Inflammatory Biomarkers in Allergic Respiratory Diseases

Allergic respiratory diseases, including asthma and allergic rhinitis, are driven by complex immune responses characterised by airway inflammation and tissue remodelling. Key biomarkers encompass cellular mediators such as eosinophils and neutrophils, soluble proteins including periostin and cytokines (IL-4, IL-5, IL-13), and non-invasive metrics like fractional exhaled nitric oxide. These markers aid in differentiating endotypes, predicting exacerbations and guiding personalised therapies. Recent advances have expanded the repertoire of systemic indicators—white blood-cell ratios, erythrocyte dynamics and Notch signalling components—that reflect both acute hypersensitivity and chronic allergic inflammation. Integration of these biomarkers into clinical pathways promises earlier risk stratification, more precise monitoring of treatment efficacy (including allergen-specific immunotherapy) and improved outcomes across diverse patient populations.

Research from Nature Portfolio

Emerging work has redefined the role of neutrophils in allergic rhinitis by identifying functionally distinct subsets. Activated neutrophils expressing high CD16 and low CD62L accumulate in nasal mucosa during pollen season, exhibit T-cell priming capacity and promote eosinophil migration, suggesting a cooperative network between innate and adaptive arms. In parallel, controlled allergen challenges reveal a rapid systemic shift in circulating blood cells: erythrocyte counts fall sharply while segmented neutrophils rise, regardless of prior sublingual immunotherapy. This mobilisation underscores the dynamic interplay between hypoxia compensation and acute hypersensitivity, positioning erythrocyte and neutrophil kinetics as potential early indicators of allergen-driven airway responses.

Inflammatory Biomarkers in Allergic Respiratory Diseases publication trend

The graph below shows the total number of articles in inflammatory biomarkers in allergic respiratory diseases across all publications each year (not limited to Nature Index journals).

Technical terms

Biomarker: a measurable indicator of physiological or pathological processes.

Eosinophil: a granulocytic white blood cell central to Th2-mediated allergic inflammation.

Neutrophil: a granulocytic white blood cell pivotal in acute inflammatory responses.

Neutrophil-to-lymphocyte ratio: the proportion of neutrophils to lymphocytes, used as an index of systemic inflammation.

Immunoglobulin E (IgE): an antibody class that binds allergens and triggers mast cell degranulation.

Allergen-specific immunotherapy: a treatment exposing patients to gradually increasing allergen doses to induce immune tolerance.

Notch signalling: a conserved cell–cell communication pathway regulating T cell differentiation and immune homeostasis.

References

1. Distinguishing Childhood Asthma Exacerbations from Stable Asthma: The Utility of Inflammatory White Blood Cell Biomarkers. Diagnostics (2024).
2. Elevated Neutrophil-to-Lymphocyte Ratio Is Associated with Severe Asthma Exacerbation in Children. Journal of Clinical Medicine (2023).
3. A possible role for neutrophils in allergic rhinitis revealed after cellular subclassification. Scientific Reports (2017).
4. Peripheral Erythrocytes Decrease upon Specific Respiratory Challenge with Grass Pollen Allergen in Sensitized Mice and in Human Subjects. PLOS ONE (2014).
5. Sublingual house dust mite immunotherapy has no impact on decrease of circulating erythrocytes upon airway allergen challenge in allergic rhinitis. Scientific Reports (2017).
6. Upregulated expression of Notch1/4 - JAG-1/DLL-1 detected in allergic rhinitis. Allergy, Asthma & Clinical Immunology (2023).