Differences in autophagy marker levels at birth in preterm vs. term infants.

BACKGROUND: Preterm infants are susceptible to oxidative stress and prone to respiratory diseases. Autophagy is an important defense mechanism against oxidative-stress-induced cell damage and involved in lung development and respiratory morbidity. We hypothesized that autophagy marker levels differ between preterm and term infants. METHODS: In the prospective Basel-Bern Infant Lung Development (BILD) birth cohort we compared cord blood levels of macroautophagy (Beclin-1, LC3B), selective autophagy (p62) and regulation of autophagy (SIRT1) in 64 preterm and 453 term infants. RESULTS: Beclin-1 and LC3B did not differ between preterm and term infants. However, p62 was higher (0.37, 95% confidence interval (CI) 0.05;0.69 in log2-transformed level, p = 0.025, padj = 0.050) and SIRT1 lower in preterm infants (-0.55, 95% CI -0.78;-0.31 in log2-transformed level, padj < 0.001). Furthermore, p62 decreased (padj-value for smoothing function was 0.018) and SIRT1 increased (0.10, 95% CI 0.07;0.13 in log2-transformed level, padj < 0.001) with increasing gestational age. CONCLUSION: Our findings suggest differential levels of key autophagy markers between preterm and term infants. This adds to the knowledge of the sparsely studied field of autophagy mechanisms in preterm infants and might be linked to impaired oxidative stress response, preterm birth, impaired lung development and higher susceptibility to respiratory morbidity in preterm infants. IMPACT: To the best of our knowledge, this is the first study to investigate autophagy marker levels between human preterm and term infants in a large population-based sample in cord blood plasma This study demonstrates differential levels of key autophagy markers in preterm compared to term infants and an association with gestational age This may be linked to impaired oxidative stress response or developmental aspects and provide bases for future studies investigating the association with respiratory morbidity.

Borrelia burgdorferi infections in children and adolescents in Switzerland - a seroprevalence study 2023/2024 (BOBUINCA).

BACKGROUND: Lyme borreliosis is one of the most prevalent tick-borne diseases in Europe. Studies on seroprevalence of Borrelia burgdorferi IgG antibodies in children are rare. The aim of this study was to determine the seroprevalence of B. burgdorferi IgG antibodies in children and adolescents residing in North-Western Switzerland and neighbouring countries. METHODS: Prospective cross-sectional observational single-centre study using left-over plasma of asymptomatic paediatric patients. Included were children aged 1-17 years living in North-Western Switzerland and bordering areas of France and Germany. Excluded were children with symptoms of Lyme borreliosis or a chronic disease possibly affecting plasma antibodies (immunodeficiency syndrome, systemic lupus erythematosus) or with such medication (e.g., intravenous immunoglobuline treatment, allogenic stem cell transplantation, immunosuppressive treatment) as well as refugees seeking asylum. IgG antibodies against B. burgdorferi were measured by ELISA and positive or borderline results by line blot. Positivity was defined as scenario 1: ELISA positive/line blot positive or borderline OR ELISA borderline/line blot positive. Scenario 2: ELISA positive or borderline/line blot positive. A multivariable logistic regression model for seropositivity was applied. RESULTS: 962 children were included (mean age 9.63 years, standard deviation 5.01, 54.5% males). Seroprevalence for scenario 1 was 13.3% (95% CI: 11.2-15.6) and for scenario 2 11.2% (95% CI: 9.3-13.4). Seroprevalence (scenario 1) was comparable for age groups, sex and rural versus urban residence. CONCLUSION: This study shows an increased seroprevalence for B. burgdorferi in the paediatric age compared to previous childhood studies. We also found an increased risk for B. burgdorferi infection at young age.

Antibiotics in pregnancy influence nasal microbiome and respiratory morbidity in infancy.

Background: The effects of prenatal antibiotic exposure on respiratory morbidity in infancy and the involved mechanisms are still poorly understood. We aimed to examine whether prenatal antibiotic exposure in the third trimester is associated with nasal microbiome and respiratory morbidity in infancy and at school age, and whether this association with respiratory morbidity is mediated by the nasal microbiome. Methods: We performed 16S ribosomal RNA gene sequencing (regions V3-V4) on nasal swabs obtained from 296 healthy term infants from the prospective Basel-Bern birth cohort (BILD) at age 4-6 weeks. Information about antibiotic exposure was derived from birth records and standardised interviews. Respiratory symptoms were assessed by weekly telephone interviews in the first year of life and a clinical visit at age 6 years. Structural equation modelling was used to test direct and indirect associations accounting for known risk factors. Results: α-Diversity indices were lower in infants with antibiotic exposure compared to nonexposed infants (e.g. Shannon index p-value 0.006). Prenatal antibiotic exposure was also associated with a higher risk of any, as well as severe, respiratory symptoms in the first year of life (risk ratio 1.38, 95% CI 1.03-1.84; adjusted p-value (padj)=0.032 and risk ratio 1.75, 95% CI 1.02-2.97; padj=0.041, respectively), but not with wheeze or atopy in childhood. However, we found no indirect mediating effect of nasal microbiome explaining these clinical symptoms. Conclusion: Prenatal antibiotic exposure was associated with lower diversity of nasal microbiome in infancy and, independently of microbiome, with respiratory morbidity in infancy, but not with symptoms later in life.