Retention of coagulation factor activity after PCT was expressed as the proportion of pretreatment (baseline) activity. 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. Plasma function was evaluated through measurement of coagulation factors and antithrombotic protein activities. The viability of each pathogen before and after treatment was measured with biological assays. Jumbo (600 mL) plasma units were inoculated with high titers of test pathogens and treated with 150 micromol per L amotosalen and 3 J per cm(2) long-wavelength ultraviolet light. These studies evaluated the efficacy of PCT to inactivate pathogens in plasma and the effect of PCT on plasma function. The INTERCEPT Blood System, a photochemical treatment (PCT) process, has been developed to inactivate pathogens in platelet concentrates. Inactivation of viruses in PLT concentrates with amotosalen and UVA offers the potential to prospectively prevent the majority of PLT transfusion-associated viral diseases. PCT inactivates a broad spectrum of pathogenic, blood-borne viruses. 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. 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.
After PCT with 150 micromol per L amotosalen and 3 J per cm(2) UVA, residual viral infectivity was assayed by sensitive cell culture or animal systems.Įnveloped viruses were uniformly sensitive to inactivation by PCT whereas nonenveloped viruses demonstrated variable inactivation. High titers of pathogenic or blood-borne viruses, representing 10 different families, were added to single-donor PLT concentrates containing 3.0 x 10(11) to 6.0 x 10(11) PLTs in approximately 300 mL of 35 percent plasma and 65 percent PLT additive solution (InterSol). 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. Viral contamination of platelet (PLT) concentrates can result in transfusion-transmitted diseases.
#Bv4 torchat may not be safe full
In the future, if the full inventory of transfusable components can be effectively pathogen-inactivated, PI could form an alternative basis for blood safety in terms of microbial risk, rather than just another incremental safety intervention. Pathogen inactivation (PI) offers an approach to remove the vast majority of microbial risks. Parasitic and, even more significantly, bacterial risks (especially in platelet preparations which have to be stored at 22 degreesC) have often not been managed as effectively as the risk for the 'known' viruses such as HIV, HBV and HCV. However, newly emergent viral risks can usually only be addressed after they have been shown to transmit and after tests have been developed. A wide range of sophisticated (and resource-consuming) interventions are in place which are generally successful in dealing with the risk from known viral agents. Although the blood supply in developed countries is now very safe, residual microbial risks can still be identified.
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