Table 2.

Comparison of immunological markers eosinophilic airway diseases.

Feature/Disease	CRSwNP	Eosinophilic Asthma	EGPA	ABPA
Definition	Inflammatory ailment in nasal mucosa and sinuses	Asthma subtype with high eosinophil levels	Multisystem inflammatory disease affecting respiratory tract and small to medium blood vessels	Hypersensitive response to Aspergillus fungus
Prevalence	5-15% in general population	Approx. half of asthma cases	1.22 cases per million person-years	0.7-3.5% in adults with asthma, 6-8- 12% in cystic fibrosis
Predominant Type of Inflammation	Type 2 inflammation	Type 2 inflammation	Eosinophil-rich granulomatosis	Allergic reaction
Key Cells Involved	Eosinophils, T cells Th2 (Th17/ Treg imbalance)	Eosinophils, Th2 cells, ILC2s	Eosinophils, T cells (Th1, Th2, Th17)	Eosinophils, Th2 cells
Epithelial Barrier Dysfunction	Yes	–	–	–
Role of Eosinophils	Central in inflammation	Indicator of disease severity	Predominant in inflammation	Effector cells in lung damage
Cytokines and Chemokines	IL-4, IL-5, IL-13, IL- 17, IFN-γ	IL-4, IL-5, IL-13, eotaxins	IL-4, IL-5, IL-13, eotaxin-3	IL-4, IL-5, IL-13
Predominant Immune Response	Type 2, Th2 predominance	Type 2, Th2 predominance	Th2-driven, Th1 and Th17 involvement	Th2 response predominance
IgE Levels	–	Elevated in severe cases	Elevated, associated with ANCA	Significantly elevated
Associated Conditions	Asthma, especially type 2	–	Asthma, sinusitis, allergic rhinitis, purpura, neuropathy	Asthma/ cystic fibrosis
Treatment Targets	Type 2 inflammation, epithelial function	Type 2 inflammation, eosinophil levels	Th2 cytokines, eosinophil activation	Th2 immune response, fungal colonization

CRSwNP, chronic rhinosinusitis with nasal polyps; eBA, eosinophilic bronchial asthma; EGPA, Eosinophilic Granulomatosis with Polyangiitis; and ABPA, allergic bronchopulmonary aspergillosis; IL, interleukin; IFN-γ, interferon-gamma; ILC-2, innate lymphocyte-2; and Th, T lymphocyte helper.