Cell quality of apheresis-derived platelets treated with riboflavin-ultraviolet light after resuspension in platelet additive solution.

BACKGROUND: Previously, we evaluated the Mirasol pathogen reduction technology (PRT) system on platelet (PLT) function before resuspension. We now evaluated this system in the presence of PLT additive solution (PAS). STUDY DESIGN AND METHODS: Double-dose PLTs (n = 15) were generated using a commercially available apheresis system (Trima, Version 5.2, CaridianBCT) allowing for the resuspension in SSP+ (MacoPharma) immediately after collection. Paired units (n = 30) were PRT treated (M) or remained untreated (C) and analyzed for metabolism (pH, pO(2) , glucose, lactate, adenosine triphosphate [ATP]), swirl, hypotonic shock response (HSR), turbidometric aggregation, CD62P expression, annexin A5 and lactate dehydrogenase (LDH) release, mitochondrial enzymatic reduction activity (MTS), transmembrane mitochondrial potential (Δψ), and surface coverage (SC) during shear-induced adhesion throughout 8 days of storage. RESULTS: As seen previously, PRT treatment of PLT units, containing a mean of 3.9 × 10(11) ± 0.3 × 10(11) PLTs in 397 ± 10 mL with a 32% to 34% plasma carryover, was associated with significantly (p < 0.001) increased cell activation, acidity, and glycolytic flux. PRT treatment appeared to up regulate both oxidative pathway and adhesional properties as evidenced by significantly higher MTS reduction, oxygen consumption, and shear-induced SC on Day 1 (p ≤ 0.016). While no significant differences were found for LDH release and ATP content (except for Day 8), M units were significantly inferior (p ≤ 0.021) for aggregation (TRAP-6); for Δψ and annexin A5 release (by Day 5); and for swirl, HSR, and MTS reduction (by Day 7). CONCLUSION: PRT treatment in the presence of PAS was comparable to PRT treatment before resuspension preserving ATP content and mitochondrial function.

Platelet derived cytokine accumulation in platelet concentrates treated for pathogen reduction.

BACKGROUND: Pathogen reduction technologies (PRTs) prevent replication and proliferation of pathogens in platelet (PLT) concentrates (PCs) by modifying nucleic acids. Due to increased cell activation, PRT may also lead to increased cytokine release from α granules and promote adverse transfusion reactions in the recipient. DESIGN: Fifteen double-dose leukoreduced apheresis PCs were collected on the Trima Accel platform (vs. 5.2.) allowing for the resuspension in PLT additive solution (PAS) immediately after collection. After a 2-h resting period (1st hour without, 2nd hour with agitation), splitting was performed: one unit remained untreated to serve as control (C), while the other was riboflavin-UVB treated using the Mirasol-PRT system according to the manufacturer's instructions (M). During 8 days of storage, PCs were analyzed for contaminating white and red blood cells, bacterial growth, PLT activation, LDH and cytokine release (MIP-1 α, RANTES, PF4, and TGF-ß-1). Results obtained were opposed to a former study, where triple-dose PCs underwent Mirasol-PRT prior to resuspension or the INTERCEPT BLOOD SYSTEM (psoralen-UVA) or remained untreated. RESULTS: Despite similar LDH release, PRT treatment was associated with significantly higher (p<0.05) cell activation but only slightly higher cytokine accumulation during storage. Differences became significant only for PF4 and RANTES at day 8 of storage. On the other hand, in the investigation on triple-dose PCs (yielding higher cytokine levels), TGF beta-1 and RANTES remained significantly (p<0.05) lower after PRT treatment compared to untreated units. CONCLUSION: Factors, such as collection modality, onset of resuspension and additional amounts of magnesium/potassium in the PAS used may be of equal or even greater impact for cytokine accumulation in stored PCs than PRT treatment.