Publications

Abstract

Group B Streptococcus (GBS) is the major cause of human neonatal infections. A single clone, designated CC17-GBS, accounts for more than 80% of meningitis cases, the most severe form of the infection. However, the events allowing blood-borne GBS to penetrate the brain remain largely elusive. In this study, we identified the host transmembrane receptors α5β1 and αvβ3 integrins as the ligands of Srr2, a major CC17-GBS-specific adhesin. Two motifs located in the binding region of Srr2 were responsible for the interaction between CC17-GBS and these integrins. We demonstrated in a blood-brain-barrier cellular model that both integrins contributed to the adhesion and internalization of CC17-GBS. Strikingly, both integrins were overexpressed during the postnatal period in the brain vessels of the blood-brain barrier and blood-cerebrospinal fluid barrier and contributed to juvenile susceptibility to CC17 meningitis. Finally, blocking these integrins decreased the ability of CC17-GBS to cross into the CNS of juvenile mice in an in vivo model of meningitis. Our study demonstrated that CC17-GBS exploits integrins in order to cross the brain vessels, leading to meningitis. Importantly, it provides host molecular insights into neonate’s susceptibility to CC17-GBS meningitis, thereby opening new perspectives for therapeutic and prevention strategies of GBS-elicited meningitis.

Abstract

Background: The pathogenesis of late-onset sepsis (LOS) in preterm infants is poorly understood and knowledge about risk factors, especially prenatal risk factors, is limited. This study aimed to assess the association between the cause of preterm birth and LOS in very preterm infants.

Methods: 2052 very preterm singletons from a national population-based cohort study alive at 72 h of life were included. Survival without LOS was compared by cause of preterm birth using survival analysis and Cox regression models.

Results: 437 (20.1%) had at least one episode of LOS. The frequency of LOS varied by cause of preterm birth: 17.1% for infants born after preterm labor, 17.9% after preterm premature rupture of membranes, 20.3% after a placental abruption, 20.3% after isolated hypertensive disorders, 27.5% after hypertensive disorders with fetal growth restriction (FGR), and 29.4% after isolated FGR. In multivariate analysis, when compared to infants born after preterm labor, the risk remained higher for infants born after hypertensive disorders (hazard ratio HR = 1.7, 95% CI = 1.2-2.5), hypertensive disorders with FGR (HR = 2.6, 95% CI = 1.9-3.6) and isolated FGR (HR = 2.9, 95% CI = 1.9-4.4).

Conclusion: Very preterm infants born after hypertensive disorders or born after FGR had an increased risk of LOS compared to those born after preterm labor.

Impact: Late-onset sepsis risk differs according to the cause of preterm birth. Compared with those born after preterm labor, infants born very preterm because of hypertensive disorders of pregnancy and/or fetal growth restriction display an increased risk for late-onset sepsis. Antenatal factors, in particular the full spectrum of causes leading to preterm birth, should be taken into consideration to better prevent and manage neonatal infectious morbidity and inform the parents.

Abstract

Purpose: The role of angiotensin receptor blockers (ARB), angiotensin-converting enzyme inhibitors (ACEi), or other antihypertensive agents in the case of Covid-19 remains controversial. We aimed to investigate the association between antihypertensive agent exposure and in-hospital mortality in patients with Covid-19.

Methods: We performed a retrospective multicenter cohort study on patients hospitalized between February 1 and May 15, 2020. All patients had been followed up for at least 30 days.

Results: Of the 8078 hospitalized patients for Covid-19, 3686 (45.6%) had hypertension and were included in the study. In this population, the median age was 75.4 (IQR, 21.5) years and 57.1% were male. Overall in-hospital 30-day mortality was 23.1%. The main antihypertensive pharmacological classes used were calcium channel blockers (CCB) (n=1624, 44.1%), beta-blockers (n=1389, 37.7%), ARB (n=1154, 31.3%), and ACEi (n=998, 27.1%). The risk of mortality was lower in CCB (aOR, 0.83 [0.70–0.99]) and beta-blockers (aOR, 0.80 [0.67–0.95]) users and non-significant in ARB (aOR, 0.88 [0.72–1.06]) and ACEi (aOR, 0.83 [0.68–1.02]) users, compared to non-users. These results remain consistent for patients receiving CCB, beta-blocker, or
ARB as monotherapies.

Conclusion: This large multicenter retrospective of Covid-19 patients with hypertension found a reduced mortality among CCB and beta-blockers users, suggesting a putative protective effect. Our findings did not show any association between the use of renin-angiotensin-aldosterone system inhibitors and the risk of in-hospital death. Although they need to be confirmed in further studies, these results support the continuation of antihypertensive agents in patients with Covid-19, in line with the current guidelines.

Abstract

Objective: To evaluate the causes of MTM and their impact on subsequent pregnancies.

Material and methods: A retrospective single-center cohort study of all pregnancies with a second-trimester pregnancy loss between 14 weeks and 21 weeks + 6 days gestation, excluding terminations of pregnancy (TOP) and in utero fetal deaths. Predefined criteria were used to allocate cases to one of 6 primary etiologic diagnoses: cervical insufficiency, chorioamnionitis, placental anomalies, fetal anomalies, iatrogenic causes, or abdominal trauma.

Results: Among 578 mid-trimester fetal losses, 175 were MTM, a prevalence of 5.7 per 1000 live births in the center. The suspected primary cause was cervical insufficiency in 76 cases (43.4%), chorioamnionitis in 59 (33.7%), placental anomalies or preterm premature rupture of membranes in 26 (14.8%), iatrogenic in 8 (4.6%), trauma in 3 (1.7%), and undetermined in 3 cases (1.7%). A subsequent pregnancy beyond 14 WG was recorded for 78 patients. Recurrent MTM occurred in 21.8% and preterm deliveries in 14.1% ; 13% of patients without evidence of cervical insufficiency in the index pregnancy required emergency cerclage.

Conclusion: Cervical insufficiency was the leading cause of MTM, with a high risk of recurrent MTM or preterm birth, thus prophylactic cerclage or cervical length measurements should be considered for subsequent pregnancies.

Abstract

Group A Streptococcus (GAS), a Gram-positive human-specific pathogen yields 517,000 deaths annually worldwide, including 163,000 due to invasive infections and among them puerperal fever. Before efficient prophylactic measures were introduced, the mortality rate for mothers during childbirth was about 10%; puerperal fever still accounts for over 75,000 maternal deaths annually. Yet little is known regarding the factors and mechanisms of GAS invasion and establishment in postpartum infection. We characterized the early steps of infection in an ex vivo infection model of the human decidua, the puerperal fever portal of entry. Coordinate analysis of GAS behavior and the immune response led us to demonstrate that (i) GAS growth was stimulated by tissue products; (ii) GAS invaded tissue and killed ~50% of host cells within two hours; these processes required SpeB protease and Streptolysin O activities, respectively; (iii) GAS impaired the tissue immune response. Immune impairment occurred both at the RNA level, with only partial induction of the innate immune response, and protein level, in an SLO- and SpeB-dependent manner. Our study indicates that efficient GAS invasion of decidua and the restricted host immune response favored its propensity to develop rapid invasive infections in a gynecological-obstetrical context.

Abstract

Preeclampsia, a hypertensive disorder occurring during pregnancy, is characterized by excessive oxidative stress and trophoblast dysfunction with dysregulation of soluble Fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) production. Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase (Nox) is the major source of placental superoxide in early pregnancy and its activation with the subsequent formation of superoxide has been demonstrated for various agents including Transforming Growth Factor beta-1 (TGF-β1), a well-known p38 MAPK pathway activator. However, the bridge between Nox and sFlt-1 remains unknown. The purpose of this study was to explore the possible signaling pathway of TGF-β1/Nox/p38 induced sFlt-1 production in human chorionic villi (CV).

Methods: Human chorionic villi from first trimester placenta (7-9 Gestational Weeks (GW)) were treated with TGF-β1 or preincubated with p38 inhibitor, SB203580. For NADPH oxidase inhibition, CV were treated with diphenyleneiodonium (DPI). The protein levels of phospho-p38, p38, phospho-Mothers Against Decapentaplegic homolog 2 (SMAD2), and SMAD2 were detected by Western blot. The secretion of sFlt-1 and PlGF by chorionic villi were measured with Electrochemiluminescence Immunologic Assays, and NADPH oxidase activity was monitored by lucigenin method.

Results: We demonstrate for the first time that NADPH oxidase is involved in sFlt-1 and PlGF secretion in first trimester chorionic villi. Indeed, the inhibition of Nox by DPI decreases sFlt-1, and increases PlGF secretions. We also demonstrate the involvement of p38 MAPK in sFlt-1 secretion and Nox activation as blocking the p38 MAPK phosphorylation decreases both sFlt-1 secretion and superoxide production. Nevertheless, TGF-β1-mediated p38 activation do not seem to be involved in regulation of the first trimester placental angiogenic balance and no crosstalk was found between SMAD2 and p38 MAPK pathways.

Conclusions: Thus, the placental NADPH oxidase play a major role in mediating the signal transduction cascade of sFlt-1 production. Furthermore, we highlight for the first time the involvement of p38 activation in first trimester placental Nox activity.

Abstract

Introduction: Retinopathy of prematurity (ROP) is a blinding disease that requires screening by retinal examination. Screening practices are rarely evaluated. We aimed to determine the prevalence of ROP screening in very preterm infants and individual- and center-related factors associated with ROP screening.

Methods: Data were extracted from the EPIPAGE-2 cohort, a French prospective population-based study of premature births in 2011. Children born before 32 weeks’ gestation (WG) without severe malformation and alive at the recommended time for ROP screening were included. Outcome measures were achievement of ROP screening and compliance with recommended screening timeline. Individual- and center-related factors associated with both measures were studied using mixed models.

Results: Among 3,077 eligible infants, 2,169 (70.5%) had a ROP screening, ranging from 96% at 24 WG to 50% at 31 WG. Large variability among units was observed. Individual characteristics associated with screening were low gestational age, low birth weight, severe bronchopulmonary dysplasia or neurological lesions, and transfer between neonatal units during the screening period. Odds of screening were higher in neonatal units using wide-angle imaging (odds ratio 2.65 [95% confidence interval 1.17-6.01]) but decreased in units without a local protocol for ROP screening (0.03 [0.01-0.09]). Among screened children, 1,641/2,169 (75.7%) were screened according to recommended timeline. Delayed screening was associated with low gestational age, severe bronchopulmonary dysplasia or necrotizing enterocolitis, and absence of local protocol for ROP screening.

Discussion/conclusions: In this large cohort study of infants born very preterm, almost one-third were not screened for ROP. Children most at risk for ROP were the best screened but often with delay. The higher compliance of neonatal units using wide-angle imaging systems supports its use.

Abstract

Introduction: While use of augmentation of labor (AL) is appropriate for labor dystocia, it is frequently used inadequately and unnecessarily. The objective was to assess at a national level, the frequency and determinants of misuse of augmentation of labor (AL).

Material and methods: Women of the French perinatal survey of 2016 with a singleton cephalic fetus, delivering at term after a spontaneous labor were included. « Misuse of AL » was defined by artificial rupture of the membranes (ROM) and/or oxytocin within one hour of admission and/or duration between ROM and oxytocin of less than one hour. Women, labor and maternity unit’s characteristics were compared between the « misuse of AL » and « no misuse of AL » groups by bivariate analysis. To identify the determinants of misuse of AL, a multivariable multilevel logistic regression was performed taking into account the data’s hierarchical structure (first level: women, second level: maternity units).

Results: Among the 7196 women included, 1524 (21.2%) had a misuse of AL. The determinants of misuse of AL were middle school educational level (reference high school), aOR = 1.21; 95%CI[1.01-1.45], gestational age at delivery ≥41weeks (reference 39-40 weeks), aOR = 1.19; 95%CI[1.00-1.42], cervical dilation ≥6cm at admission (reference <3cm), aOR = 1.39; 95%CI[1.10-1.76], epidural analgesia aOR = 1.63; 95%CI[1.35-1.96], delivery in a private hospital (reference public teaching hospital), aOR = 2.25; 95%CI[1.57-3.23]; and maternity units with <1000 deliveries/year and 1000-1999 deliveries/year (reference ≥3000 deliveries/year), respectively aOR = 1.52; 95%CI[1.11-2.08] and aOR = 1.42; 95%CI[1.05-1.92]. Less than 3% of the variance was explained by women characteristics, and 24.17% by the maternity units’ characteristics.

Conclusions: In France, one spontaneous laboring woman among five is subject to misuse of AL. The misuse is mostly explained by maternity unit’s characteristics. The determinants identified in this study can be used to implement targeted actions in small and private maternity units.

[Maternal mortality in France 2013-2015: An evolving profile].

Editorial: No abstract available

Editorial : No abstract available