By Richard Harth
An inexpensive system for earlier disease diagnosis could save innumerable lives. It would also have a profound impact on the nation’s healthcare industry, currently buckling under the strain of spiraling costs.
Now Dr. Bart Legutki, a researcher at the Biodesign Institute at Arizona State University has pioneered a method for profiling the immune system, using clues provided by antibody activity to track an individual’s state of health. The work was done in collaboration with Dr. Stephen Albert Johnston, director of the Institute’s Center for Innovations in Medicine.
The new technique, known as immunosignaturing, could provide rapid, pre-symptomatic diagnosis for a broad range of ailments, from infectious diseases to chronic afflictions to varied forms of cancer, offering the best hope for successful treatment. Immunosignaturing also shows potential as a low-cost alternative for vaccine evaluation, currently a lengthy and expensive undertaking.
As Legutki explains, the immune system is exquisitely sensitive to any alterations in an individual’s state of health resulting from infection or disease, registering these changes through subtle fluctuations in antibody activity. “The body has already done the hard work of figuring out what is going on inside us,” he says, adding, “We just need to interpret the message.”
The immunosignature can be thought of as a snapshot of an individual’s immune system activity at the point in time the test is taken. The test involves a tiny sample of blood that is spread across a slide, with a resulting image that appears as a pattern of colored spots. The team demonstrated that a baseline immunosignature of antibody activity could be established and then compared with an immunosignature following exposure to a vaccine or pathogen.
In the current study, a distinctive shift in the immunosignature pattern was observed in both mice and humans, following vaccination for influenza. Further, the picture of activity appeared to be pathogen-specific—the immunosignature for influenza displayed a characteristic pattern easily distinguishable from that produced by tularemia exposure. The group’s findings recently appeared in the journal Vaccine.
Johnston notes that most existing diagnostic blood tests used to evaluate host-pathogen response target a single disease component. “With traditional tests, you're only analyzing the immune response to very defined things,” he says. This is true for example with ELISA, one of the most popular tests, which looks at an antigen or collection of antigens extracted from a whole virus or other pathogen. Once the antigen has been isolated, it is spread out on a slide and exposed to a sample of blood—generally several micro liters. ELISA and similar immunoassays test antibodies one by one and generally require the pathogen of interest to be known in advance.
