Toward diagnosing diseases such as cancer in their earliest stages

In response to a wide range of conditions, including cancer, viral infections and autoimmune disorders, the body's immune system produces proteins called antibodies. Identifying specific antibodies can help physicians make accurate diagnoses. However, levels of these proteins are low at early disease stages, so it is difficult to detect them with methods currently approved by the U.S. Food and Drug Administration (FDA). Also, some of these tests involve hazardous radioactive materials and specialized facilities, making them expensive to carry out. Carolyn R. Bertozzi and colleagues wanted to come up with a simpler, more accessible approach that could detect low concentrations of these proteins.

The researchers developed a new way to detect antibodies in a fraction of a drop of blood with common lab equipment. Testing it with patient samples showed that the method, called antibody detection by agglutination-PCR or ADAP, was 1,000 times more sensitive in detecting thyroid cancer antibodies than the radioimmunoassays that are the current gold standard. The researchers say ADAP could also be designed to look for antibodies in saliva.