haem Flashcards
What are the criteria smouldering myeloma?
paraprotein >30g/l
>10% plasma cells in BM
no related organ or tissue impairment
doesn’t require treatment, monitoring needed
What is MGUS?
monoclonal gammopathy of unknown significance
a premalignant condition that makes paraprotein
increases risk of myeloma and lymphoma
What can come before multiple myeloma?
MGUS
Smouldering myeloma
all plasma cell dyscrasias
Do you treat MGUS and smouldering myeloma?
Not yet
Just monitor
What is the risk of MGUS and smouldering myeloma progressing to multiple myeloma?
MGUS: 1%
SM: 20% in first year, then 5%
What is the criteria for MGUS?
Paraprotein <30 g/L.
Monoclonal plasma cells in bone marrow <10%.
Absence of myeloma-related organ or tissue impairment
What investigations would be carried out for multiple myeloma?
FBC (anaemia or leukopenia in myeloma)
Calcium (raised in myeloma)
ESR (increased in myeloma)
Plasma viscosity (increased in myeloma)
U&E (for renal impairment)
Serum protein electrophoresis (to detect paraprotein)
Serum-free light-chain assay (to detect abnormally abundant light chains)
Urine protein electrophoresis (to detect the Bence-Jones protein)
What are the main presentations in multiple myeloma?
C – Calcium (elevated)
R – Renal failure
A – Anaemia
B – Bone lesions and bone pain
What are the symptoms of multiple myeloma?
Persistent bone pain and pathological fractures
Unexplained fatigue and weight loss
Fever of unknown origin
Hypercalcaemia
Anaemia
Renal impairment
Dizziness, confusion, blurred vision, headaches, epistaxis, cerebrovascular event
What is myeloma?
a type of cancer affecting the plasma cells (differentiated B lymphocytes) in the bone marrow.
Leads to accumulation of malignant plasma cells
proliferation disorder of plasma cells
What is multiple myeloma?
myeloma affecting multiple bone marrows in the body
What are some differentials for multiple myeloma?
MGUS
Amyloid light-chain (AL) amyloidosis.
Solitary plasmacytoma.
B-cell non-Hodgkin’s lymphoma
Chronic lymphocytic leukaemia
Examples of triplet drug combos for initial therapy in multiple myeloma
- VTD: Bortezomib, thalidomide, and dexamethasone
- KRD: carfilzomib, lenalidomide and dexamethasone
- RVD: lenalidomide, bortezomib and dexamethasone
What does allogeneic stem cell transplant mean?
stem cells from a healthy donor
What are autologous stem cells?
derived from the patient
Treatment for healthy patients, patients younger than 65-70, with multiple myeloma
Induction drug therapy
Stem cell transplant
Possible complications of multiple myeloma
Infection
Bone pain and fractures
Renal failure
Anaemia
Hypercalcaemia
Peripheral neuropathy
Hyperviscosity syndrome
Venous thromboembolism
What is lymphoma?
malignancies of the lymphoid system
disease may arise at any site where lymphoid tissue is present
What is anaemia?
haemoglobin <130 g/Lin men aged ≥15 years
<120 g/L in non-pregnant women aged ≥15 years
<110 g/L (11 g/dL) in pregnant women
What can cause a decreased production of RBCs?
Iron, folate and B12 deficiencies
Bone marrow failure
What can cause RBC loss?
Bleeding
Haemolysis
What is the most common cause of anaemia worldwide?
Iron deficiency
What is the aetiology of iron def anaemia?
Inadequate iron intake
Impaired iron absorption
Blood loss
Increased need (e.g. growth in children)
What helps to absorb B12?
Intrinsic factor
B12 must bind to IF to be absorbed in terminal ileum
How much iron do men and postmenopausal women lose daily?
1mg
How much iron do menstruating women lose daily?
2mg
Key presentations of iron deficiency anaemia
fatigue
dyspnoea on exertion
pica
restless legs syndrome
nail changes
What are the symptoms of iron deficiency anaemia?
Fatigue.
Shortness of breath on exertion.
Palpitations.
Sore tongue and taste disturbance.
Mouth ulcers
Changes in the hair/hair loss.
Pale skin and conjuctiva
Pruritus.
Headache.
Tinnitus.
Angina, which can occur if there is pre-existing CHD
What type of anaemia does iron deficiency cause?
microcytic hypochromic anaemia
characterised by small and pale red blood cells on blood film.
What would the MCV value be in ID anaemia?
less than 80 fL
What investigations would you do for ID anaemia?
FBC (Hb and MCV)
Serum iron (low)
Total iron binding capacity (high, means more space for iron to be bound)
Transferrin saturation (low)
Ferritin (low)
What are some risk factors for ID anaemia?
pregnancy
vegetarian and vegan diet
menorrhagia
hookworm infestation (via blood loss)
chronic kidney disease
coeliac disease
gastrectomy/achlorhydria (low gastric acid so harder for iron to be absorbed)
NSAID use (causes gastric ulcers)
Differentials for ID anaemia
Thalassaemia
sideroblastic anaemia
Anaemia of chronic disease
Lead poisoning
What’s the initial treatment for ID anaemia?
daily oral iron replacement therapy
Side effects of iron supplements for IDA
Constipation
Black stools
Diarrhoea
Heartburn
Nausea
Abdominal/epigastric pain
Treatment for patients who can’t tolerate oral iron in IDA
IV iron therapy
How do you monitor ID anaemia?
Retest Hb within 4 weeks of starting treatment
FBC within 2-4 months if responsive to treatment
What are some complications of ID anaemia?
Cognitive and behavioural impairment
Impaired muscular performance
High output heart failure in severe anaemia
Preterm delivery (risk if anaemia in first 2 trimesters)
What is microcytic anaemia?
anaemia with an MCV of less than 80
Why does microcytic anaemia occur?
As there is a lack of haemoglobin, an extra division of RBCs occurs to maintain adequate Hb concentration
This results in smaller and paler (hypochromic) RBCs
What is the most common cause of microcytic anaemia?
Iron deficiency anaemia
What is the mean corpuscular volume?
average size and volume of a red blood cell
used in classifying anaemia
Which anaemias are microcytic?
Iron def
Sideroblastic
Thalassaemia
Anaemia of chronic disease
Which anaemias are normocytic?
anaemia of chronic disease/inflammation
haemorrhagic
haemolytic
leukaemias/ other cancers
myeloproliferative
What is the MCV for microcytic anaemias?
less than 80fl
What is the MCV for normocytic anaemias?
80-95fL
What is the MCV for macrocytic anaemia?
above 95 fl
Which deficiencies are megaloblastic?
B12
Folate
In macrocytic anaemias, what is the difference between megaloblastic and non-megaloblastic?
Megaloblastic has a problem in DNA synthesis and repair, non-meg doesn’t
Which anaemias are non-megaloblastic?
chronic alcohol use
liver disease
hypothyroidism
MDS
haemolysis and haemorrhage
What are non-specific symptoms of anaemia?
Pallor
Fatigue and weakness
Dyspnea
Headaches
Dizziness
What is the difference in the time taken to develop B12 and folate deficiency?
B12 deficiency takes years
Folate deficiency can happen much faster, e.g. weeks
What type of anaemia is B12 deficiency?
Macrocytic megaloblastic
What is the aetiology of B12 deficiency?
- Pernicious anaemia
- Insufficient dietary B12
- Medications that reduce B12 absorption (e.g. PPIs, metformin, anticonvulsants)
- Malabsorption in GI tract: e.g. Crohn’s, coeliac
What medications can lead to B12 deficiency?
PPIs
H2 receptor antagonists
Metformin
Anti-convulsants
What are the risk factors for B12 deficiency?
- Age >65 years
- history of gastric surgery (gastrectomy, or bypass for obesity)
- vegan and vegetarian diet
- Chronic GI illnesses (e.g., Crohn’s disease or coeliac disease
- Use of known causative medications (proton-pump inhibitors, H2 receptor antagonists, metformin, anticonvulsants)
- Pregnancy
What are some differential diagnoses for B12 deficiency?
Folate deficiency
Pernicious anaemia
MDS
Peripheral/ diabetic neuropathies
Crohn’s, coeliac
MS
Hypothyroidism
Alcoholic liver disease
What are the key presentations in B12 deficiency?
Paraesthesia
Cognitive changes
Visual disturbance
Numbness
neurological symptoms differntiate it from folate deficiency
What is haemolytic anaemia?
Reduction in red cell lifespan due to increased red blood cell destruction
Symptoms of B12 deficiency
Fatigue and muscle weakness
Neurological symptoms (paraesthesia, numbness)
Oral ulcers
Vision disturbances
Psychological symptoms
Pallor
Why is B12 needed and what does deficiency mean in this case?
Required for DNA synthesis and fatty acid synthesis
Co-factor for methylmalonyl-Co-A, methionine synthesis (important in neural function) and DNA synthesis
rapid sphingolipid turnover in myelin sheath means deficiency can cause neurological symptoms
What is a low serum b12 level?
<200 picograms/mL
What investigations would you order for b12 deficiency and what would they show?
FBC: MCV high, haematocrit low
peripheral blood smear: megalocytes, hypersegmented polymorphonucleated cells
serum vitamin B12: <200 picograms/mL
reticulocyte count: low
Initial management for b12 deficiency
IM hydroxocobalamin 3 times weekly for two weeks
(or alternate days until there is no further improvement in neurological symptoms)
Management for b12 deficiency
IM hydroxycobalamin injections 3x a week for 2 weeks
Follow up injections of 1mg every 2-3 months
Complications of B12 deficiency
Neurological deficits
Haematological deficits
Psychological conditions and cognitive impairment
If during pregnancy: low birth weight and preterm delivery
Difference between b12 and folate deficiency
B12 takes years and has neurological symptoms
Folate takes weeks and has no neuro symptoms
What is folate (B9) deficiency?
megaloblastic anaemia, with absence of neurological signs.
What foods is folate present in?
Green leafy vegetables, legumes, folic acid in fortified cereal-grain products
Who does folate deficiency most commonly affect?
Young children
Older adults
Pregnant women
What is the aetiology of folate deficiency?
Inadequate dietary intake
Malabsorption
Increased requirement (pregnancy, growth)
Increased loss of folate: chronic dialysis
Medications: anticonvulsants (e.g. phenytoin), sulfasalazine, methotrexate
What medications can cause folate deficiency?
anticonvulsants (e.g. phenytoin)
sulfasalazine
methotrexate
How does folate deficiency affect cells?
Folate deficiency impairs DNA synthesis and repair, which holds back cell division and leads to apoptosis of haematopoietic cells in the marrow.
The loss of erythropoietic cells causes anaemia
folate is needed for nitrogen base synthesis
What happens to cells in megaloblastic anaemia?
Megaloblastic anaemia results from impaired DNA synthesis, preventing the cells from dividing normally.
Rather than dividing, they grow into large, abnormal cells
What are the risk factors for folate deficiency?
low dietary folate intake
age >65 years
alcohol-use disorder
pregnancy or lactation
premature infant
intestinal malabsorption disorders
use of certain medications
infantile exclusive intake of goats’ milk (no folate)
congenital defects in folate absorption and metabolism
Symptoms of folate deficiency
loss of appetite and weight loss
fatigue
shortness of breath
dizziness
pallor
dyspnea
tachycardia
What would be seen on a peripheral blood smear in folate and b12 deficiency?
Macrocytic anaemia and hypersegmented neutrophils
What investigations would you order for folate deficiency?
Serum folate (low) and serum b12 (normal)
Peripheral blood smear (Macrocytic anaemia and hypersegmented neutrophils)
FBC (low Hb, elevated MCV)
reticulocyte count (low)
Why is it important to test patients for both b12 and folate deficiency?
Underlying B12 deficiency should be ruled out before implementing therapy with folic acid, because folic acid may mask neurological complications of untreated vitamin B12 deficiency
What does a reticulocyte count show?
indicates red blood cell production
Differential diagnoses for folate deficiency
B12 deficiency
Alcoholic liver disease
Thiamine-responsive megaloblastic anaemia
Hypothyroidism
Drug-induced macrocytosis
MDS
How would you manage folate deficiency?
Once B12 deficiency ruled out:
Oral folic acid replacement
How can you prevent folate deficiency in pregnancy?
Folic acid supplementation
What are some possible complications of folate deficiency?
Foetal neural tube deficits
Haematological deficits
Progression of neuropathy from masked B12 deficiency
How long do folate stores in the body last?
4 months
What lab results would you get for anaemia of chronic disease?
Low transferrin sats
High ferritin levels
Normal/low TIBC
Low serum iron
Microcytic or normal
What happens in sideroblastic anaemia?
Abnormality in haem synthesis pathway
Iron stores normal
What would be seen on a peripheral blood smear for sideroblastic anaemia?
basophilic stippling
pappenheimer bodies
What can cause sideroblastic anaemia?
Congenital (X-linked)
Exposure to lead
Medications, e.g. isoniazid for TB
Where are the genes for alpha globin found?
Chromosome 16
What is alpha-thalassaemia?
a group of disorders of Hb synthesis, caused by mutations or deletions in at least one of the four alpha-globin gene
leading to variably impaired alpha-globin chain production, with accumulation of beta-globin chains
symptom severity depends on number of genes affected
What are the different alpha-thalassaemias?
1 affected alpha globin gene: silent carrier
2 affected: alpha thalassaemia trait
3 affected: HbH disease
4 affected: Alpha T major, Hb Bart hydrops fetalis syndrome
How does hypoxia occur in alpha thalassaemia?
HbH and Hb Bart’s have a high affinity for oxygen so don’t release it to tissues
The hypoxia causes an increase in RBC production and therefore bone marrow, liver and spleen enlargement
Pathophysiology of alpha thalassaemia
accumulation of excess unmatched beta-globin chains, which aggregate, causing oxidant and mechanical damage to the affected red cells and leading to their premature destruction
What would be seen on a peripheral blood smear in alpha thalassaemia?
Microcytosis, hypochromia, target cells
What investigations would be done for alpha-thalassaemia and what do they show?
Hb: normal to low
MCV: low
MCH: low
RBC count: increased
Serum iron and ferritin: normal/ elevated
Differentials for alpha-thalassaemia
Iron deficiency anaemia
Beta-thalassaemia
Anaemia of chronic disease
Lead poisoning
Sideroblastic anaemias (SA)
B12 deficiency anaemia and Folate deficiency
Other haemolytic anaemias
How would HbH disease present?
Anaemic
very low MCV and MCH
splenomegaly
variable bone changes.
How does alpha-thalassaemia trait (2 genes affected) present?
mild anaemia and low red blood cell (RBC) indices
How would severe thalassaemia present?
Hepatosplenomegaly
Bony deformities (frontal bossing, prominent facial bones, and dental malocclusion)
Marked pallor
Jaundice.
Exercise intolerance, cardiac flow murmur or HF secondary to severe anaemia
Do silent carriers or alpha-thalassaemia trait require treatment and monitoring?
No
Should not be treated with iron therapy unless iron deficiency is proved
HbH should be monitored for complications
What is the outlook for alpha-thalassaemia major?
Without intervention, the fetus is subject to severe hypoxia, leading to hydrops fetalis and the associated morbidity and mortality
Infant can survive into childhood if mother receives intrauterine transfusions, then child has lifelong transfusions
What is beta thalassaemia?
Beta-thalassaemia is an inherited blood disorder caused by mutations of the beta-globin gene that results in ineffective erythropoiesis
Where is the beta-globin gene located?
Chromosome 11
What is HbA?
Adult haemoglobin
2 alpha 2 beta chains
What is HbF?
Foetal haemoglobin
Why does Beta-thalassaemia major not present until the first 3-6months of life?
HbF still present until this point
HbF can also use up some of the free alpha chains
What is the pathophysiology of beta-thalassaemia?
(haemolysis and hypoxia)
Free alpha chains accumulate within RBCs, damaging RBC membrane.
Causes haemolysis in bone marrow or RBC to be destroyed by macrophages in spleen.
Haemolysis causes Hb to spill into plasma, Haem is recycled into iron and unconjugated bilirubin = jaundice and secondary haemochromatosis
Haemolysis leads to hypoxia as fewer RBCs.
Hypoxia signals BM, liver and spleen to increase RBC production, causing BM containing bones (in skull and face), liver and spleen to all enlarge
What is the pathophysiology behind Hb Bart’s Hydrops Fetalis?
gamma chains form tetramers in absence of alpha chains
Hb Bart’s has very high affinity for oxygen.
Tissues get no oxygen leading to high output cardiac failure, splenomegaly and oedema across body.
Incompatible with life
What are the different types of beta-thalassaemia?
1 mutated beta globin gene: B-T minor (B+) or (B0), asymptomatic
2 mutated beta globin genes code for reduced synthesis (B++): B-T intermedia
2 mutations where no beta globin is produced (B00): B-T major
Classification of B-T minor (BT trait)
Slightly anaemic
low MCV and MCH
clinically asymptomatic.
Classification of B-T intermedia
-/βo or β+/β+)
high HbF, variable.
Anaemic
very low MCV and MCH
splenomegaly
variable bone changes
variable transfusion dependency
Classification of B-T major
(genotype -o/-o)
HbF >90% (untransfused)
Severe haemolytic anaemia
very low MCV and MCH
hepatosplenomegaly
chronic transfusion dependency
What would a peripheral blood smear show for beta-thalassaemia?
microcytic red cells
tear drops
microspherocytes
target cells
some fragments
large number of nucleated red cells
What investigations would you do for beta-thalassaemia?
- Peripheral blood smear: microcytic red cells, tear drops, target cells
- FBC: microcytic anaemia, all blood counts may be lower with increasing splenomegaly
- LFTs in intermedia and major: elevated total and unconjugated bilirubin
- Reticulocyte count: elevated
Differentials for beta-thalassaemia
Congenital dyserythropoietic anaemia (CDA)
Pyruvate kinase (PK) deficiency
Mild iron deficiency anaemia
Alpha-gene mutations
Haemolytic anaemia
Anaemia of chronic disease
How would you manage thalassaemia?
Mild and asymptomatic don’t tend to require treatment. Avoid unnecessary iron supplementation to avoid iron overload
In very severe cases, consider RBC transfusion
Complications of thalassaemia
Iron overload
Growth delays (alpha)
Gallstones
Splenomegaly
Leg ulcers
MSK complications (beta)
Gout (beta)
Transfusion related complications
Prognosis for beta-thalassaemia
Beta-thalassaemia trait: normal
Beta-thalassaemia intermedia: cosmetic changes, variable iron overload
B-t major: fatal within a few years if untreated, transfusions can greatly increase quality of life and expectancy
What is the pathophysiology of multiple myeloma?
Uncontrolled replication of plasma cells and secretion of antibodies
This produces diffuse bone marrow infiltration causing bone destruction and bone marrow failure.
There is also overproduction of a monoclonal antibody (‘paraprotein’) by the malignant plasma cells, detectable in serum and/or urine
What is the normal physiology of B cell differentiation?
B cells originate in bone marrow from haematopoietic stem cells
Migrate to lymphoid tissues
Activated by CD4 T cells and develop into plasma cells in the bone marrow
Plasma cells produce large quantities of antibodies
Why does hypercalcaemia develop in multiple myeloma?
Increase cytokine secretion (RANK-L) causes increased osteoclast activity
More calcium is released
Why does anaemia occur in multiple myeloma?
The cancerous plasma cells invade the bone marrow (bone marrow infiltration)
Suppression of the other blood cell lines, leading to anaemia (low haemoglobin), leukopenia (low white blood cells) and thrombocytopenia (low platelets).
Anaemia in myeloma is normocytic (normal size) and normochromic (normal colour)
What are the 4 types of leukaemia?
Acute myeloid leukaemia (rapidly progressing cancer of the myeloid cell line)
Acute lymphoblastic leukaemia (rapidly progressing cancer of the lymphoid cell line)
Chronic myeloid leukaemia (slowly progressing cancer of the myeloid cell line)
Chronic lymphocytic leukaemia (slowly progressing cancer of the lymphoid cell line)
Pathophysiology of leukaemia
A genetic mutation in one of the precursor cells in the bone marrow leads to excessive production of a single type of abnormal white blood cell.
The excessive production of a single type of cell can suppress the other cell lines, causing the underproduction of different cell types. This can result in pancytopenia
Who does AML tend to affect?
more common in older adults (65+)
slightly more common in men
What is acute myeloid leukaemia?
haematological malignancy caused by clonal expansion of myeloid blasts in the bone marrow
What is the pathophysiology of AML?
genetic abnormalities in haematopoietic precursor cells result in the accumulation of myeloid blasts unable to differentiate into mature neutrophils, RBCs or platelets.
This can lead to bone marrow failure (manifest as anaemia, neutropenia, and/or thrombocytopenia)
Risk factors for AML
Exposure to radiation, benzene, or alkylating agents
Chromosomal rearrangements such as t(15;17)(q22;q12)
Chromosomal abnormalities: Down syndrome
Age over 65
Inherited genetic conditions: Bloom’s syndrome
Myelodysplastic syndromes
Signs and symptoms of AML
Pallor
Petechiae
Fatigue
Loss of appetite + Weight loss
Fever/ infection
Dizziness
Palpitations
Dyspnoea
Bruising and mucosal bleeding: due to thrombocytopaenia
Pain and tenderness in the bones
Hepatosplenomegaly
Lymphadenopathy (enlarged lymph nodes)
What are the most common sites of infiltration in AML?
liver, spleen and gums
What would an FBC show in AML?
Anaemia, neutropenia, and/or thrombocytopenia
WBC may be elevated
What would be seen on a peripheral blood smear for AML?
Blast cells
presence of Auer rods
What is the diagnositc test for AML?
Bone marrow aspiration: ≥20% myeloblasts
What investigations should be done for AML and what would they show?
FBC: anaemia, neutropenia, and/or thrombocytopenia, WBC may be elevated despite neutropenia
Clotting screen: DIC
Peripheral blood smear: presence of Auer rods
Bone marrow aspiration: ≥20% myeloblasts
Lactate dehydrogenase
Differential diagnoses for AML
ALL
Biphenotypic leukaemia
MDS
Aplastic anaemia
Myelofibrosis (different blood film)
B12 deficiency
Management of AML
multi-agent, dose-intense chemotherapy
Complications of AML
Pancytopenia
Leukostasis
Tumour lysis syndrome
Neutropenia
Poor prognostic factors for AML
> 60 years
20% blasts after first course of chemo
cytogenetics: deletions of chromosome 5 or 7
What is acute lymphoblastic leukaemia?
a malignant clonal disease that develops when a lymphoid progenitor cell becomes genetically altered and undergoes uncontrolled proliferation
majority affect B cells but can also affect T
Who does ALL normally affect?
Can occur at any age but most common in children
Peak incidence ages 1-4
most common childhood malignancy
Risk factors for ALL
Children less than 5 years of age
Family history of ALL
history of malignancy
treatment with chemotherapy
exposure to radiation
smoking
folate metabolism polymorphisms
What factors can contribute to the development of ALL?
- Genetic
- Genetic disorders: Down, Klinefelter, Bloom
- Environmental: including radiation exposure and smoking
- Viral infections
- History of malignancy
- Treatment with chemotherapy
- Poor maternal diet
What are the chromosomal abnormalities for ALL?
- t(12;21) is the most common cytogenetic abnormality in children.
- In adults, the Philadelphia chromosome is the most common cytogenetic abnormality and describes the translocation t(9;22)
What does a blood film for ID anaemia show?
microcytic, hypochromic RBCs
variation in shape and size
When does anaemia of chronic disease occur?
in chronic inflammatory diseases, e.g. Crohn’s, SLE, RA