What do diseases like asthma, atopic dermatitis, or a food allergy have in common? In addition to their high prevalence, they all belong to the group of type 2 inflammatory diseases, pathologies whose specific response of the immune system can contribute to having unpredictable, persistent or uncontrollable symptoms , reducing the patient’s quality of life, both physically and mentally.
On the occasion of the event ‘The connection of type 2 inflammation: discovering hidden connections ‘, which Sanofi Genzyme and Regeneron organized last October within the framework of the congress of the European Respiratory Society , we have interviewed Ian Pavord, professor at the University from Oxford and a leading expert in respiratory medicine.
What is a type 2 inflammatory disease?
Type 2 inflammation is a normal response of the immune system. But, when it becomes hyperactive, it can play a key role in inflammatory diseases such as atopic dermatitis, asthma, nasal polyps, eosinophilic esophagitis, certain food and environmental allergies, or respiratory disease exacerbated by aspirin. In addition, people with a type 2 inflammatory disease are at greater risk of living with another disease of the same type.
Is it known why this immune system response occurs? Are there any genetic factors involved?
Genetic factors can predispose people to excess type 2 inflammation, and other environmental triggers such as tissue damage can also play a role. Also, type 2 inflammation manifests itself in different ways depending on the person affected.
Recent scientific studies have shown that excess type 2 inflammation underlies different atopic, allergic and inflammatory conditions. As the symptoms of these diseases are unpredictable and random, many are likely to go undiagnosed. How many people is estimated to be able to suffer from one or more of these ailments without being diagnosed?
Lack of awareness of these conditions means that people cannot fully understand their illness or diseases, how they are connected, and what treatment options are available to them.
It is difficult to know this information exactly because, as I was saying, many people live with various type 2 inflammatory diseases . For example, up to 35% of people with severe asthma also have atopic dermatitis. About 50% of patients with chronic rhinosinusitis with nasal polyps (CRS) also have asthma and up to 43% of those with severe asthma also have CRS. Likewise, 17% of people with CRS suffer from atopic dermatitis and 13% of people with moderate to severe atopic dermatitis suffer from CRS.
75% of patients with moderate to severe atopic dermatitis have not controlled the disease and 45% of patients with asthma in Europe who are under treatment are not controlled either. On the other hand, around 79% of patients with CRS experience recurrent polyps one year after surgery.
What are the biggest challenges when it comes to studying these diseases? What lines of research are open and which are the most promising?
The biggest challenge is getting patients and doctors to understand that evaluation for type 2 inflammation is a key component in the diagnosis of certain diseases, such as asthma. In the case of this condition, for example, elevated biomarkers of type 2 inflammation are associated with the risk of asthma attacks and with the likelihood that inhaled corticosteroids and other treatments will be successful.
There is recent work that shows very consistently that patients with elevated blood eosinophil counts and exhaled nitric oxide are at high risk for asthma attacks, regardless of the traditional measures we use to assess asthma control. It is now clear that control of type 2 inflammation in the airways is an important additional goal of asthma therapies.
