Haemotology Lectures Flashcards
Where are DVTs generally found?
Between hip and knee
What type of DVTs cause significant PEs?
DVTs above the knee.
What are pulmonary embolisms
Embolus blocks a pulmonary artery, preventing blood oxygenation.
What are DOACs?
Direct oral anti-coagulants.
List 2 reasons why are DOACs better than warfarin.
1) shorter half life
2) no monitoring required
List 2 types of thrombus.
1) white thrombus
2) red thrombus
List 3 features of white thrombi.
1) platelet rich
2) occur in arterial circulation (high pressure)
3) cause MIs, strokes and PVDs
List 3 features of red thrombi.
1) fibrin rich
2) occur in venous circulation (low pressure)
3) cause DVTs and PEs
How does heparin work?
1) binds to antithrombin
2) increases antithrombin activity
3) deceases coagulation
List 3 advantages of low molecular weight heparin over unfractionated heparin.
1) smaller molecule
2) less dose variation
3) renally excreted
What is the normal haemoglobin range? (2)
1) male Hb 131 - 166 g/L
2) female Hb 110 - 147 g/L
What is the life span of an erythrocyte?
120 days.
List 4 ways erythrocytes can be removed.
1) spleen*
2) liver
3) bone marrow
4) blood loss
List the 3 types of anaemia.
1) microcytic
2) normocytic
3) macrocytic
Define mean corpuscular volume.
Average volume of red blood cells.
What is the normal MCV range? (2)
1) male MCV 81.8 - 96.3 fl
2) female MCV 80.0 - 98.1 fl
therefore roughly 80 - 100 fl
Define reticulocyte count.
Count of immature erythrocytes in the bone marrow.
Describe changes to the RCC. (2)
1) low RCC - RBC production issue
2) high RCC - RBC removal issue
List 4 side effects of ferrous sulphate.
1) nausea
2) abdominal discomfort
3) diarrhoea/constipation
4) black stools
List 5 conditions that cause secondary anaemia (anaemia of chronic disease).
1) tuberculosis
2) Crohn’s disease
3) rheumatoid arthritis
4) systemic lupus erythematosus
5) malignancy
List 3 sources of vitamin B12.
1) meat
2) fish
3) dairy
What dietary choice can lead to vitamin B12 deficiency?
Veganism.
Describe pernicious anaemia’s pathophysiology. (4)
1) autoimmune disorder
2) stomach parietal cells attacked
3) no intrinsic factor production
4) vitamin B12 malabsorption
List 4 sources of vitamin B9 (folate).
1) green vegetables
2) nuts
3) yeast
4) liver
What is folate essential for?
DNA synthesis.
List 5 things that can precipitate sickling of erythrocytes in sickle cell disease.
1) infection
2) dehydration
3) cold
4) acidosis
5) hypoxia
Describe the heterozygous sickle cell trait.
1) symptom free
2) protection against falciparum malaria
List the 4 main types of leukaemia.
1) acute lymphoblastic leukaemia (ALL)
2) chronic lymphocytic leukaemia (CLL)
3) acute myeloid leukaemia (AML)
4) chronic myeloid leukaemia (CML)
Describe leukaemia.
Presence of rapidly proliferating defective immature blast blood cells in the bone marrow.
What population is sickle cell disease generally seen in?
African (1/700).
What is the prognosis of sickle cell disease? (2)
1) males 42 years
2) females 48 years
What leukaemia is mainly present in childhood?
Acute lymphoblastic leukaemia (especially 2-4 years).
What leukaemia is mainly present in the elderly?
Chronic lymphocytic leukaemia.
Proliferation of what cells causes acute lymphoblastic leukaemia? (1)
1) lymphoblasts
Proliferation of what cells causes chronic lymphocytic leukaemia? (1)
1) B lymphocytes
Proliferation of what cells causes acute myeloid leukaemia? (2)
1) common myeloid progenitor
2) myeloblast
Proliferation of what cells causes chronic myeloid leukaemia? (3)
1) basophils
2) eosinophils
3) neutrophils
What is the most common leukaemia?
Chronic lymphocytic leukaemia.
List 2 differences between lymphocytic leukaemias and lymphomas.
1) lymphocytic leukaemias begin in bone marrow; lymphomas begin in lymphocytes
2) lymphocytic leukaemia cells are found in bone marrow/blood; lymphoma cells are found in lymph nodes/other tissue
What is the characteristic cell of classical Hodgkin’s lymphoma?
Reed-Sternberg cells, mirror image nuclei.
What is the characteristic cell of modular lymphocyte predominant Hodgkin’s lymphoma?
Popcorn cells, popcorn-like nuclei.
How many types of non-Hodgkin’s lymphoma are there?
> 30.
What does Epstein-Barr virus cause?
Infectious mononucleosis, glandular fever.
Describe the Ann Arbor classification of lymphomas. (6)
1) I - one lymph node group
2) II - multiple lymph node groups same side of the diaphragm
3) III - multiple lymph node groups either side of the diaphragm
4) IV - spread beyond lymph nodes (e.g. liver or bone marrow)
5) A - no B symptoms
6) B - B symptoms
List the 3 main B symptoms.
1) weight loss
2) fever
3) night sweats
Describe the cell origin of non-Hodgkin’s lymphoma. (2)
1) B lymphocytes - 80%
2) T lymphocytes - 20%
What is the most common non-Hodgkin’s lymphoma?
Diffuse large B-cell lymphoma.
What is a raised lactose dehydrogenase a sign of?
Increased cell turner.
Describe rituximab. (2)
1) monoclonal antibody
2) targets CD20 expressed on B lymphocyte cell surface.
What is the highest grade of non-Hodgkin’s lymphoma?
Burkitt’s lymphoma.
What immunoglobulins are produced in excess in myeloma? (3)
1) IgG (55%)
2) IgA (20%)
3) rarely IgM or IgD
How many types of immunoglobulin are produced in excess in myeloma?
1.
List the 3 main complications of myeloma.
1) bone disease
2) hypercalcaemia
3) renal failure
What is the mnemonic for myeloma presentation?
OLD CRAB
1) old
2) calcium (hypercalacaemia)
3) renal failure
4) anaemia
5) bone disease
How does myeloma cause bone lytic lesions? (2)
1) activate osteoclasts —> increasing bone breakdown
2) inhibit osteoblasts —> decreasing bone synthesis
How does myeloma cause renal failure? (4)
1) raised immunoglobulins (proteins)
2) proteins precipitate and deposit in kidneys
3) kidney injury
4) renal failure
List the 3 types of haemoglobin found in adults.
1) HbA (2α + 2β) - 97%
2) HbA2 (2α + 2δ) - 2%
3) HbF (2α + 2γ) - 1%
What is a HBB β+ allele?
A partially functioning beta globin.
What is a HBB β0 allele?
A non functioning beta globin.
List 5 regions where beta thalassaemia is common.
1) Mediterranean
2) North Africa
3) Middle East
4) Indian Subcontinent
5) South East Asia
What is beta thalassaemia minor often confused with?
Iron-deficient anaemia.
When does beta thalassaemia often present?
Within 1st year of life.
List 2 causes of microcytic anaemia.
1) iron deficiency*
2) thalassaemia
List 6 causes of normocytic anaemia.
1) chronic disease
2) combined haematinic (iron + B9)
3) acute blood loss
4) renal failure
5) pregnancy
6) sickle cell disease
List 6 causes of macrocytic anaemia.
1) B9 (folate) deficiency
2) B12 deficiency (esp. pernicious anaemia
3) liver disease (alcohol)
4) chemotherapy
5) hypothyroidism
6) bone marrow failure
What haemoglobin is found in four gene deletion alpha thalassaemia?
HbBarts (4 γ globin)
What haemoglobin is found in 3 gene deletion alpha thalassaemia?
HbH (4 β globin)
Define haemocrit.
Percentage volume of blood that is erythrocytes.
List 2 alternative names for haemocrit.
1) red cell count
2) packed cell volume
What is polycythaemia?
Increased red blood cell mass.
What can cause polycythaemia? (2)
1) increased RBC mass
Or
2) decreased plasma volume
What is the treatment aim for polycythaemia vera?
There’s no cure, so aim to maintain a low blood count with haemocrit > 0.45 to reduce risk of thrombosis.
What is the lifespan of a platelet?
7-10 days.
What hormone regulates platelet production?
Thrombopoietin.
Where us thrombopoietin predominantly synthesised?
Liver.
How many platelets are produced per megakarkyocyte?
Approximately 4000.
Where platelets broken down?
Spleen.
List 3 general causes of platelet dysfunction.
1) decreased platelet production (thrombocytopenia)
2) decreased platelet function
3) increased platelet destruction (thrombocytopenia)
List 4 clinical features of platelet dysfunction.
1) mucosal bleeding (e.g. epistaxis, gum bleeding, menorrhagia)
2) easy bruising
3) petechia, purpura, ecchymosis
4) haematomas
Define thrombocytopenia.
Decreased platelets in blood.
List 3 general causes of decreased platelet production.
1) decreased bone marrow platelet production
2) congenital thrombocytopenia (absent/malfunctioning megakaryocytes)
3) bone marrow infiltration (e.g. leukaemia)
List 6 causes of decreased bone marrow platelet production.
1) low B9/B12
2) reduced thrombopoietin (e.g. liver disease)
3) chemotherapy (e.g. methotrexate)
4) infections (e.g. HIV or TB)
5) toxins (e.g. alcohol)
6) autoimmune (e.g. aplastic anaemia)
List 4 causes of increased platelet destruction.
1) autoimmune (e.g. immune thrombocytopenia purpura)
2) hypersplenism (e.g. portal hypertension, splenomegaly)
3) drug related immune destruction (e.g. heparin induced)
4) excessive platelet use (disseminated intravascular coagulopathy, thrombotic, thrombocytopenia purpura)
What type of diagnosis is immune thrombocytopenia purpura?
Diagnosis of exclusion.
List 4 things that should be absent to diagnose immune thrombocytopenic purpura.
1) systemic symptoms
2) medications that causes thrombocytopenia
3) hepatomegaly/splenomegaly
4) lymphadenopathy
What does a positive direct Coombs test indicate?
Haemolytic anaemia.
How long does it take for platelets to sharply fall in heparin induced thrombocytopenia?
5-10 days.
List 2 reasons why ferritin may be low.
1) malignancy
2) infection
