Heterogeneity of Childhood Asthma in Korea: Cluster Analysis of the Korean Childhood Asthma Study Cohort

Artificial intelligence in pediatric allergy research

Atopic dermatitis, food allergy, allergic rhinitis, and asthma are among the most common diseases in childhood. They are heterogeneous diseases, can co-exist in their development, and manifest complex associations with other disorders and environmental and hereditary factors. Elucidating these intricacies by identifying clinically distinguishable groups and actionable risk factors will allow for better understanding of the diseases, which will enhance clinical management and benefit society and affected individuals and families. Artificial intelligence (AI) is a promising tool in this context, enabling discovery of meaningful patterns in complex data. Numerous studies within pediatric allergy have and continue to use AI, primarily to characterize disease endotypes/phenotypes and to develop models to predict future disease outcomes. However, most implementations have used relatively simplistic data from one source, such as questionnaires. In addition, methodological approaches and reporting are lacking. This review provides a practical hands-on guide for conducting AI-based studies in pediatric allergy, including (1) an introduction to essential AI concepts and techniques, (2) a blueprint for structuring analysis pipelines (from selection of variables to interpretation of results), and (3) an overview of common pitfalls and remedies. Furthermore, the state-of-the art in the implementation of AI in pediatric allergy research, as well as implications and future perspectives are discussed.

CONCLUSION

AI-based solutions will undoubtedly transform pediatric allergy research, as showcased by promising findings and innovative technical solutions, but to fully harness the potential, methodologically robust implementation of more advanced techniques on richer data will be needed.

WHAT IS KNOWN

• Pediatric allergies are heterogeneous and common, inflicting substantial morbidity and societal costs. • The field of artificial intelligence is undergoing rapid development, with increasing implementation in various fields of medicine and research.

WHAT IS NEW

• Promising applications of AI in pediatric allergy have been reported, but implementation largely lags behind other fields, particularly in regard to use of advanced algorithms and non-tabular data. Furthermore, lacking reporting on computational approaches hampers evidence synthesis and critical appraisal. • Multi-center collaborations with multi-omics and rich unstructured data as well as utilization of deep learning algorithms are lacking and will likely provide the most impactful discoveries.

Fetal growth rather than prematurity determines lung function in children with asthma

BACKGROUND AND OBJECTIVE

Preterm birth or fetal growth has been associated with reduced lung function and asthma during childhood in the general population. We aimed to elucidate whether prematurity or fetal growth has a significant influence on lung function or symptoms in children with stable asthma.

METHODS

We included children with stable asthma who participated in the Korean childhood Asthma Study cohort. Asthma symptoms were determined by asthma control test (ACT). Percent predicted values of pre- and post-bronchodilator (BD) lung function including forced expiratory volume in 1 second (FEV1 ), forced vital capacity (FVC), and forced expiratory flow at 25%-75% of FVC (FEF25%-75% ) were measured. Lung function and symptoms were compared according to the history of preterm birth and birth weight (BW) for gestational age (GA).

RESULTS

The study population consisted of 566 children (age range: 5-18 years). There were no significant differences in lung function and ACT between preterm and term subjects. We observed no significant difference in ACT but significant differences were observed in pre- and post-BD FEV1 , pre- and post-BD FVC, and post-BD FEF25%-75% according to BW for GA in total subjects. Two-way ANOVA revealed that BW for GA rather than prematurity was a significant determining factor for pre- and post-BD lung function. After regression analysis, BW for GA was still a significant determining factor of pre- and post-BD FEV1 and pre- and post-BD FEF25%-75% .

CONCLUSION

Fetal growth rather than prematurity appears to have a significant effect on lung function in children with stable asthma.

Childhood asthma phenotypes and endotypes: a glance into the mosaic

BACKGROUND

Asthma is an inflammatory lung disease that constitutes the most common noncommunicable chronic disease in childhood. Childhood asthma shows large heterogeneity regarding onset of disease, symptoms, severity, prognosis, and response to therapy.

MAIN BODY

Evidence suggests that this variability is due to distinct pathophysiological mechanisms, which has led to an exhaustive research effort to understand and characterize these distinct entities currently designated as "endotypes." Initially, studies focused on identifying specific groups using clinical variables yielding different "clinical phenotypes." In addition, the identification of specific patterns based on inflammatory cell counts and cytokine data has resulted in "inflammatory endotypes." More recently, an increasing number of molecular data from high-throughput technology ("omics" data) have allowed to investigate more complex "molecular endotypes."

CONCLUSION

A better definition and comprehension of childhood asthma heterogeneity is key for improving diagnosis and treatment. This review aims at summarizing the current knowledge on this topic and discusses some limitations in their application as well as recommendations for future studies.

Sex Plays a Multifaceted Role in Asthma Pathogenesis

Sex is considered an important risk factor for asthma onset and exacerbation. The prevalence of asthma is higher in boys than in girls during childhood, which shows a reverse trend after puberty—it becomes higher in adult females than in adult males. In addition, asthma severity, characterized by the rate of hospitalization and relapse after discharge from the emergency department, is higher in female patients. Basic research indicates that female sex hormones enhance type 2 adaptive immune responses, and male sex hormones negatively regulate type 2 innate immune responses. However, whether hormone replacement therapy in postmenopausal women increases the risk of current asthma and asthma onset remains controversial in clinical settings. Recently, sex has also been shown to influence the pathophysiology of asthma in its relationship with genetic or other environmental factors, which modulate asthmatic immune responses in the airway mucosa. In this narrative review, we highlight the role of sex in the continuity of the asthmatic immune response from sensing allergens to Th2 cell activation based on our own data. In addition, we elucidate the interactive role of sex with genetic or environmental factors in asthma exacerbation in women.

Longitudinal asthma exacerbation phenotypes in the Korean childhood asthma study cohort

BACKGROUND

Asthma exacerbation (AE) leads to social and economic costs and long-term adverse outcomes. We aimed to predict exacerbation-prone asthma (EPA) in children.

METHODS

The Korean childhood Asthma Study (KAS) is a prospective nationwide pediatric asthma cohort of children aged 5-15 years followed every 6 months. Patients with AE during the 6 months prior to all three visits, with AE prior to one or two visits, and without AE prior to any visit were defined as having EPA, exacerbation-intermittent asthma (EIA), and exacerbation-resistant asthma (ERA), respectively. Risk factors and prediction models of EPA were explored.

RESULTS

Of the 497 patients who completed three visits, 42%, 18%, and 15% had exacerbations prior to visits 1, 2, and 3 and 5%, 47%, and 48% had EPA, EIA, and ERA, respectively. Univariate and multivariable logistic regression revealed forced expiratory volume in 1 s (FEV1) z-score, forced vital capacity (FVC) z-score, white blood cell (WBC) count, and asthma control test (ACT) score as relevant EPA risk factors. The EPA prediction model comprised FVC z-score, WBC count, ACT score, sex, and parental education level (area under the receiver operating characteristic curve [AUROC] 0.841 [95% confidence interval (CI): 0.728-0.954]).

CONCLUSION

With appropriate management, AE decreases over time, but persistent AEs may occur. Apart from asthma control level, baseline lung function and WBC count predicted EPA.

Clinical Experience with Anti-IgE Monoclonal Antibody (Omalizumab) in Pediatric Severe Allergic Asthma-A Romanian Perspective

Background: Asthma is the most common chronic disease affecting children, with a negative impact on their quality of life. Asthma is often associated with comorbid allergic diseases, and its severity may be modulated by immunoglobulin E (IgE)-mediated allergen sensitization. Omalizumab is a humanized monoclonal anti-IgE antibody, the first biological therapy approved to treat patients aged ≥6 years with severe allergic asthma. The primary objective of our study was to investigate the efficacy and safety of Omalizumab in Romanian children with severe allergic asthma. Methods: In this observational real-life study, 12 children and adolescents aged 6 to 18 years (mean 12.4 years) with severe allergic asthma received Omalizumab as an add-on treatment. Asthma control, exacerbations, lung function, and adverse events were evaluated at baseline and after the first year of treatment. Results: We observed general improvement in total asthma symptom scores and reduction in the rate of exacerbation of severe asthma. Omalizumab treatment was associated with improvement in the measures of lung function, and no serious adverse reactions were reported. FEV1 improved significantly after one year of treatment with Omalizumab [ΔFEV1 (% pred.) = 18.3], and [similarly, ΔMEF50 (%) = 25.8]. The mean severe exacerbation rate of asthma decreased from 4.1 ± 2.8 to 1.15 ± 0.78 (p < 0.0001) during the year of treatment with Omalizumab. Conclusions: This study showed that Omalizumab can be an effective and safe therapeutic option for Romanian children and adolescents with severe allergic asthma, providing clinically relevant information on asthma control and exacerbation rate in children and adolescents. The results demonstrated the positive effect of Omalizumab in young patients with asthma, starting from the first year of treatment.

Establishing a patient registry study database of dust mite allergic asthma in children: design, methodology and preliminary exploration

Background

Asthma is a heterogeneous disease with different phenotypes, endotypes and responses to treatment. Dust mite allergic asthma (DMAA) is the most common type in children. Compared with randomized control trials, a patient registry study (PRS) can reflect the real physical condition and clinical diagnosis more comprehensively.

Methods

Children who visited the asthma clinic of the Children’s Hospital of Chongqing Medical University between August 2018 and August 2020, and met the inclusion criteria and also agreed to participate, were enrolled in the registry study. Clinical information, laboratory tests and peripheral blood samples were collected after informed consent was given by guardians.

Results

To date, 208 children have been enrolled in the patient registry database of DMAA. They are mainly male, with >50% having a history of allergic rhinitis, cesarean section, positive family history and passive smoking. Eosinophils and total immunoglobulin E levels were all significantly higher than normal. According to results for the childhood asthma control test (c-ACT) and ratio of forced expiratory volume in 1 s to predicted value after inhaled corticosteroid treatment, the uncontrolled group had higher hemoglobin (Hb) levels than the control group. The group exhibiting abnormal pulmonary function was older, and had longer disease duration, higher fractional exhaled nitric oxide and Hb than the group in which pulmonary function was restored.

Conclusions

We have preliminarily established a registered study database of children with DMAA. By cluster analysis and using blood samples, we can further study the different pathophysiological mechanisms in order to provide more individualized and targeted treatments for all children.