Five-Minute Kit-on-a-Lid Assay Detects Asthma from Whole Blood

A team of bioengineers has developed a simple, hand-held device that enables diagnosis of asthma from a single drop of blood.

The "kit-on-a-lid-assay (KOALA)" microfluidic technology used to perform the test is the brain child of investigators at the University of Wisconsin (Madison, USA). KOALA capitalizes on differences in neutrophil function to discriminate asthma from allergic rhinitis. Neutrophils are inflammatory immune system cells that have been implicated in the pathogenesis of asthma.

The handheld KOALA device sorts neutrophils from whole blood within five minutes due to a gradient of chemoattractant that is generated in the device's microchannels when a lid with chemoattractant is placed onto the base of the device.

KOALA technology was used in a clinical setting to assay 34 asthmatic (n=23) and nonasthmatic, allergic rhinitis (n=11) patients to establish domains for asthma diagnosis based on neutrophil chemotaxis. The investigators determined that neutrophils from asthmatic patients migrated significantly more slowly toward the chemoattractant compared with nonasthmatic patients.

“What we have done in this paper is presented data that neutrophil cell function in some cases can predict — and in this case actually predicted and measured — whether someone is asthmatic or not,” said senior author Dr. David Beebe, professor of biomedical engineering at the University of Wisconsin. “This is one of the first studies to show that this process could actually work in a cheap, easy, and practical way.”

“The KOALA platform represents the next-generation biomedical research kit,” said Dr. Beebe. “Instead of getting a box of media and staining solution and having to do a lot of manual manipulation, you would get the base for the fluid sample, the prepackaged KOALA lids, and to do any testing, just place a lid (or series of lids) on the base.”

The study describing the use of KOALA was published in the April 7, 2014, online edition of the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).

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