Storage Characteristics of Split Double-Dose Platelet Concentrates Derived from Apheresis and Treated with Amotosalen Hydrochloride and UVA Light for Pathogen Inactivation

Background: By inhibiting nucleic acids, photochemical treatment (PCT) using amotosalen hydrochloride (S-59) in combination with UVA light provides a new method for the inactivation of pathogens and leukocytes, potential contaminants of platelet concentrates (PCs). Material and Methods: We evaluated the effect of PCT on function and viability of PCs derived from apheresis over a storage period of 5 days. Double-dose PCs containing 6.5–7.0 × 1011 platelets (n = 8) were collected in 600 ml of approximately 35% autologous plasma and 65% platelet additive solution. Each collection was split into two equal-sized portions for paired analysis. One day after collection, test PCs were mixed with 15 ml of 3 mmol/l S-59 and illuminated with UVA light for 3 min, followed by a 6- to 8-hour incubation in a compound adsorption device (CAD) for the reduction of residual S-59 and unbound photoproducts. In vitro platelet function measurements included platelet count, pH, lactate dehydrogenase (LDH), β-thromboglobulin (β-TG), hypotonic shock response (HSR), extent of shape change (ESC) and the expression of p-selectin. Platelet morphology and ultrastructure were analyzed by light and electron microscopy (EM). Results: We found no statistically significant differences on day 5 of the storage between the control and test platelets for pH, platelet count, p-selectin, ESC, HSR, morphology, and the percentage of lysed platelets analyzed by EM. The level of β-TG was reduced in the test units by the CAD step. Significant differences (p Conclusion: These in vitro results indicate that PCT with amotosalen and UVA light is applicable for split double-dose platelets derived from apheresis as it leads only to a transient activation of platelets immediately after the procedure, without affecting the function and structure of PCs over the 5-day storage period.