Advances in the measurement of red blood cell deformability: A brief review

Red blood cells (RBCs) exhibit a unique deformability, which enables them to change shape reversibly in response to an external force. The deformability of RBCs allows them to flow in microvessels while transporting oxygen and carbon dioxide. In this review, we discussed the major determinants of RBC deformability, which include cell geometry, internal viscosity, rheological properties of the membrane, osmotic pressure, calcium, nitric oxide, temperature, ageing, and depletion of adenosine triphosphate. Additionally, we highlighted the various methods and techniques used to measure RBC deformability. Individual cell analyses (pipette aspiration and optical tweezers) and bulk cell analyses (ektacytometry, multiple channels) were described and compared. Finally, we reviewed the correlation between RBC deformability and clinical outcomes such as diabetic microangiopathy.