Defining the Extent of Allergenic Cross-reactivity among Mold Species

Greg A Plunkett, Michelle L Bolner


Rationale: It is important to understand the scope of cross-reactivity among mold extracts when prescribing allergen immunotherapy (AIT) formold allergic patients. Due to the large proportion of poly-sensitized patients in the clinical setting, we hypothesize that a high degree of cross-reactivity occurs between species within closely related taxonomic groups (e.g. Class, Order, and Family). Furthermore, we hypothesize that the potential for cross-reactivity exists between separate mold classes, due to protein homology. Therefore, we investigated commercial AIT extracts to better define the cross-reactivity relationships among clinically-relevant molds.

Methods: The protein content and diversity of mold extracts were established by Bradford and gel electrophoresis assays. We evaluated cross-reactivity among 15 commercial mold extracts (ALK, Inc) using mono- and poly-sensitized sera derived from both rabbits and humans. Mold proteins were separated by SDS-PAGE, immobilized on nitrocellulose membranes, and immunoblotted using the above-mentioned sera. Human sera samples were purchased from Plasma Labs and screened for mold sensitivity by Thermo Fisher ImmunoCAP. Rabbit sera specific to single molds were generated by ALK (Denmark).

Results: In agreement with our hypothesis, molds probed with sera reactive to single or dual mold species produced strong banding patterns in multiple extract lanes. Cross-reactivity was consistently observed between related species within the same Class; sera reactive to Alternaria, Aspergillus, Cladosporium or Epicoccum reacted to all extracts present from molds in the class Dothideomycetes.

Conclusions: Our results suggest an overlap in allergenic content of closely-related mold species. This finding may support the simplification of AIT formulations for treatment of mold sensitized patients.


abstract No: 


Full conference title: 

The American Academy of Allergy, Asthma & Immunology 2017
    • AAAAI 2017 (73rd)