A study on antigenic and allergenic changes during storage in three different biological extracts

Area of Science:

• Allergen research
• Immunology
• Tropical medicine

Background:

• Allergens from tropical regions like Prosopis juliflora (pollen), Rhizopus nigricans (fungi), and wheat dust (dust) are significant health concerns.
• Understanding allergen stability is crucial for effective diagnosis and treatment.

Purpose of the Study:

• To evaluate the stability of three common tropical allergens under various storage conditions.
• To determine the impact of storage temperature, duration, and preservatives on allergen integrity and activity.

Main Methods:

• Allergen extracts (Prosopis juliflora, Rhizopus nigricans, wheat dust) were stored in buffers with phenol or glycerol.
• Storage conditions included temperatures from 4-55°C for 15-60 days.
• Stability was assessed using protein content analysis, isoelectric focusing, rocket immunoelectrophoresis, and radioallergosorbent test (RAST) inhibition.

Main Results:

• Prosopis juliflora extract showed significant protein degradation at 40°C within 45 days, with some antigenic proteins degrading even at 25°C within 15 days.
• Glycerol (50%) enhanced the stability of Prosopis juliflora and Rhizopus nigricans extracts, retaining over 50% activity at 55°C for 40 days.
• Wheat dust extract stability was not significantly affected by glycerol, and all extracts lost significant allergenic activity at higher temperatures (25-55°C) within 15 days.

Conclusions:

• Allergenic extracts exhibit differential stability based on their source and storage conditions.
• Glycerol is a potentially effective stabilizer for certain pollen and fungal allergen extracts.
• Individual stability testing for each allergen extract is essential for reliable diagnostic and therapeutic applications.