Lung function decline and variable airway inflammatory pattern: longitudinal analysis of severe asthma

Lung function trajectories in a cohort of patients with moderate-to-severe asthma on mepolizumab, omalizumab, or dupilumab

BACKGROUND

Lung function is an independent predictor of mortality. We evaluated the lung function trajectories of a cohort of patients with asthma receiving biologic therapy.

METHODS

We identified 229 monoclonal antibody-naïve adult patients with moderate-to-severe asthma who initiated omalizumab, mepolizumab, or dupilumab between 2010 and 2022 in a large healthcare system in Boston, MA. Generalized additive mixed models were used to estimate the lung function trajectories during the 156 weeks following biologic initiation. Response was defined as an improvement in FEV1 or a decrease of ≤0.5% per year. The Kaplan-Meier estimator was used to assess time to no additional improvement in FEV1 in responders. All models were adjusted for age, sex, body mass index, smoking status, baseline exacerbation rate, and baseline blood eosinophil count.

RESULTS

Eighty-eight patients initiated mepolizumab, 76 omalizumab, and 65 dupilumab. Baseline eosinophil count was highest in the mepolizumab group (405 cells/mcL) and lowest for omalizumab (250 cells/mcL). Both FEV1 and FVC improved in the mepolizumab group (FEV1 + 20 mL/year; FVC +43 mL/year). For omalizumab, there was an initial improvement in the first year followed by decline with an overall FEV1 loss of -44 mL/year and FVC -32 mL/year. For dupilumab, both FEV1 (+61 mL/year) and FVC (+74 mL/year) improved over time. Fifty percent of the mepolizumab group, 58% omalizumab, and 72% of dupilumab were responders. The median time to no additional FEV1 improvement in responders was 24 weeks for omalizumab, 48 weeks for mepolizumab, and 57 weeks for dupilumab.

CONCLUSION

In this clinical cohort, mepolizumab, omalizumab, and dupilumab had beneficial effects on FEV1 and FVC with distinct post-initiation trajectories.

Association of Small Airway Functional Indices With Respiratory Symptoms and Comorbidity in Asthmatics: A National Cross-Sectional Study

Background

Small airway dysfunction (SAD) and airway inflammation are vital in asthma exacerbations. Type 2 inflammation (T2), mediated by cytokines from T helper 2 cell (Th2) such as interleukin (IL)-4, IL-5, and IL-13, is a potential mechanism underlying SAD. Research on small airway function in asthma is limited. We aimed to explore the correlation between small airway function and respiratory symptoms and comorbidity in T2 and non-T2 asthma.

Methods

Derived from the National Health and Nutrition Examination Survey (NHANES), our study encompassed 2,420 asthma patients aged 6 - 79 years, including pulmonary function (PF) data such as forced expiratory flow between 25% and 75% of forced vital capacity (FEF25-75), forced expiratory volume in 1 second (FEV1), forced expiratory volume in 3 seconds (FEV3), forced expiratory volume in 6 seconds (FEV6), and forced vital capacity (FVC). To evaluate the small airway function, we calculated z-scores for FEF25-75, FEF25-75/FVC, FEV1/FEV6, and FEV3/FEV6. Logistic regression determined the adjusted odds ratios (aORs) for symptoms and comorbidity.

Results

FEF25-75, FEV1/FEV6, and FEV3/FEV6 correlated with asthmatic symptoms. FEF25-75 had the strongest association with wheezing or whistling attacks. An increase of 1 standard deviations (SD) in FEF25-75 reduced recurrent wheezing (aOR: 0.70; 95% confidence intervals (95% CIs): 0.65 - 0.76) and severe attacks (aOR: 0.67; 95% CI: 0.62 - 0.94). These indices were also linked to dry cough and hay fever, particularly FEV3/FEV6 reducing hay fever risk (aOR: 0.70; 95% CI: 0.55 - 0.91) in non-T2 asthma. FEF25-75/FVC related to persistent (aOR: 0.78; 95% CI: 0.72 - 0.84) and severe attacks (aOR: 1.14; 95% CI: 1.08 - 1.22) in non-T2 groups. Lower indices combined with T2 exposure raised severe attack risk.

Conclusions

In this nationwide study, small airway function correlated with symptom onset, especially in T2 asthma. Small airway injury differed between T2 and non-T2 asthma. Prospective research is needed to establish reference values.

Elevated Eosinophil Counts in Acute Exacerbations of Bronchiectasis: Unveiling a Distinct Clinical Phenotype

BACKGROUND

Non-cystic fibrosis bronchiectasis is a chronic respiratory disease characterized by bronchial dilation. However, the significance of elevated eosinophil counts in acute exacerbations of bronchiectasis remains unclear.

METHODS

This retrospective case-control study included 169 hospitalized patients with acute exacerbations of non-cystic fibrosis bronchiectasis. Based on blood eosinophil levels, patients were categorized into eosinophilic and non-eosinophilic bronchiectasis groups. Various clinical variables, including lung function, comorbidities and clinical features were collected for analysis. The study aimed to examine the differences between these groups and their clinical phenotypes.

RESULTS

Eosinophilic bronchiectasis (EB) was present in approximately 22% of all hospitalized patients with bronchiectasis, and it was more prevalent among male smokers (P < 0.01). EB exhibited greater severity of bronchiectasis, including worse airway obstruction, higher scores in the E-FACED (FACED combined with exacerbations) and bronchiectasis severity index (BSI), a high glucocorticoids medication possession ratio, and increased hospitalization cost (P < 0.05 or P < 0.01). Furthermore, we observed a significant positive correlation between blood eosinophil count and both sputum eosinophils (r = 0.49, P < 0.01) and serum total immunoglobulin E levels (r = 0.21, P < 0.05). Additional analysis revealed that patients with EB had a higher frequency of shortness of breath (P < 0.05), were more likely to have comorbid sinusitis (P < 0.01), and exhibited a greater number of lung segments affected by bronchiectasis (P < 0.01).

CONCLUSIONS

These findings suggest that EB presents a distinct pattern of bronchiectasis features, confirming the notion that it is a specific phenotype.

Predictors of Early and Late Lung Function Improvement in Severe Eosinophilic Asthma on Type2-Biologics in the PRISM Study

BACKGROUND

The determinants linked to the short- and long-term improvement in lung function in patients with severe eosinophilic asthma (SEA) on biological treatment (BioT) remain elusive.

OBJECTIVE

We sought to identify the predictors of early and late lung function improvement in patients with SEA after BioT.

METHODS

140 adult patients with SEA who received mepolizumab, dupilumab, or reslizumab were followed up for 6 months to evaluate improvement in forced expiratory volume in one second (FEV1). Logistic regression was used to determine the association between potential prognostic factors and improved lung function at 1 and 6 months of treatment.

RESULTS

More than a third of patients with SEA using BioT showed early and sustained improvements in FEV1 after 1 month. A significant association was found between low baseline FEV1 and high blood eosinophil count and sustained FEV1 improvement after 1 month (0.54 [0.37-0.79] and 1.88 [1.28-2.97] odds ratios and 95% confidence interval, respectively). Meanwhile, among patients who did not experience FEV1 improvement after 1 month, 39% exhibited improvement at 6 months follow-up. A high ACT score measured at this visit was the most reliable predictor of late response after 6 months of treatment (OR and 95% CI 1.75 [1.09-2.98]).

CONCLUSION

Factors predicting the efficacy of biological agents that improve lung function in SEA vary according to the stage of response.

Suppression of SPARC Ameliorates Ovalbumin-induced Airway Remodeling via TGFβ1/Smad2 in Chronic Asthma

PURPOSE

Airway remodeling is a critical feature of asthma. Secreted protein acidic and rich in cysteine (SPARC), which plays a cardinal role in regulating cell-matrix interactions, has been implicated in various fibrotic diseases. However, the effect of SPARC in asthma remains unknown.

METHODS

We studied the expression of SPARC in human bronchial epithelial cells and serum of asthmatics as well as in the lung tissues of chronic asthma mice. The role of SPARC was examined by using a Lentivirus-mediated SPARC knockdown method in the ovalbumin (OVA)-induced asthma mice. The biological processes regulated by SPARC were identified using RNA sequencing. The function of SPARC in the remodeling process induced by transforming growth factor β1 (TGFβ1) was conducted by using SPARC small interfering RNA (siRNA) or recombinant human SPARC protein in 16HBE cells.

RESULTS

We observed that SPARC was up-regulated in human bronchial epithelia of asthmatics and the asthmatic mice. The levels of serum SPARC in asthmatics were also elevated and negatively correlated with the forced expiratory volume in one second (FEV1) to forced vital capacity ratio (FVC) (r = -0.485, P < 0.01) and FEV1 (%predicted) (r = -0.425, P = 0.001). In the chronic asthmatic mice, Lentivirus-mediated SPARC knockdown significantly decreased airway remodeling and airway hyper-responsiveness. According to gene set enrichment analysis, negatively enriched pathways found in the OVA + short hairpin-SPARC group included ECM organization and collagen formation. In the lung function studies, knockdown of SPARC by siRNA reduced the expression of remodeling-associated biomarkers, cell migration, and contraction by blocking the TGFβ1/Smad2 pathway. Addition of human recombinant SPARC protein promoted the TGFβ1-induced remodeling process, cell migration, and contraction in 16HBE cells via the TGFβ1/Smad2 pathway.

CONCLUSIONS

Our studies provided evidence for the involvement of SPARC in the airway remodeling of asthma via the TGFβ1/Smad2 pathway.

Shared genetic architecture of blood eosinophil counts and asthma in UK Biobank

Rationale

Asthma is a complex, heterogeneous disease strongly associated with type 2 inflammation, and blood eosinophil counts guide therapeutic interventions in moderate and severe asthma. Eosinophils are leukocytes involved in type 2 immune responses. Despite these critical associations between asthma and blood eosinophil counts, the shared genetic architecture of these two traits remains unknown. The objective of the present study was to characterise the genetic architecture of blood eosinophil counts and asthma in the UK Biobank.

Methods

We performed genome-wide association studies (GWAS) of doctor-diagnosed asthma, blood eosinophil, neutrophil, lymphocyte and monocyte counts in the UK Biobank. Genetic correlation analysis was performed on GWAS results and validated in the Trans-National Asthma Genetic Consortium (TAGC) study of asthma.

Results

GWAS of doctor-diagnosed asthma and blood eosinophil counts in the UK Biobank identified 585 and 3429 significant variants, respectively. STAT6, a transcription factor involved in interleukin-4 signalling, was a key shared pathway between asthma and blood eosinophil counts. Genetic correlation analysis demonstrated a positive correlation between doctor-diagnosed asthma and blood eosinophil counts (r=0.38±0.10, correlation±se; p=4.7×10-11). As a validation of this association, we found a similar correlation between TAGC and blood eosinophil counts in the UK Biobank (0.37±0.08, correlation±se; p=1.2×10-6).

Conclusions

These findings define the shared genetic architecture between blood eosinophil counts and asthma risk in subjects of European ancestry and point to a genetic link to the STAT6 signalling pathway in these two traits.

Clinical Implications of Longitudinal Blood Eosinophil Counts in Patients With Severe Asthma

BACKGROUND

The stability and variability of blood eosinophil counts (BECs) to phenotype patients with severe asthma is not fully understood.

OBJECTIVE

This post hoc, longitudinal, pooled analysis of placebo-arm patients from 2 phase 3 studies evaluated the clinical implications of BEC stability and variability in moderate-to-severe asthma.

METHODS

This analysis included patients from SIROCCO and CALIMA who received maintenance medium- to high-dosage inhaled corticosteroids plus long-acting β2-agonists; 2:1 patients with BECs of 300 cells/μL or higher and less than 300 cells/μL were enrolled. The BECs were measured 6 times over 1 year in a centralized laboratory. Exacerbations, lung function, and Asthma Control Questionnaire 6 scores were documented across patients grouped by BEC (<300 cells/μL or ≥300 cells/μL) and variability (<80% or ≥80% BECs less than or greater than 300 cells/μL).

RESULTS

Among 718 patients, 42.2% (n = 303) had predominantly high, 30.9% (n = 222) had predominantly low, and 26.9% (n = 193) had variable BECs. Prospective exacerbation rates (mean ± SD) were significantly greater in patients with predominantly high (1.39 ± 2.20) and variable (1.41 ± 2.09) BECs versus predominantly low (1.05 ± 1.66) BECs. Similar results were observed for the number of exacerbations while on placebo.

CONCLUSIONS

Although patients with variable BECs had intermittently high and low BECs, they experienced similar exacerbation rates to the predominantly high group, which were greater than those in the predominantly low group. A high BEC supports an eosinophilic phenotype in clinical settings without additional measurements, whereas a low BEC requires repeated measurements because it could reflect intermittently high or predominantly low BECs.

Severe Asthma Standard-of-Care Background Medication Reduction With Benralizumab: ANDHI in Practice Substudy

BACKGROUND

The phase IIIb, randomized, parallel-group, placebo-controlled ANDHI double-blind (DB) study extended understanding of the efficacy of benralizumab for patients with severe eosinophilic asthma. Patients from ANDHI DB could join the 56-week ANDHI in Practice (IP) single-arm, open-label extension substudy.

OBJECTIVE

Assess potential for standard-of-care background medication reductions while maintaining asthma control with benralizumab.

METHODS

Following ANDHI DB completion, eligible adults were enrolled in ANDHI IP. After an 8-week run-in with benralizumab, there were 5 visits to potentially reduce background asthma medications for patients achieving and maintaining protocol-defined asthma control with benralizumab. Main outcome measures for non-oral corticosteroid (OCS)-dependent patients were the proportions with at least 1 background medication reduction (ie, lower inhaled corticosteroid dose, background medication discontinuation) and the number of adapted Global Initiative for Asthma (GINA) step reductions at end of treatment (EOT). Main outcomes for OCS-dependent patients were reductions in daily OCS dosage and proportion achieving OCS dosage of 5 mg or lower at EOT.

RESULTS

For non-OCS-dependent patients, 53.3% (n = 208 of 390) achieved at least 1 background medication reduction, increasing to 72.6% (n = 130 of 179) for patients who maintained protocol-defined asthma control at EOT. A total of 41.9% (n = 163 of 389) achieved at least 1 adapted GINA step reduction, increasing to 61.8% (n = 110 of 178) for patients with protocol-defined EOT asthma control. At ANDHI IP baseline, OCS dosages were 5 mg or lower for 40.4% (n = 40 of 99) of OCS-dependent patients. Of OCS-dependent patients, 50.5% (n = 50 of 99) eliminated OCS and 74.7% (n = 74 of 99) achieved dosages of 5 mg or lower at EOT.

CONCLUSIONS

These findings demonstrate benralizumab's ability to improve asthma control, thereby allowing background medication reduction.

Relationships Between High-Resolution Computed Tomographic Features and Lung Function Trajectory in Patients With Asthma

PURPOSE

A subset of asthmatics suffers from persistent airflow limitation, known as remodeled asthma, despite optimal treatment. Typical quantitative scoring methods to evaluate structural changes of airway remodeling on high-resolution computed tomography (HRCT) are time-consuming and laborious. Thus, easier and simpler methods are required in clinical practice. We evaluated the clinical usefulness of a simple, semi-quantitative method based on 8 HRCT parameters by comparing asthmatics with a persistent decline of post-bronchodilator (BD)-FEV1 to those with a BD-FEV1 that normalized over time and evaluated the relationships of the parameters with BD-FEV1.

METHODS

Asthmatics (n = 59) were grouped into 5 trajectories (Trs) according to the changes of BD-FEV1 over 1 year. After 9-12 months of guideline-based treatment, HRCT parameters including emphysema, bronchiectasis, anthracofibrosis, bronchial wall thickening (BWT), fibrotic bands, mosaic attenuation on inspiration, air-trapping on expiration, and centrilobular nodules were classified as present (1) or absent (0) in 6 zones.

RESULTS

The Tr5 group (n = 11) was older and exhibited a persistent decline in BD-FEV1. The Tr5 and Tr4 groups (n = 12), who had a lower baseline BD-FEV1 that normalized over time, had longer durations of asthma, frequent exacerbations, and higher doses of steroid use compared to the Tr1-3 groups (n = 36), who had a normal baseline BD-FEV1. The Tr5 group had higher emphysema and BWT scores than the Tr4 (P = 8.25E-04 and P = 0.044, respectively). Scores for the other 6 parameters were not significantly different among the Tr groups. BD-FEV1 was inversely correlated with the emphysema and BWT scores in multivariate analysis (P = 1.70E-04, P = 0.006, respectively).

CONCLUSIONS

Emphysema and BWT are associated with airway remodeling in asthmatics. Our simple, semi-quantitative scoring system based on HRCT may be an easy-to-use method for estimating airflow limitation.

Critical evaluation of asthma biomarkers in clinical practice

The advent of personalized medicine has revolutionized the whole approach to the management of asthma, representing the essential basis for future developments. The cornerstones of personalized medicine are the highest precision in diagnosis, individualized prediction of disease evolution, and patient-tailored treatment. To this aim, enormous efforts have been established to discover biomarkers able to predict patients' phenotypes according to clinical, functional, and bio-humoral traits. Biomarkers are objectively measured characteristics used as indicators of biological or pathogenic processes or clinical responses to specific therapeutic interventions. The diagnosis of type-2 asthma, prediction of response to type-2 targeted treatments, and evaluation of the risk of exacerbation and lung function impairment have been associated with biomarkers detectable either in peripheral blood or in airway samples. The surrogate nature of serum biomarkers, set up to be less invasive than sputum analysis or bronchial biopsies, has shown several limits concerning their clinical applicability. Routinely used biomarkers, like peripheral eosinophilia, total IgE, or exhaled nitric oxide, result, even when combined, to be not completely satisfactory in segregating different type-2 asthma phenotypes, particularly in the context of severe asthma where the choice among different biologics is compelling. Moreover, the type-2 low fraction of patients is not only an orphan of biological treatments but is at risk of being misdiagnosed due to the low negative predictive value of type-2 high biomarkers. Sputum inflammatory cell analysis, considered the highest specific biomarker in discriminating eosinophilic inflammation in asthma, and therefore elected as the gold standard in clinical trials and research models, demonstrated many limits in clinical applicability. Many factors may influence the measure of these biomarkers, such as corticosteroid intake, comorbidities, and environmental exposures or habits. Not least, biomarkers variability over time is a confounding factor leading to wrong clinical choices. In this narrative review, we try to explore many aspects concerning the role of routinely used biomarkers in asthma, applying a critical view over the "state of the art" and contemporarily offering an overview of the most recent evidence in this field.

Asthma exacerbations are associated with a decline in lung function: a longitudinal population-based study

RATIONALE

Progressive lung function (LF) decline in patients with asthma contributes to worse outcomes. Asthma exacerbations are thought to contribute to this decline; however, evidence is limited with mixed results.

METHODS

This historical cohort study of a broad asthma patient population in the Optimum Patient Care Research Database, examined asthma patients with 3+eligible post-18th birthday peak expiratory flow rate (PEF) records (primary analysis) or records of forced expiratory flow in 1 s (FEV₁) (sensitivity analysis). Adjusted linear growth models tested the association between mean annual exacerbation rate (AER) and LF trajectory.

RESULTS

We studied 1 09 182 patients with follow-up ranging from 5 to 50 years, of which 75 280 had data for all variables included in the adjusted analyses. For each additional exacerbation, an estimated additional -1.34 L/min PEF per year (95% CI -1.23 to -1.50) were lost. Patients with AERs >2/year and aged 18-24 years at baseline lost an additional -5.95 L/min PEF/year (95% CI -8.63 to -3.28) compared with those with AER 0. These differences in the rate of LF decline between AER groups became progressively smaller as age at baseline increased. The results using FEV₁ were consistent with the above.

CONCLUSION

To our knowledge, this study is the largest nationwide cohort of its kind and demonstrates that asthma exacerbations are associated with faster LF decline. This was more prominent in younger patients but was evident in older patients when it was related to lower starting LF, suggesting a persistent deteriorating phenotype that develops in adulthood over time. Earlier intervention with appropriate management in younger patients with asthma could be of value to prevent excessive LF decline.

Anti-Interleukin-5 Therapy Is Associated with Attenuated Lung Function Decline in Severe Eosinophilic Asthma Patients from the Belgian Severe Asthma Registry

BACKGROUND

Asthmatics have accelerated lung function decline over time compared with healthy individuals.

OBJECTIVE

To evaluate risk factors for accelerated lung function decline.

METHODS

In a longitudinal analysis on severe asthmatics enrolled in the Belgian Severe Asthma Registry with at least 2 visits a minimum of 12 months apart, we compared characteristics of patients with and without decline (loss of post-bronchodilation forced expiratory volume in 1 s [FEV₁] (% predicted)/y greater than zero) over time. Multiple linear regression was applied to study the factors independently associated with FEV₁ decline.

RESULTS

In the overall population (n = 318), median annual FEV₁ decline was 0.27 (-4.22 to 3.80) % predicted/y over a period of 23 months (12-41 months). Asthma was less controlled at baseline in nondecliners than in decliners (53%). Lung function and residual volume at baseline were higher in the declining group. Decliners presented with increased bronchial reactivity (ie, a lower provocative concentration of methacholine causing a 20% fall in FEV₁) at baseline. Twenty-five percent of nondecliners were started on anti-interleukin-5 (anti-IL-5) for severe eosinophilic asthma during the study compared with 10% of decliners. The multivariable model suggested that Asthma Control Questionnaire score at baseline, late-onset asthma, and addition of anti-IL-5 during follow-up were associated with lower FEV₁ decline, independently from other variables such as evolution in exacerbations, smoking status, inhaled corticosteroids or oral corticosteroids dose, or add-on anti-immunoglobulin E over time, whereas reversibility to salbutamol and higher FEV₁ were associated with accelerated FEV₁ decline.

CONCLUSIONS

Add-on therapy with anti-IL-5 in severe eosinophilic asthma was associated with an attenuated FEV₁ decline. The causality of this observation should, however, be confirmed in future prospective controlled studies.

Parenchymal destruction in asthma: Fixed airflow obstruction and lung function trajectory

BACKGROUND

Fixed airflow obstruction (FAO) in asthma, particularly in nonsmokers, is generally believed to be caused by airway remodeling. However, parenchymal destruction may also contribute to FAO and longitudinal decline in forced expiratory volume in 1 second (FEV₁).

OBJECTIVES

To evaluate parenchymal destruction, we used emphysema indices, exponent D, and low-attenuation area percentage (LAA%) on computed tomography (CT), and test whether the parenchymal destruction and airway disease are independently associated with FAO and FEV₁ decline in both smoking and nonsmoking asthma.

METHODS

Exponent D, LAA%, wall area percentage at segmental airways, and airway fractal dimension (AFD) in those with asthma were measured on inspiratory CT and compared to those in patients with chronic obstructive pulmonary disease (COPD).

RESULTS

Exponent D was lower and LAA% was higher in COPD (n = 42) and asthma with FAO (n = 101) than in asthma without FAO (n = 88). The decreased exponent D and increased LAA% were associated with FAO regardless of smoking status or asthma severity. In multivariable analysis, decreased exponent D and increased LAA% were associated with an increased odds ratio of FAO and decreased FEV₁, irrespective of wall area percentage and airway fractal dimension. Moreover, decreased exponent D affected the longitudinal decline in FEV₁ in those with severe asthma, independent of smoking status.

CONCLUSIONS

Patients with asthma with FAO showed parenchymal destruction regardless of smoking status and asthma severity. Parenchymal destruction was associated with an accelerated FEV₁ decline, suggesting the involvements of both airway and parenchyma in the pathophysiology of a subgroup of asthma.

Mixed Sputum Granulocyte Longitudinal Impact on Lung Function in the Severe Asthma Research Program

Rationale: Some reports indicate longitudinal variability in sputum differential cell counts, whereas others describe stability. Highly variable sputum eosinophil percentages are associated with greater lung function loss than persistently elevated eosinophil percentages, but elevated neutrophils are linked to more severe asthma.Objectives: To examine sputum granulocyte stability or variability longitudinally and associations with important clinical characteristics.Methods: The SARP III (Severe Asthma Research Program III) cohort underwent comprehensive phenotype characterization at baseline and annually over 3 years. Adult subjects with acceptable sputum levels were assigned to one of three longitudinal sputum groups: eosinophils predominantly <2%, eosinophils predominantly ≥2%, or highly variable eosinophil percentages (>2 SDs determined from independent, repeated baseline eosinophil percentages). Subjects were similarly assigned to one of three longitudinal neutrophil groups with a 50% cut point.Measurements and Main Results: The group with predominantly <2% sputum eosinophils had the highest lung function (prebronchodilator FEV₁% predicted, P < 0.01; FEV₁/FVC ratio, P < 0.001) at baseline and throughout 3 years compared with other eosinophil groups. Healthcare use did not differ, although the highly variable eosinophil group reported more asthma exacerbations at Year 3. Longitudinal neutrophil groups showed few differences. However, a combination of predominantly ≥2% eosinophil and ≥50% neutrophil groups resulted in the lowest prebronchodilator FEV₁% predicted (P = 0.049) compared with the combination with predominantly <2% eosinophils and<50% neutrophils.Conclusions: Subjects with predominantly ≥2% sputum eosinophils in combination with predominantly ≥50% neutrophils showed greater loss of lung function, whereas those with highly variable sputum eosinophils had greater healthcare use.

Responsiveness to Parenteral Corticosteroids and Lung Function Trajectory in Adults with Moderate-to-Severe Asthma

Rationale: It is unclear why select patients with moderate-to-severe asthma continue to lose lung function despite therapy. We hypothesized that participants with the smallest responses to parenteral corticosteroids have the greatest risk of undergoing a severe decline in lung function.Objectives: To evaluate corticosteroid-response phenotypes as longitudinal predictors of lung decline.Methods: Adults within the NHLBI SARP III (Severe Asthma Research Program III) who had undergone a course of intramuscular triamcinolone at baseline and at ≥2 annual follow-up visits were evaluated. Longitudinal slopes were calculated for each participant's post-bronchodilator FEV₁% predicted. Categories of participant FEV₁ slope were defined: severe decline, >2% loss/yr; mild decline, >0.5-2.0% loss/yr; no change, 0.5% loss/yr to <1% gain/yr; and improvement, ≥1% gain/yr. Regression models were used to develop predictors of severe decline.Measurements and Main Results: Of 396 participants, 78 had severe decline, 91 had mild decline, 114 had no change, and 113 showed improvement. The triamcinolone-induced difference in the post-bronchodilator FEV₁% predicted (derived by baseline subtraction) was related to the 4-year change in lung function or slope category in univariable models (P < 0.001). For each 5% decrement in the triamcinolone-induced difference the FEV1% predicted, there was a 50% increase in the odds of being in the severe decline group (odds ratio, 1.5; 95% confidence interval, 1.3-1.8), when adjusted for baseline FEV₁, exacerbation history, blood eosinophils and body mass index.Conclusions: Failure to improve the post-bronchodilator FEV₁ after a challenge with parenteral corticosteroids is an evoked biomarker for patients at risk for a severe decline in lung function.

Sputum processing by mechanical dissociation: A rapid alternative to traditional sputum assessment approaches

BACKGROUND

Sputum cytology is currently the gold standard to evaluate cellular inflammation in the airways and phenotyping patients with airways diseases. Sputum eosinophil proportions have been used to guide treatment for moderate to severe asthma. Furthermore, raised sputum neutrophils are associated with poor disease control and impaired lung function in both asthma and COPD and small airways disease in cystic fibrosis. However, induced-sputum analysis is subjective and resource heavy, requiring dedicated specialist processing and assessment; this limits its utility in most clinical settings. Indirect blood eosinophil measures have been adopted in clinical care. However, there are currently no good peripheral blood biomarkers of airway neutrophils. A resource-light sputum processing approach could thus help integrate induced sputum more readily into routine clinical care. New mechanical disruption (MD) methods can rapidly obtain viable single cell suspensions from sputum samples.

AIMS

The aim of this study was to compare MD sputum processing to traditional methods for cell viability, granulocyte proportions and sputum cytokine analysis.

METHODS

Sputum plugs were split and processed using traditional methods and the MD method, and samples were then compared.

RESULTS

The MD method produced a homogeneous cell suspension in 62 s; 70 min faster than the standard method used. No significant difference was seen between the cell viability (p = 0.09), or the concentration of eosinophils (p = 0.83), neutrophils (p = 0.99) or interleukin-8 (p = 0.86) using MD.

CONCLUSION

This cost-effective method of sputum processing could provide a more pragmatic, sustainable means of directly monitoring the airway milieu. Therefore, we recommend this method be taken forward for further investigation.

Clinical evaluation of type 2 disease status in a real-world population of difficult to manage asthma using historic electronic healthcare records of blood eosinophil counts

BACKGROUND

Blood eosinophil measurement is essential for the phenotypic characterization of patients with difficult asthma and in determining eligibility for anti-IL-5/IL-5Rα biological therapies. However, assessing such measures over limited time spans may not reveal the true underlying eosinophilic phenotype, as treatment, including daily oral corticosteroid therapy, suppresses eosinophilic inflammation and asthma is intrinsically variable.

METHODS

We interrogated the electronic healthcare records of patients in the Wessex AsThma CoHort of difficult asthma (WATCH) study (UK). In 501 patients being evaluated in this tertiary care centre for difficult to control asthma, all requested full blood count test results in a 10-year retrospective period from the index WATCH assessment were investigated (n = 11,176).

RESULTS

In 235 biological therapy-naïve participants who had 10 or more measures in this time period, 40.3% were eosinophilic (blood eosinophils ≥300 cells/µl) at WATCH enrolment whilst an additional 43.1%, though not eosinophilic at enrolment, demonstrated eosinophilia at least once in the preceding decade. Persistent eosinophilia was associated with worse post-bronchodilator airway obstruction and higher Fractional exhaled Nitric Oxide (FeNO). In contrast, the 16.6% of patients who never demonstrated eosinophilia at this blood eosinophil threshold showed preserved lung function and lower markers of Type 2 inflammation.

CONCLUSIONS

This highlights the central role that type 2 inflammation, as indicated by blood eosinophilia, has in difficult asthma and suggests that longitudinal electronic healthcare record analysis can be an important tool in clinical asthma phenotyping, providing insight that may help understand disease progression and better guide more specific treatment approaches.

Risk Factors Predicting Severe Asthma Exacerbations in Adult Asthmatics: A Real-World Clinical Evidence

PURPOSE

Minimizing the future risk of asthma exacerbation (AE) is one of the main goals of asthma management. We investigated prognostic factors for risk of severe AE (SAE) in a real-world clinical setting.

METHODS

This is an observational study evaluating subjects who were diagnosed with asthma and treated with anti-asthmatic medications from January 1995 to June 2018. Risk factors for SAE were analyzed in 2 treatment periods (during the initial 2 years and the following 3-10 years of treatment) using the big data of electronic medical records.

RESULTS

In this study, 5,058 adult asthmatics were enrolled; 1,335 (28.64%) experienced ≥ 1 SAE during the initial 2 years of treatment. Female sex, higher peripheral eosinophil/basophil counts, and lower levels of forced expiratory volume in 1 second (FEV1; %) were factors predicting the risk of SAEs (P < 0.001 for all). Higher serum total immunoglobulin E levels increased the risk of SAEs among the patients having ≤ 2 SAEs (P = 0.025). Patients with more frequent SAEs during the initial 2 years of treatment had significantly higher risks of SAEs during the following years of treatment (P < 0.001, for all) (patients with ≥ 4 SAEs, odds ratio [OR], 29.147; those with 3 SAEs, OR, 14.819; those with 2 SAEs, OR, 9.867; those with 1 SAE, OR, 5.116), had higher maintenance doses of systemic steroids, and showed more gradual decline in FEV1 (%) and FEV1/forced vital capacity levels maintained during the following years of treatment (P < 0.001 for all).

CONCLUSIONS

Asthmatics having risk factors for SAEs (female sex, higher peripheral eosinophil/basophil counts, and lower FEV1) should be strictly monitored to prevent future risk and improve clinical outcomes.

Blood Eosinophil Count as a Predictor of Lung Function Decline in Healthy Individuals

BACKGROUND

Little is known about the effect of blood eosinophil count (BEC) on a decline in lung function in healthy individuals.

OBJECTIVE

Using a well-established health screening database, we assessed the associations between BEC and a decline in lung function, measured as the forced expiratory volume in 1 second (FEV₁).

METHODS

Serial BEC and FEV₁ data were analyzed using linear mixed models adjusted for gender, height, and smoking status. The association between BEC consistency and a decline in FEV₁ was evaluated in subpopulation analyses.

RESULTS

A total of 4634 individuals were enrolled. The mean number of health screenings was 7.49 over an average of 11.74 years of observation. A higher log2-transformed BEC was significantly associated with a greater decline in FEV₁ that was stronger in nonsmokers (P = 8.56 × 10^-8) than in smokers (P = 1.52 × 10^-3). In subpopulation analyses of 2018 individuals with consistent BECs, those with BECs consistently ≥100/μL (P = 4.58 × 10^-6), ≥200/μL (P = 3.53 × 10^-7), and ≥300/μL (P = 1.12 × 10^-3) had a significantly higher dose-dependent FEV₁ decline than those with BECs consistently <100/μL. A BEC threshold of 100/μL in nonsmokers and 200/μL in smokers may predict an accelerated decline in FEV₁.

CONCLUSIONS

BEC is associated with a decline in FEV₁, and a consistently high BEC is an independent risk factor for an accelerated decline in FEV₁. These results suggest the use of the BEC to identify healthy individuals at high risk for developing chronic lung disease, which in turn may enable a tailored preventive strategy.

FEV1 decline in relation to blood eosinophils and neutrophils in a population-based asthma cohort

Background

The relationship between lung function decline and eosinophils and neutrophils has important therapeutic implications among asthmatics, but it has rarely been studied in large cohort studies.

Objective

The aim is to study the relationship between blood eosinophils and neutrophils and FEV₁ decline in a long-term follow-up of a population-based adult asthma cohort.

Methods

In 2012–2014, an adult asthma cohort was invited to a follow-up including spirometry, blood sampling, and structured interviews, and n = 892 participated (55% women, mean age 59 y, 32–92 y). Blood eosinophils, neutrophils and FEV ₁ decline were analyzed both as continuous variables and divided into categories with different cut-offs. Regression models adjusted for smoking, exposure to vapors, gas, dust, or fumes (VGDF), use of inhaled and oral corticosteroids, and other possible confounders were utilized to analyze the relationship between eosinophils and neutrophils at follow-up and FEV₁ decline.

Results

The mean follow-up time was 18 years, and the mean FEV ₁ decline was 27 ml/year. The annual FEV₁ decline was related to higher levels of both blood eosinophils and neutrophils at follow-up, but only the association with eosinophils remained when adjusted for confounders. Further, the association between FEV₁ decline and eosinophils was stronger among those using ICS. With EOS <0.3 × 10⁹/L as reference, a more rapid decline in FEV1 was independently related to EOS ≥0.4 × 10⁹/L in adjusted analyses.

Conclusions and clinical relevance

Besides emphasizing the importance of smoking cessation and reduction of other harmful exposures, our real-world results indicate that there is an independent relationship between blood eosinophils and FEV₁ decline among adults with asthma.

Risk factors for fixed airflow obstruction in children and adolescents with asthma: 4-Year follow-up

BACKGROUND

Asthma is a disease with reversible bronchoconstriction; however, some patients develop fixed airflow obstruction (FAO). Previous studies have reported the incidence and risk factors of FAO in adults; however, the corresponding factors in children remain poorly understood.

AIM

To evaluate the incidence and risk factors of FAO in children and adolescents with asthma.

METHOD

Observational and prospective cohort study with a 4-year follow-up of clinically stable patients with asthma (from 6-8 years old). Anthropometric data, history of asthma, number of hospitalizations, frequent exacerbations, asthma severity, asthma control, inhaled corticosteroid dose, atopy, and lung function were analyzed as potential risk factors for FAO. FAO was defined by a ratio of the forced expiratory volume in the first second to the forced vital capacity below the lower limit of normal, even after inhaled and oral corticosteroid treatment.

RESULTS

Four hundred and twenty-eight patients were recruited, and 358 were analyzed. The FAO incidence in children and adolescents with asthma was 9.5% (n = 34), starting at 10 years of age. Age, body mass index, hospitalizations for asthma, bronchodilator response, frequent exacerbations, length of exacerbations, and asthma severity were associated with FAO. Frequent exacerbations (odds ratio [OR] = 4.0; 95% confidence interval [CI] = 1.3-11.7) and asthma severity categorized as steps 4 to 5 (OR = 3.5; 95% CI = 1.6-7.6) remained risk factors.

CONCLUSIONS

Frequent exacerbations and asthma severity are the risk factors for FAO in children and adolescents with asthma.

Practical Approach to Children Presenting with Eosinophila and Hypereosinophilia

Eosinophilia is not a rare finding in clinical practice, and often poses problems in terms of etiologic research and differential diagnosis. Peripheral eosinophilia is defined by a blood eosinophil count > 500 cells/μL. It is classified into mild (500-1500 cells/μl), moderate (1500-5000 cells/μl) and severe for an eosinophil count > 5000 cells /μl. The term "hypereosinophilia" defines a condition characterized by a blood eosinophil count >1500 cells/μl in at least two consecutive tests made with a minimum of a 4-week interval. The causes of eosinophilia are various, and can be summarized by the acronym "APLV" which refers to Allergic disorders, Parasitic infections, Leukemia/ Lymphomas (and solid tumors) and Vasculitis-Immunodeficiency diseases, with allergic disorders and parasitic infections representing the most commonly identified causes. Allergic disorders are usually associated with mild eosinophilia, whereas values >20.000 cell/μl are highly suggestive for myeloproliferative disorders. Eosinophils may also be directly responsible for organ damage, mainly at cardiac, pulmonary and cutaneous level, deriving from the release of the granule products, of lipidic mediators and cytokines. Therefore, in the physician's approach to a patient with persistent hypereosinophilia, it is also important to investigate the presence of organ involvement. In this review, we propose a diagnostic algorithm for children presenting with either blood eosinophilia or hypereosinophilia. This algorithm focuses on the patient's history and clinical manifestations as the first step and the level and persistence of blood eosinophilia as the second, and this can help the physician to identify patients presenting with an elevated blood eosinophil count that need further laboratory or instrumental investigations.

Effect of omalizumab on lung function and eosinophil levels in adolescents with moderate-to-severe allergic asthma

BACKGROUND

Omalizumab improves clinical outcomes in patients with asthma. Several studies have shown lung function improvements with omalizumab; however, this has not been examined exclusively in adolescents.

OBJECTIVE

To assess the effect of omalizumab on lung function and eosinophil counts in adolescents with uncontrolled moderate-to-severe allergic asthma.

METHODS

In this post hoc analysis, data from adolescents aged 12 to 17 years from 8 randomized trials of omalizumab were pooled (studies 008, 009, and 011, and SOLAR, INNOVATE, ALTO, ETOPA, and EXTRA). Changes from baseline to end of study in forced expiratory volume in 1 second (FEV₁), percent predicted FEV₁ (ppFEV₁), forced vital capacity (FVC), and blood eosinophil counts were assessed by fitting an analysis of covariance model and calculating least squares mean (LSM) difference for omalizumab vs placebo.

RESULTS

A total of 340 adolescents were identified (omalizumab, n = 203 [59.7%]; placebo, n = 137 [40.3%]). Omalizumab increased all baseline lung function variables more than placebo by end of study: LSM treatment differences (95% confidence interval) were 3.0% (0.2%-5.7%; P = .035), 120.9 mL (30.6-211.2 mL; P = .009), and 101.5 mL (8.3-194.6 mL; P = .033) for ppFEV₁, absolute FEV₁, and FVC, respectively. The LSM difference demonstrated a greater reduction in eosinophil counts for omalizumab vs placebo: -85.9 cells/μL (-137.1 to -34.6 cells/μL; P = .001).

CONCLUSION

Omalizumab was associated with lung function improvements and circulating eosinophil counts reductions in adolescents with moderate-to-severe uncontrolled asthma. Findings emphasize the effect of omalizumab in young patients and the need to optimize treatment early in the disease course. https://clinicaltrials.gov/: NCT00314574, NCT00046748, NCT00401596.

The equine asthma model of airway remodeling: from a veterinary to a human perspective

Human asthma is a complex and heterogeneous disorder characterized by chronic inflammation, bronchospasm and airway remodeling. The latter is a major determinant of the structure-function relationship of the respiratory system and likely contributes to the progressive and accelerated decline in lung function observed in patients over time. Corticosteroids are the cornerstone of asthma treatment. While their action on inflammation and lung function is well characterized, their effect on remodeling remains largely unknown. An important hindrance to the study of airway remodeling as a major focus in asthma research is the lack of reliable non-invasive biomarkers. In consequence, the physiologic and clinical consequences of airway wall thickening and altered composition are not well understood. In this perspective, equine asthma provides a unique and ethical (non-terminal) preclinical model for hypothesis testing and generation. Severe equine asthma is a spontaneous disease affecting adult horses characterized by recurrent and reversible episodes of disease exacerbations. It is associated with bronchoalveolar neutrophilic inflammation, bronchospasm, and excessive mucus secretion. Severe equine asthma is also characterized by bronchial remodeling, which is only partially improved by prolonged period of disease remission induced by therapy or antigen avoidance strategies. This review will focus on the similarities and differences of airway remodeling in equine and human asthma, on the strengths and limitations of the equine model, and on the challenges the model has to face to keep up with human asthma research.

Protocol for the Wessex AsThma CoHort of difficult asthma (WATCH): a pragmatic real-life longitudinal study of difficult asthma in the clinic

Background

Asthma is now widely recognised to be a heterogeneous disease. The last two decades have seen the identification of a number of biological targets and development of various novel therapies. Despite this, asthma still represents a significant health and economic burden worldwide. Why some individuals should continue to suffer remains unclear.

Methods

The Wessex Asthma Cohort of Difficult Asthma (WATCH) is an ongoing ‘real-life’, prospective study of patients in the University Hospital Southampton Foundation Trust (UHSFT) Difficult Asthma service. Research data capture is aligned with the extensive clinical characterisation required of a commissioned National Health Service (NHS) Specialist Centre for Severe Asthma. Data acquisition includes detailed clinical, health and disease-related questionnaires, anthropometry, allergy and lung function testing, radiological imaging (in a small subset) and collection of biological samples (blood, urine and sputum). Prospective data are captured in parallel to clinical follow up appointments, with data entered into a bespoke database.

Discussion

The pragmatic ongoing nature of the WATCH study allows comprehensive assessment of the real world clinical spectrum seen in a Specialist Asthma Centre and allows a longitudinal perspective of deeply phenotyped patients. It is anticipated that the WATCH cohort would act as a vehicle for potential collaborative asthma studies and will build upon our understanding of mechanisms underlying difficult asthma.

Electronic supplementary material

The online version of this article (10.1186/s12890-019-0862-2) contains supplementary material, which is available to authorized users.

Increase in blood eosinophils during follow-up is associated with lung function decline in adult asthma

BACKGROUND

Asthma is associated with accelerated rate of lung function (FEV₁) decline.

OBJECTIVE

To determine predictive factors associated with FEV₁ decline in adult asthma.

METHODS

A retrospective study was conducted in 229 asthmatics recruited from the University Asthma Clinic of Liege. Subjects had at least two visits with post-bronchodilation (post-BD) FEV₁ and minimum one year between them. A multivariable linear regression analysis was conducted in order to come up with factors associated with lung function decline.

RESULTS

Post-BD FEV₁ decline in % predicted. y^-1 was 0.2 (95%CI -2.0 to 2.8) in the overall population. Our population was made up of mild to moderate asthmatics [1] for 58%, aged 50 (41-60) years old, 62% were female and 59% were atopic. Median ICS dose was 1000 μg beclomethasone equivalent (CFC)/day with 81% treated at baseline. Time between visits was 46.8 ± 32.1 months. The univariate linear regression analysis revealed a negative association between % predicted FEV₁ decline and baseline ACQ (p < 0.0001) and blood eosinophils (% and/mm³) (p < 0.0001 and p < 0.0001). A positive association was found between % predicted FEV₁ decline and baseline pre-BD FEV1 (mL) values (p = 0.001), blood neutrophils (%) (p = 0.02), change in blood eosinophils (%) (p < 0.0001), time between visits (months) (p < 0.0001). The predictive variables for accelerated decline highlighted by the multivariable analysis (r² = 0.39) were change in blood eosinophils (%) over time (p = 0.002) and time between visits (months) (p < 0.0001).

CONCLUSION

These findings highlight a new value for blood eosinophil counts as their increase over time predicts greater lung function decline in asthma.

Future Risks in Patients With Severe Asthma

A major burden of severe asthma is the future risk of adverse health outcomes. Patients with severe asthma are prone to serious exacerbation and deterioration of lung function and may experience side effects of medications such as oral corticosteroids (OCSs). However, such future risk is not easily measurable in daily clinical practice. In particular, currently available tools to measure asthma control and asthma-related quality of life incompletely predict the future risk of medication-related morbidity. This is a significant issue in asthma management. This review summarizes the current evidence of future risk in patients with severe asthma. As future risk is poorly perceived by controlled asthmatics, our review focuses on the risk in patients with ‘controlled’ severe asthma. Of note, it is likely that long-term OCS therapy may not prevent future asthma progression, including lung function decline. In addition, the risk of drug side effects increases even during low-dose OCS therapy. Thus, novel treatments are highly desirable for reducing future risks without any loss of asthma control.

Associations between blood eosinophils and decline in lung function among adults with and without asthma

Eosinophilic inflammation and airway remodelling are characteristic features of asthma, but the association between them is unclear. We assessed associations between blood eosinophils and lung function decline in a population-based cohort of young adults.We used linear mixed models to analyse associations between blood eosinophils and spirometry at 21, 26, 32 and 38 years adjusting for sex, smoking, asthma and spirometry at age 18 years. We further analysed associations between mean eosinophil counts and changes in spirometry from ages 21 to 38 years.Higher eosinophils were associated with lower forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ratios and lower FEV₁ % predicted values for both pre- and post-bronchodilator spirometry (all p-values ≤0.048). Although eosinophil counts were higher in participants with asthma, the associations between eosinophils and spirometry were similar among participants without asthma or wheeze. Participants with mean eosinophil counts >0.4×10⁹ cells·L^-1 between 21 and 38 years had greater declines in FEV₁/FVC ratios (difference 1.8%, 95% CI 0.7-2.9%; p=0.001) and FEV₁ values (difference 3.4% pred, 95% CI 1.5-5.4% pred); p=0.001) than those with lower counts.Blood eosinophils are associated with airflow obstruction and enhanced decline in lung function, independently of asthma and smoking. Eosinophilia is a risk factor for airflow obstruction even in those without symptoms.

Role of sputum biomarkers in the management of asthma

PURPOSE OF REVIEW

Airway inflammation is considered to be a cardinal feature of asthma. However, the type of airway inflammation is heterogeneous and airway inflammation may even be absent. Biomarkers may help to identify the inflammatory phenotype or endotype, especially now the time has come that targeted therapies enter daily practice.

RECENT FINDINGS

Sputum biomarkers have increased our insights into the different inflammatory asthma phenotypes, their response to treatment and their association with progression of disease. New endotypes of type 2 driven inflammation were identified using a multidimensional approach. A specific mast cell subtype has been linked with type 2 driven inflammation and response to inhaled corticosteroids. Advances have been made with regard to sputum cytokine analysis and might also help to guide future treatment of severe asthma.

SUMMARY

Identifying the target population for biological therapies will not be possible without the use of biomarkers. Optimized, easy-to-apply, automated methods for sputum analysis (cellular content or soluble markers) need to be developed for implementation of sputum biomarkers in daily clinical practice.

Asthma Exacerbations Associated with Lung Function Decline in Patients with Severe Eosinophilic Asthma

BACKGROUND

Limited data describe the association between the frequency of asthma exacerbations and the decline in lung function in severe asthma.

OBJECTIVE

To determine whether asthma exacerbations are associated with enhanced decline in lung function.

METHODS

Changes in lung function were analyzed retrospectively using data from the DREAM and MENSA studies of mepolizumab intervention in patients with severe asthma. Patients were either nonsmokers or former smokers. A linear regression model was used to analyze the relationship between the number of exacerbations and decline in FEV₁ across treatment groups.

RESULTS

In a combined post hoc analysis, 57% (n = 572) of patients had no exacerbations and experienced an improvement in postbronchodilator FEV₁ of 143 mL. In contrast, in patients who experienced 3 or more exacerbations, there was a decrease in postbronchodilator FEV₁ of 77 mL in the combined analysis. The linear modeling analysis estimated that for each exacerbation seen during the observational period, there was a decrease of 50 mL in FEV₁ (P < .001).

CONCLUSIONS

A direct relationship between the number of exacerbations in patients with severe eosinophilic asthma and decline in lung function was observed. Repeated exacerbations may be associated with accelerated loss of lung function.

Lung Function Trajectory Types in Never-Smoking Adults With Asthma: Clinical Features and Inflammatory Patterns

Purpose

Asthma is a heterogeneous disease that responds to medications to varying degrees. Cluster analyses have identified several phenotypes and variables related to fixed airway obstruction; however, few longitudinal studies of lung function have been performed on adult asthmatics. We investigated clinical, demographic, and inflammatory factors related to persistent airflow limitation based on lung function trajectories over 1 year.

Methods

Serial post-bronchodilator forced expiratory volume (FEV) 1% values were obtained from 1,679 asthmatics who were followed up every 3 months for 1 year. First, a hierarchical cluster analysis was performed using Ward's method to generate a dendrogram for the optimum number of clusters using the complete post-FEV1 sets from 448 subjects. Then, a trajectory cluster analysis of serial post-FEV1 sets was performed using the k-means clustering for the longitudinal data trajectory method. Next, trajectory clustering for the serial post-FEV1 sets of a total of 1,679 asthmatics was performed after imputation of missing post-FEV1 values using regression methods.

Results

Trajectories 1 and 2 were associated with normal lung function during the study period, and trajectory 3 was associated with a reversal to normal of the moderately decreased baseline FEV1 within 3 months. Trajectories 4 and 5 were associated with severe asthma with a marked reduction in baseline FEV1. However, the FEV1 associated with trajectory 4 was increased at 3 months, whereas the FEV1 associated with trajectory 5 was persistently disturbed over 1 year. Compared with trajectory 4, trajectory 5 was associated with older asthmatics with less atopy, a lower immunoglobulin E (IgE) level, sputum neutrophilia and higher dosages of oral steroids. In contrast, trajectory 4 was associated with higher sputum and blood eosinophil counts and more frequent exacerbations.

Conclusions

Trajectory clustering analysis of FEV1 identified 5 distinct types, representing well-preserved to severely decreased FEV1. Persistent airflow obstruction may be related to non-atopy, a low IgE level, and older age accompanied by neutrophilic inflammation and low baseline FEV1 levels.

The clinical role of fractional exhaled nitric oxide in asthma control

BACKGROUND

The potential role and characteristics of fractional exhaled nitric oxide (FeNO) remain unclear in the treatment of asthma.

OBJECTIVE

To explore the clinical role of FeNO in asthmatic treatment.

METHODS

We evaluated whether the mean or change of FeNO levels in the treatment period is associated with other conventional control parameters and predicted some clinical outcomes of asthma. We retrospectively analyzed the mean and percentage change of FeNO levels in the first 5 measurements at our hospital.

RESULTS

The study found a significantly strong correlation between FeNO level at diagnosis and the largest changes of FeNO values from diagnosis. No significant correlations were observed between FeNO levels and other parameters (Asthma Control Test [ACT] score or forced expiratory volume in one second [FEV₁]) in mean and percentage change of values under treatment of asthma; however, significant positive correlations were found between ACT scores and FEV₁. The mean FeNO level revealed a significant negative correlation with an annual change in FEV₁ in individuals with asthma who were followed up for more than 2 years. Both the mean ACT score and percent predicted FEV₁ revealed a significant negative correlation with occasional use of systemic corticosteroids.

CONCLUSION

During conventional treatment of asthma, the largest changes of FeNO values from diagnosis were strongly correlated with FeNO levels at diagnosis. As for the unlikely conventional parameters, no significant associations were observed between FeNO levels and deterioration of asthma during the treatment periods. An elevated mean FeNO level may be a marker of decreased lung function in individuals with asthma.

Airway basophils are increased and activated in eosinophilic asthma

BACKGROUND

The impact of basophils on asthma pathogenesis remains largely unexplored, particularly in humans. Here, we evaluated the frequencies and activation status of basophils in the sputum of adult asthmatic patients and related our findings to other parameters of eosinophilic airway inflammation.

METHODS

We enrolled 44 adult asthmatic patients who were being treated with inhaled corticosteroids (ICS). Analysis of the induced sputum, exhaled nitric oxide fraction (FeNO) measurement, and asthma control test (ACT) were carried out together with standard blood and pulmonary function tests. The cellular composition of the sputum was examined by flow cytometry, and the phenotypes of blood and sputum basophils were compared.

RESULTS

Basophils were increased in the sputum of asthmatic patients. The expression of CD203c on sputum basophils was significantly higher than that on blood basophils. The percentage of sputum basophils was positively correlated with those of eosinophils and mast cells; it was also correlated with that of blood eosinophils and FeNO. However, sputum basophils were not correlated with serum IgE, lung function, or the percentage of blood basophils. A receiver-operating characteristic (ROC) curve showed the superiority of sputum basophils as a surrogate marker of the percentages of sputum eosinophils compared with absolute numbers of blood eosinophils and FeNO.

CONCLUSION

The number of activated basophils was increased in the sputum of patients with eosinophilic asthma and correlated with airway and blood eosinophils. Our observations suggest that sputum basophils may serve as a biomarker to monitor new therapeutic approaches for the treatment of eosinophilic asthma.

Proteomic analysis of sputum reveals novel biomarkers for various presentations of asthma

BACKGROUND

It is now recognized that asthma can present in different forms. Typically, asthma present with symptoms of wheeze, breathlessness and cough. Atypical forms of asthma such as cough variant asthma (CVA) or chest tightness variant asthma (CTVA) do not wheeze. We hypothesize that these different forms of asthma may have distinctive cellular and molecular features.

METHODS

30 patients with typical or classical asthma (CA), 27 patients with CVA, 30 patients with CTVA, and 30 healthy control adults were enrolled in this prospective study. We measured serum IgE, lung function, sputum eosinophils, nitric oxide in exhaled breath (FeNO). We performed proteomic analysis of induced-sputum supernatants by mass spectrometry.

RESULTS

There were no significant differences in atopy and FEV₁ among patients with CA, CVA, and CTVA. Serum IgE, sputum eosinophil percentages, FeNO, anxiety and depression scores were significantly increased in the three presentations of asthmatic patients as compared with healthy controls but there was no difference between the asthmatic groups. Comprehensive mass spectrometric analysis revealed more than a thousand proteins in the sputum from patients with CA, CVA, and CTVA, among which 23 secreted proteins were higher in patients than that in controls.

CONCLUSIONS

Patients with CA, CVA, or CTVA share common clinical characteristics of eosinophilic airway inflammation. And more importantly, their sputum samples were composed with common factors with minor distinctions. These findings support the concept that these three different presentations of asthma have similar pathogenetic mechanism in terms of an enhanced Th2 associated with eosinophilia. In addition, this study identified a pool of novel biomarkers for diagnosis of asthma and to label its subtypes. Trial registration http://www.chictr.org.cn (ChiCTR-OOC-15006221).

Oral Glucocorticoid-Sparing Effect of Benralizumab in Severe Asthma

BACKGROUND

Many patients with severe asthma rely on oral glucocorticoids to manage their disease. We investigated whether benralizumab, a monoclonal antibody directed against the alpha subunit of the interleukin-5 receptor that significantly reduces the incidence of asthma exacerbations, was also effective as an oral glucocorticoid-sparing therapy in patients relying on oral glucocorticoids to manage severe asthma associated with eosinophilia.

METHODS

In a 28-week randomized, controlled trial, we assessed the effects of benralizumab (at a dose of 30 mg administered subcutaneously either every 4 weeks or every 8 weeks [with the first three doses administered every 4 weeks]) versus placebo on the reduction in the oral glucocorticoid dose while asthma control was maintained in adult patients with severe asthma. The primary end point was the percentage change in the oral glucocorticoid dose from baseline to week 28. Annual asthma exacerbation rates, lung function, symptoms, and safety were assessed.

RESULTS

Of 369 patients enrolled, 220 underwent randomization and started receiving benralizumab or placebo. The two benralizumab dosing regimens significantly reduced the median final oral glucocorticoid doses from baseline by 75%, as compared with a reduction of 25% in the oral glucocorticoid doses in the placebo group (P<0.001 for both comparisons). The odds of a reduction in the oral glucocorticoid dose were more than 4 times as high with benralizumab as with placebo. Among the secondary outcomes, benralizumab administered every 4 weeks resulted in an annual exacerbation rate that was 55% lower than the rate with placebo (marginal rate, 0.83 vs. 1.83, P=0.003), and benralizumab administered every 8 weeks resulted in an annual exacerbation rate that was 70% lower than the rate with placebo (marginal rate, 0.54 vs. 1.83, P<0.001). At 28 weeks, there was no significant effect of either benralizumab regimen on the forced expiratory volume in 1 second (FEV₁), as compared with placebo. The effects on various measures of asthma symptoms were mixed, with some showing significant changes in favor of benralizumab and others not showing significant changes. Frequencies of adverse events were similar between each benralizumab group and the placebo group.

CONCLUSIONS

Benralizumab showed significant, clinically relevant benefits, as compared with placebo, on oral glucocorticoid use and exacerbation rates. These effects occurred without a sustained effect on the FEV₁. (Funded by AstraZeneca; ZONDA ClinicalTrials.gov number, NCT02075255 .).

Sputum cell counts to manage prednisone-dependent asthma: effects on FEV1 and eosinophilic exacerbations

Background

Prednisone dependence in asthma is usually described based on clinical and spirometric characteristics. It is generally believed that these patients have frequent exacerbations and lose lung function rapidly because of uncontrolled airway eosinophilia.

Objectives

The objectives of this study are to report the effect on asthma exacerbations and the change in lung function over time in prednisone-dependent asthma when severe asthma is managed using a protocol that aims to maintain normal sputum cell counts.

Methods

A retrospective survey of patients prospectively assessed in a university tertiary care asthma clinic.

Results

52 patients (30 males, mean age 51 years, 64% non-atopic) were followed for a median period of 5.4 years (min–max: 0.2–35.2). Monitoring with the aim of keeping sputum eosinophils below 3% resulted in higher doses of corticosteroids (median daily dose of prednisone was 10 mg and for inhaled corticosteroids was 1500 μg of fluticasone equivalent) than at baseline and this was associated with predictable adverse effects. Despite the disease severity, 10 patients (19%) did not require LABA for symptom control. Most importantly, over the period of follow-up, there were only 0.3 eosinophilic exacerbations/patient/year. Overall, there was an increase in FEV1 over the period of follow-up (mean +84.6 ml/year) rather than an expected decline.

Conclusions

Monitoring of eosinophils in sputum enables to maintain symptom control and preserve FEV1 in patients with severe prednisone-dependent asthma.

Long-term Efficacy and Safety of Mepolizumab in Patients With Severe Eosinophilic Asthma: A Multi-center, Open-label, Phase IIIb Study

PURPOSE

Patients with severe eosinophilic asthma often experience recurrent asthma exacerbations despite intensive inhaled corticosteroid therapy. In 2 previous double-blind studies (MENSA [NCT01691521] and SIRIUS [NCT01691508]), treatment with intravenous or subcutaneous mepolizumab was associated with significantly reduced annualized exacerbation rates and oral corticosteroid (OCS) requirements compared with placebo. The purpose of this study was to assess the long-term safety and efficacy of subcutaneous mepolizumab treatment in patients with severe eosinophilic asthma.

METHODS

COSMOS was a 52-week, open-label extension study in patients who received mepolizumab or placebo in MENSA or SIRIUS. Patients received subcutaneous mepolizumab regardless of prior treatment allocation and continued to receive appropriate standard-of-care asthma therapy throughout. The primary objective was to assess the long-term safety of mepolizumab; end points included adverse events (AEs) and serious AEs (SAEs). Efficacy assessments included the annualized exacerbation rate and durability of response (defined as the exacerbation rate and OCS dose reduction when combined with MENSA and SIRIUS data, respectively).

FINDINGS

In total, 558 (86%; previous mepolizumab: 358; previous placebo: 200) and 94 (14%; previous mepolizumab: 58, previous placebo: 36) patients experienced on-treatment AEs and SAEs, respectively. No fatal AEs were reported. Totals of 13 (2%) and 29 (4%) patients experienced systemic and local site reactions, respectively. There were no reports of mepolizumab-related anaphylaxis. Mepolizumab treatment was shown to exert a durable response, with patients who previously received mepolizumab in MENSA or SIRIUS maintaining reductions in exacerbation rate and OCS dosing throughout COSMOS. Patients who previously received placebo in MENSA or SIRIUS demonstrated improvements in these end points following treatment with mepolizumab in COSMOS.

IMPLICATIONS

These data demonstrate a favorable safety profile of mepolizumab and indicate a durable and stable effect over time, supporting long-term treatment in patients with severe eosinophilic asthma. ClinicalTrials.gov identifier: NCT01842607.

Serum IL-5 and IL-13 consistently serve as the best predictors for the blood eosinophilia phenotype in adult asthmatics

BACKGROUND

Molecular biomarkers that identify the phenotype of blood eosinophilia were evaluated in adult asthmatics, and their relationship with clinically significant asthma outcomes was assessed. Patients were clustered based on their molecular fingerprint.

METHODS

At inclusion, 64 patients were evaluated for phenotypic traits, sputum and blood eosinophilia, exhaled NO, serum cytokines and chemokines, total serum IgE, lung function (LF), and airway hyper-responsiveness (AHR). Within-patient changes were evaluated in 44 patients 6 weeks later.

RESULTS

Lung function, asthma control, and monocyte chemotactic protein-1 (MCP-1) were identified as the most important distinguisher and blood eosinophilia as second most important identifier in principal component analysis. A robust relationship was observed between blood eosinophilia and IL-5, IL-13, and eosinophil-derived neurotoxin (EDN), which stayed consistent after 6 weeks. Serum IL-5 and IL-13 were the two best, followed by EDN as separators of high vs low blood eosinophilia. Periostin did not identify blood or sputum eosinophilia, even after stratification for total IgE, and did not correlate with IL-5, IL-13, eotaxin, or EDN. IL-5 and IL-13 showed strong correlations with AHR and monocyte chemoattractant protein (MCP)-1 with asthma severity and fast LF decline. The presence of high or low expression of MCP-1, eotaxin, and IL-8 identified two separate blood eosinophilia patient clusters linked to asthma severity.

CONCLUSION

Serum IL-5 and IL-13 are reliable biomarkers for the blood eosinophilia asthma phenotype. High or low expression of MCP-1, eotaxin, and IL-8 discriminates between eosinophilic asthma severity clusters.

Exacerbation risk in severe asthma is stratified by inflammatory phenotype using longitudinal measures of sputum eosinophils

BACKGROUND

Airway inflammatory phenotyping is increasingly applied to subjects with asthma. However, its relationship to clinical outcomes in difficult asthma is incompletely elucidated.

OBJECTIVE

The goal of our study was to determine the relationship between exacerbation rates and phenotypes of difficult asthma based on the longitudinal measures of sputum eosinophils and neutrophils.

METHODS

Subjects in the longitudinal observational study from two tertiary care centres that completed 1 year of observation and provided at least three sputum samples were classified by inflammatory phenotypes using previously established thresholds. Kaplan-Meier curves and univariable and multivariable Cox proportional hazard models were used to determine the association between inflammatory phenotypes and exacerbation rate.

RESULTS

During the study, 115 exacerbations occurred in 73 severe asthmatic subjects. Subjects with the persistently eosinophilic phenotype had a significantly shorter time to first exacerbation and greater risk of exacerbation over a 1-year period than those with the non-eosinophilic phenotype based on the univariable and multivariable Cox proportional hazard model (hazard ratio [HR], 3.24; 95% confidence interval [CI], 1.35-7.72; adjusted HR, 3.90; 95% CI, 1.34-11.36). No significant differences in time to first exacerbation or exacerbation risk over a 1-year period were observed among the neutrophilic phenotypes.

CONCLUSIONS

The persistent eosinophilic phenotype is associated with increased exacerbation risk compared with the non-eosinophilic phenotype in severe asthma. No differences in time to first exacerbation or exacerbation risk over a 1-year period were detected among neutrophilic phenotypes.

Novel approaches to the management of noneosinophilic asthma

Noneosinophilic airway inflammation occurs in approximately 50% of patients with asthma. It is subdivided into neutrophilic or paucigranulocytic inflammation, although the proportion of each subtype is uncertain because of variable cut-off points used to define neutrophilia. This article reviews the evidence for noneosinophilic inflammation being a target for therapy in asthma and assesses clinical trials of licensed drugs, novel small molecules and biologics agents in noneosinophilic inflammation. Current symptoms, rate of exacerbations and decline in lung function are generally less in noneosinophilic asthma than eosinophilic asthma. Noneosinophilic inflammation is associated with corticosteroid insensitivity. Neutrophil activation in the airways and systemic inflammation is reported in neutrophilic asthma. Neutrophilia in asthma may be due to corticosteroids, associated chronic pulmonary infection, altered airway microbiome or delayed neutrophil apoptosis. The cause of poorly controlled noneosinophilic asthma may differ between patients and involve several mechanism including neutrophilic inflammation, T helper 2 (Th2)-low or other subtypes of airway inflammation or corticosteroid insensitivity as well as noninflammatory pathways such as airway hyperreactivity and remodelling. Smoking cessation in asthmatic smokers and removal from exposure to some occupational agents reduces neutrophilic inflammation. Preliminary studies of 'off-label' use of licensed drugs suggest that macrolides show efficacy in nonsmokers with noneosinophilic severe asthma and statins, low-dose theophylline and peroxisome proliferator-activated receptor gamma (PPARγ) agonists may benefit asthmatic smokers with noneosinophilic inflammation. Novel small molecules targeting neutrophilic inflammation, such as chemokine (CXC) receptor 2 (CXCR2) antagonists reduce neutrophils, but do not improve clinical outcomes in studies to date. Inhaled phosphodiesterase (PDE)4 inhibitors, dual PDE3 and PDE4 inhibitors, p38MAPK (mitogen-activated protein kinase) inhibitors, tyrosine kinase inhibitors and PI (phosphoinositide) 3kinase inhibitors are under development and these compounds may be of benefit in noneosinophilic inflammation. The results of clinical trials of biological agents targeting mediators associated with noneosinophilic inflammation, such as interleukin (IL)-17 and tumor necrosis factor (TNF)-α are disappointing. Greater understanding of the mechanisms of noneosinophilic inflammation in asthma should lead to improved therapies.

Health Issues in Hispanic/Latino Youth

This review focuses on obesity, asthma and mental health functioning as salient health issues affecting Hispanic youth. Burden of these conditions and consequences for adult health are also discussed. Hispanic youth are affected by obesity at an early age; the prevalence of obesity among Hispanic children 6-11 years old is twice as high as the prevalence for non-Hispanic White children of the same age, but among 2-5 years old is 4 times higher. Asthma disproportionally affects certain Hispanic groups, notably children of Puerto Rican ancestry, and the comorbidity of asthma and obesity is an emerging health issue. Another area of concern is the scant data on mental health functioning among Hispanic youth. Research on Hispanic youth mental health have reported high rates of depressive symptomatology and high rates of alcohol use among Hispanic adolescents but despite these findings, they have inadequate access to mental health services. This review highlights the need for better data to gain a better understanding of the health status of Hispanic youth and help develop preventive programs that addresses the need of this population. Improving access to health services, in particular mental health services, is also a crucial aspect.

Eosinophilic airway inflammation: role in asthma and chronic obstructive pulmonary disease

The chronic lung diseases, asthma and chronic obstructive pulmonary disease (COPD), are common affecting over 500 million people worldwide and causing substantial morbidity and mortality. Asthma is typically associated with Th2-mediated eosinophilic airway inflammation, in contrast to neutrophilic inflammation observed commonly in COPD. However, there is increasing evidence that the eosinophil might play an important role in 10-40% of patients with COPD. Consistently in both asthma and COPD a sputum eosinophilia is associated with a good response to corticosteroid therapy and tailored strategies aimed to normalize sputum eosinophils reduce exacerbation frequency and severity. Advances in our understanding of the multistep paradigm of eosinophil recruitment to the airway, and the consequence of eosinophilic inflammation, has led to the development of new therapies to target these molecular pathways. In this article we discuss the mechanisms of eosinophilic trafficking, the tools to assess eosinophilic airway inflammation in asthma and COPD during stable disease and exacerbations and review current and novel anti-eosinophilic treatments.

Will nonasthmatic eosinophilic bronchitis develop into chronic airway obstruction?: a prospective, observational study

OBJECTIVE

The long-term prognosis of nonasthmatic eosinophilic bronchitis (NAEB) is still unclear. The aim of this study was to observe the frequency of relapse among patients with NAEB and the likelihood of NAEB developing into chronic airflow obstruction over time.

METHODS

Patients with NAEB were followed for at least 1 year between 2003 and 2013. During this period, we evaluated clinical symptoms, sputum eosinophil count, spirometry, and bronchial hyperresponsiveness. A linear mixed model was adopted to determine the relationship between time and lung function.

RESULTS

A total of 234 patients with NAEB were identified, of whom 141 were followed for > 1 year (median, 4.1 years). Up to 59.6% of patients had a relapse after treatment. Both allergic rhinitis (OR, 4.37; 95% CI, 1.049-18.203; P = .043) and sputum eosinophilia after 4 weeks of treatment with inhaled corticosteroids (OR, 9.493; 95% CI, 2.381-37.850; P = .001) were risk factors for relapse. Among the 141 patients, mild asthma developed in eight (5.7%). During the follow-up period, no progressive decline in FVC, FEV1, and FEV1/FVC were observed (P > .05). Although the proportion of small airway dysfunction (maximum midexpiratory flow [MMEF] < 65%) significantly increased at the last visit in all groups (all P < .05), only the relapse group showed an MMEF decline at the end of follow-up (P < .05) in the linear mixed model.

CONCLUSIONS

More than 50% of patients with NAEB have repeated episodes associated with persistent sputum eosinophilia after treatment and allergic rhinitis. In the current cohort, chronic airway obstruction does not develop despite small airway dysfunction increases over time.

The Complex Type 2 Endotype in Allergy and Asthma: From Laboratory to Bedside

Better management of allergic diseases needs a sharpened understanding of disease heterogeneity and mechanisms in relation to clinically significant outcomes. Phenotypes describing observable clinical and morphologic characteristics and unique responses to treatment have been developed; however, they do not relate to disease mechanisms. Recently, extended heterogeneous and disease-related metabolic, inflammatory, immunological, and remodeling pathways have been described, and reproducible patterns are defined as disease endotypes. An endotype might consist of several intricated mechanisms that cannot be clearly separated into "pure single molecular mechanism" thus being a "complex endotype." The description of an endotype may rely on biomarkers, which can be the signature of a complex underlying pathway or a key molecule associated with or directly playing a role in a particular disease endotype. The Th2 type inflammation can be defined as a complex endotype in asthma and linked to mechanisms of disease development and response to treatment and to disease outcomes such as exacerbations and remodeling. The type 2 complex endotype in allergies and asthma includes innate lymphoid cells, T helper 2 cells, tissue eosinophilia, and IgE production. Currently, emerging endotype-driven strategies in asthma, particularly the development of biologicals that target a single molecular pathway, are being focused for solving individualized clinical problems on disease outcomes. Progress is also being made for endotyping rhinitis, chronic rhinosinusitis, and atopic dermatitis.

Biomarkers and severe asthma: a critical appraisal

Severe asthma (SA) is a clinically and etiologically heterogeneous respiratory disease which affects among 5–10 % of asthmatic patients. Despite high-dose therapy, a large patients percentage is not fully controlled and has a poor quality of life. In this review, we describe the biomarkers actually known in scientific literature and used in clinical practice for SA assessment and management: neutrophils, eosinophils, periostin, fractional exhaled nitric oxide, exhaled breath condensate and galectins. Moreover, we give an overview on clinical and biological features characterizing severe asthma, paying special attention to the potential use of these ones as reliable markers. We finally underline the need to define different biomarkers panels to select patients affected by severe asthma for specific and personalized therapeutic approach.

Management of the patient with eosinophilic asthma: a new era begins

Now that it is generally accepted that asthma is a heterogeneous condition, phenotyping of asthma patients has become a mandatory part of the diagnostic workup of all patients who do not respond satisfactorily to standard therapy with inhaled corticosteroids. Late-onset eosinophilic asthma is currently one of the most well-defined asthma phenotypes and seems to have a different underlying pathobiology to classical childhood-onset, allergic asthma. Patients with this phenotype can be identified in the clinic by typical symptoms (few allergies and dyspnoea on exertion), typical lung function abnormalities (“fixed” airflow obstruction, reduced forced vital capacity and increased residual volume), typical comorbidities (nasal polyposis) and a good response to systemic corticosteroids. The definitive diagnosis is based on evidence of eosinophilia in bronchial biopsies or induced sputum, which can be estimated with reasonable accuracy by eosinophilia in peripheral blood. Until recently, patients with eosinophilic asthma had a very poor quality of life and many suffered from frequent severe exacerbations or were dependent on oral corticosteroids. Now, for the first time, novel biologicals targeting the eosinophil have become available that have been shown to be able to provide full control of this type of refractory asthma, and to become a safe and efficacious substitute for oral corticosteroids.

Late-onset eosinophilic asthma has a distinct clinical and functional profile with treatment implicationshttp://ow.ly/MH7AH