Quesmed videos (haemolytic anaemia 1+2)

Question 1

What is haemolytic anaemia?

Answer 1

A disorder in which red blood cells are destroyed faster than they can be made.

The destruction of red blood cells is called haemolysis.

Question 2

What features would indicate haemolytic anaemia?

Answer 2

Examination findings: splenomegaly and jaundiced sclera with pale conjunctiva.

Low haemoglobin

Schistocytes (fragmented RBC’s)

Raised unconjugated bilirubin

Question 3

What is a feature of a patients past surgical history that would make haemolytic anaemia more likely?

Answer 3

The insertion of a prosthetic heart valve (especially a metal one).

Question 4

How can prosthetic heart valves cause intravascular haemolytic anaemia?

Answer 4

Since the turbulent blood flow around the mechanical valve causes mechanical damage to the erythrocytes (RBC’s).

Question 5

Why is unconjugated bilirubin raised in haemolytic anaemia?

Answer 5

Haemoglobin from destroyed erythrocytes (RBC’s) is broken down into globin (which is recycled) and haem.

The haem is further broken down into iron and unconjugated bilirubin.

Question 6

What type of anaemia does haemolysis cause?

Answer 6

Normocytic anaemia (normal MCV on blood film)

Erythrocytes are normal sized however there is fewer in the blood due to increased destruction.

Question 7

What are the causes of microcytic anaemia (TAILS)?

Answer 7

Remember: TAILS

Thalassaemia

Anaemia of chronic disease

Iron deficiency anaemia

Lead poisoning

Sideroblastic anaemia

Question 8

What are the causes of normocytic anaemia (ABCD)?

Answer 8

Remember: ABCD

Acute blood loss

Bone marrow failure

Chronic disease

Destruction of RBC’s (haemolysis)

Question 9

What are the causes of macrocytic anaemia (FAT RBC)?

Answer 9

Remember: FAT RBC

Foetus (pregnancy)

Alcohol excess

Thyroid

Reticulocytosis (increased immature RBC’s)

B12 and folate deficiency

Cirrhosis or chronic liver disease

Question 10

What does haemolysis do to reticulocyte count?

Answer 10

Raises the reticulocyte count because the bone marrow is attempting to compensate for the increased destruction of erythrocytes.

Question 11

What is LDH?

Answer 11

An intracellular enzyme released into the serum when erythrocytes are broken down.

Question 12

What is haptoglobin?

Answer 12

A glycoprotein which binds to free haemoglobin in the serum and transports it to the reticulo-endothelial system for breakdown.

Question 13

How is haptoglobin affected in intravascular haemolysis?

Answer 13

In intravascular haemolysis, there are greater amounts of haemoglobin in the serum that bind to haptoglobin.

This is then removed and taken to the reticuloendothelial system resulting in less haptoglobin overall.

Question 14

What are the 2 main haemolysis types?

Answer 14

Intravascular and extravascular haemolysis

Question 15

Why is reticulocyte count high in haemolytic anaemia?

Answer 15

Haemolysis triggers the kidneys to produce erythropoietin which triggers the bone marrow to produce reticulocytes.

This is the bodies mechanism for trying to compensate for the decrease in haemoglobin and RBC’s.

Question 16

What is the most common type of haemolysis?

Answer 16

Extravascular haemolysis

Question 17

Where does extravascular haemolysis occur?

Answer 17

Reticulo-endothelial system (liver and spleen)

Question 18

What is the mechanism of extravascular haemolysis?

Answer 18

Macrophages in the liver, spleen, bone marrow and lymph nodes engulf and destroy the erythrocytes in the reticulo-endothelial system.

Typically presents with splenomegaly and hepatomegaly on examination.

As well as high levels of unconjugated bilirubin.

Question 19

Where does intravascular haemolysis occur?

Answer 19

Within the bloodstream where RBC’s are destroyed within the blood vessels

Question 20

What is the mechanism of intravascular haemolysis?

Answer 20

Characterised by the rupture or lysis of red blood cells, leading to the release of haemoglobin into the bloodstream.

Haemoglobin released from lysed red blood cells may bind to haptoglobin or be filtered by the kidneys, leading to the presence of haemoglobin in the urine (haemoglobinuria).

Question 21

What is the classic presentation for haemolytic anaemia?

Answer 21

Fatigue, pallor, SOB and tachycardia.

Jaundice

Splenomegaly

Gallstones

Dark urine - haemoglobinuria (occurs with intravascular haemolysis)

Signs of underlying disorder e.g. malar rash in SLE, may be contributing factor to haemolysis.

Question 22

What is the cause of jaundice in haemolytic anaemia?

Answer 22

Bilirubin released as a breakdown product of haemoglobin causing raised unconjugated bilirubin.

Question 23

What is the cause of splenomegaly (and possible hepatomegaly) in haemolytic anaemia?

Answer 23

Enlarged spleen since spleen is being filled with damaged RBC’s

Question 24

What is the cause of gallstones in haemolytic anaemia?

Answer 24

Increased bilirubin levels

Question 25

What is the cause of dark urine in haemolytic anaemia?

Answer 25

Caused by haemoglobinuria (occurs with intravascular haemolysis)

Question 26

What is G6PD deficiency?

Answer 26

Deficiency of Glucose-6-Phosphate Dehydrogenase

Question 27

Inheritance pattern of G6PD deficiency?

Answer 27

X-linked recessive

Question 28

Features of G6PD deficiency?

Answer 28

Usually in those with Mediterranean and African ethnicity

Neonatal jaundice

Episodic intravascular haemolysis triggered by oxidative stress

Question 29

What are the triggers for G6PD deficiency?

Answer 29

Intercurrent illness or infection

Fava beans

Henna

Medications(i.e. nitrofurantoin, colchicine, chloroquine).

Question 30

What medications can trigger G6PD deficiency?

Answer 30

Dapsone, nitrofurantoin and NSAID’s

Question 31

What is present in blood film for G6PD deficiency?

Answer 31

Heinz bodies (typically in response to oxidative stress)

Bite cells (erythrocytes with an irregular membrane caused by splenic macrophages attempting to remove Heinz bodies from inside erythrocytes).

Question 32

Diagnostic test for G6PD deficiency?

Answer 32

G6PD enzyme assay

Question 33

Treatment for G6PD deficiency?

Answer 33

Avoidance of precipitants, may require transfusions during acute episodes.

Question 34

What are target cells?

Answer 34

RBC’s showing a target-like appearance on blood film

Question 35

What are target cells usually an indication of?

Answer 35

Haemoglobinopathies such as thalassemia, where abnormal haemoglobin production affects red blood cell shape.

Liver diseases such as obstructive jaundice or cirrhosis, where altered lipid metabolism affects red blood cell membrane composition.

Iron deficiency anaemia or other conditions causing decreased red blood cell volume, leading to relative excess membrane.

Question 36

What are burr cells on blood film?

Answer 36

Burr cells, also known as echinocytes, are red blood cells with numerous small, evenly spaced projections on their surface, giving them a spiky or thorny appearance.

Question 37

What is a condition that may cause burr cell presence?

Answer 37

Disseminated intravascular coagulation (DIC), a disorder characterised by widespread activation of coagulation, leading to microvascular thrombosis and haemolysis.

Question 38

What are Howell-jolly bodies?

Answer 38

Howell-Jolly bodies are small, round, basophilic inclusions found within red blood cells.

Howell-Jolly bodies are remnants of the cell nucleus that are normally removed from mature red blood cells during their development in the bone marrow.

Question 39

What could howell jolly bodies indicate?

Answer 39

Splenectomy: Removal of the spleen can lead to Howell-Jolly body formation due to the absence of the spleen’s filtering function.

Megaloblastic anemia: Certain conditions causing impaired DNA synthesis, such as vitamin B12 deficiency or folate deficiency, can result in Howell-Jolly body formation.

Myelodysplastic syndromes or other bone marrow disorders: In some cases, Howell-Jolly bodies may be seen in individuals with abnormalities in bone marrow function.

Question 40

What are pappenheimer bodies on blood film?

Answer 40

Pappenheimer bodies appear as small, irregular, blue-staining granules within red blood cells when viewed under a microscope.

Question 41

What does the presence of pappenheimer bodies mean?

Answer 41

The presence of Pappenheimer bodies on a blood film can indicate the accumulation of iron within red blood cells.

This iron accumulation may be a result of various conditions affecting iron metabolism or conditions associated with increased iron uptake or storage.

Question 42

What conditions do pappenheimer bodies indicate?

Answer 42

Sideroblastic anemia: A group of disorders characterised by impaired haem synthesis, leading to the accumulation of iron within red blood cell precursors (erythroblasts) and mature red blood cells.

Iron overload disorders: Conditions such as hemochromatosis or transfusional iron overload can result in excess iron deposition within red blood cells and other tissues.