Characterization of efficacy and safety of pathogen inactivated and quarantine plasma in routine use for treatment of acquired immune thrombotic thrombocytopenic purpura.

BACKGROUND: Auto-immune thrombotic thrombocytopenic purpura (TTP) is a morbid multi-organ disorder. Cardiac involvement not recognized in initial disease descriptions is a major cause of morbidity. Therapeutic plasma exchange (TPE) requires exposure to multiple plasma donors with risk of transfusion-transmitted infection (TTI). Pathogen inactivation (PI) with amotosalen-UVA, the INTERCEPT Blood System for Plasma (IBSP) is licensed to reduce TTI risk. METHODS: An open-label, retrospective study evaluated the efficacy of quarantine plasma (QP) and IBSP in TTP and defined treatment emergent cardiac abnormalities. Medical record review of sequential patient cohorts treated with QP and IBSP characterized efficacy by remission at 30 and 60 days (d) of treatment, time to remission, and volume (L/kg) of plasma required. Safety outcomes focused on cardiac adverse events (AE), relapse rates, and mortality. RESULTS: Thirty-one patients (18 IBSP and 13 QP) met study criteria for auto-immune TTP. The proportions (%) of patients in remission at 30 d (IBSP = 61·1, QP = 46·2, P = 0·570) and 60 d (IBSP = 77·8, QP = 76·9, P = 1·00) were not different. Median days to remission were less for IBSP (15·0 vs. 24·0, P = 0·003). Relapse rates (%) 60 d after remission were not different between cohorts (IBSP = 7·1, QP = 40·0, P = 0·150). ECG abnormalities before and during TPE were frequent; however, cardiac AE and mortality were not different between treatment cohorts. CONCLUSIONS: Cardiac and a spectrum of ECG findings are common in TTP. In this study, IBSP and QP had similar therapeutic profiles for TPE.

Red blood cell concentrates treated with the amustaline (S-303) pathogen reduction system and stored for 35 days retain post-transfusion viability: results of a two-centre study.

BACKGROUND AND OBJECTIVES: Pathogen reduction technology using amustaline (S-303) was developed to reduce the risk of transfusion-transmitted infection and adverse effects of residual leucocytes. In this study, the viability of red blood cells (RBCs) prepared with a second-generation process and stored for 35 days was evaluated in two different blood centres. MATERIALS AND METHODS: In a single-blind, randomized, controlled, two-period crossover study (n = 42 healthy subjects), amustaline-treated (Test) or Control RBCs were prepared in random sequence and stored for 35 days. On day 35, an aliquot of 51 Cr/99m Tc radiolabeled RBCs was transfused. In a subgroup of 26 evaluable subjects, 24-h RBC post-transfusion recovery, mean life span, median life span (T50 ) and life span area under the curve (AUC) were analysed. RESULTS: The mean 24-h post-transfusion recovery of Test and Control RBCs was comparable (83·2 ± 5·2 and 84·9 ± 5·9%, respectively; P = 0·06) and consistent with the US Food and Drug Administration (FDA) criteria for acceptable RBC viability. There were differences in the T50 between Test and Control RBCs (33·5 and 39·7 days, respectively; P < 0·001), however, these were within published reference ranges of 28-35 days. The AUC (per cent surviving × days) for Test and Control RBCs was similar (22·6 and 23·1 per cent surviving cells × days, respectively; P > 0·05). Following infusion of Test RBCs, there were no clinically relevant abnormal laboratory values or adverse events. CONCLUSION: RBCs prepared using amustaline pathogen reduction meet the FDA criteria for post-transfusion recovery and are metabolically and physiologically appropriate for transfusion following 35 days of storage.

Patient outcomes and amotosalen/UVA-treated platelet utilization in massively transfused patients.

BACKGROUND: Amotosalen/UVA-treated platelet concentrates (PCs) have demonstrated efficacy for treating and preventing bleeding in clinical trials and in routine use; however, most studies were performed in haematology/oncology patients. We investigated efficacy during massive transfusion (MT) in general hospitalized patients. METHODS: Universal amotosalen/UVA treatment (INTERCEPT Blood System) of platelets was introduced at a large Austrian medical centre. We performed a retrospective cohort analysis comparing component use, in-hospital mortality and length of stay after MT that included platelet transfusion, for two periods (21 months each) before and after implementation. RESULTS: A total of 306 patients had MT. Patients were mostly male (74%) and ≥18 years old (99%), including 93 liver transplant, 97 cardiac or vascular surgery and 51 trauma patients. There were no differences in demographics between the periods. Component use on the day and within 7 days of the MT event was unchanged post-IBS implementation, except trauma patients received fewer RBCs on the day. The mean ratio of RBC:platelets:plasma on the day of the MT was close to 1:1:1 in both periods, except for liver transplants with MT who received more plasma components. Overall, in-hospital mortality (preimplementation = 27·6% vs. postimplementation = 24·0%; P = 0·51) and median time to discharge (preimplementation = 27 vs. postimplementation = 23 days; P = 0·37) did not change, except for cardiac and vascular surgery patients who were discharged earlier. CONCLUSION: The introduction of amotosalen/UVA-treated, pathogen-reduced PC did not adversely affect clinical outcomes in massively transfused patients in terms of blood product usage, in-hospital mortality and length of stay for a range of clinical indications for platelet transfusion support.

A prospective, active haemovigilance study with combined cohort analysis of 19,175 transfusions of platelet components prepared with amotosalen-UVA photochemical treatment.

BACKGROUND AND OBJECTIVES: A photochemical treatment process (PCT) utilizing amotosalen and UVA light (INTERCEPT(™) Blood System) has been developed for inactivation of viruses, bacteria, parasites and leucocytes that can contaminate blood components intended for transfusion. The objective of this study was to further characterize the safety profile of INTERCEPT-treated platelet components (PCT-PLT) administered across a broad patient population. MATERIALS AND METHODS: This open-label, observational haemovigilance programme of PCT-PLT transfusions was conducted in 21 centres in 11 countries. All transfusions were monitored for adverse events within 24 h post-transfusion and for serious adverse events (SAEs) up to 7 days post-transfusion. All adverse events were assessed for severity (Grade 0-4), and causal relationship to PCT-PLT transfusion. RESULTS: Over the course of 7 years in the study centres, 4067 patients received 19,175 PCT-PLT transfusions. Adverse events were infrequent, and most were of Grade 1 severity. On a per-transfusion basis, 123 (0.6%) were classified an acute transfusion reaction (ATR) defined as an adverse event related to the transfusion. Among these ATRs, the most common were chills (77, 0.4%) and urticaria (41, 0.2%). Fourteen SAEs were reported, of which 2 were attributed to platelet transfusion (<0.1%). No case of transfusion-related acute lung injury, transfusion-associated graft-versus-host disease, transfusion-transmitted infection or death was attributed to the transfusion of PCT-PLT. CONCLUSION: This longitudinal haemovigilance safety programme to monitor PCT-PLT transfusions demonstrated a low rate of ATRs, and a safety profile consistent with that previously reported for conventional platelet components.

Treatment of whole blood (WB) and red blood cells (RBC) with S-303 inactivates pathogens and retains in vitro quality of stored RBC.

A pathogen inactivation (PI) process has been developed using the frangible anchor linker effector (FRALE) compound S-303. A series of experiments were performed in whole blood (WB) to measure the level of viral and bacterial inactivation. The results showed that 0.2mM S-303 and 2mM glutathione (GSH) inactivated >6.5 logs of HIV, >5.7 logs of Bluetongue virus, >7.0 logs of Yersinia enterocolitica, 4.2 logs of Serratia marcescens, and 7.5 logs of Staphylococcus epidermidis. Recent development for S-303 is focused on optimization of the PI process for red blood cell concentrates (RBC). A series of studies in RBC showed that 0.2mM S-303 and 20mM GSH inactivated approximately 5 logs or greater of Y. enterocolitica, E. coli, S. marcescens, S. aureus, HIV, bovine viral diarrhoea virus, bluetongue virus and human adenovirus 5. In both applications of the S-303 process, in vitro parameters of RBC function and physiology were retained compared to conventional RBC. Results from these studies indicate that S-303 can be applicable for PI of RBC and WB.

INTERCEPT plasma: comparability with conventional fresh-frozen plasma based on coagulation function--an in vitro analysis.

BACKGROUND: An effective pathogen inactivation (PI) technology for plasma must inactivate a broad range of pathogens with retention of haemostatic function suitable for therapeutic support. This study evaluated a broad panel of coagulation factors regarding functionality in plasma treated with the INTERCEPT Blood System (I-FFP). STUDY DESIGN AND METHODS: Apheresis plasma (600 ml) was treated with amotosalen and UVA. Aliquots of plasma were collected prior to and after photochemical treatment and frozen prior to analysis. Pro-coagulants, inhibitors and fibrinolytic proteins, contact pathway components, activation markers, the von Willebrand complex and complement proteins were analyzed. RESULTS: Retention of procoagulant factors in I-FFP ranged from 77 to 92% of pretreatment levels. Components of the von Willebrand complex, including multimers and von Willebrand cleavage protease activity (vWF:CP), remained within normal ranges after treatment. Endogenous inhibitors of coagulation were retained at 93 to 100% of baseline. Plasminogen and alpha-2 antiplasmin were retained at 94 and 78% respectively. Retention of contact factors was variable as some factors were below the reference range prior to PI treatment. With the exception of thrombin-antithrombin complexes (TAT) in one of six replicates all markers of coagulation activation were well within normal ranges. Anaphylatoxins were not increased and C1-esterase inhibitor was fully retained. CONCLUSION: Treatment of plasma with the INTERCEPT Blood System preserves proteins necessary for haemostasis without inappropriate activation of coagulation, fibrinolytic or complement pathways.

An active haemovigilance programme characterizing the safety profile of 7437 platelet transfusions prepared with amotosalen photochemical treatment.

BACKGROUND: An active haemovigilance programme was implemented to survey adverse events (AE) associated with transfusion of platelets photochemically treated with amotosalen and ultraviolet A (PCT-PLT). The results of 5106 transfusions have already been reported. Here we report the results of an additional 7437 PCT-PLT transfusions. METHODS: The focus of this ongoing haemovigilance programme is to document all AEs associated with PCT-PLT transfusion. Data collected for AEs include: time of event after starting transfusion, clinical descriptions, vital signs, results from radiographs and bacterial cultures, event severity (Grade 0-4) and causal relationship to PCT-PLT transfusion. RESULTS: One thousand four hundred patients (mean 60 years, range 1-96) received PCT-PLT transfusions. The majority of the patients (53.4%) had haematology-oncology diseases and required conventional chemotherapy (44.8%) or stem cell transplantation (8.6%). Sixty-eight PCT-PLT transfusions were associated with AE. Acute transfusion reactions (ATR), classified as an AE possibly related, probably related, or related to PCT-PLT transfusions were infrequent (n = 55, 55/7437 = 0.7%) and most were of Grade 1 severity. Thirty-nine patients (39/1400 = 2.8%) experienced one or more ATRs. The most frequently reported signs/symptoms were chills, fever, urticaria, dyspnoea, nausea and vomiting. Five AEs were considered severe (> or = Grade 2); however, no causal relationship to PCT-PLT transfusion was found. Repeated exposure to PCT-PLT did not increase the likelihood of an ATR. No cases of transfusion-related acute lung injury and no deaths due to PCT-PLT transfusions were reported. CONCLUSIONS: Routine transfusion of PCT-PLT is well-tolerated in a wide range of patients. ATRs related to PCT-PLT transfusion were infrequent and most were of mild severity.

Effect of the psoralen-based photochemical pathogen inactivation on mitochondrial DNA in platelets.

Photochemical treatment (PCT) of platelet concentrates, using amotosalen HCl and UVA-light, inactivates pathogens by forming adducts between amotosalen and nucleic acids. The impact of the photochemical treatment on pathogens and leukocytes has been studied extensively. Yet little is known about the effect of PCT on nucleic acids in platelets. Platelets contain viable mitochondria and mitochondrial DNA (mtDNA) and this study aimed at evaluating the amotosalen modifications on platelet mtDNA. We applied two independent but complementary molecular assays to investigate qualitative as well as quantitative aspects of the psoralen-mediated DNA modifications in platelet mtDNA. The amotosalen-DNA modification density was measured using (14)C-labeled amotosalen. Amotosalen (150 microM) yielded 4.0 +/- 1.2 psoralen adducts per 1,000 bp in mtDNA after irradiation with 3 J/cm(2) UVA. Furthermore, we tested if the PCT-induced DNA modifications could be detected by a PCR assay. On the basis of PCR inhibition due to amotosalen-DNA adducts, mtDNA-specific PCR assays were developed and tested for their specificity and sensitivity. Our data revealed that mtDNA in platelets is substantially modified by PCT and that these modifications can be documented by a PCR inhibition system.

Therapeutic efficacy of pooled buffy-coat platelet components prepared and stored with a platelet additive solution.

Despite the introduction of platelet additive solutions for the preparation of pooled platelet components, only a few studies of limited scope have evaluated the clinical efficacy of platelets stored in these solutions. The current report presents an analysis of data to evaluate the response to the transfusion of pooled buffy-coat components suspended in storage solution with reduced (35%) plasma content in comparison with 100% plasma products. During the euroSPRITE clinical trial of platelet components treated with a pathogen inactivation process, control treatment group platelet components were prepared in 100% allogeneic donor plasma (plasma control) or in platelet additive solution (T-Sol) mixed with plasma (T-Sol control). Control group thrombocytopenic patients received either plasma control or T-Sol control platelet components. One-hour and 24-h platelet count increments (CIs) and corrected count increments (CCIs) were analysed for these two types of preparation. In addition, haemostatic assessments were conducted for each transfusion. One-hour and 24-h mean platelet CIs and post-transfusion haemostatic scores were not significantly different for patients receiving platelet components suspended in 100% plasma and T-Sol plasma mixtures. Pooled buffy-coat platelet components prepared in reduced plasma content mixtures provided therapeutic platelet CIs with effective haemostasis.

Novel processes for inactivation of leukocytes to prevent transfusion-associated graft-versus-host disease.

Transfusion-associated graft-versus-host disease (TA-GVHD) is a serious complication of blood component transfusion therapy. Currently, cellular blood components for patients recognized at risk for TA-GVHD are irradiated prior to transfusion in order to prevent this complication. Considerable progress has been made in elucidating the pathophysiology of this highly morbid complication, but questions as to which patients are at risk and what is the most robust technology to prevent TA-GVHD remain. As new technologies for inactivating or modulating leukocyte function are introduced, the question of how to evaluate these technologies becomes relevant. Over the past two decades, a number of research groups have explored technology to inactivate infectious pathogens and leukocytes contaminating cellular blood components. Few clinicians have an in-depth understanding of the methods or the criteria for selection of how to approach new technologies for leukocyte inactivation with potential to replace current methods. This mini review focuses on the salient aspects of current and evolving technology for prevention of TA-GVHD.

Design of clinical trials to evaluate the efficacy of platelet transfusion: the euroSPRITE trial for components treated with Helinx technology.

Methods of collection, preparation, and transfusion of platelet components have evolved markedly since the introduction of modern platelet transfusion therapy three decades ago. Despite these improvements, few randomized, prospective, controlled studies have been conducted to evaluate the effects of these innovations on the outcome of platelet transfusion--prevention and treatment of bleeding due to thrombocytopenia. The majority of studies have used posttransfusion platelet count increments (CIs) as the primary outcome variable rather than bleeding assessments. In general, these studies have only examined average values for platelet CIs or adjusted ratio measures such as corrected count increment (CCI). Because platelet transfusions are given repeatedly over variable periods of time, this type of analysis has not provided information about the effects of multiple platelet transfusions or about specific product or patient-related covariates that may impact the outcome. Longitudinal regression analysis of platelet CIs offers the potential to provide more information than simple average values of ratio measures. The euroSPRITE trial, a European, multicenter, phase III study undertaken to assess the clinical efficacy and safety of platelets prepared with Helinx technology (Cerus Corp, Concord, CA), used longitudinal regression analysis to characterize more fully the response to platelet transfusions with products prepared with this new pathogen inactivation technology. In contrast to previous studies, the euroSPRITE study examined peritransfusion hemostasis and global indices of hemostasis to correlate the effect of platelet CI with prevention and treatment of bleeding during a period of platelet transfusion support.

Inactivation of infectious pathogens in labile blood components: meeting the challenge.

Substantial improvement in the safety of blood transfusion has been achieved through the addition of new tests, such as nucleic acid tests, yet residual risk associated with transfusion of blood components persists. Transfusion of blood components has been implicated in the transmission of viruses, bacteria, and protozoa. While it is commonly recognized that hepatitis B virus (HBV), hepatitis C virus (HCV), cytomegalovirus (CMV), and the retroviruses, such as human immunodeficiency virus (HIV) and the human lymphotrophic viruses (HTLV) can be transmitted through cellular components, other pathogens are emerging as potentially significant transfusion-associated infectious agents. For example, transmission of protozoan infections due to trypanosomes and babesia have been reported. In addition to viral and protozoal infectious agents, bacterial contamination of platelet and red cell concentrates continues to be reported; and may be an under-reported transfusion complication. More importantly, new infectious agents may periodically enter the donor population before they can be definitively identified and tested for to maintain consistent safety of the blood supply. The paradigm for this possibility is the HIV pandemic, which erupted in 1979. During the past decade a number of methods to inactivate infectious pathogens in labile blood components have been developed and have entered the advanced clinical trial phase.

New technologies for the inactivation of infectious pathogens in cellular blood components and the development of platelet substitutes.

Despite the increased safety of blood components, achieved through improved donor selection and testing, transfusion recipients remain at risk of transfusion-associated diseases. Transfusion of cellular blood components has been implicated in transmission of viral, bacterial and protozoan diseases. While it is commonly recognized that hepatitis B virus (HBV), hepatitis C virus (HCV), cytomegalovirus (CMV), and retroviruses, such as human immunodeficiency virus (HIV) and the human lymphotrophic viruses (HTLV), can be transmitted through cellular components, other pathogens are emerging as potentially significant transfusion-associated infectious agents. For example, transmission of protozoan infections due to trypanosomes and Babesia have been reported. In addition to viral and protozoan infectious agents, cases of bacterial contamination of platelet and red cell concentrates continue to be reported and may be an under-reported transfusion complication. More importantly, new infectious agents continue to enter the donor population, and there is an inherent time delay before the new pathogens are definitively identified and new tests implemented in order to maintain consistent safety of the blood supply. The paradigm for this problem is the HIV pandemic. During the past decade a number of methods for inactivating infectious pathogens in platelet concentrates have been investigated as a strategy to improve the safety of platelet transfusion therapy. One method of treating platelet concentrates to inactive pathogens has now reached the advanced clinical trial phase in the United States and Europe. Similar efforts with a new class of compounds are underway for red cell concentrates, and two of these are in early phase trials. In addition to studies with allogeneic platelets and red cells, a number of laboratories have described methods for developing platelet substitutes or modified platelets to avoid the use of traditional platelet concentrates as a means to improve safety.

Inactivation of viruses, bacteria, protozoa and leukocytes in platelet and red cell concentrates.

Substantial increments in the safety of blood transfusion have been achieved through continued improvements in donor testing, yet residual concern about the safety of blood components persists. To further reduce the risk of transfusion-associated infection, additional measures, such as nucleic acid testing for selected pathogens, are being introduced. Transfusion of cellular components has been implicated in transmission of viral, bacterial, and protozoan diseases [1]. While it is commonly recognized that hepatitis B virus (HBV), hepatitis C virus (HCV), cytomegalovirus (CMV), and the retroviruses, such as human immunodeficiency virus (HIV) and the human lymphotrophic viruses (HTLV) can be transmitted through cellular components, other pathogens are emerging as potentially significant transfusion-associated infectious agents. For example, transmission of protozoan infections due to trypanosomes [2-4] and babesia have been reported [5]. In addition to viral and protozoal infectious agents, bacterial contamination of platelet and red cell concentrates continues to be reported [6, 7]; and may be an under reported transfusion complication [8]. More importantly, new infectious agents may periodically enter the donor population before they can be definitively identified and tested for to maintain consistent safety of the blood supply. The paradigm for this possibility is the HIV pandemic, which erupted in 1979. During the past decade a number of methods to inactivate infectious pathogens have been developed and have entered the advanced clinical trial phase.

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.

Inactivation of viruses, bacteria, protozoa and leukocytes in platelet and red cell concentrates.

Despite the increased safety of blood achieved through continued improvements in donor testing, concern remains about the safety of blood components. Transfusion of cellular components has been implicated in transmission of viral, bacterial, and protozoan diseases [1]. While it is commonly recognized that hepatitis B virus, hepatitis C virus, cytomegalovirus, and the retroviruses, such as human immunodeficiency virus and the human lymphotrophic viruses can be transmitted through cellular components, other pathogens are emerging as potentially significant transfusion-associated infectious agents. For example, transmission of protozoan infections due to trypanosomes [2-4] and babesia [5] have been reported. In addition to viral and protozoal infectious agents, bacterial contamination of platelet and red cell concentrates continues to be reported [6, 7] and may be an under-reported transfusion complication [8]. More importantly, new infectious agents, such as HIV, may periodically enter the donor population before they can be identified. During the past decade a number of methods to inactivate infectious pathogens in blood components have been investigated. This technology is now in the clinical trial phase.