Histamine and its release from nasal polyps: preliminary communication.

Area of Science:

• Immunology
• Otolaryngology
• Allergy Research

Background:

• Nasal polyps are inflammatory sinonasal diseases.
• The role of allergic mechanisms in nasal polyposis requires further elucidation.

Purpose of the Study:

• To investigate the incidence of allergic disorders in patients undergoing polypectomy.
• To explore the presence of mast cell degranulation, histamine, and IgE-mediated responses within nasal polyps.

Main Methods:

• Analysis of 200 consecutive patients undergoing polypectomy.
• Transmission electron microscopy for mast cell degranulation.
• Measurement of histamine and allergen-specific IgE (RAST) in polyp fluid and serum.
• In vitro challenge of polyp tissue with allergens and anti-IgE.

Main Results:

• No increased incidence of allergic disorders observed in the patient cohort.
• Significant mast cell degranulation and high histamine levels (124-7300 ng/ml) found in polyp extracellular fluid.
• Elevated allergen-specific IgE to house-dust mite and grass pollens detected in polyp fluid in a subset of patients (4/28).
• In vitro studies indicated a potential IgE-mediated response in a small proportion of polyp tissues (4/36).

Conclusions:

• While a general increase in allergic disorders was not evident, mast cell degranulation and histamine release are significant findings in nasal polyps.
• Evidence for IgE-mediated mechanisms is present but appears limited to a subset of patients.
• Further research is warranted to fully understand the complex inflammatory pathways in nasal polyposis.