Diagnosing complex diseases like cancer requires a dizzying array of expensive, often inconclusive and sometimes painful tests--biopsies into deeply rooted tumors or repeated brain scans that often aren't sensitive enough to pick up subtle changes that hint at abnormalities.
But what if all that information--the molecules that contribute to Alzheimer's, for example, or the antibodies that appear after nerves die in a Parkinson's patient--could be gleaned from a few drops of blood? That's the reality being engineered at institutions around the U.S., where researchers are parsing gases, hormones, nutrients, antibodies and other blood components to find potentially lifesaving information. Within a few years, clinical trials could yield tests for the masses.
One major goal: make detection cheaper and faster than more invasive procedures--which could help some patients take preventive measures or start treatments earlier. And for brain conditions such as Alzheimer's (in living patients), autism and depression, which currently can't be diagnosed definitively, these blood tests could help make diagnoses much more accurate.
Measuring blood's biomarkers, or disease indicators, with enough precision to diagnose diseases accurately will take more trial and error. But "we have come a long way," says Dr. Kristine Yaffe of the University of California, San Francisco, who is developing blood tests to scan for Alzheimer's. "There is a lot of potential."