|Aleksandra Szczepankiewicz, Anna Bręborowicz|
Bronchial asthma and related allergic phenotypes are the most common chronic disorders, both in Poland and worldwide. According to the World Health Organisation (WHO), asthma affects about 100-150 million people worldwide, and the morbidity rate still increases. In Poland, asthma prevalence in adults is estimated at 5.4%, whereas in children it is over 8.6%, which means that asthma symptoms are noted in two millions of adults and nearly one million of children. The prevalence of asthma in our country continues to increase, particularly among children living in big cities.
One of the hypotheses explaining that increase of asthma and allergy in the past five decades is "hygiene hypothesis" which assumes that exposure to viral infections and bacterial endotoxins in the infancy stimulates the immune system to develop Th1 cells subpopulation, while absence of the environmental pathogens results in survival of the Th2 foetal phenotype responsible for the allergic response . Results of some studies suggest early childhood as a critical period in the development of allergy and asthma .
A number of chromosomal regions have been identified in genetic studies that are associated with asthma and allergy, while polymorphisms in candidate genes are related with increased susceptibility to allergic diseases. Increased risk involves polymorphisms in candidate genes participating in the systemic immunological response (such as cytokines, tumour necrosis factor) as well as changes in receptor and signalling molecules in genes that mediate systemic responses to pathogens (Toll-like receptors, CD14 receptor, eotaxins, glutathione transferase, uteroglobin, etc.).
Therefore, it seems essential to analyze genetically-related tendency to develop asthma and allergic diseases in combination with the environmental influence.
keywords: astma, predyspozycja genetyczna, polimorfizm, gen kandydujący, asthma, genetic tendency, polymorphism, candidate gene
pages: from 123 to 131
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