Introduction to Haematology Flashcards
What is haematology?
Branch of medical science concerned with diseases of the blood and blood forming tissues
Name two anticoagulants
Warfrin
DOACs
Why do we no longer use warfrin
It was easy to overdose on
Need to monitor its levels
Had bad side effects
Why do we now use DOACs
No monitoring needed
Give an example of a targeted therapy
Tyrosine kinase inhibitors -> Gleevek for chronic myeloid leukemia
How does Gleevek work?
Tyrosine Kinase Inhibitor
CML caused by hyper reactive tyrosine kinase
98% of people with chronic myeloid leukemia have this mutation
This allows people to live with this condition
What is bone marrow and what is it’s job
Soft tissue located inside hollow bones responsible for the production and maturation of blood cells
What is peripheral blood
The blood that is contained within the circulatory system
What is haemostasis
The interplay of cellular and molecular processes that maintain blood fluidity and also generate blood clots at sites of injury. regulate clot formation and degrade clots
List the causes of anaemia
(5)
Iron deficiency
Vitamin B12 or folate deficiency
Hereditary conditions
Acute or chronic blood loss
Other diseases e.g. malignancy
When might levels of wbcs be altered?
Infection
Leukaemia
What may cause increased levels of mature wbcs
Bacterial, viral and fungal infections
What may cause increased levels of immature wbcs
Leukaemia
What may cause decreased levels of immature wbcs
(3)
Medications
Cytotoxic chemotherapy
Aplastic anaemia
What two events may affect haemostasis
Haemorrhage
Thrombosis
Why might we need to monitor blood homeostasis
Diagnosing bleeding and thrombotic disorders
Monitoring anticoagulant therapy
List some examples of haematological disorders
(4)
Glandular fever
Leukaemia
Haemophilia
Iron deficiency anaemia
Why might we carry out blood films or FBCs
Detection of anaemia, morphology, infection or inflammation
What test do we use to measure haemostasis
Coagulation tests
Give an example of a haematological neoplasm
Leukaemia
What two vacutainers do we see most in the haematology lab
Blue
Purple
What may a purple vacutainer be used for?
Whole blood
What may a blood vacutainer be used for
It’s for coagulation tests -> contains sodium citrate anti-coagulant
What might go wrong when using blue vacutainers
The clinician must fill up the vacutainer to the line -> if they don’t there will be way too much anti-coagulant
What does the purple vacutainer contain
EDTA
Ethylene-diamine-tetra-acetic acid
For what tests do we use blood in a purple vacutainer
FBC
Blood film
Malaria parasites
Reticulocytes
Red cell folate
Monospot
Why is sodium citrate and not EDTA used in the blue vacutainers
Sodium citrate is a reversible anticoagulant
For what test may we use blood from a blue vacucontainer
(3)
Coagulation screen including platelet function
Factor assays
Thrombin time (TT) and fibrinogen assay
How do we obtain a bone marrow sample
Bone marrow aspiration
Bone marrow trephine
What is bone marrow aspiration
Push a heavy duty needle into a particular bone e.g. pelvis
What is bone marrow trephine
Obtain a larger sample of bone that will include bone tissue as well as bone marrow/biopsy of tissue from the hip
List some tests used in the haematology lab
(8)
Blood film
Erythrocyte sedimentation rate (ESR)
Coagulation screening
Monospot
Malaria screening
Full Blood count
Genetic testing
Haemoglobin variant detection
Haematinic assays
What may be detected using a full blood count
(6)
Anaemia
Bacterial infection
Viral infection
Allergic reactions
Platelet associated bleeding disorders
Leukaemia or lymphoma
What can we monitor using a full blood count
Monitor treatment
Monitor bone marrow response to chemotherapy
List six investigative laboratory techniques
Spectrometry
Impedance
Flow cytometry
Light microscopy
Immunoassays
Genetic/molecular biology
What do we use a spectrometer to detect
used to obtain haemoglobin result
How do we detect haemoglobin used a spectrometer
Detergent destroys the rbc membrane to release haemoglobin
Add Drabkin’s solution
Haemoglobin converted to cyanmethaemoglobin
Use Beer Lambert Law to determine the concentration of Hb
What is Beer Lamberts Law
Density of colour is proportional to the Hb present in the sample
What is the principle of impedance
(3)
Relies on the ability of an ionic fluid to assist the passage of electricity from one electrode to another
This passage can be interrupted by particles
The higher the number of cells the greater the frequency of disturbances in the flow of electricity
We can use impedance to count what cell types
RBCs
WBCS
Platelets
What is the principle of flow cytometry
(4)
It relies on the disruption of a laser
The degree to which laser is interrupted (forward scatter) is proportional to size of cell
The degree to which light is scattered obliquely (side scattered light) is proportional to cell granularity
Frequency of interruption relates to cell number
Why might we use a flow cytometer
Differentiate and count wbcs
How do we use a flow cytometer to differentiate and count WBCs
Antibodies conjugated to a flurochrome to quantify cell subtypes
What diagnosis could be made using a flow cytometer
White cell malignancies
Red cell disorders
Platelet disorders
Why might we use a light microscope
(5)
Examination of blood cell morphology
Quality check in FBC
Manual differential counts
Identify parasites
Identify disease
When might we use immunoassays
Not commonly used -> usually only as follow up tests
Used to measure plasma concentrations of various proteins e.g. those involved in coagulation
Give three examples of immunoassays used
Enzyme-linked immunosorbent assays
Latex immunoassays
Immunophelometry
When would genetics be used in the haematology lab
Recently the role of certain genes have been noted in diseases
e.g. CML caused by BCR-ABL mutations
