Breath Test Measures Immune Response to H1N1 Virus

A novel breath test detects people who have an immune response to the Influenza A virus strain H1N1. The test would help to ease future vaccine shortages by identifying the people who have already been infected with the flu virus.

In a study, published July 15, 2011, in IOP Publishing's Journal of Breath Research, scientists investigated the easy, noninvasive breath test to measure biomolecules that accumulate in response to the H1N1 strain of the flu virus.

Investigators from Cleveland Clinic (Ohio, USA) and Syft Technologies (Christchurch, New Zealand) included 11 individuals in their study. Nine of these participants were given the live attenuated H1N1 vaccine via a nasal spray and the breath test was administered on each of the following seven days.

Samples of exhaled NO were provided by six participants prior to vaccination. Nitric oxide is a test approved by the US Food and Drug Administration (FDA; Silver Spring, MD, USA) for monitoring inflammation and asthma. Production of exhaled nitric oxide (NO) has also been linked to influenza and viral infection.

The breath test examined exhaled nitric oxide (NO)--a biomolecule whose production has previously been linked to influenza and viral infection and has been speculated to play a beneficial role in viral clearance.

The results showed a peak in NO levels in all subjects on the third day after vaccination. There were no significant differences in NO levels on any other day.

Of the 11 other compounds examined in the study, only one compound–isoprene–showed an elevated level, also on day three. Increased levels of isoprene, a compound produced within the body and a major constituent of exhaled breath, have been reported to reflect oxidative stress in airways.

Previous findings show that the highest number, and severity, of symptoms related to a H1N1 infection occur on day three, suggesting, along with this study, that this is when an immune response is triggered in the body.

A breath test, measuring the immune response to the H1N1 flu virus, could help to ease future vaccine shortages by identifying the people who have already been infected with the flu virus.

Study coauthor Dr. Raed Dweik, professor of medicine and director of the pulmonary vascular program at the Cleveland Clinic, said when the H1N1 epidemic occurred in 2009 physicians were faced with a dilemma related to patient treatment.

"We all have nitric oxide in our breath because our lungs make it, but with different levels," said Prof. Dweik. "If you have an infection or an inflammation or if you have asthma, it goes up."

Prof. Dweik cautions that while the work is "rather preliminary," he sees it as proof of the concept that breath can be used to monitor the vaccination and, it is hoped, the infection.

Related Links:
Cleveland Clinic
Syft Technologies
US Food and Drug Administration