Is splenectomy effective in treating Primary Immune-mediated Anemia (PIMA)?

Splenectomy for Primary Immune-Mediated Anemia (PIMA)

Splenectomy is not recommended as a first-line treatment for Primary Immune-Mediated Anemia (PIMA), but it can be effective as a second-line therapy for patients who have failed corticosteroid treatment, with response rates of 80% initially and 66% sustained for at least 5 years. 1

Efficacy of Splenectomy in Immune-Mediated Conditions

• Splenectomy provides high initial response rates (approximately 85%) in immune thrombocytopenia (ITP), which shares immunological mechanisms with PIMA 2
• Long-term sustained responses are seen in about 60-65% of patients with ITP following splenectomy 2
• However, up to 30% of responders will relapse within 10 years after splenectomy, most commonly within the first 2 years 2, 1
• There are currently no reliable predictors to determine which patients will respond best to splenectomy 3

Treatment Algorithm for PIMA

1. First-line therapy:

   • Corticosteroids are the recommended initial treatment for immune-mediated conditions like PIMA 2
   • Longer courses of corticosteroids are preferred over shorter courses 2

2. When to consider splenectomy:

   • For patients who have failed corticosteroid therapy 2
   • Ideally after 12 months from diagnosis to allow for spontaneous or therapy-induced remissions 3
   • Before considering splenectomy, other second-line options should be evaluated 2

3. Alternative second-line options:

   • Rituximab: Achieves responses in 40% of patients at one year and 20% at 3-5 years in ITP 4
   • Thrombopoietin receptor agonists (TPO-RAs): Effective in 70-80% of ITP patients but primarily used for thrombocytopenia 2

Risks and Considerations

• Surgical complications occur in approximately 10% of patients within 30 days following splenectomy, even with laparoscopic techniques 2, 1
• Long-term risks include:
  • Increased risk of infections, particularly septicemia (3-fold higher risk) 2
  • Higher risk of thromboembolic events (4.5-fold increased risk of pulmonary embolism) 2
  • Potential increased risk of certain malignancies 2, 1
• Lifelong management to prevent sepsis is required, including vaccinations and prophylactic antibiotics 2

Patient Selection Factors

• Splenectomy may be more appropriate for:

  • Patients desiring independence from medications 2
  • Those with an active lifestyle who prefer not to require ongoing monitoring 3
  • Patients with severe disease not responding well to medical therapy 3

• Splenectomy may be less appropriate for:

  • Elderly patients who have increased surgical morbidity and lower response rates 3
  • Young children (under 15 years) 3
  • Patients with significant comorbidities (Charlson score ≥1) 5

Monitoring After Splenectomy

• Regular follow-up is essential as relapse can occur, particularly within the first 2 years 1
• No further treatment is recommended for asymptomatic patients after splenectomy who maintain adequate blood counts 2
• For patients who relapse or fail to respond to splenectomy, additional therapies such as rituximab or TPO-RAs may be considered 2