Anaemia - Haemolytic

Question 1

What are the 4 types of alpha thalassaemia?

Describe the genetic basis of each.

Answer 1

Alpha thalassaemia trait (-a/aa)
Alpha thalassaemia trait (–/aa or -a/-a)
Alpha thalassaemia minor (–/-a)
Alpha thalassaemia major (–/–)

Question 2

What is haemoglobin H disease?

Answer 2

Alpha thalassaemia minor (–/-a)

Question 3

What is haemoglobin Bart’s anaemia?

Answer 3

Alpha thalassaemia major (–/–)

Question 4

Describe the clinical features of alpha thalassaemia trait. (1)

What features would be seen in the blood? (3)

Answer 4

SYMPTOMS:
Asymptomatic

BLOOD:
Decreased MCV
Elevated RBC count
Possible mild anaemia

Question 5

Describe the clinical features of alpha thalassaemia minor. (3)

What features would be seen in the blood? (4)

Answer 5

SYMPTOMS:
Hepatosplenomegaly
Jaundice
Leg ulcers

BLOOD:
Haemolytic anaemia
Haemoglobin <75g/L
Decreased MCV
Variously shaped RBCs

Question 6

Describe the clinical features of alpha thalassaemia major. (1)

Answer 6

Incompatible with life

Question 7

What are the 2 types of mutation which cause beta thalassaemia?

Answer 7

B+ - insufficient B chain production

B0 - no B chain production at all

Question 8

What are the 3 types of beta thalassaemia?

Describe the genetic basis of each.

Answer 8

Beta thalassaemia trait (B/B+)

Beta thalassaemia intermedia (B+/B+)

Beta thalassaemia major (B0/B0)

Question 9

What is Cooley’s anaemia?

Answer 9

Beta thalassaemia major (B0/B0)

Question 10

Describe the clinical features of beta thalassaemia trait. (1)

What features would be seen in the blood? (2)

Answer 10

SYMPTOMS:
Asymptomatic

BLOOD:
Mild anaemia
Slight increased in HbF

Question 11

Describe the clinical features of beta thalassaemia intermedia. (1)

What features would be seen in the blood? (1)

Answer 11

SYMPTOMS:
Splenomegaly

BLOOD:
Moderate anaemia

Question 12

Describe the clinical features of beta thalassaemia major. (4)

What features would be seen in the blood? (5)

Answer 12

SYMPTOMS:
Failure to thrive
Extramedullary haemopoiesis, e.g.
-Abnormal head shape (bossing)
-Hepatosplenomegaly
Osteopenia
"Hair on end" sign on skull x-ray

BLOOD:
Severe microcytic, hypochromic anaemia
Target cells
Nucleated RBCs
Elevated HbF
Absent HbA

Question 13

What is sickle cell anaemia caused by?

Answer 13

Abnormal haemoglobin (HbS) due to abnormally shaped B chains

Question 14

Describe the clinical features of sickle cell anaemia. (5)

Answer 14

Well-tolerated anaemia
Hyposplenism

Acute sickle cell crises:

• Painful microvascular occlusion
• Organ failure

Question 15

In sickle cell anaemia, what features would be found on examination of the blood? (5)

Answer 15

Sickle-shaped RBCs
Target cells
Elevated reticulocytes
Haemolysis
Elevated unconjugated bilirubin

Question 16

In warm autoimmune haemolytic anaemia, what features would be found on examination of the blood? (5)

Answer 16

Spherocytes
Reticulocytes
Nucleated RBCs
Polychromatic RBCs
Positive Coombs' test

Question 17

In cold autoimmune haemolytic anaemia, what features would be found on examination of the blood? (2)

Answer 17

Cold agglutinins (anti-I antibody)
Positive Coombs' test

Question 18

In haemolytic disease of the newborn, what features would be found on examination of the blood? (3)

Answer 18

Nucleated RBCs
Elevated reticulocytes
Positive Coombs’ test

Question 19

List 6 causes of fragmentation haemolysis.

Answer 19

Mechanical heart valves
Blood vessel abnormalities
DIC
HUS
Hyperplenism

Drugs, e.g.

• Acute lead poisoning
• Copper toxicity
• Spider/snake venom

Question 20

In fragmentation haemolysis, what features would be seen on examination of the blood? (1)

Answer 20

Fragmented RBCs