A Real Life Comparison between Allergenic Extracts and Allergenic Molecules

Area of Science:

• Immunology
• Allergology
• Biochemistry

Background:

• Serum specific IgE assays are crucial for allergy diagnosis.
• Both allergenic extracts and molecular components are currently used.
• Real-life data comparing these methods in respiratory allergy patients is valuable.

Purpose of the Study:

• To compare serum specific IgE levels against allergenic extracts versus allergenic molecules.
• To evaluate the correlation between IgE levels for Parietaria, Betulaceae, and mites using both methods.
• To assess the clinical utility and potential discrepancies of molecular diagnostics in allergy work-up.

Main Methods:

• Retrospective analysis of 489 patients with allergic rhinitis and/or asthma.
• Patients were mono-allergic to Parietaria judaica (Par j 2), Betula verrucosa (Bet v 1), or Dermatophagoides pteronyssinus (Der p 1).
• Serum IgE levels were measured using the ImmunoCap system for both crude allergen extracts and purified/recombinant allergens.

Main Results:

• Strong correlations were observed between IgE levels for birch extract and Bet v 1 (R2=0.96), D. pteronyssinus extract and Der p 1 (R2=0.71), and Parietaria extract and Par j 2 (R2=0.87).
• Significant discrepancies were found in the percentage of positive results between allergenic extracts and molecular components.
• These findings highlight both the reliability and potential limitations of molecular diagnostics.

Conclusions:

• Allergen molecular diagnostics show strong correlations with traditional extract-based IgE testing for specific allergens.
• Despite high correlations, differences in positivity rates necessitate careful interpretation of molecular diagnostics.
• Molecular diagnostics are a useful tool in allergy work-up but require cautious application in certain clinical scenarios.