Improved maintenance of platelet in vivo viability during storage when using a synthetic medium with inhibitors.

We report on the storage of platelet concentrates and the effects on in vivo and in vitro platelet function tests of adding the platelet inhibitors prostaglandin E1 and theophylline to a plasma-free synthetic medium and storage in containers with reduced surface-to-volume ratio. Paired in vivo studies on platelets labeled with indium 111 after 14-day storage demonstrated higher recoveries (mean +/- SD) of 23% +/- 9% and longer survivals of 109 +/- 59 hours for the test group versus 8% +/- 10% and 19 +/- 22 hours, respectively (p less than 0.01), for the control group (synthetic medium with no inhibitors and use of standard containers). The improved viability was associated with a significantly lower glycolytic rate; better maintenance of other in vitro parameters including respiratory activity, adenosine triphosphate levels, hypotonic shock response, surface glycoprotein Ib (by flow cytometry); and improved preservation of morphologic integrity (p less than 0.05). In particular, a strong inverse correlation (r = -0.91) was observed between in vivo recoveries and the fraction of platelets negative for glycoprotein Ib. We conclude that avoidance of platelet activation by a combination of inhibitors, plasma removal, and reduced container surface improves platelet respiratory activity, adenosine triphosphate and glycoprotein Ib levels, and posttransfusion viability of platelet concentrates stored for 14 days.