Variable deformability of irreversibly sickled erythrocytes

Area of Science:

• Hematology
• Cell Biology
• Biophysics

Background:

• Sickle cell disease (SCD) is characterized by abnormal red blood cells.
• Irreversibly sickled cells (ISC) contribute to SCD pathophysiology.
• Understanding ISC deformability is crucial for SCD management.

Purpose of the Study:

• To investigate the relationship between ISC deformability and their characteristics.
• To differentiate between hard and soft ISC populations.
• To identify factors influencing ISC rigidity.

Main Methods:

• Separation of ISC into hard and soft populations using Nuclepore filters.
• Measurement of erythrocyte rigidity via micropipette and Nuclepore elastimetry.
• Analysis of ISC morphology, intracellular viscosity, and surface area geometry.

Main Results:

• Significant differences in deformability and rigidity between hard and soft ISC populations were observed.
• ISC morphology, intracellular viscosity, and surface area geometry were similar in both populations.
• Intrinsic membrane alterations are suggested as the cause of differing deformability.

Conclusions:

• Intrinsic membrane alterations, not intracellular viscosity or surface geometry, dictate ISC deformability.
• Hard ISC may play a more significant role in sickle cell disease pathophysiology.
• Peripheral blood smear counts cannot distinguish between hard and soft ISC populations.