G-6-PD activity of the red cells in chronic renal failure.

The G-6-PD activity of erythrocytes was studied in 75 patients with chronic renal failure and 74 normal subjects. The mean value of G-6-PD was higher in the chronic renal failure group and the difference was highly significant. During haemodialysis the G-6-PD activity did not return to normal but was further elevated, though the increase was not statistically significant. A highly significant negative correlation was found between red cell G-6-PD and haematocrit. After separation of the red cells according to age by centrifugation, G-6-PD was highest in the top (young cells) and lowest in the bottom (old) cells, both in normals and uraemic patients. The enzyme activity was higher at all levels in the uraemic subjects, significantly in the top and middle layers. Although our findings may be due to an increased proportion of young erythrocytes in uraemia there are objections to this explanation; the alternative possibility of a life-long metabolic abnormality in uraemic red cells deserves careful consideration.