[Frontiers in Bioscience E3, 51-64, January 1, 2011]

Allergy in the tropics: the impact of cross-reactivity between mites and ascaris

Luis Caraballo1, 2, Nathalie Acevedo1, 2

1Institute for Immunological Research, University of Cartagena, Cartagena, Colombia, 2Foundation for the Development of Medical and Biological Sciences, Fundemeb, Cartagena, Colombia

TABLE OF CONTENTS

1. Abstract
2. Introduction
2. Introduction
3. Allergic diseases in tropical regions
4. IgE cross reactivity between domestic mites and Ascaris
5. The allergenic composition of Ascaris and mites
5.1. Tropomyosin, an invertebrate pan-allergen
5.2. The Glutathione S Transferase Superfamily
6. The influence of parasite infections on allergic diseases: epidemiological studies
7. The influence of parasite infections on allergic diseases: experimental analyses
8. Mites and nematode co-exposure: genetics and possible influences of cross reactivity in the allergic response
9. Impact of cross reactivity in the diagnosis of ascariasis: ABA-1 as a nematode specific marker of infection
10. Concluding remarks and perspectives
11. Acknowledgments
12. References

1. ABSTRACT

Allergic diseases and nematode infections such as ascariasis are important health problems in underdeveloped tropical countries. The co-exposure to Ascaris lumbricoides and the domestic mites Blomia tropicalis and Dermatophagoides pteronyssinus induces a strong Th2 and immunomodulatory responses that can modify the natural history of both diseases. An associate phenomenon of these particular environmental conditions is cross reactivity between mite and Ascaris allergens. We demonstrated a high IgE cross reactivity between the allergenic extracts from both sources and that several already known allergens like tropomyosin and glutathione-s-tranferases are involved. Although this cross reactive antibody response has not been completely analyzed, there are clinical and experimental evidences suggesting that it could be an important component of the complex interactions between ascariasis and mite allergy. For example, it may affect the specificity of serological IgE tests for diagnosing both ascariasis and allergic diseases and, in consequence, the results of epidemiological surveys evaluating the predisposing or protecting role of ascariasis on allergy. In this review we discuss the potential role of cross reactivity on several aspects of allergy in the tropics that have been the matter of a number of investigations, some of them with controversial results.