Allergic bronchopulmonary aspergillosis is a chronic disease of the bronchopulmonary system caused by the defeat of the respiratory tract by aspergillus fungi and characterized by the development of an allergic inflammatory process in the bronchi. Aspergillosis, as a rule, occurs in patients with bronchial asthma, manifested by fever, cough with mucopurulent sputum, chest pain, periodic attacks of suffocation. The diagnosis is established taking into account the data of clinical examination, blood and sputum tests, X-ray examination of the lungs, allergological tests. Treatment is carried out using glucocorticoids and antifungal drugs.
Allergic bronchopulmonary aspergillosis is an infectious and allergic mold mycosis caused by aspergillus fungi (usually Aspergillus fumigatus) and manifested by the development of respiratory tract dysbiosis, allergic inflammation of the bronchial mucosa and subsequent pulmonary fibrosis. The disease occurs mainly in patients with atopic bronchial asthma (90% of all cases of aspergillosis), as well as with cystic fibrosis and in people with weakened immunity.
The disease was first identified and described in the UK in 1952 among patients with bronchial asthma who had a prolonged increase in body temperature. Currently, allergic bronchopulmonary aspergillosis is more common in people aged 20 to 40 years and is diagnosed in 1-2% of patients with bronchial asthma. The defeat of the respiratory tract by aspergillus fungi is particularly dangerous for people with congenital and acquired immunodeficiency.
The causative agent of allergic bronchopulmonary aspergillosis is yeast-like fungi from the genus aspergillus. In total, about 300 representatives of these microorganisms are known, 15 of which can cause the development of infectious and allergic inflammation when they enter the respiratory tract. In the vast majority of cases, mold mycosis in the bronchi occurs when Aspergillus fumigatus penetrates.
Aspergillus is widespread everywhere, fungal spores are in the air both in summer and in winter. Favorite habitats of these microorganisms are moist, swampy terrain, soils with a rich content of organic fertilizers, squares and parks with fallen leaves, residential and non-residential premises with high humidity (bathrooms, bathrooms, basements in old houses), indoor plant land, bird cages, air conditioners.
The main risk factors facilitating the development of allergic bronchopulmonary aspergillosis are hereditary predisposition (the presence of bronchial asthma and other allergic diseases in relatives), prolonged contact with aspergillus (work on the household plot, livestock farms, flour mills), a decrease in the body’s defenses (primary and secondary immunodeficiency, chronic diseases of the bronchopulmonary system, blood diseases, malignant neoplasms, etc.).
Spores of Aspergillus fungi enter the respiratory tract during inhalation, settle on the mucous membrane of the bronchi, germinate and begin their vital activity. In this case, the release of proteolytic enzymes that damage the epithelial cells of the bronchi occurs. The reaction of the immune system to aspergillus antigens causes the formation of allergy mediators, the synthesis of immunoglobulins E, A and G, the development of an inflammatory process of an allergic nature in the bronchi.
Allergic bronchopulmonary aspergillosis in the vast majority of cases develops in patients with atopic bronchial asthma, more often in the autumn-spring period, that is, in cold wet weather. The disease begins acutely, with chills, an increase in temperature to 38-39 degrees, the appearance of chest pain, cough with mucopurulent sputum, hemoptysis. At the same time, the symptoms of bronchial asthma become more pronounced (a feeling of lack of air, repeated attacks of suffocation). There are signs of intoxication of the body: general weakness, drowsiness, pallor of the skin, lack of appetite, weight loss, prolonged retention of subfebrile temperature, etc.
In the chronic course of allergic bronchopulmonary aspergillosis, the manifestations of the disease can be erased – without signs of intoxication, with periodic cough with mucous sputum, in which there may be brownish inclusions, slight shortness of breath during physical exertion, a feeling of lack of air. If aspergillosis occurs against the background of immunodeficiency, symptoms of the underlying disease (acute leukemia, pulmonary tuberculosis, sarcoidosis, obstructive pulmonary disease, malignant neoplasm of a specific localization) will be present in the clinical picture.
The diagnosis of allergic bronchopulmonary aspergillosis is established by an allergist-immunologist and a pulmonologist based on the study of anamnesis, the clinical picture of the disease, laboratory and instrumental studies, allergological samples:
- Conversation and inspection. Anamnesis of the disease may indicate a hereditary burden of allergic diseases, the presence of atopic bronchial asthma in the patient, periodic or prolonged contact with aspergillus in everyday life or in the course of professional activity. During physical examination, approximately half of patients with allergic bronchopulmonary aspergillosis have a dulling of percussion sound in the upper parts of the lungs and listening to moist small-bubbly wheezing during auscultation, as well as signs of a violation of the general condition – shortness of breath, pallor of the skin, sweating, subfebrility or hyperthermia.
- Laboratory diagnostic tests. During laboratory examination, eosinophilia (more than 20%) is detected in peripheral blood, sometimes leukocytosis and increased ESR are noted. Cytological analysis of sputum reveals the predominance of eosinophils, sputum microscopy can detect elements of aspergillus mycelium. Bacteriological examination of sputum makes it possible to identify the culture of Aspergillus fumigatus during the growth of fungi on nutrient media.
- Allergological examination. Skin allergological tests with aspergillus extract are carried out (a typical immediate type reaction is detected). The diagnosis of allergic bronchopulmonary aspergillosis is confirmed by determining the elevated level of total immunoglobulin E and specific IgE and IgG to Aspergillus fumigatus in the blood serum.
- X-ray diagnostics. During bronchography and computed tomography, proximal bronchiectasis, “volatile” infiltrates in the lungs are detected.
Differential diagnosis of allergic bronchopulmonary aspergillosis is carried out with pulmonary tuberculosis, sarcoidosis, chronic obstructive pulmonary disease, eosinophilic pulmonary lesions of other etiology.
Treatment of bronchopulmonary aspergillosis
The main directions of treatment of aspergillosis with damage to the bronchopulmonary system are anti-inflammatory therapy, reducing the sensitization of the body and reducing the activity of aspergillus.
In the acute period of the disease, systemic glucocorticosteroid hormones are prescribed for at least six months (the drug of choice is prednisone). The use of glucocorticosteroids begins in therapeutic dosages and continues until complete resorption of infiltrates and normalization of antibody titers, after which they switch to maintenance for another 4-6 months. After complete relief of the inflammatory process, that is, in remission, antifungal therapy with amphotericin B or traconazole is started for 4-8 weeks.
Prognosis and prevention
The prognosis depends on the frequency and severity of exacerbations of aspergillosis, concomitant background. With frequent exacerbations and the presence of other diseases in the anamnesis, the quality of life significantly suffers. Compliance with the precautionary rules during agricultural work allows you to prevent primary invasion. First of all, this applies to people with bronchial asthma and immunodeficiency. To prevent relapses of allergic bronchopulmonary aspergillosis, it is necessary to ensure maximum reduction of contact with aspergillus, and if possible, moving to a high-altitude area with a dry climate.