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Haematology > Anaemia > Flashcards

Anaemia Flashcards

1
Q

What is a normal reticulocyte count?

A

1-2%

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2
Q

What happens to the reticulocyte account in anaemia in a properly functioning marrow?

A

Increases to >3%
= Good marrow response

If <3% = poor marrow response

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3
Q

List causes of microcytic anaemia

A

Fe deficiency anaemia
Thalassemia (disorder of globin synthesis)
Anaemia of chronic disease (impaired iron metabolism)
Sideroblastic anaemia (disorder of haem synthesis)
Lead poisoning (disorder of haem synthesis)

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4
Q

Hb is made up of haem (… +…) + globin

A

Haem = iron + protoporphyrin

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5
Q

List causes of normocytic anaemia

A 
Blood loss
Haemolysis
Anaemia of chronic disease
Renal failure/anaemia
BM failure - infiltration, chemo/drug-induced
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6
Q

List causes of macrocytic anaemia

A 
B12 (megaloblastic)
Folate (megaloblastic)
ETOH (B12 deficiency, liver disease, BM suppression)
Multiple myeloma
MDS
Hypothyroidism
Liver disease
Drugs - MTX, azathioprine, cyclophosphamide, chemotherapy, allopurinol, erythromycin, PPI, OCP, hydroxyurea, trimethoprim
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7
Q

Where is iron absorbed?

A

Duodenum

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8
Q

Iron is consumed in two forms. What are they?

A

Haem (meat)

Non-haem (vegetables)

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9
Q

What happens to your platelets in iron deficiency?

A

Raised platelets

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10
Q

List causes if iron deficiency

A

Blood loss
Low iron intake (vegetarians)
Reduced absorption - IBD, coeliac, bariatric surgery, H.pylori
Increased demand - pregnancy, lactation, puberty
Paroxysmal nocturnal haemoglobinuria (rare)

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11
Q

List clinical features of Fe deficiency

A

Features of anaemia
Kilonychia (spoon-shaped nails)
Pica (chew on things classically ice)

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12
Q

How long to wait before checking response to IV iron?

A

6 weeks

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13
Q

In what diseases would you consider a higher iron target?

A

Renal failure

Heart failure

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14
Q

How does the MCV compare in thalassemia and iron deficiency?

A

MCV is often much longer in thalassemia

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15
Q 
What do you the following parameters reflect:
Serum iron
Transferrin/total iron binding capacity
Tf sat
Ferritin
A

Serum iron - this can fluctuate with food, time of day
Transferrin/total iron binding capacity - measure of transferrin molecules (made by liver) in the blood
Tf sat - % of transferring molecules that are bound to iron
Ferritin - iron stored in macrophages or liver

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16
Q

What is DMT1, haem carrier protein-1 (HCP-1) and ferroportin?

A

DMT 1 transports non-haem iron (Fe2+; vegetable) from gut lumen to enterocyte

HCP-1 transports haem iron (meat) from gut lumen to enterocyte

Ferroportin transports Fe2+ from enterocyte to blood

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17
Q

What’s hepcidin?

A

Expressed mostly in the liver (small amounts in muscle, intestine, lungs etc)

1) Binds to ferroportin and stops iron from going from enterocyte to circulation (traps iron within enterocyte)
2) Traps iron in macrophages
3) Suppresses EPO production

Goal is to prevent bacteria from accessing iron

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18
Q

What happens to hepcidin in these situations?
High iron =
Hypoxia =
Inflammation =
Erythropoiesis =
Chronic haemolytic anaemia or thalassemia =
Haemachromatosis =

A

High iron = high hepcidin
Hypoxia = low hepcidin (want more RBCs to be produced so need more iron)
Inflammation = high hepcidin (reduce amount of iron available to bacteria)
Erythropoiesis = low hepcidin
Chronic haemolytic anaemia or thalassemia –> Fe overload = low hepcidin (inappropriate –> worsens iron overload)
Haemachromatosis = low hepcidin (inappropriate)

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19
Q

How to differentiate between iron deficiency anaemia and anaemia of chronic disease?

A

Serum iron - both low
Transferrin/TIBC - high + low
Tf sat - both low
Serum ferritin - low + normal/high

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20
Q

What is sideroblastic anaemia?

A

Anaemia due to defective protoporphyrin synthesis

- Reduced protoporphyrin –> reduced haem –> reduced Hb –> microcytic anaemia

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21
Q

How do you get sideroblastic anaemia?

A

Congenital

Acquired - ETOH, lead poisoning, Vitamin B6 deficiency (isoniazid in TB)

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22
Q

What is your iron status like in sideroblastic anaemia?

A

Fe overloaded state
Because the problem is you don’t have enough protoporphyrin!

Iron + protoporphyrin = haem

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23
Q

Hb consists of 2 pairs of globin chains. Pair of alpha chains and pair of non-alpha chains (these are …)

A

Adult: beta chains
Baby: Gamma chains

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24
Q

What are the 2 types of thalassemia?

A

𝛼- and 𝛽-thalassemia

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25
Q 
What happens in 𝛼-thalassemia?
A) 1 gene deletion
B) 2 gene deletion
C) 3 gene deletion
D) 4 gene deletin
A

A) asymptomatic
B) mild anaemia with raised RBC count
C) severe anaemia; 𝛽 chains form tetramers (Hb) that damage RBCs
D) hydrops fetalis (lethal in utero); 𝛾 chains form tetramers (Hb Barts) that damage RBCs

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26
Q

𝛽-thalassemia

Two 𝛽 genes are present on chromosome 11; mutations result in absent (𝛽0) or diminished (𝛽+) production of the 𝛽-globin chain.

What happens in 𝛽-thalassemia minor?

A

𝛽/𝛽+
Mildest form of disease
Asymptomatic with raised RBC
Hb electrophoresis shows slightly decreased HbA and increased HbA2 (𝛼2𝛿2) and HbF (𝛼2𝛾2).

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27
Q

What are the normal types of Hb?

A

HbF (𝛼2𝛾2) - foetal
HbA (𝛼2𝛽2) - adult
HbA2 (𝛼2𝛿2) - small portion of adult Hb

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28
Q

𝛽-thalassemia

Two 𝛽 genes are present on chromosome 11; mutations result in absent (𝛽0) or diminished (𝛽+) production of the 𝛽-globin chain.

What are the complications of 𝛽-thalassemia major?

A

𝛽0/𝛽0
Most severe form of disease

1) Severe anaemia within a few months of life (HbF at birth is temporarily protective)
- Unpaired 𝛼 chains precipitate and damage RBC membrane, resulting in ineffective erythropoiesis and extravascular haemolysis (by spleen)

2) Massive erythroid hyperplasia/extramedullary haematopoiesis
3) Iron overload
4) Cholecystitis (increased RBC turnover –> increased unconjugated bilirubin)
5) Unusual VTEs (thrombophilia especially those post splenectomy)
6) High output heart failure, pulmonary hypertension

Above can also happen in thalassemia intermedia (wide spectrum from asymptomatic to almost transfusion dependent

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29
Q

What is massive erythroid hyperplasia in 𝛽-thalassemia major?

A

Expansion of haematopoiesis into the skull (reactive bone formation leads to ‘crewcut’ appearance on xray and facial bones (‘chipmunk facies’)

Extramedullary haematopoiesis with hepatosplenomegaly, paraspinal mass (can cause nerve compression and paraplegia/quadraplegia)

Risk of aplastic crisis with parvovirus B19 infection of erythroid precursors

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30
Q

Electrophoresis in 𝛽-thalassemia major?

A

Electrophoresis shows HbA2 and HbF with little or no HbA

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31
Q

In 𝛽-thalassemia, what do 𝛽0 and 𝛽+ mean?

A

𝛽0 absent production of beta chain

𝛽+ reduced production of beta chain

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32
Q

Explain how HbS is formed in sickle cell disease

A

A single amino acid change replaces normal glutamic acid (hydrophilic) with valine (hydrophobic)
= Abnormal 𝛽 chain of haemoglobin
= Results in HbS

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33
Q

How does HbS cause problems?

A

HbS polymerises when deoxygenated –> polymers aggregate into needle like structures –> distorts RBC shape –> difficulty manoeuvring through vasculature –> damage to RBC membrane

“Sickling” is reversible

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34
Q

What causes HbS to sickle or precipitates sickle cell crisis?

A 
Hypoxia
Hypo/hyperthermia
Altitude
Acidosis
Pregnancy
Fever
Sepsis

Cells sickle –> blocks vasculature –> causes inflammation

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35
Q

What protects HbS from sickling?

A

HbF
High HbF at birth protects HbS from sickling (presents only after 6 months of age). Taking hydroxyurea produces more HbF.

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36
Q

List complications of sickle cell disease

A

Almost every organ can be affected

  • Anaemia
  • Jaundice with unconjugated bilirubin –> bilirubin gallstones
  • Chipmunk facies, frontal bossing
  • Hepatosplenomegaly
  • Pain crisis from infarction
  • Infarction of organs including bone, spleen/shruken fibrotic spleen/autosplenectomy, MI/ACS, kidneys/renal papillary necrosis, lungs/acute chest syndrome, stroke, dactylitis
  • Infections (hyposplenism)
  • Leg ulcers
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37
Q

What are the consequences of autosplenectomy in sickle cell disease?

A

Infection with encapsulated organisms such as strep pneumoniae, haemophilus influenzae (most common cause of death in children)
Increased risk of salmonella typhi osteomyelitis (usually staph aureus in normal people)

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38
Q

How does acute chest syndrome present in sickle cell disease?

A
  • Chest pain, SOB, lung infiltrates
  • Often precipitated by pneumonia
  • Most common cause of death in adults
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39
Q

What’s the difference between sickle cell trait and sickle cell disease?

A

Trait: presence of one mutated and one normal 𝛽 chain, results in <50% HbS in RBCs

Disease: presence of 2 mutated 𝛽 chains, resulting in >90% HbS in RBCs

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40
Q

Do people with sickle cell trait have symptoms?

A

Generally asymptomatic
No anaemia
RBCs with <50% HbS do not sickle in vivo except in renal medulla (extreme hypoxia and hypertonicity of the medulla can cause sickling –> microinfarction –> microscopic haematuria –> inability to concentrate urine)

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41
Q

What do you expect to see on blood film in sickle cell disease?

A 
Target cells (dehydrated cells due to damaged RBC membranes)
Sickle cells

Not seen in sickle cell trait

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42
Q

What do you expect to see on electrophoresis in sickle cell disease/trait?

A

Disease - >90% HbS, 8% HbF, 2% HbA2 (no HbA)

Trait - 43% HbS, 55% HbA, 2% HbA2

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43
Q

Inheriting the thalassemia gene mutation is protective against …

A

Malaria

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44
Q

What is Haemoglobin E?

A

Structurally abnormal hb

Behaves like a 𝛽-thalassemia mutation

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45
Q

List some lab screening tests for thalassemia

A

FBC + blood flim

  • Microcytic, hypochromic anaemia
  • Target cells
  • Nucleated RBCs (when made in abnormal location such as liver, spleen, they escape too early and retain nucleus)

Iron studies - iron overload

Hb electrophoresis - shows HbA, HbF, little HbA2

Sickle solubility test

Genetic testing

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46
Q

What’s high performance liquid chromatography?

A

Similar to Hb electrophoresis
Can identify different Hb molecules
E.g. shows that the patient has elevated HbA2
However can’t tell which type of 𝛽-thalassemia (e.g. 𝛽+/𝛽0, 𝛽0/𝛽0), and is normal in alpha thalassemia carriers (need genetic testing)

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47
Q

Rx for 𝛽-thalassemia major (𝛽0/𝛽0)

A

1) Transfusion dependent
2) Iron chelation (for iron overload)
3) Consider splenectomy

48
Q

Complications of iron overload

A
  • Excessive melanin skin pigmentation (bronze diabetes)
  • Hypothyroidism
  • Hypoparathyroidism
  • Pulmonary hypertension and embolism
  • Cardiomyopathy (major cause of death)
  • Arrhythmias
  • Venous thrombosis
  • Haemosiderosis and cirrhosis of liver
  • Diabetes (beta cell destruction)
  • Delayed puberty
  • Osteoporosis
  • Testicular or ovarian failure
  • Splenomegaly
49
Q

How to assess iron overload? (transfusion dependent thalassemia)

A

1) Serum ferritin - useful for frequent monitoring

2) MRI to measure iron concentration in liver and heart
- Very high iron concentration correlates with liver fibrosis/liver function abnormalities, and heart failure

50
Q

What are some available iron chelation thearpies?

A

Desferrioxamine (DFO)
Deferiprone (DFP)
Deferasirox (DFX)

51
Q

Whats HbH disease?

A

HbH has extremely high O2 affinity –> doesn’t unload oxygen to tissue

Hence it is an ineffective carrier of oxygen

52
Q

Where is folate absorbed?

A

Jejunum

53
Q

Is it more common to be folate or B12 deficient?

A

Folate deficiency is more common as we have minimal body stores. Can develop within months.

B12 deficiency takes years to develop due to large stores B12 in the liver

54
Q

Where do we get folate from?

A

Vegetables and fruits

55
Q

Causes of folate deficiency

A

Poor diet (alcoholics, elderly)

Increased demand (pregnancy, haemolysis, chronic inflammatory state such as cancer)

Folate antagonist e.g. MTX, trimethoprim

B12 deficiency disrupts folate uptake into cells (but increases serum folate)

56
Q

How is vitamin B12 absorbed?

A

Dietary vitamin B12 is bound to animal-derived protein
Salivary amylase liberates vitamin B12, which is then bound to R-binder (salivary gland)
Carried to stomach
Pancreatic proteases in the duodenum detach vitamin B12 from R binder
Vitamin B12 binds intrinsic factor (gastric parietal cells) in the small bowel
Vitamin B12-intrinsic factor complex gets absorbed in the terminal ileum –> portal blood system

57
Q

Where is vitamin B12 absorbed?

A

Terminal Ileum

58
Q

Causes of Vitamin B12 deficiency

A

1) Pernicious anaemia (most common)
- Autoimmune destruction of gastric parietal cells –> intrinsic factor deficiency
- Intrinsic factor (IF) ab = very specific
- Parietal cell ab = very sensitive

2) Poor diet (rare)
- Vegans, alcoholics, underlying haemolytic anaemia

3) Crohn’s
Inflammation of ileum

4) Small bowel resection or gastrectomy
5) Pancreatic insufficiency
6) Infection - tropical sprue, tapeworm

59
Q

Clinical findings of Vitamin B12 deficiency

A

1) Glossitis, angular stomatitis

2) Subacute combined degeneration of the spinal cord
- Affects posterior (dorsal column tract) and lateral (corticospinal tract)
- Poor proprioception and vibration (symmetrical neuropathy LL > UL) and spastic paresis
- May be reversible

3) Neural tube defects (spina bifida)
4) Increased melanin/pigmentation

60
Q

Lab findings in vitamin B12 deficiency

A

Low serum B12

Film: Macrocytic anaemia, hypersegmented neutrophils, oval macrocytes (RBC), low reticulocytes, pancytopenia (if severe)

BM: megaloblastic change

Positive haemolysis screen

Holo-transcobalamin II - measures the amount of B12 bound to transcobalamin (available to tissues)

61
Q

Clinical findings of folate deficiency

A 
Diarrhoea, LOA, LOW
Weakness
Sore tongue
Headaches
Palpitations
Irritability
Infertility 
Infants with neural tube defects 
Signs of anaemia
62
Q

Lab findings in folate deficiency

A

Low serum folate (variable depending on recent intake)
Low red cell folate (>95% folate is in RBC; best assessment of long term stores; less variable)

Film: Macrocytic anaemia, hypersegmented neutrophils, oval macrocytes (RBC), low reticulocytes, pancytopenia (if severe)

BM: megaloblastic change

63
Q

How to reverse methotrexate toxicity?

A

Leucovorin (folinic acid)

To reverse folate deficiency caused by dehydro-folate-reductase inhibition caused by MTX

64
Q

Where are RBCs destroyed in extravascular haemolysis and intravascular haemolysis?

A

Extravascular: reticuloendothelial system (macrophages of the spleen, liver, lymph nodes)

Intravascular: within the blood vessels

65
Q

What’s in a haemolysis screen?

A 
Bilirubin
Haptoglobin
Reticulocyte count
LDH
Blood flim
Direct Coombs test - measures level of immunoglobulins stuck onto red cells; positive in autoimmune haemolysis

Do urinary haemosiderin if suspecting intravascular

66
Q

What 3 things indicate haemolysis?

A

Increased red cell breakdown or free Hb

Damaged red cells

Compensatory erythropoiesis

67
Q

In haemolysis, list evidence of red cell breakdown

A

Hyperbilirubinemia
Reduced haptoglobin

Intravascular haemolysis 
Raised plasma Hb
Haemoglobinuria
Urinary haemosiderin
Methaemalbuminaemia
68
Q

In haemolysis, list examples of damaged red cells

A

Spherocytosis (increased osmotic fragility)

Fragmented and contracted cells (TTP)

Sickled cells

69
Q

In haemolysis, list examples of compensatory erythropoiesis

A

Reticulocyte >3%

Erythroid hyperplasia of marrow

70
Q

What are spherocytes (in hereditary spherocytosis)?

A

Defect in cytoskeleton of RBC membrane
These RBCs are round instead of donut shaped
Less able to manoeuvre through splenic sinusoids and are consumed by splenic macrophages
Increased osmotic fragility (lyses in hypertonic saline)

71
Q

List clinical features of hereditary spherocytosis

A

Jaundice (RBCs –> unconjugated bilirubin)
Gallstones
Splenomegaly
Leg ulcers
Haemolytic “crisis” (often in the presence of infection)
Aplastic crisis (parvovirus B19 infection)

72
Q

Where does the haemolysis occur in hereditary spherocytosis?

A

Extravascular (spleen)

73
Q

Rx: hereditary spherocytosis

A

Splenectomy (problem is not with the spherocytes but with the destruction of the spherocyte by the spleen)

74
Q

How is hereditary spherocytosis diagnosed?

A

Blood film: spherocytes
Negative DAT/direct coombs test
Flow cytometry

75
Q

How to manage chronic sickle cell disease?

A
  • Transfusions or RBC exchange (replace sickle cells with normal RBCs; target HbS <30%)
  • Hydroxyurea - boost HbF which is protective against sickle cell
  • Immunisation (from hyposplenism)
  • Folic acid (need it to make RBCs)
  • Consider BM transplant

Novel therapy - crizanlizumab (prevent pain crisis), gene therapy

76
Q

How to manage acute sickle cell crisis?

A
  • Aggressive hydration
  • Analgesia
  • Treat infection
  • If severe may require red cell exchange
77
Q

When is hydroxyurea indicated in sickle cell disease?

A

Adults with ≥3 pain crisis/year
Adults with sickle cell-associated pain that interferes with ADLs/QOL
History of recurrent or severe ACS
All Children >9 months old

78
Q

Which antibodies are involved in immune haemolytic anaemia?

A

IgG - extravascular haemolysis

IgM - intravascular haemolysis

79
Q

How to diagnose immune haemolytic anaemia?

A

Coombs (DAT) test - can be direct or indirect
- Positive DAT does not = haemolysis

Evidence of haemolysis

80
Q

What’s the difference between direct and indirect Coombs test?

A

Direct looks at the presence of ab or complement on RBCs

Indirect looks at the presence of ab in the serum

81
Q

What are the 2 main types/syndromes of autoimmune haemolytic anaemia?

A

Warm AIHA >85%

Cold agglutinin haemolysis <15%

82
Q

List some secondary causes of autoimmune haemolytic anaemia

A 
Lymphoproliferative disorders
Other malignancy
Infection
CT disease e.g. SLE
Drug induced or associated
83
Q

What is warm autoimmune haemolytic anaemia?

A

Warm temperature –> IgG binds RBCs –> RBCs are consumed by splenic macrophages –> spherocytes (membranes are removed bit by bit)

Extravascular haemolysis

84
Q

What is warm autoimmune haemolytic anaemia associated with?

A

SLE (most common cause)
CLL
Drugs classically penicillin and cephalosporin
Viruses

85
Q

How to treat warm autoimmune haemolytic anaemia?

A

Transfusion if Hb <70
Steroids (pred 1mg/kg)
DVT prophylaxis

2nd line
IVIG (spleen eats this instead of RBCs = buys time)
Rituximab (takes time to work so can use IVIG in the mean time; probably consider this prior to splenectomy)
Splenectomy (removes source of ab)

Refractory
Cyclosporine
High dose cyclophophamide
Mycophenolate mofetil
Danazol
86
Q

What is cold agglutinin/autoimmune haemolytic anaemia?

A

Cold temperature –> IgM binds RBCs –> binds complement –> activates complement –> intravascular haemolysis

Intravascular

87
Q

What is cold agglutinin/autoimmune haemolytic anaemia associated with?

A

Mycoplasma pneumoniae
EBV/CMV
Lymphoma
Idiopathic

88
Q

How to treat cold agglutinin/autoimmune haemolytic anaemia?

A

Often not significant enough to treat
Keep warm
Rituximab
Steroids (if mixed cold/warm antibodies)

89
Q

What happens to RBCs in G6PD deficiency?

A

G6PD deficiency makes RBCs susceptible to oxidative stress –> oxidative stress –> intravascular haemolysis

90
Q

How do you get G6PD deficiency?

A

Inherited

X linked recessive disorder

91
Q

What precipitates haemolysis in G6PD deficiency?

A

Oxidative stress

Causes include infections, drugs (e.g. sulphur drugs, dapsone) and fava beans

92
Q

How does G6PD deficiency present?

A

Haemoglobinuria
Back pain (Hb is nephrotoxic)
Hours after exposure to oxidative stress

93
Q

What do you see on blood flim in G6PD deficiency after an episode of oxidative haemolysis?

A

Bite cells

94
Q

What are heinz bodies and bite cells?

A

In G6PD deficiency

Oxidative stress precipitates clumps of damaged Hb within the RBCs (Heinz bodies). These Heinz bodies are removed by splenic macrophages, resulting in bite cells

They are evidence of oxidative injury

95
Q

What happens to the small vessels in microangiopathic haemolytic anaemia (MAHA)?

A

Get platelet microthrombi formation (consume platelets) –> RBCs are “sheared” as they pass through the microthrombi –> haemolytic anaemia

96
Q

What are the disorders associated with microangiopathic haemolytic anaemia (MAHA)?

Hint: 2 groups

A

2 groups

Group 1 - platelet microthrombi –> sheer stress

1) TTP
- large uncleaved VWF –> Platelet microthrombi
2) HUS
- Drugs/infection cause endothelial damage –> platelet microthrombi
3) DIC
4) HELLP/pre-eclampsia

Group 2 - mechanical haemolysis

5) Prosthetic heart valves
6) Severe aortic stenosis (calcified)

97
Q

What are the clinical findings of TTP/HUS?

A

MEDICAL EMERGENCY

Thrombocytopenia
AKI (microthrombi formation in the renal vessels)
Neurological abnormalities (microthrombi formation in the vessels of the CNS)
Fever
Microangiopathic haemolytic anaemia
Bleeding/bruising

98
Q

What abnormal lab findings do you expect in microangiopathic haemolytic anaemia (MAHA)?
Think FBC, blood film, BM

A

Low platelets
Low Hb
Blood film: schistocytes (red cell fragments), polychromasia (multicoloured RBCs; suggests RBCs being released prematurely from BM)
Evidence of haemolysis
BM: lots of megakaryocytes (to try and make more platelets)

99
Q

Rx microangiopathic haemolytic anaemia (MAHA)

A

Plasmapharesis (to remove autoantibodies)

Corticosteroids

100
Q

Pathogenesis of TTP

A

Large uncleaved VWF molecules (should normally be cleaved by ADAMTS13 which are being attacked by autoantibodies) –> catch platelets –> platelet microthrombi –> shear RBCs –> haemolysis –> end organ damage

101
Q

How to diagnose TTP?

A

Clinical and ADAMTS 13 <10%

Exclude STEC infection (shiga toxin producing ecoli)

102
Q

How to manage TTP?

A 
Medical emergency
Apharesis (remove whole blood from the patient, separate the blood into individual component so that one particular component can be removed)
FFP
Steroids
Rituximab 
(Caplacizumab - not available in Aust)

Assess with LDH and platelet count

103
Q

What are the disorders associated with TTP/HUS/MAHA?

A 
Idiopathic
Familial
Complement induced MAHA - Rx eculizumab
Infection (ecoli, HIV) - diarrhoea associated HUS
SLE
Pregnancy/post-partum
Chemotherapy
Drugs - quinine, cyclosporin 
BM transplant
104
Q

How does paroxysmal nocturnal haemoglobinuria result in haemolytic anaemia and haemoglobinuria?

A

GPI anchors decay accelerating factor (DAF) to RBCs
Absent GPI –> absent DAF –> RBCs susceptible to complement damage –> intravascular haemolysis of RBC, WBC, platelets –> haemaglobinemia + haemaglobinuria + haemosiderinuria (days later)

105
Q

What time of the day does paroxysmal nocturnal haemoglobinuria occur?

A

During sleep –> shallow breathing –> mild respiratory acidosis –> activates complement –> haemolysis

106
Q

What are the complications of paroxysmal nocturnal haemoglobinuria?

A

1) Venous thrombosis in unusual places
Destroyed platelets –> release cytoplasmic content –> thrombosis
Main cause of death

2) Iron deficiency anaemia (due to chronic loss of Hb in the urine)

3) Acute myeloid leukaemia - 10%
- Problem in the myeloid stem cell which results in absent GPI in the first place

107
Q

How to diagnose paroxysmal nocturnal haemoglobinuria?

A

Flow cytometry to detect lack of CD59 (DAF) on blood cells and CD16 on neutrophils

108
Q

Rx for paroxysmal nocturnal haemoglobinuria

A

Eculizumab

- Ab against complement

109
Q

What disease do you see spur cells/acanthrocytes (RBCs with spike like projections)?

A

End stage liver disease

110
Q

How do you get anaemia in ESKD?

A

Lack of EPO
Iron sequestration in anaemia of chronic disease
Iron, B12, folate deficiency

111
Q

What’s the Hb target in GI bleed?

A

80
But transfuse anyway if haemodynamically unstable
Aim 80-100 in IHD

112
Q

What’s the Hb target in variceal bleed?

A

70
But transfuse anyway if haemodynamically unstable
Aim 80-100 in IHD

113
Q 
List the antigen on RBC, ab in serum and compatible blood for each of the following:
A) Blood group A
B) Blood group B
C) Blood group AB
D) Blood group O
A

A)
A
B, AB
A, O

B)
B,
A, AB
B, O

C)
A, B
Nil
AB, A, B, O

D)
Nil
A, B
O only

114
Q

Which blood is the universal plasma (contains no antibodies)?

A

AB

Not O

115
Q

What is the ratio of plasma to red cells to platelets used in massive transfusion?

A

Start with 1:1:1
i.e. RCs 4 units: FFP 4 units: plat one pool

Next pack add in cyoprecipitate 8-10 units
Check coags regularly to look for trends if not using TEG/ROTEM

116
Q

How is recombinant factor VIIa used in massive transfusion?

A

Enhances thrombin generation on already activated platelets
Turns off bleeding in 15 minutes!
Very $$$$, not used frequently
Effective, well tolerated

117
Q

List examples of adverse transfusion reactions

A

Allergy
Febrile non-haemolytic transfusion reaction
Fluid overload
TRALI
Delayed haemolytic transfusion reaction
Infection - hepatitis, HIV, bacterial infection
ABO incompatibility

Haematology (7 decks)

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