Genetic Association of IL-17 rs2275913G/A or 197 A>G Gene Polymorphism in Patients with Respiratory Allergies in Basra Governorate / Iraq

Abstract

Allergies and asthma are major global health problems in many countries and cases of respiratory diseases have increased around the world in recent years, as epidemiological studies and many recent studies have shown that allergic rhinitis has a significant impact on asthma and that its treatment may affect asthma control as the majority of asthma patients were suffering from allergic rhinitis and it is an increased risk factor for asthma ⁽¹⁾ These diseases occur as a result of interaction between environmental causes and genetic factors and the multiplicity of genetic forms (Polymorphism) of genes of the most important genetic factors, which is intended to vary in the sequence (sequence) of deoxyribonucleic acid (DNA) found between individuals of the same type and is the most common variation of genetic diversity found throughout the human genome  It can also be expressed as the presence of two or more alternative forms of allele in an individual's genome, resulting in characteristic phenotypic patterns in the same population and frequency in the population of at least 1% ^(1,2) Continuous or repeated exposure to harmful environmental factors leads to allergic diseases, which later develop into asthma, where epithelial cells stimulate the release of a group of interleukins that are considered an inflammatory response to allergens ⁽³⁾  Where the term InterLeukin (IL) is a description of a group of cytokines (Cytokines), which are cellular motor proteins with complex immune functions that are manufactured by different cells, but mainly by CD 4+ cells of T cells, and the activity of interleukins varies according to their members, but in general they stimulate the growth, reproduction, maturity, migration, differentiation and development of T and B cells and other blood cells,  These proteins play an important role in the differentiation and activation of immune cells, the term interleukin (IL) was first described in 1979 in a letter to the editor of the Journal of Immunology to describe a number of leukocyte secreting molecules (Leukocytes) and also described as originating from lymphocytes and therefore sometimes

referred to as lymphokins. ^(1,4) Allergy in general is an  abnormal immune reaction that occurs as a result of an antigen or foreign body, and allergy is not a disease but a series of immune reactions that lead to known symptoms of allergy. Allergic diseases are caused by allergens, whose chemical composition affects the human body through their effect on the immune system, which leads to an allergic reaction Asthma is defined as a chronic inflammation of the airways in which many cells and cellular elements play a role. Chronic inflammation is associated with airway overresponse, which leads to frequent episodes of wheezing, chest tightness, shortness of breath and coughing, especially in the early morning and at night.