Lung Function of Preterm Children Parsed by a Polygenic Risk Score for Adult COPD

Sex-specific spirometry effects of adult COPD polygenic score in children with asthma

Chronic obstructive pulmonary disease (COPD) is a leading cause of death and disability globally. While genetic and environmental risk factors are known, these insights have not yet resulted in individualized prevention strategies. Polygenic scores (PS) have enhanced our understanding of genetic risk and early-life lung function differences, but their applicability across diverse populations remains unclear. As such, we aimed evaluate whether a COPD PS captures population-wide risk or disproportionately affects sub-populations defined by ancestry or sex. This observational study assessed the association between a previously validated COPD PS and lung function in children with asthma, using spirometry results from children with asthma in the Center of Applied Genomics biorepository. Mixed-effects linear regression models were used to examine the relationship between PS and spirometry measures (FEV1 and FEV1/FVC), with stratified analyses by sex and ancestry. 25,477 spirometry results from 6336 patients were included. Population-wide, children in the high PS group had significantly lower FEV1/FVC z-scores compared to the low PS group (P = 0.0037, beta =  - 0.11, 95% confidence interval [CI] - 0.18 to - 0.036). When stratified by sex, high PS was associated with lower FEV1/FVC z-scores in males (P = 0.0088, beta =  - 0.14, 95% CI - 0.24 to - 0.035), but no significant effect was found in females. Ancestry-specific analysis revealed that males of European (EUR) ancestry with high PS had significantly lower FEV1 (P = 0.0035, beta =  - 0.37, 95% CI - 0.63 to - 0.12) and FEV1/FVC z-scores (P = 0.00076, beta =  - 0.35, 95% CI - 0.55 to - 0.15). No significant associations were observed in females with EUR ancestry or in African ancestry groups. Logistic regression analysis showed that high PS in males of EUR ancestry increased the odds of having an FEV1/FVC ratio below 0.7, a marker for COPD (P = 0.0074, OR = 2.01, 95% CI 1.19 to 3.31). This study demonstrates sex-specific effects of a COPD PS in pediatric asthma patients, with males of EUR ancestry at highest risk. The findings underscore the need to include diverse populations in genomic studies to improve the generalizability of PS for COPD prevention.

Epigenetic training of human bronchial epithelium cells by repeated rhinovirus infections

BACKGROUND

Humans are subjected to various environmental stressors (bacteria, viruses, pollution) throughout life. As such, an inherent relationship exists between the effect of these exposures with age. The impact of these environmental stressors can manifest through DNA methylation (DNAm). However, whether these epigenetic effects selectively target genes, pathways, and biological regulatory mechanisms remains unclear. Due to the frequency of human rhinovirus (HRV) infections throughout life (particularly in early development), we propose the use of HRV under controlled conditions can model the effect of multiple exposures to environmental stressors.

METHODS

We generated a prediction model by combining transcriptome and DNAm datasets from human epithelial cells after repeated HRV infections. We applied a novel experimental statistical design and method to systematically explore the multifaceted experimental space (number of infections, multiplicity of infections and duration). Our model included 35 samples, each characterized by the three parameters defining their infection status.

RESULTS

Trainable genes were defined by a consistent linear directionality in DNAm and gene expression changes with successive infections. We identified 77 trainable genes which could be further explored in future studies. The identified methylation sites were tracked within a pediatric cohort to determine the relative changes in candidate-trained sites with disease status and age.

CONCLUSIONS

Repeated viral infections induce an immune training response in bronchial epithelial cells. Training-sensitive DNAm sites indicate alternate divergent associations in asthma compared to healthy individuals. Our novel model presents a robust tool for identifying trainable genes, providing a foundation for future studies.

Less Invasive Surfactant Administration for Preterm Infants - State of the Art

BACKGROUND

Less invasive surfactant administration (LISA) has become the preferred method of surfactant administration for spontaneously breathing babies on continuous positive airway pressure (CPAP).

SUMMARY

The development of LISA followed the need to combine CPAP and surfactant replacement as mainstay treatment options for respiratory distress syndrome, thereby avoided exposure to positive pressure ventilation.

KEY MESSAGES

This review summarises the current knowns and unknowns of LISA including the physiological concept, its relevance for short-term and long-term outcomes and the challenges for practical implementation of LISA as part of a less invasive respiratory care bundle. Further, we provide an update of the evidence on alternatives to LISA, for example, nebulised surfactant administration, pharyngeal deposition of surfactant and delivery via supraglottic airway.

Exploring the genetics of airflow limitation in lung function across the lifespan - a polygenic risk score study

Background

Chronic obstructive pulmonary disease (COPD) is caused by interactions between many factors across the life course, including genetics. A proportion of COPD may be due to reduced lung growth in childhood. We hypothesized that a polygenic risk score (PRS) for COPD is associated with lower lung function already in childhood and up to adulthood.

Methods

A weighted PRS was calculated based on the 82 association signals (p ≤ 5 × 10-8) revealed by the largest GWAS of airflow limitation (defined as COPD) to date. This PRS was tested in association with lung function measures (FEV1, FVC, and FEV1/FVC) in subjects aged 4-50 years from 16 independent cohorts participating in the Chronic Airway Diseases Early Stratification (CADSET) Clinical Research Collaboration. Age-stratified meta-analyses were conducted combining the results from each cohort (n = 45,406). These findings were validated in subjects >50 years old.

Findings

We found significant associations between the PRS for airflow limitation and: (1) lower pre-bronchodilator FEV1/FVC from school age (7-10 years; β: -0.13 z-scores per one PRS z-score increase [-0.15, -0.11], q-value = 7.04 × 10-53) to adulthood (41-50 years; β: -0.16 [-0.19, -0.13], q-value = 1.31 × 10-24); and (2) lower FEV1 (from school age: 7-10 years; β: -0.07 [-0.09, -0.05], q-value = 1.65 × 10-9, to adulthood: 41-50 years; β: -0.17 [-0.20, -0.13], q-value = 4.48 x 10-20). No effect modification by smoking, sex, or a diagnosis of asthma was observed.

Interpretation

We provide evidence that a higher genetic risk for COPD is linked to lower lung function from childhood onwards.

Funding

This study was supported by CADSET, a Clinical Research Collaboration of the European Respiratory Society.

Pathophysiology and genomics of bronchiectasis

Bronchiectasis is a complex and heterogeneous inflammatory chronic respiratory disease with an unknown cause in around 30-40% of patients. The presence of airway infection together with chronic inflammation, airway mucociliary dysfunction and lung damage are key components of the vicious vortex model that better describes its pathophysiology. Although bronchiectasis research has significantly increased over the past years and different endotypes have been identified, there are still major gaps in the understanding of the pathophysiology. Genomic approaches may help to identify new endotypes, as has been shown in other chronic airway diseases, such as COPD.Different studies have started to work in this direction, and significant contributions to the understanding of the microbiome and proteome diversity have been made in bronchiectasis in recent years. However, the systematic application of omics approaches to identify new molecular insights into the pathophysiology of bronchiectasis (endotypes) is still limited compared with other respiratory diseases.Given the complexity and diversity of these technologies, this review describes the key components of the pathophysiology of bronchiectasis and how genomics can be applied to increase our knowledge, including the study of new techniques such as proteomics, metabolomics and epigenomics. Furthermore, we propose that the novel concept of trained innate immunity, which is driven by microbiome exposures leading to epigenetic modifications, can complement our current understanding of the vicious vortex. Finally, we discuss the challenges, opportunities and implications of genomics application in clinical practice for better patient stratification into new therapies.

ERS International Congress 2023: highlights from the Basic and Translational Sciences Assembly

Early career members of Assembly 3 (Basic and Translational Sciences) of the European Respiratory Society (ERS) summarise the key messages discussed during six selected sessions that took place at the ERS International Congress 2023 in Milan, Italy. Aligned with the theme of the congress, the first session covered is "Micro- and macro-environments and respiratory health", which is followed by a summary of the "Scientific year in review" session. Next, recent advances in experimental methodologies and new technologies are discussed from the "Tissue modelling and remodelling" session and a summary provided of the translational science session, "What did you always want to know about omics analyses for clinical practice?", which was organised as part of the ERS Translational Science initiative's aims. The "Lost in translation: new insights into cell-to-cell crosstalk in lung disease" session highlighted how next-generation sequencing can be integrated with laboratory methods, and a final summary of studies is presented from the "From the transcriptome landscape to innovative preclinical models in lung diseases" session, which links the transcriptome landscape with innovative preclinical models. The wide range of topics covered in the selected sessions and the high quality of the research discussed demonstrate the strength of the basic and translational science being presented at the international respiratory conference organised by the ERS.

ERS International Congress 2023: highlights from the Paediatrics Assembly

Respiratory health in children is essential for general wellbeing and healthy development in the short and long term. It is well known that many respiratory diseases in adulthood have their origins in early life, and therefore research on prevention of respiratory diseases and management of children with respiratory diseases will benefit patients during the full life course. Scientific and clinical advances in the field of respiratory health are moving at a fast pace. This article summarises some of the highlights in paediatric respiratory medicine presented at the hybrid European Respiratory Society (ERS) International Congress 2023 which took place in Milan (Italy). Selected sessions are summarised by Early Career Members of the Paediatrics Assembly (Assembly 7) under the supervision of senior ERS officers, and cover a wide range of research areas in children, including respiratory physiology and sleep, asthma and allergy, cystic fibrosis, respiratory infection and immunology, neonatology and intensive care, respiratory epidemiology and bronchology.

Increasing airway obstruction through life following bronchopulmonary dysplasia: a meta-analysis

Background

Few studies exist investigating lung function trajectories of those born preterm; however growing evidence suggests some individuals experience increasing airway obstruction throughout life. Here we use the studies identified in a recent systematic review to provide the first meta-analysis investigating the impact of preterm birth on airway obstruction measured by the forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) ratio.

Methods

Cohorts were included for analysis if they reported FEV1/FVC in survivors of preterm birth (<37 weeks' gestation) and control populations born at term. Meta-analysis was performed using a random effect model, expressed as standardised mean difference (SMD). Meta-regression was conducted using age and birth year as moderators.

Results

55 cohorts were eligible, 35 of which defined groups with bronchopulmonary dysplasia (BPD). Compared to control populations born at term, lower values of FEV1/FVC were seen in all individuals born preterm (SMD -0.56), with greater differences seen in those with BPD (SMD -0.87) than those without BPD (SMD -0.45). Meta-regression identified age as a significant predictor of FEV1/FVC in those with BPD with the FEV1/FVC ratio moving -0.04 sds away from the term control population for every year of increased age.

Conclusions

Survivors of preterm birth have significantly increased airway obstruction compared to those born at term with larger differences in those with BPD. Increased age is associated with a decline in FEV1/FVC values suggesting increased airway obstruction over the life course.

Genes, Environment, and Loss of Lung Function in Premature Infants

In the fourth verse of the 1978 best-selling song entitled "The Gambler," Kenny Rogers sings, "Every gambler knows that … every hand's a winner and every hand's a loser…." To some extent this gambler's knowledge is a close analogy to the play of chance that all of us experience at the moment of meiosis when "crossing over" occurs and we are given our somatic chromosomal makeup. At that point, Mother Nature has dealt us our hand; from that moment forward, it is environmental exposures that shape our destiny.