The dead leukocyte content of the blood in normal and leukemic patients.

By NICHOLAS L. PET1t KIS, ESTELLE LIEBERMAN AND JEAN FULLERTON D ISINTEGRATING leukocytes are commonly seen imi blood smears and are variously designated as smudge cells, basket cells, or dead cells. Increased miunibers of these cell forms are found in leukemia and in septic states. The smudge forms are considered by some to represent the earliest stage of cell death amid to be present in the blood in variable small miumbers imi nornial conditiOnS.I . 2 Others3’ ‘ consider the smudge and basket forms to be artifacts produced by the mechanical trauma of preparimig blood smears. Quamititative data on the numbers of disintegrating leukocytes in blood smears have beemi reported by Osgood,’ who found the miormal value to be 0 to 12 per cent, averaging 5 per cent with an absolute ramige of 0 to 1200 per cu. mm. Sabin et al.’ described nonmotile leukocytes in supravital preparations of blood and believed them to be dyimig leukocytes. The purpose of the presemit study was to determimie whether or not dead leukocytes are present in the circulating blood in normal subjects and imi leukemic patients, and to study the possible relationship between the dead leukocyte numbers in whole blood and the corresponding smudge cell comitent in blood smears from the same individual. The technic of the unstained cell counts of Schrek6 . 7 was employed for this investigation. This technic readily differentiates living from dead cells by the differential permeability to weak eosin stain and introduces no significant mechanical trauma. With this method, viable cells are not stained and appear as colorless, slightly refractile spheres, whereas dead cells are freely permeable to eosin and stain pink. The validity of this technic has been confirmed by culture studies of living and dead leukocytes,8 and by metabolic criteria.9