Universal adoption of pathogen inactivation of platelet components: impact on platelet and red blood cell component use

Health Economic Aspects of Platelet Concentrates: Comparing Cost and Reimbursement of Pathogen Inactivated and Conventional Platelet Concentrates in a German Comprehensive Cancer Center

INTRODUCTION

Pathogen inactivation (PI) utilizing amotosalen and UVA light (INTERCEPT® Blood System) is a well-established method for the production of safer platelet concentrates (PCs). While many studies describe clinical and logistical benefits of PI, the implications and potential challenges from a hospital management perspective have not yet been analyzed - health economic analyses considering reimbursement of PI are lacking. The objective of this analysis was to examine the real-life inpatient treatment costs from a hospital perspective and to assess the economic impact of PI-PC versus conventional PC (CONV-PC) administration in Germany.

METHODS

Real-life cost data for inpatient cancer cases from 2020 of the University Hospital Cologne were identified by operating and procedure codes. The German diagnosis-related groups, extra fees, case mix index (CMI), length of stay (LOS), and average resource consumption of PC were evaluated from a micro-management perspective. The potential economic impact of implementing PI-treated PCs was modeled retrospectively.

RESULTS

In total, 951 inpatient cases were analyzed (CMI [median 4.7-9.9], LOS [median 26 days], number of cases in intensive care units [38%]). The median DRG fee was between EUR 13,800 and EUR 26,400. According to our model, the use of PI-PC compared to CONV-PC would result in savings between EUR 184 and EUR 306 per case.

CONCLUSION

From a hospital management perspective, oncological cases requiring PC transfusion are associated with a high CMI (reimbursement per DRG flat fee) and moderate costs with sufficient add-on payment for PI on a case level. Investment and process costs for PI implementation can be analyzed for site-specific scenarios.

Longitudinal analysis of annual national hemovigilance data to assess pathogen reduced platelet transfusion trends during conversion to routine universal clinical use and 7-day storage

BACKGROUND

France converted to universal pathogen reduced (PR; amotosalen/UVA) platelets in 2017 and extended platelet component (PC) shelf-life from 5- to 7-days in 2018 and 2019. Annual national hemovigilance (HV) reports characterized longitudinal PC utilization and safety over 11 years, including several years prior to PR adoption as the national standard of care.

METHODS

Data were extracted from published annual HV reports. Apheresis and pooled buffy coat [BC] PC use was compared. Transfusion reactions (TRs) were stratified by type, severity, and causality. Trends were assessed for three periods: Baseline (2010-14; ~7% PR), Period 1 ([P1] 2015-17; 8%-21% PR), and Period 2 ([P2] 2018-20; 100% PR).

RESULTS

PC use increased by 19.1% between 2010 and 2020. Pooled BC PC production increased from 38.8% to 68.2% of total PCs. Annual changes in PCs issued averaged 2.4% per year at baseline, -0.02% (P1) and 2.8% (P2). The increase in P2 coincided with a reduction in the target platelet dose and extension to 7-day storage. Allergic reactions, alloimmunization, febrile non-hemolytic TRs, immunologic incompatibility, and ineffective transfusions accounted for >90% of TRs. Overall, TR incidence per 100,000 PCs issued declined from 527.9 (2010) to 345.7 (2020). Severe TR rates declined 34.8% between P1-P2. Forty-six transfusion-transmitted bacterial infections (TTBI) were associated with conventional PCs during baseline and P1. No TTBI were associated with amotosalen/UVA PCs. Infections with Hepatitis E (HEV) a non-enveloped virus resistant to PR, were reported in all periods.

DISCUSSION

Longitudinal HV analysis demonstrated stable PC utilization trends with reduced patient risk during conversion to universal 7-day amotosalen/UVA PCs.

How do I implement pathogen-reduced platelets?

BACKGROUND

Several risk mitigation steps have improved the safety of platelets in regard to bacterial contamination, but this continues to be a concern today. A Food and Drug Administration (FDA) Guidance issued in December 2018 aims to further limit this risk. The guidance offers multiple pathways for compliance, and hospital blood banks will have to collaborate with blood donor centers to assess various factors before deciding which method is most appropriate for them.

METHODS AND MATERIALS

Our institution considered several factors before moving forward with pathogen reduction technology. This included an assessment of platelet shelf-life, bacterial testing requirements, the efficacy of low-yield platelets, and managing a mixed platelet inventory. The decision to transition to pathogen-reduced platelets was associated with complex collection and processing limitations that resulted in either an increase in platelets that were over-concentrated or products with a low platelet yield.

RESULTS

Through trials of various collection settings with unique target volumes and target platelet yields, our blood donor center was able to optimize the production. At the hospital end, this transition required a thorough review of low-yield platelet products and their clinical efficacy. Additionally, this implementation necessitated collaboration with clinical colleagues, comprehensive education, and training.

CONCLUSIONS

Pathogen-reduced platelets would be the most efficient way for our institution to be compliant. This summary may serve as a roadmap for other institutions that are considering which FDA prescribed method to use and provide support for those that have decided on pathogen reduction technology but need to optimize their collections to best utilize low-yield products.

Efficacy of UVC-treated, pathogen-reduced platelets versus untreated platelets: a randomized controlled non-inferiority trial

Pathogen reduction (PR) technologies for blood components have been established to reduce the residual risk of known and emerging infectious agents. THERAFLEX UV-Platelets, a novel ultraviolet C (UVC) light-based PR technology for platelet concentrates, works without photoactive substances. This randomized, controlled, double-blind, multicenter, non-inferiority trial was designed to compare the efficacy and safety of UVC-treated platelets to that of untreated platelets in thrombocytopenic patients with hematologic-oncologic diseases. The primary objective was to determine non-inferiority of UVC-treated platelets, assessed by the 1-hour corrected count increment (CCI) in up to eight per-protocol platelet transfusion episodes. Analysis of the 171 eligible patients showed that the defined non-inferiority margin of 30% of UVC-treated platelets was narrowly missed as the mean differences in 1-hour CCI between standard platelets versus UVC-treated platelets for intention-to-treat and per-protocol analyses were 18.2% (95% Confidence Interval [CI]: 6.4-30.1) and 18.7% (95% CI: 6.3-31.1), respectively. In comparison to the control, the UVC group had a 19.2% lower mean 24-hour CCI and was treated with an about 25% higher number of platelet units, but the average number of days to the next platelet transfusion did not differ significantly between both treatment groups. The frequency of low-grade adverse events was slightly higher in the UVC group and the frequencies of refractoriness to platelet transfusion, platelet alloimmunization, severe bleeding events, and red blood cell transfusions were comparable between groups. Our study suggests that transfusion of pathogen-reduced platelets produced with the UVC technology is safe but non-inferiority was not demonstrated. (clinicaltrials gov. Identifier: DRKS00011156).

Inactivation of a broad spectrum of viruses and parasites by photochemical treatment of plasma and platelets using amotosalen and ultraviolet A light

BACKGROUND

The INTERCEPT Blood System pathogen reduction technology (PRT), which uses amotosalen and ultraviolet A light treatment (amotosalen/UV-PRT), inactivates pathogens in plasma and platelet components (PCs). This review summarizes data describing the inactivation efficacy of amotosalen/UVA-PRT for a broad spectrum of viruses and parasites.

METHODS

Twenty-five enveloped viruses, six nonenveloped viruses (NEVs), and four parasites species were evaluated for sensitivity to amotosalen/UVA-PRT. Pathogens were spiked into plasma and PC at high titers. Samples were collected before and after PRT and assessed for infectivity with cell cultures or animal models. Log reduction factors (LRFs) were defined as the difference in infectious titers before and after amotosalen/UV-PRT.

RESULTS

LRFs of ≥4.0 log were reported for 19 pathogens in plasma (range, ≥4.0 to ≥7.6), 28 pathogens in PC in platelet additive solution (PC-PAS; ≥4.1-≥7.8), and 14 pathogens in PC in 100% plasma (PC-100%; (≥4.3->8.4). Twenty-five enveloped viruses and two NEVs were sensitive to amotosalen/UV-PRT; LRF ranged from >2.9 to ≥7.6 in plasma, 2.4 or greater to greater than 6.9 in PC-PAS and >3.5 to >6.5 in PC-100%. Infectious titers for four parasites were reduced by >4.0 log in all PC and plasma (≥4.9 to >8.4).

CONCLUSION

Amotosalen/UVA-PRT demonstrated effective infectious titer reduction for a broad spectrum of viruses and parasites. This confirms the capacity of this system to reduce the risk of viral and parasitic transfusion-transmitted infections by plasma and PCs in various geographies.

Trends in platelet distributions from 2008 to 2017: a survey of twelve national and regional blood collectors

BACKGROUND

This multi-national study evaluated changes in platelet (PLT) unit distributions at 12 national or regional blood collectors over a 10-year period.

METHODS

Data on the total number of PLT distributions, the collection method, that is apheresis vs whole blood-derived (WBD), the PLT unit characteristics and post-collection modifications were obtained from 12 national or regional blood collectors from 2008 through 2017. Individual WBD PLT units were converted to apheresis equivalent units (i.e. a dose of PLTs) by dividing by 4, the typical pool size; WBD units that were pooled before distribution were counted as a single dose.

RESULTS

Overall at these 12 blood collectors, the total number of PLTs distributed in 2008 was 1 373 200, which rose by 10·2% to 1 513 803 in 2017. The Japanese Red Cross, which distributes only apheresis PLTs, had a 13·4% increase in the number of distributions between the years 2008 and 2017, while the other 11 blood collectors combined demonstrated a 6·8% increase in distributions between these two years. Between the years 2008 and 2017, the changes in the proportion of apheresis, platelet-rich plasma and buffy coat PLT distributions were -29·9%, -70·7% and 80·0%, respectively.

CONCLUSION

The number of PLT distributions increased during the 10-year study period despite prophylactic PLT transfusion thresholds having remained fairly consistent over the last decade. Perhaps this increase is in part driven by increased administration of platelets to patients with massive haemorrhage or an increase in stem cell transplantation. The use of buffy coat PLTs is increasing at these collectors.

Platelets treated with pathogen reduction technology: current status and future direction

Allogeneic platelets collected for transfusion treated with pathogen reduction technology (PRT), which has been available in some countries for more than a decade, are now increasingly available in the United States (US). The implementation of PRT-treated platelets, also known as pathogen-reduced platelets (PRPs), has been spurred by the need to further decrease the risk of sepsis associated with bacterial contamination coupled with the potential of this technology to reduce the risk of infections due to already recognized, new, and emerging infectious agents. This article will review available PRP products, examine their benefits, highlight unresolved questions surrounding this technology, and summarize pivotal research studies that have compared transfusion outcomes (largely in adult patients) for PRPs with non-PRT-treated conventional platelets (CPs). In addition, studies describing the use of PRPs in pediatric patients and work done on the association between PRPs and HLA alloimmunization are discussed. As new data emerge, it is critical to re-evaluate the risks and benefits of existing PRPs and newer technologies and reassess the financial implications of adopting PRPs to guide our decision-making process for the implementation of transfusing PRPs.

Clinical impact of amotosalen-ultraviolet A pathogen-inactivated platelets stored for up to 7 days

BACKGROUND

Universal pathogen inactivation of platelet concentrates (PCs) using amotosalen/ultraviolet A with 7-day storage was implemented in Switzerland in 2011. Routine-use data were analyzed at the University Hospital Basel, Switzerland.

STUDY DESIGN

A retrospective two-cohort study of patient and PC characteristics, component usage, patient outcomes, count increments (CIs), and adverse events were analyzed for two consecutive 5-year periods with either 0- to 5-day-old conventional PC (C-PC) (n = 14,181) or 0- to 7-day-old pathogen-inactivated PC (PI-PC) (n = 22,579).

RESULTS

In both periods, PCs were issued for transfusion on a "first in, first out" basis. With 7-day PI-PC, wastage was reduced from 8.7% to 1.5%; 16.6% of transfused PI-PCs were more than 5 days old. Transfusion of PI-PC more than 5 days old compared with 5 days old or less did not increase platelet and RBC use on the same or next day as an indirect measure of hemostasis and did not increase transfusion reactions. Mean corrected count increments (CCIs) for PI-PC stored for 5 days or less were 22.6% lower than for C-PC (p < 0.001), and declined with increasing storage duration for both, although the correlation was weak (r2 = 0.005-0.014). Mean number of PCs used per patient and duration of PC support were not different for hematology/oncology, allogeneic and autologous hematopoietic stem cell transplant (HSCT), and general medical/surgical patients, who used the majority (~92.0%) of PI-PCs. Five-year treatment-related mortality in allogeneic HSCT was unchanged in the PI-PC period.

CONCLUSIONS

PI-PCs with 7-day storage reduced wastage and did not increase PC or red blood cell utilization or adverse reactions compared with fresh PI-PC or a historical control group, demonstrating preserved efficacy and safety.

The long and winding road to pathogen reduction of platelets, red blood cells and whole blood

Pathogen reduction technologies (PRTs) have been developed to further reduce the current very low risks of acquiring transfusion-transmitted infections and promptly respond to emerging infectious threats. An entire portfolio of PRTs suitable for all blood components is not available, but the field is steadily progressing. While PRTs for plasma have been used for many years, PRTs for platelets, red blood cells (RBC) and whole blood (WB) were developed more slowly, due to difficulties in preserving cell functions during storage. Two commercial platelet PRTs use ultra violet (UV) A and UVB light in the presence of amotosalen or riboflavin to inactivate pathogens' nucleic acids, while a third experimental PRT uses UVC light only. Two PRTs for WB and RBC have been tested in experimental clinical trials with storage limited to 21 or 35 days, due to unacceptably high RBC storage lesion beyond these time limits. This review summarizes pre-clinical investigations and selected outcomes from clinical trials using the above PRTs. Further studies are warranted to decrease cell storage lesions after PRT treatment and to test PRTs in different medical and surgical conditions. Affordability remains a major administrative obstacle to PRT use, particularly so in geographical regions with higher risks of transfusion-transmissible infections.

Pathogen reduction with amotosalen/UVA reduces platelet refractoriness in a dog platelet transfusion model

BACKGROUND AND OBJECTIVES

Pathogen reduction of donor platelets with amotosalen/UVA has been shown to effectively inactivate pathogens and also contaminating white blood cells (WBCs). We wanted to determine whether WBC inactivation could also decrease alloimmune refractoriness to donor platelets.

MATERIALS AND METHODS

Platelets were prepared from a donor dog's whole blood, and the platelets were either transfused without modification [standard (STD) platelets] or treated with amotosalen/UVA under conditions modelling the amotosalen/UVA Blood System for human platelets (APR) using either 4 or 3 J/cm² of UVA exposure. Platelets were transfused weekly from a single donor dog for 8 weeks or until the recipient dog became refractory to their donor's platelets. Antibody samples were drawn weekly and tested against the donor dog's platelets and WBCs (CD8 and B cells).

RESULTS

Only 1/7 (14%) dogs that received STD platelets accepted 8 weeks of donor transfusions. Following APR 4 J/cm² donor transfusions, 3/9 (33%) recipients accepted their donor's transfusions, but only one recipient remained antibody negative. Following APR 3 J/cm² donor transfusions, the same dose as used for human platelet transfusions, 7/10 (70%) recipients accepted their donor's transfusions, but only two remained antibody negative.

CONCLUSION

As a very high percentage of recipient dogs (70%) accepted APR 3 J/cm² donor transfusions, these data suggest that preventing alloimmune platelet refractoriness may be another benefit of pathogen reduction using amotosalen/UVA.

Transfusion of pathogen-reduced platelet components without leukoreduction

BACKGROUND

Leukoreduction (LR) of platelet concentrate (PC) has evolved as the standard to mitigate risks of alloimmunization, clinical refractoriness, acute transfusion reactions (ATRs), and cytomegalovirus infection, but does not prevent transfusion-associated graft-versus-host disease (TA-GVHD). Amotosalen-ultraviolet A pathogen reduction (A-PR) of PC reduces risk of transfusion-transmitted infection and TA-GVHD. In vitro data indicate that A-PR effectively inactivates WBCs and infectious pathogens.

STUDY DESIGN AND METHODS

A sequential cohort study evaluated A-PR without LR, gamma irradiation, and bacterial screening in hematopoietic stem cell transplant (HSCT) recipients. The first cohort received conventional PC (control) processed without LR, but with gamma irradiation and bacterial screening. The second cohort received A-PR PC (test) processed without: LR, bacterial screening, or gamma irradiation. The primary efficacy outcome was the 1-hour corrected count increment. The primary safety outcome was treatment-emergent ATR. Secondary outcomes included clinical refractoriness, and 100-day status for engraftment, TA-GVHD, HSCT-GVHD, infections, and mortality.

RESULTS

Mean corrected count increment (× 10³ ) of 33 test PC recipients was similar (18.9 ± 8.8 vs. 16.6 ± 8.4; p = 0.296) to that of 31 control PC recipients. Test recipients had a reduced, but nonsignificant, incidence of ATR (test = 9.1%, Control = 19.4%; p = 0.296). The frequencies of clinical refractoriness (0 of 33 vs. 4 of 31 patients) and refractory transfusions (6.6% vs. 19.3%) were lower in the test cohort (p = 0.05 and 0.02), respectively. No patient in either cohort had TA-GVHD. Day 100 engraftment, HSCT-GVHD, mortality, and infectious disease complications were similar between cohorts.

CONCLUSIONS

This study indicated that A-PR PC without LR, gamma irradiation, or bacterial screening is feasible for support of HSCT.

Economic Implications of Pathogen Reduced and Bacterially Tested Platelet Components: A US Hospital Budget Impact Model

BACKGROUND

US FDA draft guidance includes pathogen reduction (PR) or secondary rapid bacterial testing (RT) in its recommendations for mitigating risk of platelet component (PC) bacterial contamination. An interactive budget impact model was created for hospitals to use when considering these technologies.

METHODS

A Microsoft Excel model was built and populated with base-case costs and probabilities identified through literature search and a survey of US hospital transfusion service directors. Annual costs of PC acquisition, testing, wastage, dispensing/transfusion, sepsis, shelf life, and reimbursement for a mid-sized hospital that purchases all of its PCs were compared for four scenarios: 100% conventional PCs (C-PC), 100% RT-PC, 100% PR-PC, and 50% RT-PC/50% PR-PC.

RESULTS

Annual total costs were US$3.64, US$3.67, and US$3.96 million when all platelets were C-PC, RT-PC, or PR-PC, respectively, or US$3.81 million in the 50% RT-PC/50% PR-PC scenario. The annual net cost of PR-PC, obtained by subtracting annual reimbursements from annual total costs, is 6.18% above that of RT-PC. Maximum usable shelf lives for C-PC, RT-PC, and PR-PC are 3.0, 5.0, and 3.6 days, respectively; hospitals obtain PR-PC components earliest at 1.37 days.

CONCLUSION

The model predicts minimal cost increase for PR-PC versus RT-PC, including cost offsets such as elimination of bacterial detection and irradiation, and reimbursement. Additional safety provided by PR, including risk mitigation of transfusion-transmission of a broad spectrum of viruses, parasites, and emerging pathogens, may justify this increase. Effective PC shelf life may increase with RT, but platelets can be available sooner with PR due to elimination of bacterial detection, depending on blood center logistics.

Refrigeration, cryopreservation and pathogen inactivation: an updated perspective on platelet storage conditions

Conventional storage of platelet concentrates limits their shelf life to between 5 and 7 days due to the risk of bacterial proliferation and the development of the platelet storage lesion. Cold storage and cryopreservation of platelets may facilitate extension of the shelf life to weeks and years, and may also provide the benefit of being more haemostatically effective than conventionally stored platelets. Further, treatment of platelet concentrates with pathogen inactivation systems reduces bacterial contamination and provides a safeguard against the risk of emerging and re-emerging pathogens. While each of these alternative storage techniques is gaining traction individually, little work has been done to examine the effect of combining treatments in an effort to further improve product safety and minimize wastage. This review aims to discuss the benefits of alternative storage techniques and how they may be combined to alleviate the problems associated with conventional platelet storage.

Pathogen-reduced platelets for the prevention of bleeding

BACKGROUND

Platelet transfusions are used to prevent and treat bleeding in people who are thrombocytopenic. Despite improvements in donor screening and laboratory testing, a small risk of viral, bacterial, or protozoal contamination of platelets remains. There is also an ongoing risk from newly emerging blood transfusion-transmitted infections for which laboratory tests may not be available at the time of initial outbreak.One solution to reduce the risk of blood transfusion-transmitted infections from platelet transfusion is photochemical pathogen reduction, in which pathogens are either inactivated or significantly depleted in number, thereby reducing the chance of transmission. This process might offer additional benefits, including platelet shelf-life extension, and negate the requirement for gamma-irradiation of platelets. Although current pathogen-reduction technologies have been proven to reduce pathogen load in platelet concentrates, a number of published clinical studies have raised concerns about the effectiveness of pathogen-reduced platelets for post-transfusion platelet count recovery and the prevention of bleeding when compared with standard platelets.This is an update of a Cochrane review first published in 2013.

OBJECTIVES

To assess the effectiveness of pathogen-reduced platelets for the prevention of bleeding in people of any age requiring platelet transfusions.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 9), MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1950), and ongoing trial databases to 24 October 2016.

SELECTION CRITERIA

We included RCTs comparing the transfusion of pathogen-reduced platelets with standard platelets, or comparing different types of pathogen-reduced platelets.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified five new trials in this update of the review. A total of 15 trials were eligible for inclusion in this review, 12 completed trials (2075 participants) and three ongoing trials. Ten of the 12 completed trials were included in the original review. We did not identify any RCTs comparing the transfusion of one type of pathogen-reduced platelets with another.Nine trials compared Intercept® pathogen-reduced platelets to standard platelets, two trials compared Mirasol® pathogen-reduced platelets to standard platelets; and one trial compared both pathogen-reduced platelets types to standard platelets. Three RCTs were randomised cross-over trials, and nine were parallel-group trials. Of the 2075 participants enrolled in the trials, 1981 participants received at least one platelet transfusion (1662 participants in Intercept® platelet trials and 319 in Mirasol® platelet trials).One trial included children requiring cardiac surgery (16 participants) or adults requiring a liver transplant (28 participants). All of the other participants were thrombocytopenic individuals who had a haematological or oncological diagnosis. Eight trials included only adults.Four of the included studies were at low risk of bias in every domain, while the remaining eight included studies had some threats to validity.Overall, the quality of the evidence was low to high across different outcomes according to GRADE methodology.We are very uncertain as to whether pathogen-reduced platelets increase the risk of any bleeding (World Health Organization (WHO) Grade 1 to 4) (5 trials, 1085 participants; fixed-effect risk ratio (RR) 1.09, 95% confidence interval (CI) 1.02 to 1.15; I2 = 59%, random-effect RR 1.14, 95% CI 0.93 to 1.38; I2 = 59%; low-quality evidence).There was no evidence of a difference between pathogen-reduced platelets and standard platelets in the incidence of clinically significant bleeding complications (WHO Grade 2 or higher) (5 trials, 1392 participants; RR 1.10, 95% CI 0.97 to 1.25; I2 = 0%; moderate-quality evidence), and there is probably no difference in the risk of developing severe bleeding (WHO Grade 3 or higher) (6 trials, 1495 participants; RR 1.24, 95% CI 0.76 to 2.02; I2 = 32%; moderate-quality evidence).There is probably no difference between pathogen-reduced platelets and standard platelets in the incidence of all-cause mortality at 4 to 12 weeks (6 trials, 1509 participants; RR 0.81, 95% CI 0.50 to 1.29; I2 = 26%; moderate-quality evidence).There is probably no difference between pathogen-reduced platelets and standard platelets in the incidence of serious adverse events (7 trials, 1340 participants; RR 1.09, 95% CI 0.88 to 1.35; I2 = 0%; moderate-quality evidence). However, no bacterial transfusion-transmitted infections occurred in the six trials that reported this outcome.Participants who received pathogen-reduced platelet transfusions had an increased risk of developing platelet refractoriness (7 trials, 1525 participants; RR 2.94, 95% CI 2.08 to 4.16; I2 = 0%; high-quality evidence), though the definition of platelet refractoriness differed between trials.Participants who received pathogen-reduced platelet transfusions required more platelet transfusions (6 trials, 1509 participants; mean difference (MD) 1.23, 95% CI 0.86 to 1.61; I2 = 27%; high-quality evidence), and there was probably a shorter time interval between transfusions (6 trials, 1489 participants; MD -0.42, 95% CI -0.53 to -0.32; I2 = 29%; moderate-quality evidence). Participants who received pathogen-reduced platelet transfusions had a lower 24-hour corrected-count increment (7 trials, 1681 participants; MD -3.02, 95% CI -3.57 to -2.48; I2 = 15%; high-quality evidence).None of the studies reported quality of life.We did not evaluate any economic outcomes.There was evidence of subgroup differences in multiple transfusion trials between the two pathogen-reduced platelet technologies assessed in this review (Intercept® and Mirasol®) for all-cause mortality and the interval between platelet transfusions (favouring Intercept®).

AUTHORS' CONCLUSIONS

Findings from this review were based on 12 trials, and of the 1981 participants who received a platelet transfusion only 44 did not have a haematological or oncological diagnosis.In people with haematological or oncological disorders who are thrombocytopenic due to their disease or its treatment, we found high-quality evidence that pathogen-reduced platelet transfusions increase the risk of platelet refractoriness and the platelet transfusion requirement. We found moderate-quality evidence that pathogen-reduced platelet transfusions do not affect all-cause mortality, the risk of clinically significant or severe bleeding, or the risk of a serious adverse event. There was insufficient evidence for people with other diagnoses.All three ongoing trials are in adults (planned recruitment 1375 participants) with a haematological or oncological diagnosis.

Impact of platelet pathogen inactivation on blood component utilization and patient safety in a large Austrian Regional Medical Centre

BACKGROUND

In clinical studies, pathogen inactivation (PI) of platelet concentrates (PC) with amotosalen and UVA light did not impact patient risk for haemorrhage but may affect transfusion frequency and component utilization. We evaluated the influence of platelet PI on PC, red cell concentrate (RCC) and plasma use and safety in routine practice in a large regional hospital.

STUDY DESIGN AND METHODS

Comparative effectiveness of conventional vs. PI-treated PC was analysed during two 21-month periods, before and after PI implementation.

RESULTS

Similar numbers of patients were transfused in the pre-PI (control, 1797) and post-PI (test, 1694) periods with comparable numbers of PC (8611 and 7705, respectively). The mean numbers of PC per patient transfused (4·8 vs. 4·5, P = 0·43) were not different but days of PC support (5·9 vs. 5·0, P < 0·01) decreased. Most patients received RCC (86·8% control vs. 84·8% test, P = 0·90) with similar mean numbers transfused (10·8 vs. 10·2 RCC, P = 0·22), and fewer patients (55·4% control vs. 44·7% test, P < 0·01) received less plasma units (mean 9·9 vs. 7·8, respectively, P < 0·01) in the test period. The frequencies of transfusion-related adverse events (AE) were comparable (1·3% vs. 1·4%, P = 0·95). Analysis of haematology-oncology (522 control, 452 test), cardiac surgery (739 control, 711 test), paediatric (157 control, 130 test) and neonate (23 control, 20 test) patients revealed no increase in PC, plasma and RCC utilization, or AE.

CONCLUSION

Component utilization and patient safety were not impacted by adoption of PI for PC. RCC use per patient was comparable, suggestive of no increase in significant bleeding.

The role of hemovigilance and postmarketing studies when introducing innovation into transfusion medicine practice: the amotosalen-ultraviolet A pathogen reduction treatment model

BACKGROUND

Innovations in transfusion medicine require randomized controlled clinical trials (RCTs) to demonstrate safety and efficacy before approval; however, these studies are costly and limited in scope and may be underpowered to detect rare adverse events (AEs). Regulatory agencies, such as the Food and Drug Administration, require postmarketing surveillance, hemovigilance (HV), and controlled Phase IV studies to monitor performance and confirm safety.

STUDY DESIGN AND METHODS

The INTERCEPT Blood System (IBS) is an illustrative model for implementation of a transformative technology for which sponsored active HV, regulatory authority HV, and Phase IV studies were used to extend preapproval efficacy and safety information.

RESULTS

After CE mark registration in Europe, 13,644 patients received 76,346 IBS components prepared largely without gamma irradiation or bacterial screening in sponsored active HV studies documenting no increased incidence of AEs compared to historical controls and no increased component utilization. National HV systems in France and Switzerland specifically demonstrated no transfusion-associated graft-versus-host disease or increased incidence of transfusion-associated acute lung injury, after transfusion of 317,669 IBS platelet (PLT) components, and significant reduction of transfusion-transmitted bacterial infection as well as acute transfusion reactions. Cumulatively, these studies provide new information about safety and efficacy of IBS PLT and plasma components not obtainable from RCTs.

CONCLUSION

Although inherently different from RCTs, properly designed postmarketing studies are informative regarding the safety and efficacy of innovative transfusion technologies in large patient populations under conditions of routine use.

Platelet concentrates: Balancing between efficacy and safety?

Platelet transfusions continue to be the mainstay to treat patients with quantitative and qualitative platelet disorders. Each year, about 10 millions of platelet transfusions are administered to patients worldwide with marked differences in usage between regions depending on socioeconomic development of the countries. Unfortunately, its use is associated to immune and non-immune side effects. Among the non-immune, bacterial contamination is still the major infectious risk. When bacterial culture methods are introduced for preventing bacterial septic reactions it has been found that this strategy reduce to one half the septic reactions, but do not eliminate completely that risk. To remove completely the risk, a new bacteria detection test at the time of issuance in the case of platelets stored for four or five days would be needed. Pathogen inactivation (PI) methods already in the market (based in the addition of amotosalen (A-L) or riboflavin (R-L) and the illumination with ultraviolet light) or under development (ultraviolet light C and agitation) have shown to be efficacious in the inactivation of bacteria and no cases of septic reactions associated to a pathogen-reduced product has been identified. However, it has been shown that PI technologies have measurable effects on platelet in vitro parameters and reduce the recovery and survival of treated platelets in vivo. Although these effects do not hamper the hemostatic capacity of treated platelets, an increased usage associated with PI technologies has been reported. This increase in utilization seems to be the toll to be paid if we want to completely eliminate the risk of bacterial sepsis in the recipients of platelet transfusion.

Observational study of corrected count increments after transfusion of platelets treated with riboflavin pathogen reduction technology in additive solutions

BACKGROUND

Mirasol pathogen reduction technology (PRT) treatment inactivates bacteria, viruses, and parasites in plasma products and platelets (PLTs) suspended in plasma and PLT additive solutions (PAS). Few clinical studies exist documenting transfusions with PAS. This study objective was to evaluate the count increments of PRT-treated PAS-C and PAS-E buffy coat (BC) PLTs in routine use observational settings.

STUDY DESIGN AND METHODS

PLT pools of five or six BCs were collected, processed, and suspended in PAS-C or PAS-E, respectively. Products were exposed to ultraviolet light in the presence of riboflavin and then transfused into 19 patients with hematologic diseases. Patients were monitored for PLT corrected count increment (CCI) at 1 and 24 hours and for any adverse events in the 72 hours after transfusion. Sterility monitoring was performed with a microbial detection system (BacT/ALERT, bioMérieux).

RESULTS

The PAS-E products had significantly higher PLT concentrations and counts than the PAS-C products. The mean CCIs of per-protocol (PP) units at 1 and 24 hours were 11,900 (n=27) and 5500 (n=30), respectively. Seventy-eight percent of PP transfusions classify as successful with CCIs at 1 hour of higher than 7500, and 63% higher than 4500 at 24 hours. One patient was excluded from all analyses as she was refractory to Mirasol-treated PLT transfusions and follow-up untreated transfusion products. No adverse events were observed and no contaminated products were detected by BacT/ALERT.

CONCLUSION

PRT-treated BC PLTs in PAS-C or PAS-E demonstrate PLT transfusion success rates in hematology patients with thrombocytopenia that are comparable to previous studies examining PLTs stored in plasma.

In vitro evaluation of pathogen-inactivated buffy coat-derived platelet concentrates during storage: psoralen-based photochemical treatment step-by-step

BACKGROUND

The Intercept Blood SystemTM (Cerus) is used to inactivate pathogens in platelet concentrates (PC). The aim of this study was to elucidate the extent to which the Intercept treatment modifies the functional properties of platelets.

MATERIAL AND METHODS

A two-arm study was conducted initially to compare buffy coat-derived pathogen-inactivated PC to untreated PC (n=5) throughout storage. A four-arm study was then designed to evaluate the contribution of the compound adsorbing device (CAD) and ultraviolet (UV) illumination to the changes observed upon Intercept treatment. Intercept-treated PC, CAD-incubated PC, and UV-illuminated PC were compared to untreated PC (n=5). Functional characteristics were assessed using flow cytometry, hypotonic shock response (HSR), aggregation, adhesion assays and flow cytometry for the detection of CD62P, CD42b, GPIIb-IIIa, phosphatidylserine exposure and JC-1 aggregates.

RESULTS

Compared to fresh platelets, end-of-storage platelets exhibited greater passive activation, disruption of the mitochondrial transmembrane potential (Δψm), and phosphatidylserine exposure accompanied by a decreased capacity to respond to agonist-induced aggregation, lower HSR, and CD42b expression. The Intercept treatment resulted in significantly lower HSR and CD42b expression compared to controls on day 7, with no significant changes in CD62P, Δψm, or phosphatidylserine exposure. GPIIbIIIa expression was significantly increased in Intercept-treated platelets throughout the storage period. The agonist-induced aggregation response was highly dependent on the type and concentration of agonist used, indicating a minor effect of the Intercept treatment. The CAD and UV steps alone had a negligible effect on platelet aggregation.

DISCUSSION

The Intercept treatment moderately affects platelet function in vitro. CAD and UV illumination alone make negligible contributions to the changes in aggregation observed in Intercept-treated PC.

The clinical and biological impact of new pathogen inactivation technologies on platelet concentrates

Since 1990, several techniques have been developed to photochemically inactivate pathogens in platelet concentrates, potentially leading to safer transfusion therapy. The three most common methods are amotosalen/UVA (INTERCEPT Blood System), riboflavin/UVA-UVB (MIRASOL PRT), and UVC (Theraflex-UV). We review the biology of pathogen inactivation methods, present their efficacy in reducing pathogens, discuss their impact on the functional aspects of treated platelets, and review clinical studies showing the clinical efficiency of the pathogen inactivation methods and their possible toxicity.

Pathogen inactivation efficacy of Mirasol PRT System and Intercept Blood System for non-leucoreduced platelet-rich plasma-derived platelets suspended in plasma

BACKGROUND AND OBJECTIVES

This study was conducted to evaluate the efficacy of pathogen inactivation (PI) in non-leucoreduced platelet-rich plasma-derived platelets suspended in plasma using the Mirasol PRT System and the Intercept Blood System.

METHODS

Platelets were pooled using the Acrodose PL system and separated into two aliquots for Mirasol and Intercept treatment. Four replicates of each viral strain were used for the evaluation. For bacteria, both low-titre (45-152 CFU/unit) inoculation and high-titre (7·34-10·18 log CFU/unit) inoculation with two replicates for each bacterial strain were used. Platelets with non-detectable bacterial growth and platelets inoculated with a low titre were stored for 5 days, and culture was performed with the BacT/ALERT system.

RESULTS

The inactivation efficacy expressed as log reduction for Mirasol and Intercept systems for viruses was as follows: human immunodeficiency virus 1, ≥4·19 vs. ≥4·23; bovine viral diarrhoea virus, 1·83 vs. ≥6·03; pseudorabies virus, 2·73 vs. ≥5·20; hepatitis A virus, 0·62 vs. 0·76; and porcine parvovirus, 0·28 vs. 0·38. The inactivation efficacy for bacteria was as follows: Escherichia coli, 5·45 vs. ≥9·22; Staphylococcus aureus, 4·26 vs. ≥10·11; and Bacillus subtilis, 5·09 vs. ≥7·74. Postinactivation bacterial growth in platelets inoculated with a low titre of S. aureus or B. subtilis was detected only with Mirasol.

CONCLUSION

Pathogen inactivation efficacy of Intercept for enveloped viruses was found to be satisfactory. Mirasol showed satisfactory inactivation efficacy for HIV-1 only. The two selected non-enveloped viruses were not inactivated by both systems. Inactivation efficacy of Intercept was more robust for all bacteria tested at high or low titres.

Emerging Pathogens - How Safe is Blood?

During the last few decades, blood safety efforts were mainly focused on preventing viral infections. However, humanity's increased mobility and improved migration pathways necessitate a global perspective regarding other transfusion-transmitted pathogens. This review focuses on the general infection risk of blood components for malaria, dengue virus, Trypanosoma cruzi (Chagas disease) and Babesia spp. Approximately 250 million people become infected by Plasmodium spp. per year. Dengue virus affects more than 50 million people annually in more than 100 countries; clinically, it can cause serious diseases, such as dengue haemorrhagic fever and dengue shock syndrome. Chagas disease, which is caused by Trypanosoma cruzi, mainly occurs in South America and infects approximately 10 million people annually. Babesia spp. is a parasitic infection that infects red blood cells; although many infections are asymptomatic, severe clinical disease has been reported, especially in the elderly. Screening assays are available for all considered pathogens but make screening strategies more complex and more expensive. A general pathogen inactivation for all blood components (whole blood) promises to be a long-term, sustainable solution for both known and unknown pathogens. Transfusion medicine therefore eagerly awaits such a system.

Pathogen-free, plasma-poor platelet lysate and expansion of human mesenchymal stem cells

BACKGROUND

Supplements to support clinical-grade cultures of mesenchymal stem cells (MSC) are required to promote growth and expansion of these cells. Platelet lysate (PL) is a human blood component which may replace animal serum in MSC cultures being rich in various growth factors. Here, we describe a plasma poor pathogen-free platelet lysate obtained by pooling 12 platelet (PLT) units, to produce a standardized and safe supplement for clinical-grade expansion of MSC.

METHODS

PL lots were obtained by combining 2 6-unit PLT pools in additive solution (AS) following a transfusional-based procedure including pathogen inactivation (PI) by Intercept technology and 3 cycles of freezing/thawing, followed by membrane removal. Three PI-PL and 3 control PL lots were produced to compare their ability to sustain bone marrow derived MSC selection and expansion. Moreover, two further PL, subjected to PI or not, were also produced starting from the same initial PLT pools to evaluate the impact of PI on growth factor concentration and capacity to sustain cell growth. Additional PI-PL lots were used for comparison with fetal bovine serum (FBS) on MSC expansion. Immunoregulatory properties of PI-PL-generated MSC were documented in vitro by mixed lymphocyte culture (MLC) and peripheral blood mononuclear cells (PBMC) mitogen induced proliferation.

RESULTS

PI-PL and PL control lots had similar concentrations of 4 well-described growth factors endowed with MSC stimulating ability. Initial growth and MSC expansion by PI-PL and PL controls were comparable either using different MSC populations or in head to head experiments. Moreover, PI-PL and PL control sustained similar MSC growth of frozen/thawed MSC. Multilineage differentiation of PI-derived and PI-PL-derived MSC were maintained in any MSC cultures as well as their immunoregulatory properties. Finally, no direct impact of PI on growth factor concentration and MSC growth support was observed, whereas the capacity of FBS to sustain MSC expansion in basic medium was irrelevant as compared to PL and PI-PL.

CONCLUSION

The replacement of animal additives with human supplements is a basic issue in MSC ex vivo production. PI-PL represents a standardized, plasma-poor, human preparation which appears as a safe and good candidate to stimulate MSC growth in clinical-scale cultures.

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

BACKGROUND

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.

STUDY DESIGN AND METHODS

Four PCT-PCs and four conventional PCs were stored for 6.5 days and PLT function and proteomic profiles were examined at various time points during storage. To evaluate their intrinsic properties, samples of stored PLTs were taken, washed, and suspended in Tyrode's buffer before testing.

RESULTS

PLT counts and morphology were conserved although a slight increase in the PLT volume was observed after PCT. Glycoprotein (GP) IIbIIIa, IaIIa, and VI expression remained stable while GPIbα declined similarly in both types of PCs. A steep decrease (50%) in GPV occurred on Day 1.5 in PCT-PCs and Day 2.5 in control PCs. For both PCT- and control PCs, P-selectin expression and activated GPIIbIIIa remained low during storage. PCT- and control PCs were fully responsive to aggregation agonists up to Day 4.5 and exhibited similar perfusion functionality. Mitochondrial membrane potential and annexin A5 binding of PCT-PCs and control PCs were comparable. Two-dimensional differential in-gel electrophoresis and mass spectrometry profiles for 1882 protein spots revealed only three proteins selectively changed in PCT-PCs compared to control-PCs.

CONCLUSION

Washed treated and untreated PCs have similar functional, morphologic, and proteomic characteristics provided that PLTs are suspended in an appropriate medium during testing.

Update on the use of pathogen-reduced human plasma and platelet concentrates

The use of pathogen reduction technologies (PRTs) for labile blood components is slowly but steadily increasing. While pathogen-reduced plasma is already used routinely, efficacy and safety concerns impede the widespread use of pathogen-reduced platelets. The supportive and often prophylactic nature of blood component therapy in a variety of clinical situations complicates the clinical evaluation of these novel blood products. However, an increasing body of evidence on the clinical efficacy, safety, cost-benefit ratio and development of novel technologies suggests that pathogen reduction has entered a stage of maturity that could further increase the safety margin in haemotherapy. This review summarizes the clinical evidence on PRTs for plasma and platelet products that are currently licensed or under development.

Pathogen-reduced platelets for the prevention of bleeding

BACKGROUND

Platelet transfusions are used to prevent and treat bleeding in patients who are thrombocytopenic. Despite improvements in donor screening and laboratory testing, a small risk of viral, bacterial or protozoal contamination of platelets remains. There is also an ongoing risk from newly emerging blood transfusion-transmitted infections (TTIs) for which laboratory tests may not be available at the time of initial outbreak.One solution to reduce further the risk of TTIs from platelet transfusion is photochemical pathogen reduction, a process by which pathogens are either inactivated or significantly depleted in number, thereby reducing the chance of transmission. This process might offer additional benefits, including platelet shelf-life extension, and negate the requirement for gamma-irradiation of platelets. Although current pathogen-reduction technologies have been proven significantly to reduce pathogen load in platelet concentrates, a number of published clinical studies have raised concerns about the effectiveness of pathogen-reduced platelets for post-transfusion platelet recovery and the prevention of bleeding when compared with standard platelets.

OBJECTIVES

To assess the effectiveness of pathogen-reduced platelets for the prevention of bleeding in patients requiring platelet transfusions.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2013, Issue 1), MEDLINE (1950 to 18 February 2013), EMBASE (1980 to 18 February 2013), CINAHL (1982 to 18 February 2013) and the Transfusion Evidence Library (1980 to 18 February 2013). We also searched several international and ongoing trial databases and citation-tracked relevant reference lists. We requested information on possible unpublished trials from known investigators in the field.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing the transfusion of pathogen-reduced platelets with standard platelets. We did not identify any RCTs which compared the transfusion of one type of pathogen-reduced platelets with another.

DATA COLLECTION AND ANALYSIS

One author screened all references, excluding duplicates and those clearly irrelevant. Two authors then screened the remaining references, confirmed eligibility, extracted data and analysed trial quality independently. We requested and obtained a significant amount of missing data from trial authors. We performed meta-analyses where appropriate using the fixed-effect model for risk ratios (RR) or mean differences (MD), with 95% confidence intervals (95% CI), and used the I² statistic to explore heterogeneity, employing the random-effects model when I² was greater than 30%.

MAIN RESULTS

We included 10 trials comparing pathogen-reduced platelets with standard platelets. Nine trials assessed Intercept® pathogen-reduced platelets and one trial Mirasol® pathogen-reduced platelets. Two were randomised cross-over trials and the remaining eight were parallel-group RCTs. In total, 1422 participants were available for analysis across the 10 trials, of which 675 participants received Intercept® and 56 Mirasol® platelet transfusions. Four trials assessed the response to a single study platelet transfusion (all Intercept®) and six to multiple study transfusions (Intercept® (N = 5), Mirasol® (N = 1)) compared with standard platelets.We found the trials to be generally at low risk of bias but heterogeneous regarding the nature of the interventions (platelet preparation), protocols for platelet transfusion, definitions of outcomes, methods of outcome assessment and duration of follow-up.Our primary outcomes were mortality, 'any bleeding', 'clinically significant bleeding' and 'severe bleeding', and were grouped by duration of follow-up: short (up to 48 hours), medium (48 hours to seven days) or long (more than seven days). Meta-analysis of data from five trials of multiple platelet transfusions reporting 'any bleeding' over a long follow-up period found an increase in bleeding in those receiving pathogen-reduced platelets compared with standard platelets using the fixed-effect model (RR 1.09, 95% CI 1.02 to 1.15, I² = 59%); however, this meta-analysis showed no difference between treatment arms when using the random-effects model (RR 1.14, 95% CI 0.93 to 1.38).There was no evidence of a difference between treatment arms in the number of patients with 'clinically significant bleeding' (reported by four out of the same five trials) or 'severe bleeding' (reported by all five trials) (respectively, RR 1.06, 95% CI 0.93 to 1.21, I² = 2%; RR 1.27, 95% CI 0.76 to 2.12, I² = 51%). We also found no evidence of a difference between treatment arms for all-cause mortality, acute transfusion reactions, adverse events, serious adverse events and red cell transfusion requirements in the trials which reported on these outcomes. No bacterial transfusion-transmitted infections occurred in the six trials that reported this outcome.Although the definition of platelet refractoriness differed between trials, the relative risk of this event was 2.74 higher following pathogen-reduced platelet transfusion (RR 2.74, 95% CI 1.84 to 4.07, I² = 0%). Participants required 7% more platelet transfusions following pathogen-reduced platelet transfusion when compared with standard platelet transfusion (MD 0.07, 95% CI 0.03 to 0.11, I² = 21%), although the interval between platelet transfusions was only shown to be significantly shorter following multiple Intercept® pathogen-reduced platelet transfusion when compared with standard platelet transfusion (MD -0.51, 95% CI -0.66 to -0.37, I² = 0%). In trials of multiple pathogen-reduced platelets, our analyses showed the one- and 24-hour count and corrected count increments to be significantly inferior to standard platelets. However, one-hour increments were similar in trials of single platelet transfusions, although the 24-hour count and corrected count increments were again significantly lower.

AUTHORS' CONCLUSIONS

We found no evidence of a difference in mortality, 'clinically significant' or 'severe bleeding', transfusion reactions or adverse events between pathogen-reduced and standard platelets. For a range of laboratory outcomes the results indicated evidence of some benefits for standard platelets over pathogen-reduced platelets. These conclusions are based on data from 1422 patients included in 10 trials. Results from ongoing or new trials are required to determine if there are clinically important differences in bleeding risk between pathogen-reduced platelet transfusions and standard platelet transfusions. Given the variability in trial design, bleeding assessment and quality of outcome reporting, it is recommended that future trials apply standardised approaches to outcome assessment and follow-up, including safety reporting.

Photochemical inactivation of chikungunya virus in human apheresis platelet components by amotosalen and UVA light

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that recently re-emerged in Africa and rapidly spread into countries of the Indian Ocean basin and South-East Asia. The mean viremic blood donation risk for CHIKV on La Réunion reached 1.5% at the height of the 2005-2006 outbreaks, highlighting the need for development of safety measures to prevent transfusion-transmitted infections. We describe successful inactivation of CHIKV in human platelets and plasma using photochemical treatment with amotosalen and long wavelength UVA illumination. Platelet components in additive solution and plasma units were inoculated with two different strains of high titer CHIKV stock (6.0-8.0 logs/mL), and then treated with amotosalen and exposure to 1.0-3.0 J/cm² UVA. Based on in vitro assays of infectious virus pre- and post-treatment to identify endpoint dilutions where virus was not detectable, mean viral titers could effectively be reduced by > 6.4 ± 0.6 log₁₀ TCID₅₀/mL in platelets and ≥ 7.6 ± 1.4 logs in plasma, indicating this treatment has the capacity to prevent CHIKV transmission in human blood components collected from infected donors in or traveling from areas of CHIKV transmission.

Proteomic analysis of Intercept-treated platelets

In the past decades, transfusion medicine has been driven by the quest for increased safety against transfusion-transmitted infections, mainly by better donor selection and by the development of improved serological and nucleic-acid-based screening assays. Recently, pathogen reduction technologies became available and started to be implemented in several countries, with the primary goal to fight against bacterial contamination of blood products, a rare but dramatic event against which there was no definitive measure. Though pathogen reduction technologies represent a quantum leap in transfusion safety, the biomedical efficacy of platelet concentrates (PCs) treated with various pathogen reduction techniques has been recently questioned by clinical studies. Here, a gel-based proteomic analysis of PCs (n=5), Intercept-treated or untreated, from pooled buffy-coat (10 donors per PC) at Days 1, 2 and 8, shows that the Intercept process that is the most widespread pathogen reduction technique to date, has relatively low impact on the proteome of treated platelets: the process induces modifications of DJ-1 protein, glutaredoxin 5, and G(i)alpha 2 protein. As for the impact of storage, chloride intracellular channel protein 4 (CLIC4) and actin increased independently of Intercept treatment during storage. Whereas alteration of the DJ-1 protein and glutaredoxin 5 points out an oxidative stress-associated lesion, modification of G(i)alpha2 directly connects a possible Intercept-associated lesion to haemostatic properties of Intercept-treated platelets. This article is part of a Special Issue entitled: Integrated omics.

Oxygen measurements in platelet fluids - a new non-invasive method to detect bacterial contaminations in platelets

BACKGROUND

The residual risk for bacterial contamination in blood components especially in platelets is one to two orders of magnitude higher than for transfusion relevant viral infections. The majority of all bacterial transmitted fatalities occurred at the end of platelet shelf life. Therefore, the maximum shelf life of platelet concentrates (PC) was reduced to 4 days after blood donation in Germany in 2008.

METHODS

A new continuous non-invasive bacterial detection method was developed by O(2) measurements in the platelet fluids and tested with 10 transfusion relevant bacteria species.

RESULTS

The bacterial concentration at the time point of a positive signal of PreSense O(2) ranged between 10(2) and 10(5) CFU mL(-1) . Harmful transfusion-transmitted bacterial infection would have probably been prevented by this novel technology. Only strict anaerobic bacteria strains like Clostridium perfringens were not detected within the study period of 72 h.

CONCLUSIONS

The described non-invasive bacterial detection method represents a new approach to prevent transmission of bacterial infection in platelets. The method is characterised by the advantage that all investigations can be performed until right up to the time of transfusion, and therefore, reduce the risk for sample errors to a minimum.