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Foundations of Clinical Science > Anaemia and Haemoglobinopathies > Flashcards

Anaemia and Haemoglobinopathies Flashcards

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1
Q

What is a full blood count?

A

Assess number and size of cells found in blood eg RBC/WBC/platelets (baseline test)

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2
Q

What is haematopoeisis and where does it occur?

A

The production of all types of blood cells which occurs in the bone marrow in long bones. Maturation of immature bood cells occurs in bone marrow and mature cells then circulate within peripheral blood

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3
Q

What is EDTA?

A

Collating agent and it stops the blood from clotting so you are able to analyse cells properly. Used in FBC

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4
Q

What does FBC tell us?

A

Hb: conc of Haemoglobin (g/L)
Haematocrit: % of blood volume as RBC
MCV (mean cell vol): Average size of RBC
MCH: Average haemoglobin content of RBC
MCHC: calculated measure of haemoglobin concentration in given red blood cells
RDW (red cell distribution width): Range of deviation around RBC size, tells you if theres a great difference between shapes and sizes of cells

Can also request:
Reticulocyte count (immature RBC)
Blood film: microscopy

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5
Q

What are the features of red blood cells in a blood film regarding:
a) Size
b) Shape
c) Colour
d) Inclusions?

A

Size : big, small, normal

Shape : fragments, tear drop, spiculated, ovalocyte, spherocyte, eliptocyte

Colour: pale (hypochromic), normal, polychromasia

Inclusions: howell-jolly bodies, nuclear reminants, malarial parasites, basophilic stippling

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6
Q

What are some additional tests that can be done besides a FBC?

A

Bone Marrow Aspirate & Trephine
Haematinic levels: B12 & folate
Iron studies: ferritin, serum Fe, TIBC
High Performance Liquid Chromatography (for Hb variants eg in someone with anaemia)

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7
Q

What is the structure of Haemoglobin?

A

4 polypeptide chains, 2 alpha and 2 beta globin chains each with own haem group

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8
Q

What is the difference between Aspirate and Trephine?

A

Aspiration: thin needle used to remove fluid from bone marrow (aspirate) pelvic bone but sometimes chest

Trephine: bone marrow biopsy removes pieece of bone from bone marrow

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9
Q

What is present in normal adult blood?

A

HbA (a2b2)
Small amounts of HbF and HbA2

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10
Q

Where do the genes for globin chains occur?

A

In 2 clusters on chromosomes 11 and 16

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11
Q

Define haemoglobinopathies

A

Genetic conditions from either abnormal Hb variants eg HbA (sickle cell) or reduced rate of synthesis of alpha or beta chains (thalassemia)

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12
Q

Why do patients with sickle cell disease not exhibit symptoms from birth?

A

After the first three months of life, your body stops producing foetal haemoglobin and produces adult haemoglobin, in which the point mutation will be present

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13
Q

What is anaemia?

A

Hb below normal ranges
Classified as microcytic, normacytic and macrocytic

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14
Q

What are causes of microcytic anaemia?

A

Iron deficiency
Thalassemia
Anaemia of chronic disease

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15
Q

What are causes of normocytic anaemia?

A

Anaemia chronic disease
Aplasia
Chronic renal failure

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16
Q

What are causes of macrocytic anaemia?

A

B12 deficiency
Folate deficiency

Myelodysplasia
Reticulocytosis
Drug induced
Liver disease
Myxoedema

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17
Q

Why is a reticulocyte count important in investigations?

A

Clue into causes of anaemia like failure of RBC production or increased losses

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18
Q

What are the causes of failure of production in anaemia?

A

B12, folate deficiency, iron deficiency, erythropoeitin deficiency in CKD, bone marrow failure (eg aplastic anaemia)

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19
Q

What are the causes of failure of appropiate utilisation in anaemia?

A

anaemia of chronic disease

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20
Q

What are the causes of increased destruction in anaemia?

A

Blood loss, haemolysis, (autoimmune, sickle, hereditary spherocytosis, TTP) reticulocytosis

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21
Q

What is the length of life cycle of a red blood cell in sickle cell?

A

20 days (120 normal)

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22
Q

What would you see in the blood film of a patient with microcytic anaemia?

A

The blood film of a patient with iron deficiency anaemia showing anisocytosis, poikilocytosis (including elliptocytes), hypochromia and microcytosis.

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23
Q

How is iron transported in blood?

A

Iron (comes from diet) transported from enterocytes then either into plasma or stored as ferritin

Once attached to transferrin it is transported and binds to transferrin receptors on RBC precursors

(so low iron = low ferritin bc stores being used up)

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24
Q

What will you see happen to ferritin and transferrin in iron deficiency?

A

A state of iron deficiency will see reduced ferritin stores and then increased transferrin

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25
Q

What is observed in iron studies?

A

Serum Fe
Hugely variable during the day

Ferritin
Primary storage protein & providing reserve, Water soluble (if low = iron deficient, BUT can go up if infection so need other studies)

Transferrin Saturation
Ratio of serum iron and total iron binding capacity – revealing %age of transferrin binding sites that have been occupied by iron (if low = iron deficient)

TIBC (Total Iron Binding Capacity)
Measurement of the capacity of transferrin to bind iron

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26
Q

What are some causes of iron deficiency?

A

poor diet
malabsorption
increased physiological needs

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27
Q

What could happen if someone loses too much iron?

A

Blood loss
menstruation, GI tract loss, paraistes

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28
Q

Why would it still be anaemia if someone is iron deficient with low Hb, but a normal reticulocyte count?

A

Because Hb is low, would assume reticulocyte production would double (go to higher end of normal range to compensate) so if it remains in lower end of normal range, patient cannot keep up and not making enough RBCs FAILURE OF PRODUCTION

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29
Q

What happens to reticulocyte count in SCD?

A

RETICULOCYTOSIS
Higher than normal- suggests increased haemolysis, could become a sickle cell crisis

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30
Q

What kind of neutrophil would you see in macrocytic anaemia?

A

Hypersegmented or right shifted, having many lobes eg around 8 instead of 4-5

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31
Q

What happens to reticulocyte count in macrocytic anaemia?

A

Low numbers, failure of production

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32
Q

What effect does alcohol have in regards to macrocytic anaemia?

A

Lowers b12 and folate levels, reduces utilisation of folate and have toxic effect on bone marrow

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33
Q

Where does folate come from and where is it absorbed?

A

Folate comes from most foods with 60-90% lost in cooking. It is absorbed in the Jejunum and the body has enough stores usually for 3-5 months

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34
Q

Why is B12 deficiency a problem?

A

B12: Essential co-factor for methylation in DNA and cell metabolism

Intracellular conversion to 2 active coenzymes necessary for the homeostasis of methylmalonic acid (MMA) and homocysteine

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35
Q

Why would a patient with a gastrectomy be B12 deficient (pernicious anaemia)?

A

They cant absorb it because the site of instrinsic factor secretion is in the stomach, which is needed fot B12 to be absorbed, which is removed in a gastrectomy (no intrinsic factor = no B12 absorption = B12 supplements wont help)

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36
Q

What is pernicious anaemia?

A

Autoimmune disorder
Gastric Parietal cell antibodies
IF antibodies

Lack of IF
Lack of B12 absorption

Pernicious anemia occurs when your body can’t absorb enough vitamin B12 to function properly.

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37
Q

If someone is exposed to lots of nitric oxide what type of anaemia are they likely to develop?

A

Macrocytic anaemia due to B12 deficiency (NO - problems absorbing B12)

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38
Q

What is the structural difference between thalassaemia and sickle cell?

A

SCD: haemolysis (abnormal Hb structure)
Thalassaemia: disorder of globin chain synthesis

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39
Q

What happens to globin chains in thalassaemia?

A

Reduction in globin chain production:

Alpha thalassaemia: usually due to large deletions in alpha globin complex
Beta thalassaemia: usually due to point mutations in beta gene

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40
Q

What is the structure of Hb globin chains?

A

4 alpha genes: 2 on each chr 16
2 beta genes: 1 on each chr 11

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41
Q

What are the different severities of alpha thalassaemia?

A

Severity depends on number deleted genes

  1. α_/αα = Asymptomatic
  2. _ /αα and α/α_ = alpha thal trait (microcytic anaemia)
  3. α_/_ _ HbH disease (anaemia and haemolysis)
  4. –/– Hydrops Fetalis (No alpha chain production)
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42
Q

Why is beta thalassaemia not diagnosed at birth?

A

Beta chains not in foetal Hb so problems in beta chain only apparent once switching from foetal Hb to adult Hb in first 3 months of life

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43
Q

What are the different severities of beta thalassaemia?

A

TWO TYPES:
β0: absent globin production
β+: reduced production

B THAL TRAIT = abnormality in 1 inherited gene (Microcytic anaemia, high HbA2)

B THAL INTERMEDIA OR B THAL MAJOR (BTM) = Abnormality in both genes
Transfusion requirements and varying severity

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44
Q

How do we define beta thal patients?

A

Whether or not they are transfusion dependant or not (TDT)

TDT: usually beta zero, excess alpha chains and ineffective erythropoeisis and severe anaemia
Transfudion dependant life long: blood they get has too much iron leading to iron overload - liver and cardiac loading and failure

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45
Q

What are the different types of sickle cell?

A

Inherited chronic haemolytic anaemia due to formation fo abnormal Hb (sickling and unsickling)
Most common form = HbSS
Other sickle disorders are compound heterozygotes: HbSC, HbSD, HbSG, HbSBthal

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46
Q

What is an occlusive crisis?

A

In SCD, RBCs not as mallebale and increased viscosity because they don’t flow well and get stuck, causing vaso-occlusion of vessels so no O2 delivery = pain due to ischaemia

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47
Q

What are the triggers for an occlusive crisis?

A

Hypoxia
Dehydration
Fever
Acidosis

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48
Q

What is needed to diagnose SCD?

A

HAEMOLYTIC ANAEMIA
Low Hb
High reticulocyte count
High LDH and bilirubin

BLOOD FILM
sickle cells
polychromasia
target cells

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49
Q

What is the sickle solubility test?

A

Confirms diagnosis of SCD alongside blood film

Functional test
Lysed RBC released Hb
Presence of phosphate buffer
HbS insoluble and turbid solution
Will be positive for HbSS and HbAS

Useful for OOH, primary screening

50
Q

What is HPLC?

A

HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

Separation technique
Under high pressure components will separate along a chromatographic column

Retention time: is the characteristic time taken for the haemoglobin species to elute from the column, and is printed above the peak on the chromatogram elution profile. The amount of each haemoglobin fraction present in percentage terms is represented by the area under the curve.

51
Q

What emergency events can occur in SCD?

A

Acute Anaemia (Haemolysis, sequestration, Parvo B19 aplastic crisis)

Acute Painful Crises
Acute Chest Syndromes (Hypoxaemia, chest pain, fever, infiltration)

Stroke (Ischaemia or Haemorrhage)
Priapism
Abdominal/ Mesenteric crises
AKI / Papillary Necrosis
Overwhelming infection (Hyposplenism, osteomyellitis (salmonella))

52
Q

What chronic problems do we see in SCD?

A

Chronic Haemolysis and anaemia
Pulmonary Hypertension
Nephropathy (Proteinuria
)Retinopathy
AVN
Chronic Pain
Iron Overload

(Memory, cognition, headaches, mood disorderspublic health and social needs)

53
Q

How do we manage an emergency in SCD vs long term issues?

A

EMERGENCIES:
pain relief
oxygen
antibiotics
blood transfusions

LONG TERM:
clinic follow up AT LEAST ONCE A YEAR
echocardiographs
hip examinations
retinal screening
urinalysis: protein
BP monitoring
pain relief
HYDROXYCARBAMIDE (acts on bone marrow and increases FHb and reduces HbS, reduces sickling)
EXCHANGE BLOOD TRANSFUSIONS

54
Q

Which lineage goes on to form RBCs?

A

Myeloid stem cells

55
Q

What is haematopoiesis and where does it occur?

A

The differentiation processes that leads to the formation of all blood cells from haematopoietic stem cells.

At birth in marrow of almost every bone

In adults, in central skeleton and proximal ends of long bones

56
Q

What is erythropoiesis?

A

Development of RBCs, mature from multipotent stem cell to reticulocyte to erythrocyte

57
Q

How are RBCs removed from circulation?

A

By macrophages in spleen, liver or bone marrow

58
Q

What are reticulocytes and what happens to them in circulation?

A

Reticulocytes: immature RBCs, no nucleus but contains RNA and some organelles

Develop into mature RBC within 1-2 days after release into circulation. Loss of RNA.

Reticulocyte count: can be used to represent marrow production of new RBCs. Useful
measure of erythropoiesis.

59
Q

What is EPO?

A

Erythtropoietin, drives proliferation and maturation of RBC precusors
Mainly secreted in kidney by tubular and interstitial cells that sense hypoxia

60
Q

Describe the structure and different types of haemoglobin

A

Cytosol of RBC contains Hb – synthesised before loss of nucleus
Each RBC contains ~280 million Hb molecules.
Hb Structure: Tetramer - 4 polypeptide globin chains
Each globin subunit contains a haem group.
Haem group: porphyrin ring + ferrous (Fe2+) atom
Fe2+ can bind reversibly to one oxygen molecule.
HbA -most common type of Hb in adult.
HbF is most dominant Hb 3-9months post conception
From 9 months post conception Y chain synthesis progressively reduces to a trace. HbF is replaced by adult Hb
By 1 year old – adult Hb ( a2, b2) is established

61
Q

Where is the spleen located?

A

Left hypochondriac region

62
Q

What are the two types of tissue in the spleen?

A

White pulp: lymphatic tissue (mostly lymphocytes and macrophages) arranged around
the branches of splenic artery - central arteries

Red pulp: blood filled venous sinuses and cords of splenic tissue called splenic cords (veins closely associated with red pulp)

63
Q

What are splenic cords?

A

consist of RBCs, macrophages , lymphocytes, plasma cells and granulocytes.

64
Q

What is the function of red pulp?

A

Removal of ruptured, worn out or defective blood cells and platelets by macrophages
Storage of platelets - up to 1/3rd of body’s supply
Production of blood cells (haemopoiesis ) during foetal life

65
Q

What is the function of white pulp?

A

B cells and T cells carry out immune functions, similar to lymph nodes
Opsonisation of encapsulated bacteria
Spleen macrophages destroy blood borne pathogens by phagocytosis

66
Q

Where does blood from the splenic artery enter?

A

Central arteries of white pulp

67
Q

What does FISH stand for regarding spleen function?

A

F- Filtration of encapsulated organism and
blood cells
I- Immunological function
S-Storage of blood
H- Haematopoeisis – in foetus to neonate

68
Q

What organ is important for opsonisation of encapsulated bacteria?

A

Spleen

69
Q

What is whole blood composed of?

A

Plasma and formed elements

70
Q

What is a useful measure of erythropoiesis?

A

Reticulocyte count

71
Q

Adult Hb is normally composed of…

A

97% HbA
2% HbA2
less than 1% HbF

72
Q

What is the
a) definition
b) signs
c) symptoms

of anaemia?

A

a) Low haemoglobin concentration:
men:<135 g/L , women: <115g/L

b) Pallor
• Tachycardia
• Systolic Flow murmur
• Cardiac Failure
• Specific
• Koilonychia: Spoon shaped nails - IDA
• Jaundice - Haemolytic anaemia
• Leg ulcers - SCA, Haemolytic anaemia
• Bone deformities - Thalassemia major

c) asymptomatic or specific:
fatigue
dyspnoea
palpitations
faintness
headache

73
Q

What is the
a) genetic mutation
b) risk factors for polymerisation
c) consequences

of sickle cell anaemia?

A

a) Point mutation (adenine → thymine) in Hb-β gene (ch-11)
• Hence, amino acid change (glutamic acid → valine)
• This alters the properties of the β-chain where the AA R-group changes:
hydrophilic (Glu) → hydrophobic (Val)
• Under hypoxia the R-group changes shape exposing a ‘pocket’ where all
the Hb molecules join up in a stiff line (polymerisation)
• This alters the RBC structure → sickle-shape

b) • Hypoxia - increases deoxygenated HbS
○ e.g. tissues with ↓O2, intense exercise, high altitudes
• Acidosis - decreases Hb affinity for O2
• Dehydration - increases concentration of HbS
• Infection/fever
•Cold temperature

c) •Reduces RBC life span (120 days to 30 days) → premature destruction and
high turnover
•Sequester in liver and spleen
•Occlude small vessels → vaso-occlusive crisis

74
Q

What are the clinical features of SCA?

A

Chronic pain
Anaemia (haemolytic)
○ Lethargy
○ Pallor
○ Weakness
○ Jaundice - from high levels of bilirubin
due to excessive RBC breakdown

Splenomegaly
Recurrent infections
Priapism (serious painful erections)
Delayed puberty and growth restriction
Periodic ‘attacks’ AKA sickle-cell crises

N.B. some patients remain asymptomatic until adulthood

75
Q

What is a vaso-occlusive crisis?

A

• In peripheral vessels this causes extreme agonising pain
• In other areas: vision loss, strokes, bowel ischaemia, renal papillary
necrosis, congestive heart failure, cholelithiasis, ACS
• Risk factors: cold, smoking, pregnancy, dehydration, stress, exercise

76
Q

What is acute chest syndrome?

A

• Vaso-occlusive crisis in lungs
• Causes chest pain, dyspnoea, fever
• Leading cause of death

77
Q

What is sequestration?

A

Trapped RBC in spleen
• Acute: acute splenomegaly, acute drop in Hb, haemodynamic instability
• Chronic: fibrosis and autosplenectomy ➝ increased infections

78
Q

What is an aplastic crisis?

A

• Transient cessation of haematopoiesis associated with parvovirus B19
• Presents similarly to heart failure

79
Q

What common infections can badly affect sickle cell patients?

A

Encapsulated organisms especially

Osteomyelitis
Malaria
Pneumonia
Salmonella
Parvovirus B19
Meningitis

80
Q

What investigations are done for sickle cell anaemia?

A
  1. Assess parental carrier status (if both parents carriers 25% risk of SCA in child)
  2. Offer antenatal diagnosis (Chorionic villus sampling, amniocentesis, non-invasive prenatal testing)
  3. Provide neonatal screening (heel prick test)
  4. Obtain bloods (FBC: Hb of 60-80g/l is anaemic, peripheral smear to see if reticulocyte is increased by 10-20% and sickled RBCs)
  5. Sickle solubility test (Normal Hb is negative, HbS is positive, precipitates and turbid)
  6. Hb electrophoresis (seperates different types of Hb eg HbSS and HbAS)
    HPLC used for older screening to confirm diagnosis
81
Q

How do we manage SCA via patient education and general care?

A
  1. Patient education
    ● Increase fluid intake
    ● Avoid triggers (e.g. excessive
    exercise
  2. General care
    ● Follow up regularly by secondary
    care
    ● Folate supplementation - high folate
    turnover due to haemolysis
    ● Immunisations - flu, HepB, PPV
    ● Antibiotic/malaria prophylaxis
82
Q

How do we manage a vaso-occlusive crises?

A

Preventing vaso-occlusive crises
● Top up transfusions
● Hydroxycarbamide/hydroxyurea -
increases HbF ➝ reduces sickling

83
Q

How do we manage acute complications in SCA?

A

Managing acute complications
● IV fluids, transfusions, O2,
● Analgesia (pain management)
○WHO pain ladder
○Usually opiates if in A&E - must
be given <30 mins and
reassessed every 30 mins

84
Q

How do we manage chronic complications in SCA?

A

Iron chelators - reduce excess iron
in blood

85
Q

Define thalassaemia

A

Thalassaemia: Inherited globin gene abnormalities
that result in underproduction or absence of either βglobin or α-globin chain.

• Classified according to which chain of globin molecule
is affected ( α or β):
• α genes – two genes, each on chromosome 16
• β genes – one gene, each on chromosome 11

86
Q

Where is beta thalassaemia prevalent?

A

Mediterranean, Middle East, South and Southeast Asia and Southern China

87
Q

Where is alpha thalassaemia prevalent?

A

Southeast Asia, Africa and Southern China

88
Q

What is the management for beta thalassaemia?

A

• 4-6 weekly red cell transfusion – to keep Hb > 10g/dL –
to supress bone marrow hypertrophy and iron absorption
• Iron chelation
• Splenectomy – may be indicated if hypersplenism.
Predisposes to life-threatening infections.
• Allogenic bone marrow transplantation
• Counselling and antenatal diagnosis made available

89
Q

What are the differences between beta thalassaemia intermedia and minor?

A

Beta Thalassaemia Intermedia:
• Less severe.
• Bone deformity and hepatosplenomegaly may occur.
• Haemoglobin maintained without transfusion.
• Blood film – similar to thalassaemia major.
• Iron overload – may occur. Increased iron absorption

Beta Thalassaemia Minor:
• Heterozygous state ( normal b-globin gene plus either a
b0 or b+ gene.
• Affected individuals are asymptomatic
• Carrier for thalassaemia major- reproductive advice and
antenatal diagnosis and foetal selection if partner is also
carrier.
• FBC: low Hb, low MCV. (Mimics iron deficiency)
• Hb electrophoresis: increased HbA2
• Iron status – normal

90
Q

What is curative treatment for SCA?

A

Haemopoietic stem cell transplants
(SCT)

91
Q

What are the purines and pyramidines?

A

PURINES: Adenine and Guanine (2 rings)
PYRAMIDINES: Cytosine and Thymine (1 ring)

92
Q

What bonds bind purines and pyramidines together?

A

Hydrogen bonds

93
Q

What is the central dogma?

A

DNA (replication) –> transcription –> RNA –> translation –> protein (‘phenotype’)

DNA to RNA in nucleus
RNA to protein in cytoplasm

94
Q

Can DNA be transported out the nucleus?

A

No, therefore transcribed to RNA as it can be transported out

95
Q

What is the structure of a gene?

A

Exons (coding)
Introns (non coding)
5’ end to 3’ end (prime)

96
Q

What are exons?

A

Code for amino acids except for Untranslated Regions (5’ UTR and 3’ UTR)

97
Q

What are UTRs?

A

Contain regulatory elements that are important for control of protein synthesis (don’t code for amino acids)

98
Q

What are introns?

A

Non coding section of gene between exons, if a gene has 2 exons it needs an intron inbetween

99
Q

What is the promotor region?

A

5’ end (upstream) of gene and contains important regulatory elements for transcription

100
Q

What is transcription?

A

Going from double stranded DNA to single stranded RNA, transcript has same base sequence as gene

101
Q

What base replaces thymine in RNA?

A

Uracil

102
Q

What are the types of RNA?

A

mRNA = messenger RNA – carries genetic information from nucleus to cytoplasm

rRNA = ribosomal RNA – located in cytoplasm; important in directing translation

tRNA = transfer RNA – located in cytoplasm; transfers amino acids to ribosome to generate protein

103
Q

What are post transcription modifications?

A

Capping, polydenylation and splicing = mature mRNA

104
Q

What does mRNA contain?

A

mRNA contains cap, 5’UTR, exons, 3’UTR, polyA tail

105
Q

What is translated?

A

Only RNA from coding exons

106
Q

What is the triplet code?

A

RNA “read” in threes = codons
64 possible combinations of 4 bases
Codon →specific amino acid
20 amino acids

Degenerate = >1 codon can code for same amino acid

107
Q

What are the types of mutation?

A

Substitution (point mutation)
Deletion
Insertion

108
Q

Where are mutations found?

A

Coding and non-coding DNA like promotors/introns

109
Q

What is a silent/synonymous base substitution?

A

Nucleotide change without amino acid change

110
Q

What is the difference between a missense and nonsense mutation?

A

Missense: single nucleotide change = incorrect amino acid = possible malfunctioning protein

Nonsense: single nucleotide change = amino acid for stop codon = shortening of protein

111
Q

What happens in an insertion or deletion?

A

If number of bases inserted divisible by 3 = IN FRAME
eg adds in one codon, other codons unaffected

If not = FRAMESHIFT (more likely to be pathogenic)
shifts all codons over by one base

Same for deletion, 3 bases deleted (in frame) or one base deleted causing frameshift

112
Q

What is the difference in cell wall structure between gram positive and negative bacteria?

A

Gram positives (purple) – large peptidoglycan layer
(easier to treat due to porous wall)

Gram negatives (pink) – thin peptidoglycan layer

113
Q

What colour does gram positive bacteria stain in iodine?

A

Purple

114
Q

What colour does gram negative bacteria stain in iodine?

A

Pink

115
Q

What allows encapsulated organisms to infect an organism?

A

● Prone to causing invasive infections due to
added virulence provided by their
polysaccharide capsule
● The capsule is antiphagocytic (hard to digest)
○ Allows evasion of the immune system
○ Conceals surface proteins that the
innate immune system would
recognise
● The body is dependent on splenic function for
clearing these organisms

116
Q

Serum Fe+

Ferritin

Transferrin Saturation

A

Serum Fe*
Hugely variable during the day

Ferritin*
Primary storage protein & providing reserve, Water soluble

Transferrin Saturation*
Ratio of serum iron and total iron binding capacity – revealing %age of transferrin binding sites that have been occupied by iron

117
Q

Transferrin/Transferrin receptors

A

Made by liver, Production inversely proportional to Fe stores. Vital for Fe transport. Uptake of Fe from protein needs transferrin to be attached to the cell via the transferrin receptor

118
Q

What is total iron binding capacity (TIBC)?

A

Measurement of the capacity of transferrin to bind iron
It is an indirect measurement of transferrin – a transport protein that carries iron
TIBC is technically easier to measure in the laboratory that transferrin levels directly

119
Q

What are TIBC levels in iron deficiency anaemia?

A

TIBC HIGH

more transferrin produced aiming to transport more iron to tissues in need

120
Q

What are TIBC levels in anaemia of chronic disease?

A

TIBC LOW

less transferrin produced (but more ferritin), aim to reduce availability of iron for pathogens. This is mainly regulated by increased hepcidin production.

121
Q

Pernicious anaemia

A

Autoimmune disorder

Gastric Parietal cell antibodies
IF antibodies

Lack of IF
Lack of B12 absorption

Foundations of Clinical Science (4 decks)

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