Six percent high molecular weight hydroxyethyl starch (HES) was used in the standard 500 ml dose and in various decreased doses to assess the efficacy of alternate dosage reghmens for granulocyte procurement. 10 per liter of blood processed (LBP) were obtained. When HES was used on only the first three passes, the subsequent three passes, done with Anticoagulant Citrate Dextrose Solution USP Fofvula A (ACD-A); Fenwal Laboratories, Deerfield, IL), reduced thyOyield to 0.14 + .06 x 10 /LBP. Reversing fbis procedure gave yields of 0.06 5 .05 x 10 (withzut HES) and 0.49 2 0.36 x 10 /LBP when HES was added during the next three passes.
When the HES dose was reduced to half-strength on the second consecutivpOday of leukfaheresis, the granulocyte yields were reduced from 0.57
x I$ /LBP. 10 /LBP. Infusion of the entire 500 dose of HES 112 hour prior to the procedure produced low yields of 0.20 5 .12 x 10 /LBP, indicating that HES must be present during the centrifugation and separation procedure in order to enhance yields. The data suggest that alternate dosage regimens of this form of HES are not advisable and that optimal yields are produced when 500 ml of the six percent solution is used during the collection procedure.
When used in full strength, yields of 0.57: .15 x /LBP
.15 x 10 /LBP to 0.42 + .07
Use of half-strength HES on virgin donors gave yields of only 0.35 f .39 x