WHO/IUIS Allergen Nomenclature: Providing a common language

Abstract

A systematic nomenclature for allergens originated in the early 1980s, when few protein allergens had been described. A group of scientists led by Dr. David G. Marsh developed a nomenclature based on the Linnaean taxonomy, and further established the World Health Organization/International Union of Immunological Societies (WHO/IUIS) Allergen Nomenclature Sub-Committee in 1986. Its stated aim was to standardize the names given to the antigens (allergens) that caused IgE-mediated allergies in humans. The Sub-Committee first published a revised list of allergen names in 1986, which continued to grow with rare publications until 1994. Between 1994 and 2007 the database was a text table online, then converted to a more readily updated website. The allergen list became the Allergen Nomenclature database (www.allergen.org), which currently includes approximately 880 proteins from a wide variety of sources. The Sub-Committee includes experts on clinical and molecular allergology. They review submissions of allergen candidates, using evidence-based criteria developed by the Sub-Committee. The review process assesses the biochemical analysis and the proof of allergenicity submitted, and aims to assign allergen names prior to publication. The Sub-Committee maintains and revises the database, and addresses continuous challenges as new "omics" technologies provide increasing data about potential new allergens. Most journals publishing information on new allergens require an official allergen name, which involves submission of confidential data to the WHO/IUIS Allergen Nomenclature Sub-Committee, sufficient to demonstrate binding of IgE from allergic subjects to the purified protein.

Keywords: Allergen database; IgE; Isoallergen; Taxonomic name; WHO/IUIS Allergen Nomenclature.

Fig. 1

Historical perspective: A) Key discoveries in the allergy field. B) Developments in allergen nomenclature. Important milestones in development of clinical allergy and in nomenclature are described.

Fig. 2. Summary of workflow for the submission and evaluation of candidate allergens to the WHO/IUIS Allergen Nomenclature Sub-Committee

In many cases questions are forwarded to submitters in order to assure an appropriate science-based review. The goal is to provide a decision within two weeks, but sometimes decisions are delayed. Submitters should contact the Chair if they have questions.

Fig. 3. Essential criteria for allergen acceptance

The primary questions of the submission form are designed to allow the reviewers to understand what was done, how complete the characterization of the allergen candidate was, indicating the protein sequence and physical characteristics, the selection of serum donors, tests for IgE binding as well as biological tests (SPT or BAT). The scientists submitting the form should provide enough information to demonstrate that their protein is most likely to be an allergen.

Fig. 4. Genetic and chemical structure of group 1 Blattela germanica allergens

A) Bla g 1 isoallergens are encoded by different genes (in italics), which are composed of fully and partially repeated genetic elements indicated by the boxes. Blue rectangles represent regions with 76–99% sequence identity to either the yellow or green rectangle. The defined allergens at WHO/IUIS only partially cover the full open reading frame. B) The structure of the second half of Bla g 1.0101 was determined (4JRB, Mueller et al., 2013). The yellow and green coloring corresponds to the portion of gene similarly colored in A. The long linkers between structured elements suggest the full protein will resemble beads on a string. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)