[Concept of remission in severe asthma]

The use of biotherapies has revolutionized the management of severe asthma. Following a review of asthma pathophysiology, which underpins the development of these new molecules, this article discusses the different types of remission in childhood and adult asthma. The possibilities of achieving remission with each biotherapy and the factors that predict remission will then be developed. Finally, we'll discuss the chances of maintaining good control of the disease after discontinuation of biotherapies, as well as their contribution in terms of systemic and local cortisone sparing.

Evidence for 2 clusters among patients with noneosinophilic asthma

BACKGROUND

Although asthma is often seen as an eosinophilic disease associated with atopy, patients with noneosinophilic asthma represent a substantial part of the population with asthma.

OBJECTIVE

To apply an unsupervised clustering method in a cohort of 588 patients with noneosinophilic asthma (sputum eosinophils < 3%) recruited from an asthma clinic of a secondary care center.

METHODS

Our cluster analysis of the whole cohort identified 2 subgroups as cluster 1 (n = 417) and cluster 2 (n = 171).

RESULTS

Cluster 1 comprised a predominantly female group with late disease onset, a low proportion of atopy (24%), and a substantial smoking history (53%). In this cluster, treatment burden was low (<50% of inhaled corticosteroid users); asthma control and quality of life were poor, with median Asthma Control Test, Asthma Control Questionnaire, and Asthma Quality of Life scores of 16, 1.7, and 4.5, respectively, whereas lung function was preserved with a median postbronchodilation forced expiratory volume in 1 second of 93% predicted. Cluster 2 was a predominantly male group, almost exclusively comprising patients with atopy (99%) with early disease onset and a moderate treatment burden (median inhaled corticosteroids dose 800 µg/d equivalent beclomethasone). In cluster 2, asthma was partially controlled, with median Asthma Control Test and Asthma Control Questionnaire scores reaching 18 and 1.3, respectively, and lung function well preserved with a median postbronchodilation of 95% predicted. Although systemic and airway neutrophilic inflammation was the dominant pattern in cluster 1, cluster 2 essentially comprised paucigranulocytic asthma with moderately elevated fraction exhaled nitric oxide.

CONCLUSION

Noneosinophilic asthma splits into 2 clusters distinguishing by disease onset, atopic status, smoking history, systemic and airway inflammation, and disease control and quality of life.

Super-responders to anti-IL-5/anti-IL-5R are characterised by high sputum eosinophil counts at baseline

Several clinical trials have demonstrated that anti-IL-5(R) biologics were able to improve lung function, asthma control and chronic oral corticosteroid exposure and reduce exacerbations among eosinophilic asthmatic patients. However, a certain variability in clinical responses to anti-IL-5(R) biologics was brought to light. Our study aimed at evaluating the role of baseline sputum eosinophils in identifying super-responders to mepolizumab and benralizumab. Our study reinforces the importance to examine sputum eosinophils in patients suffering from severe asthma before starting a biologic as it is associated with the intensity of response to mepolizumab and benralizumab.

Benralizumab in severe eosinophilic asthma in real life: confirmed effectiveness and contrasted effect on sputum eosinophilia versus exhaled nitric oxide fraction - PROMISE

Background

Randomised controlled trials have shown that benralizumab, an anti-interleukin-5 receptor monoclonal antibody, reduces exacerbations and oral corticosteroid dose and improves asthma control and lung function in severe eosinophilic asthma. The aim of this study was to confirm results of randomised controlled trials in real life in a population of 73 patients with severe eosinophilic asthma treated with benralizumab for at least 12 months.

Methods

Patients underwent careful monitoring of asthma exacerbations, exhaled nitric oxide fraction, lung function, asthma control and quality of life questionnaire responses and sputum induction, and gave a blood sample at baseline, after 6 months and then every year.

Results

We found significant reductions in exacerbations (by 92%, p<0.0001) and oral corticosteroid dose (by 83%, p<0.001) after 6 months that were maintained over time, with 78% of patients able to stop oral corticosteroid therapy. Patients improved their Asthma Control Test (ACT) score (from 11.7±5.1 to 16.9±5.35, p<0.0001), Asthma Control Questionnaire (ACQ) score (from 2.88±1.26 to 1.77±1.32, p<0.0001) and Asthma Quality of Life Questionnaire score (+1.04, p<0.0001) at 6 months and this was maintained during follow-up. Only 35% and 43% of patients reached asthma control according to an ACT score ≥20 and ACQ score <1.5, respectively. We observed stable post-bronchodilation lung function over time and a significant reduction in sputum eosinophil count, with 85% of patients exhibiting sputum eosinophil counts <3% after 6 months (p<0.01) with no effect on exhaled nitric oxide fraction.

Conclusion

In our real-life study, we confirm the results published in randomised controlled trials showing a sharp reduction in exacerbations and oral corticosteroid therapy, an improvement in asthma control and quality of life, and a dramatic reduction in sputum eosinophil count.

Patients With Asthma Only Sensitized to Staphylococcus aureus Enterotoxins Have More Exacerbations, Airflow Limitation, and Higher Levels of Sputum IL-5 and IgE

BACKGROUND

Staphylococcus aureus enterotoxins (SE) may act as superantigens and induce an intense T-cell activation, causing local production of polyclonal IgE and resultant eosinophil activation.

OBJECTIVE

To assess whether asthma with sensitization to SE but not to common aeroallergens (AAs) displays different inflammatory characteristics.

METHODS

We conducted a prospective study on a series of 110 consecutive patients with asthma recruited from the University Asthma Clinic of Liège. We compared clinical, functional, and inflammatory characteristics of this general population of patients with asthma categorized into 4 groups according to sensitization to AAs and/or SE. We also compared sputum supernatant cytokines in patients sensitized to SE or not.

RESULTS

Patients with asthma sensitized only to AAs represented 30%, while 29% were sensitized to both AAs and SE. One-fifth of the population had no specific IgE. Sensitization to SE but not to AA (21%) was associated with later onset of disease, higher rate of exacerbations, nasal polyps, and more severe airway obstruction. As for airway type 2 biomarkers, patients presenting with specific IgE against SE displayed higher fractional exhaled nitric oxide, sputum IgE, and sputum IL-5 levels but not IL-4. We confirm that the presence of specific IgE against SE is associated with elevated serum IgE to levels well above those observed in patients sensitized only to AAs.

CONCLUSIONS

Our study suggests that asthma specialists should measure specific IgE against SE during the phenotyping process because it may allow the identification of a subgroup of patients with more asthma exacerbations, more nasal polyposis and chronic sinusitis, lower lung function, and more intense type 2 inflammation.

Ciliary dyskinesia in severe asthma is not affected by chronic mucus hypersecretion

Chronic mucus hypersecretion (CMH) is linked to increased asthma severity. Ciliary dyskinesia is present in severe asthma but CMH was not associated with a worse ciliary dysfunction, suggesting another mechanism to explain chronic cough and phlegm. https://bit.ly/3JNUgGr.

Sputum Type 2 Markers Could Predict Remission in Severe Asthma Treated With Anti-IL-5

BACKGROUND

Biotherapies targeting IL-5 allow a tangible improvement of asthma. However, all patients do not respond the same way to these treatments. Even if high blood eosinophil counts seem to be associated with a reduction in exacerbations with treatment targeting IL-5, we lack biomarkers for the prediction of remission after these very expensive treatments.

RESEARCH QUESTION

Are there biomarkers of remission after therapy targeting IL-5 in the sputum of patients with severe eosinophilic asthma?

STUDY DESIGN AND METHODS

This observational study included 52 patients with severe asthma initiated with anti-IL-5 therapy and recruited from the asthma clinic of the Centre Hospitalier Universitaire of Liege, Belgium. Remission was defined as patients who combined the following at 1 year after therapy: no chronic treatment with oral corticosteroids; no exacerbation; asthma control questionnaire score < 1.5, asthma control test score > 19, or both; FEV1 of ≥ 80% predicted, improvement of FEV1 of ≥ 10%, or both; and a blood eosinophil count < 300 cells/μL. Eosinophil peroxidase (EPX), IgE, IL-3, IL-4, IL-5, IL-13, IL-25, IL-33, granulocyte-macrophage colony-stimulating factor, thymic stromal lymphopoietin (TSLP), and eotaxin-1 levels were measured in the sputum of these patients before anti-IL-5 treatment.

RESULTS

Among the 52 patients, 11 were classified as being in remission. These patients were characterized by higher sputum eosinophil, macrophage, and lymphocyte counts, whereas the sputum neutrophil percentage was lower than in the nonremission group. In addition, the sputum eotaxin-1, TSLP, IL-5, EPX, and IgE protein levels were higher at baseline in the remission group compared with the nonremission group. Univariate regression analysis revealed that male vs female sex, sputum neutrophil percentage, eotaxin-1, IL-5, and EPX were potential predictors of remission.

INTERPRETATION

Sputum type 2 markers seemed to be potentially predictive of remission after anti-IL-5 therapy in a cohort of patients with severe eosinophilic asthma. These results need validation on a larger cohort.

Development and validation of a predictive model combining patient-reported outcome measures, spirometry and exhaled nitric oxide fraction for asthma diagnosis

Introduction

Although asthma is a common disease, its diagnosis remains a challenge in clinical practice with both over- and underdiagnosis. Here, we performed a prospective observational study investigating the value of symptom intensity scales alone or combined with spirometry and exhaled nitric oxide fraction (F _ENO) to aid in asthma diagnosis.

Methods

Over a 38-month period we recruited 303 untreated patients complaining of symptoms suggestive of asthma (wheezing, dyspnoea, cough, sputum production and chest tightness). The whole cohort was split into a training cohort (n=166) for patients recruited during odd months and a validation cohort (n=137) for patients recruited during even months. Asthma was diagnosed either by a positive reversibility test (≥12% and ≥200 mL in forced expiratory volume in 1 s (FEV₁)) and/or a positive bronchial challenge test (provocative concentration of methacholine causing a 20% fall in FEV₁ ≤8 mg·mL^-1). In order to assess the diagnostic performance of symptoms, spirometric indices and F _ENO, we performed receiver operating characteristic curve analysis and multivariable logistic regression to identify the independent factors associated with asthma in the training cohort. Then, the derived predictive models were applied to the validation cohort.

Results

63% of patients in the derivation cohort and 58% of patients in the validation cohort were diagnosed as being asthmatic. After logistic regression, wheezing was the only symptom to be significantly associated with asthma. Similarly, FEV₁ (% pred), FEV₁/forced vital capacity (%) and F _ENO were significantly associated with asthma. A predictive model combining these four parameters yielded an area under the curve of 0.76 (95% CI 0.66-0.84) in the training cohort and 0.73 (95% CI 0.65-0.82) when applied to the validation cohort.

Conclusion

Combining a wheezing intensity scale with spirometry and F _ENO may help in improving asthma diagnosis accuracy in clinical practice.

Predictors of change in asthma-related quality of life: a longitudinal real-life study in adult asthmatics

PURPOSE

Asthma negatively impacts health-related quality of life (HRQL). The objective is to investigate the longitudinal relationship between HRQL in asthma and disease control, demographic and clinical objective parameters in an adult population in real-life settings.

METHODS

We conducted a longitudinal study on adult asthmatics recruited from Liege University Hospital Asthma Clinic (Belgium) between 2011 and 2019. We selected those who had two visits and completed two patient-reported outcome measures (PROMs), the asthma control test (ACT) and the mini asthma quality of life questionnaire (AQLQ) (n = 290). AQLQ was the dependent variable. Demographic, functional and inflammatory characteristics, asthma control, and exacerbations were the independent variables. We applied generalized linear mixed models to identify the factors associated with change in AQLQ and its dimensions.

RESULTS

Median (IQR) time interval between the two visits was 7 (5-19) months. Overall, median (IQR) global AQLQ increased from 4.1 (3-5.1) to 4.6 (3.4-5.9) (p < 0.0001). All AQLQ dimensions significantly improved, apart the environmental one. AQLQ improved in patients who had both step-up and step-down pharmacological treatment as well as in patients reporting no change between the two visits. The fitted models indicated that change in ACT was the main predictor of change in AQLQ (p < 0.0001). A rise in 3 units in ACT predicted an improvement of 0.5 AQLQ (AUC-ROC = 0.85; p < 0.0001). Change in BMI inversely impacted global AQLQ (p < 0.01) and its activity dimension (p < 0.0001).

CONCLUSION

Asthma control and BMI are key predictors of asthma quality of life acting in an opposite direction. AQLQ may improve without step-up in the pharmacological treatment.

Revisiting differences between atopic and non-atopic asthmatics: When age is shaping airway inflammatory profile

Background

Atopic asthma is one of the most common asthma phenotypes and is generally opposed to the non-atopic counterpart. There have been very few large-scale studies comparing atopic and non-atopic asthmatics in terms of systemic and airway inflammation across the age spectrum.

Methods

Here, we have undertaken a retrospective study investigating 1626 patients (924 atopic and 702 non-atopic asthmatics) recruited from our university asthma clinic who underwent extensive clinical investigations including induced sputum. Atopy was defined by any positive specific IgE to common aeroallergens (>0,35 kU/L). We performed direct comparisons between the groups and sought to appreciate the influence of age on the airway and systemic inflammatory components. The study was approved by the ethics committee of the University Hospital of Liege (Ref. 2016/276). Informed consents were obtained from healthy subjects.

Results

Atopic asthmatics were younger (P < .001), had a higher male/female ratio (P < .001), an earlier disease onset (P < .001) and a greater proportion of treated rhinitis (P < .001) while non-atopic asthmatics had greater smoke exposure (P < .001), lower FEV₁/FVC ratio (P = .01) and diffusing capacity (P < .001). There was no difference between the 2 groups regarding FEV₁ (% predicted), asthma control, asthma quality of life and exacerbations in the previous 12 months. Regarding inflammation, atopic patients had higher FeNO levels (median = 28 ppb, P < .001), were more eosinophilic both in blood (median = 2.8%, P < .001) and in sputum (median = 2.2%, P < .001) while non-atopic patients displayed greater blood (median = 57%, P = .01) and sputum (median = 58.8%, P = .01) neutrophilic inflammation. However, stratifying patients by age showed that non-atopic asthmatics above 50 years old became equally eosinophilic in the sputum (P = .07), but not in the blood, as compared to atopic patients. Likewise, FeNO rose in non-atopic patients after 50 years old but remained, however, lower than in atopic patients.

Conclusions

We conclude that, while sharing many features, atopic group still differentiates from non-atopic asthmatics by demographics, functional and inflammatory profiles. When atopic asthmatics showed a constant eosinophilic pattern across the age spectrum, non-atopic asthmatics were found to be neutrophilic before the age of 50 but eosinophilic above 50 years old.

[Asthma in clinical practice: from inflammatory phenotypes to personalized treatment]

Asthma is a chronic inflammatory disease of the airways. Classification of asthma in different phenotypes has therapeutic implications and may lead to personalized medicine. Induced sputum is the gold standard for asthma phenotyping but is complex, time-consuming and not widely available. The combination of different biomarkers such as exhaled nitric oxide, blood eosinophils and total serum IgE levels allows the prediction of inflammatory phenotype in 58% of asthmatic patients when sputum is not available. We recently demonstrated the interest of measuring volatile organic compounds in exhaled breath to phenotype asthma. These compounds could play an important role in the future to predict the response to expensive biologicals available in severe asthma to reduce exacerbations and the use of systemic corticosteroids.

Predictors of asthma-related quality of life in a large cohort of asthmatics: A cross-sectional study in a secondary care center

Background

In recent decades, asthma-related quality of life questionnaires have joined objective clinical indicators as important outcome measures. In this study, we sought to investigate the predictors of asthma-related quality of life in a large cohort of patients recruited from a secondary care center.

Methods

We conducted a cross-sectional study on asthmatics (N = 1301) recruited from the Liège University Hospital asthma clinic (Belgium). After performing a descriptive analysis highlighting the distribution of scores from the Mini Asthma Quality of Life Questionnaire (Mini AQLQ) and its four dimensions (symptoms, activity limitation, emotional function, and environmental stimuli), we did multiple regression analysis to identify the independent predictors of AQLQ.

Results

Multiple regression beta analysis showed that AQLQ and its four dimensions were primarily associated with asthma control (p < 0.0001 in all instances). Female gender was associated with a lower score for the AQLQ's activity and environmental dimensions (p < 0.05 for both), while current smokers had a higher score on the AQLQ's environmental dimension (p < 0.0001). The burden of asthma treatment was associated with a lower score for the AQLQ's emotional (p < 0.05) and environmental (p < 0.05) dimensions. BMI was associated with a lower score in the AQLQ's activity dimension (p < 0.0001), while the opposite was true for the FeNO test (p < 0.0001). Sputum neutrophils were inversely related to the score for the AQLQ's symptom dimension (p < 0.05), whereas post-bronchodilator FEV₁ showed a positive relationship for that same dimension (p < 0.05).

Conclusion

Asthma control is the main predictor of AQLQ score and impacts all its dimensions, but demographic, functional, and airway inflammatory parameters may also influence some dimensions of the AQLQ.

Breathomics to diagnose systemic sclerosis using thermal desorption and comprehensive two-dimensional gas chromatography high-resolution time-of-flight mass spectrometry

Systemic sclerosis is a rare autoimmune disease associated with rapidly evolving interstitial lung disease, responsible for the disease severity and mortality. Specific biomarkers enabling the early diagnosis and prognosis associated with the disease progression are highly needed. Volatile organic compounds in exhaled breath are widely available and non-invasive and have the potential to reflect metabolic processes occurring within the body. Comprehensive two-dimensional gas chromatography coupled to high-resolution mass spectrometry was used to investigate the potential of exhaled breath to diagnose systemic sclerosis. The exhaled breath of 32 patients and 30 healthy subjects was analyzed. The high resolving power of this approach enabled the detection of 356 compounds in the breath of systemic sclerosis patients, which was characterized by an increase of mainly terpenoids and hydrocarbons. In addition, the use of 4 complementary statistical approaches (two-tailed equal variance t-test, fold change, partial least squares discriminant analysis, and random forest) resulted in the identification of 16 compounds that can be used to discriminate systemic sclerosis patients from healthy subjects. Receiver operating curves were generated that provided an accuracy of 90%, a sensitivity of 92%, and a specificity of 89%. The chemical identification of eight compounds predictive of systemic sclerosis was validated using commercially available standards. The analytical variations together with the volatile composition of room air were carefully monitored during the timeframe of the study to ensure the robustness of the technique. This study represents the first reported evaluation of exhaled breath analysis for systemic sclerosis diagnosis and provides surrogate markers for such disease.

Chronic infection with Chlamydia pneumoniae in asthma: a type-2 low infection related phenotype

Background

Chlamydia pneumoniae and Mycoplasma pneumoniae have been implicated in the pathogenesis of asthma and are responsible for chronic inflammation when host immune system fails to eradicate the bacteria.

Method

We performed a prospective study on 410 patients who underwent a visit at the asthma clinic of CHU of Liege between June 2016 and June 2018 with serology testing for C. pneumoniae and M. pneumoniae.

Results

65% of our asthmatic population had serum IgA and/or IgG towards C. pneumoniae, while only 12.6% had IgM and/or IgG against M. pneumoniae. Compared to seronegative asthmatics, asthmatics with IgA+ and IgG+ against C. pneumoniae were more often male and older with a higher proportion of patients with smoking history. They received higher doses of inhaled corticosteroids (ICS) and displayed lower FEV₁/FVC ratio, higher RV/TLC ratio and lower conductance. They had higher levels of fibrinogen, though in the normal range and had lower sputum eosinophil counts. Patients with IgA− and IgG+ against C. pneumoniae were older and had higher blood monocyte counts and alpha-1-antitrypsin levels as compared to seronegative patients. Patients with IgM and/or IgG towards M. pneumoniae were more often males than seronegative asthmatics. In a subpopulation of 14 neutrophilic asthmatics with Chlamydia pneumoniae IgA + /IgG + treated with macrolides, we found a significant decrease in blood neutrophils and normalization of sputum neutrophil count but no effect on asthma quality of life and exacerbations.

Conclusion

Positive Chlamydia serologic test is more common than positive Mycoplasma serology. Asthmatics with IgA and IgG against C. pneumoniae have more severe disease with increased airway obstruction, higher doses of ICS, more signs of air trapping and less type-2 inflammation.

Asthma in elderly is characterized by increased sputum neutrophils, lower airway caliber variability and air trapping

BACKGROUND

Elderly asthmatics represent an important group that is often excluded from clinical studies. In this study we wanted to present characteristics of asthmatics older than 70 years old as compared to younger patients.

METHODS

We conducted a retrospective analysis on a series of 758 asthmatics subdivided in three groups: lower than 40, between 40 and 70 and older than 70. All the patients who had a successful sputum induction were included in the study.

RESULTS

Older patients had a higher Body Mass Index, had less active smokers and were more often treated with Long Acting anti-Muscarinic Agents. We found a significant increase in sputum neutrophil counts with ageing. There was no significant difference in blood inflammatory cell counts whatever the age group. Forced expiratory volume in one second (FEV₁) and FEV₁/FVC values were significantly lower in elderly who had lower bronchial hyperresponsiveness and signs of air trapping. We found a lower occurrence of the allergic component in advanced ages. Asthmatics older than 70 years old had later onset of the disease and a significant longer disease duration.

CONCLUSION

Our study highlights that asthmatics older than 70 years old have higher bronchial neutrophilic inflammation, a poorer lung function, signs of air trapping and lower airway variability. The role of immunosenescence inducing chronic low-grade inflammation in this asthma subtype remains to be elucidated.

Asthmatics with concordant eosinophilic disease classified according to their serum IgE status

BACKGROUND

Eosinophilic inflammation has long been associated with asthma. Looking at systemic and airway eosinophilia, we have recently identified a group of patients exhibiting diffuse eosinophilic inflammation. Among the mechanisms governing eosinophilic inflammation, IgE-mediated mast cell activation is a key event leading to eosinophilia in atopic asthmatics.

METHODS

We conducted a retrospective study on our asthma clinic database containing more than 1500 patients and identified 205 asthmatics with successful sputum induction and concordant eosinophilic phenotype. This phenotype was defined as a sputum eosinophil count≥3% and a blood eosinophils concentration≥400cells/mm³. IgE-high atopic phenotype was characterized by the presence of at least one positive specific IgE (>0.35kU/L) to common aeroallergens and a raised total serum IgE (≥113kU/L).

RESULTS

The largest group of asthmatics displaying concordant eosinophilic phenotype had a raised total serum IgE and atopy (45%). IgE-low non-atopic concordant eosinophilic asthma was a predominantly late onset disease, exhibited a more intense airway eosinophilic inflammation (P<0.05), required more often maintenance treatment with oral corticosteroids (P<0.05) but, surprisingly, had a reduced level of bronchial hyperresponsiveness to methacholine (P<0.05) despite similar baseline airway calibre impairment.

CONCLUSION

The more severe airway eosinophilic inflammation in IgE-low non-atopic asthmatics despite similar treatment with ICS and a higher burden of OCS points to a certain corticosteroid resistance in this asthma phenotype.

Clinical and biological factors associated with irreversible airway obstruction in adult asthma

BACKGROUND AND OBJECTIVE

Airway remodeling, as many other factors, may lead to lung function decline and irreversible airflow obstruction (IRAO) in asthma. This study was undertaken in order to highlight predictors of incomplete reversibility of airflow obstruction in adult asthmatics to identify patients with poorer prognosis and improve their care, and decrease morbidity.

METHODS

A retrospective study was conducted in 973 asthmatics recruited from the University Asthma Clinic of Liege. Patients with IRAO (post-BD FEV₁/FVC<0.7 & FEV₁<80% predicted) were compared to patients with reversible airway obstruction (RAO) (post-BD FEV₁/FVC≥0.7 & FEV₁≥80% predicted). TGF-β was measured in sputum supernatant of 85 patients.

RESULTS

Seventeen percent of asthmatics presented with IRAO. These patients were significantly older, more smokers, with a lower proportion of female, a longer disease duration, were more poorly controlled with a lower quality of life. This sub-population of asthmatics also showed more often elevated blood and sputum eosinophils and neutrophils, and higher exacerbation and hospitalisation rates in the previous year. The multivariable analysis revealed male gender, longer disease duration, cigarette smoking, ACQ score, sputum eosinophils and neutrophils, ICS dose and OCS maintenance, BMI, and asthma onset as variables independently linked to IRAO. Total TGF-β levels appeared higher in patients with IRAO (n = 38) compared to patients with RAO (n = 47).

CONCLUSION

These data show that risk factors for IRAO are male gender, smoking, a longer disease duration, uncontrolled asthma, eosinophilic or neutrophilic airway inflammation, lower BMI, and later asthma onset. Moreover, TGF-β levels are higher in IRAO.

Comprehensive Cluster Analysis for COPD Including Systemic and Airway Inflammatory Markers

Chronic obstructive pulmonary disease (COPD) is a complex, multidimensional and heterogeneous disease. The main purpose of the present study was to identify clinical phenotypes through cluster analysis in adults suffering from COPD. A retrospective study was conducted on 178 COPD patients in stable state recruited from ambulatory care at University hospital of Liege. All patients were above 40 years, had a smoking history of more than 20 pack years, post bronchodilator FEV1/FVC <70% and denied any history of asthma before 40 years. In this study, the patients were described by a total of 84 mixed sets of variables with some missing values. Hierarchical clustering on principal components (HCPC) was applied on multiple imputation. In the final step, patients were classified into homogeneous distinct groups by consensus clustering. Three different clusters, which shared similar smoking history were found. Cluster 1 included men with moderate airway obstruction (n = 67) while cluster 2 comprised men who were exacerbation-prone, with severe airflow limitation and intense granulocytic airway and neutrophilic systemic inflammation (n = 56). Cluster 3 essentially included women with moderate airway obstruction (n = 55). All clusters had a low rate of bacterial colonization (5%), a low median FeNO value (<20 ppb) and a very low sensitization rate toward common aeroallergens (0-5%). CAT score did not differ between clusters. Including markers of systemic airway inflammation and atopy and applying a comprehensive cluster analysis we provide here evidence for 3 clusters markedly shaped by sex, airway obstruction and neutrophilic inflammation but not by symptoms and T2 biomarkers.

[Yoga to improve asthma control in severe asthmatics treated with biologics]

We conducted a prospective observational study to evaluate the efficacy of yoga in poorly controlled severe asthmatic patients treated with maximal inhaled therapy and biologics. The objective of yoga was to improve breathing consciousness, exercising controlled ventilation with and without retention, abdominal breathing observation, improvement of inspiratory and expiratory muscles, opening of the chest, diaphragm exercises and relaxation. We measured exhaled nitric oxide, forced expiratory volume in one second, forced vital capacity, asthma control and quality of life questionnaires, anxiety and depression questionnaires before and after the tenth yoga course (performed twice a week). Half of the patients who were invited to participate to the study declined due to organization problems. Two patients were excluded due to bronchitis and arthralgia respectively. The analysis of the data from 12 participants revealed significant improvement in asthma control and asthma quality of life questionnaires and a reduction of anxiety.The regular practice of yoga in severe asthmatics insufficiently controlled despite maximal inhaled treatment and biotherapy seems to be an interesting complementary option to improve asthma control. Our results must be confirmed in larger randomized controlled trials.

Are type-2 biomarkers of any help in asthma diagnosis?

T2 biomarkers lack the accuracy to make an asthma diagnosis in patients with suggestive symptoms https://bit.ly/3hYnnHu.

[Asthma : the contribution of biotherapies]

Asthma is a chronic heterogeneous airway disease. There are different asthma inflammatory phenotypes with various responses to treatment and different disease severities. When asthma requires chronic systemic corticosteroids or hospitalizations despite maximal inhaled therapies in asthmatic patients in whom comorbidities have been managed and who are considered as compliant, the pulmonologist may propose biological treatment to reduce exacerbations and the dose of systemic corticosteroids. During the last ten years, the number of biologics for the management of type-2 severe asthma has increased. Anti-IgE monoclonal antibodies (omalizumab) are available for more than ten years and recommended in severe allergic asthma. New biologics are now available to block IL-5 (mepolizumab, reslizumab) or its receptor (benralizumab). These treatments allow a reduction of exacerbations and of the dose of systemic corticosteroids, an improvement in asthma control, in asthma quality of life and for some of them, an increase in lung function. New biologics will soon be available in Belgium for the management of severe asthma. In addition to the improvement of asthma control in severe asthma, biological treatments have improved the understanding of the mechanisms leading to severe asthma.

Predictors of a good response to inhaled corticosteroids in obesity-associated asthma

INTRODUCTION

Asthma in obese subjects is poorly understood. According to GINA guidelines, pulmonologists increase ICS in case of poor asthma control but lung volume restriction may also worsen respiratory symptoms in obese asthmatics leading to overtreatment in this subpopulation.

METHODS

We conducted a retrospective study on 1217 asthmatics recruited from University Hospital of Liege. 92 patients with a BMI ≥30 came at least two times at the asthma clinic (mean interval: 335 days). In this obese population, we identified predictors of good (decrease in ACQ ≥0.5) versus poor response (rise in ACQ ≥0.5) to ICS step-up therapy.

RESULTS

Obese asthmatics had a poorer asthma control and quality of life as compared to non-obese and exhibited reduced FVC, higher levels of blood leucocytes and markers of systemic inflammation. The proportion of asthma inflammatory phenotypes was similar to that observed in a general population of asthmatics. Among uncontrolled obese asthmatics receiving ICS step-up therapy, 53% improved their asthma control while 31% had a worsening of their asthma. Uncontrolled obese asthmatics showing a good response to increase in ICS had higher ACQ, lower CRP levels, higher sputum eosinophil counts and higher FeNO levels at visit 1. Uncontrolled obese asthmatics that worsened after increasing the dose of ICS had lower FVC, lower sputum eosinophil counts and higher sputum neutrophil counts.

CONCLUSION

We observed poorer asthma control in obese asthmatics despite similar bronchial inflammation. Managing obese asthmatics according to ACQ alone seems to underestimate asthma control and the contribution of restriction to dyspnea. Increasing the dose of ICS in the absence of sputum eosinophilic inflammation or in the presence of restriction or bronchial neutrophilia led to poorer asthma control. In those patients, management of obesity should be the first choice.

Assessment of diagnostic accuracy of lung function indices and FeNO for a positive methacholine challenge

Demonstration of bronchial hyperresponsiveness is a key feature in asthma diagnosis. Methacholine challenge has proved to be a highly sensitive test to diagnose asthma in patients with chronic respiratory symptoms and preserved baseline lung function (FEV1 > 70% pred.) but is time consuming and may sometimes reveal unpleasant to the patient. We conducted a retrospective study on 270 patients recruited from the University Asthma Clinic of Liege. We have compared the values of several lung function indices and fractional exhaled nitric oxide (FeNO) in predicting a provocative methacholine concentration ≤16 mg/ml on a discovery cohort of 129 patients (57 already on ICS) and on a validation cohort of 141 patients (66 already on ICS). In the discovery study (n = 129), 85 patients (66%) had a positive methacholine challenge with PC20M ≤ 16 mg/ml. Those patients had lower baseline % predicted FEV1 (92% vs. 100%; p < 0.01), lower FEV1/FVC ratio (79% vs. 82%; p < 0.05), higher RV/TLC ratio (114% vs. 100%; p < 0,0001), lower SGaw (specific conductance) (0.76 vs. 0.95; p < 0,001) and higher FeNO (29 ppb vs. 19 ppb; p < 0,01). When performing ROC curve the RV/TLC ratio provided the greatest AUC (0.74, p < 0.001), sGAW had intermediate AUC of 0.69 (p < 0.001) while FeNO, FEV1 and FEV1/FVC ratio were modestly predictive (AUC of 0.65 (p < 0.05), 0,67 (p < 0.001) and 0,63 (p < 0.001). These results were confirmed in the validation study (n = 141). Based on a logistic regression analysis, significant variables associated with positive methacholine challenge were FeNO and RV/TLC (% Pred). A combined application of FeNO and RV/TLC (% Pred) for predicting the PC20M had a specificity of 85%, a sensitivity of 59% and an AUC of 0.79. In the validation study, three variables (RV/TLC, FeNO and FEV1) were independently associated with positive methacholine challenge and the combination of these three variables yielded a specificity of 77%, a sensitivity of 39% and an AUC of 0.77. The RV/TLC ratio combined to FeNO may be of interest to predict significant methacholine bronchial hyperresponsiveness.

Real-word experience with mepolizumab: Does it deliver what it has promised?

BACKGROUND

Randomized control trials performed in selected populations of severe eosinophilic asthmatics have shown that mepolizumab, an anti-IL5 therapy, was able to reduce exacerbations and OCS maintenance dose and in some studies, to improve asthma control and lung function.

OBJECTIVE

The aim of this study was to confirm the results of the RCTs in real-life in a population of 116 severe eosinophilic asthmatics treated with mepolizumab and who were followed up at the asthma clinic every month for at least 18 months. Severe asthmatics underwent FENO, lung function, asthma control and quality of life questionnaires, sputum induction and gave a blood sample at baseline, after 6 months and then every year.

RESULTS

We found a significant reduction in exacerbations by 85% after 6 months (P < .0001), which was maintained over time. We also found a significant and maintained reduction by 50% in the dose of oral corticosteroids (P < .001). Patients improved their ACT (+5.31pts, p<0.0001) ACQ (-1.13pts, P < .0001) and their AQLQ score (+1.24, P < .0001) at 6 months and this was maintained during follow-up. Only 37% reached asthma control (ACQ <1.5, ACT> 20). We observed a progressive increase in post-BD FEV1 that reached significance after 18 months (190ml or 11%, P < .01). Patients improving their FEV1had higher baseline sputum eosinophils than those not improving airway caliber. We found a significant reduction in sputum eosinophil counts by 60% after 6 months (P < .01) and a maintained reduction in blood eosinophil counts by 98% (P < .0001).

CONCLUSION

In our real-life study, we confirm the results published in the RCTs showing a sharp reduction in exacerbation and oral corticosteroids dose and an improvement in asthma control and quality of life.

CLINICAL RELEVANCE

Mepolizumab is efficient in severe eosinophilic asthma in real life.

Effectiveness of omalizumab on patient reported outcomes, lung function, and inflammatory markers in severe allergic asthma

BACKGROUND

Omalizumab arose as a therapeutic option in patients suffering from moderate to severe refractory allergic asthma. It acts as a humanized monoclonal antibody neutralizing circulating IgE antibodies. Randomized clinical trials and real life clinical studies have already confirmed benefits, cost-effectiveness and applicability of the medication.

METHOD

Our study retrospectively reports on the clinical outcomes and airway inflammation in 157 severe allergic asthmatics who were initiated with omalizumab between 2007 and 2019.

RESULTS

After 4 months of therapy, 76% of the patients were judged to have benefited from omalizumab and were admitted to prolonged treatment. During follow-up, we observed an improvement in asthma control, quality of life and spirometric performance. There was also a sustained reduction in exacerbation rate over the years. As for T2 biomarkers, FeNO significantly decreased and, in a subgroup of patients who had repeated sputum inductions, there was also significant reduction in sputum eosinophils but no change in blood eosinophil count. Lastly, we found a correlation between high FeNO levels at baseline and reduction in ACQ scores at 1 year.

CONCLUSION

We conclude that omalizumab shows effectiveness in severe allergic asthma in a real life setting, by reducing exacerbation rate, improving patient perspective outcomes and airway calibre, together with reducing type-2 airway inflammation.

Exhaled Volatile Organic Compounds Are Able to Discriminate between Neutrophilic and Eosinophilic Asthma

Rationale: Analysis of exhaled breath for asthma phenotyping using endogenously generated volatile organic compounds (VOCs) offers the possibility of noninvasive diagnosis and therapeutic monitoring. Induced sputum is indeed not widely available and markers of neutrophilic asthma are still lacking.Objectives: To determine whether analysis of exhaled breath using endogenously generated VOCs can be a surrogate marker for recognition of sputum inflammatory phenotypes.Methods: We conducted a prospective study on 521 patients with asthma recruited from the University Asthma Clinic of Liege. Patients underwent VOC measurement, fraction of exhaled nitric oxide (Fe_NO) spirometry, sputum induction, and gave a blood sample. Subjects with asthma were classified in three inflammatory phenotypes according to their sputum granulocytic cell count.Measurements and Main Results: In the discovery study, seven potential biomarkers were highlighted by gas chromatography-mass spectrometry in a training cohort of 276 patients with asthma. In the replication study (n = 245), we confirmed four VOCs of interest to discriminate among asthma inflammatory phenotypes using comprehensive two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Hexane and 2-hexanone were identified as compounds with the highest classification performance in eosinophilic asthma with accuracy comparable to that of blood eosinophils and Fe_NO. Moreover, the combination of Fe_NO, blood eosinophils, and VOCs gave a very good prediction of eosinophilic asthma (area under the receiver operating characteristic curve, 0.9). For neutrophilic asthma, the combination of nonanal, 1-propanol, and hexane had a classification performance similar to Fe_NO or blood eosinophils in eosinophilic asthma. Those compounds were found in higher levels in neutrophilic asthma.Conclusions: Our study is the first attempt to characterize VOCs according to sputum granulocytic profile in a large population of patients with asthma and provide surrogate markers for neutrophilic asthma.

Bronchodilation Test with Inhaled Salbutamol Versus Bronchial Methacholine Challenge to Make an Asthma Diagnosis: Do They Provide the Same Information?

BACKGROUND

Methacholine bronchial challenge and bronchodilation to salbutamol are key tests in clinical practice to make asthma diagnosis.

OBJECTIVE

To assess the concordance between the 2 tests and to see whether they actually identify the same population of asthmatics.

METHOD

We conducted a retrospective study using our asthma clinic database to see how methacholine bronchial challenge compared to bronchodilation to salbutamol in untreated patients with recurrent or chronic symptoms suspicious of asthma. We identified 194 untreated patients with baseline forced expiratory volume in 1 second (FEV₁) ≥70% predicted who had both a bronchodilation test with salbutamol and a methacholine bronchial challenge 7 to 14 days apart. A positive bronchial challenge was a provocative concentration of methacholine causing a 20% fall in FEV₁ ≤16 mg/mL, whereas a positive bronchodilation test was a reversibility to 400 μg inhaled salbutamol ≥12% from baseline and 200 mL.

RESULTS

Overall, asthma diagnosis was confirmed in 91% of cases leaving 9% of subjects with double negative tests. Isolated positive methacholine challenge was found in 71% of subjects, double positive tests in 17%, whereas isolated significant bronchodilation to salbutamol was rare (3%). There was no correlation between provocative concentration of methacholine causing a fall in FEV₁ of 20% (PC20M) and the magnitude of salbutamol reversibility (P = .10). Baseline FEV₁/forced vital capacity ratio inversely correlated with reversibility to salbutamol (P < .001) but not with PC20M (P = .1). No difference was found between the groups regarding demographic and immunoinflammatory features, including the proportion of eosinophilic asthma.

CONCLUSION

We conclude that methacholine challenge outperforms reversibility to salbutamol to diagnose asthma without selecting patients with distinct inflammatory profile. Baseline airway obstruction predicts magnitude of reversibility but not hyperresponsiveness.