Vox Sanguinis (2014) 106, 337–343 ORIGINAL PAPER © 2013 International Society of Blood Transfusion DOI: 10.1111/vox.12113 Evaluation of in vitro storage properties of apheresis platelets suspended in a bicarbonate-containing additive solution with low levels of plasma and stored with a 24-hour interruption of agitation A. Skripchenko, A. Turgeon, D. Thompson-Montgomery, H. Awatefe & S. J. Wagner American Red Cross Biomedical Services, Holland Laboratory, Rockville, MD, USA Received: 21 August 2013, revised 17 October 2013, accepted 17 October 2013, published online 12 December 2013 Background and Objectives PLT additive solutions (PAS) are useful for reducing the frequency and/or severity of plasma-associated transfusion reactions. A new PAS solution, PAS-5, containing 5% plasma, maintains in vitro PLT properties during 7-day storage. Periods with interruption of agitation (IA) ≤24 h routinely occur during PLT shipment and do not usually compromise platelet quality. The aim of the study was to evaluate the properties of PLTs stored for 7 days in 95% PAS-5/5% plasma subjected to a 24-h IA. Materials and methods Double apheresis Amicus units (n = 12) were collected using a manual PAS-5 addition to hyperconcentrated PLTs. PLT units were equally divided in two containers. Control and test PLTs were stored with continuous agita- tion at 20–24°C except for 24-h IA period for test units between days 2–3. Results During storage, levels of glucose, lactate, mitochondrial membrane potential and aggregation significantly differed in test units compared to those of control. The pH levels of test PLTs were less than those of control units with 7/12 test units having pHs <6Á2 on Day 7 compared to 1/12 control units. Morphology score, GP1ba expression, ESC values, superoxide production were also less, and activation was greater in test PLTs than those of control. All other parameters were similar between test and control units. Conclusion PLTs stored in PAS-5 solution containing 5% plasma with a 24-h IA results in marked decrements in many in vitro PLT quality parameters during 7-day storage. Key words: interruption of agitation, low plasma level, platelet additive solution, platelet quality. Introduction One of the strategies to reduce the frequency and/or severity of febrile non-haemolytic and/or allergic transfu- sion reactions is to remove plasma by washing or volume reduction [1–3]. Another strategy to limit recipient plasma exposure is to prepare PLTs with PLT additive solution (AS) [4, 5]. Several ASs were originally devel- oped to mimic plasma ionic content without plasma proteins [6]. Currently in the United States, the two PLT ASs containing 30–35% plasma have been cleared for use for up to 5 days storage [7, 8], and several experimental PLT ASs (PAS-5, M-Sol, BRS) containing glucose and bicarbonate are under development to be used with very low residual plasma levels (1–5%) [9–11]. PLTs, if sus- pended in these experimental ASs, maintain their in vitro properties for at least 7 days of storage. With increased consolidation of blood centres and labelling facilities, PLTs are shipped more frequently. During shipment, PLTs are packed into shipping contain- ers, and continuous agitation, which is required to maintain a high level of oxidative phosphorylation, is not Correspondence: Andrey Skripchenko, American Red Cross, 15601 Crabbs Branch Way, Rockville, MD 20855, USA E-mail: Andrey.Skripchenko@redcross.org 337