Below is a list of the questions – and their answers – that Aerocrine’s representatives are usually asked. If your question doesn’t appear, send it in by email and we’ll get back to you soon.
Why should we measure exhaled nitric oxide NO? Isn’t spirometry good enough?
Unlike spirometry and other lung function tests, NO is a marker of inflammation. The NO value gives an indication of the ongoing inflammation status in the airways. As asthma is a disease defined as chronic inflammation, it is important and valuable to measure it. Lung function tests do not detect inflammation, only the way inflammation affects lung function, i.e., through narrowing of the airways. Until recently, inflammation could only be confirmed by an invasive biopsy. Now that can be done easily and comfortably with immediate results.
What value is there in monitoring exhaled NO values?
Regular monitoring of exhaled NO values will help doctors and patients develop a good understanding of the way the airway inflammation is progressing. A drop in the NO value indicates that the inflammation has been reduced and that the disease is under better control. A rise in the NO value indicates that the inflammation is getting worse and as such, that the disease is becoming more severe.
It is important to remember that NO testing should be used in conjunction with other clinical and laboratory evaluations to diagnose patients; it is not meant to be used on its own as a diagnostic tool.
How many publications have been written regarding exhaled nitric oxide?
Over 1500 peer-reviewed articles have been published to date on exhaled NO and nearly 600 specifically about exhaled NO and asthma. You may want to receive our Scientific Backgrounder summarizing the research in this area. To order a free copy, please send a request via email, or write to us at our office address. Likewise, you can also download a pdf version from your pc.
How can measuring exhaled NO help patient care and treatment compliance?
A cornerstone in asthma treatment is the use of anti-inflammatory therapy, such as inhaled corticosteroids (ICS). Exhaled NO values can be used to monitor the effects of treatment.
For patient not on corticosteroids:
• High NO levels signal the need to treat the underlying inflammation with appropriate ICS dosage.
• Low NO levels suggest no atopic asthma and that another diagnosis should be considered.
For patients already on corticosteroids:
• A rise in NO value may indicate that the patient is not completely following the prescribed anti-inflammatory treatment or that the disease is worsening.
• Conversely, a decrease in NO can confirm effective ICS dosage
Diagnosis based on NO testing should be done in conjunction with other clinical and laboratory evaluations. NO testing it is not meant to be used on its own as a diagnostic tool.
Why do some patients have high exhaled levels of NO?
Exhaled NO is a marker of airway inflammation. It is produced in the epithelial cells of the bronchi as part of the IgE-mediated inflammatory process triggered by allergens. In other words, patients have high levels of exhaled NO if they have an ongoing, active eosinophilic inflammation in the airways.
Published research provides strong evidence that exhaled NO reflects airway inflammation.[Van den Toorn 2001] [Payne 2001]