Immunomodulatory effect of different extracts from Angiostrongylus cantonensis on airway inflammation in an allergic asthma model.

This study aimed to evaluate the effects of early-life exposure to different extracts of Angiostrongylus cantonensis (A. cantonensis) on airway inflammation in an allergic asthma model. The total soluble extract (TE) and the soluble extracts of the digestive (AcD), reproductive (AcR), and cuticle (AcC) systems of A. cantonensis were used for immunisation before ovalbumin (OVA)-sensitisation/challenge in an OVA-induced allergic asthma model. The initial hypothesis of the study was that some soluble extract of the systems (AcD, AcR, or AcC) could be more potent to the modulation of inflammation than the TE. Our data, however, shows that immunisation with the TE is more promising because it decreased the high influx of inflammatory cells on airways and promoted an increase of interferon-γ (IFN-ɣ) and interleukin-10 (IL-10) levels. Besides this, the immunisation with the TE also led to a reduction of goblet cells and mucus overproduction in the lung tissue of asthmatic mice. We believe that the extracts have a distinct capacity to modulate the immune system, due to the TE possessing a greater variability of molecules, which together leads to control of airway inflammation. In conclusion, this is the first study to reveal that the TE of A. cantonensis adult worms has a greater potential for developing a novel therapeutic for allergic asthma.

PEDIATRIC ASTHMA: IMPACT OF THE DISEASE IN CHILDREN RECEIVING OUTPATIENT TREATMENT IN SOUTHERN BRAZIL.

OBJECTIVE: To evaluate the impact of pediatric asthma on patients of a specialized outpatient clinic in Southern Brazil. METHODS: The study included children aged 8 to 17 years old with asthma diagnosis (mild, moderate and severe) under treatment at the asthma clinic of Hospital São Lucas da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazil. Measurements of spirometry, quality of life, disease control and atopy tests were applied. RESULTS: A total of 66 children were included in the study and divided into groups, according to the severity of the disease: mild, moderate or severe asthma. The results showed similarities in both the treatment and the impact of asthma between groups, except for adherence to treatment: the group with mild asthma showed least adherence to treatment, and the group with severe asthma, greater adherence (p=0.011). As to school absenteeism, the group with severe asthma showed higher frequency (p=0.012), with over 10 days per year (p=0.043). Spirometry showed lower volume/capacity for the group with moderate asthma, followed by the groups with severe and mild asthma. All groups had a high prevalence of allergic asthma, with mites as the main allergens. For quality of life (QOL), and health-related quality of life (HRQOL) levels, there were no differences between groups. In addition, the values were close to the acceptable levels for the total score and for each one of the six domains. The same occurred for the HRQOL-asthma module. CONCLUSIONS: QOL and HRQOL present acceptable levels regardless of the severity of the disease.

Pediatric asthma: impact of the disease in children receiving outpatient treatment in southern brazil / Asma pediátrica: impacto da doença em crianças em acompanhamento ambulatorial no sul do brasil

ABSTRACT Objective: To evaluate the impact of pediatric asthma on patients of a specialized outpatient clinic in Southern Brazil. Methods: The study included children aged 8 to 17 years old with asthma diagnosis (mild, moderate and severe) under treatment at the asthma clinic of Hospital São Lucas da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazil. Measurements of spirometry, quality of life, disease control and atopy tests were applied. Results: A total of 66 children were included in the study and divided into groups, according to the severity of the disease: mild, moderate or severe asthma. The results showed similarities in both the treatment and the impact of asthma between groups, except for adherence to treatment: the group with mild asthma showed least adherence to treatment, and the group with severe asthma, greater adherence (p=0.011). As to school absenteeism, the group with severe asthma showed higher frequency (p=0.012), with over 10 days per year (p=0.043). Spirometry showed lower volume/capacity for the group with moderate asthma, followed by the groups with severe and mild asthma. All groups had a high prevalence of allergic asthma, with mites as the main allergens. For quality of life (QOL), and health-related quality of life (HRQOL) levels, there were no differences between groups. In addition, the values were close to the acceptable levels for the total score and for each one of the six domains. The same occurred for the HRQOL-asthma module. Conclusions: QOL and HRQOL present acceptable levels regardless of the severity of the disease.

RESUMO Objetivo: Avaliar o impacto da asma pediátrica de pacientes em acompanhamento ambulatorial em um centro de referência em pneumopediatria do Sul do Brasil. Métodos: Participaram do estudo crianças com idade entre oito e 17 anos, com diagnóstico de asma (leve, moderada e grave), em acompanhamento no ambulatório de asma do Hospital São Lucas da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS). Foram verificadas medidas de espirometria, avaliação dos níveis de qualidade de vida, controle da doença e teste de atopia. Resultados: Sessenta e seis crianças participaram do estudo, divididas em três grupos (asma leve, moderada e grave). Evidenciaram-se semelhanças tanto no tratamento quanto no impacto da asma, exceto para a adesão ao tratamento (p=0,011), em que o grupo de asma leve é o que menos adere e o grupo de asma grave o que mais adere ao tratamento. Em relação ao absenteísmo escolar, o grupo de asma grave apresentou o maior valor (p=0,012), com mais de dez dias/ano (p=0,043). As espirometrias demonstram menor volume/capacidade para o grupo de asma moderada, seguido do grupo de asma grave e asma leve. Os grupos possuem alta prevalência de asma alérgica, tendo os ácaros como os principais alérgenos. Quanto à qualidade de vida (QV) e à qualidade de vida relacionada à saúde (QVRS), não houve diferença entre os grupos. Além disso, os valores apresentados estão próximos aos níveis aceitáveis, tanto para o escore total quanto para os seis domínios analisados. O mesmo ocorre para o módulo QVRS-asma. Conclusões: Os níveis de QV e de QVRS demonstram-se aceitáveis, independentemente da gravidade da doença.

Fructose-1,6-Bisphosphate Prevents Bleomycin-Induced Pulmonary Fibrosis in Mice and Inhibits the Proliferation of Lung Fibroblasts.

Pulmonary fibrosis is a specific form of interstitial pneumonia. In addition to the idiopathic cause, it may be caused by drugs such as bleomycin (BLM)-used in the treatment of tumors. Fructose-1,6-bisphosphate (FBP) is a high-energy endogenous glycolytic compound that has antifibrotic, anti-inflammatory, and immunomodulatory effects. The aim of this study was to investigate the effects of FBP on both BLM-induced pulmonary fibrosis in mice and in a human embryonic lung fibroblast (MRC-5) culture system. C57BL/6 mice were divided into four groups: control, FBP, BLM, and BLM plus FBP. A single dose of bleomycin (7.5 U/kg) was administered intratracheally, and survival, body weight, Ashcroft score, and histological analysis were evaluated. Pulmonary function and bronchoalveolar lavage fluid (BALF) were also evaluated after a single dose of bleomycin (1.2 U/kg-intratracheally). Treatment with FBP (500 mg/kg) was given on day 0 intraperitoneally. Fibroblasts (MRC-5 cells) were used to access the effect of FBP in vitro. In vivo, FBP increased the survival rate and reduced body weight loss (BLM vs. BLM plus FBP-p < 0.05). FBP also prevented BLM-induced loss of pulmonary function and decreased BALF inflammatory cells, level of fibrosis, and superficial collagen density (p < 0.05). In vitro, FBP (0.62 and 1.25 mM) had inhibitory activity on MRC-5 cells and was able to induce senescence in fibroblasts. These results showed that FBP has the potential of reducing the toxic effects of BLM and may provide supportive therapy for conventional methods used for the treatment of cancer.

Revisão sistemática sobre modelos experimentais de asma aguda e crônica induzidos com extrato de ácaro da poeira doméstica / Systematic review on experimental models of acute and chronic asthma induced with house dust mite extract

Introdução: Asma é uma doença crônica das vias aéreas inferiores com elevada prevalência. Pesquisadores no mundo todo têm desenvolvido vários estudos experimentais em camundongos com o objetivo de entender melhor os mecanismos da doença e testar novas terapias. Ácaros estão presentes de forma abundante na poeira doméstica, sendo considerados os alérgenos mais comuns desencadeantes de asma alérgica. Este estudo objetiva apresentar e discutir desfechos inflamatórios no tecido pulmonar dos camundongos, verificar a diferença entre os modelos agudo e crônico de asma alérgica, tempo de exposição ao alérgeno, dose administrada e seu impacto nas pesquisas em modelos experimentais com asma. Métodos: A revisão da literatura foi realizada em quatro bancos de dados (PubMed, Scielo, Scopus e ScienceDirect). Os artigos selecionados foram avaliados primeiramente por dois pesquisadores de forma independente, de acordo com os critérios de inclusão. Resultados: Foram separados 126 artigos. Aplicados os critérios de inclusão e exclusão, somente 15 foram selecionados. São artigos que apresentaram diferentes protocolos de exposição ao HDM. A dose de HDM mais encontrada foi 100µg seguida por 25µg, e o tipo de modelo foi agudo. Conclusão: No modelo agudo, observa-se um elevado nível de inflamação das vias aéreas. Já o modelo crônico reproduz melhor as características da asma em humanos, hiper-responsividade brônquica e remodelamento das vias aéreas (AU)

Introduction: Asthma is a chronic disease of the lower airways with a high prevalence. Researchers worldwide have developed several experimental studies in mice with the goal of better understanding the mechanisms of the disease and testing new therapies. Mites are abundantly present in household dust, being considered the most common allergens triggering allergic asthma. This study aims to present and discuss inflammatory outcomes in the lung tissue of the mice, verify the difference between acute and chronic models of allergic asthma, time of exposure to the allergen, dose administered and its impact on research in experimental models with asthma. Methods: Literature review was performed in four databases (PubMed, Scielo, Scopus and ScienceDirect). The selected articles were first evaluated by two researchers independently, according to the inclusion criteria. Results: A total of 126 articles were separated. When the inclusion and exclusion criteria were applied, only 15 were selected. They are articles that presented different protocols of exposure to HDM. The most commonly found HDM dose was 100µg followed by 25µg, and the model type was acute. Conclusion: In the acute model, a high level of airway inflammation is observed. However, the chronic model better reproduces the characteristics of asthma in humans, bronchial hyperresponsiveness, and airway remodeling (AU)

Lack of association between viral load and severity of acute bronchiolitis in infants.

OBJECTIVE:: To investigate the correlation between respiratory syncytial viral load and length of hospitalization in infants with acute wheezing episodes. METHODS:: This was a two-year, cross-sectional study of infants ≤ 12 months of age with bronchiolitis at the time of admission to a tertiary hospital. For the identification of respiratory viruses, nasopharyngeal secretions were collected. Samples were analyzed (throughout the study period) by direct immunofluorescence and (in the second year of the study) by quantitative real-time PCR. We screened for three human viruses: rhinovirus, respiratory syncytial virus, and metapneumovirus. RESULTS:: Of 110 samples evaluated by direct immunofluorescence, 56 (50.9%) were positive for a single virus, and 16 (14.5%) were positive for two or more viruses. Among those 72 samples, the most prevalent virus was respiratory syncytial virus, followed by influenza. Of 56 samples evaluated by quantitative real-time PCR, 24 (42.8%) were positive for a single virus, and 1 (1.7%) was positive for two viruses. Among those 25 samples, the most prevalent virus was again respiratory syncytial virus, followed by human rhinovirus. Coinfection did not influence the length of the hospital stay or other outcome s. In addition, there was no association between respiratory syncytial virus load and the length of hospitalization. CONCLUSIONS:: Neither coinfection nor respiratory syncytial viral load appears to influence the outcomes of acute bronchiolitis in infants. OBJETIVO:: Investigar a correlação entre a carga viral do vírus sincicial respiratório e o tempo de internação hospitalar em lactentes com episódios de sibilância aguda. MÉTODOS:: Este foi um estudo transversal de dois anos envolvendo lactentes de até 12 meses de idade com bronquiolite no momento da internação em um hospital terciário. Para a identificação dos vírus respiratórios foram coletadas secreções nasofaríngeas. As amostras foram analisadas (por todo o período do estudo) por imunofluorescência direta e (no segundo ano do estudo) por PCR quantitativa em tempo real para três vírus humanos (rinovírus, vírus sincicial respiratório e metapneumovírus). RESULTADOS:: Das 110 amostras avaliadas por imunofluorescência direta, 56 (50,9%) foram positivas para um único vírus, e 16 (14,5%) foram positivas para dois ou mais vírus. Nessas 72 amostras, o vírus mais prevalente foi o vírus sincicial respiratório, seguido por influenza. Das 56 amostras avaliadas por PCR quantitativa em tempo real, 24 (42,8%) foram positivas para um único vírus, e 1 (1,7%) foi positiva para dois vírus. Nessas 25 amostras, o vírus mais prevalente foi o vírus sincicial respiratório, seguido por rinovírus humano. A coinfecção não influenciou o tempo de internação ou outros desfechos. Além disso, não houve associação entre a carga viral de vírus sincicial respiratório e o tempo de internação. CONCLUSÕES:: A coinfecção e a carga viral do vírus sincicial respiratório não parecem influenciar os desfechos em lactentes com bronquiolite aguda.

Protective effect of early prenatal stress on the induction of asthma in adult mice: Sex-specific differences.

Adversities faced during the prenatal period can be related to the onset of diseases in adulthood. However, little is known about the effects on the respiratory system. This study aimed to evaluate the effects of prenatal stress in two different time-points during pregnancy on pulmonary function and on the inflammatory profile of mice exposed to an asthma model. Male and female BALB/c mice were divided into 3 groups: control (CON), prenatal stress from the second week of pregnancy (PNS1) and prenatal stress on the last week of pregnancy (PNS2). Both PNS1 and PNS2 pregnant females were submitted to restraint stress. As adults, fear/anxiety behaviors were assessed, and animals were subjected to an asthma model induced by ovalbumin. Pulmonary function, inflammatory parameters in bronchoalveolar lavage (BAL) and histology were evaluated. There was a significant decrease in the number of entries and time spent in the central quadrant on the open field test for the PNS1 animals. Females (PNS1) showed improved pulmonary function (airway resistance, tissue damping and pulmonary elastance), significant increase in the percentage of neutrophils and lymphocytes and a decrease in eosinophils when compared to controls. There was a significant decrease in inflammatory cytokines in BAL of both males (IL-5 and IL-13) and females (IL-4, IL-5 and IL-13) from PNS1 and PNS2 when compared to the CON group. Prenatal stress starting from the beginning of pregnancy reduces the impact of asthma development in adult female mice, showing an improved pulmonary function and a lower inflammatory response in the lungs.

Lack of association between viral load and severity of acute bronchiolitis in infants / Falta de associação entre carga viral e gravidade da bronquiolite aguda em lactentes

ABSTRACT Objective: To investigate the correlation between respiratory syncytial viral load and length of hospitalization in infants with acute wheezing episodes. Methods: This was a two-year, cross-sectional study of infants ≤ 12 months of age with bronchiolitis at the time of admission to a tertiary hospital. For the identification of respiratory viruses, nasopharyngeal secretions were collected. Samples were analyzed (throughout the study period) by direct immunofluorescence and (in the second year of the study) by quantitative real-time PCR. We screened for three human viruses: rhinovirus, respiratory syncytial virus, and metapneumovirus. Results: Of 110 samples evaluated by direct immunofluorescence, 56 (50.9%) were positive for a single virus, and 16 (14.5%) were positive for two or more viruses. Among those 72 samples, the most prevalent virus was respiratory syncytial virus, followed by influenza. Of 56 samples evaluated by quantitative real-time PCR, 24 (42.8%) were positive for a single virus, and 1 (1.7%) was positive for two viruses. Among those 25 samples, the most prevalent virus was again respiratory syncytial virus, followed by human rhinovirus. Coinfection did not influence the length of the hospital stay or other outcome s. In addition, there was no association between respiratory syncytial virus load and the length of hospitalization. Conclusions: Neither coinfection nor respiratory syncytial viral load appears to influence the outcomes of acute bronchiolitis in infants.

RESUMO Objetivo: Investigar a correlação entre a carga viral do vírus sincicial respiratório e o tempo de internação hospitalar em lactentes com episódios de sibilância aguda. Métodos: Este foi um estudo transversal de dois anos envolvendo lactentes de até 12 meses de idade com bronquiolite no momento da internação em um hospital terciário. Para a identificação dos vírus respiratórios foram coletadas secreções nasofaríngeas. As amostras foram analisadas (por todo o período do estudo) por imunofluorescência direta e (no segundo ano do estudo) por PCR quantitativa em tempo real para três vírus humanos (rinovírus, vírus sincicial respiratório e metapneumovírus). Resultados: Das 110 amostras avaliadas por imunofluorescência direta, 56 (50,9%) foram positivas para um único vírus, e 16 (14,5%) foram positivas para dois ou mais vírus. Nessas 72 amostras, o vírus mais prevalente foi o vírus sincicial respiratório, seguido por influenza. Das 56 amostras avaliadas por PCR quantitativa em tempo real, 24 (42,8%) foram positivas para um único vírus, e 1 (1,7%) foi positiva para dois vírus. Nessas 25 amostras, o vírus mais prevalente foi o vírus sincicial respiratório, seguido por rinovírus humano. A coinfecção não influenciou o tempo de internação ou outros desfechos. Além disso, não houve associação entre a carga viral de vírus sincicial respiratório e o tempo de internação. Conclusões: A coinfecção e a carga viral do vírus sincicial respiratório não parecem influenciar os desfechos em lactentes com bronquiolite aguda.

Recombinant human deoxyribonuclease therapy improves airway resistance and reduces DNA extracellular traps in a murine acute asthma model.

PURPOSE: Asthma is a highly prevalent chronic inflammatory lung disease characterized by airway hyperresponsiveness to allergens, airway edema, and increased mucus secretion. Such mucus can be liquefied by recombinant human deoxyribonuclease (rhDNase), in which efficacy of rhDNase has been well documented in patients with cystic fibrosis, but little studied in asthma. In the present study, we investigated whether rhDNase intranasal administration improved inflammation and pulmonary function in an experimental model of asthma. METHODS: Mice were sensitized by two subcutaneous injections of ovalbumin (OVA), on days 0 and 7, followed by three intranasal challenges with OVA on days 14, 15, and 16. A control group, replacing OVA by DPBS, was included. On days 15 and 16, after 2 hours of OVA challenge, mice received 1 mg/mL of intranasal rhDNase. RESULTS: We showed that rhDNase decreased significantly the airway resistance and reduced EETs formation and globet cells hyperplasia. CONCLUSIONS: Our results suggest that extracellular DNA in mucus play a role in lower airways obstruction in OVA asthma protocol and that the treatment with rhDNase improved lung function and DNA extracellular traps, with no direct cellular anti-inflammatory effects.

Acute and chronic exposure to Tyrophagus putrescentiae induces allergic pulmonary response in a murine model.

BACKGROUND: Tyrophagus putrescentiae (Tp) is a source of aeroallergen that causes allergic diseases. OBJECTIVE: To describe an acute and chronic murine model of allergic asthma with Tp extract with no systemic sensitization and no use of adjuvant. METHODS: Mites from dust sample were cultured and a raw extract was produced. Female BALB/c mice (6-8 weeks) were challenged intranasally with Tp extract or Dulbecco's phosphate-buffered saline, for 10 consecutive days (acute protocol) or for 6 weeks (chronic protocol). Twenty-four hours after the last intranasal challenge, bronchoalveolar lavage fluid (BALF) was performed for total and differential cells count, cytokine analysis, and eosinophil peroxidase activity. Lung tissue was also removed for histopathologic analysis. RESULTS: Tp extract has shown a significant increase in total cells count from BALF as well as an increase in absolute eosinophils count, eosinophil peroxidase activity, interleukin (IL)-5 and IL-13 levels, in both acute and chronic protocols. Peribronchovascular infiltrate, goblet cells hyperplasia and collagen deposition were shown in the airways of acute and chronic Tp-exposed mice. CONCLUSION: Our data suggest that the intranasal exposure to Tp extract, with no systemic sensitization and no use of adjuvants, induces a robust allergic inflammation in the lungs of mice, in both acute and chronic models. Our Tp extract seems to be a potent allergen extract which may be used in asthma model studies.

Recombinant human deoxyribonuclease attenuates oxidative stress in a model of eosinophilic pulmonary response in mice.

The inflammatory cells infiltrating the airways produce several mediators, such as reactive oxygen species (ROS). ROS and the oxidant-antioxidant imbalance might play an important role in the modulation of airways inflammation. In order to avoid the undesirable effects of ROS, various endogenous antioxidant strategies have evolved, incorporating both enzymatic and non-enzymatic mechanisms. Recombinant human deoxyribonuclease (rhDNase) in clinical studies demonstrated a reduction in sputum viscosity, cleaving extracellular DNA in the airways, and facilitating mucus clearance, but an antioxidant effect was not studied so far. Therefore, we evaluated whether the administration of rhDNase improves oxidative stress in a murine model of asthma. Mice were sensitized by two subcutaneous injections of ovalbumin (OVA), on days 0 and 7, followed by three lung challenges with OVA on days 14, 15, and 16. On days 15 and 16, after 2 h of the challenge with OVA, mice received 1 mg/mL of rhDNase in the lungs. Bronchoalveolar lavage fluid and lung tissue were obtained on day 17, for inflammatory and oxidative stress analysis. We showed that rhDNase did not alter the population of inflammatory cells, such as eosinophil cells, in OVA-treated rhDNase group but significantly improved oxidative stress in lung tissue, by decreasing oxygen reactive species and increasing superoxide dismutase/catalase ratio, glutathione peroxidase activity, and thiol content. Our data provide the first evidence that rhDNase decreases some measures of oxidative stress and antioxidant status in a murine model of asthma, with a potential antioxidant effect to be further studied in human asthma.

Clinical characteristics of children and adolescents with severe therapy-resistant asthma in Brazil.

OBJECTIVE: To describe the clinical characteristics, lung function, radiological findings, and the inflammatory cell profile in induced sputum in children and adolescents with severe therapy-resistant asthma (STRA) treated at a referral center in southern Brazil. METHODS: We retrospectively analyzed children and adolescents (3-18 years of age) with uncontrolled STRA treated with high-dose inhaled corticosteroids and long-acting ß2 agonists. We prospectively collected data on disease control, lung function, skin test reactivity to allergens, the inflammatory cell profile in induced sputum, chest CT findings, and esophageal pH monitoring results. RESULTS: We analyzed 21 patients (mean age, 9.2 ± 2.98 years). Of those, 18 (86%) were atopic. Most had uncontrolled asthma and near-normal baseline lung function. In 4 and 7, induced sputum was found to be eosinophilic and neutrophilic, respectively; the inflammatory cell profile in induced sputum having changed in 67% of those in whom induced sputum analysis was repeated. Of the 8 patients receiving treatment with omalizumab (an anti-IgE antibody), 7 (87.5%) showed significant improvement in quality of life, as well as significant reductions in the numbers of exacerbations and hospitalizations. CONCLUSIONS: Children with STRA present with near-normal lung function and a variable airway inflammatory pattern during clinical follow-up, showing a significant clinical response to omalizumab. In children, STRA differs from that seen in adults, further studies being required in order to gain a better understanding of the disease mechanisms.

Clinical characteristics of children and adolescents with severe therapy-resistant asthma in Brazil / Características clínicas de crianças e adolescentes brasileiros com asma grave resistente a terapia

AbstractObjective: To describe the clinical characteristics, lung function, radiological findings, and the inflammatory cell profile in induced sputum in children and adolescents with severe therapy-resistant asthma (STRA) treated at a referral center in southern Brazil.Methods: We retrospectively analyzed children and adolescents (3-18 years of age) with uncontrolled STRA treated with high-dose inhaled corticosteroids and long-acting β2 agonists. We prospectively collected data on disease control, lung function, skin test reactivity to allergens, the inflammatory cell profile in induced sputum, chest CT findings, and esophageal pH monitoring results.Results: We analyzed 21 patients (mean age, 9.2 ± 2.98 years). Of those, 18 (86%) were atopic. Most had uncontrolled asthma and near-normal baseline lung function. In 4 and 7, induced sputum was found to be eosinophilic and neutrophilic, respectively; the inflammatory cell profile in induced sputum having changed in 67% of those in whom induced sputum analysis was repeated. Of the 8 patients receiving treatment with omalizumab (an anti-IgE antibody), 7 (87.5%) showed significant improvement in quality of life, as well as significant reductions in the numbers of exacerbations and hospitalizations.Conclusions: Children with STRA present with near-normal lung function and a variable airway inflammatory pattern during clinical follow-up, showing a significant clinical response to omalizumab. In children, STRA differs from that seen in adults, further studies being required in order to gain a better understanding of the disease mechanisms.

ResumoObjetivo: Descrever as principais características clínicas, a função pulmonar, as características radiológicas e o perfil inflamatório do escarro induzido de crianças e adolescentes com asma grave resistente a terapia (AGRT) tratados em um centro de referência do sul do Brasil.Métodos: Foram analisadas retrospectivamente crianças e adolescentes de 3-18 anos com diagnóstico de AGRT não controlada acompanhados durante pelo menos 6 meses e tratados com doses elevadas de corticoide inalatório associado a um β2-agonista de longa duração. Foram coletados prospectivamente dados relativos ao controle da doença, função pulmonar, teste cutâneo para alérgenos, perfil inflamatório do escarro induzido, TC de tórax e pHmetria esofágica.Resultados: Foram analisados 21 pacientes (média de idade: 9,2 ± 2,98 anos). Dos 21, 18 (86%) eram atópicos. A maioria apresentava asma não controlada e função pulmonar basal próxima do normal. Em 4 e 7 pacientes, o escarro induzido revelou-se eosinofílico e neutrofílico, respectivamente, e 67% dos pacientes que repetiram o exame apresentaram mudança no perfil inflamatório. Dos 8 pacientes que receberam omalizumabe (um anticorpo anti-IgE), 7 (87,5%) apresentaram melhora importante da qualidade de vida, com redução importante das exacerbações e hospitalizações.Conclusões: Crianças com AGRT apresentam função pulmonar próxima do normal e padrão inflamatório das vias aéreas variável durante o seguimento clínico, com importante resposta clínica ao omalizumabe. A AGRT em crianças difere da AGRT em adultos, e são necessários mais estudos para esclarecer os mecanismos da doença.

Proposed short-term model of acute allergic response, without adjuvant use, in the lungs of mice.

OBJECTIVE: To determine whether a short-term protocol using subcutaneous sensitization with ovalbumin, without the use of adjuvants, would induce an eosinophilic response in the lungs of mice similar to that observed in previous, well-established protocols. METHODS: Adult female BALB/c mice were randomized and divided into groups according to the number of sensitizations with ovalbumin and the number/dosage of intranasal ovalbumin challenges. The short-term protocol (10 days) consisted of one sensitization with ovalbumin and three ovalbumin challenges (100 µg). Total and differential cell counts in BAL fluid, levels of eosinophil peroxidase in lung tissue, and histopathological examination of the lungs were performed 24 h after the last ovalbumin challenge. RESULTS: No significant differences were found among the groups regarding the variables studied. The short-term protocol, as well as the other protocols studied, induced an eosinophilic response similar to that obtained in the positive control. CONCLUSIONS: Subcutaneous sensitization with ovalbumin and without the use of adjuvants resulted in a significant allergic response in the lungs of mice, even in the short-term protocol group. Our findings suggest that this short-term protocol can be used as a first-line pre-clinical test for the study of new medications, reducing the costs and observation periods.

Proposta de um modelo murino de curta duração de resposta pulmonar alérgica aguda sem utilização de adjuvante / Proposed short-term model of acute allergic response, without adjuvant use, in the lungs of mice

OBJETIVO: Determinar se um protocolo curto de sensibilização com ovalbumina subcutânea, sem adjuvante, induziria uma resposta pulmonar eosinofílica em pulmões de camundongos similar àquela encontrada em protocolos previamente estabelecidos. MÉTODOS: Fêmeas adultas de camundongos BALB/c foram randomizadas e divididas em grupos de acordo com o número de sensibilizações com ovalbumina e o número/dosagem de provocação intranasal. O protocolo curto (10 dias) consistiu de uma sensibilização e três provocações com ovalbumina (100 µg). A contagem total e diferencial de células no lavado broncoalveolar, o nível de peroxidase eosinofílica no tecido pulmonar e o exame histopatológico dos pulmões foram realizados 24 h após a última provocação. RESULTADOS: Não houve diferenças significativas entre os grupos em relação às variáveis estudadas. O protocolo curto, assim como os outros protocolos estudados, induziu uma resposta eosinofílica pulmonar semelhante àquela do grupo controle positivo. CONCLUSÕES: A sensibilização por ovalbumina subcutânea sem o uso de adjuvante resultou em uma significativa resposta pulmonar alérgica em ratos, mesmo no grupo de protocolo curto. Nossos achados sugerem que esse protocolo curto pode ser utilizado como teste pré-clínico de primeira linha para a pesquisa de novos fármacos, reduzindo custos e o tempo de observação.

OBJECTIVE: To determine whether a short-term protocol using subcutaneous sensitization with ovalbumin, without the use of adjuvants, would induce an eosinophilic response in the lungs of mice similar to that observed in previous, well-established protocols. METHODS: Adult female BALB/c mice were randomized and divided into groups according to the number of sensitizations with ovalbumin and the number/dosage of intranasal ovalbumin challenges. The short-term protocol (10 days) consisted of one sensitization with ovalbumin and three ovalbumin challenges (100 µg). Total and differential cell counts in BAL fluid, levels of eosinophil peroxidase in lung tissue, and histopathological examination of the lungs were performed 24 h after the last ovalbumin challenge. RESULTS: No significant differences were found among the groups regarding the variables studied. The short-term protocol, as well as the other protocols studied, induced an eosinophilic response similar to that obtained in the positive control. CONCLUSIONS: Subcutaneous sensitization with ovalbumin and without the use of adjuvants resulted in a significant allergic response in the lungs of mice, even in the short-term protocol group. Our findings suggest that this short-term protocol can be used as a first-line pre-clinical test for the study of new medications, reducing the costs and observation periods.

Novas alternativas para protocolos com modelos murinos de asma / New alternatives for protocols with murine models of asthma

Objetivos: Testar alternativas de protocolos com modelos animais de asma aguda e crônica que apresentem características mais próximas da doença em humanos, utilizando ovalbumina livre de adjuvante.Métodos: Foram utilizadas fêmeas adultas de camundongos BALB/c, divididas em grupos de acordo com as sensibilizações com ovalbumina. O modelo agudo utilizou duas doses de ovalbumina subcutânea, sem adjuvante, com intervalo de sete dias, com posterior desafio intranasal durante três dias, comparado ao protocolo padrão que utiliza três doses de ovalbumina intraperitoneal, no período de sensibilização. O modelo crônico também utilizou ovalbumina subcutânea livre de adjuvante para sensibilização, com intervalo de 14 dias e posterior desafio intranasal, três vezes por semana, durante oito semanas. Contagem total e diferencial de células no lavado broncoalveolar e análise histológica dos pulmões foram realizadas 24 horas após o último desafio com ovalbumina.Resultados: Nos dois modelos estudados, agudo e crônico, observou-se uma resposta eosinofílica pulmonar semelhante entre os grupos. A contagem de células e a análise histológica do tecido pulmonar não apresentaram diferença significativa entre os grupos estudados.Conclusões: O uso de sensibilização subcutânea em modelo murino com ovalbumina, sem adjuvante (alum), resulta em significativa resposta inflamatória pulmonar alérgica, com predomínio de eosinófilos, podendo ser uma opção futura para experimentos mais próximos ao modelo humano, tanto na fase aguda, como na fase crônica da doença.

Aims: To test alternative protocols using animal models of acute and chronic asthma, with features closer to human disease, using ovalbumin without adjuvant. Methods: Adult female BALB/c mice were used and divided into groups according to sensitization with ovalbumin. The acute model used two doses of ovalbumin subcutaneously without adjuvant, on days 0 and 7, and after intranasal challenge for consecutives three days, compared with a standard protocol using three doses of ovalbumin for sensitization. The chronic model also used ovalbumin subcutaneously for sensitization, adjuvant-free, on days 0 and 14, and after intranasal challenge, for eight consecutive weeks. Total and differential cell counts from bronchoalveolar lavage and histopathology of the lungs were performed 24 hours after the last ovalbumin challenge. Results: In both models of protocols studied, acute and chronic, we have observed similar allergic pulmonary response between the groups. Cell counts and histological analysis of lung tissue showed no significant difference between groups. Conclusions: Use of sensitization in murine model with ovalbumin subcutaneously, with no adjuvant (alum), resulted in an expected allergic pulmonary response, with predominant eosinophils. These protocols may be a future option to animal models of asthma closer to the human disease, both in the acute and chronic patterns.