Project description:Rationale: Cross-sectional studies suggest an exacerbation-prone asthma (EPA) phenotype and the utility of blood eosinophils and plasma IL-6 as predictive biomarkers.Objectives: To prospectively test for EPA phenotype and utility of baseline blood measures of eosinophils and IL-6 as predictive biomarkers.Methods: Three-year asthma exacerbation data were analyzed in 406 adults in the Severe Asthma Research Program-3. Transition models were used to assess uninformed and informed probabilities of exacerbation in year 3. Binomial regression models were used to assess eosinophils and IL-6 as predictive biomarkers.Measurements and Main Results: Eighty-three participants (21%) had ≥1 exacerbation in each year (EPA) and 168 participants (41%) had no exacerbation in any year (exacerbation-resistant asthma). The uninformed probability of an exacerbation in Year 3 was 40%, but the informed probability increased to 63% with an exacerbation in Year 2 and 82% with an exacerbation in Years 1 and 2. The probability of a Year 3 exacerbation with no Year 1 or 2 exacerbations was 13%. Compared with exacerbation-resistant asthma, EPA was characterized by lower FEV1 and a higher prevalence of obesity, hypertension, and diabetes. High-plasma IL-6 occurred in EPA, and the incident rate ratio for exacerbation increased 10% for each 1-pg/μl increase in baseline IL-6 level. Although high blood eosinophils did not occur in EPA, the incident rate ratio for exacerbations increased 9% for each 100-cell/μl increase in baseline eosinophil number.Conclusions: Longitudinal analysis confirms an EPA phenotype characterized by features of metabolic dysfunction. Blood measures of IL-6, but not eosinophils, were significantly associated with EPA, and IL-6 and eosinophils predicted exacerbations in the sample as a whole.
Project description:Patients who are prone to exacerbations of asthma experience significant costs in terms of missed work and school, acute care visits, and hospitalizations. Exacerbations are largely driven by environmental exposures including pollutants, stress, and viral and bacterial pathogens. These exposures are most likely to induce acute severe "asthma attacks" in high-risk patients. These personal risk factors for exacerbations can vary with the phenotype of asthma and age of the patient. In children, allergic sensitization is a strong risk factor, especially for those children who develop sensitization early in life. Airway inflammation is an important risk factor, and biomarkers are under evaluation for utility in detecting eosinophilic and type 2 inflammation and neutrophilic inflammation as indicators of risk for recurrent exacerbations. Insights into inflammatory mechanisms have led to new approaches to prevent exacerbations using mAb-based biologics that target specific type 2 pathways. Challenges remain in developing an evidence base to support precision interventions with these effective yet expensive therapies, and in determining whether these treatments will be safe and effective in young children. Unfortunately, there has been less progress in developing treatments for acute exacerbations. Hopefully, greater understanding of mechanisms relating airway viruses, bacteria, mucin production, and neutrophilic inflammatory responses will lead to additional treatment options for patients experiencing acute exacerbations.
Project description:Background and objectivesChronic inflammatory airway diseases, including asthma and chronic obstructive pulmonary disease (COPD), are complex syndromes with diverse clinical symptoms due to multiple pathophysiological conditions. In this study, using common and shared risk factors for the exacerbation of asthma and COPD, we sought to clarify the exacerbation-prone phenotypes beyond disease labels, and to specifically investigate the role of the IL4RA gene polymorphism, which is related to type 2 inflammation, in these exacerbation-prone phenotypes.MethodsThe study population comprised patients with asthma (n = 117), asthma-COPD overlap (ACO; n = 37) or COPD (n = 48) and a history of exacerbation within the previous year. Cluster analyses were performed using factors associated with both asthma and COPD exacerbation. The association of the IL4RA gene polymorphism rs8832 with each exacerbation-prone phenotype was evaluated by multinomial logistic analyses using non-asthma non-COPD healthy adults as controls (n = 1,529). In addition, the genetic influence of rs8832 was also examined in asthma patients with allergic rhinitis and no history of exacerbation (n = 130).ResultsTwo-step cluster analyses identified five clusters that did not necessarily correspond to the diagnostic disease labels. Cluster 1 was characterized by high eosinophil counts, cluster 2 was characterized by smokers with impaired lung function, cluster 3 was characterized by the presence of gastroesophageal reflux, cluster 4 was characterized by non-allergic females, and cluster 5 was characterized by allergic rhinitis and elevated total immunoglobulin E levels. A significant association with rs8832 was observed for cluster 5 (odds ratio, 3.88 (1.34-11.26), p = 0.013) and also for the type 2 exacerbation-prone phenotypes (clusters 1 and 5: odds ratio, 2.73 (1.45-5.15), p = 1.9 × 10-3).DiscussionOur results indicated that the clinical heterogeneity of disease exacerbation may reflect the presence of common exacerbation-prone endotypes across asthma and COPD, and may support the use of the treatable traits approach for the prevention of exacerbations in patients with chronic inflammatory airway diseases.
Project description:BackgroundMinority groups of African descent experience disproportionately greater asthma morbidity compared with other racial groups, suggesting that genetic variation from a common ancestry could influence exacerbation risk.ObjectiveWe evaluated clinical trial measures in the context of self-reported race and genetic ancestry to identify risk factors for asthma exacerbations.MethodsOne thousand eight hundred forty multiethnic subjects from 12 Asthma Clinical Research Network and AsthmaNet trials were analyzed for incident asthma exacerbations with Poisson regression models that included clinical measures, self-reported race (black, non-Hispanic white, and other), and estimates of global genetic African ancestry in a subgroup (n = 760).ResultsTwenty-four percent of 1840 subjects self-identified as black. Black and white subjects had common risk factors for exacerbations, including a history of 2 or more exacerbations in the previous year and FEV1 percent predicted values, whereas chronic sinusitis, allergic rhinitis, and gastroesophageal reflux disease were only associated with increased exacerbation risk in black subjects. In the combined multiethnic cohort, neither race (P = .30) nor percentage of genetic African ancestry as a continuous variable associated with exacerbation risk (adjusted rate ratio [RR], 1.26 [95% CI, 0.94-1.70; P = .13]; RR per 1-SD change [32% ancestry], 0.97 [95% CI, 0.78-1.19; P = .74]). However, in 161 black subjects with genetic data, those with African ancestry greater than the median (≥82%) had a significantly greater risk of exacerbation (RR, 3.06 [95% CI, 1.09-8.6; P = .03]).ConclusionBlack subjects have unique risk factors for asthma exacerbations, of which global African genetic ancestry had the strongest effect.
Project description:The Precision Interventions for Severe and/or Exacerbation-prone Asthma (PrecISE) study is an adaptive platform trial designed to investigate novel interventions to severe asthma. The study is conducted under a master protocol and utilizes a crossover design with each participant receiving up to five interventions and at least one placebo. Treatment assignments are based on the patients' biomarker profiles and precision health methods are incorporated into the interim and final analyses. We describe key elements of the PrecISE study including the multistage adaptive enrichment strategy, early stopping of an intervention for futility, power calculations, and the primary analysis strategy.
Project description:Background: Some children with asthma remain poorly controlled and have recurrent exacerbations despite treatment with inhaled corticosteroids. Aside from prior exacerbations, there are currently no reliable predictors of exacerbation-prone asthma in these children and limited understanding of potential underlying mechanisms. Objective: We sought to quantify small molecules in the plasma of children with exacerbation- prone asthma through mass spectrometry-based metabolomics. We hypothesized that the plasma metabolome of these children would differ from that of children with non-exacerbation- prone asthma. Methods: Plasma metabolites were extracted from four pediatric asthma cohorts (n=215 total, n=41 with exacerbation-prone asthma) and detected using a ZIC-HILIC column coupled to a Q Exactive HF mass spectrometer. High-confidence annotations were retained for univariate analysis and were confirmed by a sensitivity analysis in subjects on high-dose inhaled corticosteroids. Metabolites that varied by cohort were excluded. Metaboanalyst was used to identify pathways of interest. Concentrations were calculated by reference standardization to NIST SRM 1950. Results: We identified 32 unique, cohort-independent metabolites that differed in children with exacerbation-prone asthma compared to children with non-exacerbation-prone asthma. Comparison of metabolite concentrations to literature-reported values for healthy children revealed that most metabolites were decreased in both asthma groups, but more so in exacerbation-prone asthma. Pathway analysis identified arginine, lysine, and methionine pathways as most impacted. Conclusions: Several plasma metabolites are perturbed in children with exacerbation-prone asthma and are largely related to arginine, lysine, and methionine pathways. While validation is needed, plasma metabolites may be potential biomarkers for exacerbation-prone asthma in children.
Project description:Asthma is a heterogeneous disease, with multiple underlying inflammatory pathways and structural airway abnormalities that impact disease persistence and severity. Recent progress has been made in developing targeted asthma therapeutics, especially for subjects with eosinophilic asthma. However, there is an unmet need for new approaches to treat patients with severe and exacerbation-prone asthma, who contribute disproportionately to disease burden. Extensive deep phenotyping has revealed the heterogeneous nature of severe asthma and identified distinct disease subtypes. A current challenge in the field is to translate new and emerging knowledge about different pathobiologic mechanisms in asthma into patient-specific therapies, with the ultimate goal of modifying the natural history of disease. Here, we describe the Precision Interventions for Severe and/or Exacerbation-Prone Asthma (PrecISE) Network, a groundbreaking collaborative effort of asthma researchers and biostatisticians from around the United States. The PrecISE Network was designed to conduct phase II/proof-of-concept clinical trials of precision interventions in the population with severe asthma, and is supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health. Using an innovative adaptive platform trial design, the PrecISE Network will evaluate up to 6 interventions simultaneously in biomarker-defined subgroups of subjects. We review the development and organizational structure of the PrecISE Network, and choice of interventions being studied. We hope that the PrecISE Network will enhance our understanding of asthma subtypes and accelerate the development of therapeutics for severe asthma.
Project description:Asthma exacerbation (AE) usually denotes worsening of asthma symptoms that requires intense management to prevent further deterioration. AE has been reported to correlate with clinical and demographic factors, such as race, gender, and treatment compliance as well as environmental factors, such as viral infection, smoking, and air pollution. In addition, recent observations suggest that there are likely to be genetic factors specific to AE. Understanding genetic factors specific to AE is essential to develop therapy tailored for exacerbation-prone asthma. Here, we summarize the results of studies involving genetic risk factors for AE. To simplify and enhance understanding, we reviewed the studies according to the following categories: hypothesis-driven approaches, hypothesis-free approaches, gene-environment interactions, and pharmacogenetics.
Project description:Background: Clinical transcriptomics of peripheral blood mononuclear cells (PBMC) are coming into focus as a surrogate approach for prognosis, diagnosis, biomarker discovery and examination disease mechanisms. However, bioassays paired with transcriptomic analytic tools are yet to be developed and made available at point of care. Harnessing personal dynamic genomic responses to tailor patient asthma treatment or prevent disease exacerbations remain unmet medical needs. Method: We developed a rhinovirus-stimulated peripheral blood based-assay (virogram assay) coupled with single-subject analytics (N-of-1-patwhays) to capture dynamic genome-wide expression and dysregulated pathways to retrospectively predict childhood asthma exacerbation. We hypothesized that some genomic factors might predispose any given individual, healthy or asthmatic, to a set of similar transcriptional responses to rhinovirus stimulation. We first generated a classifier from paired sample microarrays, control and stimulated PBMC from healthy subjects and applied this classifier on the transcriptomic analysis of control and HRV-stimulated PBMC samples (virogram assay) from children with asthma. Results: The analysis of the different genomic responses of single-subject paired PBMC samples (HRV-stimulated and control) derived from healthy individuals (external dataset) enabled the discovery of dysregulated pathways related to acquired immunity, epigenetics and morphogenesis. The classifier built on these results and applied on the transcriptional analysis derived from the virogram assay predicted that the risk of asthma exacerbation among asthmatic subjects with an accuracy of 70%. Conclusion: We provide evidence that clinical prognosis can be predicted with a PBMC based-bioassay aligned with adequate single-subject analytics to assess dynamic transcriptomic response to specific disease-associated stimuli.
Project description:Asthma exacerbation may require a visit to the emergency room as well as hospitalization and can occasionally be fatal. However, there is limited information about the prognostic factors for asthma exacerbation requiring hospitalization, and no methods are available to predict an inpatient's prognosis. We investigated the clinical features and factors affecting in-hospital mortality of patients with asthma exacerbation and generated a nomogram to predict in-hospital death using a national inpatient database in Japan.We retrospectively collected data concerning hospitalization of adult patients with asthma exacerbation between July 2010 and March 2013 using the Japanese Diagnosis Procedure Combination database. We recorded patient characteristics and performed Cox proportional hazards regression analysis to assess the factors associated with all-cause in-hospital mortality. Then, we constructed a nomogram to predict in-hospital death.A total of 19,684 patients with asthma exacerbation were identified; their mean age was 58.8 years (standard deviation, 19.7 years) and median length of hospital stay was 8 days (interquartile range, 5-12 days). Among study patients, 118 died in the hospital (0.6%). Factors associated with higher in-hospital mortality included older age, male sex, reduced level of consciousness, pneumonia, and heart failure. A nomogram was generated to predict the in-hospital death based on the existence of seven variables at admission. The nomogram allowed us to estimate the probability of in-hospital death, and the calibration plot based on these results was well fitted to predict the in-hospital prognosis.Our nomogram allows physicians to predict individual risk of in-hospital death in patients with asthma exacerbation.