Hyposplenism
Prevention and treatment of infection in patients with an absent or hypofunctional spleen: A British Society for Haematology guideline. Published: Apr 2024.
Background Information
Definition
Hyposplenism is a state of reduced or absent splenic function, resulting in impaired clearance of abnormal blood cells and reduced immune function
Aetiology
Causes of hyposplenism include:
- Surgical splenectomy (indications include hereditary spherocytosis, selected cases of thalassaemia, refractory ITP, splenic rupture / high-grade splenic injury)
- Splenic embolisation
- Functional hyposplenism (medical causes)
- Sickle cell disease
- Coeliac disease
- Haemolytic anaemia (e.g. spherocytosis)
Complications
The main complication is the risk of overwhelming infections caused by encapsulated bacteria:
- Streptococcus pneumoniae (pneumococcus) – most common
- Neisseria meningitidis (meningococcus)
- Haemophilus influenzae type b (Hib)
The spleen (a secondary lymphoid organ) plays an important role in defence against encapsulated bacteria by producing IgM antibodies and activating the complement system.
Another key complication is increased risk of thromboembolic complications (due to persistent thrombocytosis and altered platelet function)
- DVT
- PE
- Stroke and ischaemic heart disease
Diagnosis
Investigation and Diagnosis
| Peripheral blood film findings |
|
| FBC findings |
|
| Imaging |
|
| Confirmatory test |
|
Management
Patient Education
- Patients should carry an alert card (risk of overwhelming infection)
- Educate about potential risks of overseas travel – esp. malaria and those associated with animal bites
Prevention of Overwhelming Infection
There are 2 main domains of management to prevent overwhelming infection in those with hyposplenism.
Vaccinations
The following vaccinations are recommended for those with hyposplenism:
| Vaccination | Timing |
|---|---|
| Influenza | Yearly, to provide seasonal protection |
| COVID-19 | 2-dose (3 months apart) |
| Pneumococcal | One-off (irrespective of prior vaccination), then 5-yearly booster |
| Meningococcal ACWY | One-off (irrespective of prior vaccination) |
| Haemophilus influenzae | To be given as part of routine childhood immunisation
Routine re-vaccination is NOT recommended |
Vaccines should ideally be administered 2 weeks before or 2 weeks after splenectomy, such that:
- In elective splenectomy: give the vaccines 2 weeks before the surgery (to allow adequate antibody production)
- In emergency splenectomy: give the vaccines 2 weeks after the surgery (to allow recovery of immune function and optimise the vaccine response)
If one learns the at risk encapsulated bacteria listed above (pneumococcus, meningococcus, Hib) + influenza and COVID-19, that’s essentially what vaccination should be given to those with hyposplenism.
Antibiotic Prophylaxis
Indications
3 main scenarios:
| Patient population | Antibiotic prophylaxis duration |
|---|---|
| Post-splenectomy patients | ALL patients should continue for 1-3 years post-splenectomy |
| Children | ALL children should continue until 5 y/o (with at least 2 complete years of prophylaxis) |
Patients at high risk of invasive pneumococcal disease
|
Lifelong antibiotic prophylaxis |
Choice of Antibiotics
Aim to prevent pneumococcal infection:
- 1st line: phenoxymethylpenicillin (penicillin V)
- 2nd line: erythromycin
Prevention of Thrombotic Complications
Individualised thromboprophylaxis with LMWH and mechanical methods (e.g. pneumatic compression stockings) are recommended perioperatively and post-operatively (e.g. 2-4 weeks). [Ref]
Long-term antiplatelet or anticoagulant therapy is not routinely recommended after splenectomy. [Ref]