Scientists have developed a handheld diagnostic device that can help distinguish between asthma and allergic rhinitis by monitoring the velocity of neutrophil migration towards chemoattractants.

As most of us enjoy the unusually pleasant spring here in Germany, a small but a significant number of the population is probably suffering from adverse reactions to allergens that one can associate with the warmer weather and trees in full bloom - such seasonal reactions to specific allergens are not uncommon.

For a person with asthma, a chronic disease that causes severe inflammation in the lungs, in addition to allergens, factors like physical exercise and extreme emotions can even trigger an episode of breathlessness and wheezing – the severity of these attacks varies from individuals. The key factors that discriminate hay fever from asthma are the actual symptoms exhibited by the patients. Physicians often use medical history and a series of tests to diagnose asthma.

In a research article published in the PNAS, Sackmann et al. (2014) describe how a drop of blood could be sufficient to determine if a patient suffers from asthma or not. By improvising on their previously engineered device that helps sort neutrophils from blood and assess chemotaxis, the researchers studied the neutrophils from the blood of asthmatic, nonasthmatic and allergic rhinitis patients, and observed a marked decrease in the speed with which neutrophils from asthmatic individuals migrate. The researchers thus propose the velocity of neutrophil chemotaxis as a biomarker for asthma diagnosis.

The full-text article titled ‘Characterizing asthma from a drop of blood using neutrophil chemotaxis’ and authored by Sackmann et al. can be obtained from http://www.pnas.org/cgi/content/long/1324043111v1