An Evaluation of DFP32 and Cr51 as Methods of Measuring Red Cell Life Span in Man

Abstract

DFP³² or Cr⁵¹ red cell survival studies were performed in 39 patients with hematologic disorders. In each case the erythrocyte life span was also determined using the C¹⁴-labeled glycine technic. Good agreement was found between the survival data obtained by the DFP³² and the glycine method. The red cell Cr⁵¹ T½ failed to reflect moderate shortening of red cell survival in a significant number of cases when a 25 day half-time was taken as the lower limit of normal. The occasional discrepancy between the erythrocyte life spans obtained with labeled glycine and the Cr⁵¹ halftime is probably the result of the limitations of the prevalent method of Cr⁵¹ data analysis and of the wide range of Cr⁵¹ elution rates in disease. Because of its simplicity and reliability, the DFP³² technics appears to be the method of choice for the determination of red cell survival.