[Diagnostic value of RAST-classes in various allergens]

Area of Science:

• Allergen-specific IgE testing
• Immunology
• Diagnostic value of RAST classes

Context:

• Radio-Allergo-Sorbent-Test (RAST) quantifies specific IgE in serum.
• RAST results are categorized into four classes (1-4), indicating IgE levels.
• The diagnostic utility of RAST classes varies across different allergen groups.

Purpose:

• To evaluate the diagnostic significance of different RAST classes for various allergens.
• To determine if lower RAST classes hold clinical value in specific allergic conditions.
• To compare RAST class distribution between different allergen types.

Summary:

• A study of 700 patients and 13,600 allergens using RAST found 2441 positive reactions.
• Weeds, house dust, and mold allergies predominantly show lower RAST classes (1-2) in over 90% of cases.
• Grass pollen allergy shows a significant percentage of positive tests in RAST class 3, with total IgE increasing pathologically up to RAST class 4.

Impact:

• RAST class 1 demonstrates diagnostic value for house dust, mold, and weed pollen allergies, supporting therapeutic interventions.
• Lower RAST classes in mold, house dust, and weed allergies correlate with already pathological total IgE levels.
• Elevated total IgE levels in grass pollen allergy extend to RAST class 4, suggesting different diagnostic thresholds.