Project description:BackgroundUreaplasma urealyticum and U. parvum have been associated with respiratory diseases in premature newborns, but their role in the pathogenesis of the respiratory distress syndrome (RDS) is unclear. The aim of this study was to detect, using molecular techniques, the role of Mycoplasma spp. and Ureaplasma spp. in respiratory secretion and blood specimens of preterm newborns with or without RDS and to evaluate the prevalence of perinatal U. urealyticum or U. parvum infection. The influence of chemotherapy on the clinical course was also evaluated.MethodsTracheal aspirate or nasopharingeal fluid samples from 50 preterm babies with (24) or without RDS (26) were analysed for detection of U. urealyticum and U. parvum by culture identification assay and PCR. Sequencing analysis of amplicons allowed us to verify the specificity of methods. Clarithromycin (10 mg kg-1 twice a day) was administered in ureaplasma-positive patients who presented clinical signs of RDS.Results15/24 neonates with RDS (p < 0.001) and 4/26 without RDS were found PCR-positive for U. urealyticum or U. parvum. Culture identification assay was positive in 5/50 newborns, three of which with RDS. Sequencing analyses confirmed the specificity of these methods. Association of patent ductus arteriosus with ureaplasma colonization was more statistically significant (p = 0.0004) in patients with RDS than in those without RDS.ConclusionColonization of the lower respiratory tract by Ureaplasma spp. and particularly by U. parvum in preterm newborns was related to RDS. The routine use of molecular methods could be useful to screen candidate babies for etiologic therapy.
Project description:Ureaplasma spp. respiratory tract colonization is a significant risk factor for bronchopulmonary dysplasia (BPD), a chronic lung disorder in preterm infants. As an initial step preparatory to future clinical trials to evaluate the clinical efficacy of azithromycin to prevent BPD, the authors characterized the pharmacokinetics, safety, and biological effects of a single intravenous dose of azithromycin (10 mg/kg) in preterm neonates (n = 12) 24 to 28 weeks gestation at risk for Ureaplasma infection and BPD. A 2-compartment structural model with the clearance and volume of peripheral compartment (V2) allometrically scaled on body weight (WT) best described the pharmacokinetics of azithromycin in preterm neonates. The estimated parameters were clearance [0.18 L/h × WT(kg)(0.75)], intercompartmental clearance [1.0 L/h], volume of distribution of central compartment [0.93 L], and V2 [14.2 L × WT(kg)]. There were no serious adverse events attributed to azithromycin. A single dose of azithromycin did not suppress inflammatory cytokines or myeloperoxidase activity in tracheal aspirates. These results demonstrated the safety of azithromycin and developed a pharmacokinetic model that is useful for future simulation-based clinical trials for eradicating Ureaplasma and preventing BPD in preterm neonates.
Project description:Anemia is commonly seen in preterm infants. It may reduce the capacity of hemoglobin to transport oxygen throughout the body and may result in tissue and organ dysfunction. This study aimed to investigate the effect of anemia on the development of bronchopulmonary dysplasia (BPD) in preterm infants. 243 infants who were admitted to BaYi Children's Hospital Affiliated to Clinical Medical College in Beijing Military General Hospital with gestational age (GA) less than 32 weeks from February, 2014 to February, 2015 were included in the study. Maternal and infant data were recorded. Multivarariate logistic regression analysis was performed to determine the association between anemia and BPD. Of 243 preterm infants, the incidence of anemia was higher in BPD patients than non-BPD patients (p < 0.001). Mean Hct in BPD patients was lower than non-BPD patients at different time points in 1d, 7d, 14d, and 21d. Controlling for other confounding factors, early anemia was associated with an increased risk of BPD. Number of transfusions is also a significant risk factor for BPD (p = 0.001). Therefore, prevention and treatment of early anemia is necessary and reducing number of transfusions may reduce the incidence of BPD in preterm infants.
Project description:ImportanceBronchopulmonary dysplasia (BPD), a chronic lung disease of prematurity, remains one of the major and most common complications of very preterm birth. Insight into factors associated with the pathogenesis of BPD is key to improving its prevention and treatment.ObjectiveTo perform a systematic review, meta-analysis, and metaregression of clinical studies exploring the association between chorioamnionitis (CA) and BPD in preterm infants.Data sourcesPubMed and Embase were searched without language restriction (last search, October 1, 2018). Key search terms included bronchopulmonary dysplasia, chorioamnionitis, and risk factors.Study selectionIncluded studies were peer-reviewed studies examining preterm (<37 weeks' gestation) or very low-birth-weight (<1500 g) infants and reporting primary data that could be used to measure the association between exposure to CA and the development of BPD.Data extraction and synthesisThe Meta-analysis of Observational Studies in Epidemiology (MOOSE) guideline was followed. Data were independently extracted by 2 researchers. A random-effects model was used to calculate odds ratios (ORs) and 95% CIs. Heterogeneity in effect size across studies was studied using multivariate, random-effects metaregression analysis.Main outcomes and measuresThe primary outcome was BPD, defined as supplemental oxygen requirement on postnatal day 28 (BPD28) or at the postmenstrual age of 36 weeks (BPD36). Covariates considered as potential confounders included differences between CA-exposed and CA-unexposed infants in gestational age, rates of respiratory distress syndrome (RDS), exposure to antenatal corticosteroids, and rates of early- and late-onset sepsis.ResultsA total of 3170 potentially relevant studies were found, of which 158 met the inclusion criteria (244 096 preterm infants, 20 971 CA cases, and 24 335 BPD cases). Meta-analysis showed that CA exposure was significantly associated with BPD28 (65 studies; OR, 2.32; 95% CI, 1.88-2.86; P < .001; heterogeneity: I2 = 84%; P < .001) and BPD36 (108 studies; OR, 1.29; 95% CI, 1.17-1.42; P < .001; heterogeneity: I2 = 63%; P < .001). The association between CA and BPD remained significant for both clinical and histologic CA. In addition, significant differences were found between CA-exposed and CA-unexposed infants in gestational age, birth weight, odds of being small for gestational age, exposure to antenatal corticosteroids, and early- and late-onset sepsis. Chorioamnionitis was not significantly associated with RDS (48 studies; OR, 1.10; 95% CI, 0.92-1.34; P = .24; heterogeneity: I2 = 90%; P < .001), but multivariate metaregression analysis with backward elimination revealed that a model combining the difference in gestational age and the odds of RDS was associated with 64% of the variance in the association between CA and BPD36 across studies.Conclusions and relevanceThe results of this study confirm that among preterm infants, exposure to CA is associated with a higher risk of developing BPD, but this association may be modulated by gestational age and risk of RDS.
Project description:ObjectiveUreaplasma respiratory tract colonization is associated with bronchopulmonary dysplasia (BPD) in preterm infants. Whether the 4 Ureaplasma parvum and 10 Ureaplasma urealyticum serovars differ in virulence is unknown. This study was conducted to determine the distribution of Ureaplasma serovars in respiratory secretions of a prospective cohort of preterm infants and to assess whether any of the serovars are associated with BPD.MethodsSerial endotracheal and/or nasopharyngeal aspirates were obtained for Ureaplasma culture and PCR from 136 infants of gestational age <33 weeks. All positive samples were speciated and serovars were determined by real-time PCR.ResultsA total of 51 (37.5%) infants were Ureaplasma-positive one or more times during the first month of life. Respiratory colonization was inversely related to gestational age. Sixty-five percent of infants <26 weeks compared with 31% infants ≥ 26 weeks were culture or PCR positive. U. parvum was more common (N = 32, 63%) than U. urealyticum (N = 17, 33%); both species were present in 2 samples. Serovars 3 and 6 alone and in combination accounted for 96% U. parvum isolates. U. urealyticum isolates were commonly a mixture of multiple serovars, with serovar 11 alone or combined with other serovars (10/17, 59%) being the most common serovar. No individual species or serovars or serovar mixtures were associated with moderate-to-severe BPD.ConclusionsU. parvum serovars 3 and 6 and U. urealyticum serovar 11 were the most common serovars detected in respiratory samples from a prospective cohort of preterm infants.
Project description:Anemia and the need for transfusion of packed red blood cells (PRBCs) are common in preterm infants. PRBC transfusion increases the oxygen carrying capacity of hemoglobin and may result in higher rates of organ dysfunction. To determine whether PRBC transfusion in preterm infants is associated with an increased incidence of bronchopulmonary dysplasia (BPD), this retrospective study was performed on neonates with birth weights ≤ 1,500 g or gestational age ≤ 32 weeks admitted from August, 2008 to November, 2013. Infants who received PRBC transfusion before the diagnosis of BPD and those who did not receive PRBC transfusion or received PRBC transfusion after diagnosis of BPD were compared for incidence of BPD and other morbidities. Of 231 preterm infants, 137 received PRBC transfusion before BPD was diagnosed (group 1) and 94 did not (group 2). The incidence of BPD was significantly higher in group 1 than in group 2 (37.2% vs. 2.1%, P < 0.00001). After adjusting for potential risk factors, the adjusted odds ratio for BPD was 9.80 (95% confidence interval, 1.70-56.36; P = 0.01). This study demonstrated an association between PRBC transfusion and BPD in preterm infants. A cautious approach to PRBC transfusion in these infants is warranted.
Project description:Bronchopulmonary dysplasia (BPD) is a lung disease in premature infants characterized by impaired pulmonary development which persists into later life. While advances in neonatal care have improved survival rates of premature infants, cases of BPD haves been increased. Therapeutic options are limited for prevention and treatment. This study was designed to explore the relationship between gestational age (GA), birth weight and estímate blood cell-type composition in premature infants and to elucidate early epigenetic biomarkers associated with BPD. Peripheral blood DNA (at days 14 and 28) from preterm neonates that went on to develop BPD (n = 14) or not (nonBPD, n = 93) was applied to Illumina EPIC methylation arrays. Using DNA methylation analysis of cord blood DNA, we investigated association of GA and birth weight with the estimated distribution of cord blood cell types, particularly the nucleated red blood cell (NRBC) in a pilot-size cohort of preterm infants with or without BPD. We describe changes in methylation-based estimates of blood cell-type composition in relation to GA and birth weight. After adjusting for covariates (GA, birth weight, cell type proportions, etc.) we identify differentially methylated CpGs and genes associated with BPD at different time points.
Project description:BackgroundIt is unclear whether Ureaplasma-associated pneumonia and azithromycin treatment affect the risk for bronchopulmonary dysplasia (BPD).MethodsA retrospective cohort study was performed in very low birth weight (VLBW) infants who tested positive for Ureaplasma within 72 h after birth in a tertiary unit. Chest X-ray (CXR) and laboratory test were performed before and after azithromycin treatment. Multivariate logistic regression analysis was used to identify the independent association between BPD and Ureaplasma-associated pneumonia, as well as BPD and effective azithromycin treatment.ResultsA total of 118 infants were included in the current study, of whom 36 developed BPD (defined as supplemental oxygen needed at postmenstrual age 36 weeks or discharge). The rate of BPD was significantly higher in infants with Ureaplasma-associated pneumonia (44.6%) compared to infants with Ureaplasma colonization (17.7%, P = 0.002). After adjusting for confounders, an effective azithromycin treatment was significantly associated with reduced risk of BPD [odd ratio (OR) 0.011; 95% confidence interval (CI): 0.000-0.250), whereas Ureaplasma-associated pneumonia was not significantly associated with BPD (OR 1.835; 95% CI: 0.548-6.147).ConclusionEffective Azithromycin treatment in Ureaplasma positive VLBW infants was associated with a reduced risk of BPD.
Project description:BackgroundThis study aimed to systematically review and meta-analyze the available literature on the association between preterm infant bronchopulmonary dysplasia (BPD) and pre-adulthood asthma.MethodsStudies examining the association between BPD and asthma in children and adolescents were systematically reviewed, and a meta-analysis was conducted. We searched Scopus, Embase, Web of Science, PubMed, and Cochrane Library from the database inception to March 26, 2022. The pooled odds ratio (OR) estimate was used in our meta-analysis to calculate the correlation between BPD and the probability of developing asthma before adulthood. Stata 12.0 was used to conduct the statistical analysis.ResultsThe correlation between asthma and BPD in preterm newborns was examined in nine studies. We used a random effect model to pool the OR estimate. Our results indicated a marked increase in the risk of subsequent asthma in preterm infants with BPD [OR = 1.73, 95% confidence interval (CI) = 1.43-2.09]. Moreover, there was no obvious heterogeneity across the studies (P = 0.617, I2 = 0%). The pooled OR remained stable and ranged from 1.65 (95% CI = 1.35-2.01) to 1.78 (95% CI = 1.43-2.21). Regarding publication bias, the funnel plot for asthma risk did not reveal any noticeable asymmetry. We further performed Begg's and Egger's tests to quantitatively evaluate publication bias. There was no evidence of a publication bias for asthma risk (P > |Z| = 0.602 for Begg's test, and P > |t| = 0.991 for Egger's test).ConclusionsOur findings indicate that preterm infants with BPD have a much higher risk of developing asthma in the future (OR = 1.73, 95% CI = 1.43-2.09). Preterm infants with BPD may benefit from long-term follow-up.