Eosinophilic Asthma and Nasal Polyps: The Shared Biomarker Science

Eosinophilic asthma and nasal polyps often go hand in hand, sharing underlying biology that helps explain why many people experience both conditions. Understanding the eosinophilic asthma and nasal polyps biomarker link can guide better diagnosis and targeted treatments, improving quality of life for millions worldwide. This article breaks down the science in clear terms, highlights key biomarkers, and suggests practical next steps.

What Are Eosinophilic Asthma and Nasal Polyps?

Eosinophilic asthma and nasal polyps are both driven by an overactive type 2 (T2) inflammatory response, in which eosinophils—a type of white blood cell—play a central role.

• Eosinophilic Asthma:
  • A subtype of asthma marked by elevated eosinophils in the airways and blood.
  • Symptoms include wheezing, shortness of breath, cough, and chest tightness.
  • Often more severe, with frequent exacerbations and poor response to standard inhalers alone.

• Nasal Polyps:
  • Soft, benign growths on the lining of the nasal passages or sinuses.
  • Can cause nasal congestion, loss of smell, facial pain, and chronic sinus infections.
  • Regularly linked to asthma—up to 40% of people with severe asthma have nasal polyps (1).

The Eosinophilic Asthma and Nasal Polyps Biomarker Link

Biomarkers are measurable indicators of a biological state or condition. In eosinophilic asthma and nasal polyps, several biomarkers overlap, reflecting the shared T2-driven inflammation:

1. Blood Eosinophil Count

   • A simple blood test measuring circulating eosinophils.
   • Counts ≥150–300 cells/µL often signal T2 inflammation.
   • Higher counts correlate with more severe asthma and larger polyps (2).

2. Fractional Exhaled Nitric Oxide (FeNO)

   • Measures nitric oxide in exhaled breath, a marker of airway inflammation.
   • Levels ≥25 parts per billion (ppb) suggest eosinophilic airway disease.
   • Elevated FeNO often accompanies nasal polyp growth.

3. Serum Total IgE

   • Reflects overall allergic (atopic) sensitization.
   • Many patients with nasal polyps and eosinophilic asthma have high IgE, even without clear allergies (3).

4. Periostin

   • A protein produced in response to T2 cytokines (IL-4, IL-13).
   • Higher levels in blood or nasal tissue samples link to both polyp burden and airway eosinophilia.

5. Local Tissue Cytokines (IL-5, IL-13)

   • Detected in nasal tissue or sputum.
   • IL-5 drives eosinophil growth and survival, fueling both airway and sinus inflammation.

Why the Shared Biomarker Science Matters

Understanding the eosinophilic asthma and nasal polyps biomarker link changes how clinicians approach diagnosis and treatment:

• Early identification of T2 inflammation can prevent repeated exacerbations and sinus surgeries.
• Biomarker-guided therapy allows personalized treatment plans rather than a one-size-fits-all approach.
• Targeted biologic medicines now exist to block specific pathways (e.g., anti-IL-5, anti-IL-4/13, anti-IgE), directly addressing the underlying cause.

Clinical Implications

• Diagnosis
– Blood and breath tests are easy to perform in outpatient settings.
– Nasal endoscopy or CT scans confirm the presence and size of polyps.

• Treatment
– Inhaled corticosteroids and ICS/LABA combinations remain first-line for asthma.
– Nasal corticosteroid sprays can shrink or soften polyps.
– Biologics (e.g., mepolizumab, dupilumab) are approved for both severe eosinophilic asthma and chronic rhinosinusitis with nasal polyps, based on biomarker thresholds.

• Monitoring
– Regular biomarker checks help gauge treatment response.
– Adjustments can be made to biologic dosing or other medications as needed.

Recognizing When to Seek Help

If you're experiencing persistent wheezing, difficulty breathing, or chronic nasal congestion with reduced smell—especially if you've been diagnosed with asthma or nasal polyps in the past—it may be time to explore the eosinophilic asthma and nasal polyps biomarker link more closely.

• Take a few minutes to use Ubie's free AI-powered Bronchial Asthma symptom checker to get personalized insights about your respiratory symptoms and understand whether you should see a specialist.
• Keep track of your symptoms, medication use, and any triggers you notice (e.g., allergens, infections).

Next Steps: Working with Your Healthcare Team

1. Discuss Biomarker Testing
   • Ask your doctor about blood eosinophil counts, FeNO measurement, and serum IgE.
   • If you have nasal symptoms, inquire about evaluation by an ENT specialist for polyps.

2. Review Your Treatment Plan
   • Ensure you're on optimal asthma medications and nasal sprays.
   • Bio­logics may be appropriate if standard therapies aren't controlling your symptoms.

3. Lifestyle and Support
   • Avoid known triggers like tobacco smoke and strong chemical odors.
   • Maintain good indoor air quality and consider allergy-proofing measures.
   • Stay up to date with vaccinations, including influenza and COVID-19, to reduce exacerbation risk.

Summary

The eosinophilic asthma and nasal polyps biomarker link highlights a shared type 2 inflammatory pathway. By measuring biomarkers such as blood eosinophil count, FeNO, IgE, and periostin, clinicians can diagnose, treat, and monitor these interconnected conditions more effectively. Incorporating biologic therapies tailored to your biomarker profile has revolutionized care for many patients with severe asthma and nasal polyps.

If you suspect you may have eosinophilic asthma, nasal polyps, or both—especially if you struggle with uncontrolled symptoms—start by checking your symptoms with Ubie's free Bronchial Asthma assessment tool to better understand your condition before your next doctor's visit. Always speak to a doctor about any serious or life-threatening symptoms. Your healthcare team can help develop a personalized plan to manage inflammation, reduce symptoms, and improve your overall quality of life.