Risks associated with red blood cell transfusions: potential benefits from application of pathogen inactivation

Pathogen reduced red blood cells as an alternative to irradiated and washed components with potential for up to 42 days storage

BACKGROUND

The urgency of maintaining a safe and adequate blood supply is increasing. One approach to ensure a sufficient supply is to limit the outdating frequency of blood components. Pathogen inactivation technology was developed primarily to increase safety by preventing transmission of infectious diseases. The Intercept Blood System for pathogen reduction of red blood cells (RBC) has additional benefits such as inactivation of leucocytes and removal of plasma and storage debris through centrifugation. Irradiation and automated washing are detrimental to the RBC membrane and often implicate shortened shelf-life. We aimed to assess whether pathogen inactivation can replace RBC irradiation and washing to avoid shelf-life reduction.

MATERIALS AND METHODS

RBC concentrates (No.=48) were pooled-and-split into four study arms, which underwent pathogen inactivation treatment, irradiation, automated washing or no treatment (reference). RBC quality was evaluated during 42 days by assessment of storage lesion. Washing efficacy was defined by IgA and albumin reduction.

RESULTS

Pathogen reduced RBCs had similar membrane preservation to reference RBCs (hemolysis, microvesicles and extracellular potassium ions), whereas the RBCs were negatively impacted by irradiation or automated washing. ATP increased substantially post-pathogen inactivation, while 2,3-DPG decreased. Pathogen inactivation considerably reduced albumin and IgA, though slightly less efficiently than automated washing.

DISCUSSION

RBCs exhibit superior membrane preservation after pathogen inactivation treatment, compared to both irradiation and automated washing. This suggests that replacement is possible, even though the plasma reduction protocol could be further optimised.Replacement of irradiated and washed RBC concentrates with pathogen reduced RBC concentrates storable up to 42 days would be advantageous for both the blood supply and patient safety.

New ultraviolet C light-based method for pathogen inactivation of red blood cell units

BACKGROUND

Pathogen inactivation (PI) technologies for platelet concentrates and plasma are steadily becoming more established, but new PI treatment options for red blood cells (RBCs), the most commonly used blood component, still need to be developed. We present a novel approach to inactivating pathogens in RBC units employing ultraviolet C (UVC) light.

METHODS

Whole blood-derived leukoreduced RBCs suspended in PAGGS-C, a third generation additive solution, served as test samples, and RBCs in PAGGS-C or SAG-M as controls. Vigorous agitation and hematocrit reduction by diluting the RBCs with additional additive solution during illumination ensured that UVC light penetrated and inactivated the nine bacteria and eight virus species tested. Bacterial and viral infectivity assays and in vitro analyses were performed to evaluate the system's PI capacity and to measure the RBC quality, metabolic, functional, and blood group serological parameters of UVC-treated versus untreated RBCs during 36-day storage.

RESULTS

UVC treatment of RBCs in the PAGGS-C additive solution did not alter RBC antigen expression, but significantly influenced some in vitro parameters. Compared to controls, hemolysis was higher in UVC-treated RBC units, but was still below 0.8% at 36 days of storage. Extracellular potassium increased early after PI treatment and reached ≤70 mmol/L by the end of storage. UVC-treated RBC units had higher glucose and 2,3-diphosphoglycerate levels than controls.

CONCLUSION

As UVC irradiation efficiently reduces the infectivity of relevant bacteria and viruses while maintaining the quality of RBCs, the proposed method offers a new approach for PI of RBC concentrates.

Mitigating the risk of transfusion-transmitted infections with vector-borne agents solely by means of pathogen reduction

Background

This study evaluated whether pathogen reduction technology (PRT) in plasma and platelets using amotosalen/ultraviolet A light (A/UVA) or in red blood cells using amustaline/glutathione (S‐303/GSH) may be used as the sole mitigation strategy preventing transfusion‐transmitted West Nile (WNV), dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viral, and Babesia microti, Trypanosoma cruzi, and Plasmodium parasitic infections.

Methods

Antibody (Ab) status and pathogen loads (copies/mL) were obtained for donations from US blood donors testing nucleic acid (NAT)‐positive for WNV, DENV, ZIKV, CHIKV, and B. microti. Infectivity titers derived from pathogen loads were compared to published PRT log₁₀ reduction factors (LRF); LRFs were also reviewed for Plasmodium and T. cruzi. The potential positive impact on donor retention following removal of deferrals from required questioning and testing for WNV, Babesia, Plasmodium, and T. cruzi was estimated for American Red Cross (ARC) donors.

Results

A/UVA and S‐303/GSH reduced infectivity to levels in accordance with those recognized by FDA as suitable to replace testing for all agents evaluated. If PRT replaced deferrals resulting from health history questions and/or NAT for WNV, Babesia, Plasmodium, and T. cruzi, 27,758 ARC donors could be retained allowing approximately 50,000 additional donations/year based on 1.79 donations/donor for calendar year 2019 (extrapolated to an estimated 125,000 additional donations nationally).

Conclusion

Pathogen loads in donations from US blood donors demonstrated that robust PRT may provide an opportunity to replace deferrals associated with donor questioning and NAT for vector‐borne agents allowing for significant donor retention and likely increased blood availability.

Thalassaemia

Thalassaemia is a diverse group of genetic disorders with a worldwide distribution affecting globin chain synthesis. The pathogenesis of thalassaemia lies in the unbalanced globin chain production, leading to ineffective erythropoiesis, increased haemolysis, and deranged iron homoeostasis. The clinical phenotype shows heterogeneity, ranging from close to normal without complications to severe requiring lifelong transfusion support. Conservative treatment with transfusion and iron chelation has transformed the natural history of thalassaemia major into a chronic disease with a prolonged life expectancy, albeit with co-morbidities and substantial disease burden. Curative therapy with allogeneic haematopoietic stem cell transplantation is advocated for suitable patients. The understanding of the pathogenesis of the disease is guiding therapeutic advances. Novel agents have shown efficacy in improving anaemia and transfusion burden, and initial results from gene therapy approaches are promising. Despite scientific developments, worldwide inequality in the access of health resources is a major concern, because most patients live in underserved areas.

Time from apheresis platelet donation to cold storage: Evaluation of platelet quality and bacterial growth

BACKGROUND

Cold storage reduces posttransfusion survival of platelets; however, it can improve platelet activation, lower risk of bacterial contamination, and extend shelf-life compared to room temperature (RT) storage. To facilitate large-scale availability, manufacturing process optimization is needed, including understanding the impact of variables on platelet potency and safety. Short time requirements from collection to storage is challenging for large blood centers to complete resuspension and qualify platelets for production. This study evaluated the impact of time from platelet component collection to cold storage on in vitro properties and bacterial growth.

STUDY DESIGN AND METHODS

Double-apheresis platelet components were collected from healthy donors, suspended in 65% PAS-III/35% plasma, and split into 2 equal units. One unit was placed into cold storage within 2 h and the other unit after 8 h. Eight matched pairs were evaluated for 12 in vitro parameters. Twenty-four matched pairs were evaluated with 8 bacterial strains tested in triplicate. Samples were tested throughout 21 days of storage.

RESULTS

In vitro properties were not different between 2 and 8 h units, and trends throughout storage were similar between arms. Time to cold storage did not significantly impact bacterial growth, with <1 log₁₀ difference at all timepoints between units.

DISCUSSION

Our studies showed that extending time to cold storage from 2 to 8 h from collection did not significantly increase the bacterial growth, and the platelet component quality and function is maintained. The ability to extend the time required from collection to storage will improve blood center logistics to feasibly produce CSPs.

Blood Product (Donor) Noninfectious and Infectious Testing and Modification

Blood transfusion begins with safe donor selection and testing. In the United States, the blood supply and transfusion are highly regulated. Blood transfusion safety is multifaceted, whereby each of the elements of the blood safety value chain, spanning donor recruitment and qualification, to collection, blood processing, testing, transfusion practice, and posttransfusion surveillance, must be optimized to minimize risk. Pathogen inactivation is a promising approach to decrease bacterial contamination of platelets, inactivate parasites and viruses, and decrease risks associated with emerging and unidentified pathogens. This article offers an overview of blood donor infectious and noninfectious testing in the United States.

Low rates of transfusion-transmitted infection screening in chronically transfused adults with sickle cell disease

BACKGROUND

Adults with sickle cell disease (SCD) on chronic transfusion therapy are exposed to a large volume of blood products, thus increasing their risk of transfusion-associated human immunodeficiency virus (HIV), hepatitis C (HCV), and hepatitis B (HBV).

METHODS

We performed a systematic chart review of chronically transfused SCD subjects at the Johns Hopkins Sickle Cell Center for Adults between October 2014 and September 2019 to determine our Center's adherence to the 2014 National Heart, Lung and Blood Institute (NHLBI) SCD guidelines for annual screening for Transfusion Transmitted infections (TTI) and assessed HBV immunity and HBV vaccination rates.

RESULTS

The study included 85 subjects with a median age of 34 years (23-63); 52% were female. No subject received annual screening; 68 subjects (80%) were screened for HIV, 60 subjects (71%) for HCV and 53 subjects (62%) for HBV infections at least once in the study period. Of those screened, one patient was newly diagnosed with HCV infection, and none with HIV or HBV infection. Among 31 subjects tested for anti-Hepatitis B surface antibody, 16 subjects (52%) tested negative. Nineteen (20%) subjects had HBV vaccination documented.

CONCLUSIONS

Low adherence to the NHLBI TTI screening guidelines, especially for HBV, highlights the resource intensiveness of this patient population. The low rates of anti-Hepatitis B surface antibody positivity highlight the need to confirm vaccination, provide boosters as indicated, and investigate the adults with SCD's immune response to HBV vaccination.

Establishment of transfusion-relevant bacteria reference strains for red blood cells

BACKGROUND AND OBJECTIVES

Red blood cell concentrates (RBCC) are susceptible to bacterial contamination despite cold storage. A reliable evaluation of strategies to minimize the risk of RBCC-associated bacterial transmission requires the use of suitable reference bacteria. Already existing Transfusion-Relevant Bacteria Reference Strains (TRBRS) for platelet concentrates fail to grow in RBCC. Consequently, the ISBT TTID, Working Party, Bacterial Subgroup, conducted an international study on TRBRS for RBCC.

MATERIALS AND METHODS

Six bacterial strains (Listeria monocytogenes PEI-A-199, Serratia liquefaciens PEI-A-184, Serratia marcescens PEI-B-P-56, Pseudomonas fluorescens PEI-B-P-77, Yersinia enterocolitica PEI-A-105, Yersinia enterocolitica PEI-A-176) were distributed to 15 laboratories worldwide for enumeration, identification, and determination of growth kinetics in RBCC at days 7, 14, 21, 28, 35 and 42 of storage after low-count spiking (10-25 CFU/RBCC).

RESULTS

Bacterial proliferation in RBCC was obtained for most strains, except for S. marcescens, which grew only at 4 of 15 laboratories. S. liquefaciens, S. marcescens, P. fluorescens and the two Y. enterocolitica strains reached the stationary phase between days 14 and 21 of RBCC storage with a bacterial concentration of approximately 10⁹  CFU/ml. L. monocytogenes displayed slower growth kinetics reaching 10⁶ -10⁷  CFU/ml after 42 days.

CONCLUSION

The results illustrate the importance of conducting comprehensive studies to establish well-characterized reference strains, which can be a tool to assess strategies and methods used to ameliorate blood safety. The WHO Expert Committee on Biological Standardization adopted the five successful strains as official RBCC reference strains. Our study also highlights the relevance of visual inspection to interdict contaminated RBC units.

New strategies for the control of infectious and parasitic diseases in blood donors: the impact of pathogen inactivation methods

Around 70 infectious agents are possible threats for blood safety.

The risk for blood recipients is increasing because of new emergent agents like West Nile, Zika and Chikungunya viruses, or parasites such as Plasmodium and Trypanosoma cruzi in non-endemic regions, for instance.

Screening programmes of the donors are more and more implemented in several Countries, but these cannot prevent completely infections, especially when they are caused by new agents.

Pathogen inactivation (PI) methods might overcome the limits of the screening and different technologies have been set up in the last years.

This review aims to describe the most widely used methods focusing on their efficacy as well as on the preservation integrity of blood components.

Preclinical safety assessment of pathogen reduced red blood cells treated with amustaline and glutathione

BACKGROUND

The nucleic acid targeted pathogen reduction (PR) system utilizing amustaline (S-303) and glutathione (GSH) is designed to inactivate blood-borne pathogens and leukocytes in red blood cell concentrates (PR-RBCC). Inactivation is attained after amustaline intercalates and forms covalent nucleic acid adducts preventing replication, transcription, and translation. After pathogen inactivation, amustaline spontaneously hydrolyzes to S-300, the primary negatively charged reaction product; amustaline is below quantifiable levels in PR-RBCC. GSH quenches free unreacted amustaline.

STUDY DESIGN AND METHODS

The genotoxic and carcinogenic potential of PR-RBCC, the reaction by-products, and S-300 were assessed in accordance with the International Conference on Harmonization (ICH) guidelines and performed in compliance with the Food and Drug Administration (FDA) good laboratory practice standards, 21 CFR Part 58. in vitro bacterial reverse mutagenicity and chromosomal aberration assays were performed with and without exogenous S9 metabolic activation, and in in vivo clastogenicity and carcinogenic assays using validated murine models.

RESULTS

PR-RBCCs were not genotoxic in vitro and in vivo and were non-carcinogenic in p53^+/- transgenic mice transfused over 26 weeks. Estimated safety margins for human exposure ranged from >90 to >36 fold for 2 to 5 PR-RBCCs per day, respectively. PR-RBCCs and S-300 did not induce chromosome aberration in the in vivo murine bone marrow micronucleus assay at systemically toxic doses.

CONCLUSIONS

PR-RBCCs did not demonstrate genotoxicity in vitro or in vivo and were not carcinogenic in vivo. These studies support the safety of PR-RBCCs and suggest that there is no measurable genotoxic hazard associated with transfusion of PR-RBCCs.

Nucleic acid-targeted pathogen reduction technique in red blood cells by UV-generated oxygen radicals for optimising recipient safety

OBJECTIVES

A novel pathogen reduction technique based on vacuum ultraviolet (VUV) irradiation was developed to reduce pathogen numbers in red blood cell (RBC) components.

BACKGROUND

Contaminated blood components pose a great risk of infection in blood recipients. The continuous development of blood screening techniques and pathogen inactivating systems has significantly reduced this risk, but many limitations remain.

METHODS

Escherichia coli and Bacillus cereus, and bacteriophage (BP) and Lentivirus (LV) were spiked into suspended red blood cells (sRBCs) or plasma. VUV light with maximum emission at 185 nm and an average dosage of 164 μW/cm² was placed 5 cm above the targeted products to reduce the pathogen numbers.

RESULTS

Treatment for 5 minutes was effective; 3 and 10 log reductions of E coli counts were observed in sRBCs and plasma, and 2 and 3 log reductions of B cereus counts were observed in sRBCs and plasma, respectively. The BP titre was reduced by two and five log points in sRBCs and plasma, respectively; the LV titre was reduced by at least three log points in both sRBCs and plasma. VUV-based irradiation of RBCs does not cause significant structural and functional harmful effects. This novel strategy provides moderate photonic energy to generate oxygen radicals from H₂ O and O₂ and to selectively decrease DNA integrity of the potential pathogens.

CONCLUSION

The VUV-based pathogen reduction technique is a simple and fast procedure with high pathogen reduction efficacy, low toxicity and limited adverse effects on cellular blood products.

An evidence-based review of enhanced recovery after surgery in total knee replacement surgery

Rationale: Enhanced recovery after surgery is gaining popularity among orthopaedic surgeons across the globe and hence a strong evidence base had to be reviewed to make an evidence-based sustainable protocol.

Methods

The following databases, PubMed, OVID, Cochrane database and EMBASE were searched. The search was limited to 15 components of enhanced recovery after surgery programme which is divided into preoperative, intraoperative and postoperative phases. Inclusion criteria were restricted to articles published in English within the last 15 years and articles comprising of unicompartmental arthroplasty, revision knee arthroplasty, bilateral simultaneous knee arthroplasty and only hip arthroplasty excluded. The full texts were analysed and controversies and limitations of various studies were summarised.

Discussion

Each component of the programme was thoroughly reviewed and strength and weaknesses of the evidence base summarised. The strength of the evidence was assessed by critically appraising the study methodology and justifying the appropriateness of the inclusion in enhanced recovery after surgery protocol.

Conclusion

Enhanced recovery after surgery has already been used successfully in various surgical specialities. Enhanced recovery after surgery programmes in knee arthroplasty are yet to be established as a universal practice to be adopted globally. This evidence-based review provides an insight into the best evidence linked to each component and their rationale for inclusion in the proposed enhanced recovery after surgery protocol.

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.

Amustaline-glutathione pathogen-reduced red blood cell concentrates for transfusion-dependent thalassaemia

Transfusion‐dependent thalassaemia (TDT) requires red blood cell concentrates (RBCC) to prevent complications of anaemia, but carries risk of infection. Pathogen reduction of RBCC offers potential to reduce infectious risk. We evaluated the efficacy and safety of pathogen‐reduced (PR) Amustaline‐Glutathione (A‐GSH) RBCC for TDT. Patients were randomized to a blinded 2‐period crossover treatment sequence for six transfusions over 8–10 months with Control and A‐GSH‐RBCC. The efficacy outcome utilized non‐inferiority analysis with 90% power to detect a 15% difference in transfused haemoglobin (Hb), and the safety outcome was the incidence of antibodies to A‐GSH‐PR‐RBCC. By intent to treat (80 patients), 12·5 ± 1·9 RBCC were transfused in each period. Storage durations of A‐GSH and C‐RBCC were similar (8·9 days). Mean A‐GSH‐RBCC transfused Hb (g/kg/day) was not inferior to Control (0·113 ± 0·04 vs. 0·111 ± 0·04, P = 0·373, paired t‐test). The upper bound of the one‐sided 95% confidence interval for the treatment difference from the mixed effects model was 0·005 g/kg/day, within a non‐inferiority margin of 0·017 g/kg/day. A‐GSH‐RBCC mean pre‐transfusion Hb levels declined by 6·0 g/l. No antibodies to A‐GSH‐RBCC were detected, and there were no differences in adverse events. A‐GSH‐RBCCs offer potential to reduce infectious risk in TDT with a tolerable safety profile.

Prevention of transfusion-transmitted infections

Since the 1970s, introduction of serological assays targeting virus-specific antibodies and antigens has been effective in identifying blood donations infected with the classic transfusion-transmitted infectious agents (TTIs; hepatitis B virus [HBV], HIV, human T-cell lymphotropic virus types I and II, hepatitis C virus [HCV]). Subsequently, progressive implementation of nucleic acid-amplification technology (NAT) screening for HIV, HCV, and HBV has reduced the residual risk of infectious-window-period donations, such that per unit risks are <1 in 1 000 000 in the United States, other high-income countries, and in high-incidence regions performing NAT. NAT screening has emerged as the preferred option for detection of newer TTIs including West Nile virus, Zika virus (ZIKV), and Babesia microti Although there is continual need to monitor current risks due to established TTI, ongoing challenges in blood safety relate primarily to surveillance for emerging agents coupled with development of rapid response mechanisms when such agents are identified. Recent progress in development and implementation of pathogen-reduction technologies (PRTs) provide the opportunity for proactive rather than reactive response to blood-safety threats. Risk-based decision-making tools and cost-effectiveness models have proved useful to quantify infectious risks and place new interventions in context. However, as evidenced by the 2015 to 2017 ZIKV pandemic, a level of tolerable risk has yet to be defined in such a way that conflicting factors (eg, theoretical recipient risk, blood availability, cost, and commercial interests) can be reconciled. A unified approach to TTIs is needed, whereby novel tests and PRTs replace, rather than add to, existing interventions, thereby ameliorating cost and logistical burden to blood centers and hospitals.

International survey on the impact of parasitic infections: frequency of transmission and current mitigation strategies

BACKGROUND AND OBJECTIVES

Globally, blood safety interventions have been successful in mitigating risk of the major transfusion-transmitted (TT) viruses. However, strategies that address risk from parasites are comparatively limited. TT parasites are often regional in nature, posing unique challenges; we sought to understand their impact on blood safety.

MATERIALS AND METHODS

An electronic questionnaire was distributed to transfusion medicine leaders in 100 countries. The survey focused on specific questions pertaining to four parasitic diseases: babesiosis, Chagas, leishmaniasis and malaria. Respondents provided data on historical TT cases, local epidemiology, policies to mitigate risk and an assessment of public health perceptions for each aetiologic agent.

RESULTS

Twenty-eight (28%) surveys were returned from countries in Europe (n = 13), the Americas (n = 6), Africa (n = 4), Asia (n = 3) and Oceana (n = 2). Historically, no cases of TT leishmaniasis were reported, TT babesiosis was exclusive to Canada and the USA, TT Chagas was limited to the Americas and Spain, while TT malaria was cosmopolitan. Mitigation efforts varied widely; malaria was the most frequently tested parasitic disease. The public's perception of risk for parasitic agents was low, while that of health authorities in endemic countries was higher.

CONCLUSION

The global impact of parasitic infections on blood safety and related mitigation efforts varied widely by parasite epidemiology, test availability, public health priorities and socioeconomic constraints. While parasites continue to pose a risk to blood safety, the successful mitigation of viral risk has elevated the prominence of TT parasites in many locations, thereby requiring consideration of mitigation efforts.

Tranexamic acid use during total hip arthroplasty: A single center retrospective analysis

BACKGROUND

Tranexamic acid (TXA) is an antifibrinolytic agent that has shown promise in reducing blood loss during total hip arthroplasty (THA). Several studies have reported side effects of high-dose TXA administration, including myocardial infarction (MI), thromboembolic events, and seizures. These possible side effects have prevented the widespread adoption of TXA in the surgical community.

METHODS

We conducted a retrospective chart review of 564 primary and revision THAs performed at a single academic center. Surgical patients received either no TXA or 1 g IV TXA at the beginning of surgery followed by a second bolus just before the surgical wound closure, at the surgeon's discretion. We analyzed differences in hemoglobin (Hb), hematocrit (Hct), estimated blood loss (EBL), and adverse events in patients receiving TXA versus patients not receiving TXA up to 2 days following surgery.

RESULTS

Significantly higher Hb and Hct values were found across all time points among patients undergoing primary posterior or revision THA who had received TXA. In addition, transfusion rates were significantly decreased in both primary posterior THAs and revision THAs when TXA was administered. Patients who received TXA experienced significantly fewer adverse events than those who did not for all surgery types.

CONCLUSION

Administration of low-dose intravenous (IV) and intra-articular (IA) TXA does not appear to increase rates of adverse events and may be effective in minimizing blood loss, as reflected by Hb and Hct values following THA.

Red blood cells treated with the amustaline (S-303) pathogen reduction system: a transfusion study in cardiac surgery

BACKGROUND

Nucleic acid-targeted pathogen inactivation technology using amustaline (S-303) and glutathione (GSH) was developed to reduce the risk of transfusion-transmitted infectious disease and transfusion-associated graft-versus-host disease with red blood cell (RBC) transfusion.

STUDY DESIGN AND METHODS

A randomized, double-blind, controlled study was performed to assess the in vitro characteristics of amustaline-treated RBCs (test) compared with conventional (control) RBCs and to evaluate safety and efficacy of transfusion during and after cardiac surgery. The primary device efficacy endpoint was the postproduction hemoglobin (Hb) content of RBCs. Exploratory clinical outcomes included renal and hepatic failure, the 6-minute walk test (a surrogate for cardiopulmonary function), adverse events (AEs), and the immune response to amustaline-treated RBCs.

RESULTS

A total of 774 RBC unis were produced. Mean treatment difference in Hb content was -2.27 g/unit (95% confidence interval, -2.61 to -1.92 g/unit), within the prespecified equivalence margins (±5 g/unit) to declare noninferiority. Amustaline-treated RBCs met European guidelines for Hb content, hematocrit, and hemolysis. Fifty-one (25 test and 26 control) patients received study RBCs. There were no significant differences in RBC usage or other clinical outcomes. Observed AEs were within the spectrum expected for patients of similar age undergoing cardiovascular surgery requiring RBCs transfusion. No patients exhibited an immune response specific to amustaline-treated RBCs.

CONCLUSION

Amustaline-treated RBCs demonstrated equivalence to control RBCs for Hb content, have appropriate characteristics for transfusion, and were well tolerated when transfused in support of acute anemia. Renal impairment was characterized as a potential efficacy endpoint for pivotal studies of RBC transfusion in cardiac surgery.

Towards pathogen inactivation of red blood cells and whole blood targeting viral DNA/RNA: design, technologies, and future prospects for developing countries

Over 110 million units of blood are collected yearly. The need for blood products is greater in developing countries, but so is the risk of contracting a transfusion-transmitted infection. Without efficient donor screening/viral testing and validated pathogen inactivation technology, the risk of transfusion-transmitted infections correlates with the infection rate of the donor population. The World Health Organization has published guidelines on good manufacturing practices in an effort to ensure a strong global standard of transfusion and blood product safety. Sub-Saharan Africa is a high-risk region for malaria, human immunodeficiency virus (HIV), hepatitis B virus and syphilis. Southeast Asia experiences high rates of hepatitis C virus. Areas with a tropical climate have an increased risk of Zika virus, Dengue virus, West Nile virus and Chikungunya, and impoverished countries face economical limitations which hinder efforts to acquire the most modern pathogen inactivation technology. These systems include Mirasol® Pathogen Reduction Technology, INTERCEPT®, and THERAFLEX®. Their procedures use a chemical and ultraviolet or visible light for pathogen inactivation and significantly decrease the threat of pathogen transmission in plasma and platelets. They are licensed for use in Europe and are used in several other countries. The current interest in the blood industry is the development of pathogen inactivation technologies that can treat whole blood (WB) and red blood cell (RBC). The Mirasol system has recently undergone phase III clinical trials for treating WB in Ghana and has demonstrated some efficacy toward malaria inactivation and low risk of adverse effects. A 2nd-generation of the INTERCEPT® S-303 system for WB is currently undergoing a phase III clinical trial. Both methodologies are applicable for WB and components derived from virally reduced WB or RBC.

Inactivation of Babesia microti in red blood cells and platelet concentrates

BACKGROUND

With an increasing number of recognized transfusion-transmitted (TT) babesiosis cases, Babesia microti is the most frequently TT parasite in the United States. We evaluated the inactivation of B. microti in red blood cells (RBCs) prepared in Optisol (AS-5) using amustaline and glutathione (GSH) and in platelet components (PCs) in 100% plasma using amotosalen and low-energy ultraviolet A (UVA) light.

STUDY DESIGN AND METHODS

Individual RBCs and apheresis PCs were spiked with B. microti-infected hamster RBCs (iRBCs) to a final concentration of 10⁶ iRBCs/mL and treated with the respective inactivation systems according to the manufacturer's instruction. Samples were collected before (control) and after (test) each treatment. Dilutions of the control samples to 10^-6 were inoculated into hamsters, while the test samples were inoculated neat or at 10^-1 dilution. At 3 and 5 weeks postinoculation, hamsters were evaluated for B. microti infection by microscopic observation of blood smears and 50% infectivity titers (ID₅₀ ) were determined. Log reduction was calculated as control log ID₅₀ minus test log ID₅₀ .

RESULTS

Parasitemia was detected in hamsters injected with as low as 100,000-fold diluted control samples, while no parasites were detectable in the blood smears of any hamsters receiving neat test samples. Mean log reduction was more than 5 log/mL by amustaline/GSH for RBCs and more than 4.5 log/mL by amotosalen/UVA for PCs.

CONCLUSION

B. microti was inactivated to the limit of detection in RBCs and PCs after the respective inactivation treatment. Complete inactivation of B. microti was achieved in this animal infectivity model, and pathogen reduction treatment inhibited transmission of infection.

Indications for and complications of transfusion and the management of gynecologic malignancies

Anemia, which is highly prevalent in oncology patients, is one of the most established negative prognostic factors for several gynecologic malignancies. Multiple factors can cause or contribute to the development of anemia in patients with gynecologic cancers; these factors include blood loss (during surgery or directly from the tumor), renal impairment (caused by platinum-based chemotherapy), and marrow dysfunction (from metastases, chemotherapy, and/or radiation therapy). Several peri- and intra-operative strategies can be used to optimize patient management and minimize blood loss related to surgery. Blood transfusions are routinely employed as corrective measures against anemia; however, blood transfusions are one of the most overused healthcare interventions. There are safe and effective evidence-based blood transfusion strategies used in other patient populations that warrant further investigation in the surgical oncology setting. Blood is a valuable healthcare resource, and clinicians can learn to use it more judiciously through knowledge of the potential risks and complications of blood interventions, as well as the ability to properly identify the patients most likely to benefit from such interventions.

Transfusion practices and infectious risks

Transfusion-transmitted infections remain among the most-feared complications of allogeneic blood transfusion. Thanks to several strategies including donor screening and deferral, blood testing and pathogen inactivation, their risks have reached all-time low levels, particularly in developed nations. Nonetheless, new and emerging infections remain a threat that is likely to exacerbate in the coming years with continued globalization and climate change. More effective strategies of pathogen inactivation and more vigilant horizon screening are hoped to abate the risk. Additionally, allogeneic transfusion has repeatedly been shown to be associated with worsening of outcomes in patients, including the documented increased risk of infections (often nosocomial) in recipients of transfusions. The underlying mechanism is likely to be related to immunosuppressive effects of allogeneic blood, iron content, and bacterial contamination. This issue is best addressed by more judicious and evidence-based use of allogeneic blood components to ensure the potential benefits outweigh the risks.

Recent Advances in Preventing Adverse Reactions to Transfusion

The spectrum of adverse reactions to blood product transfusion ranges from a benign clinical course to serious morbidity and mortality.  There have been many advances in technologies and transfusion strategies to decrease the risk of adverse reactions. Our aim is to address a few of the advancements in increasing the safety of the blood supply, specifically pathogen reduction technologies, bacterial contamination risk reduction, and transfusion associated acute lung injury risk mitigation strategies.