Local nasal immunotherapy: experimental evidences and general considerations

Area of Science:

• Allergy and Immunology
• Otorhinolaryngology

Background:

• Local nasal immunotherapy (LNIT) has been explored for decades, with controlled trials emerging in the last 20 years.
• Current evidence supports the clinical efficacy of LNIT in managing allergic rhinitis.

Purpose of the Study:

• To evaluate the efficacy and safety of local nasal immunotherapy (LNIT), particularly with powdered extracts, for allergic rhinitis.
• To assess the impact of LNIT on local allergic inflammation and compare its cost-effectiveness with subcutaneous immunotherapy.

Main Methods:

• Review of available studies on LNIT for pollen- and mite-induced rhinitis.
• Analysis of clinical trials investigating aqueous and powdered extracts.
• Assessment of inflammatory markers (e.g., ICAM-1) and clinical outcomes following nasal challenges.
• Socioeconomic analysis comparing LNIT with subcutaneous immunotherapy.

Main Results:

• LNIT effectively reduces symptoms and modifies target organ responsiveness in allergic rhinitis.
• Powdered extracts demonstrate favorable clinical effectiveness with reduced local side effects compared to aqueous extracts.
• LNIT significantly reduces local allergic inflammation, including inflammatory infiltration and ICAM-1 expression.
• Preseasonal treatment appears crucial for optimal clinical efficacy, with long-lasting effects observed.
• LNIT shows a favorable cost-benefit ratio compared to classic subcutaneous immunotherapy.

Conclusions:

• Local nasal immunotherapy with powdered extracts is an effective, safe, and well-tolerated treatment for allergic rhinitis.
• The administration technique necessitates careful patient selection.
• LNIT presents a cost-effective alternative to traditional subcutaneous immunotherapy.