In Vivo Volume and Hemoglobin Dynamics of Human Red Blood Cells

Human red blood cells (RBCs) lose ~30% of their volume and ~20% of their hemoglobin (Hb) content during their ~100-day lifespan in the bloodstream. These observations are well-documented, but the mechanisms for these volume and hemoglobin loss events are not clear. RBCs shed hemoglobin-containing ve...

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Bibliographic Details
Main Authors: Malka, Roy, Higgins, John M., Manalis, Scott R, Delgado, Francisco Feijo
Other Authors: Massachusetts Institute of Technology. Department of Biological Engineering
Format: Article
Language:en_US
Published: Public Library of Science 2014
Online Access:http://hdl.handle.net/1721.1/90976
https://orcid.org/0000-0001-5223-9433
Description
Summary:Human red blood cells (RBCs) lose ~30% of their volume and ~20% of their hemoglobin (Hb) content during their ~100-day lifespan in the bloodstream. These observations are well-documented, but the mechanisms for these volume and hemoglobin loss events are not clear. RBCs shed hemoglobin-containing vesicles during their life in the circulation, and this process is thought to dominate the changes in the RBC physical characteristics occurring during maturation. We combine theory with single-cell measurements to investigate the impact of vesiculation on the reduction in volume, Hb mass, and membrane. We show that vesicle shedding alone is sufficient to explain membrane losses but not volume or Hb losses. We use dry mass measurements of human RBCs to validate the models and to propose that additional unknown mechanisms control volume and Hb reduction and are responsible for ~90% of the observed reduction. RBC population characteristics are used in the clinic to monitor and diagnose a wide range of conditions including malnutrition, inflammation, and cancer. Quantitative characterization of cellular maturation processes may help in the early detection of clinical conditions where maturation patterns are altered.