LITTLE (ARTHUR D) INC CAMBRIDGE MASS DEPT OF EXPERIMENTAL HEMATOLOGY
These studies are a continuation of those previously reported to ONR. The studies were the result of a serendipitous observation that rat or human granulocyte donors who had undergone filtration leukopheresis demonstrated a granulocytosis in spite of the removal of up to 1 x 10 to the 9th power granulocytes. Subsequent studies suggested the clinical usefulness of the use of plasma obtained from a granulocyte donor PPP to improve granulocyte yields following subsequent donations.Additional studies demonstrated that a low initial donor granulocyte level would generally portend a poor granulocyte increment during pheresis and this probably resulted from low levels of endogenous granulocytopoietins in young animals. Additionally, we have demonstrated with carefully controlled experiments the use of whole-body radioautography to show organ distribution of fresh and frozen granulocytes. A series of experiments was carried out which suggested that approximately 20,000 granulocytes per mm3 was the limit to which granulocyte mobilization in the peripheral blood could be pushed while granulocytes were simultaneously being removed in large numbers by filtration leukopheresis.