Flow path system of ultraviolet C irradiation from xenon flash to reduce bacteria survival in platelet products containing a platelet additive solution.

BACKGROUND: Our previous study showed that ultraviolet C (UVC) from xenon (Xe) flash without any photoreactive compounds inactivated bacteria in platelet concentrates (PCs) with less damage to platelets (PLTs) as compared with Xe flash containing ultraviolet A, ultraviolet B, and visible light. Here, we report a UVC irradiation system for PCs under flow conditions consisting of a flow path-irradiation sheet, a peristaltic pump, and a collection bag. STUDY DESIGN AND METHODS: Platelet concentrates containing Ringer's solution (R-PCs) inoculated with bacteria were injected into a flow path sheet using a peristaltic pump, being irradiated with UVC from Xe flash. The quality of the irradiated PCs containing platelet additive solution (PAS-PCs) was assessed based on PC variables, PLT surface markers, and aggregation ability. RESULTS: Streptococcus dysgalactiae (12 tests) and Escherichia coli (11) were all negative on bacterial culture, while Staphylococcus aureus (12) and Klebsiella pneumoniae (14) grew in one and two R-PCs, respectively. Bacillus cereus spores were inactivated in 7 of 12 R-PCs. PC variables became significantly different between irradiated and nonirradiated PAS-PCs. P-selectin, first procaspase-activating compound (PAC-1) binding, and phosphatidylserine increased by irradiation. Aggregability stimulated by adenosine diphosphate, collagen, or thromboxane A2 increased in the irradiated PAS-PCs, while that by thrombin became smaller compared with nonirradiated controls. CONCLUSION: This newly developed system inactivated bacteria including spores in R-PCs. PAS-PCs irradiated by this system retained acceptable in vitro quality and aggregability. Usage of a peristaltic pump instead of agitator during irradiation may enable this system to be directly combined with an apheresis blood cell separator.

The Brazilian experience of nucleic acid testing to detect human immunodeficiency virus, hepatitis C virus, and hepatitis B virus infections in blood donors.

BACKGROUND: The history of the development and implementation of the Brazilian nucleic acid testing (NAT) platform to detect and discriminate among human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) infections in blood donors is described here. The results for the sensitivity, reproducibility, and NAT yield of the platform since program implementation are provided. STUDY DESIGN AND METHODS: The Brazilian NAT HIV, HCV, and HBV kit was developed and evaluated with regard to analytical sensitivity, specificity, intralot and interlot reproducibility, interfering substances, and genotype and diagnostic sensitivity. Additionally, a sample of identified NAT-yield cases was characterized with regard to viral load. RESULTS: The 95% limits of detection for HIV, HCV, and HBV were 68.02, 102.35, and 9.08 IU/mL, respectively. All replicates were detected with reproducibility assays between the acceptable values. A total of 13,610,536 blood donors was screened from 2010 to 2016, and 63 HIV-yield cases and 28 HCV-yield cases were detected. Among 5,795,424 blood donors screened for HBV from 2014 to 2016, 42 yield cases were found. CONCLUSION: The Brazilian NAT HIV, HCV, and HBV kit is an automated NAT system suitable for routine blood donor screening in a completely traceable process. The analytical sensitivity as well as the diagnostic sensitivity fulfilled all requirements set by the health ministry for blood donor screening. A significant number of transmission cases were prevented by the implementation of this important program.

Towards bedside washing of stored red blood cells: a prototype of a simple apparatus based on microscale sedimentation in normal gravity.

BACKGROUND AND OBJECTIVES: Infusion of by-products of red blood cell (RBC) storage-induced degradation as well as of the residual plasma proteins and the anticoagulant-preservative solution contained in units of stored blood serve no therapeutic purpose and may be harmful to some patients. Here, we describe a prototype of a gravity-driven system for bedside washing of stored RBCs. MATERIALS AND METHODS: Stored RBCs were diluted to 10% haematocrit (Hct) with normal saline, matching the conventional washing procedure. The dilute RBC suspensions were passed through a column of coiled tubing to allow RBC sedimentation in normal gravity, thus separating them from the washing solution. Washed RBCs were collected using bifurcations located along the tubing. Washing efficiency was quantified by measuring Hct, morphology, deformability, free haemoglobin and total-free protein. RESULTS: The gravity-driven washing system operating at 0·5 ml/min produced washed RBCs with final Hct of 36·7 ± 3·4% (32·3-41·2%, n = 10) and waste Hct of 3·4 ± 0·7% (2·4-4·3%, n = 10), while removing 80% of free haemoglobin and 90% of total-free protein. Washing improved the ability of stored RBCs to perfuse an artificial microvascular network by 20%. The efficiency of washing performed using the gravity-driven system was not significantly different than that of conventional centrifugation. CONCLUSIONS: This proof-of-concept study demonstrates the feasibility of washing stored RBCs using a simple, disposable system with efficiency comparable to that of conventional centrifugation, and thus represents a significant first step towards enabling low-cost washing of stored blood at bedside.

UK approach to assessing assays and filters designed to reduce the risk of transfusion-transmitted vCJD.

Three cases of vCJD transmission by blood transfusion have been reported in the UK, and a fourth case discovered at post-mortem. Modelling has been conducted to predict the number of cases that may occur in the future through transfusion, based on estimates of prevalence, infectivity and susceptibility, and a number of steps have been taken to reduce the risk of transmission. These include deferral of previously transfused donors, leucocyte depletion of all components, importation of plasma for certain patient groups and for fractionation, and the collection of the majority of platelets from single donors (by apheresis). However, even with these interventions, some future cases are still predicted. The UK-wide Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO) considers the evidence for clinical and cost-effectiveness of any proposed intervention, such as prion assays and filters, and makes recommendations to the governments of the UK. The development of prion assays is challenging as prions do not generate an immune response, do not have nucleic acid and are present in blood in very low concentrations against a high background of normal prion protein. It is critically important that prion assays show high levels of sensitivity and - especially -specificity for a healthy blood donor population. Assessment is impacted by the very short supply of positive human samples, necessitating the use of animal models. Filters that are capable of removing prions from blood components have been developed and CE marked, but it is again necessary to use animal models to study their efficacy. Guidelines have been produced for the assessment of the quality of red cells filtered through these devices, and a clinical safety study has recently been completed. In conclusion, the evaluation of screening assays and prion filters is challenging, time-consuming and costly, but these evaluations are critical to policy making.

Development of a riboflavin and ultraviolet light-based device to treat whole blood.

BACKGROUND: In the United States, blood components are commonly used for patients in need of massive transfusion after blood loss. In combat situations, when severe traumatic injuries occur far from a hospital, fresh whole blood is a valuable transfusion therapy because components may not be available. The risk of infectious or immunological complications from fresh whole blood transfusions could be mitigated by a system that reduces pathogen loads and inactivates white blood cells (WBCs). Such a system is in development and utilizes riboflavin and ultraviolet light to provide pathogen reduction and WBC inactivation. STUDY DESIGN AND METHODS: The system has been tested with in vitro and in vivo animal studies to evaluate WBC inactivation and pathogen reduction, and with in vitro studies to assess the function of the treated blood products. RESULTS: Elimination of viable WBCs with the system is equivalent to gamma-irradiation. Results have been reported for reduction of Babesia microti, Trypanosoma cruzi, HIV, and bacteria, and preliminary results for Babesia divergens are available. Treated whole blood, platelets, and plasma maintain coagulation function. Treated red blood cell components exhibit low hemolysis and high adenosine triphosphate levels at the end of storage. CONCLUSIONS: Treatment with riboflavin and ultraviolet light is a promising alternative to gamma-irradiation. Effectiveness of the system against a variety of pathogens has been established, and further studies are planned. The in vitro studies of function indicate that treated whole blood, as well as components from treated whole blood, will provide acceptable hemostasis and perform well in the next phase of in vivo studies.