Haematology (Week 4) Flashcards
Name three sites where haemopoietic stem cells occur
Bone marrow, umbilical cord blood and peripheral blood (after growth factor treatment)
What does asymmetrical stem cell division achieve?
One stem cell and one differentiated cell is produced which maintains stem cell numbers
Which feature of bone marrow stroma allows it to hold developing blood cells in place?
Stroma displays cell adhesion molecules which bind to developing cells to anchor them
During a bone marrow biopsy, which site is the sample taken from?
From the back of the iliac crest under local anaesthetic
Name the autoimmune anaemia condition which is of autosomal recessive inheritance?
Fanconi anaemia
What are autologous stem cell transplants?
These use the patients own blood after growth factor therapy which allows stem cells to leave bone marrow and be harvested
What is a syngeneic transplant?
A transplant between identical twins
Under what conditions does Met haemoglobin form?
This occurs rarely when the haem portion of haemoglobin becomes oxidised
Which molecule is iron bound to in the blood?
Transferrin (30% saturation)
What are the two storage forms of iron in macrophages of the RES after red blood cell breakdown?
Haemosiderin and ferritin
Roughly how many mg of iron does the RES store?
500mg
In what circumstances may serum ferritin be normal despite anaemia being present?
In inflammatory conditions (e.g. rheumatoid arthritis) because ferritin is an acute phase protein
What is the role of hepcidin and where is it produced?
Hepcidin reduces iron levels in the plasma by interactions with the membrane transporter ferroportin and is produced in the liver
In situations of raised ESR (indicating inflammation), what feature can red blood cells exhibit?
Rouleaux (stack of coins)
What type of anaemia can lead to vitamin B12 deficiency and how?
Pernicious anaemia
An AI condition affecting gastric parietal cells, meaning intrinsic factor is not produced so vitamin B12 cannot be bound and absorbed in the terminal ileum
What is meant by ‘thalassaemia’?
The absence of normal global chains due to absent genes
In cases of alpha thalassaemia, how many globin genes would need to be missing for a patient to suffer from HbH disease?
Three
What is hydrops foetalis?
The absence of all four alpha globin chains, meaning foetal haemoglobin cannot be produced. This condition is incompatible with life.
What adjunct therapy is needed in beta thalassaemia to prevent iron overload?
Iron chelation therapy with blood transfusions
In haemolytic anaemias, the bone marrow cannot continue to compensate for cells that live for less than how many days?
20
Which immunoglobulin molecule is involved in cold autoimmune haemolytic anaemia (AIHA)?
IgM
Which immunoglobulin molecule is involved in drug induced warm autoimmune haemolytic anaemia (AIHA)?
IgG
What is the difference in what the direct and indirect Coombs test looks for?
Direct: antibodies on RBC surface
Indirect: antibodies in plasma
In haemolytic disease of the new born, what is the rhesus status of the mother and foetus?
Mother: rhesus negative
Foetus: rhesus positive
What are the four classical types of Hodgkin’s lymphoma?
- Nodular sclerosing
- Mixed cellularity
- Lymphocytes rich
- Lymphocyte depleted
Name three B symptoms that a lymphoma patient may present with
Night sweats
Unexplained fever
Weight loss
What defines stage II lymphoma?
More than one affected lymph node group on the same side of the diaphragm
Name 2 types of aggressive B-cell lymphoma
Diffuse large B-cell lymphoma and Burkitt’s lymphoma
What the the mechanism of action of the cancer drug Rituximab?
A monoclonal antibody targeting CD20 antigens expressed on B-lymphocytes
Name the 5 drugs involved in RCHOP chemotherapy
Rituximab Cyclophosphamide Adriamycin Vincristine Prednisolone
Name the four drugs involved in ABVD chemotherapy
Adriamycin
Bleomycin
Vinblastine
Darcarbazine
What is the classical triad of myeloma?
- Lytic bone lesions
- Increased plasma cells in bone marrow
- Clonal immunoglobulins/paraproteins
What is the name given to asymptomatic myeloma in which a ‘watch and wait’ method is used?
Smouldering myeloma
What does MGUS stand for?
Monoclonal gammopathy of undetermined significance
Myelodysplastic syndromes are characterised by what kind of haemopoiesis?
Ineffective
What type of diseases are characterised by haemopoiesis which is too effective?
Myeloproliferative diseases
What happens to blood counts in acute leukaemia?
Blood counts fall due to compromise of normal marrow
In acute lymphoblastic leukaemia (ALL), which chromosomal abnormality occurs?
9:22 translocation (Philadelphia chromosome)
Describe the mechanism of action of Imatinib
Blocks Brc-Abl phosphorylation meaning the abnormal protein cannot be formed
What are the vitamin K dependent clotting factors?
2, 7, 9 and 10
