Hypochromic microcytic anaemia

Question 1

What is hypochromic microcytic anaemia?

Answer 1

Microcytosis is a term used to describe red blood cells that are smaller than normal.

Hypochromic means that the red blood cells have less haemoglobin than normal. Low levels of haemoglobin in your red blood cells leads to appear paler in colour.

In microcytic hypochromic anaemia, your body has low levels of red blood cells that are both smaller and paler than normal

Question 2

Causes of hypochromic microcytic anaemia?

Answer 2

Iron deficiency anaemia.
Sideroblastic anaemia
Thalassaemias

Question 3

What are the signs & symptoms of Iron deficiency anaemia (IDA)?

Answer 3

Fatigue 
Pica 
Nail changes 
Hair loss 
Dysphagia 
Glossitis and angular stomatitis 
Impaired muscular performance 
Gastric difficulties 
Growth impairment 
Recurrent infections 
Restless leg syndrome 
Dyspnoea 
Lesion on rectal examination

Question 4

What are the risk factors for IDA?

Answer 4

Black women 
Pregnancy 
Vegan 
Menorrhagia 
Hookworm infection 
Haemodialysis
Coeliac disease 
Gastrectomy 
NSAID use 
Obesity 
H.pylori

Question 5

What are the tests and investigations for IDA?

Answer 5

FBC- MCV (less than 80 fL), MCH (low) ,MCHC (low)
Peripheral blood smear
Reticulocye count- low
Iron studies-serum iron (low), serum ferritin (low), TIBC (increased)
Endoscopy to rule out malignancy

Question 6

What is included in the management of IDA?

Answer 6

Oral ferrous sulphate, IV if not tolerated

SE: GI discomfort and black stools

Question 7

What causes IDA?

Answer 7

This occurs when iron absorption from the diet is not sufficient to cover iron losses.

Question 8

Causes of iron deficiency?

Answer 8

4 major categories in the causes of iron deficiency leading to IDA:

• Decreased iron intake because of inadequate diet or impaired malabsorption.
• Increased iron loss
• Increased iron’s requirement because of infancy, pregnancy or lactation.
• Unknown cause

Question 9

Causes of iron loss

Answer 9

GI bleeding (usually unknown lesion)
Menorrhagia
Blood donation
Haemoglobinuria
Self-induced bleeding
Idiopathic pulmonary haemosiderosis
Good pasture's syndrome
Hereditary haemorrhagic telangiectasia
Angiodysplasia
Disorders of haemostasis
Chronic renal failure 
Haemodialysis 
Runner's anaemia

Question 10

Thalassaemias

Answer 10

This is also a microcytic haemolytic anaemia.
Thalassemia is an inherited blood disorder in which the body makes an abnormal form of haemoglobin.
The disorder results in excessive destruction of red blood cells, which leads to anaemia.

Question 11

How many types of thalassaemias are there?

Answer 11

Two.

Alpha and beta thalassaemias.

Question 12

What is Beta thalassaemia?

Answer 12

This is usually caused by point mutations in B-globin genes on chromosome 11, leading to a decrease in the production of B-globin or its absence.

Question 13

How many types of the presentation can you get with beta thalassaemia?

Answer 13

BT minor
BT intermedia
BT major

Question 14

What is BT minor?

Answer 14

Heterozygous carrier state, asymptomatic
Mild, well-tolerated anaemia may worsen during pregnancy.
Diagnosed with increased HbAz.

Question 15

What is BT intermedia?

Answer 15

Mild homozygous mutations.
Moderate anaemia, but not requiring transfusions.
May cause splenomegaly.

Question 16

What is BT major?

Answer 16

Significant abnormalities in both B-globin genes.
Presenting after 6 months of age with anaemia and failure to thrive.
Extramedullary haematopoiesis occurs, causing skull bossing and hepatosplenomegaly with osteopenia.

Question 17

Tests for BT?

Answer 17

FBC 
MCV 
Blood film (in major disease, marked anisocytosis (different cell sizes) and poikilocytosis (different cell shapes). Hypochromic and microcytic.
HbA2
HbF
Hb electrophoresis

Question 18

Management of BT?

Answer 18

Fitness
Healthy diet
Folate supplementation
Regular, life-long blood transfusions to keep Hb>90 g/l
Iron overload can cause cardiac problems, hypothyroidism, hypocalcaemia and hypogonadism- Iron chelators are given such as deferasirox PO and desferrioxamine SC
Splenectomy if hypersplenism persists, best left till after 5 years due to risk of infections.
Hormonal replacement/treatment for endocrine complications.
A bone marrow transplant may be curative- 1 in 8 chance of a suitable donor.

Question 19

What is alpha thalassaemia?

Answer 19

Genetic deletions in the 2 a-globin genes on each chromosome 16 i.e 4 genes.

Question 20

Presentation of AT?

Answer 20

If all 4 genes are deleted, death in utero (Bart’s hydrops fetalis)
Haemoglobin H disease (HbH) occurs if 3 genes are deleted, with moderate anaemia and features of haemolysis: hepatosplenomegaly, leg ulcers, jaundice, blood film similar to major BT.
If two genes deleted, there is an asymptomatic carrier state, with decreased MCV
If one gene deleted, normal clinical state

Question 21

Tests of AT?

Answer 21

FBC 
MCV 
Blood film 
Iron 
HbA2 
HbF 
HB electrophoresis 
Howell-jolly bodies in RBCs seen in films

Question 22

Management of AT?

Answer 22

Fitness
Healthy diet
Folate supplementation
Regular, life-long blood transfusions to keep Hb>90 g/l
Iron overload can cause cardiac problems, hypothyroidism, hypocalcaemia and hypogonadism- Iron chelators are given such as deferasirox PO and desferrioxamine SC
Splenectomy if hypersplenism persists, best left till after 5 years due to risk of infections.
Hormonal replacement/treatment for endocrine complications.
A bone marrow transplant may be curative- 1 in 8 chance of a suitable donor.

Question 23

What is sideroblastic anaemia?

Answer 23

Sideroblastic anaemia is a group of blood disorders characterized by an impaired ability of the bone marrow to produce normal red blood cells.

There are many potential causes of sideroblastic anaemia.

Depending on the cause, it can be classified as hereditary (sometimes called congenital), acquired, and idiopathic (cause unknown).

Question 24

Pathophysiology of sideroblastic anaemia?

Answer 24

In this condition, the iron inside red blood cells is inadequately used to make haemoglobin, despite normal amounts of iron.
As a result, iron accumulates in the red blood cells, giving a ringed appearance to the nucleus (ringed sideroblast).

Question 25

Signs and symptoms of sideroblastic anaemia?

Answer 25

Fatigue
Breathing difficulties
Weakness
Enlargement of the liver or spleen.

Question 26

What is IRIDA?

Answer 26

A hereditary disorder marked by with iron deficiency anaemia that is typically unresponsive to oral iron supplementation and may be only partially responsive to parenteral iron therapy.

Question 27

Pathophysiology of IRIDA

Answer 27

IRIDA results from variants in the TMPRSS6 gene that lead to uninhibited production of hepcidin. IRIDA is characterised by microcytic, hypochromic anaemia and serum hepcidin values that are inappropriately high for body iron levels.