Objective: To determine the rate at which satisfactory spirometry results are obtained (spirometry success rate) in preschool children. Methods: We analyzed the spirometry results of children ≤ 6 years of age. All tests were conducted between June of 2009 and February of 2010 in the Pulmonary Function Laboratory of the Hospital Infantil Jeser Amarante Faria, located in the city of Joinville, Brazil. The spirometry program employed features an animated incentive (soap bubbles). The procedures were performed by a pediatric pulmonologist, in accordance with the reproducibility and acceptability criteria recommended by the American Thoracic Society. We attempted to achieve an expiratory time of at least 1 s. The following parameters were measured: FVC, FEV0.5, FEV1, and the FEV1/FVC ratio. Results: Our sample comprised 74 children. The spirometry success rate was 82%. Although the performance improved with age, the difference between younger and older children was not significant (p > 0.05). An average of 6.6 attempts/test were needed in order to achieve acceptable, reproducible curves. All 61 successful tests produced satisfactory FEV0.5 and FEV1 values. By calculating Z scores, we found that 21.6% of the children presented with an obstructive pattern. Conclusions: In our sample, the spirometry success rate was high, showing that spirometry is a valid method for assessing pulmonary function in preschool children. The high success rate in our sample might be attributable to the use of an incentive and to the fact that the tests were performed by professionals specializing in pediatrics.

Keywords: Spirometry; Feasibility studies; Respiratory function tests.

Various wheezing phenotypes can be identified based on differences in natural histories, risk factors and responses to treatment. In epidemiologic studies, atopic asthma or virus-induced wheezing can be discriminated by the presence or the absence of sensitization to allergens. Children with asthma have been shown to present lower levels of lung function. Patients with viral respiratory infections evolve from normal lung function to enhanced airway reactivity. The objective of this study was to identify genes and polymorphisms associated with different wheezing phenotypes. Using data obtained from the Genetic Association Database, we systematically reviewed studies on genes and polymorphisms that have been associated with virus-induced wheezing or atopic asthma. The research was carried out in February of 2009. Genes associated with the studied outcomes in more than three studies were included in the analysis. We found that different genes and loci have been associated with virus-induced wheezing or atopic asthma. Virus-induced wheezing has frequently been associated with IL-8 polymorphisms, whereas atopic asthma and atopy have frequently been associated with Th2 cytokine gene (CD14 and IL-13) polymorphisms on chromosome 5. This review provides evidence that different wheezing disorders in childhood can be differently affected by genetic variations, considering their role on airway inflammation and atopy. Future studies of genetic associations should consider the different wheezing phenotypes in infancy. In addition, stratified analyses for atopy can be useful for elucidating the mechanisms of the disease.

Keywords: Genetics; Polymorphism, genetic; Asthma; Interleukins; Respiratory syncytial viruses.

Foreign body aspiration (FBA) into the tracheobronchial tree is a common problem in children, especially in those under three years of age. Preliminary radiological evaluation reveals normal chest X-rays in nearly 30% of such patients. Tomography-generated virtual bronchoscopy (VB) can facilitate the early diagnosis and rapid management of these cases. The definitive treatment is the removal of the foreign body by means of rigid bronchoscopy under general anesthesia. The objective of this study was to describe the use of VB in two patients with suspicion of FBA, as well as to review the literature regarding this topic. The two patients presented with sudden onset of respiratory symptoms and history of cough or choking with foods before these symptoms. Both patients were submitted to VB. In both cases, we detected an endobronchial foreign body, which was then removed by conventional rigid bronchoscopy in one of the cases. Only recently developed, VB is a noninvasive imaging method that has potential for use in detecting foreign bodies in the airways of children. In select cases, VB can indicate the exact location of the foreign body and even preclude the need to submit patients to rigid bronchoscopy in the absence of a foreign body.

Keywords: Bronchoscopy; Pediatrics; Respiratory aspiration.

Objective: Asthma is the most common chronic pulmonary disease, characterized by bronchial inflammation. Some children with asthma have persistent pulmonary function impairment. The prevalence and etiology of this abnormality in children with asthma in developing countries remain unknown. The objective of this study was to estimate the proportion of patients with impaired pulmonary function who were unresponsive to treatment in a group of children and adolescents with asthma, and to describe the phenotypic characteristics of the sample. Methods: Using a standardized questionnaire, we selected outpatients (5-17 years of age) diagnosed with persistent asthma. These patients underwent spirometry and skin prick tests for sensitivity to common aeroallergens. Persistent pulmonary function impairment was defined as an FEV1/FVC ratio < 0.80, even after 10 days of treatment with bronchodilators and oral corticosteroids. We used the atopic index to differentiate between patients with little or no response to the skin prick test and those with a strong response (cut-off point: 4 allergens). Results: We included 96 patients with a mean age of 10.6 years. Of those, 52 (54.1%) were male, and 89 (92.7%) were atopic. Of the 96 patients, 8 (8.3%) had impaired pulmonary function even after the treatment. Among those patients, 8 (100%) were atopic, 7 (87.5%) had moderate or severe asthma, and 7 (87.5%) had a history of hospitalization for acute bronchiolitis. Conclusions: Children and adolescents with moderate or severe asthma can present with impaired pulmonary function and be unresponsive to treatment. This clinical situation has been little studied in developing countries, and its risk factors and etiology will be better understood only through birth cohort studies.

Keywords: Asthma; Respiratory function tests; Allergy and immunology.

Background: Several lung diseases are characterized by a predominantly neutrophilic inflammation. A better understanding of the mechanisms of action of some drugs on the airway inflammation of such diseases may bring advances to the treatment. Objective: To develop a method to induce pulmonary neutrophilic response in mice, without active infection. Methods: Eight adult Swiss mice were used. The study group (n = 4) received an intranasal challenge with 1 x 1012 CFU/ml of Pseudomonas aeruginosa (Psa), frozen to death. The control group (n = 4) received an intranasal challenge with saline solution. Two days after the intranasal challenge, a bronchoalveolar lavage (BAL) was performed with total cell and differential cellularity counts. Results: The total cell count was significantly higher in the group with Psa, as compared to the control group (median of 1.17 x 106 and 0.08 x 106, respectively, p = 0.029). In addition to this, an absolute predominance of neutrophils was found in the differential cellularity of the mice that had received the Psa challenge. Conclusion: The model of inducing a neutrophilic pulmonary disease using frost-dead bacteria was successfully developed. This neutrophilic inflammatory response induction model in Swiss mice lungs may be an important tool for testing the anti-inflammatory effect of some antimicrobial drugs on the inflammation of the lower airways.

Keywords: Animal experimentation. Lung disesases. Inflammation. Neutrophils. Pseudomonas.

In the present report, we describe an unusual presentation of post-infectious bronchiolitis obliterans accompanied by pulmonary hemosiderosis in a nine-year-old boy with persistent respiratory symptoms subsequent to an episode of acute bronchiolitis occurring at the age of seven months. After the episode, the persistent respiratory symptoms worsened significantly, and, by the age of seven, the patient began to have difficulty breathing after minimal exertion. Computed tomography of the chest presented findings consistent with bronchiolitis obliterans. Open lung biopsy revealed numerous hemosiderin-laden macrophages, as well as other findings consistent with bronchiolitis obliterans. Pulmonary hemosiderosis can occasionally be accompanied by bronchiolitis obliterans in children with severe sequelae after an episode of viral infection.

Keywords: Bronchoalveolar lavage; Bronchiolitis obliterans; Hemosiderosis; Case reports [Publication type]

Macrolides are drugs that have antimicrobial effects, especially against intracellular pathogens. Various studies have shown that macrolides might also have anti-inflammatory effects. Macrolides inhibit the production of interleukins and can reduce pulmonary neutrophilic inflammation. Clinical trials have demonstrated beneficial effects of macrolides in various chronic lung diseases. The objective of this study was to review recent data in the medical literature on the anti-inflammatory effects of macrolides in childhood lung diseases by searching the Medline (PubMed) database. We used the following search terms: "macrolide and cystic fibrosis"; "macrolide and asthma"; "macrolide and bronchiolitis obliterans"; and "macrolide and acute bronchiolitis". We selected articles published in international scientific journals between 2001 and 2012. Clinical studies and in vitro evidence have confirmed the anti-inflammatory effect of macrolides in respiratory diseases. Some clinical trials have shown the benefits of the administration of macrolides in patients with cystic fibrosis, although the risk of bacterial resistance should be considered in the analysis of those benefits. Such benefits are controversial in other respiratory diseases, and the routine use of macrolides is not recommended. Further controlled clinical trials are required in order to assess the efficacy of macrolides as anti-inflammatory drugs, so that the benefits in the treatment of each specific clinical condition can be better established.

Keywords: Macrolides; Asthma; Cystic Fibrosis; Bronchiolitis.

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.

Keywords: Bronchiolitis; Coinfection; Viral load; Hospitalization; Respiratory syncytial virus, human.