Development of a PCR-based tool for detecting immunologically relevant Alt a 1 and Alt a 1 homologue coding sequences

Alt a 1 has been recognized as the most important allergen produced by the Pleosporaceae family and is a risk factor for asthma development and/or exacerbation. The aim of this study was to develop a detection tool that is highly specific for species that produced airborne Alt a 1. Based on the highly conserved internal nucleotide region of the several Alt a 1 sequences that are available in GenBank, a pair of primers (Alta1CF/Alta1CR) was designed. A set of primers used by other authors for the production of recombinant Alt a 1 (A21F/A21R) was also tested. The molecular analyses were based on the polymerase chain reaction (PCR) amplification and sequencing of the cDNA that was obtained from thirteen common fungal species. The PCR system that utilized Alta1CF/Alta1CR was highly specific, sensitive, and was able to detect an amplicon of approximately 180 bp from Alt a 1 and Alt a 1-like encoding genes from A. alternata, A. tenuissima, A. infectoria, U. botrytis, and S. botryosum. In contrast, the A21F/A21R primers were specific for the very close taxonomically related species A. alternata and A. tenuissima. Thus, this rapid, sensitive, and specific detection tool can be used to assess Alt a 1 exposure levels and to inform the implementation of the appropriate public health measures.

Monitoring of occupational and environmental aeroallergens-- EAACI Position Paper. Concerted action of the EAACI IG Occupational Allergy and Aerobiology & Air Pollution

Exposure to high molecular weight sensitizers of biological origin is an important risk factor for the development of asthma and rhinitis. Most of the causal allergens have been defined based on their reactivity with IgE antibodies, and in many cases, the molecular structure and function of the allergens have been established. Significant information on allergen levels that cause sensitization and allergic symptoms for several major environmental and occupational allergens has been reported. Monitoring of high molecular weight allergens and allergen carrier particles is an important part of the management of allergic respiratory diseases and requires standardized allergen assessment methods for occupational and environmental (indoor and outdoor) allergen exposure. The aim of this EAACI task force was to review the essential points for monitoring environmental and occupational allergen exposure including sampling strategies and methods, processing of dust samples, allergen analysis, and quantification. The paper includes a summary of different methods for sampling and allergen quantification, as well as their pros and cons for various exposure settings. Recommendations are being made for different exposure scenarios.