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| Author(s): |
Amanda Rodrigues Maia
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Ribeirão Preto. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC) |
| Defense date: | 2019-05-28 |
| Examining board members: |
Luisa Karla de Paula Arruda;
Marcos de Carvalho Borges;
Keity Souza Santos;
Ariana Campos Yang
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| Advisor: | Luisa Karla de Paula Arruda |
| Abstract | |
The prevalence of allergic diseases has increased in recent years, including asthma and atopic dermatitis. Asthma is a chronic disease resulting from airway hyperresponsiveness and variable airflow limitation, reversible spontaneously or with treatment. The high prevalence, mortality, and associated costs make the disease an important public health problem which requires attention. Atopic dermatitis (AD) is a chronic inflammatory skin disease, as asthma has high prevalence, and it is characterized by intense itching, erythema, excoriations, lichenification in the skin among other characteristics. The AD causes profound impact on individual and family´s life and usually shows the first symptoms during childhood. Both diseases could be related and associated with sensitization to allergens. In the case of asthma, allergy to cockroach is well known to be related with the disease. In 1999, a Brazilian study in our group has shown that among patients with allergic rhinitis and /or asthma the tropomyosin of the American cockroach Periplaneta americana (Per a 7) is a major allergen. This protein is present in vertebrates and invertebrates, and was related to induction of IgE response and cross-reactivity against among invertebrates, including mites, cockroaches, shrimp and parasites. In the present study, we produced recombinant tropomyosin from cockroach (Per a 7 allergen) with high purity and minimal amounts of endotoxin. In an experimental model of asthma in mice, with sensitization and triggering with recombinant Per a 7, there was an increase in the number of total cells, and eosinophils, neutrophils and lymphocytes in the bronchoalveolar lavage. Per a 7 allergen was also used in chimeric ELISA to investigate IgE response to this allergen in 112 patients with atopic dermatitis. Patients\' ages ranged from 3 to 67 years, mean of 24.9 (± 15.4) years, 75 female subjects (67%). In the 112 patients, a mean of SCORAD presented 43.1 (± 18.1) and asthma and rhinitis were reported in 42 and 85 individuals, respectively. Total IgE levels varied from 14.2 to 63.000 IU / mL, with a geometric mean of 2,193 IU / mL. The age at onset of symptoms and disease time presented averages, respectively, of 9.5 (± 12.9) and 15.4 (± 12.3) years. Thirty patients (26.8%) had detectable IgE recombinant Per a 7 levels, ranging from 2.3 to 3191 IU / mL. The ratio of IgA specific for Per a7 / total IgE in these patients ranged from 0.03% to 33.8%. Dividing the patients into sensitized and not sensitized to the cockroach allergen, we observed that there was no significant difference between the groups regarding the age of onset of symptoms, disease time, SCORAD, presence of rhinitis or asthma, and total IgE levels. Our results showed that recombinant Per a 7 allergen induced an inflammatory response with characteristics similar to that observed in humans in an experimental model of asthma in mice. Minor frequency reactivity of IgE Per a 7 allergen was observed among patients with atopic dermatitis in our group, when compared to that previously observed in patients with asthma and / or rhinitis. There was no association between the presence of IgE sensitization to the Per 7 allergen and the severity of atopic dermatitis, presence of asthma or rhinitis, age at onset and disease time, and total IgE levels. However, the investigation of the IgE sensitization profile is important when considering the use of allergen-specific immunotherapy in patients with atopic dermatitis (AU) | |
| FAPESP's process: | 18/02930-9 - Sublingual immunotherapy with tropomyosin in an experimental model of bronchial hyperresponsiveness |
| Grantee: | Amanda Rodrigues Maia |
| Support Opportunities: | Scholarships in Brazil - Master |