Respiratory illness in families of preterm infants with chronic lung disease

Family history of asthma influences outpatient respiratory outcomes in children with BPD

INTRODUCTION

Preterm children with bronchopulmonary dysplasia (BPD) are at increased risk for intermittent and chronic respiratory symptoms during childhood and adult life. Identifying children at higher risk for respiratory morbidities in the outpatient setting could help improve long-term outcomes. In this study, we hypothesized that a family history of asthma (FHA) is a risk factor for higher acute care usage and respiratory symptoms in preterm infants/children with BPD, following initial discharge home.

METHODS

Subjects were recruited from the Johns Hopkins Bronchopulmonary Dysplasia outpatient clinic between January 2008 and February 2020 (n = 827). Surveys were administered to caregivers and demographics and clinical characteristics were obtained through chart review.

RESULTS

Demographic features associated with FHA included public health insurance, lower median household income, and nonwhite race. Children with FHA had higher odds of emergency department (ED) visits, systemic steroid use, nighttime respiratory symptoms, and activity limitations. There was no association between FHA and BPD severity.

CONCLUSION

This study found that children with BPD and FHA were more likely to have respiratory symptoms and acute care usage during the first 3 years of life and that FHA was associated with lower socioeconomic status. Although there was no association between FHA and BPD severity, FHA could predict an increased likelihood of both ED visits and need for systemic steroids in infants/children with BPD followed in the outpatient setting.

Respiratory symptoms and lung function in relation to atopy in children born preterm

Respiratory morbidity is a major health problem among children. The aim of this study was to compare the background of respiratory problems of children born preterm with that of children born full-term, with special reference to atopy. The study comprised two cohorts of 10-year-old children: a group of 72 children born preterm with birth weights of less than 1,501 g, and a group of 65 children born full-term with birth weights of over 2,500 g. Histories of respiratory and atopic symptoms, and of risk factors for atopy, were collected with a questionnaire. Predisposition to atopy was verified by skin-prick testing and by measuring serum total and antigen-specific IgEs. Lung function was evaluated by spirometry testing. Children born preterm had significantly more wheezing. In them, the lifetime prevalence of wheezing was 43%, vs. 17% in children born full-term (P = 0.001; odds ratio, 3.71; 95% confidence interval, 1.67-8.25). In the full-term group, wheezing was associated with atopy: 64% of wheezers were atopic; in the preterm group, 23% of wheezers were atopic (difference between groups, P = 0.024). Children born preterm expired significantly lower spirometry values of forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), FEV1/FVC ratio, forced expiratory flow after 50% of vital capacity has been exhaled (FEF50), and forced expiratory flow during middle half of FVC (FEF25-75). In the preterm group, wheezing, asthma, and low gestational age, but not atopy, were significantly associated with lower lung function values. Wheezers of the preterm group who still wheezed at age 10 were significantly more often atopic than those who no longer wheezed (62% vs. 9%, P = 0.006). In conclusion, we demonstrated a significant difference between groups in the association of atopy with respiratory problems. However, although atopy was not associated with a lifetime prevalence of respiratory symptoms in prematurely born children, an atopic predisposition in them was found to associate with persistence of wheezing.

Estimation of individual genetic effects from binary observations on relatives applied to a family history of respiratory illnesses and chronic lung disease of newborns

This paper considers methods for estimating the relationship between a binary response Y and the genetic effects responsible for a second binary trait Z. The responses Y are observed only for target individuals, and the responses Z are observed only for the relatives of these targets. The analysis consists of two parts. The first part concerns the analysis of the family data Z and the second part estimates the relation between the genetic effects and Y. For the family data, a generalized linear mixed model with a logit link and Gaussian genetic (random) effects is used. Estimates of the variances of the genetic effects are obtained by using a pseudo-profile log-likelihood method. Estimation of the log likelihood involves averaging over n-dimensional normal distributions, which is done by importance sampling. The methods used in the second part are straightforward. The methods are applied to a data set containing chronic lung disease (CLDN) responses of newborns and asthma (AS), allergy (AL), chronic bronchitis (CB) and eczema (EC) responses observed for the relatives of these newborns. The clinical question is whether genetic effects of AS, AL, CB, and EC have an effect on the risk for CLDN. It can be concluded that for AS, AL, CB, and EC, the influence of genetic effects is significant. However, these genetic predispositions have no significant effect on CLDN.

Mortality, severe respiratory distress syndrome, and chronic lung disease of the newborn are reduced more after prophylactic than after therapeutic administration of the surfactant Curosurf

OBJECTIVE

To test the hypothesis that prophylactic treatment with the surfactant Curosurf (Chiesi Farmaceutici SPA, Parma, Italy) improves survival and respiratory problems more than rescue treatment.

DESIGN

Meta-analysis of three prophylaxis versus rescue treatment trials, conducted in four countries.

METHODS

A meta-analysis was performed with the original, individual data of mortality, severe respiratory distress syndrome, and chronic lung disease of 671 newborns as outcomes. The random-effects logistic model (accounting for the trial-within-country structure) was applied and adjusted for imbalances in covariates.

RESULTS

The probability of each outcome differed between the countries, but the actual treatment effect itself did not. The adjusted odds ratios (ORs) and confidence intervals (CIs) for prophylaxis versus rescue were as follows: mortality: OR, .47; 95% CI, .30 to .73; severe RDS: OR, .50; 95% CI, .33 to .74; and chronic lung disease of the newborn in the survivors at day 28 after birth: OR, .54; 95% CI, .34 to .86. Gender, birth weight, gestational age, and prenatal administration of glucocorticosteroids were significant confounding covariates.

CONCLUSION

The analysis shows that for the porcine surfactant Curosurf, prophylactic administration of surfactant has significant advantages over rescue therapy.

Eosinophil cationic protein in tracheal aspirates of preterm infants with bronchopulmonary dysplasia

Eosinophil cationic protein was elevated during the first week of life in tracheal aspirates from 11 preterm infants in whom bronchopulmonary dysplasia subsequently developed compared with 8 preterm and 8 term infants without bronchopulmonary dysplasia. Eosinophil cationic protein levels increased progressively with continued intubation in the infants with bronchopulmonary dysplasia but remained low in a comparison group of term infants. We suggest that eosinophils participate in the inflammatory process in bronchopulmonary dysplasia and may contribute to lung injury.