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| |  New Blood Screening Method Being Evaluated CULVER CITY, Calif., June 18, 1997 -- National Genetics Institute has started the first clinical study of its proprietary nucleic acid amplification technology based on robotics and the Polymerase Chain Reaction (PCR) testing method, to determine its ability to screen pooled samples of donated human plasma for the presence of the HIV-1 and HIV-2 and Hepatitis C Virus (HCV). The PCR test is highly sensitive and may have the potential to detect the presence of HIV or HCV sooner than traditional antigen and antibody tests, said Andrew Conrad, Ph.D., Director, Research and Development of NGI. By detecting the presence of the virus itself, the PCR test may be able to reduce the window period, during which a virus may be present and transmissible but detectable antibodies to the virus have not yet formed and may be useful in addition to tests for HIV antigen. Donations of human plasma are currently tested for antibodies to HIV and HCV, Hepatitis B surface antigen and HIV antigen, among others. Through a process called fractionation, plasma is separated into its individual components and purified into different products. More than three million people each year in the United States receive plasma derived products, which include those to treat people with hemophilia and immune disorders as well as shock and burn victims. NGI filed an Investigational New Drug (IND) application with the U.S. Food and Drug Administration (FDA) on February 20, 1997. NGI began the clinical trial in conjunction with its lead principal investigators, Alpha Therapeutic Corporation, a leading plasma fractionator and the American Red Cross (ARC), supplier of approximately half of the nation's blood supply. The first phase of the plasma pool trial will involve Alpha's collection of approximately 300,000 samples from plasma donations at its centers across the country. Samples will be pooled at Alpha's laboratory in Memphis, Tennessee and will be shipped to NGI for testing. Alpha will compile and analyze the data, including tracking reactive samples back to the individual donors for the purpose of validating this test as a donor screen. The second phase will include tracking patients with reactive results for HIV and HCV. One purpose of this tracking, besides notifying donors of infection and their deferral, is to establish the length of time between detection of a virus by PCR and seroconversion, or the development of antibodies. This information is important for the validation of the assay. The ARC will collect up to 300,000 whole blood donations from its blood centers throughout the country. Samples will be collected in a special tube containing nucleic acid preservative to ensure the best possible conditions for testing. This study will track donors reactive by PCR for HIV and HCV RNA. According to Susan Stramer, Ph.D., Director, Confirmatory Testing Laboratory for the ARC, the company’s studies suggest that the HIV window period when the virus is present but the current HIV antigen test is negative (which is estimated at six days) may be reduced by approximately two days with RNA-PCR testing. The company’s clinical tests, she added, will evaluate whether the HCV window period, which is estimated at 41 days, could be reduced further by 20 to 40 days with PCR testing. Currently there are no licensed PCR testing methods for screening plasma for HIV-1, HIV-2 and HCV. PCR testing by NGI is performed pursuant to a license agreement with Roche Molecular Systems, Inc. In addition to screening plasma for fractionation, NGI pioneered the use of PCR in testing plasma products in their final containers. Beginning in 1996, NGI has tested samples of all Alpha released plasma products, including analysis for HIV, HCV and Hepatitis B Virus (HBV) and Hepatitis A Virus (HAV).
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