Time to rethink haemoglobin threshold guidelines in sickle cell disease

Area of Science:

• Hematology
• Vascular Biology
• Sickle Cell Disease Pathophysiology

Background:

• Anemia is a critical factor in sickle cell disease (SCD) management, impacting complications, organ damage, and survival.
• Current disease-modifying and curative therapies aim to increase hemoglobin (Hb) levels.

Purpose of the Study:

• To discuss the rationale for the 100 g/L Hb threshold in SCD therapies.
• To explore the impact of blood viscosity on blood flow.
• To evaluate the applicability of the Hb threshold to non-transfusion SCD therapies.

Main Methods:

• Literature review and discussion of existing data.
• Analysis of the relationship between hemoglobin levels, blood viscosity, and complications.
• Evaluation of therapeutic implications for sickle cell disease.

Main Results:

• Red blood cell transfusions are associated with complications when Hb exceeds 100 g/L.
• Elevated Hb levels can increase whole-blood viscosity, potentially leading to complications.
• The 100 g/L Hb threshold's relevance to novel SCD therapies requires careful consideration.

Conclusions:

• Managing anemia in SCD is vital for preventing complications and improving outcomes.
• The 100 g/L Hb threshold, established for transfusions, needs evaluation for newer SCD therapies.
• Understanding viscosity-related risks is crucial for optimizing treatment strategies in sickle cell disease.