Change of deformability and Heinz body formation in G6PD-deficient erythrocytes treated with 5-hydroxy-6-desmethylprimaquine.

Glucose-6-phosphate deficient human erythrocytes were incubated with low concentrations of 5-hydroxy-6-desmethylprimaquine, a metabolite of primaquine in animals, for up to 18 hours under sterile conditions. These erythrocytes became less deformable than untreated erythrocytes. This decrease in deformability was closely associated with the extent and time course of formation of Heinz bodies in the G6PD-deficient erythrocytes. These results support the hypothesis that the in vivo formation of low concentrations of 5H6DPQ by metabolism of primaquine could be the cause of Heinz body formation and the hemolytic anemia seen when primaquine is administered to G6PD-deficient individuals.