Allergen Microarray Indicates Pooideae Sensitization in Brazilian Grass Pollen Allergic Patients

Area of Science:

• Allergy and Immunology
• Molecular Allergology
• Clinical Medicine

Background:

• Grass pollen, especially Lolium multiflorum, is a significant allergen in Southern Brazil.
• The specific IgE sensitization profile of Brazilian patients to individual grass pollen allergens was previously unknown.

Purpose of the Study:

• To determine the IgE sensitization profile of Brazilian grass pollen allergic individuals to specific allergen molecules.
• To investigate cross-reactivities among different grass pollen allergens.

Main Methods:

• Sera from 78 grass pollen allergic patients were analyzed using chip technology with 103 purified allergens.
• IgE-ELISA inhibition experiments were conducted using Lolium multiflorum, Phleum pratense extracts, and a recombinant fusion protein.

Main Results:

• Phleum pratense allergens Phl p 1 (95%), Phl p 5 (82%), and Phl p 2 (76%) were the most frequently recognized.
• A high degree of IgE cross-reactivity was observed between Phleum pratense, Lolium multiflorum, and a recombinant timothy grass fusion protein.
• Most patients were exclusively sensitized to grass pollen allergens.

Conclusions:

• Component-resolved analysis indicates a sensitization profile consistent with Pooideae grass pollen allergy in Brazilian patients.
• The significant cross-reactivity suggests Phleum pratense allergens are suitable for diagnosing and developing immunotherapy for this population.