Type 2 biomarker expression (FeNO and blood eosinophils) is higher in severe adult-onset than in severe early-onset asthma

Relationship between fraction of exhaled nitric oxide and peripheral eosinophilia in asthma

BACKGROUND

Achieving disease control is the goal of asthma management. Serum or sputum eosinophil counts have been known traditional means of assessing eosinophilic airway inflammation in asthma, which is vital in predicting response to corticosteroid therapy which ultimately promotes control of the disease. Evidence suggests that fraction of exhaled nitric oxide (FeNO) may be a more useful non-invasive surrogate biomarker for the assessment of eosinophilic airway inflammation and could help with the timely adjustment of inhaled corticosteroid therapy in the uncontrolled asthma patient. The relationship between FeNO and other markers of airway inflammation has been variable in literature, with limited data in sub-Saharan Africa where FeNO testing is very sparse. We sought to define the relationship between FeNO levels, serum eosinophil counts, spirometry measures and symptom control among asthma patients.

MATERIALS AND METHODS

The study was conducted at the Asthma Clinic of a large tertiary hospital. This study included 82 patients with physician-diagnosed asthma being regularly managed at the clinic. All participants were taken through the asthma control test (ACT), had FeNO and spirometry measurements taken according to the American Thoracic Society (ATS) guidelines. Blood samples were obtained from all participants for serum eosinophil counts. Correlation coefficient was used to ascertain the relationship between FeNO levels and serum eosinophil counts, ACT scores, and spirometry measurements. Logistic regression was used to examine the association between high FeNO and abnormal FEV1 percentage predicted (<80%) with adjustments for age, sex, and BMI.

RESULTS

A total of 82 patients with asthma were included in the study, with higher prevalence of females (72%). Majority (40.2%) of the patients were found in the 60 and above age category. The median FeNO level and ACT score was 42.00 (26.00-52.50) parts per billion (ppb) and 20.0 (18-23) respectively. The median serum eosinophil counts was 0.25(0.90-0.38) × 109/L. The median FeNO levels were significantly higher in patients with partly and very poorly controlled asthma than in the well-controlled group (p < 0.001). A total of 47(57%) of the patients were classified as having well controlled asthma and 35 (42%) uncontrolled. FeNO correlated with serum eosinophil counts (r = 0.450, p < 0.001), ACT (r = -0.648, p < 0.001), and FEV1 percentage predicted (r = -0.353, p = 0.001). High FeNO (>50 ppb) was associated with an over fivefold increased risk of having an abnormal FEV1 percentage predicted.

CONCLUSION

FeNO levels significantly correlated with the ACT scores, serum eosinophil counts and FEV1% predicted among the asthma patients who were on inhaled corticosteroid therapy. High FeNO was significantly associated with abnormal FEV1 percentage predicted. We suggest that the point of care assessment of FeNO is a reliable marker of eosinophilic inflammation in our cohort of patients and together with 'ACT scores' in our asthma clinics could increase asthma control rates.

Remission in asthma

PURPOSE OF REVIEW

To review the current concepts of remission in asthma.

RECENT FINDINGS

Until 2023, asthma guidelines have been promoting the concept of disease control, recommending the step-wise addition of drugs until the best possible disease control is achieved. With the advent of highly effective, anti-inflammatory disease-modifying antiasthmatic drugs (DMAADs), treatment goals of asthma have changed. Several national guidelines have now announced remission as a general treatment goal in asthma. Currently, all guidelines agree that asthma remission is defined by the presence of at least three characteristics over a period of at least one 1 year: absence of exacerbations, no systemic corticosteroid use for the treatment of asthma and minimal asthma-related symptoms. In the future, a generally accepted, evidence-based and easy-to-use definition of remission will be needed for daily clinical practice. It is clear, however, that precise phenotyping (including measurement of biomarkers) is an essential prerequisite to achieve clinical remission in each individual patient.

SUMMARY

Remission has been included as the treatment goal in asthma in several national guidelines, reflecting the paradigm shift in asthma, from short-term symptom control to long-term symptom prevention. An international consensus on the criteria for asthma remission is expected in the near future.

[Update on asthma 2024 - what the ENT specialist needs to know]

The lifetime prevalence of 8.6% of asthma in Germany reflects the high medical and socioeconomic impact of the disease. Asthma treatment goals have changed during the last decades: from symptom control to symptom prevention, with highly effective, disease-modifying anti-asthmatic drugs (DMAADs) aiming at asthma remission. In order to achieve this goal, phenotyping of patients (including an evaluation of allergies and type 2 biomarkers) is crucial for personalized treatment. The identification and effective treatment of concomitant diseases, such as allergic rhinitis or chronic rhinosinusitis with nasal polyps (CRSwNP), plays a major role for successful treatment. This underlines the importance of interdisciplinary collaboration of otolaryngologists and respiratory physicians in the management of patients with asthma. This CME article informs the reader about current guidelines on the diagnosis and treatment of asthma, focusing on clinically relevant recommendations for ENT physicians.

Atopic dermatitis: Correlation of distinct risk factors with age of onset in adulthood compared to childhood

BACKGROUND

Atopic dermatitis (AD) has long been regarded as a primarily pediatric disease. However, there is growing evidence for a high rate of adult-onset AD. We aimed to characterize factors associated with adult-onset versus childhood-onset AD and controls.

METHODS

We analyzed cross-sectional data of the CK-CARE-ProRaD cohorts Bonn, Augsburg, Davos, Zürich of 736 adult patients stratified by age of AD onset (childhood-onset <18 years: 76.4% (subsets: 0 to 2; ≥2 to 6; ≥7 to 11; ≥12 to 18); adult-onset ≥18 years: 23.6% (subsets: ≥18 to 40; ≥41 to 60; ≥61) and 167 controls (91 atopic, 76 non-atopic)).

RESULTS

We identified active smoking to be associated with adult-onset AD versus controls (adjusted Odds Ratio (aOR) = 5.54 [95% Confidence Interval: 1.06-29.01] vs. controlsnon-atopic , aOR = 4.03 [1.20-13.45] vs. controlsatopic ). Conjunctivitis showed a negative association versus controlsatopic (aOR = 0.36 [0.14-0.91]). Food allergy (aOR = 2.93 [1.44-5.96]), maternal food allergy (aOR = 9.43 [1.10-80.95]), palmar hyperlinearity (aOR = 2.11 [1.05-4.25]), and academic background (aOR = 2.14 [1.00-4.54]) increased the odds of childhood-onset AD versus controlsatopic . Shared AD-associated factors were maternal AD (4-34x), increased IgE (2-20x), atopic stigmata (2-3x) with varying effect sizes depending on AD onset and control group. Patients with adult-compared to childhood-onset had doubled odds of allergic rhinitis (aOR = 2.15 [1.12-4.13]), but reduced odds to feature multiple (3-4) atopic comorbidities (aOR = 0.34 [0.14-0.84]). Adult-onset AD, particularly onset ≥61 years, grouped mainly in clusters with low contributions of personal and familial atopy and high frequencies of physical inactivity, childhood-onset AD, particularly infant-onset, mainly in "high-atopic"-clusters.

CONCLUSIONS

The identified associated factors suggest partly varying endo- and exogeneous mechanisms underlying adult-onset versus childhood-onset AD. Our findings might contribute to better assessment of the individual risk to develop AD throughout life and encourage prevention by non-smoking and physical activity as modifiable lifestyle factors.

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

Validation of a Pathological Score for the Assessment of Bronchial Biopsies in Severe Uncontrolled Asthma: Beyond Blood Eosinophils

BACKGROUND

Blood eosinophil count (BEC) is currently used as a surrogate marker of T2 inflammation in severe asthma but its relationship with tissue T2-related changes is elusive. Bronchial biopsy could add reliable information but lacks standardization.

OBJECTIVES

To validate a systematic assessment of the bronchial biopsy for the evaluation of severe uncontrolled asthma (SUA) by standardizing a pathological score.

METHODS

A systematic assessment of submucosal inflammation, tissue eosinophilic count/field (TEC), goblet cells hyperplasia, epithelial changes, basement membrane thickening, prominent airway smooth muscle and submucosal mucous glands was initially agreed and validated in representative bronchial biopsies of 12 patients with SUA by 8 independent pathologists. In a second phase, 62 patients with SUA who were divided according to BEC≥300cells/mm³ or less underwent bronchoscopy with bronchial biopsies and the correlations between the pathological findings and the clinical characteristics were investigated.

RESULTS

The score yielded good agreement among pathologists regarding submucosal eosinophilia, TEC, goblet cells hyperplasia and mucosal glands (ICC=0.85, 0.81, 0.85 and 0.87 respectively). There was a statistically significant correlation between BEC and TEC (r=0.393, p=0.005) that disappeared after correction by oral corticosteroids (OCS) use (r=0.170, p=0.307). However, there was statistically significant correlation between FeNO and TEC (r=0.481, p=0.006) that was maintained after correction to OCS use (r=0.419, p=0.021). 82.4% of low-BEC had submucosal eosinophilia, 50% of them moderate to severe.

CONCLUSION

A standardized assessment of endobronchial biopsy is feasible and could be useful for a better phenotyping of SUA especially in those receiving OCS.

Biomarkers of asthma relapse and lung function decline in adults with spontaneous asthma remission: A population-based cohort study

BACKGROUND

The extent to which biomarkers of asthma activity persist in spontaneous asthma remission and whether such markers are associated with future respiratory outcomes remained unclear. We investigated the association between sub-clinical inflammation in adults with spontaneous asthma remission and future asthma relapse and lung function decline.

METHODS

The Tasmanian Longitudinal Health Study is a population-based cohort (n = 8583). Biomarkers of systemic inflammation were measured on participants at age 45, and latent profile analysis was used to identify cytokine profiles. Bronchial hyperresponsiveness (BHR) and nitric oxide products in exhaled breath condensate (EBC NOx) were measured at age 50. Participants with spontaneous asthma remission at ages 45 (n = 466) and 50 (n = 318) were re-evaluated at age 53, and associations between baseline inflammatory biomarkers and subsequent asthma relapse and lung function decline were assessed.

RESULTS

We identified three cytokine profiles in adults with spontaneous asthma remission: average (34%), Th2-high (42%) and Th2-low (24%). Compared to the average profile, a Th2-high profile was associated with accelerated decline in post-BD FEV1 /FVC (MD -0.18% predicted per-year; 95% CI -0.33, -0.02), while a Th2-low profile was associated with accelerated decline in both post-BD FEV1 (-0.41%; -0.75, -0.06) and post-BD FVC (-0.31%; -0.62, 0.01). BHR and high TNF-α during spontaneous remission were associated with an increased risk of asthma relapse. In contrast, we found no evidence of association between EBC NOx and either asthma relapse or lung function decline.

CONCLUSION

BHR and serum inflammatory cytokines have prognostic value in adults with spontaneous asthma remission. At-risk individuals with BHR, Th2-high or Th2-low cytokine profiles may benefit from closer monitoring and on-going follow-up.

Exhaled nitric oxide in asthma: from diagnosis to management

PURPOSE OF REVIEW

Exhaled nitric oxide (FENO) is a noninvasive marker of eosinophilic airway inflammation, therefore, highly informative in asthma. Although FENO measurement is a potentially accessible tool to many physicians, recommendations regarding its clinical utility in diagnosing or tailoring treatment have not reached the expected diffusion. More recently FENO emerged as a biomarker for type-2 asthma phenotyping and a predictor of response to biologics.

RECENT FINDINGS

The physiological discoveries and relevant acquisitions in clinical practice regarding FENO in asthma are presented. The FENO story draw a wavy path, characterized by promising findings, exciting confirmations and periods of low visibility. FENO emerged as a tool to increase the probability of asthma diagnosis. FENO predicts response to inhaled glucocorticoids (ICS), favoring the development of tailored treatment strategies and unrevealing nonadherence to ICS in difficult-to-treat or uncontrolled asthma. Finally, FENO was associated with a more severe phenotype and became a consolidated biomarker of type-2 inflammation.

SUMMARY

FENO demonstrated to be a noninvasive and very reproducible test, encompassing many applications in the field of asthma management. Its routinely use, according to international guidelines, may improve the quality of patient assistance, from difficult-to-treat cases to biologic monitoring.

A2BCD: a concise guide for asthma management

The management of asthma has changed fundamentally during the past two decades. Precise assessment and phenotyping are now required to establish individually targeted treatment with disease-modifying anti-asthmatic drugs (DMAADs). Patients with asthma are often managed by primary care doctors or non-respiratory specialists in secondary care. However, the implementation of complex asthma guidelines in non-specialised care remains a challenge. There is a need for easy-to-understand, concise guides for general practice. In this Viewpoint, we propose a one-page practical guide for asthma management, titled A²BCD, with four components: dual assessment (A²) of asthma (ie, diagnosis and phenotype, plus asthma control and future risks); basic measures (B; eg, education, self-management skills, regular physical activity, and avoidance of asthma triggers); identification and treatment of comorbidities (C) of asthma (eg, chronic rhinosinusitis, obesity, or sleep apnoea); and phenotype-specific, individually targeted treatment with DMAADs (D), including individual inhalation schemes based on inhaled corticosteroids, leukotriene modifiers, biologics, and allergen immunotherapy.

Different aspects of severe asthma in real life: Role of Staphylococcus aureus enterotoxins and correlation to comorbidities and disease severity

BACKGROUND

Asthma, with several phenotypes and endotypes, is considered particularly suited for precision medicine. The identification of different non-invasive biomarkers may facilitate diagnosis and treatment. Recently, Staphylococcus aureus and its enterotoxins (SE) have been found to have a role in inducing persistent type 2 airway inflammation in severe asthma, but also in such comorbidities as chronic rhinosinusitis with nasal polyposis (CRSwNP).

METHODS

The aim of this retrospective study was to evaluate the prevalence of SE-IgE sensitization in a multicentric Italian cohort of severe asthmatic patients and correlate it with demographic and clinical characteristics.

RESULTS

A total of 249 patients were included in the analysis, out of which 25.3% were staphylococcal enterotoxin B (SEB)-IgE positive. We found a meaningful association between SEB-IgE and female gender, a positive association was also measured between CRS and CRSwNP. No significant association was found between SEB-IgE sensitization and atopy, the occurrence of exacerbations and corticosteroid dosages. In the SEB-IgE-positive patient, blood eosinophil count does not appear to be correlated with the severity of the disease. Patients with SEB-IgE sensitization are, on average, younger and with an earlier disease onset, thus confirming the possibility to consider SEB-IgE sensitization as an independent risk factor for developing asthma.

CONCLUSIONS

Our data confirm that the search for SE in the initial screening phase of these patients is helpful to better phenotype them, may predict the evolution of comorbidities and lead to a targeted therapeutic choice; in this point of view this represents a goal of precision medicine.

Differences Between Early- and Late-Onset Asthma: Role of Comorbidities in Symptom Control

BACKGROUND

Asthma can present in early childhood or de novo in adulthood. Our understanding of the burden of comorbidities in adult asthmatic patients stratified by age at onset is incomplete.

OBJECTIVES

To evaluate how different comorbidities may affect symptom control in two distinct groups of patients with early- and late-onset asthma (EOA and LOA, respectively) and to explore whether reported comorbidities are associated with lung function and inflammatory parameters.

METHODS

We conducted a cross-sectional study of 175 adult asthmatic patients (aged 57.5 ± 17.1 years) recruited at our university asthma clinic. We defined EOA as asthma onset less than 12 years, and LOA as onset greater than 40 years. The primary outcome was symptom control and main comorbidities evaluated were rhinitis, gastroesophageal reflux, obesity, cardiovascular conditions, and bronchiectasis. We used multivariable regression analysis to identify potential predictors of poor control in EOA and LOA.

RESULTS

Of 175 subjects, 77 had EOA (44%), 98 had LOA (56%), and comorbidities had a differential impact in the two groups. Rhinitis was more frequent in EOA (76 vs 53%; P = .02) and was associated with uncontrolled asthma (P < .001), reduced FEV₁/FVC (P = .01), increased eosinophils (P = .003) and total IgE (P < .01). Conversely, in LOA, rhinitis was associated with more controlled asthma and higher FEV₁/FVC (both P < .01). In EOA, only, IgE levels were directly related to blood eosinophils (r = 0.42; P <.001) and inversely to FEV₁/FVC (r = -0.35; P = .002). Obesity was present in 20% of patients in both groups, but only in LOA was it associated with uncontrolled disease (P = .009), reduced FEV₁/FVC (P = .009), and blood neutrophils (P = .03). In multivariable regression analysis, rhinitis in EOA and obesity in LOA were the risk factors most closely associated with poor control. Gastroesophageal reflux, cardiovascular comorbidities, and bronchiectasis did not affect control.

CONCLUSIONS

Early-onset persistent asthma and late-onset asthma are distinct phenotypes with different underlying inflammatory patterns and different comorbidities affecting symptom control.

Predictors of Low and High Exhaled Nitric Oxide Values in Asthma: A Real-World Study

BACKGROUND

In asthma, exhaled nitric oxide (FENO) is a clinically established biomarker of airway T2 inflammation and an indicator for anti-inflammatory therapy.

OBJECTIVES

The aim of the study was to identify, in an observational real-world cross-sectional study, the main characteristics of patients with asthma as classified by their FENO level.

METHOD

We stratified 398 patients with stable mild-to-severe asthma according to FENO level as low (≤25 ppb) versus elevated (>25 ppb), subdividing the latter into two subgroups: moderately elevated (26-50 ppb) versus very high FENO (>50 ppb). Clinical, functional, and blood parameters were extrapolated from patients' chart data and compared with the FENO stratification. Predictors of low and elevated FENO asthma were detected by logistic regression model.

RESULTS

Low BMI, higher blood eosinophilia, allergen poly-sensitization, the severest airflow obstruction (FEV1/FVC), and anti-leukotriene use are predictors of elevated FENO values in asthma, as well as persistent rhinitis and chronic rhinosinusitis with or without nasal polyps. Beyond these, younger age, more than 2 asthma exacerbations/year, higher airflow reversibility (post-bronchodilator ∆FEV1), and oral corticosteroid dependence are predictors of very high FENO values. In contrast, obesity, obstructive sleep apnoea syndrome, gastroesophageal reflux disease, arterial hypertension, and myocardial infarction are predictors of low FENO asthma. In our population, FENO correlated with blood eosinophils, airflow obstruction, and reversibility and negatively correlated with age and BMI.

CONCLUSIONS

Stratifying patients by FENO level can identify specific asthma phenotypes with distinct clinical features and predictors useful in clinical practice to tailor treatment and improve asthmatic patients' outcomes.

IgE is associated with exacerbations and lung function decline in COPD

Background

Both allergen-specific IgE and total IgE in serum play a major role in asthma. However, the role of IgE in chronic obstructive pulmonary disease (COPD) is poorly understood. It was the aim of this study to systematically analyze the relationship between serum IgE levels and disease characteristics in large COPD cohorts.

Methods

COSYCONET is a comprehensively characterized cohort of patients with COPD: total IgE and IgE specific to common aeroallergens were measured in serum of 2280 patients, and related to clinical characteristics of the patients. WISDOM is another large COPD population (2477 patients): this database contains the information whether total IgE in serum was elevated (≥ 100 IU/l) or normal in patients with COPD.

Results

Both in COSYCONET and WISDOM, total IgE was elevated (≥ 100 IU/l) in > 30% of the patients, higher in men than in women, and higher in currently than in not currently smoking men. In COSYCONET, total IgE was elevated in patients with a history of asthma and/or allergies. Men with at least one exacerbation in the last 12 months (50.6% of all men in COSYCONET) had higher median total IgE (71.3 IU/l) than men without exacerbations (48.3 IU/l): this difference was also observed in the subgroups of not currently smoking men and of men without a history of asthma. Surprisingly, a history of exacerbations did not impact on total IgE in women with COPD. Patients in the highest tertiles of total IgE (> 91.5 IU/ml, adjusted OR: 1.62, 95% CI 1.12–2.34) or allergen-specific IgE (> 0.19 IU/ml, adjusted OR: 2.15, 95% CI 1.32–3.51) were at risk of lung function decline (adjusted by: age, gender, body mass index, initial lung function, smoking status, history of asthma, history of allergy).

Conclusion

These data suggest that IgE may play a role in specific COPD subgroups. Clinical trials using antibodies targeting the IgE pathway (such as omalizumab), especially in men with recurrent exacerbations and elevated serum IgE, could elucidate potential therapeutic implications of our observations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01847-0.