A novel method for calculating mean erythrocyte age using erythrocyte creatine.

Masashi Kameyama,Toshika Okumiya,Masafumi Koga

doi:10.18632/aging.103193

Abstract

Estimating the lifespan of erythrocytes is useful for the differential diagnosis of anemia. However, measuring the lifespan of erythrocytes was very difficult; therefore, it was seldom measured. Erythrocyte creatine (EC) decreases reflecting erythrocyte age. We developed a method to obtain mean erythrocyte age (MRBC) from EC.We reanalyzed the previously published data from 21 patients with hemolytic anemia, which included EC and the half-life of 51Cr.MRBC and loge EC showed excellent significant linearity (r = −0.9475, p < 0.001), proving that it could be treated as a mono-exponential relationship within the studied range (EC: 1.45 – 11.76 μmol/g Hb). We established an equation to obtain MRBC (days) from EC (μmol/g Hb): MRBC = −22.84loge EC + 65.83.This equation allowed calculation of MRBC based on EC which has practical applications such as the diagnosis of anemia.

Highlights

Estimating the lifespan of erythrocytes is useful for the differential diagnosis of anemia, as it is known that the erythrocyte lifespan in hemolytic patients is shortened [1]
The current study successfully established a reliable method of estimating MRBC from Erythrocyte creatine (EC) based on a creatine model (Supplement)
Fehr et al [13] divided patients into a severe hemolytic disease group and a group with milder forms of hemolysis, our model suggested that logarithm of EC may combine the two groups (Figure 3)

Summary

Introduction

Estimating the lifespan of erythrocytes is useful for the differential diagnosis of anemia, as it is known that the erythrocyte lifespan in hemolytic patients is shortened [1]. Supply of 51Cr, which is needed for measuring erythrocyte lifespan, was ceased in Japan in 2015 due to low demand. This left Japanese doctors unable to measure the erythrocyte lifespan of patients by means of 51Cr. Biotin-labeling [2, 3] is used to measure the erythrocyte lifespan, its procedure is very laborious as well, requiring aseptic labeling of the erythrocytes and repeated blood samplings. The method needed a glycation constant to be determined by another method Some indices such as reticulocyte and haptogloblin were not sensitive enough to indicate mild hemolysis. Cases with latent hemolysis were reported which showed normal reticulocyte and normal haptogloblin levels, and yet, they showed shortened erythrocyte lifespan [7,8,9]

Objectives

Methods

Results