ABSTRACT
Mite species that inhabit house dust or storage foods are source of allergens capable of sensitizing and inducing allergic symptoms. The most important and relevant species are Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis, Euroglyphus maynei, and Lepidoglyphus destructor. More than 30 groups of allergens have been described. The allergens have well-defined biological functions such as enzymes, lipid binding activity, among others. This biological and functional activities are used to group them in different allergen groups. Allergens, such as those contained in groups 1 and 2, are considered major allergens based on their frequency of specific IgE recognition by sensitized patients, amount of specific IgE directed to them, and relative content in mite extract. Cross-reactivity is a common feature among mite allergens, especially in those from taxonomically related species, and may be the cause of polysensitization occurring in some mite-allergic individuals. Structural and sequence homology among mite allergens support the cross-reactivity among mites, other arthropods, and helminths. Allergens homologous to tropomyosin and glutathione-S-transferase are involved in the cross-reactivity between mites, insects, and parasites. The protease activity of mite allergens may induce a range of inflammatory effects modulating the adaptative immune response. Genome-wide association studies and gene expression analyses revealed associations between genes of major histocompatibility complex and others with the IgE immune response to mite allergens. The epigenome might also influence the susceptibility to mite sensitization.
