Anaemia - Hereditary Spherocytosis (Normocytic)

Question 1

Definition

Answer 1

Autosomal dominant membranopathy

Question 2

Epidemiology

Answer 2

Most common haemolytic anaemia in NORTHERN EUROPEANS
Also, effects AMERICANS
Rare in black people

Question 3

Pathophysiology

Answer 3

Deficiency in structural membrane protein SPECTRIN = makes RBCs more spherical and RIGIDER = cells get stuck in spleen as unable to pass through splenic microcirculation + shortened lifespan = increased splenic recycling (extravascular haemolysis) causes splenomegaly as rigid - risk of auto splenectomy

Question 4

Signs

Answer 4

General anaemia
NEONATAL JAUNDICE
SPLENOMEGALY
GALL STONES - from chronic haemolysis (50%)

Question 5

Symptoms

Answer 5

Fatigue
Pallor
Dizziness
Palpitations
RUQ pain from gallstones
Failure to thrive

Question 6

Diagnosis

Answer 6

FBC + Blood film
Negative direct coombs test
Positive AHA
No further tests needed if:
- Family history
- Typical features
- Positive lab investigations
= spherocytosis
= raised MCV
= Increased reticulocytes

Question 7

Treatment

Answer 7

SPLENECTOMY (Decrease extravascular haemolysis)
- wait until at least 6 years old due to sepsis risk as spleen fights off encapsulated bacteria
+ folate supplements, transfusions
NEONATAL JAUNDICE = Phototherapy

Question 8

Why is phototherapy essential in neonatal jaundice?

Answer 8

Risk of KERNICTERUS if untreated (bilirubin accumulates in basal ganglia, CNS dysfunction + death)

Question 9

Complications

Answer 9

Auto-splenectomy
Gallstones
Aplastic crisis
Bone marrow expansion
Post splenectomy sepsis