Pathogen inactivation of double‐dose buffy‐coat platelet concentrates photochemically treated with amotosalen and UVA light: preservation of in vitro function

Abstract

Background The INTERCEPT Blood System for Platelets (PLT) utilizes amotosalen (S-59) in combination with ultraviolet A (UVA) light to inactivate viruses, bacteria, protozoa and leucocytes that may contaminate PLT concentrates. However, limited data are available on the quality of INTERCEPT-treated double-dose (DD) buffy-coat (BC) PLT units allowing a single treatment procedure to produce two pathogen-inactivated PLT units for transfusion. Study Design and MethodsThe objective of this study was to evaluate potential in vitro effects of the INTERCEPT treatment on pools of 7 BCs as compared to untreated units. Functional, phenotypic and mitochondrial properties of DD BC PLTs during storage over 7 days were studied.Results For some parameters measured, small yet significant differences were observed including PLT count (P < 0Á05), pH, pCO 2 and glucose concentration. Throughout storage, no significant differences were observed in ATP levels, ESC, HSR reactivity and CD62P expression. Similarly, no differences were observed in the expression of PAC-1, CD42b and PECAM-1 at any time-points. The mitochondrial membrane potential (MMP) determined by JC-1-labelling was well maintained until day 7 in all treated and untreated units (>90%). The release of sCD40L increased over time (P < 0Á01) in all units but without any significant differences between treated and untreated PLTs.Conclusion Our data demonstrate that photochemical pathogen inactivation of DD-BC PLT concentrates with the INTERCEPT Blood System had no influence on the PLT in vitro quality over the 7 day of storage. However, whether in vivo efficacy of INTERCEPT-treated PLTs is affected may require clinical evaluation.

Cryopreservation of buffy coat–derived platelet concentrates photochemically treated with amotosalen and UVA light

“…9 In addition, the functional quality of PCT single-and doubledose (DD) platelets obtained either from buffy coats (BCs) or apheresis donations were analyzed previously for up to 7 days of storage. [10][11][12][13] These results seem to be in line with in vivo results of PCT platelets obtained from clinical trials. [14][15][16] Because the use of PCT lowers patient safety risks upon transfusion, their use as starting material for stocks of frozen platelets would be beneficial.…”

“…Knutson and colleagues demonstrated a safety profile for PCT platelets consistent with that previously reported for conventional platelet components . In addition, the functional quality of PCT single‐ and double‐dose (DD) platelets obtained either from buffy coats (BCs) or apheresis donations were analyzed previously for up to 7 days of storage . These results seem to be in line with in vivo results of PCT platelets obtained from clinical trials …”

“…The extracellular metabolic environment was studied by use of routine blood gas equipment (ABL 800, Radiometer) including pH (at 37°C), partial pressure of carbon dioxide , partial pressure of oxygen (kPa at 37°C), glucose, lactate and bicarbonate, and the total adenosine triphosphate (ATP) concentration, a marker of anaerobic as well as aerobic energy generation, was determined with a Luminometer (Orion Microplate Luminometer, Berthold Detection Systems GmbH). Swirling was scored by visual assessment, the WBC count prefreezing was determined with a Nageotte chamber and a microscope (Zeiss, standard), all according to previously described methods …”

“…To suppress the early steps of fibrin polymerization during stimulation with thrombin, 20 μM of gly‐pro‐arg (Sigma Aldrich) were included in the incubation step. Low cytometric analyses for PAC‐1; CD62P (Beckman Coulter); a marker for activation; CD42b (Beckman); a marker of adhesive capability; and PECAM‐1 (Sigma), a representative signaling endothelial cell adhesion molecule, as well as changes in the platelet mitochondria transmembrane potential (Δψ), were all demonstrated above that of background (negative control) and performed using a FC500 cytometer (Beckman Coulter) as recently described …”

Reduction of bacteria and human immunodeficiency virus Type 1 infectivity of platelet suspension in plasma using xenon flash‐pulse light in a bench‐scale trial

“…CD62P expression on PLTs has also been shown to correlate to in vivo PLT survival . Xe flash phototreatment enhanced CD62P expression and PAC‐1 binding at a level similar to Mirasol‐treated PLTs, but dissimilar to INTERCEPT‐treated or THERAFLEX‐treated PLTs although the functionality of αIIbβ3 decreased . Interestingly, the expression of both molecules was additionally induced by ADP in the treated PLTs contrary to the Mirasol‐treated PLTs, indicating that the treatment has some kind of priming effects on the PLT activation cascade.…”