Use of modified radioallergosorbent testing in determining initial immunotherapy doses

Area of Science:

• Allergy and Immunology
• Diagnostic Testing

Background:

• The modified radioallergosorbent test (RAST) is proposed as an alternative to skin testing for allergy diagnosis.
• Proponents suggest modified RAST allows for safer initiation of immunotherapy at higher concentrations and fewer injections.

Purpose of the Study:

• To evaluate the claimed advantages of modified RAST over skin testing in allergy diagnosis and immunotherapy.
• To compare immunotherapy dosing and injection schedules based on modified RAST results versus conventional methods.

Main Methods:

• Determined the most important allergen for 58 patients with seasonal allergic rhinitis via history, skin testing, and aeroallergen surveys.
• Performed modified RAST for identified allergens.
• Compared projected immunotherapy schedules (initial concentration, total injections) based on modified RAST classes (3, 4, 5) with conventional schedules.

Main Results:

• 67% of patients were modified RAST class 5, 31% were class 4, and 1% were class 3.
• Projected immunotherapy schedules for modified RAST class 5 (1:62,500 w/v, 27 injections) and class 4 (1:12,500 w/v, 21 injections) showed minimal differences compared to the conventional schedule (1:100,000 w/v, 23 injections).

Conclusions:

• The modified RAST does not provide a significant advantage over skin testing for determining allergy immunotherapy protocols in this patient population.
• Conventional immunotherapy dosing and schedules appear comparable to those derived from modified RAST results.