What Is The Potential Impact Of Sputum Neutrophilia On The Efficacy Of Anti-IL-5 Therapy In Patients With Severe Eosinophilic Asthma, And Are There Any Specific Biomarkers That Can Predict A Favorable Response To This Treatment In Such Patients?

The presence of sputum neutrophilia in patients with severe eosinophilic asthma may reduce the effectiveness of anti-IL-5 therapy. This is because anti-IL-5 treatments specifically target eosinophilic inflammation, leaving neutrophilic inflammation untreated. Studies suggest that higher neutrophil levels in sputum are associated with a diminished response to such therapies, indicating that neutrophils may contribute to ongoing inflammation beyond the scope of anti-IL-5 drugs.

Several biomarkers can help predict a favorable response to anti-IL-5 therapy. These include:

1. Blood Eosinophil Count: Higher levels are associated with a better response to anti-IL-5 treatments.
2. Fraction of Exhaled Nitric Oxide (FeNO): Elevated FeNO levels, indicative of eosinophilic inflammation, may predict a positive response.
3. Sputum Eosinophil/Neutrophil Ratio: A higher ratio of eosinophils to neutrophils may indicate a better response, as it suggests a more eosinophilic-driven inflammation.

In conclusion, while sputum neutrophilia may limit the efficacy of anti-IL-5 therapy, biomarkers such as blood eosinophil count, FeNO, and sputum cell ratios can help identify patients likely to benefit from this treatment.