Blood rheology in children with the S/β+-thalassemia syndrome

Area of Science:

• Hematology
• Vascular Biology
• Pediatric Disease

Background:

• Sickle cell disease (SS) and related hemoglobinopathies (SC, S/β+-thalassemia) are characterized by abnormal red blood cells (RBCs).
• Blood rheology, including viscosity, RBC deformability, and aggregation, plays a crucial role in disease pathophysiology.
• Understanding rheological differences and their clinical correlations is vital for managing these conditions in children.

Purpose of the Study:

• To compare blood rheological parameters in children with SS, SC, S/β+-thalassemia, and healthy controls (AA).
• To investigate the association between blood rheology and clinical severity, specifically vaso-occlusive crises (VOC), in S/β+-thalassemia patients.

Main Methods:

• Blood viscosity, RBC deformability (ektacytometry), and RBC aggregation (syllectometry) were measured.
• Nitric oxide (NOx) and nitrotyrosine levels were quantified.
• Comparison between patient groups (SS, SC, S/β+-thalassemia) and healthy controls (AA).

Main Results:

• SC patients exhibited lower RBC deformability and aggregation compared to S/β+-thalassemia patients.
• Nitrotyrosine levels, a marker of oxidative stress, were lower in healthy and S/β+ individuals than in SS patients.
• S/β+-thalassemia children with a history of VOC had lower NOx and higher nitrotyrosine levels than those without VOC.

Conclusions:

• Blood rheology differs among sickle cell disease variants, with SC showing reduced RBC function compared to S/β+-thalassemia.
• Oxidative stress markers are elevated in SS disease and correlate with clinical severity in S/β+-thalassemia.
• Impaired vascular function may contribute to the severity of S/β+-thalassemia in children experiencing vaso-occlusive events.