Tracing the path from preschool wheezing to asthma.

This short review illustrates, using two recent studies, the potential and challenges of using machine learning methods to identify phenotypes of wheezing and asthma from childhood onwards.

Whole Exome Sequencing Identifies Epithelial and Immune Dysfunction-Related Biomarkers in Food Protein-Induced Enterocolitis Syndrome.

BACKGROUND: Food protein-induced enterocolitis syndrome (FPIES) is a food allergy primarily affecting infants, often leading to vomiting and shock. Due to its poorly understood pathophysiology and lack of specific biomarkers, diagnosis is frequently delayed. Understanding FPIES genetics can shed light on disease susceptibility and pathophysiology-key to developing diagnostic, prognostic, preventive and therapeutic strategies. Using a well-characterised cohort of patients we explored the potential genome-wide susceptibility factors underlying FPIES. METHODS: Blood samples from 41 patients with oral food challenge-proven FPIES were collected for a comprehensive whole exome sequencing association study. RESULTS: Notable genetic variants, including rs872786 (RBM8A), rs2241880 (ATG16L1) and rs2289477 (ATG16L1), were identified as significant findings in FPIES. A weighted SKAT model identified six other associated genes including DGKZ and SIRPA. DGKZ induces TGF-ß signalling, crucial for epithelial barrier integrity and IgA production; RBM8A is associated with thrombocytopenia absent radius syndrome, frequently associated with cow's milk allergy; SIRPA is associated with increased neutrophils/monocytes in inflamed tissues as often observed in FPIES; ATG16L1 is associated with inflammatory bowel disease. Coexpression correlation analysis revealed a functional correlation between RBM8A and filaggrin gene (FLG) in stomach and intestine tissue, with filaggrin being a known key pathogenic and risk factor for IgE-mediated food allergy. A transcriptome-wide association study suggested genetic variability in patients impacted gene expression of RBM8A (stomach and pancreas) and ATG16L1 (transverse colon). CONCLUSIONS: This study represents the first case-control exome association study of FPIES patients and marks a crucial step towards unravelling genetic susceptibility factors underpinning the syndrome. Our findings highlight potential factors and pathways contributing to FPIES, including epithelial barrier dysfunction and immune dysregulation. While these results are novel, they are preliminary and need further validation in a second cohort of patients.

Remote Assessment of Eczema Severity via AI-powered Skin Image Analytics: A Systematic Review.

Various studies have been published on the remote assessment of eczema severity from digital camera images. Successful deployment of an accurate and robust AI-powered tool for such purposes can aid the formulation of eczema treatment plans and assist in patient monitoring. This review aims to provide an overview of the quality of published studies on this topic and to identify challenges and suggestions to improve the robustness and reliability of existing tools. We identified 25 articles from the Scopus database that aimed to assess eczema severity automatically from digital camera images by eczema area detection (n=13), which is important for prior delineation of the most relevant clinical features, and/or severity prediction (n=12). Deep learning methods (n=14) were more commonly used in recent years over conventional machine learning (n=11). A set of 20 pre-defined criteria were used for critical appraisal in this study. Study quality was hindered in many cases due to dataset challenges, with only 28% of studies reporting patient age range and 16% reporting skin phototype range. Furthermore, 52% of studies utilised solely non-public datasets and only 17% provided open-source access to code repositories, making validation of experimental results a significant challenge. In terms of algorithm design, attempts to improve model accuracy and process automation are widely reported. However, there remains limited implementation of methods for explicitly improving model trustworthiness and robustness. There is a need for a high-quality dataset with a sufficient number of bias-free images and consistent labels, as well as improved image analytics methods, to enhance the state of remote eczema severity assessment algorithms. Improving the interpretability and explainability of developed tools will further improve long-term reliability and trustworthiness.

Deep multiomic profiling reveals molecular signatures that underpin preschool wheeze and asthma.

BACKGROUND: Wheezing in childhood is prevalent, with over one-half of all children experiencing at least 1 episode by age 6. The pathophysiology of wheeze, especially why some children develop asthma while others do not, remains unclear. OBJECTIVES: This study addresses the knowledge gap by investigating the transition from preschool wheeze to asthma using multiomic profiling. METHODS: Unsupervised, group-agnostic integrative multiomic factor analysis was performed using host/bacterial (meta)transcriptomic and bacterial shotgun metagenomic datasets from bronchial brush samples paired with metabolomic/lipidomic data from bronchoalveolar lavage samples acquired from children 1-17 years old. RESULTS: Two multiomic factors were identified: one characterizing preschool-aged recurrent wheeze and another capturing an inferred trajectory from health to wheeze and school-aged asthma. Recurrent wheeze was driven by type 1-immune signatures, coupled with upregulation of immune-related and neutrophil-associated lipids and metabolites. Comparatively, progression toward asthma from ages 1 to 18 was dominated by changes related to airway epithelial cell gene expression, type 2-immune responses, and constituents of the airway microbiome, such as increased Haemophilus influenzae. CONCLUSIONS: These factors highlighted distinctions between an inflammation-related phenotype in preschool wheeze, and the predominance of airway epithelial-related changes linked with the inferred trajectory toward asthma. These findings provide insights into the differential mechanisms driving the progression from wheeze to asthma and may inform targeted therapeutic strategies.

Time trends in the epidemiology of food allergy in England: an observational analysis of Clinical Practice Research Datalink data.

BACKGROUND: Estimates for the prevalence of food allergy vary widely, with a paucity of data for adults. The aim of this analysis was to report trends in the incidence and prevalence of food allergy in England, using a national primary care dataset. METHODS: We analysed data from Clinical Practice Research Datalink between 1998 and 2018, with linked data to relevant hospital encounters in England. The main outcomes were incidence and prevalence of food allergy, according to three definitions of food allergy: possible food allergy, probable food allergy, and probable food allergy with adrenaline autoinjectors prescription. We also evaluated the difference in proportion of patients prescribed adrenaline autoinjectors by English Index of Multiple Deprivation (IMD), age, and by previous food anaphylaxis, and explored differences in patient encounters (general practice vs emergency department setting). FINDINGS: 7 627 607 individuals in the dataset were eligible for inclusion, of whom 150 018 (median age 19 years [IQR 4-34]; 82 614 [55·1%] female and 67 404 [44·9%] male) had a possible food allergy. 121 706 met diagnostic criteria for probable food allergy, of whom 38 288 were prescribed adrenaline autoinjectors. Estimated incidence of probable food allergy doubled between 2008 and 2018, from 75·8 individuals per 100 000 person-years (95% CI 73·7-77·9) in 2008 to 159·5 (156·6-162·3) individuals per 100 000 person-years in 2018. Prevalence increased from 0·4% (23 399 of 6 432 383) to 1·1% (82 262 of 7 627 607) over the same period and was highest in children under 5 years (11 951 [4·0%] of 296 406 in 2018) with lower prevalence in school-aged children (from 11 353 [2·4%] of 473 597 in 2018 for children aged 5-9 years to 6896 [1·7%] of 404 525 for those aged 15-19 years) and adults (42 848 [0·7%] of 5 992 454 in 2018). In those with previous food anaphylaxis, only 2321 (58·3%) of 3980 (975 [64·0%] of 1524 children and young people and 1346 [54·8%] of 2456 adults) had a prescription for adrenaline autoinjector. Adrenaline autoinjectors prescription was less common in those resident in more deprived areas (according to IMD). In the analysis of health-care encounters, 488 604 (97·1%) of 503 198 visits recorded for food allergy occurred in primary care, with 115 655 (88·4%) of 130 832 patients managed exclusively in primary care. INTERPRETATION: These estimates indicate an important and increasing burden of food allergy in England. Our findings that most patients with food allergy are managed outside the hospital system, with low rates of adrenaline autoinjector prescription in those with previous anaphylaxis, highlight a need to better support those working in primary care to ensure optimal management of patients with food allergy. FUNDING: UK Food Standards Agency and UK Medical Research Council.

Trajectories of egg sensitization in childhood: Two birth cohorts in Asia and Europe.

BACKGROUND: Hen's egg exposure through impaired skin barrier is considered a major mechanism of sensitization to eggs. However, the impact of filaggrin (FLG) gene loss-of-function mutations on the natural history of egg sensitization lacks consensus among studies. OBJECTIVE: To evaluate the association between the natural course of egg sensitization and FLG mutations. METHODS: We used Japanese and the UK birth cohorts (CHIBA and MAAS) to identify the longitudinal patterns of egg sensitization until mid-school age and examined the relationship between the identified patterns and FLG mutations. Sensitization was assessed using egg white-specific IgE levels or skin prick tests (SPTs). Egg allergy was confirmed by parental reports and sensitization. Latent class growth analysis identified longitudinal patterns. RESULTS: Three similar patterns of egg sensitization (persistent, early-onset remitting, and no/low grade classes) were identified in both cohorts, with differing prevalence estimates. The proportion of children with egg allergy in the persistent class at 7 or 8 years of age was 23% (CHIBA) and 20% (MAAS). Consistently in both cohorts, FLG mutations were significantly associated only with the persistent class. Children with FLG mutations had an approximately four-fold increased risk of being in the persistent sensitization class (RRRs: 4.3, 95%C.I. (1.2-16.0), p = .03 in CHIBA; 4.3 (1.3-14.7), p = .02 in MAAS). CONCLUSION: FLG loss-of-function mutations are associated with persistent egg sensitization in both Japanese and European ethnicities, and the mutations might be a potential biomarker for identifying the risk of persistent egg sensitization/allergy in early infancy. Future studies should incorporate oral food challenges to confirm this relationship.

Pediatric asthma comorbidities: Global impact and unmet needs.

Real-world data on the range and impact of comorbid health conditions that affect pediatric asthma are scant, especially from developing countries. Lack of data hinders effective diagnosis, treatment, and overall management of these complex cases. We, hereby, describe the common pediatric asthma comorbid conditions in terms of evidence for association, potential mechanisms of impact on asthma control, and treatment benefit. Obesity, upper airway allergies, dysfunctional breathing, multiple sensitizations, depressive disorders, food allergy, and gastro-esophageal reflux are common associations with difficult-to-treat asthma. On the other hand, asthma symptoms and/or management may negatively impact the well-being of children through drug adverse effects, worsening of anaphylaxis symptoms, and disturbing mental health. Awareness of these ailments may be crucial for designing the optimum care for each asthmatic child individually and may ultimately improve the quality of life of patients and their families. A multidisciplinary team of physicians is required to identify and manage such comorbidities aiming to mitigate the over-use of asthma pharmacotherapy. Asthma research should target relevant real-world difficulties encountered at clinical practice and focus on interventions that would mitigate the impact of such comorbidities. Finally, policymakers and global healthcare organizations are urged to recognize pediatric asthma control as a healthcare priority and allocate resources for research and clinical interventions. In other words, global asthma control needs support by compassionate scientific partnership.

Parent's perception of respiratory syncytial virus and subsequent wheezing burden: A multi-country cross-sectional survey.

BACKGROUND: Respiratory Syncytial Virus (RSV) is the leading cause of hospitalization in infants. RSV bronchiolitis is associated with an increased risk of subsequent wheezing. We aimed to document the parents' perception of the link between RSV infection and subsequent wheezing, wheezing-related healthcare and family resources use, and its impact on family daily life. METHODS: This cross-sectional online survey enrolled 1200 parents with at least one child ≤6y living in the United States, United Kingdom, Spain, and Italy. Children diagnosed with RSV bronchiolitis before age of 2 years were included in the RSV group, and those never diagnosed with RSV bronchiolitis in the Reference group. RESULTS: The odds of wheezing were 4.5-fold (95%CI 3.5-5.9) higher in the RSV than in the Reference group. The odds increased to 7.7-fold (95%CI 5.4-11.1) among children who were hospitalized, and 9-fold (95%CI 5.1-16.6) among those admitted to pediatric intensive care with RSV bronchiolitis. Similar trends were observed across all countries. In total, 57% of parents reported their child's wheezing to have moderate to severe impact on their emotional well-being, and 53% on their daily life activities and/or social life. 64% of parents reported moderate-severe impact of wheezing on child's quality of sleep and 49% and 46% reported a moderate-severe impact on their children's emotional well-being and physical activities. CONCLUSIONS: This survey suggests an association between RSV infection and subsequent wheezing in children across different countries. Wheezing, especially in association with RSV infection, was associated with increased healthcare utilization and costs, and significantly impacted parents' and children daily life.

European Respiratory Society statement on preschool wheezing disorders: updated definitions, knowledge gaps and proposed future research directions.

Since the publication of the European Respiratory Society (ERS) task force reports on the management of preschool wheezing in 2008 and 2014, a large body of evidence has accumulated suggesting that the clinical phenotypes that were proposed (episodic (viral) wheezing and multiple-trigger wheezing) do not relate to underlying airway pathology and may not help determine response to treatment. Specifically, using clinical phenotypes alone may no longer be appropriate, and new approaches that can be used to inform clinical care are needed for future research. This ERS task force reviewed the literature published after 2008 related to preschool wheezing and has suggested that the criteria used to define wheezing disorders in preschool children should include age of diagnosis (0 to <6 years), confirmation of wheezing on at least one occasion, and more than one episode of wheezing ever. Furthermore, diagnosis and management may be improved by identifying treatable traits, including inflammatory biomarkers (blood eosinophils, aeroallergen sensitisation) associated with type-2 immunity and differential response to inhaled corticosteroids, lung function parameters and airway infection. However, more comprehensive use of biomarkers/treatable traits in predicting the response to treatment requires prospective validation. There is evidence that specific genetic traits may help guide management, but these must be adequately tested. In addition, the task force identified an absence of caregiver-reported outcomes, caregiver/self-management options and features that should prompt specialist referral for this age group. Priorities for future research include a focus on identifying 1) mechanisms driving preschool wheezing; 2) biomarkers of treatable traits and efficacy of interventions in those without allergic sensitisation/eosinophilia; 3) the need to include both objective outcomes and caregiver-reported outcomes in clinical trials; 4) the need for a suitable action plan for children with preschool wheezing; and 5) a definition of severe/difficult-to-treat preschool wheezing.

Lung function trajectories from school age to adulthood and their relationship with markers of cardiovascular disease risk.

RATIONALE: Lung function in early adulthood is associated with subsequent adverse health outcomes. OBJECTIVES: To ascertain whether stable and reproducible lung function trajectories can be derived in different populations and investigate their association with objective measures of cardiovascular structure and function. METHODS: Using latent profile modelling, we studied three population-based birth cohorts with repeat spirometry data from childhood into early adulthood to identify trajectories of forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC). We used multinomial logistic regression models to investigate early-life predictors of the derived trajectories. We then ascertained the extent of the association between the derived FEV1/FVC trajectories and blood pressure and echocardiographic markers of increased cardiovascular risk and stroke in ~3200 participants at age 24 years in one of our cohorts. RESULTS: We identified four FEV1/FVC trajectories with strikingly similar latent profiles across cohorts (pooled N=6377): above average (49.5%); average (38.3%); below average (10.6%); and persistently low (1.7%). Male sex, wheeze, asthma diagnosis/medication and allergic sensitisation were associated with trajectories with diminished lung function in all cohorts. We found evidence of an increase in cardiovascular risk markers ascertained by echocardiography (including left ventricular mass indexed to height and carotid intima-media thickness) with decreasing FEV1/FVC (with p values for the mean crude effects per-trajectory ranging from 0.10 to p<0.001). In this analysis, we considered trajectories as a pseudo-continuous variable; we confirmed the assumption of linearity in all the regression models. CONCLUSIONS: Childhood lung function trajectories may serve as predictors in the development of not only future lung disease, but also the cardiovascular disease and multimorbidity in adulthood.

Determinants of lung function development from birth to age 5 years: an interrupted time series analysis of a South African birth cohort.

BACKGROUND: Early life is a key period that determines long-term health. Lung development in childhood predicts lung function attained in adulthood and morbidity and mortality across the life course. We aimed to assess the effect of early-life lower respiratory tract infection (LRTI) and associated risk factors on lung development from birth to school age in a South African birth cohort. METHODS: We prospectively followed children enrolled in a population-based cohort from birth (between March 5, 2012 and March 31, 2015) to age 5 years with annual lung function assessment. Data on multiple early-life exposures, including LRTI, were collected. The effect of early-life risk factors on lung function development from birth to age 5 years was assessed using the Generalised Additive Models for Location, Scale and Shape and Interrupted Time Series approach. FINDINGS: 966 children (475 [49·2%] female, 491 [50·8%] male) had lung function measured with oscillometry, tidal flow volume loops, and multiple breath washout. LRTI occurred in 484 (50·1%) children, with a median of 2·0 LRTI episodes (IQR 1·0-3·0) per child. LRTI was independently associated with altered lung function, as evidenced by lower compliance (0·959 [95% CI 0·941-0·978]), higher resistance (1·028 [1·016-1·041]), and higher respiratory rate (1·018 [1·063-1·029]) over 5 years. Additional impact on lung function parameters occurred with each subsequent LRTI. Respiratory syncytial virus (RSV) LRTI was associated with lower expiratory flow ratio (0·97 [0·95-0·99]) compared with non-RSV LRTI. Maternal factors including allergy, smoking, and HIV infection were also associated with altered lung development, as was preterm birth, low birthweight, female sex, and coming from a less wealthy household. INTERPRETATION: Public health interventions targeting LRTI prevention, with RSV a priority, are vital, particularly in low-income and middle-income settings. FUNDING: UK Medical Research Council Grant, The Wellcome Trust, The Bill & Melinda Gates Foundation, US National Institutes of Health Human Heredity and Health in Africa, South African Medical Research Council, Hungarian Scientific Research Fund, and European Respiratory Society.

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.

Component-specific clusters for diagnosis and prediction of allergic airway diseases.

BACKGROUND: Previous studies which applied machine learning on multiplex component-resolved diagnostics arrays identified clusters of allergen components which are biologically plausible and reflect the sources of allergenic proteins and their structural homogeneity. Sensitization to different clusters is associated with different clinical outcomes. OBJECTIVE: To investigate whether within different allergen component sensitization clusters, the internal within-cluster sensitization structure, including the number of c-sIgE responses and their distinct patterns, alters the risk of clinical expression of symptoms. METHODS: In a previous analysis in a population-based birth cohort, by clustering component-specific (c-s)IgEs, we derived allergen component clusters from infancy to adolescence. In the current analysis, we defined each subject's within-cluster sensitization structure which captured the total number of c-sIgE responses in each cluster and intra-cluster sensitization patterns. Associations between within-cluster sensitization patterns and clinical outcomes (asthma and rhinitis) in early-school age and adolescence were examined using logistic regression and binomial generalized additive models. RESULTS: Intra-cluster sensitization patterns revealed specific associations with asthma and rhinitis (both contemporaneously and longitudinally) that were previously unseen using binary sensitization to clusters. A more detailed description of the subjects' within-cluster c-sIgE responses in terms of the number of positive c-sIgEs and unique sensitization patterns added new information relevant to allergic diseases, both for diagnostic and prognostic purposes. For example, the increase in the number of within-cluster positive c-sIgEs at age 5 years was correlated with the increase in prevalence of asthma at ages 5 and 16 years, with the correlations being stronger in the prediction context (e.g. for the largest 'Broad' component cluster, contemporaneous: r = .28, p = .012; r = .22, p = .043; longitudinal: r = .36, p = .004; r = .27, p = .04). CONCLUSION: Among sensitized individuals, a more detailed description of within-cluster c-sIgE responses in terms of the number of positive c-sIgE responses and distinct sensitization patterns, adds potentially important information relevant to allergic diseases.

Association between polymorphisms on chromosome 17q12-q21 and rhinovirus-induced interferon responses.

BACKGROUND: Single nucleotide polymorphisms (SNPs) in genes on chromosome 17q12-q21 are associated with childhood-onset asthma and rhinovirus-induced wheeze. There are few mechanistic data linking chromosome 17q12-q21 to wheezing illness. OBJECTIVE: We investigated whether 17q12-q21 risk alleles were associated with impaired interferon responses to rhinovirus. METHODS: In a population-based birth cohort of European ancestry, we stimulated peripheral blood mononuclear cells with rhinovirus A1 (RV-A1) and rhinovirus A16 (RV-A16) and measured IFN and IFN-induced C-X-C motif chemokine ligand 10 (aka IP10) responses in supernatants. We investigated associations between virus-induced cytokines and 6 SNPs in 17q12-q21. Bayesian profile regression was applied to identify clusters of individuals with different immune response profiles and genetic variants. RESULTS: Five SNPs (in high linkage disequilibrium, r2 ≥ 0.8) were significantly associated with RV-A1-induced IFN-ß (rs9303277, P = .010; rs11557467, P = .012; rs2290400, P = .006; rs7216389, P = .008; rs8079416, P = .005). A reduction in RV-A1-induced IFN-ß was observed among individuals with asthma risk alleles. There were no significant associations for RV-A1-induced IFN-α or CXCL10, or for any RV-A16-induced IFN/CXCL10. Bayesian profile regression analysis identified 3 clusters that differed in IFN-ß induction to RV-A1 (low, medium, high). The typical genetic profile of the cluster associated with low RV-A1-induced IFN-ß responses was characterized by a very high probability of being homozygous for the asthma risk allele for all SNPs. Children with persistent wheeze were almost 3 times more likely to be in clusters with reduced/average RV-A1-induced IFN-ß responses than in the high immune response cluster. CONCLUSIONS: Polymorphisms on chromosome 17q12-q21 are associated with rhinovirus-induced IFN-ß, suggesting a novel mechanism-impaired IFN-ß induction-links 17q12-q21 risk alleles with asthma/wheeze.

Lung-function trajectories: relevance and implementation in clinical practice.

Lung development starts in utero and continues during childhood through to adolescence, reaching its peak in early adulthood. This growth is followed by gradual decline due to physiological lung ageing. Lung-function development can be altered by several host and environmental factors during the life course. As a result, a range of lung-function trajectories exist in the population. Below average trajectories are associated with respiratory, cardiovascular, metabolic, and mental health comorbidities, as well as with premature death. This Review presents progressive research into lung-function trajectories and assists the implementation of this knowledge in clinical practice as an innovative approach to detect poor lung health early, monitor respiratory disease progression, and promote lung health. Specifically, we propose that, similar to paediatric height and weight charts used globally to monitor children's growth, lung-function charts could be used for both children and adults to monitor lung health status across the life course. To achieve this proposal, we introduce our free online Lung Function Tracker tool. Finally, we discuss challenges and opportunities for effective implementation of the trajectory concept at population level and outline an agenda for crucial research needed to support such implementation.

Updated grading system for systemic allergic reactions: Joint Statement of the World Allergy Organization Anaphylaxis Committee and Allergen Immunotherapy Committee.

There is a lack of consensus over the description and severity assignment of allergic adverse reactions to immunotherapy, although there seems to be a consensus at least in terms of using the World Allergy Organization (WAO) grading systems to describe local adverse events for Sublingual Immunotherapy (SLIT) and Systemic Allergic Reactions (SARs) to Subcutaneous Immunotherapy (SCIT) amongst the major national/regional allergy societies. In this manuscript, we propose a modification of the previous WAO Grading system for SARs, which aligns with the newly-proposed Consortium for Food Allergy Research (CoFAR) Grading Scale for Systemic Allergic Reactions in Food Allergy (version 3.0). We hope this can facilitate a unified grading system appropriate to SARs due to allergen immunotherapy, independent of allergen and route of administration, and across clinical and research practice.

Understanding the heterogeneity of childhood allergic sensitization and its relationship with asthma.

PURPOSE OF REVIEW: To review the current state of knowledge on the relationship between allergic sensitization and asthma; to lay out a roadmap for the development of IgE biomarkers that differentiate, in individual sensitized patients, whether their sensitization is important for current or future asthma symptoms, or has little or no relevance to the disease. RECENT FINDINGS: The evidence on the relationship between sensitization and asthma suggests that some subtypes of allergic sensitization are not associated with asthma symptoms, whilst others are pathologic. Interaction patterns between IgE antibodies to individual allergenic molecules on component-resolved diagnostics (CRD) multiplex arrays might be hallmarks by which different sensitization subtypes relevant to asthma can be distinguished. These different subtypes of sensitization are associated amongst sensitized individuals at all ages, with different clinical presentations (no disease, asthma as a single disease, and allergic multimorbidity); amongst sensitized preschool children with and without lower airway symptoms, with different risk of subsequent asthma development; and amongst sensitized patients with asthma, with differing levels of asthma severity. SUMMARY: The use of machine learning-based methodologies on complex CRD data can help us to design better diagnostic tools to help practising physicians differentiate between benign and clinically important sensitization.

Obstructive and restrictive spirometry from school age to adulthood: three birth cohort studies.

Background: Spirometric obstruction and restriction are two patterns of impaired lung function which are predictive of poor health. We investigated the development of these phenotypes and their transitions through childhood to early adulthood. Methods: In this study, we analysed pooled data from three UK population-based birth cohorts established between 1989 and 1995. We applied descriptive statistics, regression modelling and data-driven modelling to data from three population-based birth cohorts with at least three spirometry measures from childhood to adulthood (mid-school: 8-10 years, n = 8404; adolescence: 15-18, n = 5764; and early adulthood: 20-26, n = 4680). Participants were assigned to normal, restrictive, and obstructive spirometry based on adjusted regression residuals. We considered two transitions: from 8-10 to 15-18 and from 15-18 to 20-26 years. Findings: Obstructive phenotype was observed in ∼10%, and restrictive in ∼9%. A substantial proportion of children with impaired lung function in school age (between one third in obstructive and a half in restricted phenotype) improved and achieved normal and stable lung function to early adulthood. Of those with normal lung function in school-age, <5% declined to adulthood. Underweight restrictive and obese obstructive participants were less likely to transit to normal. Maternal smoking during pregnancy and current asthma diagnosis increased the risk of persistent obstruction and worsening. Significant associate of worsening in restrictive phenotypes was lower BMI at the first lung function assessment. Data-driven methodologies identified similar risk factors for obstructive and restrictive clusters. Interpretation: The worsening and improvement in obstructive and restrictive spirometry were observed at all ages. Maintaining optimal weight during childhood and reducing maternal smoking during pregnancy may reduce spirometry obstruction and restriction and improve lung function. Funding: MRC Grant MR/S025340/1.

Evaluation of measurement errors in the Patient-Oriented Eczema Measure (POEM) outcome.

BACKGROUND: The Patient-Oriented Eczema Measure (POEM) is the recommended core outcome instrument for atopic dermatitis (AD) symptoms. POEM is reported by recalling the presence/absence of seven symptoms in the last 7 days. OBJECTIVE: To evaluate measurement errors in POEM recordings due to imperfect recall. METHODS: Using data from a clinical trial of 247 AD patients aged 12-65 years, we analysed the reported POEM score (r-POEM) and the POEM derived from the corresponding daily scores for the same seven symptoms without weekly recall (d-POEM). We quantified recall error by comparing the r-POEM and d-POEM for 777 patient-weeks collected from 207 patients, and estimated two components of recall error: (1) recall bias due to systematic errors in measurements and (2) recall noise due to random errors in measurements, using a bespoke statistical model. RESULTS: POEM scores have a relatively low recall bias, but a high recall noise. Recall bias was estimated at 1.2 points lower for the r-POEM on average than the d-POEM, with a recall noise of 5.7 points. For example, a patient with a recall-free POEM of 11 (moderate) could report their POEM score anywhere from 5 to 14 (with 95% probability) because of recall error. Model estimates suggested that patients tend to recall itch and dryness more often than experienced (positive bias of less than 1 day), but less often for the other symptoms (bleeding, cracking, flaking, oozing/weeping and sleep disturbance; negative bias ranging 1-4 days). CONCLUSIONS: In this clinical trial data set, we found that patients tended to slightly underestimate their symptoms when reporting POEM, with significant variation in how well they were able to recall the frequency of their symptoms every time they reported POEM. A large recall noise should be taken into consideration when interpreting POEM scores.