Platelet Additive Solutions SSP+ and T-PAS+ Are Interchangeable for Platelet Concentrate Storage despite Differences in Composition and Plasticizer

Introduction: Platelet additive solutions support ex vivo storage of platelet concentrates used for transfusion. The composition of platelet additive solutions within one generation (i.e., PAS-E) is similar but not identical. Additionally, the platelet additive solution storage bag may contain different plasticizers. This study compares the effect of two PAS-E solutions (SSP+ vs. T-PAS+, stored in a DEHP-containing and DEHP-free bag, respectively) to investigate if both additive solutions are interchangeable for platelet concentrate storage. Methods: Platelet concentrates stored in plasma supplemented with SSP+ or T-PAS+ were compared by using a pool-and-split design. Platelet metabolism was investigated using a blood gas analyzer. The degree of platelet storage lesion was determined by flow cytometry to measure granule release and phosphatidylserine scrambling. Results: The quality of platelet concentrates stored in either SSP+ or T-PAS+ is acceptable as pH decreased only slightly as a function of time. PH remained above 7.2 on exiration day +1 (day 6), which is far above the minimal criterion of 6.4. Platelet storage lesion was comparable between the two study groups with only limited α-granule release and phosphatidylserine surface expression in both groups after storage for 5 days, p = 0.547 and p = 0.825, respectively. Conclusion: This study supports a safe switch between SSP+ and T-PAS+ storage solutions for platelet concentrates despite slight differences in storage solution composition and DEHP content.