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BACKGROUND: 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. STUDY DESIGN AND METHODS: 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 × 1011 to 7.23 × 1011 PLTs in 300 to 450 mL of 35% to 50% plasma and 50% to 65% PLT additive solution and up to 5 × 106 red blood cells (RBCs)/mL were prepared. Each component was contaminated with 105 to 106 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. RESULTS: 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. CONCLUSION: This study demonstrated that the extent of amotosalen photodegradation can serve as an intrinsic actinometer which directly correlated with the level of pathogen inactivation.

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: 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.

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: 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.

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.

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.

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.

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.

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.

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.

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.

BACKGROUND: The INTERCEPT Blood System (Baxter Healthcare Corp.) for platelets (PLTs) uses amotosalen-HCl (S-59) in conjunction with ultraviolet A (UVA) light to inactivate contaminating pathogens by modifying the nucleic acids of pathogens. The success of this photochemical treatment (PCT) process can be documented indirectly with a high-performance liquid chromatography assay measuring the photodegradation of amotosalen and measurement of the UVA light dose delivered by the illumination system. STUDY DESIGN AND METHODS: To develop an assay that documents the success of PCT directly on the effector molecule DNA, the effect of PCT on PLT-derived mitochondrial DNA (mtDNA) was examined. mtDNA-specific polymerase chain reaction (PCR) assays were tested with regard to their susceptibility for PCT, their reliability in terms of PCR performance, and the absence of polymorphic sites in primer hybridization loci. RESULTS: Suitable PCR amplification targets were found in the regions of 16S rDNA, cytochrome c oxidase I, and cytochrome c oxidase III of mitochondria. Amplicon sizes between 868 and 1248 bp gave consistent signals before PCT and complete inhibition of the PCR signal after PCT. Amplicons of less than 300 bp were found to be transparent to PCT. CONCLUSION: Based on PCT-mediated mtDNA modifications in PLTs, a PCR inhibition assay was established with a large amplicon documenting the success of PCT and a small amplicon serving as an internal control.

BACKGROUND: This multicenter, randomized, controlled, double-blind Phase III clinical study evaluated the therapeutic efficacy and safety of apheresis platelets (PLTs) photochemically treated (PCT) with amotosalen and ultraviolet A light (INTERCEPT Blood System, Baxter Healthcare Corp.) compared with conventional apheresis PLTs (reference). STUDY DESIGN AND METHODS: Forty-three patients with transfusion-dependent thrombocytopenia were randomly assigned to receive either PCT or reference PLT transfusions for up to 28 days. RESULTS: The mean 1- and 24-hour corrected count increments were lower in response to PCT PLTs (not significant). When analyzed by longitudinal regression analysis, the estimated effect of treatment on 1-hour PLT count was a decrease of 7.2 × 109 per L (p = 0.05) and on 24-hour PLT count a decrease of 7.4 × 109 per L (p = 0.04). Number, frequency, and dose of PLT transfusions; acute transfusion reactions; and adverse events were similar between the two groups. There was no transfusion-associated bacteremia. Four PCT patients experienced clinical refractoriness; however, only one exhibited lymphocytotoxicity assay seroconversion. Antibodies against potential amotosalen-related neoantigens were not detected. CONCLUSION: PCT PLTs provide effective and safe transfusion support for thrombocytopenic patients.

BACKGROUND: Viral contamination of platelet (PLT) concentrates can result in transfusion-transmitted diseases. A photochemical treatment (PCT) process with amotosalen-HCl and long-wavelength ultraviolet light (UVA), which cross-links nucleic acids, was developed to inactivate viruses and other pathogens in PLT concentrates. STUDY DESIGN AND METHODS: High titers of pathogenic or blood-borne viruses, representing 10 different families, 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). After PCT with 150 µmol per L amotosalen and 3 J per cm2 UVA, residual viral infectivity was assayed by sensitive cell culture or animal systems. RESULTS: Enveloped viruses were uniformly sensitive to inactivation by PCT whereas nonenveloped viruses demonstrated variable inactivation. Log reduction of enveloped viruses for cell-free HIV-1 was >6.2; for cell-associated HIV-1, >6.1; for clinical isolate HIV-1, >3.4; for clinical isolate HIV-2, >2.5; for HBV, >5.5; for HCV, >4.5; for DHBV, >6.2; for BVDV, >6.0; for HTLV-I, 4.2; for HTLV-II, 4.6; for CMV, >5.9; for WNV, >5.5; for SARS-HCoV, >5.8; and for vaccinia virus, >4.7. Log reduction of nonenveloped viruses for human adenovirus 5 was >5.2; for parvovirus B19, 3.5->5.0; for bluetongue virus, 5.6-5.9; for feline conjunctivitis virus, 1.7-2.4; and for simian adenovirus 15, 0.7-2.3. CONCLUSION: PCT inactivates a broad spectrum of pathogenic, blood-borne viruses. Inactivation of viruses in PLT concentrates with amotosalen and UVA offers the potential to prospectively prevent the majority of PLT transfusion-associated viral diseases.

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.Three sequential clinical trials evaluated viability of PCT platelets prepared with a prototype device. Posttransfusion recovery and lifespan of (111)Indium-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.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% (p0.01). Mean lifespan for PCT-CAD platelets was 4.8 days (+/-1.3) versus 6.0 days (+/-1.2) for control platelets, mean difference of 1.3 days (p0.01). Platelet recovery and lifespan were similar to PCT-CAD for PCT without CAD treatment and PCT-CAD with gamma-irradiation.Viability of 5 day-old PCT platelets was less than for control platelets. However, both were within ranges reported for 5 day-old platelets.

Background A photochemical treatment process has been developed for the inactivation of viruses and bacteria in platelet concentrates. This process is based on the photochemical reaction of a novel psoralen, S-59, with nucleic acids upon illumination with long-wavelength ultraviolet light (UVA, 320-400 nm). Study design and methods High levels of pathogens were added to single-donor platelet concentrates containing 3 to 5 x 10(11) platelets in 300 mL of 35-percent autologous plasma and 65-percent platelet additive solution. After treatment with S-59 (150 microM) and UVA (0-3 J/cm2), the infectivity of each pathogen was measured with established biologic assays. In vitro platelet function after photochemical treatment was evaluated during 7 days of storage by using a panel of 14 assays. The in vivo recovery and life span of photochemically treated platelets were evaluated after 24 hours of storage in a primate transfusion model. Results The following levels of pathogen inactivation were achieved: >10(6.7) plaque-forming units (PFU) per mL of cell-free human immunodeficiency virus (HIV), >10(6.6) PFU per mL of cell-associated HIV, >10(6.8) infectious dose (ID50) per mL of duck hepatitis B virus (a model for hepatitis B virus), >10(6.5) PFU per mL of bovine viral diarrhea virus (a model for hepatitis C virus), >10(6.6) colony-forming units of Staphylococcus epidermidis, and >10(5.6) colony-forming units of Klebsiella pneumoniae. Expression of integrated HIV was inhibited by 0.1 microM S-59 and 1 J per cm2 of UVA. In vitro and in vivo platelet function were adequately maintained after antiviral and antibacterial treatment. Conclusion Photochemical treatment of platelet concentrates offers the potential for reducing transfusion-related viral and bacterial diseases.

BACKGROUND: Pathogen inactivation of plasma intended for transfusion is now the standard of care in Belgium. Two methods for treatment of single plasma units are available: amotosalen plus ultraviolet A light and methylene blue plus visible light. This study compared the quality and stability of plasma treated with these two methods. STUDY DESIGN AND METHODS: Plasma units made from a pool of two ABO-matched fresh apheresis units were photochemically treated with either amotosalen (PCT-FFP) or methylene blue (MB-FFP). A total of 12 paired samples were evaluated. Plasma coagulation function was assessed at three time points: immediately after treatment, after 30 days of frozen storage, and an additional 24 hours at 4 degrees C after thawing. Comparison between PCT-FFP and MB-FFP was assessed with the paired t test and a p value of less than 0.05 indicated statistical significance. RESULTS: Based on statistical analysis, mean levels of factor (F)II, FXII, FXIII, von Willebrand antigen, ADAMTS-13, D-dimers, and protein C were equivalent between PCT-FFP and MB-FFP for all three time points. PCT-FFP exhibited shorter mean prothrombin time, activated partial thromboplastin time (two time points), and thrombin time and higher mean levels of fibrinogen, FXI, and protein S than MB-FFP. Retention of FV, FVII, FVIII, FX, or von Willebrand factor:ristocetin cofactor in PCT-FFP was either equivalent to or higher than MB-FFP. MB-FFP contained higher mean levels of plasminogen, antithrombin, and plasmin inhibitor than PCT-FFP. Retention of F IX in MB-FFP was higher than PCT-FFP only after the 4 degrees C storage after thawing. CONCLUSION: There is adequate preservation of therapeutic coagulation factor activities in both PCT-FFP and MB-FFP. The overall coagulation factor levels and stability of PCT-FFP were better preserved than MB-FFP.