Hyposplenism

Overview

The roles of the spleen are to filter the blood to remove old and damaged blood cells, create new blood cells, and store platelets. It plays a key role in the body’s immune system. The spleen consists of white pulp and red pulp:

• White pulp:
  • Contains B- and T-lymphocytes that recognise and attack pathogens
• Red pulp:
  • Removes old and damaged red blood cells
  • Stores platelets
  • Produces new red blood cells in foetuses – this stops after birth

Hyposplenism

Hyposplenism describes a reduction in spleen function. This can be due to:

• Sickle cell anaemia
• Thalassaemia
• Lymphoma
• Leukaemia
• Coeliac disease
• Ulcerative colitis
• Essential thrombocytosis

Blood films usually show Howell-Jolly bodies in hyposplenism. They may also show Pappenheimer bodies and target cells.

Complications

Since the spleen plays a role in the immune system, complications may be:

• Severe infection due to encapsulated bacteria, the most common being Streptococcus pneumoniae, followed by Haemophilus influenzae type b (Hib) and Neisseria meningitidis.
• Severe infection to malaria

Management

All patients

• 1^st-line: immunisations + antibiotic prophylaxis:
  • 5-yearly pneumococcal vaccinations
  • Antibiotics used are oral phenoxymethylpenicillin or erythromycin