Electronic Journal of Biology

Description

Allergic diseases are a widespread global health concern, affecting millions of individuals each year. These conditions, which include allergic rhinitis, asthma, food allergies and atopic dermatitis, are characterized by an exaggerated immune response to harmless environmental substances such as pollen, dust mites or specific foods. The immune system, which typically defends the body against pathogens, mistakenly identifies these benign substances as harmful invaders, triggering an inflammatory response. Over time, this misguided immune reaction can lead to chronic sympt- oms and even life-threatening conditions, particularly in the case of anaphylaxis. Effective treatment of allergies, therefore, hinges not only on alleviating symptoms but also on modulating the immune system to restore balance and prevent long-term damage. In this article, we describe the different approaches to allergy treatment, focusing on immune system modulation as a key strategy in achieving effective management and long-term relief.

Allergy treatments

Current treatments for allergies primarily focus on alleviating symptoms rather than addressing the underl- ying immune dysfunction. These include antihistamines, corticosteroids, decongestants and leukotriene inhibi- tors. Antihistamines work by blocking the histamine receptors, preventing the histamine-induced symptoms of itching, sneezing and swelling. Corticosteroids, often delivered through nasal sprays or inhalers, reduce inflammation in the airways and skin, providing relief for conditions like asthma and rhinitis.

However, these treatments, while effective in the short term, do not address the root cause of the immune response. They merely suppress the symptoms without altering the immune system's tendency to overreact. This makes them less effective in preventing the progression of allergic diseases or long-term relief. For instance, individuals with asthma may experience recurrent flare-ups despite regular use of corticoste- roids. This limitation has prompted the development of more advanced treatments aimed at modulating immune system activity.

One of the most encouraging strategies for effective allergy treatment is immunotherapy, which seeks to retrain the immune system and induce long-term tolerance to allergens. This approach is based on the idea of gradually desensitizing the immune system to the specific allergens that trigger allergic reactions.

Allergen Specific Immuno-Therapy (SIT) involves the administration of small, gradually increasing doses of the offending allergen, either through sublingual tablets or subcutaneous injections. Over time, this helps to shift the immune response from a Th2-dominated (pro-inflammatory) response to a more balanced Th1 (regulatory) response. This process, known as immune tolerance, reduces the production of Immunoglobulin E (IgE) antibodies and the activation of mast cells, leading to fewer allergic symptoms and a diminished response to allergens.

Immunotherapy is a well-established treatment for conditions like allergic rhinitis and allergic asthma, with research demonstrating its long-term efficacy even after the therapy is discontinued. Recent advancements in SIT include the development of modified allergens and adjuvants to enhance the immune response and improve treatment outcomes. However, the treatment is not without risks and it is generally only recommended for individuals with severe allergies who do not respond to conventional medications.

Biologic drugs

Biologic therapies have emerged as a new frontier in allergy treatment, particularly for individuals with severe, persistent allergic diseases. These drugs are designed to target specific molecules involved in the immune response, providing a more targeted and effective way to modulate the immune system. One such biologic is omalizumab, a monoclonal antibody that binds to IgE, preventing it from interacting with mast cells and basophils. By inhibiting the allergic cascade at an early stage, omalizumab can reduce the frequency and severity of allergic reactions. Omalizumab has shown promising results in treating allergic asthma, chronic urticaria (hives) and allergic rhinitis. Other biologics, such as mepolizumab and benralizumab, target different components of the immune system, including interleu- kins involved in inflammation. These biologic treatments offer a promising option for patients who have not responded to conventional therapies and are at risk of severe allergic reactions.

While biologics are a significant advancement in allergy treatment, they are expensive and typically reserved for individuals with severe, uncontrolled allergies. Further- more, the long-term safety of these treatments is still being evaluated, though early research suggests that they offer a highly effective and targeted approach to immune modulation. Allergic reactions are initiated when the immune system recognizes an allergen, such as pollen, pet dander or certain foods, as a threat. In response, the body produces Immunoglobulin E (IgE) antibodies that bind to mast cells and basophils, which are types of white blood cells. Upon subsequent exposure to the allergen, these antibodies trigger the release of histamine and other inflammatory mediators, leading to symptoms such as itching, swelling, redness and difficulty breathing. This overactive immune response is the attribute of allergic diseases and is often exacerbated by environmental factors like pollution and climate change. The immune system’s involvement in allergic reactions is complex, as it surround both innate and adaptive immunity.

The innate immune system, which provides a rapid but nonspecific response to pathogens, is involved in the initial detection of allergens. On the other hand, the adaptive immune system, which is more specific and memory-driven, plays a central role in the development of allergic sensitivities. Modulating both of these arms of the immune system is imoportant for effective allergy treatment.