TSLP disease-associated genetic variants combined with airway TSLP expression influence asthma risk.

BACKGROUND: Thymic stromal lymphopoietin (TSLP) is an epithelial-derived cytokine important in initiation of allergic inflammation. Single nucleotide polymorphisms (SNPs) in TSLP are associated with asthma, yet studies have shown inconsistent associations between circulating TSLP and asthma. Studies that integrate the combined effects of TSLP genotype, TSLP mRNA, circulating TSLP levels, and asthma outcome are lacking. OBJECTIVES: This study sought to recruit a novel cohort based on asthma-relevant TSLP SNPs and determine their impact on TSLP mRNA expression and TSLP circulating protein levels, and their individual and combined effects on asthma. METHODS: This study developed an algorithm to prioritize TSLP SNPs and recruited 51 carriers and noncarriers based on TSLP genotypes. TSLP mRNA was quantified in nasal epithelial cells and circulating TSLP levels in plasma. This study determined the associations of defined TSLP risk genotypes and/or TSLP mRNA and protein levels with asthma. RESULTS: TSLP mRNA expression, but not circulating TSLP, was significantly increased in people who are asthmatic compared with in people who are nonasthmatic (P = .007; odds ratio, 1.44). Notably, 90% of children with the defined TSLP risk genotypes and high nasal TSLP mRNA expression (top tertile) had asthma compared with 40% of subjects without risk genotypes and with low TSLP expression (bottom tertile) (P = .024). No association between circulating TSLP and asthma was observed. CONCLUSIONS: Collectively, these data suggest childhood asthma is modified by the combined effects of TSLP genotype and TSLP expression in the nasal epithelium. The increased asthma risk likely manifests when genetic variation enables expression quantitative trait loci in the TSLP locus to elevate TSLP. It is important to consider both biomarkers when factoring asthma risk.

Longitudinal atopic dermatitis endotypes: An atopic march paradigm that includes Black children.

BACKGROUND: The atopic march has been studied mostly in White populations, biasing our current paradigms. OBJECTIVE: We sought to define the atopic march in Black and White children and explore mechanisms for racial differences. METHODS: Utilizing the Mechanisms of Progression of Atopic Dermatitis to Asthma in Children (MPAACH) cohort (n = 601), we assessed longitudinal sensitization, food allergy (FA), allergic rhinitis, risk of asthma development (through the Pediatric Asthma Risk Score), Scoring for Atopic Dermatitis (SCORAD), transepidermal water loss, skin filaggrin (FLG) expression, exposures, and genetic heritability to define AD progression endotypes in Black and White children. RESULTS: White MPAACH children were more likely to be sensitized to aero and food allergens (P = .0001) and over 3 times more likely to develop FA and/or allergic rhinitis (AR) without asthma risk (P < .0001). In contrast, Black children were over 6 times more likely to proceed to high asthma risk without FA, sensitization, or AR (P < .0001). White children had higher lesional and nonlesional transepidermal water loss (both P < .001) as well as decreased nonlesional keratinocyte FLG expression (P = .02). Black children had increased genetic heritability for asthma risk and higher rates of exposures to secondhand smoke and traffic-related air pollution. CONCLUSIONS: Black and White children with AD have distinct allergic trajectories defined by different longitudinal endotypes. Black children exhibit higher asthma risk despite a more intact skin barrier and less sensitization, FA, and AR. White children have less asthma risk, despite a more dysfunctional skin barrier, and more FA, AR, and sensitization. The observed racial differences are likely due in part to increased genetic heritability for asthma risk and harmful environmental exposures in Black children. Collectively, our findings provide a new paradigm for an atopic march that is inclusive of Black children.

Risk factors for SARS-CoV-2 infection and transmission in households with children with asthma and allergy: A prospective surveillance study.

BACKGROUND: Whether children and people with asthma and allergic diseases are at increased risk for severe acute respiratory syndrome virus 2 (SARS-CoV-2) infection is unknown. OBJECTIVE: Our aims were to determine the incidence of SARS-CoV-2 infection in households with children and to also determine whether self-reported asthma and/or other allergic diseases are associated with infection and household transmission. METHODS: For 6 months, biweekly nasal swabs and weekly surveys were conducted within 1394 households (N = 4142 participants) to identify incident SARS-CoV-2 infections from May 2020 to February 2021, which was the pandemic period largely before a vaccine and before the emergence of SARS-CoV-2 variants. Participant and household infection and household transmission probabilities were calculated by using time-to-event analyses, and factors associated with infection and transmission risk were determined by using regression analyses. RESULTS: In all, 147 households (261 participants) tested positive for SARS-CoV-2. The household SARS-CoV-2 infection probability was 25.8%; the participant infection probability was similar for children (14.0% [95% CI = 8.0%-19.6%]), teenagers (12.1% [95% CI = 8.2%-15.9%]), and adults (14.0% [95% CI = 9.5%-18.4%]). Infections were symptomatic in 24.5% of children, 41.2% of teenagers, and 62.5% of adults. Self-reported doctor-diagnosed asthma was not a risk factor for infection (adjusted hazard ratio [aHR] = 1.04 [95% CI = 0.73-1.46]), nor was upper respiratory allergy or eczema. Self-reported doctor-diagnosed food allergy was associated with lower infection risk (aHR = 0.50 [95% CI = 0.32-0.81]); higher body mass index was associated with increased infection risk (aHR per 10-point increase = 1.09 [95% CI = 1.03-1.15]). The household secondary attack rate was 57.7%. Asthma was not associated with household transmission, but transmission was lower in households with food allergy (adjusted odds ratio = 0.43 [95% CI = 0.19-0.96]; P = .04). CONCLUSION: Asthma does not increase the risk of SARS-CoV-2 infection. Food allergy is associated with lower infection risk, whereas body mass index is associated with increased infection risk. Understanding how these factors modify infection risk may offer new avenues for preventing infection.

Building a Population Representative Pediatric Biobank: Lessons Learned From the Greater Cincinnati Childhood Cohort.

Background: Biobanks can accelerate research by providing researchers with samples and data. However, hospital-based recruitment as a source for controls may create bias as who comes to the hospital may be different from the broader population. Methods: In an effort to broadly improve the quality of research studies and reduce costs and challenges associated with recruitment and sample collection, a group of diverse researchers at Cincinnati Children's Hospital Medical Center led an institution-supported initiative to create a population representative pediatric "Greater Cincinnati Childhood Cohort (GCC)." Participants completed a detailed survey, underwent a brief physician-led physical exam, and provided blood, urine, and hair samples. DNA underwent high-throughput genotyping. Results: In total, 1,020 children ages 3-18 years living in the 7 county Greater Cincinnati Metropolitan region were recruited. Racial composition of the cohort was 84% non-Hispanic white, 15% non-Hispanic black, and 2% other race or Hispanic. Participants exhibited marked demographic and disease burden differences by race. Overall, the cohort was broadly used resulting in publications, grants and patents; yet, it did not meet the needs of all potential researchers. Conclusions: Learning from both the strengths and weaknesses, we propose leveraging a community-based participatory research framework for future broad use biobanking efforts.

Environmental exposures and mechanisms in allergy and asthma development.

Environmental exposures interplay with human host factors to promote the development and progression of allergic diseases. The worldwide prevalence of allergic disease is rising as a result of complex gene-environment interactions that shape the immune system and host response. Research shows an association between the rise of allergic diseases and increasingly modern Westernized lifestyles, which are characterized by increased urbanization, time spent indoors, and antibiotic usage. These environmental changes result in increased exposure to air and traffic pollution, fungi, infectious agents, tobacco smoke, and other early-life and lifelong risk factors for the development and exacerbation of asthma and allergic diseases. It is increasingly recognized that the timing, load, and route of allergen exposure affect allergic disease phenotypes and development. Still, our ability to prevent allergic diseases is hindered by gaps in understanding of the underlying mechanisms and interaction of environmental, viral, and allergen exposures with immune pathways that impact disease development. This Review highlights epidemiologic and mechanistic evidence linking environmental exposures to the development and exacerbation of allergic airway responses.

Addressing the Disease Burden of Vertically Acquired Hepatitis C Virus Infection Among Opioid-Exposed Infants.

BACKGROUND: This study aims to estimate the disease burden of vertically acquired hepatitis C virus (HCV) in a large Midwestern hospital and to identify factors associated with HCV diagnostic testing among high-risk infants. METHODS: This is a retrospective analysis of an infant cohort (n = 58 427) born from 2014 to 2016 in the Greater Cincinnati region, where universal maternal urine testing is conducted at delivery to assess for intrauterine drug exposure (IUDE). Demographics and birth characteristics were analyzed among high-risk infants to identify factors associated with receiving HCV testing. A nested, matched, case-control analysis examined the association of pediatric HCV infection and IUDE. RESULTS: The HCV prevalence rate among high-risk infants who received testing was 3.6%-5.2% of births. Approximately 66.7% of maternally acquired HCV infections may be missed using current testing recommendations. Prenatal care had no significant effect (adjusted odds ratio [aOR], 1.2; 95% confidence interval [CI], 0.4-3.5) on the odds of a high-risk infant receiving HCV testing. Opioid-exposed cases had a more than 6-fold increase in the odds of HCV infection (aOR, 6.2; 95% CI, 2.3-16.6]) compared with nonopioid exposed infants. CONCLUSIONS: The IUDE was significantly associated with increased odds of pediatric HCV infection in this population. The gaps in pediatric HCV testing identified in this study, despite known risk level and maternal infection, suggest the need for increased focus on HCV identification in the pediatric population.

The Enigma of Hepatitis E Virus.

Globally, hepatitis E virus (HEV) is the most common cause of acute viral hepatitis. HEV is endemic in many developing countries, yet it is far more common in industrialized, nonendemic countries than previously recognized. Nonetheless, HEV remains poorly characterized and is frequently unidentified or misdiagnosed by clinicians. Manifestation of disease, source of infection, and route of transmission vary by HEV genotype and epidemiology in endemic and nonendemic settings worldwide. HEV infection can be acute or chronic, further complicating the presentation, diagnosis, prognosis, and natural history of disease. However, accurate identification and diagnosis of HEV has important implications for patient management, disease control, prevention efforts, and characterization of mechanisms of transmission and epidemiology. Acute HEV infection is rarely diagnosed in industrialized, nonendemic countries; however, recent seroprevalence data collected using modern, highly sensitive testing assays demonstrate a surprisingly high prevalence of anti-HEV antibodies in these settings, suggesting common subclinical or unrecognized infection. These data suggest widespread underestimation of the global burden, population seroprevalence, and importance of HEV infection. Enhanced capacity for disease recognition, accurate diagnosis, and clinical awareness are critical to improving the management and reducing the burden of HEV infection worldwide.