Have you heard of these new methods for preventing and treating allergic diseases? Professor Cheng Lei shares

Allergic reaction is defined as the body's inappropriate immune response to harmless substances in the environment, also known as allergic reaction, and the group of diseases caused by it is called "allergic diseases". Allergic diseases are extremely common diseases in the world and are listed by the World Health Organization as one of the three major diseases to be prevented and treated in the 21st century.

According to statistics from the World Allergy Organization, 30% to 40% of people worldwide suffer from allergies. The incidence of allergic diseases in China continues to rise, and allergic reactions occur in people of all ages. In order to spread the characteristics of allergic diseases and emerging prevention and treatment methods to the majority of doctors, and to look forward to future scientific research development trends, Kangxun.com invited Professor Cheng Lei, Director of the Department of Otolaryngology and Director of the Allergy Diagnosis and Treatment Center of the First Affiliated Hospital of Nanjing Medical University, to interview him on the theme of "The Current Research Status and Future Development Direction of Allergic Diseases" in order to help the clinical diagnosis and treatment of doctors. The essence of the interview is now compiled for readers.

Professor Cheng Lei, The First Affiliated Hospital of Nanjing Medical University

Expert Profile

Cheng Lei, Doctor of Medicine, professor, chief physician, doctoral supervisor, and postdoctoral co-supervisor.

Director of the Department of Otolaryngology and Allergy Diagnosis and Treatment Center of the First Affiliated Hospital of Nanjing Medical University (Jiangsu Provincial People's Hospital), he has profound attainments in the mechanisms and clinical diagnosis and treatment of upper airway allergy and inflammation.

He is currently the incoming chairman of the Allergy Branch of the Chinese Medical Association, vice chairman and secretary-general of the Allergy Science Branch of the China Medical Health International Exchange Promotion Association, standing member of the Allergy Prevention and Control Professional Committee of the Chinese Preventive Medicine Association, and director of the Allergy Medical Equipment Committee of the World Allergy Organization.

1. The incidence of allergic diseases is high, and environmental factors play a leading role. Professor Cheng Lei pointed out that allergic diseases are also called allergic diseases. Patients are too sensitive to the external environment and produce specific immunoglobulin E (IgE) to certain allergens in the body. Such patients have a genetic tendency to allergic reactions. IgE sensitivity can lead to the following typical allergic diseases: allergic rhinitis, allergic asthma, atopic dermatitis and eczema, allergic conjunctivitis, food allergies, drug allergies, severe allergic reactions and anaphylactic shock. Among them, allergic rhinitis and asthma caused by allergens such as pollen, dust mites, fungi and pet dander are more common. Faced with the increasing incidence of allergic diseases year by year, Professor Cheng Lei introduced the following two pathogenic factors.

1. Genetic factors

Allergic diseases are systemic and systemic diseases with a certain degree of heredity. Studies have shown that if both parents do not have allergic diseases, the probability of their children suffering from allergic diseases is 20% to 40%; if one parent has an allergic disease, the probability of passing it on to their children is 40% to 60%; if both parents have allergic diseases, the probability of their children suffering from allergies can be as high as 80% or more. However, although allergic constitutions can be inherited, specific allergens are environmental factors and are not hereditary.

2. Environmental factors

In modern life, environmental factors have become the dominant factor in the onset of allergic diseases. After birth, newborns are exposed to various allergen environments. As the exposure and contact time increases, the human immune system will undergo a series of changes. In this case, people with allergic constitutions cannot tolerate allergens in the environment, and will develop allergic diseases such as rhinitis, asthma, dermatitis, and eczema.

In the past 30 years, the environment around the world, especially in China, has undergone tremendous changes. In terms of the macro environment, although air pollution has improved after rectification, it is still in a relatively serious state overall. With the continuous acceleration of industrialization, urbanization, and globalization, people's pace and way of life are constantly changing, the pressure of study, work and life is constantly increasing, and the variety of food and processing technology are increasing. As a result, many people who were not allergic before may gradually have allergic constitutions, and the number of potential allergic people is constantly expanding. In terms of the micro environment, with the improvement of living conditions, many home decorations bring more volatile chemical stimulation, which also catalyzes and accelerates the development of allergic diseases in the respiratory tract, while stimulating changes in the human immune system.

In summary, the interaction between heredity and environment leads to allergic diseases. However, the reason why the incidence rate is increasing year by year is mainly due to environmental factors. Therefore, more attention should be paid to environmental factors, and effective measures should be taken to improve the environment, reduce exposure to allergens, and prevent and treat allergic diseases from the source.

2. Three issues need to be paid attention to in allergen testing Professor Cheng Lei introduced that for allergic diseases, the diagnosis mainly relies on the patient's medical history, clinical manifestations, and allergen testing. The final diagnosis depends on allergen testing to find the real allergens, as well as the impact of allergens on the human body and the correlation with clinical symptoms. Clinically, allergens are mainly divided into inhaled allergens, ingested allergens, contact allergens, injected allergens, and self-tissue antigens. At present, many people believe that allergen testing is "ineffective" and missed diagnoses occur frequently. In response to this phenomenon, Professor Cheng Lei gave a corresponding answer.

1. Clinical joint application of allergen detection methods

At present, the methods recognized at home and abroad for allergen detection are mainly in vivo tests and in vitro tests. In vivo tests include skin prick tests and patch tests, and in vitro tests are to take blood from patients for ex vivo testing. Clinically, many people believe that in vitro and in vivo tests are closely related, so only one of them is sufficient. However, for allergic diseases with unclear diagnosis, conducting both in vivo and in vitro tests at the same time and comprehensively evaluating the test results will be more clinically valuable and improve diagnostic accuracy.

2. It is better to test for more types of allergens than to test for more types of allergens

Some people believe that the more types of allergens a patient is tested for, the better. But in fact, because the types of allergens in nature are complex and the detection reagents are limited, it is impossible to find out all the allergens. Through clinical data analysis, there are currently 8 to 16 types of airborne allergens and food allergens with a high positive rate in the test. Therefore, doctors can conduct tests based on the main allergen spectrum in the area, avoid blindly pursuing types and quantities, improve detection efficiency, and save medical resources.

3. Evaluate the scientificity of different testing methods

In addition to the commonly used skin prick test in clinical practice, serum IgE testing in the laboratory is also commonly used, and a large number of instruments and equipment have also entered hospitals at all levels. However, many instruments and equipment have different working principles, so we must also pay attention to whether different testing methods are scientific and comparable to ensure the accuracy of the interpretation of test results. In addition, for allergen-specific IgE testing, qualitative or semi-quantitative testing methods were used in the past, but full quantitative testing can achieve accurate diagnosis, the purpose of which is to better carry out allergen-specific immunotherapy, also known as "desensitization therapy."

3. Mesenchymal stem cells (MSCs) therapy is promising for the treatment of allergic diseases. MSCs are mainly derived from bone marrow, fat and umbilical cord. In addition to self-renewal and multidirectional differentiation capabilities, MSCs also have immunomodulatory, anti-inflammatory and tissue repair functions, and are increasingly widely used in clinical applications. In the field of allergic diseases, related research is still in the preclinical stage, using animal experiments to prove the therapeutic value of MSCs for allergic diseases, especially in allergic asthma, rhinitis and conjunctivitis, and great research progress has been made. At the same time, the combination of MSCs and certain traditional Chinese medicines is believed to have the potential to further improve the efficacy.

Professor Cheng believes that in the future, researchers should conduct in-depth exploration of MSCs therapy in terms of immunological mechanisms, related adverse reactions, and long-term efficacy. In the future, this therapy will likely make greater progress and be truly applied in the clinical treatment of allergic diseases.

4. Specific immunotherapy for food allergy Food allergy is similar to other allergic diseases, and the prevalence is gradually increasing. The main allergens of food allergy include milk, eggs, soybeans, peanuts, fish and shrimp, beef, mutton, seafood, etc. Specific immunotherapy for food allergy is the only treatment method for the cause of allergic diseases in clinical practice so far, and it has both preventive and therapeutic significance. Professor Cheng introduced two specific immunotherapies for food allergy in the interview.

1. Oral immunotherapy

Oral immunotherapy has made great progress in the treatment of food allergies in recent years. For example, studies have found that children and adolescents aged 4 to 17 years old who continue to receive oral immunotherapy with peanut allergen powder for more than one year show sustained safety and effectiveness, and sustained immunomodulatory effects can still be observed in the second year of treatment.

2. Epidermal immunotherapy

Epidermal immunotherapy is a method of delivering food allergen extracts directly to the superficial layer of the skin, gradually training the body's immune system until the optimal maintenance dose is reached, so that the patient can develop tolerance to the allergen. Over time, when the patient is exposed to a specific allergen (such as peanuts), there will be no clinical symptoms, and food allergy patients will be protected from severe allergic reactions that are life-threatening.

Professor Cheng believes that the current clinical progress in immunotherapy for food allergens such as milk, eggs, and peanuts is mainly focused on children. Its efficacy in treating adult food allergies needs further clinical observation in the future in order to cover all age groups.

5. Future prospects for diagnosis and treatment of allergic diseases 1. Epidemiological studies

Epidemiological surveys of allergic diseases can help us understand the overall trend of the disease and provide reference data for health administrative departments to formulate better prevention and control strategies. In recent years, the prevalence of allergic diseases in China has been changing over time. Some past data do not represent the current situation. We need to create conditions to conduct new regional or national epidemiological surveys.

2. Pathogenesis research

At present, the immunological and genetic mechanisms of allergic diseases are not fully understood. Therefore, only by conducting basic research on allergic reactions from the perspective of pathogenesis can we have a deeper understanding of the nature of the disease, find prevention and control targets, achieve precise treatment at the molecular level, and improve clinical treatment effects and safety.

3. New drug research and development

Allergic diseases are currently treated with first-line drugs such as glucocorticoids, antihistamines, and leukotriene receptor antagonists. Although relatively good results have been achieved, it is still a long way from a cure. With the in-depth study of the pathogenesis, further breakthroughs in biological targeted therapy may be possible in the future. At present, anti-IgE therapeutic drugs such as omalizumab and biological agents targeting certain cytokines have been used in clinical practice.

4. Research on integration of traditional Chinese and western medicine

Based on China's specific conditions, we should further strengthen the research on the diagnosis and treatment of integrated Chinese and Western medicine. In particular, traditional Chinese medicine has a unique understanding of allergic diseases. The "differentiation" of Chinese medicine and the "evidence-based" of Western medicine need to be organically combined to create a new method of integrating Chinese and Western medicine for the treatment of allergic diseases.

Reviewer: Cheng Lei, First Affiliated Hospital of Nanjing Medical University

Rehearsal丨Yang Yining