Eosinophilic Asthma and How it Differs from Allergic Asthma
Eosinophilic asthma and allergic asthma are two subtypes of asthma, Eosinophilic asthma is characterized by high levels of eosinophils (a type of white blood cell) in our airways. It is more common in adults and is more severe as compared to allergic asthma. 1
Globally, about 31% of individuals with asthma have the eosinophilic type. In moderate-to-severe asthma cases, this percentage can rise up to approximately 50%. 2, 3
Eosinophilic and allergic asthma share some similarities but have distinct underlying mechanisms, triggers, and treatment approaches. Let’s understand the key differences:3
Allergic Asthma :3
- Triggered by exposure to allergens (e.g., pollen, dust mites, pet dander, mold).
- Biomarkers: Elevated levels of IgE are seen in Allergic Asthma, as it involves an IgE
mediated hypersensitivity response (Type I immune reaction).
- Usually begins in childhood and is associated with other allergic conditions (allergic rhinitis, eczema and so on).
- Symptoms include coughing, wheezing, shortness of breath, and chest tightness upon allergen exposure.
- Allergic asthma usually responds well to anti-IgE medications.
Eosinophilic Asthma: 1, 2, 3
- A subtype of asthma driven by eosinophilic inflammation
- Biomarkers show elevated levels of Eosinophils in blood/sputum.
- May or may not be of allergic nature (some cases are non-allergic).
- Often much more severe as well as persistent.
- Diagnosed more in adults (although it can occur in children).
- Has been linked to chronic sinusitis, nasal polyps, and aspirin-exacerbated respiratory disease (AERD). 1
- Just anti-IgE medicines are not enough to manage eosinophilic Asthma, as it usually requires anti-IL-5/IL-4/IL-13 biologics. 1, 2
Overlap of the two types: 3
- Some patients have both allergic and eosinophilic asthma as Allergic asthma can sometimes lead to eosinophilic inflammation over time. Such scenarios are likely to be more severe in nature and less responsive to standard ICS(inhaled corticosteroids) therapy.
The dark side of steroid-dependence: 4, 5,9
Patients with severe eosinophilic asthma often require long-term oral corticosteroids (OCS) to control symptoms and prevent exacerbations.
However, being on steroids long-term leads to multiple systemic side effects, making steroid-sparing therapies (like anti-IL-5/IL-4/IL-13 biologics) a valuable treatment option.
Let’s understand some side effects of steroidal medicines.
Common Side Effects of Chronic Steroid Use: 4
- Diabetes: Patients receiving steroidal medicines may suffer from steroid-induced insulin resistance.
- Adrenal suppression: Long-term Corticosteroid use supresses normal adrenal gland function and hence comes with an increased risk of adrenal crisis especially upon sudden withdrawal.
- Dyslipidemia: Increased levels of LDL, triglycerides.
- Weight Gain: Steroidal medicines are commonly associated with weight gain, central obesity, moon face & “Cushingoid” appearance.
- Osteoporosis: Steroidal medicines are linked to increased fracture risk due to reduced bone formation.
- Immunosuppression: Increased susceptibility to bacterial, fungal, and viral infections due to a lowered immune response caused by steroidal medicines. They can also cause reactivation of latent TB or herpes viruses
- Poor wound healing is also a common side effect of being on steroids long-term.
Gradually decreasing Steroid dependence and Overcoming its Side-Effects :
Some side-effects of steroids can be managed with lifestyle changes but if steroid therapy is contraindicated in someone or if its not good enough, there are quite a few things a physician may consider to manage asthma as well as decrease steroid dependence. Here are a few strategies to decrease steroid intake manage steroid side effects:
Bone Protection 8
- As osteoporosis is a major side-effect of steroids, supplementation with Calcium and Vitamin D3+K2 supplementation for optimal bone health is indicated in most patients. Bisphosphonates are also beneficial in patients who are at a high risk for bone fractures.
- DEXA scans every few years/ as directed by the physician for monitoring bone health.8
Metabolic Monitoring 9
- Diabetes screening and Lipid profile tests to monitor blood sugar and dyslipidemia which are associated with steroid therapy.
Infection Prevention
- Since steroid therapy is associated with immunosuppression, it is essential to do a TB screening (especially before biologics therapy) and all advised immunizations.
Gradual Steroid Tapering
- Slow reduction of steroid dosage under physician’s supervision is advised to avoid adrenal insufficiency. Patients are regularly monitored for their asthma & adrenal function. 6
Biologic Therapies (Steroid-Sparing Agents) 10
- Anti-IL-5/IL-5Rα medicines such as Fasenra which reduce exacerbations and steroid dependence. An Anti-IgE medicine if allergic component present in the asthmatic condition.
How Fasenra (Benralizumab) Helps Combat Steroid Dependence in Eosinophilic Asthma: 11
Fasenra (benralizumab) is a monoclonal antibody approved as an add-on maintenance treatment for severe eosinophilic asthma. It is a steroid-sparing biologic that significantly reduces the need for oral corticosteroids (OCS) 1, 2
Let’s understand how: 2, 11
1. Fasenra’s Mechanism of Action: Targeted Eosinophil Depletion
- Fasenra binds to the IL-5 receptor alpha (IL-5Rα) on eosinophils, triggering apoptosis (cell death) via a NK cell-mediated processes.
- Unlike most biologics which block IL-5, Fasenra actually directly kills eosinophils, leading to a rapid and a much more sustained reduction in airway inflammation caused by eosinophils.
2. Reduction in Exacerbations & Inflammation
- By eliminating eosinophils, Fasenra decreases the frequency and severity of asthma
exacerbations, hence reducing the need for rescue steroids.
3. Allows for Safe and Gradual Tapering of Steroid doses 13
- Clinical trials studying Fasenra’s efficacy show a 50–75% reduction in OCS use while maintaining asthma control. This allows for safely reducing dependence on steroids.
Safety Considerations for steroid tapering and Fasenra therapy: 12
- Fasenra is not an emergency rescue therapy or even a monotherapy- it is usually used alongside other medicines. Patients may still need SABA/ICS for flare-ups.
- Monitoring for adrenal insufficiency during OCS tapering is crucial, steroid tapering has been linked with adrenal crisis,
- Check eosinophil levels regularly as Fasenra can cause near-complete depletion of eosinophils.
- Helminth infections: Check for parasitic infections in at-risk populations before starting Fasenra.
Fasenra Side Effects : 12
While Fasenra is generally well-tolerated, potential adverse effects include:
- Injection-site reactions (redness and discomfort).
- Hypersensitivity reactions.
- Headache, fever and pharyngitis.
Is Fasenra a good choice for you? 2, 11
Fasenra is ideally indicated in patients who:
- Have frequent exacerbations despite maximal inhaler therapy.
- High eosinophil levels (blood/sputum).
- Oral corticosteroid (OCS)-dependent patients.
- Patients who cannot tolerate a higher steroid dose.
In conclusion, Fasenra is a targeted therapy that can improve countless lives. Eosinophilic Asthma is a debilitating disease- apart from the breathlessness, it also comes with endless side-effects of steroid therapy which make it much harder to live with. Fasenra addresses this disease at its root by eliminating the very eosinophils that worsen asthma and lung health.
Including Fasenra in the Treatment Plan for overcoming severe Asthma not only frees patients from their steroid dependence to a significant extent but also reduces the exacerbation episodes, greatly empowering patients and physicians both.13
Accessing Fasenra in India:
Rx4u is a platform dedicated to bringing life-saving medication from across the world to your doorstep. Rx4u’s global supply network ensures that patients in India benefit from rarely available life-saving medicines through their Named Patient Purchase programme. Availability of medicines such as Fasenra is a step forward in optimal health-care for patients in India. With trusted platforms like Rx4u, patients now have a better chance at an easier life.
Note:
The information provided is for education purpose only and is subjected to prescribing information of the drug and the guidance of your treating physician. Always consult your health care provider before making any medical decision for starting your treatment.
References:
1.https://pmc.ncbi.nlm.nih.gov/articles/PMC10931088/#:~:text=Asthma%20is%20a%20prevalent%20chronic,slow%20the%20progression%20of%20asthma.
2.https://www.fasenra.com/home/eosinophilic-asthma
3.https://pmc.ncbi.nlm.nih.gov/articles/PMC8048421/#:~:text=In%20this%20post%20hoc%20analysis,management%20and%20guide%20treatment%20options.
6.https://publications.ersnet.org/content/erjor/5/3/00009-2019#:~:text=The%20OCS%20tapering%20phase%20will,the%20average%20of%202%20days.
8.https://pmc.ncbi.nlm.nih.gov/articles/PMC8259736/figure/f0003/
9.https://pmc.ncbi.nlm.nih.gov/articles/PMC8259736/#:~:text=General%20Measures,in%20regular%20weight%2Dbearing%20exercises.&text=Glucocorticoid%2Dinduced%20hyperglycemia%2C%20when%20present,and%20decreased%20bone%20matrix%20competence.
10. https://pubmed.ncbi.nlm.nih.gov/30461530
11.https://www.nejm.org/doi/full/10.1056/NEJMoa1703501
12.12. https://www.healthline.com/health/drugs/fasenra-side-effects#precautions
