Platelet activation and residual activation potential during storage of hyperconcentrated platelet products in two different platelet additive solutions


Annette Vetlesen, MT, Department of Immunology and Transfusion Medicine, Ullevål University Hospital, Kirkeveien 166, N-0407 Oslo, Norway; e-mail:


BACKGROUND: To improve platelet (PLT) quality, hyperconcentrated PLT concentrates (hcPCs) were compared to standard PLT concentrates (stdPCs) in two different PLT additive solutions, T-Sol and PAS-27a. PAS-27a differs from T-Sol by containing glucose, phosphate, potassium, magnesium, and bicarbonate.

STUDY DESIGN AND METHODS: PLTs were harvested by apheresis twice from 14 donors; each unit was divided into two. Four units from each donor were produced: hcPCs, 2000 × 109 per L in T-Sol or PAS-27a; and stdPCs, 1400 × 109 per L in 65 percent T-Sol or PAS-27a and 35 percent acid citrate dextrose–plasma. On Days 1 through 4, swirling was scored and PLT count, mean PLT volume, pH, blood gas, glucose, and lactate were measured. Expression of CD42a, CD62P, CD63, and PAC-1 was analyzed by flow cytometry on resting PLTs and PLTs stimulated with thrombin receptor agonist peptide (TRAP).

RESULTS: Glucose consumption and lactate production were significantly higher in hcPCs stored in PAS-27a than in T-Sol. Both stdPC and hcPC PLTs in T-Sol expressed CD62P and PAC-1 significantly higher than in PAS-27a. Over time the T-Sol hcPCs revealed highest expression of CD62P and CD63. A significantly higher capacity for up regulation of CD62P, CD63, and PAC-1 upon TRAP stimulation was found for stdPCs and hcPCs in PAS-27a compared to PLTs in T-Sol. TRAP-stimulated PLTs in stdPCs and hcPCs suspended in PAS-27a showed significantly higher potential for down regulation of CD42a than the T-Sol concentrates.

CONCLUSIONS: PLTs appear better preserved in vitro in PAS-27a than in T-Sol, and this suggests that storage of hcPCs in PAS-27a could be extended beyond 24 hours.