New Blood Test Can Show Past, Present Viral Infections
A new technology developed by Howard Hughes Medical Institute (HHMI) could allow a single test to determine an individual's past and present viral infections, compared to current assays that only test for specific viruses at a time.
Called VirScan, the method works by screening the blood for antibodies against any of the 206 viral species known to infect humans. Stephen Elledge, PhD, of Brigham and Women's Hospital in Boston, MA, and colleagues synthesized over 93,000 short DNA pieces encoding various segments of viral proteins; these DNA pieces were introduced into bacteriophage that manufactured peptide and displayed them on its surface. Together the bacteriophage displayed all of the peptides found in the over 1,000 known strains of human viruses. In the VirScan analysis, all of the peptide-displaying bacteriophage mingle with a blood sample so that antiviral antibodies in the blood can find and target epitopes within the displayed peptides.
VirScan was tested using blood samples from patients known to be infected with particular viruses, including HIV and hepatitis C; the test had sensitivity of 95–100% with good specificity. No false positives were detected. It was also used to analyze antibodies from 569 people in four countries to evaluate its efficacy for approximately 100 million potential antibody/epitope interactions.
Although the VirScan only tests for antiviral antibodies, the technology is being applied to test for other antibodies that attack body tissue in certain autoimmune diseases associated with cancer. It could also be used to screen for antibodies against other types of pathogens.
For more information visit HHMI.org.