Now, faster, cheaper blood test to accurately diagnose asthma

Researchers have developed a faster, cheaper and more accurate tool for diagnosing even mild cases of asthma using just a single drop of blood.

The researchers used neutrophil cell function in a clinical study to show accurate asthma diagnosis.

To directly diagnose asthma, David Beebe, a UW-Madison professor of biomedical engineering and co-author on the paper, and his team focused on the cell function of neutrophils. Neutrophils are the most abundant white blood cell in the body and generally are the first cells to migrate toward inflammation.

"Neutrophils are sort of like a dog tracking something. They sense a chemical gradient, like an odor, in the body," Beebe says.

In other words, the human body emits chemical signals in response to inflammation or wounds and the neutrophils detect those chemical signals and migrate to the site of the wound to aid in the healing process. Researchers can track the velocity at which the neutrophil cells migrate - the chemotaxis velocity - to differentiate nonasthmatic samples from the significantly reduced chemotaxis velocity of asthmatic patients.

UW-Madison students have developed the kit-on-a-lid-assay (KOALA) microfluidic technology, which allows them to detect neutrophils using just a single drop of blood.

The KOALA diagnostic procedure uses simple lids and bases (each being a small, cheap piece of plastic), diagnosticians place a KOALA lid containing a chemical mixture onto the base containing the blood sample. That chemical mixture triggers neutrophil migration - and researchers can automatically track and analyze the neutrophil chemotaxis velocity using custom software.

The team has published online in the journal Proceedings of the National Academy of Sciences.