The Blomia tropicalis allergens.
ABSTRACT Blomia tropicalis allergens are the most important mite allergens in tropical regions. Most of them only have 30-40% sequence identity with their Dermatophagoides counterparts and they share low IgE cross reactivity and exhibit different immunobiology. Unlike the pyroglyphid counterparts, Blo t 5 is the major allergen whereas Blo t 1 only has modest allergenicity.
Article: Arthropod allergens in urban homes.[show abstract] [hide abstract]
ABSTRACT: Dust mites, cockroaches, and pets (cats, dogs) are common in homes worldwide, and many species are the source of potent allergens which cause allergic diseases. These diseases are influenced by genetic predisposition and environmental exposure. Generally, the levels of house dust mite (Der p 1 and Der f 1) and cockroach (Bla g 1, Bla g 2) allergens are used as markers of indoor exposure to arthropods.This article reviews the findings of allergens Der p 1, Der f 1, and Bla g 1 in randomly selected urban households in Zagreb (Croatia) measured from 2006 to 2010 and compares them with exposure to arthropod allergens in other countries. In short, house dust mite allergen levels in Croatian homes are low, but exposure is common; Der p 1 was found in 73 % and Der f 1 in 83 % of the households. By contrast, exposure to cockroach allergen Bla g 1 was both low and uncommon (13 %). Exposure to multiple allergens associated with sensitisation and asthma was not frequent in urban homes in Croatia. However, further studies should include monitoring of both arthropod and pet allergens in high-risk populations in inland and coastal Croatia. They should also investigate a complex dose-response relationship between exposure and sensitisation/asthma development, especially in early childhood.Archives of Industrial Hygiene and Toxicology 04/2012; 63 Suppl 1:47-56. · 0.67 Impact Factor
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ABSTRACT: BACKGROUND: Blomia tropicalis is a dust mite and an important source of allergens in tropical regions. Up to now, the assays to diagnose atopy to this mite use whole body extract as antigens. However, anti-B. tropicalis IgE antibodies cross-react with Ascaris lumbricoides antigens, hindering the diagnosis of allergy to this mite. In this study, B. tropicalis recombinant allergens were evaluated with the purpose of developing an immunodiagnostic assay for allergy to this mite with greater specificity than those commercially available. METHODS: Two B. tropicalis allergens (Blo t 5 and Blo t 21) were cloned into a plasmidial expression vector, expressed in Escherichia coli and purified by affinity chromatography. Sixty-three sera containing anti-B. tropicalis extract (BtE) IgE antibodies were used to investigate IgE reactivity to the recombinant Blot 5 and 21 allergens. Inhibition assays with 20 sera pre-adsorbed with A. lumbricoides extract were performed using rBlo t 5, rBlo t 21, and BtE as antigens. All the assays were carried using indirect ELISA. RESULTS: Eighty-two point nine percent and 80.0 % of the sera with anti-BtE antibodies from 35 children reacted with rBlo t 5 and rBlo t 21, respectively, whereas 92.8% and 89.3% of the 28 sera with anti-BtE antibodies from adult asthma patients reacted with the same allergens, and 96.4% of these sera reacted with a mixture of rBlo t 5 and rBlo t 21. In an inhibition ELISA, the absorption of sera by A. lumbricoides extract affected less the reaction with rBlo t 5 and rBlo t 21 than with BtE. CONCLUSIONS: The rBlo t 5 and rBlo t 21 allergens contain important epitopes recognized by IgE antibodies of individuals allergic to B. tropicalis antigens. Moreover, the assays using the recombinant allergens had lower IgE cross-reactivity with A. lumbricoides antigens, a fact which would confers higher specificity to serodiagnostic assays than the crude mite extract. However, additional recombinant allergens should be evaluated in order to reach the same sensitivity of the commercially available assays based on mite extract.BMC Immunology 02/2013; 14(1):11. · 2.61 Impact Factor
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ABSTRACT: One of the many aspects of the relationships between parasite infections and allergic diseases is the possibility that allergens from parasites enhance the TH2 responses, especially IgE production, in allergic diseases such as asthma. In this review we discuss about the allergenic composition of the nematode Ascaris lumbricoides and their potential impact on allergy sensitization and asthma pathogenesis and prevalence in populations living in the tropics and naturally exposed to both, mite allergens and helminth infections.World Allergy Organization Journal 05/2011; 4(5):77-84.