Infant RSV immunoprophylaxis changes nasal epithelial DNA methylation at 6 years of age

BackgroundRespiratory syncytial virus (RSV) infection has been associated with childhood wheeze and asthma, and potential mechanisms include persistent epigenetic effects.MethodsIn the randomized, placebo-controlled MAKI trial, 429 preterm infants randomly received RSV immunoprophylaxis with palivizumab or placebo during their first RSV season. Children were followed until age 6 for asthma evaluation. DNA methylation in cells obtained by nasal brushes at age 6 was measured by Illumina MethylationEPIC array.ResultsRSV immunoprophylaxis in infancy had a significant impact on global methylation patterns in nasal cells at age 6. The first principal component (PC) related to the immunoprophylaxis intervention was enriched for the pathway "detection of chemical stimulus involved in sensory perception of smell" and "T cell differentiation." Subsequent analysis of these PCs indicated an effect of RSV immunoprophylaxis on cell type composition of nasal brushed cells. Three CpG sites, cg18040241, cg08243963, and cg19555973 which are annotated to genes GLB1L2, SC5D, and BPIFB1, were differentially methylated at genome-wide significance, but were not associated with asthma. ConclusionThe study provides the first proof of concept that RSV immunoprophylaxis during infancy has long-term effects on nasal epigenetic signatures at age 6, relating to host sensory perception, epidermal growth factor receptor signaling, and adaptive immune responses.</p

Prediction model of RSV-hospitalization in late preterm infants : An update and validation study

BACKGROUND: New vaccines and RSV therapeutics have been developed in the past decade. With approval of these new pharmaceuticals on the horizon, new challenges lie ahead in selecting the appropriate target population. We aimed to improve a previously published prediction model for prediction of RSV-hospitalization within the first year of life. METHODS: Two consecutive prospective multicenter birth cohort studies were performed from June 2008 until February 2015. The first cohort (RISK-I, n=2524, 2008-2011) was used to update the existing model. The updated model was subsequently validated in the RISK-II cohort (n=1564, 2011-2015). We used the TRIPOD criteria for transparent reporting. RESULTS: 181 infants (n=127 in RISK-I, n=54 in RISK-II) were hospitalized for RSV within their first year of life. The updated model included the following predictors; day care attendance and/or siblings (OR: 5.3; 95% CI 2.8-10.1), birth between Aug. 14th and Dec. 1st (OR: 2.4; 1.8-3.2), neonatal respiratory support (OR 2.2; 1.6-3.0), breastfeeding ≤4months (OR 1.6; 1.2-2.2) and maternal atopic constitution (OR 1.5; 1.1-2.1). The updated models' discrimination was superior to the original model in the RISK-II cohort (AUROC 0.72 95% CI 0.65-0.78 versus AUROC 0.66, 95% CI 0.60-0.73, respectively). The updated model was translated into a simple nomogram to be able to distinguish infants with high versus low risk of RSV-hospitalization. CONCLUSION: We developed and validated a clinical prediction model to be able to predict RSV-hospitalization in preterm infants born within 32-35weeks gestational age. A simple nomogram was developed to target RSV therapeutics to those children who will benefit the most

Distribution of Baseline Patient Characteristics in the Derivation and Validation Cohort (Number(percentage)).

*<p>No infants developed BPD ** either exclusive breastfeeding or mixed with formula feeding # predicted by parents at birth.</p

Results of the multivariable logistic regression analyses in the derivation cohort (n = 1227) and the performance of the model in the validation cohort (n = 1194): predictors for RSV hospitalization after bootstrapping.

*<p>either exclusive breastfeeding or mixed with formula feeding # predicted by parents at birth.</p

Distribution of potential predictors across cases and non-cases in the derivation and validation cohort.

*<p>either exclusive breastfeeding or mixed with formula feeding # predicted by parents at birth.</p

Cost-effectiveness of rule-based immunoprophylaxis against respiratory syncytial virus infections in preterm infants

The objective of the paper is to assess the cost-effectiveness of targeted respiratory syncytial virus (RSV) prophylaxis based on a validated prediction rule with 1-year time horizon in moderately preterm infants compared to no prophylaxis. Data on health care consumption were derived from a randomised clinical trial on wheeze reduction following RSV prophylaxis and a large birth cohort study on risk prediction of RSV hospitalisation. We calculated the incremental cost-effectiveness ratio (ICER) of targeted RSV prophylaxis vs. no prophylaxis per quality-adjusted life year (QALYs) using a societal perspective, including medical and parental costs and effects. Costs and health outcomes were modelled in a decision tree analysis with sensitivity analyses. Targeted RSV prophylaxis in infants with a first-year RSV hospitalisation risk of > 10% resulted in a QALY gain of 0.02 (0.931 vs. 0.929) per patient against additional cost of €472 compared to no prophylaxis (ICER €214,748/QALY). The ICER falls below a threshold of €80,000 per QALY when RSV prophylaxis cost would be lowered from €928 (baseline) to €406 per unit. At a unit cost of €97, RSV prophylaxis would be cost saving. Conclusions: Targeted RSV prophylaxis is not cost-effective in reducing RSV burden of disease in moderately preterm infants, but it can become cost-effective if lower priced biosimilar palivizumab or a vaccine would be available

Operating Characteristics for Each Threshold of the RISK model in the validation cohort (n = 1194).

<p>Operating Characteristics for Each Threshold of the RISK model in the validation cohort (n = 1194).</p

Patient flowchart derivation and validation cohort.

<p>Patient flowchart derivation and validation cohort.</p

RSV hospitalization in infancy increases the risk of current wheeze at age 6 in late preterm born children without atopic predisposition

Severe respiratory syncytial virus (RSV) infection during infancy is associated with ongoing respiratory morbidity. In a large birth cohort of 2210 healthy preterm infants born at 32-35 weeks of gestation, we aimed to determine the role of atopy in the link between RSV hospitalization and current wheeze at age 6. We defined current wheeze as parent-reported wheeze or the use of respiratory medication in the past 12 months. Based on a positive family history of atopic disease, we distinguished between children with and without atopic predisposition. Six-year follow-up data was obtained in 997/1559 (64%) children of which 102 (10.2%) children had been hospitalized with RSV during infancy. Current wheeze was present in 184/997 (18.6%) children. RSV hospitalization was an independent risk factor for current wheeze in children without atopic predisposition (aOR 4.05 [95% CI 1.22-12.52]) but not in children with this atopic background (aOR 1.50 [95% CI 0.81-2.71]).Conclusion: This is the largest published birth cohort demonstrating that in late preterm infants, atopic predisposition defines the relationship between RSV hospitalization and current wheeze. Future RSV prevention trials aiming to prevent ongoing respiratory symptoms should be analyzed separately for atopic status. What is Known: • RSV infection is responsible for a significant burden of disease in young children worldwide. • Severe RSV infection in early life is associated with asthmatic symptoms later in life. What is New: • This is the largest published birth cohort reporting about the role of atopic predisposition in the link between severe RSV infection and current wheeze at school age. • We show that RSV hospitalization in infancy is an independent risk factor for current wheeze in late preterm children without atopic predisposition at age 6. This was not seen in children with atopic predisposition

Population-Attributable Risk of Risk Factors for Recurrent Wheezing in Moderate Preterm Infants During the First Year of Life

BACKGROUND: Recurrent wheezing in young infants has a high prevalence, influences quality of life, and generates substantial health care costs. We previously showed that respiratory syncytial virus infection is an important mechanism of recurrent wheezing in moderate preterm infants. We aimed to provide population-attributable risks (PAR) of risk factors for recurrent wheezing during the first year of life in otherwise healthy moderate preterm infants. METHODS: RISK is a multicentre prospective birth cohort study of 4424 moderate preterm infants born at 32-35 weeks gestation. We estimated PAR of risk factors for recurrent wheezing, which was defined as three or more parent-reported wheezing episodes during the first year of life. RESULTS: We evaluated 3952 (89%) children at 1 year of age, of whom 705 infants (18%) developed recurrent wheezing. Fourteen variables were independently associated with recurrent wheezing. Hospitalisation for respiratory syncytial virus bronchiolitis had a strong relationship with recurrent wheezing (RR 2.6; 95% confidence interval, CI, 2.2, 3.1), but a relative modest PAR (8%; 95% CI 6, 11%) which can be explained by a low prevalence (13%). Day-care attendance showed a strong relationship with recurrent wheezing (RR 1.9; 95% CI 1.7, 2.2) and the highest PAR (32%; 95% CI 23, 37%) due to a high prevalence (67%). The combined adjusted PAR for the 14 risk factors associated with recurrent wheezing was 49% (95% CI 46, 52%). CONCLUSIONS: In moderate preterm infants, day-care attendance has the largest PAR for recurrent wheezing. Trial evidence is needed to determine the potential benefit of delayed day-care attendance in this population