In vitro characteristics and in vivo viability of platelets contained in granulocyte-platelet apheresis concentrate.

A paired prospective study was performed to compare the in vitro storage characteristics and in vivo kinetics of platelets stored in granulocyte-platelet concentrates prepared by apheresis with platelets prepared from whole blood. Platelet and granulocyte-platelet concentrates were collected from five healthy volunteer autologous donors and stored for 16 to 18 hours at 20 to 24 degrees C with and without agitation, respectively. After storage, pH, platelet count, percent release of beta-thromboglobulin, morphologic score, and percent osmotic recovery were measured. In addition, the granulocyte-platelet concentrates were assayed for total leukocyte count, release of lysozyme, and by several in vitro tests of granulocyte function. The platelets in both products were labeled with 111In oxine and infused into the donors. The pH of both products was above 6.0 at the end of storage. The units stored as platelet concentrates compared with those stored as granulocyte-platelet concentrates showed a higher percent release of beta-thromboglobulin, 18.4 +/- 4.0 percent versus 5.9 +/- 3.2 percent (mean +/- SD), but significantly better morphologic scores, 676 +/- 21 versus 525 +/- 56, and better osmotic recovery scores, 72 +/- 10 percent versus 40 +/- 7 percent, respectively (all p less than 0.05). The platelet concentrates (compared with the granulocyte-platelet product) had significantly better in vivo recovery, 49.5 +/- 15.8 percent versus 38.9 +/- 11.5 percent, and survival, 6.1 +/- 1.3 days versus 2.4 +/- 0.4 days, respectively (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)