Double Exponential Nature in Chromium-51 Red Blood Cell Survival Curves in Hæmoglobin E Thalassæmia and Relation with Reticulocytes

Abstract

SEVERAL cases of hæmoglobin E thalassæmia were investigated for the survival of erythrocytes using auto red blood cells labelled in vitro with chromium-51. A standard method such as that described by Mollison¹ was adopted for the present investigation with the necessary precautions. Blood samples were collected at 10 min after the injection and afterwards on 1, 2, 3 and 5 days and thereafter every third day for a few weeks. Five ml. of blood sample was measured out, the plasma removed, hæmolysed with water to the original volume, and counted in a well-type scintillation counter at the completion of the test for each subject. The specific activity was plotted semi-logarithmically against time without any correction for chromium-51 elution. A pronounced bending in the curves was observed between 2–4 days, particularly in cases of patients. Normally, erythrocyte survival curves with chromium-51 could be fitted with an exponential type of decrease at least for the first few weeks with a little depression at the beginning due to a rapid elimination at the earliest stage². Eadie³ has, however, discussed the precise nature of the survival curves.