VirScan Reveals Viral History from a Single Drop of Blood
Researchers have developed a test that uses a single drop of blood to determine which of more than 1,000 different viruses currently infects or previously infected a person.
Using the new method, known as VirScan, researchers from Brigham and Women’s Hospital (BWH) and Harvard Medical School detected an average of 10 viral species per person during their study. The findings, published in Science (June 5, 2015), shed light on the relationship between the vast array of viruses that can infect humans (the human virome) and a person’s immunity. This insight, in turn, has significant implications for our understanding of immunology and patient care.
The research team found the sensitivity and precision of VirScan to be very similar to that of today’s standard blood tests. However, today’s standard blood tests can detect only one pathogen at a time and have not been developed to detect all viruses.
VirScan, on the other hand, can detect any of the virus types that are known to affect humans – and check for all of them at the same time. It does this by screening blood for virus-specific antibodies that are produced during an immune response, which the body continues to produce for decades afterward.
“VirScan is a little like looking back in time,” says study author Stephen Elledge, PhD, a Principal Investigator in the Division of Genetics at BWH and Gregor Mendel Professor of Genetics and Medicine at Harvard Medical School. “Using this method, we can take a tiny drop of blood and determine what viruses a person has been infected with over the course of many years. What makes this so unique is the scale. Right now, a physician needs to guess what virus might be at play and individually test for it. With VirScan, we can look for virtually all viruses, even rare ones, with a single test.”
Scientists are now pondering the impact of being able to determine a person’s viral history. There are, for example, many diseases that are believed to be triggered by viral infections. The new test could help to confirm these links and to discover new links, which could spur the development of new treatments. It also could be used to screen for infections before symptoms appear, thereby enabling patients to reap the benefits of early intervention.
“A viral infection can leave behind an indelible footprint on the immune system,” says Elledge. “Having a simple, reproducible method like VirScan may help us generate new hypotheses and understand the interplay between the virome and the host’s immune system, with implications for a variety of diseases.”