Scientists develop new approach for detecting early-stage asthma

Microfluidic technology characterizes asthma from a drop of blood using neutrophil chemotaxis.

Researchers at the University of Wisconsin–Madison (WI, USA), in collaboration with the Wisconsin Institutes for Medical Research (WI, USA), have reported on neutrophil chemotaxis velocity as a potential biomarker for asthma, and have demonstrated a new microfluidic technology that may be used to perform these measurements.

The handheld diagnostic device sorts neutrophils from whole blood within 5 min, and generates a gradient of chemoattractant in the microchannels by placing a lid with chemoattractant on to the base of the device. According to the report, the technology was applied in a clinical setting to assay 34 asthmatic and nonasthmatic, allergic rhinitis patients to establish domains for asthma diagnosis based on neutrophil chemotaxis.

The team discovered that neutrophils from asthmatic patients migrate significantly more slowly toward the chemoattractant compared with nonasthmatic patients. Analysis of the receiver operator characteristics of the patient data revealed that using a chemotaxis velocity of 1.55 μm/min for asthma yields a diagnostic sensitivity and specificity of 96% and 73%, respectively.

David Beebe, a researcher at University of Wisconsin–Madison and co-lead author of the study, envisages that the technology has the potential to measure cell function in a way that is simple and cheap enough to be used clinically.

Source: Sackmann EK, Berthier E, Schwantes EA et al. Characterizing asthma from a drop of blood using neutrophil chemotaxis. Proc. Natl Acad. Sci. USA doi:10.1073/pnas.1324043111 (2014) (Epub ahead of print).