H. Isola

Preserved functional and biochemical characteristics of platelet components prepared with amotosalen and ultraviolet A for pathogen inactivation

Platelet concentrate (PC) functionality decreases during storage. This is referred to as the storage lesion. Pathogen inactivation may accelerate or induce lesions, potentially accounting for reduced viability. Our aim was to characterize functional and biochemical properties of platelets (PLTs) from photochemically treated buffy‐coat PCs (PCT‐PCs) compared to those from conventional PCs.

In vitro evaluation of pooled buffy coat platelets treated with photochemical pathogen inactivation using amotosalen

Recent studies by van Rhenen et al. found that platelets treated with amotosalen hydrochloride and ultraviolet A (UVA) illumination (INTERCEPT Blood System; Baxter Healthcare, Deerfield, IL, USA) are therapeutically equivalent to conventional (untreated) platelets currently in use [1]. Such treatment inactivates a broad spectrum of transfusiontransmitted viruses, bacteria and parasites, as well as residual donor leucocytes. Prior to the implementation of this process for all platelet units, the EFS-Alsace blood centre in Strasbourg, France, undertook a series of validation studies. The objective of our study was to provide in vitro data on the quality of buffy-coat platelet concentrates (PCs) that were treated with amotosalen and UVA. Treated PCs were studied for a period of 8 days. In accordance with standard site procedures, PCs (n = 35) were prepared from pools of six BC units suspended in InterSol platelet additive solution (65%) and plasma (35%) prior to treatment with amotosalen and UVA. Treated PCs were stored at 22 ± 2 °C. PC parameters (mean ± standard deviation) were measured, in vitro, both before treatment on day 1 and after treatment on days 2, 5, 7 and 8 of storage, as reported in Table 1. The platelet yield before treatment was 4·5 ± 0·5 × 1011. As expected, following processing, significant differences were recorded in pH, lactate, lactate dehydrogenase (LDH), platelet factor 4 (PF4), soluble p-selectin, soluble platelet glycoprotein V (GpV), mean platelet volume, O2 partial pressure (pO2) and interleukin-8 (IL-8). Non-significant differences were observed in platelet swirling, CO2 partial pressure (pCO2) and tumour necrosis factor-α (TNF-α). On day 8, significant differences were observed in pH, lactate, LDH, PF4, soluble p-selectin, soluble GpV, mean platelet volume, pCO2 and TNF-α. Non-significant differences were observed in pO2 and IL-8. Platelet swirling was maintained for 8 days. The in vitro parameters showed normal metabolism and ageing of platelets for up to 8 days after treatment with amotosalen and UVA. From this, we conclude that such treatment is fully compatible with blood centre processing laboratory protocols, and can be used routinely in clinical practice to

Évolution des techniques de préparation des produits sanguins labiles (PSL): inactivation des pathogènes dans les PSL

n Résumén n Les techniques d’inactivation des agents pathogènes dans les produits sanguins labiles (PSL) apparaissent comme la nouvelle stratégie permettant d’augmenter la sécurité transfusionnelle face aux risques de transmission d’agents pathogènes par les PSL. Différentes techniques sont en cours de développement ou déjà validées et utilisées en France. Ces dernières ne s’appliquent que pour le plasma ou les concentrés plaquettaires. Les mécanismes d’action ainsi que l’efficacité d’inactivation et d’atténuation des agents pathogènes varient en fonction des différentes techniques. Chacune d’elles constitue un procédé de préparation composé d’opérations unitaires dont il faut s’assurer de la maîtrise dans le but de garantir la qualité et l’efficacité transfusionnelle du produit traité.n n n Abstractn n The techniques for inactivation of pathogens in labile blood products (LBP) would appear to be the new strategy which will permit us to increase transfusion safety in the face of the risks of transmission of pathogenic agents by LBP. Various methods are in the course of development or already validated and used in France. The latter only apply however to plasma or platelet concentrates. The mechanisms of action and the efficacy of inactivation and attenuation of pathogenic agents vary with the different techniques. Each of these constitutes a preparative procedure composed of unit steps which have to be fully mastered in order to ensure the quality and transfusion efficacy of the treated product.n n

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‐α (TNF‐α) and interleukin‐8 (IL‐8). All platelet units processed with the Preparation Set and PCT met European requirements for leucoreduction and pH values.

Effect of L-carnitine during storage of buffy-coat platelet concentrates in an additive solution.

Platelet storage lesions correspond to defects affecting the structure and function of platelets, including their metabolic activity. During storage, the oxidation of long-chain fatty acids is impaired, leading to an increase in glucose consumption, production of lactate and a decrease in pH. L -carnitine is a small compound (molecular weight 162 Da) that plays a key role in the transport of long-chain fatty acids across the mitochondrial membrane. Previous studies have shown that the addition of L -carnitine to the storage medium improves the quality of red cells conserved in an additive solution or of platelets conserved in plasma [1–3]. In this study, we investigated the effect of L -carnitine on the quality of platelets stored in an additive solution. Whole blood (460 ml) was collected from random donors into top-and-bottom bags containing 63 ml of CPD (PL146; Baxter, La Châtre, France) and stored overnight at 20 ° C. The whole-blood units were then separated into components by high-speed centrifugation (5300 g , 15 min, 20 ° C) and placed in an automated extractor system for collection of red blood cells and plasma, leaving the buffy coats (BCs) in the collection bags (Optipress II; Baxter). Buffy-coat platelet concentrates (BPCs) were prepared from five ABO-identical BCs diluted with 280 ml of plasma ( n = 5), platelet additive solution (sodium chloride 110 m M , potassium chloride 5 m M , sodium citrate 15 m M , magnesium chloride 3 m M , sodium phosphate 25 m M , no acetate, pH 7·2; Hemosystem, Marseille, France) ( n = 5) or Lifesol® (the same additive solution containing 7 m M

In vitro quality of amotosalen-UVA pathogen-inactivated mini-pool plasma prepared from whole blood stored overnight

Small batch‐pooled (mini‐pool) whole blood (WB)‐derived plasma could be an alternative cost‐effective source of therapeutic plasma (TP), but carries an increased risk of transfusion‐transmitted infection due to exposure of the recipient to several donors. This risk can be mitigated by inactivation of pathogens susceptible to the amotosalen‐UVA (AUVA)‐treatment. We evaluated the conservation of coagulation factors in AUVA‐plasma prepared from WB stored overnight under routine operating conditions, to determine its therapeutic efficacy. Thrombin generation (TG) by the AUVA‐plasma was used to provide an integrated measure of the hemostatic capacity.

Traitement photochimique d’un mélange de plasmas issus de sang total et congélation dans un délai de 18 à 19 heures après le prélèvement

Le procede de traitement INTERCEPT Blood System (CErus) utilisant l’amotosalen et les rayons UVA a ete mis au point pour l’inactivation d’agents pathogenes dans les plaquettes et le plasma. Le plasma d’apherese traite et congele dans les 18xa0h (PFC-IA) est utilise en France. L’objectif de cette etude etait d’evaluer la qualite de melanges de plasmas issus de sang total traites par amotosalen et congeles dans les 18xa0a 19xa0h suivant la collecte. Methodes Cinq plasmas issus de sang total isogroupe ABO sont melanges, puis divises en 2xa0sous-unites de 650xa0mL pour etre traitees chacune par le procede d’inactivation des pathogenes, generant ainsi 2xa0×xa03xa0unites de 200xa0mL de plasmas frais congeles. Les 2xa0sites ont ainsi prepare 40xa0melanges de 5xa0plasmas (10xa0O, 30xa0non-O). La qualite du plasma est evaluee avant traitement (T1), puis apres 2xa0semaines (T2), 6xa0mois (T3) et 12xa0mois (T4) de conservation a −25xa0°C sur les parametres biologiques definis dans l’«xa0avis aux demandeursxa0» de l’ANSM. Resultats L’evolution des parametres biologiques pendant la conservation est detaillee dans le tableau 1. les taux de recuperation post-traitement varient de 81xa0% a 95xa0% et est egal a 68xa0% pour le facteurxa0VIII. Ces parametres demeurent stables pendant la conservation. Les plasmas sont conformes a 12xa0mois pour le facteurxa0VIII et le fibrinogene avec respectivement 77xa0% des unitesxa0≥xa0a 0,5xa0UI/mL et 90xa0% des unitesxa0>xa02xa0g/L (nxa0=xa030xa0; 33xa0% de Oxa0; ≥xa070xa0% requis). Conclusion Le melange de plasma issu de sang total traite par la methode INTERCEPT presente une qualite biochimique qui repond aux normes de qualite du plasma therapeutique inactive.

Test de génération de thrombine après traitement photochimique et conservation de plasma dérivé de sang total

Le procede INTERCEPT Blood System (Cerus), utilisant de l’amotosalen et des UVA a ete mis au point pour l’inactivation d’agents pathogenes dans les plaquettes et le plasma. La qualite de melanges de plasma issus de sang total traites a ete evaluee avec le test de generation de thrombine (TGT). Il permet de mesurer, en continu, la concentration de thrombine active et non seulement le temps necessaire a la generation des premieres traces comme dans les tests de coagulation classiques. Methodes Cinq plasmas deleucocytes issus de sang total de meme groupe ABO sont melanges puis divises en 2xa0sous-unites de 650xa0mL traitees par le procede INTERCEPT. Les 2xa0sites ont prepare 40xa0melanges donnant chacun apres traitement 2xa0×xa03xa0unitesxa0>xa0200xa0mL congelees dans les 19xa0h. Vingt-huit parametres sont mesures dont le fibrinogene, les facteurs V, VII, VIII, les TQ et TCA et le TGT a 1xa0et 20xa0pM de facteur tissulaire avant traitement (T 1 ), puis apres 2xa0semaines (T 2 ), 6xa0mois (T 3 ) et 12xa0mois (T 4 ) axa0 Resultats Bien que l’on observe ( Tableau 1 ) une baisse des facteurs de coagulation liee au traitement de respectivement 14xa0%, 9xa0%, 24xa0% et 32xa0% pour les facteurs I, V, VII, VIII et un allongement des TQ et TCA de 18xa0% et 10xa0%, aucun des parametres du TGT n’est modifie de maniere marquante avec le traitement pour la concentration de 20xa0pM de FT. La cinetique de la reaction est affectee a la concentration de FT de 1xa0pM sans influence sur la quantite totale de thrombine generee. Les parametres evoluent peu avec la conservation a −25xa0°C. Conclusion Le traitement photochimique n’affecte pas de maniere substantielle le potentiel hemostatique du plasma qui reste intact ou peu modifie egalement apres conservation.