Haemolytic anaemia

Question 1

What is haemolytic anaemia?

Answer 1

Destruction of the RBCs, resulting in a low Hb concentration.

Question 2

What are some inherited conditions that can lead to chronic haemolytic anaemia?

Answer 2

Many inherited conditions can cause the RBCs to be more fragile and breakdown faster than normal.

Examples include hereditary spherocytosis, hereditary elliptocytosis, thalassaemia, sickle cell anaemia, and G6PD deficiency.

Question 3

What are some acquired conditions that lead to the destruction of RBCs?

Answer 3

Autoimmune haemolytic anaemia, alloimmune haemolytic anaemia (e.g., transfusion reactions and haemolytic disease of the newborn), paroxysmal nocturnal haemoglobinuria, microangiopathic haemolytic anaemia, and prosthetic valve related haemolysis.

Question 4

What are the features of haemolytic anaemia?

Answer 4

Anaemia, splenomegaly (the spleen becomes filled with destroyed RBCs), jaundice (bilirubin is released during the destruction of RBCs).

Question 5

What investigations are carried out for haemolytic anaemia?

Answer 5

FBC (normocytic anaemia), blood film shows schistocytes (fragments of RBCs), direct coomb’s test is positive in autoimmune haemolytic anaemia (not in other types).

Question 6

What is hereditary spherocytosis?

Answer 6

The most common inherited haemolytic anaemia, causing fragile, sphere-shaped RBCs that easily breakdown when passing through the spleen.

Question 7

What type of condition is hereditary spherocytosis?

Answer 7

Autosomal dominant, with likely positive family history.

Question 8

How does hereditary spherocytosis present?

Answer 8

Anaemia, jaundice, gallstones, splenomegaly.

Question 9

How can hereditary spherocytosis present in the presence of parvovirus?

Answer 9

Aplastic crisis.

Question 10

What are the key findings in hereditary spherocytosis?

Answer 10

Raised MCHC on a FBC, raised reticulocyte due to rapid turnover of RBCs, spherocytes on a blood film.

Question 11

How is hereditary spherocytosis treated?

Answer 11

Folate supplements, blood transfusion when needed, splenectomy, cholecystectomy may be needed if gallstones are an issue.

Question 12

What is hereditary elliptocytosis?

Answer 12

Similar to hereditary spherocytosis, but the RBCs are ellipse-shaped. It presents and is managed the same as spherocytosis.

Question 13

What type of condition is hereditary elliptocytosis?

Answer 13

Autosomal dominant.

Question 14

What is G6PD deficiency caused by?

Answer 14

Defect in the gene coding for glucose-6-phosphate dehydrogenase, which is an enzyme responsible for protecting the cells from oxidative damage.

Question 15

What type of condition is G6PD deficiency?

Answer 15

X-linked recessive genetic condition (males are more often affected and females are carriers).

Question 16

Who is G6PD deficiency more common in?

Answer 16

Mediterranean, Asian, and African patients; history of neonatal jaundice.

Question 17

What does G6PD deficiency lead to?

Answer 17

Acute episodes of haemolytic anaemia, triggered by infections (e.g., UTI), drugs, or fava beans (broad beans).

Question 18

What are some key medication triggers for G6PD deficiency?

Answer 18

Ciprofloxacin, sulfonylureas (e.g., gliclazide), sulfasalazine.

Question 19

How does G6PD deficiency present?

Answer 19

Jaundice (often in neonatal period), gallstones, anaemia - pale, breathlessness, splenomegaly.

Question 20

How does G6PD deficiency look on a blood film?

Answer 20

Heinz bodies.

Question 21

How can a diagnosis of G6PD deficiency be made?

Answer 21

G6PD enzyme assay.

Question 22

What is autoimmune haemolytic anaemia (AIHA)?

Answer 22

When antibodies are created against the patient’s own RBCs, leading to haemolysis.

Question 23

What are the two types of AIHA?

Answer 23

Warm and cold, based on the temperature at which the auto-antibodies destroy RBCs.

Question 24

Which type of AIHA is more common?

Answer 24

Warm AIHA, where haemolysis occurs at normal or above normal temperatures.

Question 25

What is the cause of warm AIHA?

Answer 25

Usually idiopathic.

Question 26

What is cold reactive AIHA also called?

Answer 26

Cold agglutinin disease.

Question 27

What happens in cold reactive AIHA?

Answer 27

At lower temperatures (under 10 degrees), the antibodies attach to the RBCs and cause them to clump together (agglutination), activating the immune system and leading to RBC destruction.

Question 28

What can cold AIHA be secondary to?

Answer 28

Lymphoma, leukaemia, SLE, infections (e.g., mycoplasma, EBC, CMV, HIV).

Question 29

What is the management of AIHA?

Answer 29

Blood transfusions, prednisolone, rituximab (MCA against B cells), splenectomy.

Question 30

How is alloimmune haemolytic anaemia caused?

Answer 30

Occurs due to foreign RBCs or foreign bodies.

Question 31

When does alloimmune haemolytic anaemia occur?

Answer 31

In transfusion reactions or haemolytic disease of the newborn.

Question 32

When do haemolytic transfusion reactions occur?

Answer 32

When RBCs are transfused into the patient, leading to the immune system producing antibodies against antigens on the foreign RBCs.

Question 33

What is haemolytic disease of the newborn?

Answer 33

When maternal antibodies cross the placenta from the mother to the fetus, targeting antigens on the RBCs of the fetus and causing destruction of the neonate’s RBCs.

Question 34

What prevents sensitisation in rhesus negative women?

Answer 34

Anti-D prophylaxis.

Question 35

What is paroxysmal nocturnal haemoglobinuria caused by?

Answer 35

A specific genetic mutation in the haematopoietic stem cells in the bone marrow occurring during the patient’s lifetime.

Question 36

What does paroxysmal nocturnal haemoglobinuria result in?

Answer 36

A loss of proteins on the surface of the RBCs that inhibit the complement cascade, leading to their destruction.

Question 37

How does paroxysmal nocturnal haemoglobinuria present?

Answer 37

Red urine in the morning containing Hb and haemosiderin, anaemia, thrombosis (DVT, PE, hepatic vein thrombosis), smooth muscle dystonia.

Question 38

How is paroxysmal nocturnal haemoglobinuria managed?

Answer 38

Eculizumab - MCA that targets complement component 5 (C5), bone marrow transplantation (can be curative).

Question 39

What is microangiopathic haemolytic anaemia (MAHA)?

Answer 39

Involves the destruction of RBCs as they travel through the circulation, often caused by abnormal activation of the clotting system.

Question 40

What is MAHA usually secondary to?

Answer 40

An underlying condition such as haemolytic uraemic syndrome, disseminated intravascular coagulation, thrombotic thrombocytopenic purpura, SLE, or cancer.

Question 41

What is seen on a blood film in MAHA?

Answer 41

Schistocytes.

Question 42

What is a key complication of prosthetic heart valves?

Answer 42

Haemolytic anaemia.

Question 43

In what types of valve replacement does prosthetic valve haemolysis occur?

Answer 43

Both bioprosthetic and metallic valve replacement, but it varies depending on the type.

Question 44

What causes prosthetic valve haemolysis?

Answer 44

Turbulence flow around the valve and the shearing of the RBCs.

Question 45

What does management of prosthetic valve haemolysis involve?

Answer 45

Monitoring, oral iron and folic acid supplementation, blood transfusions if severe, revision surgery may be needed in severe cases.