Rheopathologic Consequence of Plasmodium vivax Rosette Formation

Area of Science:

• Parasitology
• Biophysics
• Hematology

Background:

• Malaria parasites, like Plasmodium vivax, significantly modify the biophysical properties of infected red blood cells (RBCs).
• Understanding these alterations is crucial for comprehending parasite evasion mechanisms and disease pathogenesis.

Purpose of the Study:

• To investigate the relationship between rosette formation and the membrane deformability of Plasmodium vivax-infected RBCs.
• To quantify the adhesion forces involved in rosette formation.

Main Methods:

• Measurement of the shear elastic modulus of infected and non-infected RBCs.
• Atomic force microscopy to assess adhesion forces between infected RBCs and normocytes.
• Analysis of rosette formation under physiological shear stress.

Main Results:

• Plasmodium vivax infection significantly alters RBC rheology, increasing membrane rigidity in rosette-forming infected erythrocytes compared to non-rosetting ones.
• Strong adhesion forces (mean 440 pN) were observed between normocytes and P. vivax-infected RBCs, promoting stable rosette formation.
• Rosette formation persists even under high shear flow conditions.

Conclusions:

• Altered membrane deformability and stable rosette formation in P. vivax-infected RBCs are linked.
• Rosetting may be a mechanism for sequestering P. vivax-infected schizonts in the host's microvasculature or spleen, contributing to disease progression.