Lung function testing and inflammation markers for wheezing preschool children: A systematic review for the EAACI Clinical Practice Recommendations on Diagnostics of Preschool Wheeze

Economic evidence supports the cost savings of sputum eosinophil counts to guide the treatment of pediatrics patients with persistent asthma: implications for clinical practice guidelines in middle-income countries

BACKGROUND

Tailoring asthma interventions based on biomarkers could substantially impact the high cost associated with asthma morbidity. For policymakers, the main concern is the economic impact of adopting this technology, especially in developing countries. This study evaluates the budget impact of asthma management using sputum eosinophil counts in Colombia patients between 4 and 18 years of age.

METHODS

A budget impact analysis was performed to evaluate the potential financial impact of sputum eosinophil counts (EO). The study considered a 5-year time horizon and the Colombian National Health System perspective. The incremental budget impact was calculated by subtracting the cost of the new treatment, in which EO is reimbursed, from the cost of the conventional therapy without EO (management based on clinical symptoms (with or without spirometry/peak flow) or asthma guidelines (or both), for asthma-related). Univariate one-way sensitivity analyses were performed.

RESULTS

In the base-case analysis, the 5-year costs associated with EO and no-EO were estimated to be US$ 532.865.915 and US$ 540.765.560, respectively, indicating savings for Colombian National Health equal to US$ 7.899.645, if EO is adopted for the routine management of patients with persistent asthma. This result was robust in univariate sensitivity one-way analysis.

CONCLUSION

EO was cost-saving in guiding the treatment of patients between 4 and 18 years of age with persistent asthma. Decision-makers in our country can use this evidence to improve clinical practice guidelines, and it should be replicated to validate their results in other middle-income countries.

Impulse oscillometry bronchodilator response in preschool children

BACKGROUND

In preschoolers, performing an acceptable spirometry and measuring bronchodilator response (BDR) is challenging; in this context, impulse oscillometry (IOS) represents a valid alternative. However, more studies on the standardization of BDR for IOS in young children are required.

OBJECTIVE

The objective of the study was to identify optimal thresholds to define a positive BDR test with IOS in preschoolers with suspected asthma.

METHODS

Children aged 3-6 years with suspected asthma and their lung function investigated with both IOS and spirometry pre- and post-BDR were retrospectively analyzed. The spirometric BDR was defined as positive when the change of FEV1 was ≥12% or ≥200 mL. The oscillometric BDR was defined as positive in case of change of at least -40% in R5, +50% in X5, and -80% in AX.

RESULTS

Among 72 patients, 36 (age 5.2 ± 1 years; 64% boys) were selected for the subsequent analysis according to ATS/ERS quality criteria of measurements; specifically, 19 patients did not meet IOS and 36 did not meet spirometry criteria. The spirometric BDR was found positive in seven subjects (19.4%); conversely, a positive oscillometric BDR was identified in four patients (11.1%). No patient presented a positive BDR response with both methods. In IOS, the mean decrease in R5 and AX was 19.9% ± 10% and 44% ± 22.1%, and the mean increase in X5 was 23.3% ± 17.8%, respectively. A decrease in R5 of 25.7% (AUC 0.77, p = .03) and an increase in X5 of 25.7% (AUC 0.75, p = .04) showed the best combination of sensitivity and specificity to detect an increase of FEV1 ≥ 12% and/or ≥200 mL.

CONCLUSION

The IOS represents a valid alternative to spirometry to measure BDR in preschool children and should be the gold standard in this age group. We are considering a decrease of 26% in R5 and an increase of 26% in X5 as diagnostic threshold for BDR.

Recommendations for asthma monitoring in children: A PeARL document endorsed by APAPARI, EAACI, INTERASMA, REG, and WAO

Monitoring is a major component of asthma management in children. Regular monitoring allows for diagnosis confirmation, treatment optimization, and natural history review. Numerous factors that may affect disease activity and patient well-being need to be monitored: response and adherence to treatment, disease control, disease progression, comorbidities, quality of life, medication side-effects, allergen and irritant exposures, diet and more. However, the prioritization of such factors and the selection of relevant assessment tools is an unmet need. Furthermore, rapidly developing technologies promise new opportunities for closer, or even "real-time," monitoring between visits. Following an approach that included needs assessment, evidence appraisal, and Delphi consensus, the PeARL Think Tank, in collaboration with major international professional and patient organizations, has developed a set of 24 recommendations on pediatric asthma monitoring, to support healthcare professionals in decision-making and care pathway design.

25 Years of translational research in the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC)

The Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) mother-child cohorts have provided a foundation of 25 years of research on the origins, prevention, and natural history of childhood asthma and related disorders. COPSAC's approach is characterized by clinical translational research with longitudinal deep phenotyping and exposure assessments from pregnancy, in combination with multi-omic data layers and embedded randomized controlled trials. One trial showed that fish oil supplementation during pregnancy prevented childhood asthma and identified pregnant women with the highest benefits from supplementation, thereby creating the potential for personalized prevention. COPSAC revealed that airway colonization with pathogenic bacteria in early life is associated with an increased risk of asthma. Further, airway bacteria were shown to be a trigger of acute asthma-like symptoms, with benefit from antibiotic treatment. COPSAC identified an immature gut microbiome in early life as a risk factor for asthma and allergy and further demonstrated that asthma can be predicted by infant lung function. At a molecular level, COPSAC has identified novel susceptibility genes, early immune deviations, and metabolomic alterations associated with childhood asthma. Thus, the COPSAC research program has enhanced our understanding of the processes causing childhood asthma and has suggested means of personalized prevention and treatment.

Utility of biomarkers in the diagnosis and monitoring of asthmatic children

Asthma imposes a heavy morbidity burden during childhood; it affects over 10% of children in Europe and North America and it is estimated to exceed 400 million people worldwide by the year 2025. In clinical practice, diagnosis of asthma in children is mostly based on clinical criteria; nevertheless, assessment of both physiological and pathological processes through biomarkers, support asthma diagnosis, aid monitoring, and further lead to better treatment outcomes and reduced morbidity. Recently, identification and validation of biomarkers in pediatric asthma has emerged as a top priority across leading experts, researchers, and clinicians. Moreover, the implementation of non-invasive biomarkers for the assessment and monitoring of paediatric patients with asthma, has been prioritized; however, only a proportion of them are currently included in the clinical practise. Although, the use of non-invasive biomarkers is highly supported in recent asthma guidelines for documenting diagnosis and supporting monitoring of asthmatic patients, data on the Pediatric population are limited. In the present report, the Pediatric Asthma Committee of the World Allergy Organization (WAO), aims to summarize and discuss available data for the implementation of non-invasive biomarkers in the diagnosis and monitoring in children with asthma. Information on the most studied biomarkers, including spirometry, oscillometry, markers of allergic sensitization, fractional exhaled nitric oxide, and the most recent exhaled breath markers and "omic" approaches, will be reviewed. Practical limitations and considerations based on both experts' opinion and critical review of the literature, on the utility of all "well-known" and newly introduced non-invasive biomarkers will be presented. A critical commentary on biomarkers' use in diagnosing and monitoring asthma during the COVID-19 pandemic, cost and availability of biomarkers in different settings and in developing countries, the differences on the biomarkers use between Primary Practitioners, Pediatricians, and Specialists and their role on the longitudinal aspect of asthma is provided.

"Liquid biopsy" - extracellular vesicles as potential novel players towards precision medicine in asthma

Extracellular vesicles (EVs) have emerged as vital mediators in intracellular communication in the lung microenvironment. Environmental exposure to various triggers (e.g., viruses, allergens) stimulates the EV-mediated cascade of pro-inflammatory responses that play a key role in the asthma pathomechanism. This complex EV-mediated crosstalk in the asthmatic lung microenvironment occurs between different cell types, including airway epithelial cells and immune cells. The cargo composition of EVs mirrors hereby the type and activation status of the parent cell. Therefore, EVs collected in a noninvasive way (e.g., in nasal lavage, serum) could inform on the disease status as a "liquid biopsy", which is particularly important in the pediatric population. As a heterogeneous disease, asthma with its distinct endotypes and phenotypes requires more investigation to develop novel diagnostics and personalized case management. Filling these knowledge gaps may be facilitated by further EV research. Here, we summarize the contribution of EVs in the lung microenvironment as potential novel players towards precision medicine in the development of asthma. Although rapidly evolving, the EV field is still in its infancy. However, it is expected that a better understanding of the role of EVs in the asthma pathomechanism will open up new horizons for precision medicine diagnostic and therapeutic solutions.

Objective confirmation of asthma diagnosis, treatment adherence and patient outcomes in children and adolescents

AIM

The aim of this study was to investigate the diagnostic workup in children with asthma hypothesising that objective confirmation of the diagnosis is associated with improved treatment adherence and patient outcomes.

METHODS

We reviewed medical records of children aged 5-18 years diagnosed with asthma at the Department of Paediatric and Adolescent Medicine, Herlev-Gentofte Hospital, Denmark, in 2018. Objective confirmation of the diagnosis was based on either (1) lung function, (2) bronchodilator response, (3) bronchial hyperresponsiveness and/or (4) elevated FeNO and was associated with treatment adherence (proportion of days covered, PDC), lung function development and exacerbations during a two-year follow-up period.

RESULTS

A total of 88 children were included. Asthma was objectively confirmed in 67 (76%). Children with objective confirmation of the diagnosis were more likely to redeem short-acting beta-2-agonist prescriptions: at least once, aOR = 1.3 (95% CI, 1.1-13.1), p = 0.036, and were more adherent to inhaled corticosteroid treatment: PDC>80%, aOR = 10.4 (1.8-201.1), p = 0.033. Further, objective confirmation was associated with improved lung function and reduced bronchodilator response, but not with exacerbations.

CONCLUSION

Objective confirmation of the asthma diagnosis in children is associated with an increased treatment adherence and improved lung function, which underlines the importance of conducting objective tests in the diagnostic workup in paediatric asthma management.

Paediatric asthma - all that wheezes is not necessarily asthma - current diagnostic and management strategies

PURPOSE OF REVIEW

Asthma is a frequently encountered chronic medical condition encountered in paediatrics, affecting 7% of children under the age of 18 in the United States. Although asthma is one of the more common conditions that is associated with wheezing, there is a broad differential diagnosis to consider. The purpose of this review is to describe other causes of wheezing outside of asthma in a paediatric population and discuss diagnostic and management strategies to consider when evaluating a child or adolescent with wheezing.

RECENT FINDINGS

The characteristics of the wheezing along with other associated signs and symptoms can be helpful in narrowing the differential diagnosis. The age and the past medical history of the patient are also important aspects to consider when determining next steps in the evaluation and management of paediatric wheezing. In addition to considering other causes of wheezing, it is often necessary to assess for the presence of underlying asthma, and recently updated asthma guidelines from the National Heart, Lung and Blood Institute provide a graded review of various recommendations for making the diagnosis and managing asthma in the clinical setting.

SUMMARY

It is important to maintain a broad differential diagnosis when evaluating a paediatric patient with wheezing.

Small airway dysfunction is an independent dimension of wheezing disease in preschool children

BACKGROUND

Whether small airway dysfunction (SAD), which is prevalent in asthma, helps to characterize wheezing phenotypes is undetermined. The objective was to assess whether SAD parameters obtained from impedance measurement and asthma probability are linked.

METHODS

One hundred and thirty-nine preschool children (mean age 4.7 years, 68% boys) suffering from recurrent wheezing underwent impulse oscillometry that allowed calculating peripheral resistance and compliance of the respiratory system (markers of SAD) using the extended RIC model (central and peripheral resistance, inertance, and peripheral compliance). Children were classified using the probability-based approach of GINA guidelines (few, some, and most having asthma). A principal component analysis (PCA) that determined the dimensions of wheezing disease evaluated the links between SAD and asthma probability.

RESULTS

Forty-seven children belonged to the few, 28 to the some, and 64 to the most having asthma groups. Whereas their anthropometrics and measured parameters were similar, the most having asthma group exhibited the lowest mean value of airway inertance after bronchodilator probably due to airway inhomogeneities. PCA characterized four independent dimensions including a peripheral resistance (constituted by baseline peripheral compliance, Frs, R5Hz, R5-20Hz, X5Hz, and AX), a central resistance (baseline central resistance, R20Hz), anthropometrics (age and height), and asthma probability (wheezing patterns and therapeutic steps). Thus, PCA showed that the SAD markers were independent from clinical dimensions and were unable to differentiate wheezing phenotypes.

CONCLUSIONS

Lung function parameters obtained from impulse oscillometry and asthma probability were belonging to independent dimensions of the wheezing disease.