Trial for developing a reference extract for future standardization of Japanese cypress pollen extracts

Area of Science:

• Allergology
• Immunology
• Pharmacology

Background:

• Japanese cedar pollinosis (JCP) is common in Japan, with many patients also allergic to Japanese cypress pollen (JCyP).
• JCyP allergy exacerbates JCP symptoms, yet no specific immunotherapy exists.
• Standardized JCyP extracts are needed for diagnostic and therapeutic advancements.

Purpose of the Study:

• To develop a reference extract for Japanese cypress pollen (JCyP).
• To standardize JCyP extracts for future diagnostic and therapeutic applications.
• To determine the average threshold dilution for positive intradermal skin tests.

Main Methods:

• Prepared a 1:20 JCyP antigen extract (Lot AA) using glycerin extraction.
• Determined protein and allergen concentrations (Cha o 1, Cha o 3).
• Assessed safety and determined average threshold dilution in 55 Japanese subjects with JCyP-specific IgE.

Main Results:

• Lot AA contained 4.7 mg/mL protein and 18.8 μg/mL Cha o 1, 1.1 μg/mL Cha o 3.
• The average threshold dilution for positive intradermal reactions was 3^6.4 (1131-fold dilution).
• No serious adverse events were observed during safety testing.

Conclusions:

• The JCyP extract (Lot AA) demonstrated in vivo allergic potency and safety.
• This extract can serve as a standardized reference antigen for JCyP pollinosis.
• It supports the development of JCyP-specific diagnostic tools and immunotherapies.