Microcytic anaemia

Question 1

What MCV range is classified as microcytic?

Answer 1

<80

Question 2

What are causes of microcytic anaemia?

Answer 2

Iron deficiency
Thalassemia
Sideroblastic anaemia
Chronic disease

Question 3

What is the most common anaemia worldwide?

Answer 3

Iron deficiency anaemia

Question 4

What is iron used for in the body?

Answer 4

Absorbed and circulates bound to transferrin. Stored as ferritin or incorporated into core of haemoglobin

Allows oxygen to be carried around the body.

Component of myoglobin (stores and releases oxygen to muscle tissues)
DNA synthesis and repair
Detoxification
Other uses

Question 5

What does Fe deficiency cause?

Answer 5

Impaired haemoglobin synthesis

Question 6

What are causes of Fe deficiency

Answer 6

Malnutrition
Breastfeeding for too long (not good source of Fe)
Malabsorption eg Coeliac, IBD
Menorrhagia (long periods)
Hookworm (most common worldwide cause, causes GI bleeding)

In elderly = red flag for colon cancer bleeding needing urgent endoscopy

Question 7

Decreased haemoglobin synthesis result in m_____ anaemia

Answer 7

Microcytic

Question 8

What are symptoms of iron deficiency anaemia?

Answer 8

Fatigue
Weakness
Koilonychia (concave shaped nails)
Angular stomatitis (ulceration at corners of mouth)
Atrophic glossitis (enlarged tongue)

Question 9

What investigations would be carried out for suspected iron deficient anaemia?

Answer 9

FBC (to see microcytic)

Blood film: Hypochromic RBCs,
Target cells (non-specific bullseye pattern of cells)
Howell Jolly bodies (non-specific nucleated RBCs)

Fe studies:
Decreased serum Fe
Decreased ferritin
Decreased transferrin saturation
Increased TIBC (total iron-binding capacity)

Question 10

If there is an iron deficiency in >60, what else should be carried out?

Answer 10

Endoscopy

Question 11

What is the treatment for iron deficiency?

Answer 11

Ferrous sulphate

Question 12

What are side effects of ferrous sulphate?

Answer 12

Diarrhoea/ constipation
Black stool

Question 13

If ferrous sulfate is poorly tolerated, what can be considered instead?

Answer 13

Ferrous gluconate

Question 14

What is thalassemia?

Answer 14

Abnormal inherited blood disorders characterised by abnormal haemoglobin production
Haemoglobinopathy

Question 15

What are the two main types of thalassemia?

Answer 15

Alpha and beta (to do with what part of haemoglobin molecule is affected)

Question 16

What is alpha thalassemia?

Answer 16

Deficiency or absence of alpha-globin chains in haemoglobin.
Severity depends on number of affected genes (get 2 from each parent)
Deletions from 4 genes on chromosome 16

Associated with an abnormal haemoglobin isoform

Question 17

What other condition is alpha thalassemia associated with?

Answer 17

Choriocarcinoma

Question 18

What is beta thalassemia

Answer 18

Deficiency of absence of beta-globin chains in haemoglobin
Depends on mutations in these genes (1 from each parent)
Mutations of 2 genes on chromosome 11

Get normal haemoglobin isoforms, just depletion of beta-chains.

Question 19

What are common symptoms of thalassemia?

Answer 19

Anaemia, splenomegaly, hepatomegaly, bone deformities, growth retardation, jaundice, fatigue and weakness

“Chipmunk faces” = massively enlarged forehead and cheekbones due to extramedullary haematopoiesis, so is RBC production here

Often get gallstones and failure to thrive

Question 20

How is suspected thalassemia investigated?

Answer 20

FBC
Blood film = hypochromic RBCs, target cells, microcytic anaemia with increased reticulocytes.

Haemoglobin electrophoresis

X-ray showing “hair on end” signs for increased bone marrow activity

Question 21

How do you treat thalassemia?

Answer 21

Regular blood transfusions

Iron chelation therapy (to manage iron overload from having regular transfusions)

After age of 6, can have splenectomy (due to splenomegaly /overactive spleen destroying RBCs contributing to anaemia)

Folate supplements

Bone marrow stem cell transplantation

Question 22

What are side effects of iron chelation therapy?

Answer 22

Deafness
Cataracts

Question 23

Thalassemia is often found where what other condition is present?

Answer 23

Malaria

Question 24

Is alpha or beta thalassemia more common?

Answer 24

Beta thalassemia

Question 25

What is sideroblastic anaemia?

Answer 25

Defective haemoglobin synthesis within the mitochondria
Often X-linked inherited condition

Question 26

In sideroblastic anaemia, there is often a deficiency in what enzyme?

Answer 26

ALA synthase (catalyses the precursor to haems)

Question 27

Sideroblastic anaemia is characterised by presence of ringed sideroblasts (abnormal RBC precursors containing iron) in the…

Answer 27

bone marrow

Question 28

In sideroblastic anaemias there is impaired utilisation of ___ in the process of heme synthesis

Answer 28

iron

Question 29

In sideroblastic anaemia, there is an accumulation of iron in the _____ of developing RBCs.

Answer 29

mitochondria

Question 30

What causes sideroblastic anaemia?

Answer 30

Can be genetic

Can develop in adulthood due to myelodysplastic syndrome (MDS), certain meds, toxins or vitamin B deficiency

Question 31

What investigations should be taken for suspected sideroblastic anaemia?

Answer 31

FBC and blood film showing microcytic with ringed sideroblasts and increased basophilic granules

Fe studies showing increased serum FE, increased ferritin, increased transferrin sats, decreased TIBC (total iron binding capacity)

Question 32

What is treatment for sideroblastic anaemia?

Answer 32

Discontinue any causative meds, manage any MDS
Blood transfusions, B6 supplementation