fungal allergic asthma
Introduction
Introduction to fungal allergic asthma Clinically, there has been more than 200 years of knowledge about fungal allergic asthma. In 1728, John Floyer reported a sudden onset of asthma when visiting a winery. In 1924, VonLeeuwen proposed that asthma patients in the Netherlands were caused by dampness. In the same year in the United States, Cadhan reported 3 cases of asthma induced by wheat rust. These findings are the prototype of fungal allergic asthma, 1928 in Germany. Dr. Hansen officially confirmed for the first time that 15% of asthma patients were positive for the skin test of Alternaria alternata and Penicillium antigen collected in the living environment, and confirmed that some of them were induced by inhalation of Alternaria or Penicillium spores. Asthma attack. In 1932, Tubs reported that a child with asthma developed symptoms after eating fermented food each time. It was suggested that yeast and candida are the cause of certain asthma patients. In 1934, Prince et al. observed the culture of fungi in the living environment of patients. It was found that when the fungus grew vigorously, the patient's asthma symptoms worsened. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific population Mode of infection: non-infectious Complications: pneumothorax, mediastinal emphysema, atelectasis
Cause
Fungal allergic asthma
(1) Causes of the disease
1. Fungal classification and its characteristics
There are many kinds of fungi and they are widely distributed. There are about 100,000 species in nature. Due to geographical and climatic factors, the types and contents of fungi in the atmosphere vary greatly. They are affected by living conditions and customs, and the concentration of indoor fungi. There are also great differences. There are hundreds of fungi that are highly sensitizing and have a large amount of airborne. The main cause of human sensitization is indoor fungi. Although the number of fungi in the air is extremely large and different, they are all It has the common characteristics of a branched nutrient structure with filaments, a nucleus and cell wall, and no chlorophyll. It is an organism that is typically sexually propagated and vegetatively propagated, containing polysaccharides and proteins, according to modern classification. The method of learning, the fungus is divided into 5 classes, and there are 4 classes related to allergies.
(1) zygomycetes: This class is a lower class of fungi, and is the least number of classes. Among them, the genus Mucor is the largest family in this class, the mucor, the root mold, the pear head in this family. Mildew, common mold, etc., are both pathogenic bacteria and important allergenic fungi that cause allergies.
1 The hyphae are mostly tubular, usually without a cross-section, with branches, and the hyphae diameter is large.
2 When asexually propagated, spores are produced in the sporangia.
The sporangia are usually born at the top of the vegetative hyphae or at the top of a special reproductive hyphae called a cystic stalk. In the early stage of the sporangia, it is filled with multinuclear protoplasm. When it develops, the whole protoplasm is split into Many small pieces, each of which develops into a cystic spore. The cystic spores are mainly transmitted by the wind. Under appropriate conditions, the spores germinate a germ tube and develop into a new mycelium.
3 When sexually reproducing, mating for gametes or gametophytes, then forming dormant spores and joining spores.
(2) Ascomycete: It is a relatively large class of fungi. From their complex structure, it is much more evolved than zygomycetes, and it is likely to evolve from zygomycetes, such as Chaetomium, which is common in the air. Pseudomonas aeruginosa, spore cavity bacteria and the like.
1 Most of the fruit bodies produced by the species contain ascus, which are mostly slender stick-shaped or cylindrical bag-like structures, a few are spherical, oval or rectangular, usually the ascus is a cavity, which forms ascospores, and also For the separation of the ascus.
2 There are a certain number of spores in the ascus, usually 8, but the number of spores is not exactly the same due to the different species. The size, shape, color and other characteristics of spores vary greatly. Generally, the characteristics of ascospores are used. The basis for the subgenus of Ascomycetes.
3 Asexual reproduction can be carried out by division, budding, rupture, powder spores, chlamydospores or conidia.
4 sexual reproduction is the combination of the nucleus of the two sexes, gathered in a cell, forming a mate, called the dual-nuclear phase, through the continuous binucleary cleavage to produce a number of binucleated cells, the diploid nucleus in the ascending sac After the combination, meiosis is performed immediately, producing 8 nuclei, thereby forming a typical 8 ascospores.
5 Many ascomycetes, only one sexual stage occurs each year, often encountered conidia stage.
(3) Basidiomycetes: This is the most advanced class of fungi, such as mushrooms, fungus, ganoderma lucidum and black powder fungus, rust fungi, etc., which belong to this class.
1 There are special spores, called burdens, there are 4 spores on the load, the quality of the spores, nuclear and meiosis occur in the burden, and the spores can be round, oval, elongated or dachshund. Shape, no pigment or pigment, light color, can be recognized when spores are piled up.
2 There is no obvious reproductive organ. The combination of the two sexes is the combination of undifferentiated hyphae or the combination of spores. When combined, only the quality is matched, no nuclear matching, the result is a binuclear cell phase, and combined with a special lock. The way to form new binuclear cells, the nucleus of the amphipathic nucleus before the formation of spores, and then meiosis, resulting in haploid spores.
3 asexual reproduction by means of budding, mycoplasma fission or the production of conidia and powder spores, black powder bacteria often produce conidia, its conidia are from both spores and mycelium budding Formed, rust produces uredospores, which are conidias in origin and function, and many other basidiomycetes also produce conidia. Some mycobacteria mycelium usually split into single cell segments, these mycelium The fragments are powder spores.
4 Sexual reproduction is achieved by somatic cell coordination or fertilization. In the cell-producing species, two monocyte hyphae are in contact with each other, the cell wall of the contact point dissolves, and one cell nucleates and enters another cell. Inside, to make it a dinuclear, this binuclear cell divides continuously to produce a dinuclear mycelium. In the species of basidiomycetes that produce powder spores, the complexation often occurs when the combination of powder spores and vegetative hyphae occurs. In short, The formation of the burden, the dinuclear mycelium and the lock combination is three typical characteristics of basidiomycetes.
(4) Deuteromycetes: This class is a group of conidia stages of ascomycetes and a few basidiomycetes that have not been found in the sexual stage. It also includes some known ascuses that have been described and named before the discovery of the sexual stage. The asexual stage of bacteria and basidiomycetes, such as Aspergillus, Penicillium, Verticillium, Alternaria, Trichoderma and the like.
1 They are only propagated by fragments of conidia or hyphae. Conidia are usually produced on conidiophores. The conidiophores have different forms. They can be produced from common vegetative hyphae. Any obvious organ, or can form a certain fruiting body, the most common fruiting body has conidia and conidia disk.
2 In their life history, only the asexual stage was discovered, so it is called a semi-known bacteria.
3 hyphae are separated, many are saprophytic bacteria, but many are extremely important to humans, and are parasitic bacteria that cause plant, animal and human diseases.
2. Investigation of airborne fax bacteria in the air
The investigation of fungi in the air is an important method to find out the species, quantity and seasonal distribution of common fungi in the air. This is of great significance for screening sensitized fungi and guiding the diagnosis and treatment of fungal allergy patients. The selection of the original strain is determined according to the investigation data in the air and the sensitization of the fungus. The most common, the most spore-spreading and the most sensitizing fungi in the air are separated and screened. The strains are cultured in the laboratory and can be prepared into various fungal allergen infusions for clinical diagnosis and immunotherapy.
It is generally believed that the fungal investigation is carried out synchronously with the exposure sheet and the exposure dish. Since the exposure investigation is difficult to observe and distinguish some small fungal spores, the investigation of the observation dish is also very important. Usually the investigation should last at least 1 year to be more comprehensive. Learn about the main sensitizing fungi in the area.
(1) Air exposure film and microscopic inspection counting method:
1 Exposure method: expose the glass slide (25mm × 75mm) coated with soft Vaseline adhesive in the air, put the glass coated with adhesive on the sampler, and take the film regularly in the air. After exposure for 24 hours, put a piece of glycerin gel stain on the retrieved glass slide, and cover the 22mm×22mm clean coverslip after micro-dissolving. Generally, the next day, the microscopic examination was performed.
(1) Air exposure film and microscopic inspection counting method:
1 Exposure method: expose the glass slide (25mm × 75mm) coated with soft Vaseline adhesive in the air, put the glass coated with adhesive on the sampler, and take the film regularly in the air. After exposure for 24 hours, put a piece of glycerin gel stain on the retrieved glass slide, and cover the 22mm×22mm clean coverslip after micro-dissolving. Generally, the next day, the microscopic examination was performed.
2 Mirroring counting method: When performing microscopy, place the slide on the microscope stage, move the pusher slowly from left to right, and then push the ruler up slightly to push the slide to a new one. The microscopic examination part, then move the pusher from right to left, and so on, in order to completely cover the coverage of the coverslip, detail the type and quantity of fungi, a hospital in 1989-08-01 ~ 1990-07- 31 Exposure of a glass coated with Vaseline Adhesive at 10 am every day, 24 h, add 1 drop of neutral gum, cover 22 mm × 22 mm coverslip, full cover glass microscopy, record fungal spores, hyphae The number of bodies was 365 sheets throughout the year. A total of 101,112 fungal spores were collected, 2,367 mycelial tablets, and 10,089,000 fungal spores were identified, with a total of 37 species.
(2) Air in the dish and microscopic inspection method:
1Induction method: expose the dish with disinfection medium (10cm in diameter) in the air for 3-5 minutes. The exposure location can be determined according to the needs. After the exposure is completed, the plate is placed at room temperature or in an incubator at 25 °C. Observe daily, record the growing colonies and identify their names. The plates should be placed at a fixed location. Gently pick and place when observing, prevent fungal spores from being shaken, causing contamination of the culture medium and affecting the accuracy of the survey count. Generally, weekly Or expose the dish once a month, the time should be consistent with the exposure, at least 1 year.
2 microscopic examination counting method: In order to prevent the growth of some fungi, it will soon grow over the culture dish and affect the growth of other fungi. Once the spores are formed, they should be separated and identified and recorded immediately. A colony is recorded as a fungus. The colonies and fungi species should be calculated separately. In our hospital, 11cm culture dishes, potato dextrose, Chua's, and Sha's three kinds of agar medium are used in the exposed area. Three fixed spots are placed in the front square and the ward of the hospital. Three dishes, once a month, once every day at 10 am, the dish was exposed for 3 minutes, cultured in a 25 °C biochemical incubator, observed daily, and the number of colonies was recorded until no new colonies appeared. The colonies were picked by direct compression or slide culture. Microscopically, the identified fungi were photomicrographed and transferred to a test tube agar slant culture and storage. The dishes were exposed 24 times a year, a total of 216 agar plates, and 3012 colonies were collected.
3. Allergenicity study of fungi
Fungi and fungal spores as an antigenic substance, its ability to produce antibodies in the human body is relatively low, may not produce exotoxin due to fungal and fungal spores, and no surface antigen exists; or a layer of chemically stable on the cell membrane of fungal spores The substance makes the antigen component in the cell difficult to release, so the function of stimulating the antibody is low. In clinical practice, the intensity and positive rate of the skin test of the fungal antigen infusion are significantly lower than that of the pollen antigen infusion.
The process of fungal-induced allergic reaction is similar to the process of induction of allergic reaction to tuberculosis. Therefore, when skin test is carried out with fungal antigen infusion, both rapid-acting phase skin reaction and delayed-onset skin reaction may occur, sometimes biphasic. Response, we have observed the skin test results of 75 cases of allergic conjunctivitis, the positive rate of fungal late phase reaction is significantly higher than the rapid response.
The so-called allergic fungi, mainly some plant pathogens and saprophytic bacteria, in the past, most people believe that the main antigenic active ingredient of fungi is present in fungal spores. Later, it was found that there are allergens in hyphae and spores, many laboratories at home and abroad. The allergen components of several fungi have been studied, including antigen purification, immunoassay analysis, etc. Gravesen analyzed by cross-radioelectrophoresis in 1979 and found that Alternaria alternata contains more than 10 antigenic components. In 1980, Yunginger et al. Biochemical analysis of Alternaria alternata revealed an antigenic glycoprotein called Alt-1 with a molecular weight between 25,000 and 50,000. Aukrust equalized the antigenicity of Mycobacterium fuliginea in 1979. Found to contain more than 60 protein components, of which 4 are the main antigenic determinants, the rest are secondary antigenic determinants, two of which are purified, molecular weights of 13000 and 25000, for 10 different species The antigenic comparison of the genus Mycobacterium sinensis showed that the content of major antigenic determinants in different germ lines varied greatly. In 1980, Kauffman et al. According to the analysis, it was found that the flora with long culture time was higher than that of the short culture period. After the sensation of Aspergillus fumigatus in Pepys in 1969, it was found that it not only induced specific IgE, but also produced specific IgG. To become an important basis for the pathogenesis of allergic bronchopulmonary aspergillosis by Aspergillus fumigatus, a hospital in Beijing began to conduct immunoelectrophoresis and agar diffusion assay on Penicillium, Alternaria, Aspergillus, etc. in 1984, and found some differences. In 1986, the P. chrysogenum antigen was initially isolated and purified. In 1986, Beijing Medical University conducted preliminary activity identification of Alternaria alternata allergen and found a more antigenic component. Reed found high antigenic crossover between Aspergillus fumigatus and A. Terreus, A. clavatus, A. niger, and A. flavos.
In short, a wide variety of gas-borne bacteria, widely distributed, is one of the important allergens for the induction of bronchial asthma, it is reported that the United States has now entered the market of commercial fungal allergen infusion preparations as many as 280 kinds, and China is currently used There are only 20 to 30 kinds of fungal antigens for clinical diagnosis and treatment. Therefore, in-depth separation and purification of allergens is an important task in the study of fungal allergology in China.
(two) pathogenesis
After the fungal spores enter the airway of normal people, the barrier function of the intact airway mucosal epithelium plays an important defense function against the inhaled fungal spores, and the fungal spores are rejected, and the phagocytosis of macrophages in the airway is also cleared. Inhaled fungi and their spores play an important role, so fungi rarely become pathogens, because the barrier of airway mucosal epithelium effectively limits the contact of fungal antigens with airway-associated lymphoid tissue, therefore, the specificity of fungi in the blood circulation The level of sexual IgE is usually low, and the precipitin is negative by two-way immunodiffusion and ELISA-IgG titration. For patients with atopic quality, when the airway is repeatedly exposed to fungal spores or mycelial antigens. At the same time that airway macrophages phagocytose fungi, the immune system in the airway also presents it as a foreign antigen, which can produce specific IgE against fungi and cause airway sensitization, which induces abnormalities in the respiratory tract. The reaction causes asthma attacks, Aspergillus, Penicillium, Rhizoctonia, Alternaria, Trichoderma, Mucor, Rhizopus, Pythium, Common head , Basidiomycetes and fungi such as Candida spores can be produced as an antigen-specific IgE, may cause allergic airway inflammation.
The incidence of fungal allergic asthma
1. Incidence profile
Due to experimental technical limitations and no corresponding diagnostic criteria, there is no exact data on the incidence of fungal allergic asthma at home and abroad. Since the clinical manifestations of fungal allergy are much more complicated than pollen allergy, it does not necessarily have It is obviously seasonal, and the cross-reaction between various fungi is very high. The incidence rate is statistically different. The positive rate of fungal skin test in hospitals in Beijing is 21%. The positive rate of fungal allergen skin test in China is as high as 70. %, the incidence of various occupational fungal allergies has increased in recent years. According to the US Census Bureau, the total agricultural population in the United States is more than 8 million, of which 1/4 are frequently exposed to cereals, and 1/2 to 3/4 of patients Exposure to grain dust, due to the long-term storage of dust in the valley dust, many of which cause fungal asthma, acute or chronic peasant lungs, etc., China's agricultural population is dozens of times more than the United States, and mainly by manual operation , fungal allergy must be a very important issue, in the future with agriculture, animal husbandry, brewing and fermentation, food processing, mushroom cultivation, pharmaceutical industry Exhibition, as well as the use of air conditioners in the living environment, an increase in closed buildings, are likely to lead to further increase in fungal allergy.
Jimenez Diaz and Sanchez Cuenca found that most of the patients who were allergic to indoor dust in Spain were mostly allergic to dust in the dust. In 1939, Wittich found that rust and black powder spores in the dust were the main sensitization of asthma patients in Minnesota. The pathogen, Bruce found that 15 of the 24 patients allergic to Alternaria alternata were consistent with the peak count of Alternaria alternata in the air. Since the 1970s, Reed and Salvaggio have separated and purified the antigens of sensitizing fungi. I have done a lot of work and made in-depth research on the occupational allergic reactions of various fungi. In 1983, Crook made a lot of discussion on the influence of Candida on human immune function and Candida allergy. In 1957, Beijing Regional Hospital began to carry out fungi. Clinical and laboratory studies of allergic reactions, over the past 30 years, through the clinical diagnosis and treatment of tens of thousands of patients and laboratory airborne fungal exposure, exposure dish culture surveys, the types of sensitizing fungi in China, the law of dispersion, Test methods, antigen preparation, fungal identification, strain preservation, antigen purification, etc. have done a lot of work, for the bronchial stagnation caused by fungi Asthma, hypersensitivity pneumonitis, alveolitis, allergic pulmonary bronchial aspergillosis have gained some practical experience, creating the necessary conditions for the comprehensive study of fungal allergies in the future.
2. Relationship between age and incidence of fungal allergy
The study found that the incidence of fungal allergy is closely related to the age of the patient. It is confirmed by a survey of 10 years as an age group that the incidence of fungal allergy is highest in the age group under 10 years old, usually the younger the age, allergic to fungi. The incidence is higher, and the sensitivity to fungi can decrease rapidly with age. This phenomenon is in sharp contrast with pollen allergy. The positive rate of various fungal skin tests in the younger age group is usually in comparison with the region. The types and contents of fungal spores in the air are relatively consistent, suggesting that the results of the investigation of fungi in the local air can be used as reference for fungal skin tests in children of younger age. Koivikko et al. confirmed that the incidence of allergic reactions to fungi in children with asthma is relatively high. The results are also consistent with the relatively high specific IgE titer of the radioactive allergen adsorption test in children's serum. Fungal antigens can sometimes pose a serious threat to patients with severe asthma and are an important asthma-inducing factor. Leading to asthma death in children and young people, Beaumont et al. skin test for fungal allergen extract in adult asthma patients Investigation, the positive rate of less than 5%, and often occur in patients other airborne allergens also allergic asthma.
The higher incidence of fungal allergy in children in the younger age may be related to the widespread presence of fungi in the air (especially indoor air with poor circulation), and there is a high antigenic crossover between various fungi. Therefore, there is always a chance of fungal sensitization from the newborn, and because the indoor activities of infants and young children are more, the chance of sensitization is greater than that of pollen. Once with age, the sensitivity to fungi declines rapidly, which may explain the world in part. There are large differences in the incidence of fungal allergies in different places. Immunological memory cells can produce specific antibodies against fungi such as secretory immunoglobulin A (sIgA) in the airway, which makes the body's sensitivity to fungi decline rapidly, and fungal spores in the airway. The timely removal of these antigens reduces the exposure of these antigens to bronchial-associated lymphoid tissues, which reduces the immune response.
Prevention
Fungal allergic asthma prevention
1. Try to keep the air in the living room or working environment dry, clean, sunny and well ventilated. If necessary, air filters can be applied to keep the air in the state of circulating filtration. The commonly used filtration method is high-efficiency particle air filtration system. (High-efficiency partculate air filter system, HEPE), is a microporous mechanical filtration device, using activated carbon microporous membrane to remove more than 99.77% of particles suspended in air above 2m (the diameter of fungal spores in air is mostly 2m) Above), the activated carbon filter not only can filter fungal spores and particles, but also absorb the fungal mold molecules in the air, and the other is an electrostatic adsorption filtration method, which uses electrostatic generating devices to electrostatically adsorb particles suspended in the air.
2. The room furnishings of patients with fungal allergic asthma should be as simple as possible. The walls and floors should be tiled. The bedroom should be upstairs. The bed should be placed on a high bed frame. It is not advisable to stack debris under the bed.
3. Patients with severe allergies should be considered for easy treatment. Those who have been confirmed to be occupational fungal allergies should be removed from the work environment as soon as possible.
4. Patients with fungal allergic asthma should avoid dark and humid environments such as mantle, granaries, swamps and firewood where they are piled up or mildewed.
5. Try to avoid the intake of fermented food and edible fungi.
Complication
Fungal allergic asthma complications Complications Pneumothorax mediastinal emphysema atelectasis
Severe episodes can be complicated by pneumothorax, mediastinal emphysema, atelectasis, and advanced pulmonary heart disease.
Symptom
Fungal allergic asthma symptoms Common symptoms Fatigue, asthma, chest tightness, irritability, chills, difficulty breathing, itchy cold sweat
1. Clinical symptoms of fungal allergic asthma
Fungal allergic asthma is a common type of bronchial asthma, mainly due to a wide range of airway hyperresponsiveness and airway allergic inflammation caused by inhalation or ingestion of fungal allergens in patients with atopic dysfunction. Reversible airway obstruction syndrome, because the invasion of this fungus is non-infectious, the fungus stays in the airway for a short time and can be swallowed by macrophages in the airway, so the symptoms are often transient and reversible However, it can trigger a series of immune responses such as airway allergic inflammation in late-onset asthmatic reactions.
The onset of fungal asthma has a certain seasonality, but it is not as obvious as pollen allergic asthma. Patients usually develop sudden onset after exposure to fungal allergens. The prodromal symptoms may include nasal itching, sneezing, clearing, coughing, chest tightness, etc. If not treated in time, asthma attacks may occur due to increased bronchial obstruction. When the asthma is mildly attacked, the patient is conscious, can be supine, has no cyanosis, and is slightly restricted in activity; during moderate episodes, the patient may be short of activity. Can not be supine, often assisted breathing, increased respiratory rate, may have mild cyanosis; severe attack, the patient is forced to seat, both hands front shrug, forehead cold sweat or sweating, cyanosis, asthma frequency and The duration is very different. When accompanied by respiratory infections, cough is often a prominent symptom, cough or phlegm, sometimes accompanied by elevated body temperature. Some patients may present with chronic paroxysmal cough, no typical asthma attack, currently called It is cough variant asthma.
Patients with asthma remission or atypical asthma may have no obvious signs. At the time of onset, the thorax is full and inhaled. The percussion is over-voiced, the heart sounds are narrowed, and the exhalation can be heard and wheezing. If asthma attacks Severe, breathing difficulties are intensified, and wheezing sounds are reduced. Sudden asthma attacks last for more than 24 hours and are called persistent asthma. Patients are extremely dyspnea, irritability, excessive sweating, cyanosis, and can develop blood pressure, unconsciousness or coma. Respiratory failure, long-term recurrent attacks and infections can be complicated by chronic bronchitis, emphysema, etc., severe episodes can be complicated by pneumothorax, mediastinal emphysema, atelectasis, and advanced pulmonary heart disease.
2. Other fungal allergic respiratory diseases
In addition to allergic asthma, fungi can also induce fungal bronchopulmonary allergic diseases of other lung parenchyma, such as fungal-induced allergic pneumonia (also known as fungal exogenous allergic alveolitis). This is a group of non-IgE-mediated fungal allergic reactions in the lungs. Its pathogenesis, pathophysiology and clinical processes are significantly different from those of bronchial asthma. As a asthma control worker, this disease should also be Understand to facilitate differential diagnosis and treatment in clinical work.
These patients often become ill due to inhalation of various fungal spores in living or occupational environments. Some non-fungal inorganic or organic dusts, chemical or pharmaceutical particles can also cause disease after inhalation, but fungi are the main pathogen.
These diseases can be divided into two categories in clinical, one is rapid-onset, called acute allergic pneumonia, and the symptoms are chills, fever, cough, cough, wheezing within 4 to 8 hours after inhalation of large amounts of sensitizing fungi. , fatigue, headache, wet voice at the bottom of the lungs, increased peripheral white blood cells, etc., severe cases may have lung tissue invasive lesions, pulmonary function may have inadequate ventilation function, the second type is occult, also known as subacute or chronic allergic Pneumonia is caused by long-term inhalation of certain fungal spores. Symptoms do not appear in a short period of time. Coughing, shortness of breath, fatigue, weight loss, obvious wheezing after activity, wetness of the lungs, buttocks, chest X-ray There is an increase in lung texture, extensive pulmonary fibrosis in the late stage, inadequate pulmonary function, limited irreversible lung disease, and poor prognosis.
Examine
Fungal allergic asthma test
1. Radiation allergen adsorption test (RAST)
The fungal allergen is adsorbed on the solid support and added to the patient's serum. If the patient's serum contains a specific IgE antibody to the fungus, the two phases cannot be eluted, and the isotopically labeled horse anti-human IgE is added. In serum, the three are combined into a radioactive complex, and the specific amount of radiation can be measured on the gamma counter. The amount of radiation is proportional to the amount of patient-specific IgE, which can be used to determine whether the patient is allergic to fungi. The extent of its allergy.
2. Enzyme-linked allergen adsorption test (ELISA)
The principle is that the fungal allergen is first adsorbed on the pores of the polystyrene plastic plate, and then the serum of the patient to be tested is added, and then the goat anti-human enzyme IgE antibody is added, and then the substrate of the enzyme is added to stop the reaction, and the reaction is used. Color reaction, the OD value was determined on an enzyme-labeled colorimeter to determine the sensitivity and sensitivity of the patient to the fungus.
3. Basophilic granulocyte degranulation test
The patient's venous blood was taken. After anticoagulation treatment, basophils were extracted by centrifugation. The patient's basophils were transferred into two tubes, and the fungal allergen and blank allergen solvent were added respectively. After incubation at 37 ° C for 30 min. , stained with Alcian blue, the number of basophils counted separately under a hemocytometer, if the basophils sampled with the fungal allergen were less than the co-implanted with the blank allergen solvent More than 30% of the samples indicate that more than 30% of the basophil granules are not detected under the microscope due to the specific antigen-antibody reaction, which is a positive reaction. The higher the percentage of degranulation, the more severe the allergic degree.
4. Histamine release test
The principle of this test is to measure the amount of histamine released by the patient's blood cells after interacting with the fungal allergen. The higher the sensitivity of the patient to the fungus, the higher the amount of histamine released, thereby determining the patient's fungus. The degree of sensitization.
5. Fungal culture
Agar diffusion test of fungal antigen antibody, which can specifically diagnose patients with fungal allergic pneumonia, alveolitis or allergic bronchopulmonary aspergillosis, generally using agar double diffusion method to modulate patient serum with different concentrations of fungi The original diffusion test was carried out to observe the appearance of the sedimentation line. This method has obtained positive results for antigens such as Aspergillus fumigatus and Penicillium, and is a good objective basis for identifying pathogenic bacteria.
6. Direct smear examination of fungi from patients with sputum or bronchial secretions
Pick a small sticky gray-brown part from the fresh cough that is coughed up from the patient, spread it thinly on the slide, and wait for the dryness, that is, 1 drop of 0.05% lactic acid cotton blue, and examine it under the microscope after 5 minutes. Blue-stained fungal spores or mycelia, if tested multiple times, can be used as a reference for the diagnosis of fungal allergy.
7. Antigen intradermal test
This is the most widely used routine test in the specific diagnosis of fungal allergic asthma. It is usually used with 1:100 fungal antigen infusion solution, using a 1ml syringe with a 4th injection needle, gently in the outer side of the patient's upper arm. The skin reaction was observed by injecting 0.01 to 0.02 ml for 15 to 20 minutes. In addition to the rapid-phase reaction, the fungal allergen skin test often showed a delayed phase reaction, which should be noted.
8. Bronchial provocation test
The results are accurate and reliable. Because the fungal allergen preparation can be used as an inhalation challenge test to induce symptoms, it should be carried out under close observation. Because of the frequent occurrence of delayed phase reaction, asthma reaction can reappear within 6 to 24 hours after the test. Note that the detailed test method can be found in the chapter on airway reactivity determination.
9. Pulmonary function test
In some asthma patients during clinical remission, there may be closed volume (CV) / vital capacity (VC)%, closed volume (CC) / TLC%, medium-term flow rate (MMEF) and Vma × 50% abnormalities, during asthma attacks, Then all the indicators related to the expiratory flow rate decreased significantly, such as forced expiratory volume in 1 second (FEV1), FEVl/forced vital capacity (FVC)%, MMEF decreased, due to gas blockage and excessive expansion of alveoli, the residual amount of gas ( RV), the functional residual capacity (FRC) and RV/TCL ratio increase. When inhaling 1% isoproterenol or 0.2% salbutamol atomized solution, the above indicators can be improved. If FEV1 is increased by more than 15%, there is Helps diagnosis of bronchial asthma, moderate or severe asthma, uneven distribution of inhaled gas in the lungs, imbalance of ventilation/blood flow ratio, increased physiological dead space and physiological static-arterial shunt, resulting in lower PaO2, but normal or slightly lower PaCO2 When severe asthma or asthma persists, PaO2 is further reduced. Due to respiratory muscle fatigue, PaCO2 may increase, and respiratory acidosis may occur, indicating a serious condition.
10. Airway reactivity determination
Inhalation of histamine, methacholine, sulfur dioxide, prostaglandin F2, taking beta blockers, exercise load, etc., can induce asthma, can be measured by measuring FEVl, maximum expiratory flow rate, airway resistance, etc. Immediately and immediately after every 15 to 30 minutes, the general use of methacholine, because of its fast response, short duration of action, starting from 0.05mg / L, gradually increasing, after inhalation FEV1 reduced by more than 20%, or The airway conductivity drops by more than 35%, which is called the threshold of the drug. The sensitivity of asthmatic patients to inhaled methacholine to cause airway spasm is 100 to 1000 times higher than that of normal people. The slope of the dose-response curve is called reaction. Sexually, asthma patients have increased responsiveness, smokers are also higher than non-smokers, and induced airway obstruction can disappear naturally after 15 to 30 minutes, but patients in the attack period can cause severe asthma and even suffocation, so it is necessary to strictly control Indications, and prepare bronchodilators, anti-shock drugs and other rescue measures, in recent years using airway response tester, continuously record airway resistance, when it rises 2 times, or continuously increases 2 minutes of drugs As the sensitivity index, the airway resistance when inhaling saline is called the initial resistance; the minimum cumulative amount of inhaled drug when the airway resistance is rising is called the reaction threshold; the airway resistance of the cumulative amount of methacholine The rising value is called the resistance rise degree; 1 mg of drug per ml is taken for 1 min for 1 unit, the response threshold is lower than 3 units for sensitivity increase, the average value of asthma patients is 1.08 units; the resistance rise is greater than 0.5 per unit per second. The sensitivity of hmH20/L is increased, so the sensitivity and responsiveness of asthma patients are increased. The airway responsiveness measurement is valuable for the diagnosis of occult asthma, and the diagnosis can be made when the patient is breathing calmly.
Diagnosis
Diagnosis and diagnosis of fungal allergic asthma
diagnosis
1. History collection
The collection of medical history of patients with fungal allergic asthma is very important, not only for the diagnosis of asthma, but also for the search for sensitizing fungi. Therefore, in addition to the items in the general medical history collection, patients should be asked especially for the onset and occupation. Personal and family history of allergies is also a valuable reference for relationships with the work environment, suspicious predisposing factors, prodromal symptoms, course of disease, and previous onset and diagnosis.
2. Clinical examination
Typical bronchial asthma manifests as extensive bronchial lesions. At the time of onset, the patient has expiratory dyspnea, the lungs can smell and exhaled wheezing, the longer the course can form a barrel chest, and the infant can have chicken thoracic deformity. Early patients may have no signs during the remission period.
3. In vivo test of fungal antigen
(1) Skin test: This is the most widely used routine test in the specific diagnosis of fungal allergic asthma. It is usually used with 1:100 fungal antigen infusion solution, using a 1ml syringe, with a 4th injection needle, in the patient. The skin of the outer side of the upper arm was gently injected with 0.01-0.02 ml, and the skin reaction was observed for 15-20 min. In addition to the rapid-phase reaction, the fungal allergen skin test often showed a delayed phase reaction, which should be noted.
(2) Bronchial provocation test: The results are accurate and reliable. The symptoms can be induced by using the fungal allergen preparation as an inhalation challenge test. It should be carried out under close observation, because the delayed phase reaction often occurs within 6-24 hours after the test. An asthma reaction can occur again and should be noted.
4. In vitro diagnosis of fungal allergy
(1) Radiation allergen adsorption test (RAST): The fungal allergen is adsorbed on a solid support and added to the patient's serum. If the patient's serum contains specific IgE antibodies to the fungus, the two phases cannot be combined. When the isotopically labeled horse anti-human IgE serum is added, the three are combined into a radioactive complex, and the specific amount of radiation can be measured on the gamma counter. The amount of radiation and the amount of patient-specific IgE are In proportion, it can be judged whether the patient is allergic to the fungus and allergic to it.
(2) Enzyme-linked allergen adsorption test (ELISA): The principle is that the fungal allergen is first adsorbed on the pores of the polystyrene plastic plate, then the serum of the patient to be tested is added, and then the goat anti-human enzyme labeled IgE antibody is added. The substrate of the enzyme is further added, the reaction is stopped, and the OD value is measured on the enzyme-labeled colorimeter by using the color reaction to determine the sensitivity and sensitivity of the patient to the fungus.
(3) basophil degranulation test: taking venous blood from patients, after anticoagulation treatment, extracting basophils by centrifugation, moving patient basophils into two tubes, adding fungal allergens and blanks respectively. The allergen solvent was incubated at 37 ° C for 30 min, stained with Alcian blue, and the number of basophils was counted under a hemocytometer, respectively. If the sample was co-incubated with the fungal allergen, the basophils were counted. Less than 30% of the samples co-incubated with the blank allergen solvent, indicating that more than 30% of basophil granules can not be detected under the microscope due to the specific antigen-antibody reaction, which is a positive reaction, degranulation The higher the percentage, the more severe the allergies are.
(4) Histamine release test: The principle of this test is to measure the amount of histamine released from the blood cells of the patient after being treated with the fungal allergen. The higher the sensitivity of the patient to the fungus, the higher the amount of histamine released. High, thereby determining the degree of sensitization of the patient to the fungus.
(5) Agar diffusion test of fungal antigen antibody: This test can specifically diagnose patients with fungal allergic pneumonia, alveolitis or allergic bronchopulmonary aspergillosis. Generally, agar double diffusion method is used to compare patient serum with different concentrations. The fungal allergen was subjected to a diffusion test to observe the appearance of the sedimentation line. This method has obtained positive results for the antigens such as Aspergillus fumigatus and Penicillium, and is a good objective basis for identifying the pathogenic bacteria of the patient.
(6) Direct smear examination of the fungus or bronchial secretions of the patient: Pick a small sticky gray-brown part from the fresh cough that is coughed up from the patient, and spread it thinly on the slide, not drying. That is, 1 drop of 0.05% lactic acid cotton blue, after 5 minutes, the light blue-stained fungal spore or mycelium was examined under the microscope. If it was tested positively, it could be used as a reference for diagnosing fungal allergy.
For the diagnosis of fungal allergies, in addition to the above-mentioned various in vitro and in vivo tests, the field investigation of the patient's living environment and working environment is also of great significance. In the investigation, attention should be paid to the temperature and humidity of the patient's living or workplace, lighting, and sanitation. The situation, there are no obvious fungal breeding sources indoors and outdoors and nearby, and fungal exposure sampling and exposure dish culture should be carried out on site to estimate the content and type of fungi in the environment.
5. Pulmonary function test
In some asthma patients during clinical remission, there may be closed volume (CV) / vital capacity (VC)%, closed volume (CC) / TLC%, medium-term flow rate (MMEF) and Vma × 50% abnormalities, during asthma attacks,1(FEV1)FEVl/(FVC)%MMEF( RV)(FRC)RV/TCL1%0.2%FEV115%/-Pa02PaC02Pa02PaC02
6.
F2FEVl1530min10.05mg/LFEV120%35%1001000-1530min22min;;;1mg1min131.08;0.5cmH20/L
Differential diagnosis
1.(air conditioner allergic penumonia)
2.(humidifier allergic pneumonitis)
3. (micropolyspora faeni)
4. (basidiospore)
5.
6.() (aspergillus clavatus)
7.(Penicillium caseii)
8. (bacillus subtilis enzymo)
9.(sitophilus granarius)
10. (cryptostroma corticale)
11. (pullularia)
12. (penicillium frequentans)
13.
