Deformability of sickle cells as studied by microsieving

Area of Science:

• Hematology
• Biophysics
• Cell Biology

Background:

• Sickle cell disease (SCD) is characterized by abnormal hemoglobin (Hb SS) leading to red blood cell (RBC) rigidity.
• Altered RBC deformability contributes to vaso-occlusion and complications in SCD.

Purpose of the Study:

• To quantitatively assess the impact of deoxygenation on the deformability of sickle cells (Hb SS RBC).
• To establish a quantitative relationship between partial pressure of oxygen (P02) and Hb SS RBC deformability.

Main Methods:

• Utilized a microsieving technique with 5 µm polycarbonate filters to measure RBC filtration.
• Monitored pressure rise rate and relative resistance during filtration of Hb SS RBC suspensions at varying P02 levels.
• Conducted control experiments using normal red blood cells (Hb AA RBC).

Main Results:

• Deoxygenation below 80 mm Hg P02 progressively increased pressure rise rate and filtration resistance for Hb SS RBC.
• No significant changes in filtration parameters were observed for Hb AA RBC upon deoxygenation.
• Demonstrated a clear correlation between reduced P02 and decreased Hb SS RBC deformability.

Conclusions:

• Deoxygenation critically impairs the deformability of sickle cells (Hb SS RBC).
• The microsieving technique provides a quantitative measure of deoxygenation-induced changes in Hb SS RBC filterability.
• Findings support previous viscometric data, establishing a quantitative link between P02 and Hb SS RBC deformability.