To the Editor.—
I am surprised that Dr Greenberg,1 in republishing his earlier findings,2 failed to mention several earlier publications describing the typical occurrence of "bitten-out" red cells in drug-induced, oxidative, Heinz body hemolytic anemia. This morphologic change has been used by hematologists to screen for this disorder.3He also fails to mention a detailed study on the mechanism of phenazopyridine-induced Heinz body hemolytic anemia in non-glucose-6-phosphate dehydrogenase (G6PD)-deficient subjects,4 which describes the bitten-out red cells in this condition (p 757) as well as in vitro studies on the oxidative hemolytic potential of this compound.
Gabor EP. Heinz Body Hemolytic Anemia. Arch Intern Med. 1976;136(9):1067. doi:10.1001/archinte.1976.03630090089024