Haematology Flashcards
Standard dose of iron supplementation?
Ferrous Fumarate 210mg tds for 3 months
Take with food (reduce SE)
Standard dose for folate deficiency?
Folic acid 5mg od for 4 months
Standard dose for B12 deficiency?
Loading doses- 3 injections weekly for 2 weeks, them 3 monthly (usually for life)
What is microangiopathic haemolytic anaemia associated with?
Prosthetic heart valves (malfunctioning)
Smoking can cause an increase in?
Hb, RBC, WCC
What does chronic marrow hyperplasia cause?
Short stature
Increase energy demand in marrow= decreased energy for growth
What is the test for autoimmune haemolytic anaemia?
Direct Coomb’s test
What is warm autoimmune haemolytic anaemia?
IgG mediated
What is cold autoimmune haemolytic anaemia?
IgM mediated
Lifespan of a neutrophil?
7-8 hours in blood
Few days in tissue
What are B symptoms?
Weight loss, fever, night sweats
What does high PV indicate?
Increased protein in blood
- immunoglobulins (very high increase- usually malignant),
- acute phase reaction proteins (mild increase) etc.
How can high PV be further investigated?
Electrophoresis
What is rouleaux?
Stacks or aggregations of RBC
Occurs when plasma protein concentration is high
What is the target INR?
2.5 (2-3)
What is a leucoerythroblastic blood film?
Immature RBC and immature white cells in the blood stream
What can interact with warfarin and increase efficacy? (high INR)
Antibiotics
In haemolysis, what happens to haptoglobin and LDH levels in blood?
Haptoglobin decreases- binder for free Hb in RBC
LDH increases - releases from RBC
What is MAHA?
Increased activation of coagulation forms fibrin mesh- RBC are physically damaged by these networks.
Small vessel damage to organs
What 3 things does TTP (Thrombotic Thrombocytopenic Purpura) cause?
Low platelets
Low RBC
Kidney Failure
(similar to HUS)
What are CRAB criteria for myeloma?
Calcium elevation
Renal failure
Anaemia
Bone disease
What is Rituximab?
Monoclonal antibody than binds CD20 on lymphoma/leukaemia cells and induces lysis and apoptosis
What is Imatinib?
Tyrosine Kinase Inhibition
For cancers with Philadelphia chromosome (CML, ALL)
What can gram negative bacteria cause in neutropenic patients?
Fulminant life-threatening sepsis
What should everyone with a diagnosis of Non-Hodgkin’s Lymphoma be tested for?
HIV
Important cause of generalised lymphadenopathy +/- lymphopenia/thrombocytopenia?
HIV
What is used to monitor intrinsic pathway?
APTT
play table tennis INside
What is used to monitor extrinsic pathway?
PT
PT= less extra letters
Which pathway does heparin act on?
Intrinsic pathway
INtrinsic= heparIN
Which pathways does warfarin act on?
eXtrinsic
X-1= Warfarin
Red cell fragmentation + polychromasia?
MAHA- microangiopathic haemolytic anaemia
- can be due to HUS- ecoli (if + renal impairment)
What is the best test to use for sickle cell disease?
HPLC- haemoglobin high performance liquid chromatography (of whole blood lysate)
- confirm presence of HbS
Macroovalocytes and hypersegmented neutrophils?
B12/folate deficiency
Excess of blasts with Auer rods?
Acute Myeloid Leukaemia
Where does erythropoiesis take place in embryo?
Spleen
Where does erythropoiesis take place at birth?
Bone marrow + liver/spleen if needed
Where does erythropoiesis take place in adults
Bone marrow of: Skull Ribs Sternum Pelvis Proximal head of femur etc. (more in children, progressive loss of sites in ageing)
What feature do stem cells have that allow them to remain in good numbers?
Self-renewal
When divide, one stays as stem cell and one differentiates
What happens to erythrocytes as they differentiate? (3)
Increased Hb
Decreased nuclear size + RNA
Decreased cell size
Describe platelet formation?
In megakaryocytes
Form in cytoplasm at periphery and bud off
What can raised neutrophils?
Infection
Trauma
Infarction
What are monocytes?
Precursors to macrophages
How to test for specific precursor cells and how does it work?
Immunophenotyping
Studies antigen expression on lymphoid cells
Where is bone marrow commonly aspirated from in adults?
Posterior iliac crests
RBC energy source?
Glycolysis (no mitochondria)
What is haemoglobin made up of?
1 haem group (porphyrin ring + Fe2+)
2 alpha, 2 beta globin chains
4O2
How are cells destroyed in the spleen?
Actively phagocytosed by macrophages
What do globin chains become after destruction?
Amino acids
What do haem groups become after destruction?
Bilirubin
How do RBC prevent Fe2+ becoming Fe3+?
Reduced by NADH from glycolysis
How do RBC prevent oxidative damage from free radicals?
Glutathione formed from NADPH
What is the rate limiting enzyme involved in the conversion of NADPH to glutathione?
G6PD
How is CO2 transported in blood?
Mostly bicarbonate (also bound to Hb or dissolved)
What is cooperative binding?
O2 binding changes Hb shape to make more binding easier
SIGMOID CURVE
How do small molecules binding to Hb affect O2 affinity and tissue O2 delivery?
e.g. H+, CO2, 2,3-DPG
O2 affinity decreased
More released to tissue
Redistributive causes of low blood count?
Portal hypertension- splenomegaly- blood trapped in spleen
Redistributive causes of high blood count?
Steroids redistribute neutrophils to centre of vessel
What is haematocrit a measure of?
Volume of RBCs as % of total blood volume
Do reticulocytes have a nucleus/RNA?
No nucleus
Still some RNA
Cause of microcytic RBCs?
Problem with haemoglobin production (cytoplasmic maturation)
Cause of macrocytic RBCs?
Problems with nuclear maturation (cell division)
In iron deficiency, what happens to transferrin levels?
Increase (apotransferrin- unbound)
Causes of iron deficiency?
Dietary
Blood loss
Pregnancy
Malabsorption
What increase in iron should be seen with iron replacement therapy?
7-10g/week
What is compensated haemolysis?
Increased RBC production so not anaemic
Ways of measuring haemolysis? (2)
Reticulocytes Breakdown products (increased)
What is extravascular haemolysis?
In spleen+ liver- organomegaly
Release porphyrin–>
JAUNDICE + GALLSTONES
(normal products in excess)
What is intravascular haemolysis and causes?
Destroyed within circulation:
- ABO incompatibility
- G6PD deficiency
- Falciparum malaria
What is released during intravascular haemolysis? (4)
Abnormal products:
- Free Hb in serum
- Hb + albumin complex
- Pink urine- free Hb (black if oxidised)
- Haemosideruria (iron protein in urine)
Warm autoimmune haemolysis?
IgG
Cold autoimmune haemolysis?
IgM
Diagnosis of autoimmune haemolysis?
Direct Coomb’s test- identify antibody bound to own RBCs- agglutination= +ve test
Other causes of autoimmune haemolysis? (2)
Haemolytic transfusion reaction
Haemolytic disease of newborn
Mechanical causes of haemolysis?
DIC HUS TTP Leaking heart valve- damage membrane Infections e.g. malaria
Name 1 acquired cause of abnormal RBC membrane leading to haemolysis?
Vitamin E deficiency
Pathology of hereditary spherocytosis?
Mutations in membrane proteins that maintain flexibility/integrity- form spherical shape and spleen destroys
Features of G6PD deficiency?
X linked- men only
Can’t generate ATP in RBCs
In haemolysis, what happens to serum haptoglobins?
Decreased (bind the excess free Hb released)
What should all patients with a form of haemolytic anaemia be given and why?
Folic acid
Stimulate haematopoesis
Causes of microcytic anaemia? (7)
Iron deficiency Thalassemia Sideroblastic anaemia Anaemia of chronic disease Lead poisoning Alcohol/drugs Haemolysis (hereditary or acquired)
Causes of macrocytic anaemia? (5)
Pernicious anaemia Folate def. Alcohol/drugs Liver disease Hypothyroidism Marrow failure
What is HbA?
Normal Hb- 2 alpha 2 beta
What is HbA2?
2 alpha + 2 delta
What is HbF?
Foetal Hb- 2 alpha + 2 gamma
How is expression of globin changes regulated throughout life?
Genes arranged in order of expression- get turned on/off in right-left pattern
What are thalassemias?
Decreased globin synthesis (therefore low haemoglobin)
2 types of thalassemias?
Alpha thalassemia= alpha chains affected
Beta thalassemia= beta chains affected
Unbalanced accumulation of globin chains in thalassemias lead to..?
Toxic- leads to ineffective erythropoesis + haemolysis
Where are alpha genes found and how many are there?
Chromosome 16
4 genes
Where are beta genes found and how many are there?
Chromosome 11
2 genes
Alpha thalassemia affects which types of haemoglobin?
All types (all have alpha chains)
Symptoms of alpha thalassemia trait?
Asymptomatic
What is HbH disease?
One alpha gene left
Anaemia, Splenomegaly, Jaundice
What is Hb Barts Hydrops Fetalis?
No alpha genes- no HbA
Severe anaemia, cardiac failure, reduced growth, severe hepatosplenomegaly, skeletal abnormalities
most DIE IN UTERO
What is beta thalassemia caused by?
Point mutation
Only affects HbA
Symptoms of beta thalassemia major?
Pallor, failure to thrive, hepatosplenomegaly, skeletal changes- forehead/skull enlarged
Management of beta thalassemia major?
Regular transfusions
How do sickling disorders occur?
Point mutation in beta gene- makes HbS
How do sickling disorders cause anaemia?
HbS polymerises in low O2- damage RBC membrane
When might people with sickle trait suffer?
In severe hypoxia
Features of HbSS (sickle cell anaemia)?
2 abnormal genes- AR
Haemolysis + hyposplenism
What is sickle crisis?
Causes tissue infarction de to vascular occlusion
Pain- CNS, lung, marrow, hands, feet etc.
Precipitants of sickle crisis?
Hypoxia Dehydration Infection Cold Stress Fatigue
Management of sickle cell anaemia?
Prophylactic penicillin
Folic acid
Regular transfusion
Hydroxycarbamide
Diagnosis of sickle cell anaemia?
Blood film
Gel ELECTROPHORESIS
What does megaloblastic mean?
Abnormally large nucleated red cells with immature nuclei
failure to become smaller
Cause of megaloblastic anaemia?
Defects in DNA synthesis/nuclear maturation + more prone to apoptosis:
B12/folate deficiency
Sources of folate?
Veg, cereal, kidney beans, yeast
B12 absorption? (5)
- R-binder protein in mouth + stomach
- Intrinsic factor from parietal cells
- Pancreatic proteases in duodenum increase pH
- Breaks down R-binder, B12 binds to intrinsic factor
- Through to ileum- endocytosed
Body reserves of B12?
2-4 years
Causes of B12 deficiency?
Veganism Gastritis Bypass surgery Chronic pancreatitis Coeliac/Crohn's PERNICIOUS ANAEMIA
What is pernicious anaemia?
Autoimmune destruction of parietal cells- intrinsic factor deficiency- low B12 absorption
What is pernicious anaemia associated with?
Other autoimmune- hypothyroid, vitiligo, Addison’s
Where is folate absorbed?
Jejunum
Causes of folate deficiency?
Dietary Haemolysis Malignancy Coeliac/Crohn's Pregnancy Anti-convulsants
Body reserves of folate?
4 months
Clinical features of folate deficiency?
Anaemia Weight loss Diarrhoea Jaundice Developmental problems
Clinical features of B12 deficiency?
Sore (beefy) tongue
NEUROLOGICAL- neuropathy, dementia, column abnormalities
Autoantibodies in pernicious anaemia?
IF- anti-intrinsic factor
GPC- anti-gastric parietal cell
What is non-megaloblastic anaemia?
Due to red cell membrane changes (mature but large cells)
Causes of non-megaloblastic anaemia?
Alcohol
Liver disease
Hypothyroidism
Marrow failure
When might you get a false macrocytosis (false high MCV)? (2)
- Reticulocytosis- analysed as RBC but larger so give false large MCV
- Cold agglutinations- in lymphoma
What can cause normocytic normochromatic anaemia? (3)
- Acute blood loss
- Early iron def.
- Hypoproliferative- chronic disease, renal failure, hypothyroid, marrow failure
What is renal anaemia?
Lack of erythropoietin in renal failure
How does anaemia of chronic disease occur?
Inflammation causes upregulation of HEPCIDIN
- inhibits Fe absorption + release
- low erythropoiesis
Where does iron get absorbed?
Duodenum
What enhances iron absorption? (3)
- Haem iron (red meat)- easy to digest
- Ascorbic acid (vit C)
- Alcohol
What inhibits iron absorption? (3)
- Tannins (tea)
- Phytates (cereals, nuts, seeds)
- Calcium
In the duodenum, what converts Fe3 to Fe2?
Duodenal cytochrome B
What transports Fe2 into duodenal enterocyte?
DMT 1
How is iron exported from the duodenal enterocyte to bind to transferrin in the blood?
Ferroportin
What does hepcidin do?
Inhibit iron uptake- trap iron in duodenal cells
due to inflammation, iron overload etc.
How much iron is needed per day?
25mg
How much iron is in plasma?
4mg (rest in macrophages/hepatocytes)
Skin and nail signs of iron deficiency?
Koilonychia
Angular stomatitis
In iron overload, where is iron kept?
In parenchymal tissue e.g. liver, heart etc.
Oxidative stress causes organ damage
Mutation in hereditary heaemochromatosis?
HFE gene
Low hepcidin- high iron absorption
Bloods in hereditary heaemochromatosis?
Iron >5g
Transferrin sats >50%
Ferritin >300 micrograms/L
Presentation of hereditary heaemochromatosis?
In 40s-50s
Fatigue, joint pain, arthritis, cirrhosis, diabetes, cardiomyopathy, impotence etc.
Treatment of hereditary heaemochromatosis?
Weekly venesection (450-500ml) Keep ferritin <50micrograms/L
Secondary cause of iron overload?
Repeated transfusions
Thalassemias etc.
What does FFP contain?
Clotting factors
What does cryoprecipitate contain?
Fibrinogen
The genes responsible for ABO are on which chromosome?
9
Which plasma antibodies do blood group A- have?
anti-B antibody
anti-D antibody
Which plasma antibodies do blood group O have?
anti-A and anti-B antibodies
O blood can be given to?
Anyone
A blood can be given to?
A or AB
B blood can be given to?
B or AB
AB blood can be given to?
AB only
Group AB can receive blood from?
Any group
Which reagent is used to identify RBC antigens?
Antisera
Which reagent is used to identify plasma antibodies?
Reagent red cells
In tests to confirm a persons blood type, what is a positive test?
When agglutination occurs
In tests to confirm a COMPATIBILITY of blood transfusion (crossmatching), what is a good outcome?
NO agglutination means blood in compatible
Indications for RBC transfusion? (2)
Symptomatic anaemia
Major haemorrhage
Indications for platelets transfusion? (3)
Prophylaxis for surgery in thrombocytopenia
Bleeding in thrombocytopenia
Prophylaxis in bone marrow failure
Indications for FFP transfusion? (3)
Bleeding in coagulopathy
Prophylaxis for surgery in coagulopathy
Massive haemorrhage
Symptoms of acute reaction in transfusion?
Chills Rigors Rash/itch Flushing Fever Increased HR Decreased BP Collapse PAIN Sense of impending doom
Cause of acute haemolytic reaction in transfusion and type of hypersensitivity reaction?
ABO incompatibility- type 2 hypersensitivity
IgM + free Hb released
Cause renal failure!
Other cause of severe reactions in transfusion?
Bacterial contamination
What is TACO and symptoms?
Transfusion Associated Circulatory Overload
resp. distress, high BP, high JVP, +ve fluid balance
Risk factors for TACO?
Elderly HR failure Low albumin Renal impairment Fluid overload
Management of TACO?
O2
Furosemide
Slow transfusion rate
Steps in massive haemorrhage protocol? (4)
- Urgent blood samples
- ABCDE
- Transfuse blood component
- Thromboprophylaxis once controlled
What is shock?
Tissue hypoperfusion due to circulatory failure
What can shock lead to?
Anaerobic metabolism- metabolic acidosis + lactic acid
Eventually cellular NECROSIS
Recognition of shock? (5)
- BP, HR, RR etc.
- Mottling
- GCS
- Urine output <0.5ml/kg/hr
- Lactate levels
Which types of shock have cold, clammy peripheries?
Cardiogenic
Obstructive
Hypovolaemic
Which types of shock have warm, red peripheries?
Distributive (due to vasodilation)
Lifespan of platelets?
7-10 days
What is primary haemostasis?
Formation of platelet plug
Steps of primary haemostasis? (3)
- Endothelial damage= exposed collagen
- Release von Willebrand Factor (vWF) which attracts platelets- ADHESION
- Platelets secretes chemical causing AGGREGATION
Typical bleeding in primary haemostasis failure?
Spontaneous bruising Purpura (lower limbs) Mucosal bleeding- GI, nose, eye, menorrhagia Intracranial haemorrhage Retinal haemorrhage
What is secondary haemostasis?
Formation of fibrin clot- stabilise
Steps of secondary haemostasis? (6)
- Platelet plug secretes calcium to make -ve surface positive
- Attracts -ve clotting factors- activate each other
- Endothelium releases tissue factor- activates factor VII
- Activates factors V + Xa
- Activates prothrombin (factor IIa) to thrombin (activates factors VIII + IXa to AMPLIFY)
- Thrombin causes fibrinogen- FIBRIN
Typical bleeding in secondary haemostasis failure?
Into joints (ankles, knees etc.) and muscles
Prolonged PT=
factor VII deficiency
Prolonged APTT=
Haemophilia A/B
von Willebrand deficiency
Vascular causes of primary haemostasis failure? (4)
Age (low collagen)
Connective tissue disorders
Scurvy (vit C needed for collagen)
Vasculitis
Platelet function causes of primary haemostasis failure? (2)
Drugs- aspirin/anti-platelets, NSAIDs Renal failure (uraemia interrupts function)
Platelet number causes of primary haemostasis failure + examples? (3)
Low production- Marrow failure
High destruction- DIC, hypersplenism, immune thrombocytopenic purpura (ITP)
Consumption- bleeding
What is von Willebrand’s disease and what does it affect?
AD inherited deficiency of vWF
Affects platelet adhesion (primary haemostasis)
Why do men often have undiagnosed von Willebrand’s disease?
Asymptomatic (women will have menorrhagia)
Which other clotting factor is affected in von Willebrand’s disease?
Factor VIII low
vWF normally carries and protects it
Causes of multiple clotting factor deficiency? (4)
Liver failure (no synthesis)
Vitamin K deficiency (no carboxylation of factors)
Warfarin
DIC
What is DIC?
Excessive and inappropriate activation of haemostasis
Causes microvascular thrombus in organs- end organ failure + clotting factor consumption (bleeding)
Why is vitamin K important?
Carboxylation of glutamic acid to make factors II, V, IX, X + protein C + S
Causes of vitamin K deficiency?
Poor diet
Malabsorption
Obstructive jaundice
Haemorrhagic disease of newborn
When can DIC occur?
Trauma Sepsis Burns Meningitis Cancer Hyovolaemic shock
What happens to PT and APTT in multiple clotting factor deficiency?
Both prolonged
What else is raised in multiple clotting factor deficiency?
D-dimers (fibrin degradation products)
high in DIC) (low in liver disease
What is haemophilia A?
X linked disorder causing prolonged bleeding due to factor VIII deficiency
(x5 as common as B)
What is haemophilia B?
X linked disorder causing prolonged bleeding due to factor IX deficiency
Why does haemophilia cause prolonged bleeding?
Can’t amplify clotting system
Symptoms of haemophilia?
Recurrent haemarthroses
Soft tissue bleeds
++ bleeding in surgery and dental extractions
How do recurrent haemarthroses occur?
One bleed increases the risk of another due to neovasculisation af the synivium
In haemophilia, which blood test will be abnormal?
APTT will be prolonged
In venous system, what kind of clots are formed?
FIBRIN rich clots
NO platelet activation
Virchows triad applies to Venous system. What are the components?
vessel Wall (valves cause sluggish flow)
Hypercoaguability
Stasis
(WH Smith)
Signs of PE? (4)
SOB
Pleuritic chest pain
Rub
Hypoxia
Main differential of DVT?
Cellulitis
Risk factors for DVT/PE? (13)
Age Marked obesity Pregnancy (high clotting factors) Puerperium Smoking Oestrogen therapy Previous DVT/PE Surgery/Trauma Malignancy Paralysis Infection IV drug use/PIC lines Thrombophilia
Diagnosis of DVT? (4)
Peripheral pulses
Doppler USS
D dimer (raised in other things- -ve in low risk= exclude DVT)
Scoring systems
Treatment of DVT?
TED stockings Early mobilisation Physiotherapy Heparin Rivaroxaban Warfarin
What is thrombophilia?
Deficiency in naturally occuring anticoagulants causing increased TENDENCY TO THROMBOSE (high coagulation activity)
What are the naturally occuring anticoagulants?
Antithrombin- acts on thrombin and Xa, IX, XI, XII
Protein C+S- acts on V and VIII
Causes of hereditary thrombophilia? (3)
Factor V Leiden
Anti-thrombin deficiency
Protein C/S deficiency
What is Factor V Leiden?
Mutation of factor V stopping protein C binding and having its inhibitory effect–> overdrive leads to hypercoaguability
When should hereditary thrombophilia be considered? (4)
VTE <45 (esp men)
Recurrent VTE
Unusual VTE e.g. arm
FH of VTE or thrombophilia
Name a cause of acquired thrombophilia?
Anti-phospholipid syndrome (higher risk than inherited causes)
4 features of anti-phospholipid syndrome?
Activation of primary + secondary coagulation
Recurrent thrombosis
Recurrent pregnancy loss
Mild thrombocytopenia (ITP)
What is anti-phospholipid syndrome associated with? (4)
Autoimmune disorders
Lymphoproliferative disorders
Viral infections
Drugs
Treatment of thrombosis in anti-phospholipid syndrome?
Aspirin + warfarin
In general, what do anti-coagulants do?
Stop FURTHER clotting from occuring/breaking off
Target fibrin clot formation
Indications for anti-coagulants?
Venous thrombosis
AF
How does heparin work?
Increases action of anti-thrombin to prevent amplification of coagulation (with immediate effect)
2 forms of heparin?
LMWH- maintain antithrombin + Xa complex to keep switched on
Unfractionated- needs lots of monitoring
How is heparin monitored?
APTT (unfractionated)
or
Anti Xa assay (LMWH)
Complications of heparin? (3)
Bleeding
Heparin induced thrombocytopenia
Osteoporosis after long-term
How is heparin reversed?
Stop- out of system in 12-24 hrs
Protamine sulphate
How does warfarin work?
Inhibition of vitamin K
Steps in starting warfarin therapy? (4)
- Initiation (Slow for AF, liver failure, elderly. Fast for acute thrombosis)
- Stabilisation
- Maintenance (same time each day)
- Monitoring- PT to calculate INR
What is a normal INR and the target for warfarin therapt?
0.9-1.2
Target= 2-3
Major adverse effects of warfarin therapy?
Haemorrhage:
mild- brusing, epitaxis, haematuria
severe- GI, intracerebral, low Hb
Name some drugs that increase warfarin effect?
Antibiotics Alcohol Amiodarone NSAIDS (GI bleeds) \+ pomegranate
In patients with metallic heart valves, which is the only anticoagulant that can be used?
Warfarin
How long should warfarin be stopped for before a surgery?
5-7 days
If INR is too high or there is major bleeding, how can the effect of warfarin be reversed? (3)
Omit dose(s) Oral vitamin K Clotting factors (factor concentrates)
How long does oral vitamin K take to work?
6 hours
What are DOACs?
Direct oral anticoagulants
DOACs: How do rivaroxaban, apixaban etc. work?
Activated factor X inhibitors (Xa-ban)
DOACs: How does dabigatran work and when can’t it be used?
Thrombin inhibitor
Avoid in renal failure
What is fragmin?
Dalteparin- another anticoagulant
In arterial system, what kind of clots are formed?
Platelet rich clots
Cause of arterial thrombosis?
Usually atherosclerosis, recruit foamy macrophages
Stable plaques are calcified. What can happen to unstable plaques?
Rupture + recruit platelets –> acute thrombosis
Prevention of arterial thrombosis + examples?
Anti-platelets e.g. aspirin, clopidogrel, dipyridamole, abciximab
How does aspirin work?
Inhibits cyclo-oxygenase so can’t produce thromboxane A2
How does clopidogrel work?
ADP receptor antagonist (reduce platelet aggregation)
How can the effects of anti-platelets be reversed in the case of severe bleeding?
Platelet infusion
What are myelocytes?
Precursor of neutrophils
Which cell layer are stem cells derived from?
Mesoderm
Where is bone marrow commonly aspirated from in children?
Tibia
How do cells exit the bone marrow?
Through fenestrations in the membranes- actively migrate down gradient into sinusoid
What is red marrow?
Haemopoietically active
What is yellow marrow?
Fatty, less cellular, inactive
More with age
What is the myeloid:erythroid ratio and what is the normal range?
neutrophil precursors:nucleated RC precursors
1.5:1 - 3.3:1
When might the myeloid:erythroid ratio reverse?
When increased erythroid production e.g. haemolysis, blood etc.
What is a stem cell niche?
The microenvironment in which stem cells are found, which interacts with stem cells to regulate stem cell fate (expansion, differentiation, dormancy)
Secondary lymphoid tissue?
Lymph nodes
Spleen
(tonsils)
In lymph nodes, where are B cells found?
Follicles (also where antigens are presented)
In lymph nodes, where are T cells found?
Trabeculae
Causes of lymphadenopathy? (6)
Infection (local- e.g. TB or generalised- e.g. virus) Vaccination Autoimmune Connective tissue disorder Malignancy Sarcoidosis
Which artery supplies the spleen?
Splenic artery from the coeliac axis
Which vein drains the spleen?
Splenic vein to the portal vein
The spleen is made up of red and white pulp. What is the function of each?
Red- sinusoids filters blood with marcophages
White- antigen presenting cells
3 components of hypersplenism?
Splenomegaly
Reduced cellular component in blood
Correction of bloods with splenectomy
Causes of hypersplenism? (6)
- Infection- EBV, malaria, TB
- Congestion- portal hypertension
- Haematological- ITP, haemolytic anaemia, leukaemia, lymphoma
- Inflammatory- SLE, RA
- Storage diseases
- Others- amyloid, tumour, cyst
Causes of hyposplenism? (4)
Splenectomy
Coeliac disease
Sickle cell disease
Sarcoidosis
When might Howell-Jolly bodies be seen and what are they?
Nuclear remnant in RBC
Seen in hyposplenism (splenectomy, sickle cell disease etc.)
Characteristics of malignant haematopoiesis? (4)
MONOCLONAL High numbers of abnormal/dysfunctional cells - increased proliferation - decreased differentiation - decreased maturation - decreased apoptosis
Why is malignant haematopoiesis monoclonal?
Due to mutated regulatory genes (driver mutations) being selected in evolution- one lineage chosen
Feature of acute haematological malignancy?
Primitive cells/precursors
Feature of chronic haematological malignancy?
Differentiated/mature cells
What can chronic lymphocytic leukaemia affect?
Lymph and blood
Features of acute leukaemias?
AGGRESSIVE- usually younger people
Large cells + nuclei with MATURATION defects- blasts
What is the most common childhood cancer and how does it present?
Acute Lymphoblastic Leukaemia (ALL)- malignant lymphoblasts!
Marrow failure, bone pain (rapid marrow expansion)
Which type of acute leukaemia is more common in elderly people (>60) and how does it present??
Acute Myeloid Leukaemia (AML)
May be de novo or following another haematological disorder
Marrow failure
How to differentiate between AML + ALL
Immunophenotyping
Treatment of AML + ALL?
Chemotherapy (most will go into remission but many will relapse again)
Stem cell transplant
Which pathology of lymph nodes will not be hard, but soft/rubbery?
Lymphoma
Which pathology of lymph nodes will not be smooth, but irregular?
Metastatic cancers
Which pathology of lymph nodes will cause overlying skin inflammation?
Bacterial infection
Which pathology of lymph nodes will cause the node to be tethered?
Metastatic cancers, sometimes bacterial infections
Ways to biopsy lymph nodes?
Core biopsy or FNA
or
CT guided biopsy of whole node
What tests are done to a lymph node biopsy?
Histology Immunohistochemistry- for pattern of proteins Immunophenotyping Cytogenetic analysis Molecular analysis
What is lymphoma?
Neoplasm of mature lymphocytes (more commonly B cells) in lymphoid tissue
What is Hodgkin’s lymphoma?
More common in younger patients
Good prognosis
Had REED-STERNBERG (RS) CELLS
Treatment of Hodgkin’s lymphoma?
Early- radiotherapy
Late- chemotherapy
What is Non-Hodgkin’s lymphoma?
No reed-sternberg cells
In elderly
Low or high grade
Prognosis of Non-Hodgkin’s lymphoma?
Low grade- incurable but indolent (7-10 years)
High grade- 30-40% survival
Treatment of Non-Hodgkin’s lymphoma?
Low grade- palliative + supportive chemo
High grade- combined chemo
Presentation of lymphoma?
PAINLESS lymphadenopathy Fever, weight loss, drenching night sweats Itch (no rash)- hot water Alcohol induced pain Hepatosplenomegaly Bone marrow failure
How is the variable Ig segment on antibodies generated?
VDJ segment of gene (many combinations)
Fate of B cells after lymph node?
Circulate as memory B cells
or
Return to marrow as plasma cell
Immunoglobulins contain?
2 heavy + 2 light chains
Which immunoglobulin is a pentamer?
IgM
Which immunoglobulin is a dimer?
IgA
What is the marker of underlying clonal B cell disorder, and how is it detected?
Paraprotein (MONOclonal immunoglobulin in urine/blood)
by ELECTROPHORESIS
What is Bence Jones protein?
Immunoglobulin light chain in urine if made in excess (leaks into urine)
Causes of paraproteinaemia? (5)
MGUS Myeloma Amyloidosis Lymphoma Waldenstrom's macroglobulinaemia
What is myeloma and how is it classified?
Monoclonal proliferation of plasma cells (activated B cells)
Classified by type of antibody produced
Why does myeloma affect bones and what does it cause?
Causes dysregulated OSTEOCLAST activity
- LYTIC bone lesions
- bone pain
- pathological fracture
- hypercalcaemia
Symptoms of myeloma due to paraproteins?
Renal failure (CAST NEPHROPATHY- clumping of light chains)
Amyloidosis
Hyperviscosity
Immune suppression
Investigations of myeloma?
FBC, PV, U+E Blood film Serum Ca Marrow aspirate DEXA scan/Xray Urine- BJP
What would a blood film show in myeloma?
Rouleaux
Treatment of myeloma?
Not cureable Chemotherapy Dexamethasone/pred Stem cell transplant New- thalidomide, bortezomib, lenalidomide BISPHOSPHONATES
How is response to treatment monitored in myeloma?
Paraprotein level
What is monoclonal gammopathy of undetermined significance (MGUS)?
Paraprotein <30g/L (less than myeloma)
NO evidence of myeloma/organ damage
BENIGN (small chance of myeloma progression)
What is AL amyloidosis?
(Amyloid light-chain amyloidosis)
Abnormal plasma cell- mutation in light chain- form insoluble beta sheet
Which stain is used to confirm amyloidosis?
Congo Red Stain (appear apple green)
Treatment of amyloidosis?
Chemotherapy (switch off light chain supply)
What is Waldenstrom’s Macroglobulinaemia and what paraprotein is produced?
Clonal disorder of immediate cell between lymphocytes + plasma cells
IgM paraprotein
Presentation of Waldenstrom’s Macroglobulinaemia?
Lymphadenopathy Splenomegaly Marrow failure Neuropathy Night sweats, weight loss HYPERVISCOSITY- bleeding, fatigue, cardiac failure
Treatment of Waldenstrom’s Macroglobulinaemia?
Chemo
PLASMAPHERESIS- remove own and replace with donor plasma
What is pancytopenia?
Deficiency in all blood cell lineages Low RBC Low platelets Low white cells (generally excludes lymphocytes)
Cause of pancytopenia due to reduced production?
Marrow failure
Inherited causes of marrow failure?
Rare
Fanconi’s anaemia- imparied haemopoiesis, congenial abnormalities, cancer pre-disposition
Acquired causes of marrow failure?
Primary- idiopathic aplastic anaemia, myelodysplastic syndromes (MDS), acute leukaemia
Secondary- drugs, B12/folate def., infiltrative, viral
How does idiopathic aplastic anaemia affect marrow?
Reduced red marrow
What can myelodysplastic syndromes (MDS) lead to?
AML
Cause of pancytopenia due to increased destruction?
Hypersplenism- blood trapped + increased phagocytic activity
Causes of hypersplenism?
Portal hypertension
Rheumatoid arthritis
Splenic lymphoma
Presentation of pancytopenia?
Anaemia
Infections
Bleeding
Investigations of pancytopenia?
FBC + retic count Blood film LFT B12 + folate Autoantibodies Aspirate
When is marrow hypocellular?
Aplastic anaemia
When is marrow hypercellular?
B12/folate deficiency
Hypersplenism
Myelodysplastic syndromes
Treatment of pancytopenia?
Red cell + platelet transfusion
Antibiotic prophylaxis
Marrow transplant
Consider splenectomy
What are myeloproliferative disorders (MPD)?
Clonal proliferations (increased production) or one/more lineages MATURATION preserved
Name some myeloproliferative disorders (MPD)?
Red cells- polycythaemia rubra vera
Platelets- essential thrombocythaemia
White cells- CML
Reactive fibroblasts- myelofibrosis
Which myeloproliferative disorders are BCR-ABL1 positive?
CML
What bloods would causes suspicion of myeloproliferative disorders?
High granulocytes High RBC/Hb High platetetls Eosinophilia/basophilia May have splenomegaly
What does chronic myeloid leukaemia cause?
Proliferation of myeloid (granulocytes + platelets)
Presentation of chronic myeloid leukaemia?
Peak 40-50 years Often asymptomatic Splenomegaly B symptoms Gout Small vessel problems (e.g. eyes)
3 phases of chronic myeloid leukaemia?
- Chronic phase
- Accelerated phase
- Blast phase (crisis)- like acute leukaemia
Hallmark of CML?
PHILADELPHIA CHROMOSOME- produces BCR-ABL 1 gene
which is a tyrosine kinase
Investigation of CML and findings?
FBC- normal/low Hb, leucocytosis, neutrophilia, myelocytes, thrombocytosis,
Treatment of CML?
Imatinib- tyrosine kinase inhibitor
Common features of BCR-ABL1 negative MPD? (6)
Asymptomatic or B symptoms Gout Splenomegaly Marrow failure Thrombosis (A+V)
What polycythaemia rubra vera?
High Hb/haematocrit + ERYTHROCYTOSIS
may also cause increased WCC/platelets
Causes of secondary polycythaemia?
Smoking
Chronic hypoxia
EPO-secreting tumours
What is pseudopolycythaemia?
Apparent increase in RBCs due to reduction in plasma volume
e.g. dehydration, diuretic, obesity
Clinical features of polycythaemia rubra vera?
55-60 yrs
Headache, fatigue, dizziness, sweating, plethora, ITCH AFTER WARM WATER
Splenomegaly
Thrombosis + bleeding
What is polycythaemia rubra vera associated with?
JAK2 mutations in 95%
Kinase- loss of auto-inhibition of erythropoiesis (increased)
Treatment of polycythaemia rubra vera?
Aspirin 75mg/day
Venesection
Hydroxycarbamide (oral chemo)
What is essential thrombocythaemia?
Uncontrolled production of abnormal platelets
Leading to thrombosis
Presentation of essential thrombocythaemia?
Peak 50-70yrs
Asymptomatic
Burning in hands/soles, cold peripheries, headache, dizziness, digital ischaemia, gangrene
Epitaxis, menorrhagia
What is essential thrombocythaemia sometimes associated with?
acquired vWF deficiency due to excess platelets
Leads to bleeding
Investigation of essential thrombocythaemia?
Exclude reactive causes
Exclude CML
JAK2 mutation (50%)
CALR in those without JAK2
Treatment of essential thrombocythaemia?
Aspirin
Hydroxycarbamide (oral chemo)
What is myelofibrosis?
Progressive scarring (fibrosis) in bone marrow
2 causes of myelofibrosis?
Idiopathic
or
Secondary (transformed) for PRV or ET
Presentation of myelofibrosis?
> 50s (60-70)
Extramedullary haemopoiesis (liver + spleen
Marrow failure
Fatigue, weight loss, itch
Investigations of myelofibrosis + findings? (4)
Blood film (leukoerythroblastic film + TEARDROP RBCs)
Dry aspirate on attempt
Trephine biopsy (stain for fibrosis)
JAK2/CALR mutation
How do teardrop RBCs occur?
Damaged when squeezing through sclerotic bone marrow
Treatment of myelofibrosis?
Blood/platelet transfusion Antibiotics Stem cell transplant Consider splenectomy JAK2 inhibitor- Ruxolitinib
Name a JAK2 inhibitor?
Ruxolitinib
How does cytotoxic chemotherapy work?
Damage DNA which promotes apoptosis
Name some cell cycle specific (tumour specific) drugs? (3)
Methotrexate
Hydroxyurea
Mitotic spindle inhibitors
Name some non-cell cycle specific drugs? (3)
Alkylating agents
Platinum derivatives
Cytotoxic antibiotics
Nucleated red cells in blood of a newborn baby may suggest?
NORMAL
What are Heinz bodies and some causes? (4)
Formed by damage to Hb (usually oxidative)
- G6PD def
- NADPH def
- Chronic liver disease
- Alpha thalassemia
Name some anticoagulants and what are they used for?
Warfarin, Heparin, DOACs
Venous (red) thrombosis
Name some antiplatelets and what are they used for?
Aspirin, Clopidogrel
Arterial (white) thrombosis
Giving folate in B12 deficiency can lead to what?
Demyelination!!
make sure to find out cause of anaemia!
How does methotrexate affect heamatopoiesis?
Inhibits folate (monitor levels/give folic acid)
Smudge cells?
CLL
t(8;14)?
Burkitt’s Lymphoma
What are schistocytes seen in?
DIC, TTP
Which clotting factors are used up first in DIC?
Consume factors V + VIII (and platelets) first
Deficiencies of which clotting factors will cause prolonged PT and APTT?
II, V, X (common pathway factors)