The effect of pathogen reduction technology (Mirasol) on platelet quality when treated in additive solution with low plasma carryover.

BACKGROUND AND OBJECTIVES: Pathogen reduction technologies (PRT) for platelets are now compatible with both plasma and platelet additive solutions (PAS). The aim of this study was to examine the effect of PRT on the platelet storage lesion, in the presence of PAS with low plasma carryover. MATERIALS AND METHODS: PRT-treated (Mirasol) and untreated buffy coat-derived platelet concentrates prepared in 28% plasma/PAS-IIIM were evaluated using in vitro cell quality parameters on days 1, 2, 5, and 7 post-collection. RESULTS: At day 5, there were no significant differences between control and PRT treated platelets for swirl, viability, pO(2) , pCO(2) , mean platelet volume and adenosine diphosphate-induced aggregation. PRT treatment did not affect the functional integrity of the mitochondria. However, PRT resulted in a decrease in pH and enhancement of platelet glycolysis and activation, evidenced by increased glucose consumption and lactate production rates, increased expression of CD62P, CD63, annexin V staining and increased secretion of cytokines (P < 0.05). Hypotonic shock response and aggregation in response to collagen were also significantly reduced in PRT treated platelets (P < 0.05). CONCLUSION: Despite the observed differences in platelet metabolism and activation observed following PRT treatment in PAS and low plasma carryover, the results suggest that treatment and storage of platelets in PAS is no more detrimental to platelets than treatment and storage in plasma.

Cryopreservation of buffy-coat-derived platelet concentrates in dimethyl sulfoxide and platelet additive solution.

Platelets prepared in plasma can be frozen in 6% dimethyl sulfoxide (Me(2)SO) and stored for extended periods at -80°C. The aim of this study was to reduce the plasma present in the cryopreserved product, by substituting plasma with platelet additive solution (PAS; SSP+), whilst maintaining in vitro platelet quality. Buffy coat-derived pooled leukoreduced platelet concentrates were frozen in a mixture of SSP+, plasma and 6% Me(2)SO. The platelets were concentrated, to avoid post-thaw washing, and frozen at -80°C. The cryopreserved platelet units (n=9) were rapidly thawed at 37°C, reconstituted in 50% SSP+/plasma and stored at 22°C. Platelet recovery and quality were examined 1 and 24h post-thaw and compared to the pre-freeze samples. Upon thawing, platelet recovery ranged from 60% to 80%. However, there were differences between frozen and liquid-stored platelets, including a reduction in aggregation in response to ADP and collagen; increased CD62P expression; decreased viability; increased apoptosis and some loss of mitochondrial membrane integrity. Some recovery of these parameters was detected at 24h post-thaw, indicating an extended shelf-life may be possible. The data suggests that freezing platelets in 6% Me(2)SO and additive solution produces acceptable in vitro platelet quality.