Measurement of red cell lifespan and aging

Abstract

The measurement of red blood cell (RBC) survival has a long history, and a wide variety of methods have been utilized for this purpose. Current methods are of 2 types. First, those that label a representative sample of RBCs of all ages from the blood and then measure their rate of disappearance upon reinfusion. This category includes the (51)Cr and biotin labels. Second, those that use a metabolic precursor or product to determine the turnover of hemoglobin. Examples of these are carbon monoxide production and incorporation of labeled glycine. Recent studies with the covalent, nonradioactive biotin label show its unique suitability for both the accurate measurement of red cell survival and the determination of changes in red cell properties as they age in vivo.

Keywords: Biotin; Chromium; Red cell aging; Red cell lifespan; Red cell senescence.

Fig. 1

Survival of normal RBC labeled with biotin. Six hematologically normal subjects (NDM1-NDM6) are shown. The 1-day recovery, compared to 10–20 min after reinfusion, was 96.8 ± 1.4 (1 standard deviation) %. The value at 1 day was taken as 100% for evaluation of long-term lifespan. This research was originally published in Blood in 2008 [1].

Fig. 2

RBC were labeled with biotin and reinfused into a normal subject. At the times indicated labeled cells were isolated with streptavidin-coated magnetic beads and the fraction HbA1c determined by HPLC. The mean RBC age was calculated for each time point (inverted triangles) according to [45]. The open square represents the value for TfR+ reticulocytes isolated with anti-TfR-coated magnetic beads and assayed the same way. These data indicate that the amount of HbA1c increases linearly as the RBC age. This research was originally published in Blood in 2008 [1].