- Brucella
- Typhoid
- Many viral diseases
List some key features of a reactive neutrophilia on a blood film.
- Band cells (presence of immature neutrophils (band cells) show that the bone marrow has been signalled to release more WBCs)
- Toxic granulation
- Clinical signs of infection/inflammation
What are some key blood film and clinical features suggestive of a myeloproliferative disorder?
- Neutrophilia
- Basophilia
- Immature myelocytes
- Splenomegaly
NOTE: you may see raised Hb and raised platelets in CML if it affects those lineages
What are some key blood film features suggestive of AML?
- Neutrophilia
- Myeloblasts
List some causes of monocytosis.
- Bacteria: TB, Brucella, typhoid
- Viral: CMV, VZV
- Sarcoidosis
- Chronic myelomonocytic leukaemia
List some causes of reactive eosinophilia.
- Parasitic infection
- Allergy (e.g. asthma, rheumatoid arthritis)
- Underlying neoplasms (e.g. Hodgkin’s lymphoma, T cell lymphoma, NHL)
- Drug reaction (e.g. erythema multiforme)
Which gene mutation causes chronic eosinophilic leukaemia?
FIP1L1-PDGFRa fusion gene
Which type of virus typically causes basophilia?
Pox viruses
What investigations are typically used when investigating lymphocytosis?
- Clinical examination
- FBC
- Light microscopy
- Flow cytometry (identify lineage and stage of differentiation)
- Molecular genetics (TCR or Ig gene)
List some causes of reactive lymphocytosis.
- Infection (EBV, CMV, toxoplasmosis, rubella, HSV)
- Autoimmune diseases (NOTE: these are more likely to cause lymphopaenia)
- Sarcoidosis
How would the lymphocytes seen on a blood film due to a viral infection be different from leukaemia/lymphoma?
- Viral infection: reactive or atypical lymphocytes (EBV)
- CLL or NHL: small lymphocytes and smear cells
Outline how flow cytometry is used to identify cell types.
- Fluorescently labelled monoclonal antibodies targeted at different antigens are washed over the cells
- Cells are passed through the flow cytometer and the fluorescence is recorded
- Dependent on the antigens present on the cells, you can identify the stage of maturation
What is light chain restriction?
- An individual B cell will either express kappa or lambda light chains (not both)
- In response to an infection, you will get polyclonal B cell response so there will be a roughly even mixture of kappa and lambda light chains
- In lymphoproliferative disorders, monoclonal proliferation of a B cell expressing only one type of light chain (e.g. kappa) will mean that the proportion of kappa relative to lambda will increase (e.g. showing an overwhelming majority of kappa)
