Anaemia - MedED

Question 1

Differentiate between IDA and ACD

Answer 1

IDA - everything low except transferrin and TIBC

ACD - everything low except ferritin, mainly normocytic

Question 2

Causes of IDA

Answer 2

Malabsorption:
Malnutrition
Coeliac disease
IBD

Increased use:
Pregnancy
Growth

Increased loss:
menorrhagia 
GI malignancy
Peptic ulcer
IBD

Question 3

Key blood film features of IDA

Answer 3

Pencil cells
Hypochromia
Aniso-poikilocytosis

Question 4

Four types of alpha thalassemia and their complications

Answer 4

Alpha +
Alpha *
Hb H (lack 3 alpha genes, requires blood transfusion for life)
Hb barts (death in utero)

Question 5

Three types of beta thalassemia and their complications

Answer 5

Beta minor - mild anaemia but disportionately low MCV)
Beta intermedia
Beta major (severe anaemia presenting in first few months of life, requiring transfusion for life)

Question 6

Epidemiology of Thalassemia

Answer 6

Cyprus

Question 7

Investigations for thalassemia - also what is the gold standard?

Answer 7

Microcytic anaemia + film
Normal iron studies
Gel electrophoresis (gold standard)

Question 8

Explain the haemoglobin shift from fetus to infancy and why alpha and beta thalassemia present at different time stages

Answer 8

In utero - gamma globin + alpha
Hence alpha presents before birth
You switch to beta globin around 3-6m so beta thalassemia presents in infancy

Question 9

Explain sickle cell disease and its complications

Answer 9

Point mutation in beta globin chain on chromosome 11.

The beta subunit has the amino acid valine at position 6 instead of the glutamic acid that is normally present.

Autosomal recessive.

Sickling makes the rbc more prone to intravascular haemolysis, therefore you get haemolytic jaundice.

Question 10

What might precipitate sickling?

Answer 10

Hypoxia
Dehydration
Acidosis
Infection esp capsuled infections

Question 11

Why are sickle cells/thalassemia though to be evolutionary advantages?

Answer 11

Both sickle cell disease and thalassemia prevent malaria falciparum from actually hijacking the actin from rbc, thus preventing it from adhering to other RBCs and the spread of the disease.

Question 12

Blood film findings for sickle cell disease

Answer 12

Howell-Jolly bodies (spots within a cell) - these are nuclear remnants which are usually filtered out by the spleen. They signify poor spleen function due to splenic infarcts from vasoocclusion.

Question 13

Life span of a sickled blood cell

Answer 13

10-20 days

Question 14

Complications of sickle cell disease

Answer 14

Acute painful crisis
Stroke (vasoocclusion)
Sequestration crisis in spleen, as all faulty rbc get stuck in spleen causing splenomegaly
Chronic cholecystitis

Question 15

What do howell-jolly bodies mean?

Answer 15

Spleen no longer working

You might see hyposplenism

Question 16

How do you manage an acute painful crisis?

Answer 16

Sickle Acute Painful Crisis

Saturate with oxygen
Antibiotics if needed
Pain relief
Cannula for IV fluids

Question 17

Diagnosis of sickle cell anaemia

Answer 17

Hb electrophoresis and blood film

Question 18

Symptoms of sickle cell anaemia

Answer 18

Dactylitis 
Priapism 
Haemolytic anaemia causing jaundice 
Acute chest syndrome?
Aplastic crisis due to parvovirus B19

Question 19

Mx of sickle cell anaemia

Answer 19

Conservative: trigger avoidance + vaccination
Medical: Hydroxyurea + prophylatic abx
Surgical - bone marrow transplant

Question 20

What is seen on the blood film of someone with B12/folate deficiency?

Answer 20

Macrocytic, MEGALOBLASTIC anaemia (hypersegmented neutrophils)

Question 21

Causes of vit B12 and folate deficiencies

Answer 21

Causes of both:
Alcohol
IBD/coeliac

Folate:
Pregnancy
Anitfolate drugs

B12:
Pernicious anaemia
Dietary malabsorption

Question 22

How long do B12 stores last?

Answer 22

3-4 years

Question 23

How long do folate stores last?

Answer 23

6 months

Question 24

What neurological complication is associated with B12 deficiency?

Answer 24

Subacute combined degeneration of the cord

Glove and stocking parasthesia
Hyporeflexia
Romberg’s positive

Question 25

Antibodies in pernicious anaemia

Answer 25

Anti intrinsic factor

Anti parietal cells

Question 26

Types of haemolytic anaemias

Answer 26

Disorders of membrane - hereditary spherocytosis

Disorders of enzyme - G6PD

Disorders of haeoglobin thalassemia / sickle cell

Intravascular

Extravascular (in spleen)

Question 27

Signs of haemolytic anaemia

Answer 27

Low Hb
Low haptoglobin (as it is exhausted?)
Unconjugated bilirubin is raised
LDH raised as leaks out form cells

Question 28

Glucose 6 phosphate deficiency - pathophysiology

Answer 28

Reduces glutathione stores which are really important for dealing with oxidative stress.

Question 29

What foods should people with G6PD avoid?

Answer 29

Broad beans / fava beans
Napthalene moth balls
Antimalaraials (quinines)

Question 30

Hereditary pattern of G6PD

Answer 30

oXidative stress; X linked

Question 31

What is seen on the blood film of someone with G6PD?

Answer 31

Heinz bodies (active haemolysis, intracellular inclusions of denatured haemoglobin)

Bite cells (where the spleen has taken a ‘bite’ out of the cell)

Question 32

A haemolytic disease affecting white people

Answer 32

Hereditary spherocytosis

Question 33

Hereditary spherocytosis key features, cause

Answer 33

Spherocytes

Beta spectrin/ankyrin deficiency causing weak cytoskeleton and globular RBC

Question 34

Test for HS

Answer 34

Osmotic fragility test - give the patient hypotonic saline; it stresses out the rbc and causes them to break down

Question 35

New test for HS

Answer 35

Osmotic fragility test - give the patient hypotonic saline; it stresses out the rbc and causes them to break down

New test: Eosin-5-maleimide binding blood test

Question 36

What test comes back negative for HS?

Answer 36

Coombs test (testing for antibodies against RBC)

Question 37

What is a major complication of sickle cell anaemia and hereditary spherocytosis and why?

Answer 37

APLASTIC CRISIS

Parvovirus B19 infections bone marrow, so body relies on circulating RBC to function. However RBC in HS lasts around 30 days, and in sickle cell, around 10 days, so you FAIL TO PRODUCE RED BLOOD CELLS.