Increased granulocyte counts in recipients of plasma from leukapheresed rats: a dose response study.

Humoral factors are elaborated by animal and human donors during filtration leukapheresis. Plasma obtained from rats after leukapheresis (PPP) increases granulocyte yields when given to donors prior to leukapheresis. In our studies, it appears that (1) the effect of PPP is dose-related, and (2) the granulocytosis and the titer of neutrophil releasing activity are proportional to the duration of leukapheresis. On the basis of our findings, we recommend initiation of clinical studies using postleukapheresis plasma to improve granulocyte harvests and that a dose of 1.5 ml of PPP/kg appears to be a reasonable starting point.