Asthma Genetic and Gene-Environment Interaction in Asthma Development

asthma genetics
The genetic basis of asthma heritability has been extensively studied and the studies are yielding some understanding. There is, as yet, no set genetic pattern that predicts presence of asthma or defines it severity. There are usually reasons or risk of asthma factors that makes someone susceptible to asthma and respiratory allergy problems. Asthma doesn’t just happen randomly to anyone without asthma gene factors risk factors.

Let’s consider some asthma risk factors and see how they increase the chance that a individual will have the asthma signs or symptoms of cough, wheezing, as well as shortness of breathing associated with the disease. After determining your personal risk factors for asthma, decide on the ones you can control as well as try to make some lifestyle changes. Avoidance of the risk factors you can control is important in preventing asthma symptoms. While you cannot change your own gender to family history, you can avoid smoking with asthma, breathing polluted air, and obesity. Take control of your asthma by controlling the asthma risk factors. By understanding all of the risk factors, you are able to prevent to control your asthma.

Genetic factors cannot explain the rise in asthma prevalence, morbidity, or mortality. However, a small change in the prevalence of relevant environmental exposures could explain a significant rise in disease prevalence among genetically susceptible individuals. Gene-environment interaction, defined as the co-participation of genetic and environmental factors, is particularly relevant to the etiology of asthma morbidity, especially in individuals who experience a disproportionate burden of environmental exposures. Relevant exposures include smoking, stress, nutritional factors, infections, allergens, and occupational asthma exposures. In addition, racial/ethnic variability in the distribution of genetic polymorphisms can potentially modify the response to pharmacotherapeutic agents, such as the ß 2 -adrenergic receptor. A genetic polymorphism in the ß 2 -adrenergic receptor gene has been associated with asthma severity, as well as with the susceptibility to develop asthma among individuals who smoked.

Childhood asthma happens more frequently in boys than in girls. It is still not known precisely why this occurs even though some experts find a young male’s airway size is small compared to the female’s airway, that may contribute to increased risk of wheezing after a cold or perhaps other viral infection. Around age 20, the ratio of asthma between people is the same. At age 40, more females than men have adult asthma.

The inherited genetic makeup predisposes you to having asthma. In fact, it’s thought that three-fifths of all asthma cases are hereditary. Based on CDC report, if a person has a parent with asthma, there is 3 to 6 times more probably to develop asthma than someone who does definitely not have a parent with asthma.

Allergic Responses Prevention: Regulatory T Cells (Treg)

Regulatory T Cells
The induction of immune tolerance and specific immune suppression are essential processes in the control of immune responses. Regulatory T cells (Treg) play a central role in immune control in the periphery. Two broad categories of Treg have been described: naturally occurring Treg that are present in all individuals and antigen-induced Treg that secrete inhibitory cytokines such as interleukin (IL)-10 and/or transforming growth factor (TGF)-ß. (more…)

Anti IgE Therapy Tolerability with Omalizumab Therapy in Allergic Asthma Patients

Anti IgE Therapy
Anti-IgE therapy could be particularly beneficial for patients with concomitant asthma and rhinitis as it targets a common factor in the two diseases. Omalizumab is significantly more efficacious than placebo in preventing asthma exacerbations and in improving disease-related quality of life scores when added to standard asthma and rhinitis therapies. (more…)

Repeated Dosing Effects Of Mediator Antagonists in Inhaled Corticosteroid-Treated Atopic Asthmatic Patients

Treating allergic rhinitis may have a downstream effect on concomitant asthma and this may be due to attenuation of the underlying inflammatory process.

Fexofenadine and montelukast exhibited additive effects to moderately high doses of inhaled corticosteroids when used as add-on therapy in the treatment of patients with persistent atopic asthma. (more…)

The Canadian Childhood Asthma Primary Prevention Study

Avoidance of any one of the individual risk factors associated with childhood asthma has not been successful in preventing its development. The purpose of this study was to determine the effectiveness of a multifaceted intervention programme for the primary prevention of asthma in high-risk infants at 7 years of age. Five hundred and forty-five high-risk infants with an immediate family history of asthma and allergies were prospectively randomized into intervention and control groups pre-natally. (more…)

Atopic Dermatitis Risk Factors in Children at 3.5 Years Of Age

Atopic Dermatitis Children
The prevalence of atopic dermatitis is increasing in Western societies. The hygiene hypothesis proposes that this is due to reduced exposure to environmental allergens and infections during early life. The authors examined factors associated with a diagnosis of atopic dermatitis at 3.5 years of age, especially those factors implicated by the hygiene hypothesis. The Auckland Birthweight Collaborative study is a case–control study of risk factors for small-for-gestational-age babies. Cases were born at term with birth weight at or below the 10th centile; controls were appropriate for gestational age, with birth weight above the 10th centile. (more…)

Allergy Skin Testing to Determine Allergies Causes

Allergy Skin Test
Allergy skin testing is probably the most susceptible and practical way to monitor for existing allergy sensitivity. Biological extracts of aeroallergens such as trees, dust mites, weeds, cockroaches, molds, and animal danders are offered for allergy testing. The most common and approved way to test is by putting a drop of antigen on the surface area of the patient’s skin and scratching or skin prick test with a lancet or sharp object. The most essential ancillary test to confirm the diagnosis of allergy is the skin test, which is the gold standard in this respect. The skin test final results must be viewed in light of the history to decide the importance of a positive test. (more…)

House Dust Mite Allergy Prevention With Dust Mite-Impermeable Covers

House Dust Mite Allergy
To prevent the development of allergy, allergen avoidance has to be instituted before sensitization has occurred. The specific type of aero allergens may vary depending on the climatic and economic situation. For example, House Dust Mite is the most important allergen in humid climates and pet allergens assume importance in cold countries, while cockroach allergen is the major sensitizing agent in crowded, inner city areas. Several large prospective studies have instituted House Dust Mites avoidance measures during pregnancy, at birth and later in childhood, and assessed children for asthma and allergic manifestations. (more…)

Allergen Exposure And The Development Of Atopic Sensitization

There is much controversy as to the role of allergen exposure for the development of atopic sensitization towards this allergen. While in some studies, a clear, almost linear dose-response relation between allergen exposure and sensitization has been found, others described a bell-shaped association with higher levels of exposures relating to lower rates of atopic sensitization. Part of the discrepancy may relate to the type of allergen, since mostly cat but not house dust mite allergy allergen exposure has been shown, in some studies, to exert protective effects at higher levels of exposure. (more…)

Allergy and Immune System: Living with Allergies & Immune Disorders

By definition, allergy is a condition where a person has hypersensitivity to an environmental, drug, or food antigen (allergen) caused by an altered or unusual immune system reaction to the antigen.

Allergenic foods can impact the lungs when an allergic reaction individual inhales food particles that may have been released when the food was cooked or that were dispersed in aerosol form. Allergy to the allergens in cooked food has been reported by highly allergic patients who were exposed to their allergenic foods (say, fish, shellfish, or eggs) in an enclosed area (for example, a restaurant dining room) or during meal preparation. Most cases of asthma triggered by aerosolized food allergens involve adults engaged in specific occupations that regularly expose them to the allergens. In contrast, most cases of asthma in children are triggered when the allergen is eaten, not inhaled.

Many experts believe that if a baby can be protected from becoming sensitized to the most highly allergenic foods when their healthy immune system and the digestive tract are in the most vulnerable stage for allergy to develop, the incidence of lifelong food allergy and potentially life-threatening anaphylactic reactions to foods will be reduced and hopefully entirely prevented. When a baby has been identified to be at risk for developing allergy, measures to reduce allergic sensitization might be implemented at birth and the problems associated with future food allergy may be significantly reduced. However, as we shall see in later discussions, experts disagree on the best way to avoid this early allergic sensitization.

The reaction of asthmatics to these chemical compounds is not an allergy, but is more correctly described as allergy intolerance because the initial response is not a triggering of the immune system. The process involves an increase in the level of the inflammatory mediators that are responsible for the bronchospasm of asthma. These mediators include histamine and leukotrienes. They are released during the reaction to an allergen, and cause the muscular contractions that result in the difficulty in breathing and wheezing that are typical of asthma. By inhibiting (or turning off) other types of mediators, the chemicals in the food additives cause an increase in the level of antihistamine and leukotrienes. This results in increased bronchospasm, and a definite worsening of the asthma symptoms.

Oral allergy syndrome is an allergic reaction to food that is confined to the oral cavity (i.e., to the lips, and around the lips, roof of the mouth, tongue, hard and soft palate, and uvula) and adjacent structures. It differs from other food allergy in that its symptoms do not appear in any other location in the body, and always accompany respiratory allergy to inhaled allergens of plants, particularly plant pollens. Of course, symptoms in the mouth, throat, and upper respiratory tract can be part of a generalized reaction to foods, but in this case they are more accurately described as oral allergy symptoms. The term oral allergy syndrome applies specifically to pollen allergy (pollinosis) accompanied by reactions to certain raw foods when they are in direct contact with oral tissues. Individuals with Oral allergy syndrome typically have hay fever symptoms caused by allergies to trees, grasses, and weeds. They experience irritation in the mouth (lips, tongue, roof of the mouth) and sometimes the throat after eating specific types of raw fruits, vegetables, and sometimes nuts.

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