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BACKGROUND: Asthmatic children present variable degrees of airway inflammation, remodeling, and resistance, which correlate with disease control and severity. The chronic inflammatory process of the airway triggers airway remodeling, which reflects the degree of airway resistance. Pro-inflammatory and pro-fibrotic mediators are centrally involved in this process. OBJECTIVE: To investigate whether the levels of pulmonary and systemic pro-inflammatory and pro-fibrotic mediators present a correlation with the resistance of the respiratory system and of the proximal and distal airways. METHODS: 39 Asthmatic children (persistent mild and moderate) and 39 non-asthmatic children (both between 6 and 13 years old) were evaluated for anthropometric characteristics, lung function and mechanics, and pulmonary and systemic immune responses. RESULTS: Asthmatic children showed an increased number of blood eosinophils (p < 0.04), basophils (p < 0.04), monocytes (p < 0.002) and lymphocytes (p < 0.03). In addition, asthmatic children showed impaired lung function, as demonstrated by FEV1 (p < 0.0005) and FEV1/FVC (p < 0.004), decreased total resistance of the respiratory system (R5Hz; p < 0.009), increased resistance of the proximal airways (R20Hz; p < 0.02), increased elastance (Z5Hz; p < 0.02) and increased reactance (X5Hz; p < 0.002) compared to non-asthmatic children. Moreover, the following inflammatory factors were significantly higher in asthmatic than non-asthmatic children: GM-CSF in the breath condensate (BC) (p < 0.0001) and in the serum (p < 0.0001); TGF-beta in the BC (p < 0.0001) and in the serum (p < 0.004); IL-5 in the BC (p < 0.02) and in the serum (p < 0.01); IL-4 in the serum (p < 0.0002). CONCLUSIONS: Impulse oscillometry is a sensitive method to detect airway resistance in persistent mild and moderate asthmatic children, an event followed by increased levels of pro-inflammatory and pro-fibrotic mediators.

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BACKGROUND: Both short and long-term exposure to traffic-related air pollutants have been associated with asthma and reduced lung function. We hypothesized that short-term indoor exposure to fine particulate matter <2.5 µm (PM2.5) and vanadium (V) would be associated with altered buccal cell DNA methylation of targeted asthma genes and decreased lung function among urban children in a nested subcohort of African American and Dominican children. METHODS: Six day integrated levels of air pollutants were measured from children's homes (age 9-14; n = 163), repeated 6 months later (n = 98). Buccal samples were collected repeatedly during visits. CpG promoter loci of asthma genes (i.e., interleukin 4 (IL4), interferon gamma (IFNγ), inducible nitric oxide synthase (NOS2A), arginase 2 (ARG2)) were pyrosequenced and lung function was assessed. RESULTS: Exposure to V, but not PM2.5, was associated with lower DNA methylation of IL4 and IFNγ. In exploratory analyses, V levels were associated with lower methylation of the proinflammatory NOS2A-CpG+5099 among asthmatic overweight or obese children but not nonasthmatics. Short-term exposure to PM2.5, but not V, appeared associated with lower lung function (i.e., reduced z-scores for forced expiratory volume in one second (FEV1, FEV1/ forced vital capacity [FEV1/FVC] and forced expiratory flow at 25-75% of FVC [FEF25-75]). CONCLUSIONS: Exposure to V was associated with altered DNA methylation of allergic and proinflammatory asthma genes implicated in air pollution related asthma. However, short-term exposure to PM2.5, but not V, appeared associated with decrements in lung function among urban children.

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Introducción: el humo ambiental del tabaco es un riesgo significativo para la salud de los niños pequeños. Se pretende estudiar el papel del tabaquismo pasivo en el padecimiento de asma en niños. Objetivo: identificar la presencia de tabaquismo pasivo y su asociación con la recurrencia de crisis en niños asmáticos de edad escolar. Métodos: estudio longitudinal de casos y controles (n= 320) en el servicio de Alergología del Hospital Pediátrico Universitario "William Soler" de La Habana, en el período comprendido entre febrero 2014 y enero 2015. Se aplicó una encuesta de factores ambientales a todos los sujetos participantes. La construcción y validación de la misma se realizó por un grupo de expertos. Se utilizaron medidas de resumen para variables cualitativas (porcentajes). Para valorar la asociación entre factores de riesgo se aplicó la prueba de X2 y razón de momios (Odds Ratio, OR), como medida de la fuerza de esa relación con su estimación puntual y por intervalos de confianza de 95 por ciento. Se fijó un nivel de significación de 0,05. Resultados: la exposición al humo del tabaco estuvo presente en el 75 por ciento de los niños con recurrencia de crisis de asma, con OR de 3,6; de ellos el 72,5 por ciento tenían padres fumadores, con un OR de 4,89. Conclusiones: el tabaquismo pasivo, con especial significación la presencia de padres fumadores, fue el factor de riesgo más importante para la recurrencia de las crisis de asma en el grupo de estudio(AU)

Introduction: environmental tobacco smoke is a significant risk for the health of younger children. We intend to study the role of passive smoking to asthma suffering in children. Objective: to identify the presence of passive smoking and its association with relapsing crisis in asthmatic preschool children. Methods: longitudinal case-control study (n=320) at the Allergology service of William Soler University Pediatric Hospital of Havana, in the time from February 2014 and Janu8ary 2015. We conducted an environmental factors survey to all the participant individuals. Construction and validation of such survey was carried out by a group of experts. We used summarizing measures for qualitative variables (percentages). To assess the association among risk factors we applied the chi-square test and the odds ratio, as to measure the strength of the relation with it score estimate and by confidence intervals at 95 percent. We fixed a significance level of 0.05. Results: exposition to tobacco smoke was present in 75 percent of the children with asthmatic crisis relapsing, with OR of 3.6; out of which 72.5 percent had smoking parents, with OR of 4.89. Conclusions: passive smoking, specially the presence of smoking parents, was the most important risk factor for the relapse of asthmatic crisis in the studied group(AU)

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BACKGROUND: The PIKO-6® is an electronic device that measures forced expiratory volume at seconds 1 (FEV1) and 6 (FEV6) of a forced vital capacity (FVC) maneuver. This device could aid in diagnosing obstructive respiratory diseases. OBJECTIVES: To determine the concordance of FEV1, FEV6, and the FEV1/FEV6 quotient achieved with PIKO-6® versus spirometric values from asthmatic patients, and compare results with measures from healthy children. METHODS: A cross-sectional study with asthmatic and healthy 6-to-14-year-old children, all of whom performed a forced spirometry as well as a PIKO-6® test. RESULTS: The study included 82 subjects (58 asthmatics, 24 healthy children). Except for the functional parameters, the basal characteristics of the two groups were similar. The concordance correlation coefficient (CCC) for FEV1 was 0.938 (P < 0.001), with 95% limits of agreement of -0.591 to 0.512 L, and an average of differences of -0.040 L. For FEV6, CCC was 0.927 (P < 0.001), and the 95% limits of agreement were -0.751 to 0.598 L with an average of differences of -0.077 L. The concordance analysis and the FEV1 and FEV6 associations were better in children with controlled asthma and healthy subjects, as well as in the post-bronchodilator results. CONCLUSIONS: The concordance between PIKO-6® and spirometry was lower in patients with partially controlled or uncontrolled asthma compared to controlled or healthy children. The broad limits of agreement show that the FEV1, FEV6, and FEV1/FEV6 obtained with the PIKO-6® are not interchangeable with spirometry results. Longitudinal evaluations of asthma patients are necessary to assess the utility of PIKO-6®.

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