Chronic sinusitis pathophysiology: the role of allergy

Area of Science:

• Immunology
• Otolaryngology
• Allergy

Background:

• Chronic hyperplastic eosinophilic sinusitis (CHES) is an inflammatory sinus disease with eosinophil infiltration, often co-occurring with nasal polyps (NPs).
• Aeroallergen sensitization is common in CHES, but its direct causal role in disease development remains uncertain.
• The exact mechanisms linking allergen exposure to sinus inflammation and eosinophilia in CHES are not fully understood.

Purpose of the Study:

• To explore potential allergic mechanisms in Chronic hyperplastic eosinophilic sinusitis (CHES).
• To investigate the role of aeroallergen sensitization and alternative allergic triggers in CHES pathogenesis.
• To enhance understanding of CHES for improved therapeutic strategies.

Main Methods:

• Examined the routes of allergen entry into sinus tissues, considering impaired sinus ostia patency.
• Investigated the systemic recirculation of allergic immune cells, including eosinophils and Th2 lymphocytes.
• Considered allergic reactions to microbial peptides, such as Staphylococcus superantigens, as a potential mechanism.

Main Results:

• Allergens are unlikely to directly penetrate healthy or diseased sinus cavities.
• Inflammation and eosinophilia may develop secondary to nasal allergen exposure and systemic immune cell recruitment.
• Allergic reactions to bacterial peptides (e.g., Staphylococcus superantigens) or fungi present a plausible mechanism for CHES.

Conclusions:

• Current treatments target allergic mediators, but IgE-dependent mechanisms are not always evident.
• Omalizumab shows therapeutic promise in CHES, even in patients without clear aeroallergen sensitization.
• Further elucidation of allergy-related mechanisms in CHES is crucial for developing more effective patient treatments.