Filenews 9 November 2021
On November 2, 2021, the study of a team of the University of Ohio in the USA entitled "The detection of exhaled nitric oxide can diagnose patients suffering from severe COVID-19" was published in the prestigious scientific journal PLOS ONE.
This is a test equivalent to the alcohol test, which diagnoses COVID-19 with relatively high accuracy, although at the moment it does not seem to be completely comparable, in terms of its sensitivity, to the classic molecular methods of detecting the coronavirus (for example, PCR).
The professors of the University of Athens Ourania Tsitsiloni, Evangelos Terpos, Ioannis Trougakos and Thanos Dimopoulos (Rector of the University of Athens) summarize the main characteristics of this new technology.
What the study showed
Ohio University Medical Center team leader Matthew Exline, a pulmonologist and intensivist specialist, and colleagues analyzed respiratory samples from about 50 patients admitted with severe pneumonia to the Intensive Care Unit (ICU) who had to be intubated, not knowing which of them were suffering from COVID-19. They found that patients with active COVID-19 pneumonia had a different pattern of exhaled gases, which they identified with the "respiratory test" they developed.
The main exhaled gas in high concentrations was nitric oxide (NO), which, in combination with exhaled oxygen and ammonia, created in patients with severe COVID-19 a characteristic "respiratory footprint", a curve of change in their concentrations that resembles the small Greek letter omega (ω). The diagnosis of COVID-19 was made in just 15 seconds and the accuracy of the method was 88%.
Although this accuracy falls short of the already approved diagnostic tests by the FDA (which is usually close to 99%), this new "respiratory test" is fast, cheap and less invasive. In addition, a key advantage is that, unlike molecular tests that may remain positive during recovery, the "respiratory test" is only positive during COVID-19 infection.
At present the "respiratory test" has been tested on patients hospitalized in ICU, because the respiratory pattern in these patients could be monitored more intensively and more systematically. Soon, the test is expected to be tested on patients with milder COVID-19, as well as on asymptomatic individuals.
As reported by the researchers (who were trying to develop diagnostic "respiratory tests" several years before the pandemic), these new technologies give particularly encouraging clinical results, and in the future will be able to detect other diseases.
Alongside the Ohio University team, many centres around the world are working on similar technologies, although there is still no commercially available tests. For example, in the Netherlands, a rapid "respiratory test", SpiroNose, was released this year, where people who are likely to be infected with SARS-CoV-2 breathe in a special device that detects the coronavirus within 1 minute.
The positive individuals are then tested with a molecular test. At Philadelphia Children's Hospital, researchers identified in children's breath biomarkers that are unique to children with COVID-19. At Rutgers University near New York, a "respiratory test" has been developed that diagnoses COVID-19 within 10 minutes and a similar test by two startups in Singapore, gives the result within 2 minutes.
Apart from the future implementation of similar tests for the diagnosis of other diseases, for the time being perhaps the most important usefulness of "respiratory tests" for COVID-19 is the control of people in crowded gatherings and of course the control of the borders of countries.
