Storage of buffy-coat-derived platelets in additive solutions: in vitro effects on platelets stored in reformulated PAS supplied by a 20% plasma carry-over.

BACKGROUND AND OBJECTIVES: Platelet additive solutions (PAS) have been shown to be suitable for extended platelet (PLT) storage. Depending on the PAS formulation, the percentage of plasma carry-over contributes to success. Improving PLT quality by optimizing the composition of PAS may allow a reduction to be made in the amount of plasma carried over to the final unit. Reducing the proportion of plasma carried over would probably decrease transfusion of unwanted antibodies and make greater amounts of plasma available for other needs. STUDY DESIGN AND METHODS: Platelets from eight pools of 25 buffy coats were aliquoted and prepared for storage in plasma and different PAS units: InterSol and three alternate PAS named PSM1, PSM2 and PSM3. All PAS units were supplied with a 20% plasma carry-over and stored at room temperature with agitation for 9 days with in vitro testing for metabolic, cellular and activation parameters. Results During storage, PLTs stored in InterSol displayed significantly lower glucose concentration (P < 0.01), lower adenosine triphosphate levels (P < 0.01), a higher mean PLT volume (P < 0.01), a lower response to hypotonic shock response activity (P < 0.01) and a higher CD62P expression (P < 0.01) when compared with PLTs stored in plasma and PSM1-3 solutions. pH was maintained at > 6.8 (day 9) and swirling remained at the highest level (score = 2) for all units throughout storage. CONCLUSION: Our results suggest that PLTs stored in PAS with addition of magnesium, potassium and glucose (PSM2 and PSM3) and 20% plasma carry-over maintained metabolic and cellular characteristics, equivalent to PLTs stored in 100% plasma during 9 days of storage. Our results also suggest that presence of potassium in addition to magnesium or alternatively the concentration of phosphate as well as the supply of additional glucose to normal plasma levels improve in vitro data of PLTs stored in PAS.

Extended storage of whole blood before the preparation of blood components: in vitro effects on red blood cells in Erythro-Sol environment.

BACKGROUND AND OBJECTIVES: Routine procedures for extended storage of whole blood (WB) before the preparation of blood components are of interest primarily for logistical reasons. We stored red cell units in either Erythro-Sol 2 (E-Sol 2, test units, 150 ml added) or in saline-adenine-glucose-mannitol (SAG-M) (reference units, 100 ml added) that were prepared after storage of WB at room temperature for 8, 12, 16 or 19 h after blood collection. STUDY DESIGN AND METHODS: Red blood cells were stored for 42 days. We measured pH, glucose, lactate, haemolysis, red blood cell adenosine triphosphate and 2,3-diphosphoglycerate on days 1, 7, 14, 21, 28, 35 and 42. RESULTS: Haematocrits were significantly lower in E-Sol 2 than in SAG-M due to the higher volume of E-Sol 2 added compared to SAG-M. Significantly reduced levels were found in E-Sol 2 of extracellular pH (throughout storage after 8-h hold and initially after 12-, 16- or 19-h hold), of lactate (initially after 8-h hold and throughout storage after 12-, 16- or 19-h hold), and of haemolysis from day 35 in the 8-h and on day 42 in the 12-h hold group. Significantly increased levels of adenosine triphosphate were seen in E-Sol 2 after 8-h hold (from day 14) and after 12-h hold (at days 21, 35 and 42) compared to SAG-M. Significantly higher concentrations of 2,3-diphosphoglycerate were noticed primarily after 8-h hold of WB. CONCLUSION: The use of E-Sol 2 as a replacement for SAG-M does not significantly improve in vitro data after extended storage of WB at room temperature before preparation of blood components. However, after 8-h hold in vitro characteristics similar to or better than in fresh blood will be maintained for several weeks in E-Sol 2, a situation that makes E-Sol 2 superior to SAG-M when storage of WB is limited to 8 h. Some improvement was noted after 12-h hold as well.

Inactivation of a European strain of West Nile virus in single- donor platelet concentrate using the INTERCEPT blood system.

BACKGROUND AND OBJECTIVE: In order to prevent West Nile virus (WNV) contaminations by transfusion, the French National Blood Service decided to evaluate the INTERCEPT Blood System's efficiency on a European strain. MATERIALS AND METHODS: Culture supernatant of WNV was used to infect six platelets concentrates. Viral titre was determined by plaque reduction neutralization test before and after viral inactivation using the INTERCEPT Blood System. RESULTS: In all assays, the absence of plaque forming unit was observed after viral inactivation. The log reduction observed ranged between > 5.1 logs to > 5.2 logs. CONCLUSION: INTERCEPT Blood System is a commercially viral inactivation method potentially useful in order to prevent WNV transmission by blood products in France during re-emerging outbreaks.

In vitro evaluation of Haemonetics MCS+ apheresis platelet concentrates treated with photochemical pathogen inactivation following plasma volume reduction using the INTERCEPT Preparation Set.

Pathogen inactivation using the INTERCEPT Blood System requires platelet resuspension in InterSol and reduced plasma. Platelets in plasma collected on the Haemonetics MCS+ were processed on the INTERCEPT Preparation Set for plasma volume reduction and addition of InterSol. The use of the Preparation Set resulted in a mean platelet loss of 5.6 +/- 3.4%. Subsequent photochemical treatment (PCT) with amotosalen and ultraviolet A light, and 7 days of storage, resulted in acceptable changes for platelet swirling, lactate, lactate dehydrogenase (LDH), platelet factor-4 (PF4), p-selectin, glycoprotein V (GpV), pO2, pCO2, tumour necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8). All platelet units processed with the Preparation Set and PCT met European requirements for leucoreduction and pH values.

In vitro evaluation of COM.TEC apheresis platelet concentrates using a preparation set and pathogen inactivation over a storage period of five days.

The aim of the present study was to evaluate in vitro data on platelets collected by apheresis, processed on a preparation set followed by photochemical treatment (PCT). Fifteen single-donor platelet concentrates (PCs) were collected by apheresis (COM.TEC blood cell separator, Fresenius, Bad Homburg, Germany). The platelets were transferred to the preparation set and plasma was removed after centrifugation to resuspend the platelets in approximately 37% plasma and 63% platelet additive solution InterSol. PCT was done by exposing the platelets to amotosalen HCl followed by illumination with ultraviolet light. Blood cell counts and in vitro PLT function were measured up to 5 days. An average of 3.44 +/- 0.28 x 10(11) platelets were collected in a product volume of 351 +/- 21 mL. Plasma removal resulted in a mean platelet loss of 7.8%. After PCT, a progressive decrease in platelet function was observed. LDH level rose through storage (171 +/- 81 U/L) to levels approximating LDH levels observed post-collection (180 +/- 103 U/L). There was a gradual decrease of the platelets to respond to hypotonic shock response from 90 +/- 9 % post-plasma reduction to 48 +/- 16% at day 5. All PLT units met the European requirements for leukoreduction and the pH limit of 6.8 up to day 5 post-collection. The new preparation set was capable of producing platelet units meeting the requirements for PCT. Despite differences observed in in vitro platelet function parameters, PLTs at storage day 5 fit the German and European guidelines.

Implementation of the INTERCEPT Blood System for Platelets into routine blood bank manufacturing procedures: evaluation of apheresis platelets.

BACKGROUND AND OBJECTIVES: The INTERCEPT Blood System for Platelets utilizes amotosalen-HCl (S-59) in combination with ultraviolet A (UVA) light to inactivate viruses, bacteria, protozoa and leucocytes that may contaminate platelet concentrates (PCs). To facilitate implementation of this technique into routine blood bank manufacturing procedures, this study evaluated the impact of different time settings of photochemical treatment on in vitro platelet function. MATERIALS AND METHODS: Platelets derived from apheresis (6.5-7.0 x 10(11) platelets) were resuspended in 240 ml of autologous plasma and 360 ml of platelet additive solution (PAS III) and split into two equal-sized PC units. Whereas one unit was not treated, the other was treated with 150 microm amotosalen and 3 J/cm2 UVA light followed by a compound adsorption device (CAD) step for reduction of residual amotosalen and photoproducts. In a first series of experiments (arm A, n = 7), PC units were photochemically treated after an overnight storage period of 16-23 h followed by a CAD step of 4 h. In a second series (arm B, n = 8), photochemical treatment occurred after a short storage time of 4 h with a subsequent CAD step of 16 h. Platelet function was evaluated by assaying blood gas analysis, glucose and lactate concentration, lactate dehydrogenase (LDH), hypotonic shock response (HSR) and the expression of CD62p, over a period of 7 days. RESULTS: Neither of the photochemical treatment procedures showed differences for pH, pCO2, pO2, HCO3, glucose consumption or platelet activation until the end of day 7. Increased lactate values detected for the treated units of arm A at the end of the storage period were independent from the PCT time setting. CONCLUSIONS: Photochemical pathogen inactivation with different initial resting periods between 4 and 23 h, and different CAD steps of 4 and 16 h, had no influence on the platelet in vitro function during 7 days of storage.

Functional characteristics of S-59 photochemically treated platelet concentrates derived from buffy coats.

BACKGROUND: A photochemical treatment (PCT) process for inactivation of infectious pathogens and leukocytes has been developed and evaluated using single-donor platelet concentrates. This study assessed the application of PCT to platelets prepared from pooled buffy coats. In this study, in vitro functional characteristics of PCT platelets were compared to control platelets prepared from pooled buffy coats using the approved platelet-additive solution T-Sol((R)). Platelets in platelet PAS III additive solution without PCT were evaluated as well. PCT also included the use of a psoralen (S-59) reduction device (SRD). MATERIALS AND METHODS: Four types of platelet concentrates were compared: (1) platelet concentrate in plasma/T-Sol; (2) platelet concentrate in plasma/PAS III; (3) platelet concentrate in plasma/PAS III, PCT, 9 h SRD and (4) platelet concentrate in plasma/PAS III, PCT, 16 h SRD. PCT occurred on the day after whole-blood collection. In vitro assay parameters included: pH, pO(2), pCO(2), HCO(-)(3), platelet count, mean platelet volume, plasma glucose, plasma lactate, total ATP, expression of p-selectin, hypotonic shock response and electron microscopy. RESULTS: The results indicate that PCT is compatible with platelet concentrates prepared from pooled buffy coats for up to 7 days of storage. CONCLUSION: The PCT process resulted in acceptable in vitro platelet functional characteristics and is currently in clinical trials to evaluate the haemostatic efficacy of PCT platelets in thrombocytopenic patients requiring multiple platelet transfusions.

Photochemical inactivation of bacteria and HIV in buffy-coat-derived platelet concentrates under conditions that preserve in vitro platelet function.

BACKGROUND AND OBJECTIVES: A photochemical process has been tested for the inactivation of viruses and bacteria in buffy-coat derived platelet concentrates (BC PCs). MATERIALS AND METHODS: BC PCs in 35% CPD plasma and 65% platelet-additive solution (PAS III) were exposed to photochemical treatment (PCT) with 150 microM of the psoralen S-59 and a 3 J/cm(2) treatment with long-wavelength ultraviolet light (UVA, 320-400 nm). Platelet function was evaluated following PCT using a panel of in vitro assays. RESULTS: This PCT process was highly effective at inactivating gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis) and gram-negative bacteria (Enterobacter aerogenes, Pseudomonas aeruginosa, Serratia marcescens). No viable bacteria were detected following PCT and 7 days of platelet storage while bacterial growth was detected in paired untreated control BC PCs. Complete inactivation of the gram-positive Bacillus cereus was achieved only in one of two replicate experiments with BC PCs. PCT was also highly effective for inactivation of human immunodeficiency virus HIV-1 in BC PCs inoculated with approximately 10(6) tissue culture infectious doses per milliliter (TCID(50)/ml) of cell-associated HIV-1. Rapid inactivation was observed with increasing UVA doses: with 150 microM S-59 and a 1 J/cm(2) treatment of UVA, a reduction of 5.6+/-0.5 log TCID(50)/ml was achieved, and a reduction of >6.4 log TCID(50)/ml was achieved with 150 microM S-59 and a 3 J/cm(2) treatment of UVA. No physiologically relevant differences in platelet functions were found between the test and the control BC PCs during 7 days of storage. CONCLUSION: PCT with 150 microM S-59 and a 3 J/cm(2) UVA treatment does not adversely affect in vitro properties of BC PCs stored at 22 degrees C for 7 days. The PCT process inactivated bacteria and HIV-1 inoculated into the BC PCs. These results extend the earlier reported efficacy of PCT apheresis PCs to BC PCs.