Morphologic studies of sickle erythrocytes by image analysis

Area of Science:

• Hematology
• Biomedical Engineering
• Cell Biology

Background:

• Sickle cell disease (SCD) involves abnormal hemoglobin leading to red blood cell deformation.
• Understanding sickle cell morphology under varying conditions is crucial for SCD research.
• Current methods for characterizing sickle cell shape have limitations.

Purpose of the Study:

• To develop and apply an automated image analysis system for detailed sickle cell morphology characterization.
• To investigate the dynamic morphological changes of sickle cells during deoxygenation-oxygenation cycles.
• To assess the influence of pH on sickle cell morphology and desickling.

Main Methods:

• Utilized light microscopy and an automated image analysis system to process sickle cell images.
• Employed circular shape factor (CSF) and elliptical shape factor (ESF) to quantify cell morphology.
• Exposed sickle cells (SS cells) to deoxygenation-oxygenation cycles at different pH levels (6.9 and 7.4).

Main Results:

• Combined CSF and ESF successfully differentiated various sickle cell shapes (non-sickled, maple leaf, elongated).
• Initially, sickled cells predominantly adopted a maple leaf shape after deoxygenation.
• With increasing deoxygenation-oxygenation cycles, cells transitioned to an elongated sickle shape.
• Desickling was less efficient at pH 6.9 compared to pH 7.4 and with more cycles.

Conclusions:

• The automated system effectively categorizes sickle cell morphology.
• Sickle cell morphology evolves from maple leaf to elongated shapes with repeated deoxygenation.
• Persistent deoxyhemoglobin S fiber bundles may hinder complete red blood cell shape recovery, especially at lower pH.