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BACKGROUND: Photochemical pathogen inactivation treatment (PCT) of plasma components with amotosalen and UVA has been implemented in Europe. To establish a postapproval safety database, an active hemovigilance (HV) program utilizing an electronic data capture system (EDCS) was initiated. STUDY DESIGN AND METHODS: The response to transfusion was documented after each PCT-plasma transfusion. The primary outcome was the incidence of acute transfusion reactions (ATRs) within 24 hours of transfusion. An ATR was defined as an adverse event (AE) possibly related, probably related, or related to the PCT-plasma transfusion. For AEs, the following were collected: time of event after transfusion, clinical description, vital signs, clinical and laboratory test results, severity (Grade 0-4), seriousness, and causal relationship to transfusion of PCT-plasma. RESULTS: To date, 3232 patients (59.1% male) with a primary indication for plasma transfusion due to a hematology disorder (23.1%), surgery (32.4%), or a general medical condition (44.4%) received 7483 PCT-plasma transfusions (composed of 19,069 apheresis plasma components). The mean age of the patient population was 57.3 years (2884 adults, 160 children, and 188 infants). ATRs were reported for 8/7483 transfusions (0.11%; 95% confidence interval [CI], 0.03-0.19) and 8/3232 patients (0.25%; 95% CI, 0.08-0.42%). Five ATRs were of Grade 1 severity. The remaining three ATRs were classified as serious. No deaths or episodes of transfusion-related acute lung injury attributed to a PCT-plasma transfusion were reported. CONCLUSION: PCT-plasma transfusions were well tolerated in routine clinical use. The EDCS HV program facilitated collection and reporting of safety information on a real-time basis from multiple sites.

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

BACKGROUND: It is estimated that approximately 300,000 neonates undergo transfusions annually. The neonatal immune system is immature, making such patients more susceptible to the effects associated with transfusion-transmitted bacteria, viruses, protozoa, and white blood cells (WBCs). The INTERCEPT Blood System is a photochemical process (PCT) utilizing amotosalen and long-wavelength ultraviolet to inactivate pathogens and WBCs in both platelet (PLT) and plasma components for transfusion. A series of clinical studies has shown PCT PLTs and PCT plasma to be safe and effective for transfusion in adults and pediatric patients. Because clinical studies in neonates are technically difficult and ethically challenging, preclinical toxicologic studies were conducted in neonatal rats to evaluate the safety of PCT blood components for neonates. STUDY DESIGN AND METHODS: This study examined daily intravenous administration to neonatal rats of amotosalen in 35 percent:65 percent plasma:InterSol from 1 µg per kg per day (representing 1-unit transfusion) to 457 µg per kg per day (representing multiple transfusions) from Postnatal Day 4 (PND4) to PND31. Rats were observed for viability, clinical signs, and body weights until PND31 and then subjected to pathology evaluation. Hematology, clinical chemistry, and urinalysis data were also collected on PND31. Toxicokinetic parameters were evaluated on PND4 and PND31. RESULTS: There were no amotosalen-related effects on clinical signs, body weight, hematology, clinical chemistry, urinalysis, gross pathology, or histopathology, despite the exposure of neonatal rats to amotosalen concentrations as high as approximately 48 times the standard exposure in adult patients. CONCLUSION: This study demonstrates the safety of PCT for transfusion in neonatal rats and augments data from other studies and clinical use supporting the use of PCT in neonatal patients.

We hypothesized that increased Ku70 expression could be involved in recovery following cerebral hypoxia–ischemia. We investigated the progression of cerebral alterations in Ku70 expression at different time points (24 h, 72 h, 1 week, 4 weeks and 8 weeks) after hypoxia–ischemia (right carotid artery occlusion plus 1.5 h of hypoxia) in neonatal rats. To determine whether in addition to its known role of DNA repair, Ku70 was associated with cell death or cell proliferation we performed double staining for Ku70 and DNA fragmentation or bromodeoxyuridine, respectively. The results show that Ku70 expression was increased in the infarct core and peri-infarct regions at 24 h following hypoxia–ischemia. The increased Ku70 expression was transient in the infarct core with a loss of Ku70 positive cells over days. In contrast, in the peri-infarct region the expression of Ku70 remained increased at chronic times 8 weeks following the insult. Cells positive for DNA fragmentation were not co-localized with cells positive for Ku70 after an insult. However, most of the cells positive for bromodeoxyuridine indicative of cell proliferation were positive for Ku70 in the peri-infarct region at 8 weeks after the insult. Considering the roles of Ku70 in DNA repair or inhibiting apoptosis and its co-localization within cells that had undergone proliferation, Ku70 may be considered a potential novel target to enhance recovery following hypoxia–ischemia.

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

BACKGROUND This study evaluated the efficacy of photochemical treatment (PCT) with amotosalen and ultraviolet A (UVA) light to inactivate Trypanosoma cruzi in contaminated platelet (PLT) components. STUDY DESIGN AND METHODS Fifteen pools of buffy-coat PLTs (BC-PLTs) were inoculated with approximately 5 x 10(3) to 5 x 10(5) per mL of viable T. cruzi of the G, Tulahuen (T), or Y strains. Samples from BC-PLTs were assayed for infectivity before and after PCT with 150 micromol per L amotosalen and 3 J per cm(2) UVA light. Infectivity was determined with three different methods: 1) in vitro culture to detect viable epimastigotes, 2) [(3)H]thymidine incorporation in culture, and 3) in vivo inoculation into interferon-gamma receptor (IFN-gammaR)-deficient mice. RESULTS The in vitro assay yielded viable parasite titers of 3.9 x 10(5), 2.8 x 10(4), and 5.6 x 10(3) per mL (corresponding to 5.6, 4.4, and 3.8 logs/mL) for the Y, T, and G strains, respectively. PCT was able to inactivate all three strains of T. cruzi to below the limit of detection (10 parasites/mL) in the sensitive in vivo assay. Because 10-mL samples, each concentrated into a 1-mL sample for inoculation, were tested in the in vivo assay, log reductions achieved were greater than 5.6, greater than 4.4, and greater than 3.8 for the Y, T, and G strains of T. cruzi, respectively. CONCLUSIONS The pathogen reduction system with amotosalen HCl and UVA demonstrated robust efficacy for inactivation of high doses of three different strains of T. cruzi and offers the potential to make the PLT supply safer.

Background. In evaluating a photochemical treatment process for inactivating parvovirus B19, there lacked simple culture methods to measure infectivity. The recently developed enzyme‐linked immunospot (ELISpot) infectivity assay uses late‐stage erythropoietic progenitor cells and is labor intensive and time consuming. We evaluated a novel, efficient polymerase chain reaction (PCR) inhibition assay and examined correlations with reductions in infectivity. Methods. Contaminated plasma was treated with 150 μmol/L amotosalen and 3 J/cm2 ultraviolet A light and then tested for DNA modification using conventional PCR inhibition and a novel preamplification approach. The novel assay subjected the samples to preamplification cycles using long‐template PCR, followed by quantitative PCR (QPCR) inhibition detection. Both approaches were tested for correlations with reductions in viral infectivity by comparing ELISpot assay results of identical samples. Results. The B19 preamplification inhibition assay showed detection ranges of 2–2.5 log and demonstrated quantitative correlation with up to a 5.8‐log reduction in viral infectivity in ELISpot results. Conventional PCR detected a >5 log reduction in amplification, correlated with a 4.4‐log reduction in viral infectivity. A range of 4‐log inhibition of hepatitis B virus DNA amplification was also achieved. Conclusions. The results demonstrated that a novel preamplification QPCR assay is a useful tool for predicting reductions in infectivity after photochemical treatment. This assay was extended to show utility in circumstances where practical in vitro assays are unavailable for the determination of the efficacy of pathogen inactivation.

BACKGROUND: The INTERCEPT Blood System, a photochemical treatment (PCT) process, has been developed to inactivate pathogens in platelet concen-trates. These studies evaluated the efficacy of PCT to inactivate pathogens in plasma and the effect of PCT on plasma function. STUDY DESIGN AND METHODS: Jumbo (600 mL) plasma units were inoculated with high titers of test pathogens and treated with 150 µmol per L amotosalen and 3 J per cm2 long-wavelength ultraviolet light. The viability of each pathogen before and after treatment was measured with biological assays. Plasma function was evaluated through measurement of coagulation factors and antithrombotic protein activities. RESULTS: The levels of inactivation expressed as log-reduction were as follows: cell-free human immunodeficiency virus-1 (HIV-1), greater than 6.8; cell-associated HIV-1, greater than 6.4; human T-lymphotropic virus-I (HTLV-I), 4.5; HTLV-II, greater than 5.7; hepatitis B virus (HBV) and hepatitis C virus, greater than 4.5; duck HBV, 4.4 to 4.5; bovine viral diarrhea virus, 6.0; severe acute respiratory syndrome coronavirus, 5.5; West Nile virus, 6.8; bluetongue virus, 5.1; human adenovirus 5, 6.8; Klebsiella pneumoniae, greater than 7.4; Staphylococcus epidermidis and Yersinia enterocolitica, greater than 7.3; Treponema pallidum, greater than 5.9; Borrelia burgdorferi, greater than 10.6; Plasmodium falciparum, 6.9; Trypanosoma cruzi, greater than 5.0; and Babesia microti, greater than 5.3. Retention of coagulation factor activity after PCT was expressed as the proportion of pretreatment (baseline) activity. Retention was 72 to 73 percent of baseline fibrinogen and Factor (F)VIII activity and 78 to 98 percent for FII, FV, FVII, F IX, FX, FXI, FXIII, protein C, protein S, antithrombin, and α2-antiplasmin. CONCLUSION: PCT of plasma inactivated high levels of a wide range of pathogens while maintaining adequate coagulation function. PCT has the potential to reduce the risk of transfusion-transmitted diseases in patients requiring plasma transfusion support.

Background A photochemical treatment (PCT) system has been developed to inactivate a broad spectrum of pathogens and white blood cells in platelet (PLT) products. The system comprises PLT additive solution (PAS III), amotosalen HCl, a compound adsorption device (CAD), a microprocessor-controlled ultraviolet A light source, and a commercially assembled system of interconnected plastic containers. Study design and methods A clinical prototype of the PCT system was used in a large, randomized, controlled, double-blind, Phase III clinical trial (SPRINT) that compared the efficacy and safety of PCT apheresis PLTs to untreated apheresis PLTs. The ability of multiple users was assessed in a blood center setting to perform the PCT and meet target process specifications. Results Each parameter was evaluated for 2237 to 2855 PCT PLT products. PCT requirements with respect to mean PLT dose, volume, and plasma content were met. Transfused PCT PLT products contained a mean of 3.6 x 10(11) +/- 0.7 x 10(11) PLTs. The clinical process, which included trial-specific samples, resulted in a mean PLT loss of 0.8 x 10(11) +/- 0.6 x 10(11) PLTs per product. CAD treatment effectively reduced the amotosalen concentration from a mean of 31.9 +/- 5.3 micromol per L after illumination to a mean of 0.41 +/- 0.56 micromol per L after CAD. In general, there was little variation between sites for any parameter. Conclusions The PCT process was successfully implemented by 12 blood centers in the United States to produce PCT PLTs used in a prospective, randomized trial where therapeutic efficacy of PCT PLTs was demonstrated. Process control was achieved under blood bank operating conditions.

Although the risk of infection by blood transfusion is relatively low, breakthrough infections still occur, Transfusion-related fatalities caused by infections continue to be reported, and blood is not tested for many potentially dangerous pathogens. The current paradigm for increasing the safety of the blood supply is the development and implementation of laboratory screening methods and restrictive donor criteria. When considering the large number of known pathogens and the fact that pathogens continue to emerge, it is clear that the utility of new tests and donor restrictions will continue to be a challenge when considering the cost of developing and implementing new screening assays, the loss of potential donors, and the risk of testing errors. Despite improving the safety of blood components, testing remains a reactive approach to blood safety. The contaminating organisms must be identified before sensitive tests can be developed. In contrast, pathogen inactivation is a proactive strategy designed to inactivate a pathogen before it enters the blood supply. Almost all pathogen inactivation technologies target nucleic acids, allowing for the inactivation of a variety of nucleic acid-containing pathogens within plasma, platelets, or red blood cells thus providing the potential to reduce transfusion-transmitted diseases. However, widespread use of a pathogen inactivation technology can only be realized when proven safe and efficacious and not cost-prohibitive.

BACKGROUND: A photochemical treatment (PCT) method to inactivate pathogens in platelet concentrates has been developed. The system uses a psoralen, amotosalen HCl, coupled with ultraviolet A (UVA) illumination. STUDY DESIGN AND METHODS: Three sequential clinical trials evaluated viability of PCT platelets prepared with a prototype device. Posttransfusion recovery and lifespan of 111Indium-labeled autologous 5 day-old platelets in healthy subjects was assessed. In the first study, 23 subjects received transfusions of autologous PCT and/or control platelets. In a second study, 16 of these subjects received PCT platelets processed with a Compound Adsorption Device (CAD) (PCT-CAD) to reduce patient exposure to residual amotosalen. In the third study, the effect of gamma-irradiation on PCT platelets was studied. Data from control transfusions from Study A were used for paired comparisons in the latter 2 studies. RESULTS: Mean PCT-CAD platelet recovery for the 16 subjects with paired data was 42.5 ± 8.7% versus 50.3 ± 7.7% for control platelets, mean difference of 7.8% (p

BACKGROUND: Bacterial contamination of platelet (PLT) concentrates can result in transfusion-transmitted sepsis. A photochemical treatment (PCT) process with amotosalen HCl and long-wavelength ultraviolet light (UVA), which cross-links nucleic acids, was developed to inactivate bacteria and other pathogens in PLT concentrates. STUDY DESIGN AND METHODS: High titers of pathogenic aerobic and anaerobic Gram-positive bacteria (10 species), aerobic Gram-negative bacteria (7 species), and spirochetes (2 species) were added to single-donor PLT concentrates containing 3.0 × 1011 to 6.0 × 1011 PLTs in approximately 300 mL of 35 percent plasma and 65 percent PLT additive solution (InterSol, Baxter Healthcare) or saline. After PCT with 150 µmol per L amotosalen and 3 J per cm2 UVA, residual bacterial levels were detected by sensitive microbiologic methods. RESULTS: The level of inactivation of viable bacteria was expressed as log reduction. Log reduction of Gram-positive bacteria for Staphylococcus epidermidis was > 6.6; for Staphylococcus aureus, 6.6; for Streptococcus pyogenes, > 6.8; for Listeria monocytogenes, > 6.3; for Corynebacterium minutissimum, > 6.3; for Bacillus cereus (vegetative), > 5.5; for Lactobacillus sp., > 6.4; for Bifidobacterium adolescentis, > 6.0; for Propionibacterium acnes, > 6.2; and for Clostridium perfringens, > 6.5. Log reduction of Gram-negative bacteria for Escherichia coli was > 6.4; for Serratia marcescens, > 6.7; for Klebsiella pneumoniae, > 5.6; for Pseudomonas aeruginosa, 4.5; for Salmonella choleraesuis, > 6.2; for Yersinia enterocolitica, > 5.9; and for Enterobacter cloacae, 5.9. Log reduction of spirochetes for Treponema pallidum was 6.8 to 7.0, and for Borrelia burgdorferi, > 6.9. CONCLUSION: PCT inactivates high levels of a broad spectrum of pathogenic bacteria. The inactivation of bacteria in PLT concentrates offers the potential to prospectively prevent PLT-transfusion-associated bacteremia.

Background: By inhibiting nucleic acids, photochemical treatment (PCT) using amotosalen hydrochloride (S-59) in combination with UVA light provides a new method for the inactivation of pathogens and leukocytes, potential contaminants of platelet concentrates (PCs). Material and Methods: We evaluated the effect of PCT on function and viability of PCs derived from apheresis over a storage period of 5 days. Double-dose PCs containing 6.5–7.0 × 1011 platelets (n = 8) were collected in 600 ml of approximately 35% autologous plasma and 65% platelet additive solution. Each collection was split into two equal-sized portions for paired analysis. One day after collection, test PCs were mixed with 15 ml of 3 mmol/l S-59 and illuminated with UVA light for 3 min, followed by a 6- to 8-hour incubation in a compound adsorption device (CAD) for the reduction of residual S-59 and unbound photoproducts. In vitro platelet function measurements included platelet count, pH, lactate dehydrogenase (LDH), β-thromboglobulin (β-TG), hypotonic shock response (HSR), extent of shape change (ESC) and the expression of p-selectin. Platelet morphology and ultrastructure were analyzed by light and electron microscopy (EM). Results: We found no statistically significant differences on day 5 of the storage between the control and test platelets for pH, platelet count, p-selectin, ESC, HSR, morphology, and the percentage of lysed platelets analyzed by EM. The level of β-TG was reduced in the test units by the CAD step. Significant differences (p Conclusion: These in vitro results indicate that PCT with amotosalen and UVA light is applicable for split double-dose platelets derived from apheresis as it leads only to a transient activation of platelets immediately after the procedure, without affecting the function and structure of PCs over the 5-day storage period.

Photochemical treatment (PCT) with the psoralen S-59 and long wavelength ultraviolet light (UVA) inactivates high titers of contaminating viruses, bacteria, and leukocytes in human platelet concentrates. The present study evaluated the efficacy of PCT to prevent transfusion-associated graft-versus-host disease (TA-GVHD) in vivo using a well-characterized parent to F1 murine transfusion model. Recipient mice in four treatment groups were transfused with 108 splenic leukocytes. (1) Control group mice received syngeneic splenic leukocyte transfusions; (2) GVHD group mice received untreated allogeneic splenic leukocytes; (3) gamma radiation group mice received gamma irradiated (2,500 cGy) allogeneic splenic leukocytes; and (4) PCT group mice received allogeneic splenic leukocytes treated with 150 μmol/L S-59 and 2.1 J/cm2UVA. Multiple biological and clinical parameters were used to monitor the development of TA-GVHD in recipient mice over a 10-week posttransfusion observation period: peripheral blood cell levels, spleen size, engraftment by donor T cells, thymic cellularity, clinical signs of TA-GVHD (weight loss, activity, posture, fur texture, skin integrity), and histologic lesions of liver, spleen, bone marrow, and skin. Mice in the control group remained healthy and free of detectable disease. Mice in the GVHD group developed clinical and histological lesions of TA-GVHD, including pancytopenia, marked splenomegaly, wasting, engraftment with donor derived T cells, and thymic hypoplasia. In contrast, mice transfused with splenic leukocytes treated with (2,500 cGy) gamma radiation or 150 μmol/L S-59 and 2.1 J/cm2 UVA remained healthy and did not develop detectable TA-GVHD. Using an in vitro T-cell proliferation assay, greater than 105.1 murine T cells were inactivated by PCT. Therefore, in addition to inactivating high levels of pathogenic viruses and bacteria in PC, these data indicate that PCT is an effective alternative to gamma irradiation for prevention of TA-GVHD.

Cytokines generated in platelet concentrates (PCs) during storage have been implicated as possible mediators of febrile nonhemolytic transfusion reactions. Two potential methods of white cell inactivation were compared for their ability to reduce cytokine synthesis in pooled random-donor PC aliquots: treatment with gamma-radiation and photochemical treatment (PCT) using psoralens and ultraviolet A light.ABO-matched PC aliquots were pooled and divided into separate aliquots. Aliquots (20 mL) were taken from each pool to serve as an untreated control and to undergo gamma-radiation. Aliquots were treated by using either gamma-radiation (2500 or 5000 cGy) or virucidal PCT. PCT with the psoralens 8-methoxypsoralen (8-MOP), aminomethyltrimethyl psoralen (AMT), and S-59 was investigated. PC aliquots were stored for 7 days and analyzed for levels of interleukin 8 by use of an enzyme-linked immunosorbent assay. Levels of DNA adduct formation were determined by using 3H-labeled psoralens.Levels of interleukin 8 in the untreated random-donor PC aliquots increased with increasing white cell counts, but they were not affected by pooling. The untreated control aliquots and the aliquots treated with gamma-radiation had significant increases in levels of interleukin 8 after 5 to 7 days of storage (p0.05). PCT with S-59 resulted in a significant reduction in cytokine synthesis (p0.05). Day 5 to 7 levels of interleukin 8 did not differ significantly from Day 0 levels. Inhibition of interleukin 8 production by PCT increased with increasing levels of DNA modification (S-59AMT8-MOP).PCT that utilizes S-59 has been developed to inactivate potential viral and bacterial pathogens in PC aliquots while maintaining in vitro platelet function. These data demonstrate that PCT of aliquots of pooled PC aliquots before storage also prevents white cell cytokine synthesis during storage. PCT may therefore offer the potential for reducing cytokine-associated febrile nonhemolytic transfusion reactions.

A photochemical treatment (PCT) process using a novel psoralen and long wavelength ultraviolet light (UVA, 320-400 nm) has been developed to inactivate bacteria and viruses in platelet concentrates. This study evaluated the efficacy of PCT for inactivation of leukocytes that contaminate platelet preparations. Three psoralens, 8-methoxypsoralen (8-MOP), 4′-aminomethyl 4,5′,8-trimethylpsoralen (AMT), and the novel psoralen S-59, were compared using the following four independent but complementary biological and molecular assays. (1) T-cell viability: Treatment with 150 μmol/L S-59 and 1.0 to 3.0 Joules/cm2 UVA inactivated >5.4 ± 0.3 log10 of T cells in full-sized single-donor plateletpheresis units. Using 1.0 Joule/cm2 UVA, the lowest dose of S-59, AMT and 8-MOP required to reduce the number of T cells to the limit of detection was 0.05 μmol/L, 1.0 μmol/L, and 10.0 μmol/L, respectively. (2) Cytokine synthesis: Treatment with 1.9 Joules/cm2 UVA and 150 μmol/L S-59 or AMT completely inhibited synthesis of the cytokine IL-8 by contaminating leukocytes during 5 days of platelet storage. After treatment with 75 μmol/L 8-MOP and 1.9 Joules/cm2 UVA, only low levels of IL-8 were detected. (3) Psoralen-DNA adduct formation: The combination of 1.9 Joules/cm2 UVA and 150 μmol/L S-59, AMT, or 8-MOP induced 12.0 ± 3.0, 6.0 ± 0.9, and 0.7 psoralen adducts per 1,000 bp DNA, respectively. (4) Replication competence: Polymerase chain reaction (PCR) amplification of small genomic DNA sequences (242-439 bp) after PCT was inhibited. The degree of PCR amplification inhibition correlated with the level of adduct formation (S-59 > AMT > 8-MOP). In contrast, 2,500 cGy gamma radiation, a dose that inactivates >5 log10 of T cells in blood products, had minimal effect on cytokine synthesis and did not induce sufficient DNA strand breaks to inhibit PCR amplification of the same small DNA sequences. These results demonstrate that leukocytes are sensitive to PCT with psoralens and among the psoralens tested S-59 is the most effective. Therefore, PCT has the potential to reduce the incidence of leukocyte-mediated adverse immune reactions associated with platelet transfusion.

Pathogen inactivation using the INTERCEPT Blood System requires platelet resuspension in InterSol and reduced plasma. Platelets in plasma collected on the Haemonetics MCS+ were processed on the INTERCEPT Preparation Set for plasma volume reduction and addition of InterSol. The use of the Preparation Set resulted in a mean platelet loss of 5.6 +/- 3.4%. Subsequent photochemical treatment (PCT) with amotosalen and ultraviolet A light, and 7 days of storage, resulted in acceptable changes for platelet swirling, lactate, lactate dehydrogenase (LDH), platelet factor-4 (PF4), p-selectin, glycoprotein V (GpV), pO2, pCO2, tumour necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8). All platelet units processed with the Preparation Set and PCT met European requirements for leucoreduction and pH values.

The purpose of this study is to present a fuzzy diagnosing machine fault to support the developing machine diagnosis system. The fuzzy evaluation is used to process the problems of which the fault causes and the symptoms are dealing with the uncertainty environment. In this study, we propose two propositions to treat the machine diagnosis fault.

Platelet concentrates (PC) may be infrequently contaminated with low levels of bacteria that can cause septicemia and death in patients receiving transfusion therapy. We evaluated the efficacy of a photochemical decontamination (PCD) technique using 8-methoxypsoralen (8-MOP) and long wavelength UV light (UVA) to inactivate bacteria in standard therapeutic PC. Twelve phylogenetically distinct pathogenic bacteria, 5 gram-positive and 7 gram-negative organisms, were seeded into PC to a final challenge dose ranging from 10(5) to 10(7) colony- forming units (CFU)/mL. Contaminated PC were treated with 8-MOP (5 micrograms/mL) and 5 J/cm2 of UVA, a PCD treatment regimen found to adequately preserve in vitro platelet function. Greater than 10(5) CFU/mL of all 5 gram-positive (Staphylococcus aureus, Streptococcus epidermidis, Streptococcus pyogenes, Listeria monocytogenes, and Corynebacterium minutissimum) and 2 of the gram-negative (Escherichia coli and Yersinia enterocolitica) organisms were inactivated. The remaining 5 gram-negative organisms were more resistant, with less than 10(1) to 10(3.7) CFU/mL inactivated under these conditions. The inactivation efficiency for this resistant group of gram-negative organisms was improved when PC were resuspended in a synthetic storage medium with reduced plasma protein concentration (15%) and an increased 8-MOP concentration (23.4 micrograms/mL). Illumination with 3 J/cm2 of UVA in this system inactivated greater than 10(5) CFU/mL of 4 resistant gram-negative organisms (Salmonella choleraesuis, Enterobacter cloacae, Serratia marcescens, and Klebsiella pneumoniae) and 10(4.1) CFU/mL of the most resistant gram-negative organism (Pseudomonas aeruginosa). This level of PCD treatment did not adversely affect in vitro platelet function. These results demonstrate that PCD using 8-MOP (5 to 23.4 micrograms/mL) effectively inactivated high levels of pathogenic bacteria in PC with adequate preservation of in vitro platelet properties.

Bacteria in platelet components (PC) may result in transfusion-related sepsis (TRS). Pathogen inactivation of PC with amotosalen (A-PC) can abrogate the risk of TRS and hence facilitate storage to 7 d. A randomized, controlled, double-blinded trial to evaluate the efficacy and safety of A-PC stored for 6-7 d was conducted. Patients were randomized to receive one transfusion of conventional PC (C-PC) or A-PC stored for 6-7 d. The primary endpoint was the 1 h corrected count increment (CCI) with an acceptable inferiority of 30%. Secondary endpoints included 1- and 24-h count increment (CI), 24-h CCI, time to next PC transfusion, red blood cell (RBC) use, bleeding and adverse events. 101 and 100 patients received A-PC or C-PC respectively. The ratio of 1-h CCI (A-PC:C-PC) was 0·87 (95% confidence interval: 0·73, 1·03) demonstrating non-inferiority (P = 0·007), with respective mean 1-h CCIs of 8163 and 9383; mean 1-h CI was not significantly different. Post-transfusion bleeding and RBC use were not significantly different (P = 0·44, P = 0·82 respectively). Median time to the next PC transfusion after study PC was not significantly different between groups: (2·2 vs. 2·3 d, P = 0·72). Storage of A-PCs for 6-7 d had no impact on platelet efficacy.

Photochemical decontamination (PCD) of platelet concentrates, with adequate preservation of platelet function, has been shown using 8- methoxypsoralen (8-MOP) and long wavelength UV light (UVA). To further evaluate this technique, models for the inactivation of pathogenic human cell-associated viruses and integrated proviral sequences are required. We have assessed the ability of the PCD technique to inactivate cell-associated human immunodeficiency virus 1 (HIV-1) in platelet concentrates. We correlated PCD inhibition of HIV-1 infectivity with 8-MOP-DNA adduct formation in contaminating nucleated cells, and measured the inhibition of polymerase chain reaction (PCR)- mediated amplification of cellular DNA sequences as a surrogate for inactivation of integrated proviral nucleic acid sequences. After PCD treatment (8-MOP 300 micrograms/mL, UVA 17 mW/cm2) for 60 minutes, 0.5 x 10(6) plaque-forming units (PFU)/mL of cell-associated HIV-1 were inactivated and no virus was detectable by infectivity assay. After 60 minutes of PCD, 15 8-MOP-DNA adducts per 1,000 bp were formed, while in the absence of UVA, no adducts were formed. PCR-mediated amplification of a 242-bp cellular DNA sequence (HLA-DQ-alpha) was inhibited when greater than eight psoralen-DNA adducts per 1,000 bp were present. These studies indicate that high titers of cell-associated HIV-1 in platelet concentrates were inactivated by PCD, and the numbers of 8-MOP- DNA adducts in nucleated cells were sufficient to inhibit amplification of DNA segments that encode for as few as 80 amino acids. Based on the frequency of 8-MOP-DNA adducts, for the 10-kb HIV-1 genome, the probability of an integrated genome without at least one 8-MOP adduct after 60 minutes of PCD was 10(-33).

This study was conducted to evaluate the safety and efficacy of platelet concentrates (PC) after photochemical treatment (PCT) with the INTERCEPT Blood System™ and transfused in routine use in a population of patients suffering from a variety of hematological diseases. This was an observational, single-arm, open-label study of pooled buffy-coat PC (n = 298) or apheresis PC (n = 262) treated with INTERCEPT™ and transfused to 51 thrombocytopenic hematology patients. PCT replaced CMV screening and gamma irradiation, and made optional bacterial testing obsolete. The primary study endpoint was the incidence of acute transfusion reactions (ATR). Secondary endpoints included bleeding assessment, platelet count increments, and adverse events (AE). For the 553 transfusions, a total of 55 AE were observed regardless of relationship to platelet transfusion. Ten AE associated with nine transfusions met the criteria for ATR (1.6%). All ATRs were grade 1. Twelve serious AE were reported in 10 patients, none was related to platelet transfusion. Mean 24-h CI and CCI were 10.9 × 109 and 6.6 × 103/L, respectively. No bleeding complications were attributable to the INTERCEPT-treated PC. This study confirms safety and efficacy of pathogen inactivated PC for support of thrombocytopenia and demonstrated that INTERCEPT technology can easily be implemented in routine operations.

Amotosalen plus ultraviolet A (UVA) light inactivates a broad range of bacteria, viruses, protozoa, and leukocytes in platelet (PLT) and plasma components. Upon UVA illumination a small fraction of amotosalen reacts with the nucleic acid of contaminating pathogens and residual white blood cells and the remaining fraction undergoes photodegradation into defined photoproducts. The levels of amotosalen and photoproducts can be accurately quantified.This study evaluated the relationship between the extent of photodegradation of amotosalen and the level of pathogen inactivation in PLT components. PLT components containing of 3.78×10(11) to 7.23×10(11) PLTs in 300 to 450 mL of 35% to 50% plasma and 50% to 65% PLT additive solution and up to 5×10(6) red blood cells (RBCs)/mL were prepared. Each component was contaminated with 10(5) to 10(6) colony-forming units/mL Klebsiella pneumoniae and treated with 115 to 200 µmol/L amotosalen and 0 to 3 J/cm2 UVA light. For each treatment condition, the level of K. pneumoniae inactivation (log-reduction) was measured by microbiologic methods. The initial and postillumination amotosalen concentrations (µmol/L) were determined by high-performance liquid chromatography.For a defined set of treatment conditions, the extent of amotosalen photodegradation was consistent and reproducible. The bacterial log-reduction correlated linearly with the extent of amotosalen photodegradation with a regression correlation coefficient (r2) between 0.845 and 0.890 regardless of the treatment variables such as PLT content, component volume, plasma content, RBC content, initial amotosalen concentration, and UVA dose.This study demonstrated that the extent of amotosalen photodegradation can serve as an intrinsic actinometer which directly correlated with the level of pathogen inactivation.

Photochemical pathogen inactivation treatment (PCT) of plasma components with amotosalen and UVA has been implemented in Europe. To establish a postapproval safety database, an active hemovigilance (HV) program utilizing an electronic data capture system (EDCS) was initiated.The response to transfusion was documented after each PCT-plasma transfusion. The primary outcome was the incidence of acute transfusion reactions (ATRs) within 24 hours of transfusion. An ATR was defined as an adverse event (AE) possibly related, probably related, or related to the PCT-plasma transfusion. For AEs, the following were collected: time of event after transfusion, clinical description, vital signs, clinical and laboratory test results, severity (Grade 0-4), seriousness, and causal relationship to transfusion of PCT-plasma.To date, 3232 patients (59.1% male) with a primary indication for plasma transfusion due to a hematology disorder (23.1%), surgery (32.4%), or a general medical condition (44.4%) received 7483 PCT-plasma transfusions (composed of 19,069 apheresis plasma components). The mean age of the patient population was 57.3 years (2884 adults, 160 children, and 188 infants). ATRs were reported for 8/7483 transfusions (0.11%; 95% confidence interval [CI], 0.03-0.19) and 8/3232 patients (0.25%; 95% CI, 0.08-0.42%). Five ATRs were of Grade 1 severity. The remaining three ATRs were classified as serious. No deaths or episodes of transfusion-related acute lung injury attributed to a PCT-plasma transfusion were reported.PCT-plasma transfusions were well tolerated in routine clinical use. The EDCS HV program facilitated collection and reporting of safety information on a real-time basis from multiple sites.

In this paper, we propose the fuzzy group decision making to tackle the rate of aggregative risk in software development. The proposed method is easily implemented and also suitable for only one evaluator.

This paper considers the International Joint Ventures (IJVs) problem using interval-valued fuzzy sets and the compositional rule of inference in the statistical sense. We consider the performance effects of evaluation criteria facts and weights based on fuzzy set theory to determine the performance ranking among IJVs. Due to the lack of precise information based on some fuzzy language is used in the evaluation criterion. We use the statistical confidence-interval estimates and apply the signed distance method to defuzzify.

In this paper, we propose the computational rule inferences to tackle the presumptive rate of aggregative risk in fuzzy circumstances. The proposed method of presumptive rate of aggregative risk directly uses the fuzzy numbers rather than the linguistic values to presume. The presumptive rate is close to the human thinking.

For the total cost of the inventory without backorder model, if we fuzzify the order quantity, the total demand, the cost of storing and the cost of placing an order as fuzzy numbers then we can obtain the fuzzy total cost. In this paper, we apply the signed distance method to defuzzify the fuzzy total cost and then solve the optimal order quantity.

Since the IEEE802.11n is implemented with OFDM (Orthogonal Frequency Division Multiplexing) and MIMO (Multiple Input Multiple Output) techniques, the maximum transmission rate can achieve up to 600 Mbps. As compared with the Mobile Wireless Broadband Technology, the maximum transmission rate of 3.5G (HSDPA) and Mobile WiMAX is apparently insufficient (i.e. less than 4Mbps in the upstream) whereas the IEEE802.11n is primarily adopted in the Fixed Networking Environment (FNE). Therefore, provided that the advantage of IEEE802.11n bandwidth can be endorsed under the Mobile Networking Architecture (MNA), the bandwidth bottleneck of 3.5G (HSDPA) and Mobile WiMAX can be addressed and the differentiated application can be fulfilled in the Mobile Wireless Broadband Industry. In this paper, we propose a new model to analyze the capability of IEEE802.11n operated in the Mobile Networking Architecture. By using this model, we can emulate the vehicular ratio within the signal coverage via the Frequency Emulation Module (FEM) and analyze the capability of TCP/IP under the Multiple Access Point (MAP) mode. According to the result of experiment, the TCP/IP capability of IEEE802.11n is optimal in the low-rate Vehicular Internet Environment (VIE). The capability analysis result proved that the proposed Capability Analysis Model (CAM) of IEEE802.11n not only can be applicable under the Mobile Networking Architecture, but also provide a valuable reference for the Mobile Wireless Broadband Industry.

An evaluation of survey by fuzzy linguistics has been conducted using both the signed distance and centroid method. As to both methods, the proposed approaches, different from conventional survey algorithms via questionnaire rating item by linguistic variables, possessing the vague nature, we employed fuzzy sense of sampling to express the degree of interviewee's feelings based on his own concept, the result will be closer to interviewee's real thought. In this study, we re-model the previous method and use the signed distance method which would be effective and reliable to do aggregated assessment analysis.

BACKGROUND: Pathogen inactivation of platelet (PLT) components (INTERCEPT Blood System, Cerus Europe) was implemented into routine practice at a blood center supporting a tertiary care hospital. Utilization of platelet components (PCs) and red blood cell (RBC) components was analyzed for 3 years before and 3 years after introduction of pathogen inactivation to assess the impact of pathogen inactivation on component use. STUDY DESIGN AND METHODS: This was a retrospective analysis of prospectively collected data. An electronic database used in routine blood bank hemovigilance to monitor production and use of blood components was analyzed to assess clinical outcomes. RESULTS: Transfusion records were analyzed for 688 patients supported with conventional PCs and 795 patients supported with pathogen inactivation PCs. Additional analyses were conducted for intensively transfused hematology patients. Patient demographics (age category, sex, and diagnostic category) were not different in the two observation periods. For all patients, mean numbers of PC per patient were not different for conventional PCs and pathogen inactivation PCs (9.9 +/- 19.5 vs. 10.1 +/- 20.9, p = 0.88). Data for hematology patients (272 conventional PCs and 276 pathogen inactivation PCs) confirmed that days of PLT support were not different (31.6 +/- 42.6 vs. 33.1 +/- 47.9, p = 0.70) nor was total PLT dose (10(11)) per patient (87.3 +/- 115.4 vs. 88.1 +/- 111.6, p = 0.93). RBC use, for all patients and hematology patients, was not different in the two observation periods, either during periods of PLT support or outside periods of PLT transfusion support. CONCLUSION: Pathogen inactivation of PCs had no adverse impact on component use during a 3-year observation period of routine practice.

In this study, we propose a model to do fuzzy aggregative assessment defuzzified by signed distance method. The proposed fuzzy assessment method on sampling survey analysis is easily to assess the sampling survey and make the aggregative evaluation.

This paper focuses on the customer behaviors of Taiwan "Internet Commerce/e-shopping". The member consumption records of A company in 2006 were employed and cross-analyzed to find out the distribution of member variables. We applied RFM model to cluster customers and understand the contribution of each group, and used the decision tree technique, CHAID (Chi-squared Automatic Interaction Detection) to explore member variables and product classifications groups.

In this paper, we present computational rule inferences to tackle the rate of aggregative risk in fuzzy circumstances. Because the proposed assessment method directly uses the fuzzy numbers rather than the linguistic values to evaluate, it can be executed faster than before. The proposed fuzzy assessment method is easier, closer to evaluator real thinking and more useful than the ones they have presented before.

BACKGROUND: Transfusion-transmitted cases of malaria and babesiosis have been well documented. Current efforts to screen out contaminated blood products result in component wastage due to the lack of specific detection methods while donor deferral does not always guarantee safe blood products. This study evaluated the efficacy of a photochemical treatment (PCT) method with amotosalen and long-wavelength ultraviolet light (UVA) to inactivate these agents in red blood cells (RBCs) contaminating platelet (PLT) and plasma components. STUDY DESIGN AND METHODS:Plasmodium falciparum– and Babesia microti–contaminated RBCs seeded into PLT and plasma components were treated with 150 µmol per L amotosalen and 3 J per cm2 UVA. The viability of both pathogens before and after treatment was measured with infectivity assays. Treatment with 150 µmol per L amotosalen and 1 J per cm2 UVA was used to assess the robustness of the PCT system. RESULTS: No viable B. microti was detected in PLTs or plasma after treatment with 150 mol per L amotosalen and 3 J per cm2 UVA, demonstrating a mean inactivation of greater than 5.3 log in PLTs and greater than 5.3 log in plasma. After the same treatment, viable P. falciparum was either absent or below the limit of quantification in three of four replicate experiments both in PLTs and in plasma demonstrating a mean inactivation of at least 6.0 log in PLTs and at least 6.9 log in plasma. Reducing UVA dose to 1 J per cm2 did not significantly affect the level of inactivation. CONCLUSION:P. falciparum and B. microti were highly sensitive to inactivation by PCT. Pathogen inactivation approaches could reduce the risk of transfusion-transmitted parasitic infections and avoid unnecessary donor exclusions.

In this paper, we present weighted triangular fuzzy numbers to tackle the rate of aggregative risk in fuzzy circumstances during any phase of the software development life cycle. Because the proposed assessment method directly uses the fuzzy numbers rather than the linguistic values to evaluate, it can be executed faster than before. The proposed fuzzy assessment method is easier, closer to evaluator real thinking and more useful than the ones they have presented before.

BACKGROUND: A photochemical treatment (PCT) process has been developed to inactivate pathogens and white blood cells (WBCs) in therapeutic plasma. Process validation studies were performed in three European blood centers under routine operating conditions. STUDY DESIGN AND METHODS: Each center prepared 30 apheresis and 30 to 36 whole blood–derived plasma units for PCT. Each whole blood–derived plasma unit contained a mixture of two to three matched donations. After removal of pretreatment control samples (control fresh-frozen plasma [C-FFP]), 546 to 635 mL of plasma was treated with 15 mL of 6 mmol per L amotosalen, 3 J per cm2 UVA treatment, and removal of residual amotosalen with a compound adsorption device. After processing, plasma samples (PCT-FFP) were withdrawn, frozen at −60°C within 8 hours of collection, and assayed for coagulation factors and residual amotosalen. RESULTS: A total of 186 units of plasma were processed. The mean prothrombin time (12.2 ± 0.6 sec) and activated partial thromboplastin time (32.1 ± 3.2 sec) of PCT-FFP were slightly prolonged compared to C-FFP. Fibrinogen and Factor (F)VIII were most sensitive to PCT (26% mean reduction). PCT-FFP, however, retained sufficient levels of fibrinogen (217 ± 43 mg/dL) and FVIII (97 ± 29 IU/dL) for therapeutic plasma. Mean levels of FII, FV, FVII, F IX, FX, FXI, and FXIII in PCT-FFP were comparable to C-FFP (81%-97% retention of activity). Antithrombotic proteins were not significantly affected by PCT with retention ranging between 83 and 97 percent. Mean residual amotosalen levels were 0.6 ± 0.1 μmol per L. CONCLUSION: Process validation studies in three European centers demonstrated retention of coagulation factors in PCT-FFP within the required European and respective national standards for therapeutic plasma.

Traditional sampling survey via questionnaire is difficult in reflecting interviewee's incomplete and uncertain thought. Therefore, if we can use fuzzy sense of sampling to express the degree of interviewee's feelings based on his own concept, the result will be closer to interviewee's real thought. In this study, we propose a model with the linear order character of symmetric fuzzy linguistics for sampling survey to do aggregated assessment analysis. The proposed fuzzy assessment method on sampling survey analysis is easily to assess the sampling survey and make the aggregative evaluation.

BACKGROUND: Photochemical treatment (PCT) with amotosalen and ultraviolet light was developed to inactivate pathogens in platelet (PLT) components suspended in 35 percent plasma and 65 percent additive solution (AS). Because PLT additive solutions (ASs) are not used in the United States, this study evaluated the ability of the PCT process to inactivate low levels of bacteria in pooled whole blood–derived PLTs (RDP) suspended in 100 percent plasma. STUDY DESIGN AND METHODS: Four replicate experiments were performed with two Gram-positive organisms, Staphylococcus epidermidis and Staphylococcus aureus, and two Gram-negative organisms, Klebsiella pneumoniae and Escherichia coli. For each experiment, 6 ABO-identical RDP units were pooled, leukoreduced before or after pooling, inoculated to approximately 1 to 10 colony-forming units per mL with plasma-resistant bacteria, and treated with the PCT process. Residual viable bacterial levels were measured before and after each step and 4 and 6 days after inoculation. For each bacterium studied, a fifth RDP pool was prepared and contaminated, but not treated. These units served as controls for bacterial growth. RESULTS: Growth of S. epidermidis, S. aureus, and K. pneumoniae was eliminated in all four treated pools while growth continued in the control pools. There was no growth of E. coli in the treated pools and the control pool. CONCLUSION: These pilot experiments demonstrate inactivation of bacteria in PLTs suspended in plasma, suggesting that the PCT process may address contamination in conventional RDPs. Additional experiments with a wider range of bacteria and evaluation of PLT function in 100 percent plasma will be needed before implementation.

This paper focuses on the customer behaviors of Taiwan nonstore channels which are "Television Commerce", "Direct Mail and Catalog Marketing", and "Internet Commerce/e-shopping". A survey is conducted to compare consumers' characteristics, motivations and differentiated between the stages of the buying process and behavior among those three channels. Finally, the results and suggestions are stated as an important reference for nonstore retailers while developing the marketing strategies.

Information techniques have brought us tremendous benefit, whereas people are increasingly depended on lots of information systems. Therefore, how to establish an assessment model to choose a better software quality suitable for end-users is an important issue. This study presents a new assessment method to obtain the integrated software quality for evaluating user satisfaction using fuzzy set theory. The proposed fuzzy assessment method is easier, closer to evaluator real thinking and more useful than the ones they have presented before.

Spatial equilibrium model is a method of measurement that is designed to analyze the structure of competition of various products in the region to find both the quantity and price of equilibrium supply and demand as well as optimal routes. However, there is not much literature focusing on international trade related topics and even less researches by introducing tariff into the model. The reason is that most of products are levied importing tariff on the basis of compound duty that is composed of ad Vol Orem duty and unit duty and it hence is difficult to introduce such tariff system into spatial equilibrium model. Thus, the paper is mainly to construct a spatial equilibrium model of international trade in an imperfectly competitive market.

BACKGROUND: This study compared the efficacy of bacterial detection with inactivation for reducing the risk associated with transfusion of platelet (PLT) components contaminated with low levels of bacteria. STUDY DESIGN AND METHODS: Twenty-one double-dose PLTs were spiked with seven species of bacteria at three levels (0.003-0.03, 0.03-0.3, 0.3-3 colony-forming units [CFUs]/mL). After split, each PLT unit contained 1 to 10, 10 to 100, and 100 to 1000 CFUs. One unit was photochemically treated (PCT; 150 µmol/L amotosalen and 3 J/cm2 ultraviolet A). The other unit was untreated. All units were stored and sampled on Days 1, 2, and 5 of storage for aerobic and anaerobic culture in the BacT/ALERT system (bioMerieux). PLTs were classified as sterile when no bacterial growth was detected after 120 hours of culture. RESULTS: In all PCT PLTs, no bacteria were detected throughout 5 days of storage regardless of species, level of contamination, and sampling time. In untreated PLTs, Staphylococcus aureus was consistently detected by culturing. Growth of 1 to 10 CFUs per unit Staphylococcus epidermidis, 1 to 100 CFUs per unit of Klebsiella pneumoniae, and 1 to 1000 CFUs per unit Propionibacterium acnes was delayed and only detectable after 5, 2, and 5 days of storage, respectively. Low levels of Streptococcus agalactiae (1-10 CFUs/unit), Escherichia coli (1-100 CFUs/unit), and Clostridium perfringens (1-100 CFUs/unit) were not detected during 5 days of storage, although bacterial outgrowth was detected at higher levels of contamination. CONCLUSIONS: For the seven bacterial species examined, contaminated PLTs may be released for transfusion on test-negative-to-date status. In contrast, bacterial inactivation by PCT could reduce the risk associated with transfusion of PLTs contaminated with low levels of these bacteria.

This study evaluated the efficacy of photochemical treatment (PCT) with amotosalen and ultraviolet A (UVA) light to inactivate Trypanosoma cruzi in contaminated platelet (PLT) components.Fifteen pools of buffy-coat PLTs (BC-PLTs) were inoculated with approximately 5 x 10(3) to 5 x 10(5) per mL of viable T. cruzi of the G, Tulahuen (T), or Y strains. Samples from BC-PLTs were assayed for infectivity before and after PCT with 150 micromol per L amotosalen and 3 J per cm(2) UVA light. Infectivity was determined with three different methods: 1) in vitro culture to detect viable epimastigotes, 2) [(3)H]thymidine incorporation in culture, and 3) in vivo inoculation into interferon-gamma receptor (IFN-gammaR)-deficient mice.The in vitro assay yielded viable parasite titers of 3.9 x 10(5), 2.8 x 10(4), and 5.6 x 10(3) per mL (corresponding to 5.6, 4.4, and 3.8 logs/mL) for the Y, T, and G strains, respectively. PCT was able to inactivate all three strains of T. cruzi to below the limit of detection (10 parasites/mL) in the sensitive in vivo assay. Because 10-mL samples, each concentrated into a 1-mL sample for inoculation, were tested in the in vivo assay, log reductions achieved were greater than 5.6, greater than 4.4, and greater than 3.8 for the Y, T, and G strains of T. cruzi, respectively.The pathogen reduction system with amotosalen HCl and UVA demonstrated robust efficacy for inactivation of high doses of three different strains of T. cruzi and offers the potential to make the PLT supply safer.