The distribution of copper in sickling erythrocytes as determined by an IBM cell separator.

Elevated levels of copper have been found in sickling erythrocytes. Since this copper may inhibit sickling or induce hemolysis the authors decided to investigate the distribution of copper in sickling erythrocytes to gain some insight into its origin. When samples of sickling erythrocytes were fractionated by density gradient centrifugation with an IBM cell separator and the fractions analyzed for copper, it was found that the copper to hemoglobin ratio of the different fractions varied several fold. This finding indicated that the copper in sickling erythrocytes did not equilibrate with the copper in serum or other cells and that the copper was present in the cells when they were released into the blood stream. When erythrocytes were obtained from a sickle cell patient four days post-crises, a large amount of residual copper could be observed in the first (youngest) fraction. It was suspected that this copper was in mitochondrial residues. It was also observed that copper levels tended to be higher in control and sicklings erythrocytes during the winter months. The predominance of the first fraction in samples of sickling erythrocytes taken during the winter months suggests that the turnover of sickling erythrocytes is accelerated at this time.