Researchers at the University of Wisconsin-Madison (UW) have identified neutrophil cell function in a single drop of blood as a way to accurately diagnosis asthma.

Investigators with the study used kit-on-a-lid-assay (KOALA) microfluidic technology developed by UW to identify the previously unknown correlation between asthmatic patients and the body’s abundant supply of neutrophil white blood cells. Their findings may enable doctors to diagnose asthma, even if a patient is not experiencing symptoms at the time of the visit, UW reports.

The findings were published online in Proceedings of the National Academy of Sciences (PNAS).

“What we’ve done in this paper is presented data that neutrophil cell function in some cases can predict whether someone is asthmatic or not,” said David Beebe, a UW-Madison professor of biomedical engineering and co-author on the paper. “This is one of the first studies to show that this process could actually work in a cheap, easy and practical way.”

For the study, Beebe and his team focused on the cell function of neutrophils – the most abundant white blood cell in the body. These cells generally are the first 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 added.

To more efficiently analyze the cells, UW-Madison students developed the KOALA microfluidic technology that can detect neutrophils movement using a single drop of blood. The blood sample is placed on a small plastic lid and added to a base coated with a chemical mixture. The chemical mixture triggers neutrophil migration, enabling researchers to track and analyze the neutrophil chemotaxis velocity using custom software.

“Right now, asthma diagnosis is based on indirect measures,” Beebe says, “which is not optimal. So the premise in this paper was that cell function could be used to diagnose asthma, and that we could measure cell function in way that was simple and cheap enough to be used clinically.”