The interference of leukocytes and platelets with measurement of clucose-6-phosphate dehydrogenase activity of erythrocytes with low activity variants of the enzyme.

Complete removal of leukocytes and platelets from whole blood showed that the glucose-6-phosphage dehydrogenase (G6PD) activity in "pure" erythrocytes from G6PD deficient hemizygous Sardinian subjects is consistently lower than reported in the literature. Thus, although non of 27 hemizygous subjects showed undetectable erythrocyte G6PD activity, their levels ranged between 0.0015 and 0.008 IU/g Hb, as compared with a mean value of 4.5 IU/g Hb in normal subjects. Most of the biochemical peoperties that were formerly ascribed to erythrocyte G6PD appear to be those of the enzyme from contaminating leukocytes and (or) platelets.