Maximising the benefit of FeNO testing for airway inflammation in the daily clinic

We caught up with Professor Vibeke Backer; who is a Professor in both pulmonology and global airways. In her webinar, Professor Backer talks us through various clinical studies involving FeNO and the significance of these in maximising the benefit of FeNO testing for airway inflammation in daily clinic. She gave us an exclusive Q&A about how she uses FeNO in her daily clinic, read on to find out more...

Professor Vibeke Backer joined us for an exclusive NIOX® webinar, taking us through studies about FeNO, and how to maximise the benefit of FeNO in daily clinic. In the webinar she discusses the relationship between FeNO and sputum eosinophils in asthma diagnostics, clinical examples of FeNO for diagnosing and managing asthma, and much more. You can watch the webinar to see her talk about these studies here.

How do you manage your asthma patients and what is your process?

Professor Backer explains her approach in both her hospital global airways clinic and outside hospital asthma clinic. “I go for treatable traits, which means that the first thing I will measure in both the patient at the hospital and outside hospital is FeNO. I do that because I think it is an important measurement but also because it should be the first one to be measured before lung function.”¹

Professor Backer explains that following the FeNO test, she will then measure lung function, a mannitol provocation test, and performs an allergy test.¹

“So, when I have the patient in the asthma clinic, I will have the value of FeNO, I will have the level of lung function, the hyperresponsiveness and the possible allergy.” ¹

The process is slightly different in the hospital, as Professor Backer explains she will usually do FeNO, spirometry and an Asthma Control Questionnaire. Following this she will also do a Sino-Nasal Outcome Test (SNOT)-22 which checks for chronic rhinosinusitis.¹

Can you explain a time where you experienced a patient having non-Type 2 or neutrophilic asthma and FeNO testing helped to identify this?

“When I have the patients in the outpatient clinic and they have the FeNO measured and if they have like a value about 50 [parts per billion (ppb)], I am pretty sure that they have asthma and they must have a positive mannitol provocation test because they are you know, associated with each other.” Professor Backer states.¹

She explains that a low FeNO score, for example less than 20 ppb, doesn’t mean that a patient doesn’t have asthma, it may be non-Type 2 asthma.¹ “But what you should be aware of is that the variation due to treatment is in the higher end, like you need to change like eight or 10 parts per billion in FeNO, then you have better asthma control. It is actually the same in the lower end. So, if you have 19 for example, or 15, you probably with the control will have like eight, for example.”¹ She explains that this means that the asthma is well-controlled with good adherence for non-Type 2 asthma. She prescribes non-Type 2 asthmatics less inhaled steroids and more beta-2 agonists, like long-acting beta-2 agonists (LABA).¹

If a patient presents with moderate FeNO, for example 35 ppb, how would you deal with this?

“If I have a patient with like 35 parts per billion in FeNO, I will expect a Type 2 disease. I will expect even though it might have a negative asthma test because only 88% of the asthma test will be positive if you have a FeNO about 33, which is the same as 35.”¹ Professor Backer says that at this point she looks more into the problem by doing other asthma tests such as peak flow variation, reversibility testing and methacholine to reach a diagnosis.¹

How do you deal with patients who have a diagnosis of asthma but are smokers? Do you consider reducing their baseline FeNO or do you create personalised values for them?

“In Denmark we have a high frequency of tobacco consumption,” Professor Backer explains.¹ “I would from the first point discuss tobacco consumption and ask them to stop smoking.”¹

“It is not healthy for their lungs and it is especially not healthy when they are asthmatic.”

She describes what smoking does to FeNO and how she gets around this. FeNO is lower in current smokers, and she explains that she uses low FeNO as a measure like in non-Type 2 asthma patients, “but I cannot really know whether it is a non-Type 2 asthma patient.”¹ The measurements and wellbeing of the patient is looked at more in these cases, instead of the changes in FeNO.¹

Thank you to Professor Backer for her insights into FeNO in the clinic. If you would like to view the whole webinar on Maximising the benefit of FeNO testing for airway inflammation in the daily clinic, you will find it in our webinar section here.