Bronchodilator responsiveness in wheezy infants and toddlers is not associated with asthma risk factors

Background There are limited data assessing bronchodilator responsiveness (BDR) in infants and toddlers with recurrent wheezing, and factors associated with a positive response. Objectives In a multicenter study of children ≤ 36 months old, we assessed the prevalence of and factors associated with BDR among infants/toddlers with recurrent episodes of wheezing. Methods Forced expiratory flows and volumes using the raised‐volume rapid thoracic compression method were measured in 76 infants/toddlers [mean (SD) age 16.8 (7.6) months] with recurrent wheezing before and after administration of albuterol. Prior history of hospitalization or emergency department treatment for wheezing, use of inhaled or systemic corticosteroids, physician treatment of eczema, environmental tobacco smoke exposure, and family history of asthma or allergic rhinitis were ascertained. Results Using the published upper limit of normal for post bronchodilator change (FEV 0.5  ≥ 13% and/or FEF 25–75  ≥ 24%) in healthy infants, 24% (n = 18) of children in our study exhibited BDR. The BDR response was not associated with any clinical factor other than body size. Dichotomizing subjects into responders (defined by published limits of normal) or by quartile to identify children with the greatest change from baseline (4th quartile vs. other) did not identify any other factor associated with BDR. Conclusions Approximately one quarter of infants/toddlers with recurrent wheezing exhibited BDR at their clinical baseline. However, BDR in wheezy infants/toddlers was not associated with established clinical asthma risk factors. Pediatr Pulmonol. 2012; 47:421–428. © 2011 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91214/1/21567_ftp.pd

Use of fractional exhaled nitric oxide to guide the treatment of asthma an official american thoracic society clinical practice guideline

Background: The fractional exhaled nitric oxide (FENO) test is a point-of-care test that is used in the assessment of asthma.Objective: To provide evidence-based clinical guidance on whether FENO testing is indicated to optimize asthma treatment in patients with asthma in whom treatment is being considered.Methods: An international, multidisciplinary panel of experts was convened to form a consensus document regarding a single question relevant to the use of FENO. The question was selected from three potential questions based on the greatest perceived impact on clinical practice and the unmet need for evidencebased answers related to this question. The panel performed systematic reviews of published randomized controlled trials between 2004 and 2019 and followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) evidence-to-decision framework to develop recommendations. All panel members evaluated and approved the recommendations.Main Results: After considering the overall low quality of the evidence, the panel made a conditional recommendation for FENO-based care. In patients with asthma in whom treatment is being considered, we suggest that FENO is beneficial and should be used in addition to usual care. This judgment is based on a balance of effects that probably favors the intervention; the moderate costs and availability of resources, which probably favors the intervention; and the perceived acceptability and feasibility of the intervention in daily practice.Conclusions: Clinicians should consider this recommendation to measure FENO in patients with asthma in whom treatment is being considered based on current best available evidence. </p

Cultivate Primary Nasal Epithelial Cells from Children and Reprogram into Induced Pluripotent Stem Cells.

Nasal epithelial cells (NECs) are the part of the airways that respond to air pollutants and are the first cells infected with respiratory viruses. They are also involved in many airway diseases through their innate immune response and interaction with immune and airway stromal cells. NECs are of particular interest for studies in children due to their accessibility during clinical visits. Human induced pluripotent stem cells (iPSCs) have been generated from multiple cell types and are a powerful tool for modeling human development and disease, as well as for their potential applications in regenerative medicine. This is the first protocol to lay out methods for successful generation of iPSCs from NECs derived from pediatric participants for research purposes. It describes how to obtain nasal epithelial cells from children, how to generate primary NEC cultures from these samples, and how to reprogram primary NECs into well-characterized iPSCs. Nasal mucosa samples are useful in epidemiological studies related to the effects of air pollution in children, and provide an important tool for studying airway disease. Primary nasal cells and iPSCs derived from them can be a tool for providing unlimited material for patient-specific research in diverse areas of airway epithelial biology, including asthma and COPD research

Cultivate Primary Nasal Epithelial Cells from Children and Reprogram into Induced Pluripotent Stem Cells

Nasal epithelial cells (NECs) are the part of the airways that respond to air pollutants and are the first cells infected with respiratory viruses. They are also involved in many airway diseases through their innate immune response and interaction with immune and airway stromal cells. NECs are of particular interest for studies in children due to their accessibility during clinical visits. Human induced pluripotent stem cells (iPSCs) have been generated from multiple cell types and are a powerful tool for modeling human development and disease, as well as for their potential applications in regenerative medicine. This is the first protocol to lay out methods for successful generation of iPSCs from NECs derived from pediatric participants for research purposes. It describes how to obtain nasal epithelial cells from children, how to generate primary NEC cultures from these samples, and how to reprogram primary NECs into well-characterized iPSCs. Nasal mucosa samples are useful in epidemiological studies related to the effects of air pollution in children, and provide an important tool for studying airway disease. Primary nasal cells and iPSCs derived from them can be a tool for providing unlimited material for patient-specific research in diverse areas of airway epithelial biology, including asthma and COPD research

Stability of gene expression by primary bronchial epithelial cells over increasing passage number

Abstract Background An increasing number of studies using primary human bronchial epithelial cells (BECs) have reported intrinsic differences in the expression of several genes between cells from asthmatic and non-asthmatic donors. The stability of gene expression by primary BECs with increasing cell passage number has not been well characterized. Methods To determine if expression by primary BECs from asthmatic and non-asthmatic children of selected genes associated with airway remodeling, innate immune response, immunomodulatory factors, and markers of differentiated airway epithelium, are stable over increasing cell passage number, we studied gene expression patterns in passages 1, 2, 3, 4, and 5 BECs from asthmatic (n = 6) and healthy (n = 6) subjects that were differentiated at an air-liquid interface. RNA was harvested from BECs and RT-PCR was performed for TGFβ1, TGFβ2, activin A, FSTL3, MUC5AC, TSLP, IL-33, CXCL10, IFIH1, p63, KT5, TUBB4A, TJP1, OCLN, and FOXJ1. Results Expression of TGFβ1, TGFβ2, activin A, FSTL3, MUC5AC, CXCL10, IFIH1, p63, KT5, TUBB4A, TJP1, OCLN, and FOXJ1 by primary BECs from asthmatic and healthy children was stable with no significant differences between passages 1, 2 and 3; however, gene expression at cell passages 4 and 5 was significantly greater and more variable compared to passage 1 BECs for many of these genes. IL-33 and FOXJ1 expression was also stable between passages 1 through 3, however, expression at passages 4 and 5 was significantly lower than by passage 1 BECs. TSLP, p63, and KRT5 expression was stable across BEC passages 1 through 5 for both asthmatic and healthy BECs. Conclusions These observations illustrate the importance of using BECs from passage ≤3 when studying gene expression by asthmatic and non-asthmatic primary BECs and characterizing the expression pattern across increasing cell passage number for each new gene studied, as beyond passage 3 genes expressed by primary BECs appear to less accurately model in vivo airway epithelial gene expression

Additional file 1 of Stability of gene expression by primary bronchial epithelial cells over increasing passage number

Primary quantitative PCR datasets. (XLSX 37 kb

Additional file 5: of Stability of gene expression by primary bronchial epithelial cells over increasing passage number

Figure S4. Un-normalized mRNA expression of innate immunity and immunomodulatory genes by primary BECs. Un-normalized mRNA Ct values for CXCL10 (A.), IFIH1 (B.), IL-33 (C.), and TSLP (D.) by BECs at P1 (n = 6 asthma donors, n = 6 healthy donors), P2 (n = 6 asthma donors, n = 6 healthy donors), P3 (n = 4 asthma donors, n = 6 healthy donors), P4 (n = 6 asthma donors, n = 6 healthy donors), and P5 (n = 6 asthma donors, n = 6 healthy donors) are presented as individual data points for each donor cell line. To compare expression of genes at P2-P5 to expression at P1, and to compare patterns of gene expression between asthmatic and healthy donors, ordinary two-way ANOVA with Dunnett’s multiple comparisons test was used for normally distributed data, and Kruskal-Wallis ANOVA with Dunn’s multiple comparisons test was used for non-normally distributed data. (EMF 155 kb

Additional file 6: of Stability of gene expression by primary bronchial epithelial cells over increasing passage number

Figure S5. Un-normalized mRNA expression of genes associated with airway epithelial basal cells, ciliogenesis, and epithelial tight junctions by primary BECs. Un-normalized mRNA Ct values for TP63 (A.), KRT5 (B.), TUBB4A (C.), TPJ1 (D.), FOXJ1 (E.), and OCLN (F.) by BECs at P1 (n = 6 asthma donors, n = 6 healthy donors), P2 (n = 6 asthma donors, n = 6 healthy donors), P3 (n = 4 asthma donors, n = 6 healthy donors), P4 (n = 6 asthma donors, n = 6 healthy donors), and P5 (n = 6 asthma donors, n = 6 healthy donors) are presented as individual data points for each donor cell line. To compare expression of genes at P2-P5 to expression at P1, and to compare patterns of gene expression between asthmatic and healthy donors, ordinary two-way ANOVA with Dunnett’s multiple comparisons test was used for normally distributed data, and Kruskal-Wallis ANOVA with Dunn’s multiple comparisons test was used for non-normally distributed data. (EMF 224 kb