Haematology Flashcards
Aplastic crises
- caused by?
- lab findings?
- caused by infection with parvovirus
- sudden fall in haemoglobin
- bone marrow suppression causes a reduced reticulocyte count
Sequestration crises:
- seen in?
- clinical findings?
- lab findings?
- seen in sickle cell anemia
- sickling within organs such as the spleen or lungs causes pooling of blood with worsening of the anaemia
- associated with an increased reticulocyte count
- known sickle cell anaemia presents with abdominal pain, splenomegaly and anemia
CML is associated with
Philadelphia chromosome - t(9:22)
Philadelphia chromosome is associated with
CML
The Philadelphia translocation is seen in around 95% of patients with chronic myeloid leukaemia. Around 25% of adult acute lymphoblastic leukaemia cases also have this translocation.
It is due to a translocation between the long arm of chromosome 9 and 22 - t(9:22)(q34; q11). This results in part of the ABL proto-oncogene from chromosome 9 being fused with the BCR gene from chromosome 22. The resulting BCR-ABL gene codes for a fusion protein that has tyrosine kinase activity in excess of normal.
What is the chromosomal abnormality in Philadelphia chromosome?
- t(9:22)
t(9;22) - Philadelphia chromosome is a poor prognostic indicator in
ALL
What is a poor prognostic indicator for ALL?
Philadelphia chromosome
Hereditary Spherocytosis is diagnosed by
- the osmotic fragility test previously
- the British Journal of Haematology (BJH) guidelines state that ‘patients with a family history of HS, typical clinical features and laboratory investigations (spherocytes, raised mean corpuscular haemoglobin concentration [MCHC], increase in reticulocytes) do not require any additional tests
- if the diagnosis is equivocal > EMA binding (Eosin-5€²-maleimide (EMA) binding test) test and the cryohaemolysis test
- for atypical presentations electrophoresis analysis of erythrocyte membranes is the method of choice
Lab Findings of Hereditary Spherocytosis
- spherocytes
- raised mean corpuscular haemoglobin concentration [MCHC],
- increase in reticulocyte
Hereditary Spherocytosis vs G6PD
- Hereditary Spherocytosis is inherited in a ———– fashion
- seen mostly in which ethnicity?
- Autosomal Dominant
(Male + female) - Northern European descent
- G6PD is inherited in a ——— manner.
- seen mostly in which ethnicity?
- X Liked recessive(Male only)
- African+Mediterranean descent
Key Blood film in G6PD
Heinz Body
Key Blood film finding in Hereditary spherocytosis
Spherocytes (round, lack of central pallor)
Follicular lymphoma is characterised by ———— translocation
t(14:18) translocation
Follicular lymphoma is driven by a translocation involving Ig heavy chain on chromosome 14 and BCL2 on chromosome 18.
Lymphoma classification
Lymphoma is the malignant proliferation of lymphocytes which accumulate in lymph nodes or other organs. Lymphoma may be classified as:
- Hodgkin’s lymphoma (a specific type of lymphoma characterized by the presence of Reed-Sternberg cells)
- non-Hodgkin’s lymphoma (every other type of lymphoma that is not Hodgkin’s lymphoma). may affect either B or T-cells and can be further classified as high grade or low grade.
- Non-Hodgkin’s lymphoma is much more common than Hodgkin’s lymphoma
- Low-grade non-Hodgkin’s lymphoma has a better prognosis
- High-grade non-Hodgkin’s lymphoma has a worse prognosis but a higher cure rate
Investigation of choice for Lymphoma
Excisional node biopsy is the diagnostic investigation of choice
-certain subtypes will have a classical appearance on biopsy such as Burkitt’s lymphoma having a ‘starry sky’ appearance
- CT chest, abdomen and pelvis (to assess staging)
- HIV test (often performed as this is a risk factor for non-Hodgkin’s lymphoma)
- FBC and blood film (patient may have a normocytic anaemia and can help rule out other haematological malignancy such as leukaemia)
- Prognostic indicator ESR, LDH (LDH is marker of cell turnover)
- Other investigations can be ordered as the clinical picture indicates (LFT’s if liver metastasis suspected, PET CT or bone marrow biopsy to look for bone involvement, LP if neurological symptoms)
Clinical Presentation of Lymphoma
- Painless lymphadenopathy (non-tender, rubbery, asymmetrical)
- Constitutional/B symptoms (fever, weight loss, night sweats, lethargy)
- Extranodal Disease - gastric (dyspepsia, dysphagia, weight loss, abdominal pain), bone marrow (pancytopenia, bone pain), lungs, skin, central nervous system (nerve palsies)Rre
Clinical difffernetiation between Hodgkin vs Non-Hodgkin Lymphoma
- Biopsy mainly
- Lymphadenopathy in Hodgkin’s lymphoma can experience alcohol-induced pain in the node
- ‘B’ symptoms typically occur earlier in Hodgkin’s lymphoma and later in non-Hodgkin’s lymphoma
- Extra-nodal disease is much more common in non-Hodgkin’s lymphoma than in Hodgkin’s lymphoma
Risk factors for Non-Hodgkin Lymphoma
A- Autoimmune disease (SLE, Sjogren’s, coeliac disease)
B- History of viral infection (specifically Epstein-Barr virus)
C- Caucasians, chemical agents (pesticides, solvents), History of chemotherapy or radiotherapy
D- ImmunoDEFICIENCY (transplant, HIV, diabetes mellitus)
E- Elderly
F- Family history
which test used to investigate to cause of anaphylaxis?
Radioallergosorbent test (RAST) - is used for Anaphylaxis
Burkitt’s lymphoma has a _______ appearance in LN Biopsy
‘starry sky’ appearance
Prognostic indicator of Lymphoma?
ESR
LDH
Which type of non-Hodgkin’s lymphoma has a better prognosis?
Low-grade non-Hodgkin’s lymphoma has a better prognosis
How to assess allergies?
Skin prick is used for ——
Skin prick is contraindicated in ———
Skin patch is used for ——-
Radioallergosorbent test (RAST) - is used for ———
Skin prick is used for food allergies and pollen.
Skin Prick is Contraindicated in anaphylaxis and patients on oral antihistamine
Skin patch is used for contact dermatitis
Radioallergosorbent test (RAST) - is used for Anaphylaxis ( Useful for food allergies, inhaled allergens (e.g. Pollen) and wasp/bee venom). Determines the amount of IgE that reacts specifically with suspected or known allergens, for example IgE to egg protein. Results are given in grades from 0 (negative) to 6 (strongly positive)
What is Philadelphia chromosome?
It is due to a translocation between the long arm of chromosome —– and —– ?
It is due to a translocation between the long arm of chromosome 9 and 22 - t(9:22)(q34; q11). This results in part of the ABL proto-oncogene from chromosome 9 being fused with the BCR gene from chromosome 22. The resulting BCR-ABL gene codes for a fusion protein that has tyrosine kinase activity in excess of normal.
First line Rx for CML
Imatinib is now considered first-line treatment
inhibitor of the tyrosine kinase associated with the BCR-ABL defect
Management of CML
Hint:
IHIA
IHIA
I- Imatinib is now considered first-line treatment
inhibitor of the tyrosine kinase associated with the BCR-ABL defect
very high response rate in chronic phase CML
H- Hydroxyurea
I - Interferon-alpha
A - Allogenic bone marrow transplant
Von Willebrand’s disease types and inheritence
- most common inherited bleeding disorder.
- characteristically behaves like a platelet disorder i.e. epistaxis and menorrhagia are common whilst haemoarthroses and muscle haematomas are rare
type 1: partial reduction in vWF (80% of patients)
type 2*: abnormal form of vWF
type 3**: total lack of vWF (autosomal recessive)
Majority is Autosomal Dominant
Type 3 is Autosomal recessive.
What is VWF
Role of von Willebrand factor:
- large glycoprotein which forms massive multimers up to 1,000,000 Da in size
- promotes platelet adhesion to damaged endothelium
- carrier molecule for factor VIII
Rx of VW Disease
- Tranexamic acid for mild bleeding
- Desmopressin (DDAVP): a synthetic analogue of the antidiuretic hormone vasopressin. It stimulates the release of von Willebrand factor (vWF) from Weibel-Palade bodies within endothelial cells, thereby elevating vWF levels. VWF then facilitates haemostasis by enhancing platelet adhesion to damaged endothelium and stabilising factor VIII. Desmopressin should be the initial treatment choice for both therapeutic and prophylactic interventions in minor spontaneous, traumatic, or surgical bleeding episodes associated with von Willebrand’s disease. Nevertheless, caution is needed when using desmopressin during childbirth due to potential risks such as fluid retention and hyponatraemia. Factor VIII concentrates, which contain both factor VIII and vWF, might also be utilised in severe cases where there is a significant deficiency or when desmopressin is not effective.
- factor VIII concentrate
Lab findings of VW Disease
Prolonged bleeding time
APTT may be prolonged
Factor VIII levels may be moderately reduced defective platelet aggregation with ristocetin