A nurse is administering blood to a patient who has a low hemoglobin count. The patient asks how long do red blood cells live in my body? The correct response is:
A. The life span of RBC is 45 days
B. The life span of RBC is 60 days
C. The life span of RBC is 90 days
D. The life span of RBC is 120 days
Correct Answer: D. The life span of RBC is 120 days
Red blood cells have a lifespan of 120 in the body. Today, RBC population studies are performed with a label that is placed on the RBC ex vivo, making it possible to study both donor and autologous RBC.
Option A: Human red blood cells (RBC), after differentiating from erythroblasts in the bone marrow, are released into the blood and survive in the circulation for approximately 115 days. In humans and some other species, RBC normally survives in a nonrandom manner. This means that all of the RBC in an age cohort are removed by the reticuloendothelial system at about the same time.
Option B: Accurate measurement of long-term survival requires determination of the amount of remaining labeled RBC for all or most of the RBC lifespan. Optimal determination of long-term survival also requires a steady-state situation, with the important variable depending on the label used.
Option C: Only recently with the introduction of the biotin label has a method become available that allows the detection, analysis, and isolation of aging RBC and thus detailed studies of their properties.