Geography of house dust mite allergens

Abstract

Objective: To consider how the different distribution of house dust mites and their species in different geographical locations affects the allergens in the environment and their use. Data sources: Data were obtained from Medline, Genbank and library and web searches. Study selections: A comprehensive description of the genetic variations of allergens is given. The distribution of house dust mites is illustrated with publications that either make pertinent observations or would be useful for a broad appreciation of their geographical distribution. Results: The review identifies regions where glycyphagid house dust mites have been found and the distribution of the pyroglyphid Dermatophagoides spp. The antigenic differences the allergens of D. pteronyssinus and D. farinae are outlined and how this should affect optimal allergen usage in different regions. The allelic variations within the major allergens of Dermatophagoides sp. are similarly presented. Conclusions: While there is a broad knowledge of the distribution of different species of house dust mites, regions that require further examination have been identified and there are examples of incorrect use of allergens for different regions. The extension of allergy research and practice into new regions will benefit from allergen formulations designed for regional use. Specific knowledge of the allergens in the environments will be required to optimally implement some of the new molecularly-defined medicaments currently being developed for effective allergy vaccination and immunotherapy.