Elevated neutrophil-lymphocyte ratios in extremely preterm neonates with histologic chorioamnionitis

Extracellular Vesicles-mediated recombinant IL-10 protects against ascending infection-associated preterm birth by reducing fetal inflammatory response

Background

Fetal inflammatory response mediated by the influx of immune cells and activation of pro-inflammatory transcription factor NF-κB in feto-maternal uterine tissues is the major determinant of infection-associated preterm birth (PTB, live births < 37 weeks of gestation).

Objective

To reduce the incidence of PTB by minimizing inflammation, extracellular vesicles (EVs) were electroporetically engineered to contain anti-inflammatory cytokine interleukin (IL)-10 (eIL-10), and their efficacy was tested in an ascending model of infection (vaginal administration of E. coli) induced PTB in mouse models.

Study design

EVs (size: 30-170 nm) derived from HEK293T cells were electroporated with recombinant IL-10 at 500 volts and 125 Ω, and 6 pulses to generate eIL-10. eIL-10 structural characters (electron microscopy, nanoparticle tracking analysis, ExoView [size and cargo content] and functional properties (co-treatment of macrophage cells with LPS and eIL-10) were assessed. To test efficacy, CD1 mice were vaginally inoculated with E. coli (1010CFU) and subsequently treated with either PBS, eIL-10 (500ng) or Gentamicin (10mg/kg) or a combination of eIL-10+gentamicin. Fetal inflammatory response in maternal and fetal tissues after the infection or treatment were conducted by suspension Cytometer Time of Flight (CyTOF) using a transgenic mouse model that express red fluorescent TdTomato (mT+) in fetal cells.

Results

Engineered EVs were structurally and functionally stable and showed reduced proinflammatory cytokine production from LPS challenged macrophage cells in vitro. Maternal administration of eIL-10 (10 µg/kg body weight) crossed feto-maternal barriers to delay E. coli-induced PTB to deliver live pups at term. Delay in PTB was associated with reduced feto-maternal uterine inflammation (immune cell infiltration and histologic chorioamnionitis, NF-κB activation, and proinflammatory cytokine production).

Conclusions

eIL-10 administration was safe, stable, specific, delayed PTB by over 72 hrs and delivered live pups. The delivery of drugs using EVs overcomes the limitations of in-utero fetal interventions. Protecting IL-10 in EVs eliminates the need for the amniotic administration of recombinant IL-10 for its efficacy.

Linked Th17 and Calgranulin Responses in Maternal-cord Blood Dyads of Preterm Gestations with Histologic Chorioamnionitis

Introduction

Maternal-fetal immune crosstalk mechanisms are increasingly identified in the pathogenesis of gestational disorders, including histologic chorioamnionitis (HCA). Although an inflammatory Th17 immune phenotype has been described in preterm neonates with HCA, the associated maternal Th17 response is relatively unknown. To refine our understanding of Th17 biology in this context, we examined Th17 responses in maternal-cord blood dyads of preterm gestations.

Materials and methods

Paired maternal and cord blood (CB) samples were prospectively collected from preterm gestations (23-34 weeks) with HCA or controls. Th17-linked cell frequencies and plasma calgranulin (S100A8, S100A12) levels were determined by flow cytometry and enzyme-linked immunoassay, respectively.

Results

Analyses of 47 maternal-cord blood pairs showed striking parallel increases in Th17 cell frequencies as well as plasma calgranulin levels in the presence of fetal inflammation. Cord blood S100A12 levels were directly correlated with Th17 cell frequencies. In CB cultures, rh-S100A12 promoted in vitro propagation of Th17-type CD4+ cells.

Conclusions

Maternal and CB Th17-linked responses are dually amplified in gestations with HCA, supporting a biological role for maternal-fetal interactions in this disorder. In addition to advancing current knowledge of neonatal Th17 mechanisms, these data shed new light on their association with maternal inflammation.

Association of clinical signs of chorioamnionitis with histological chorioamnionitis and neonatal outcomes

BACKGROUND

Chorioamnionitis is a risk factor for fetal and neonatal outcomes. Therefore, predicting histological chorioamnionitis (HCA) and neonatal outcomes using clinical parameters could be helpful in management and preventing morbidities.

OBJECTIVE

To determine if parameters of clinical chorioamnionitis (CCA) would be associated with HCA and neonatal outcomes.

STUDY DESIGN

In this cohort study using a retrospective design, we analyzed the performance of signs of CCA in predicting HCA, and neonatal outcomes. Data were extracted from the electronic health record for all neonates with documented CCA delivered at our institution from 2011 to 2016. We compared our findings based on the old ACOG definition of CCA and the new definition released in 2017 - maternal fever plus any of fetal tachycardia, maternal leukocytosis, and purulent vaginal discharge. Maternal tachycardia and uterine tenderness were removed from the new criteria. Neonatal laboratory samples on admission, 12 h and 24 h were used to define the three time points of neonatal suspected sepsis.

RESULTS

There were 530 mothers-infant dyads with chorioamnionitis. Seventy-three were preterm, and 457 were term. Eighty-eight percent of the preterm mothers had CCA, and HCA was present in 62.5% of 72 preterm placentas. Preterm infants with placental HCA significantly had lower birth weight, gestational age, placental weight, and more infants with lower 5-minute Apgar scores, compared to those with no HCA. In preterm infants, maternal urinary tract infection was significantly associated with decreased odds for HCA (OR 0.22, CI 0.10 - 0.71). More preterm babies with suspected sepsis criteria at the 3 time points had HCA (all p ≤ .01). In the term cohort, 95.4% and 65.6% had CCA and HCA, respectively. In term infants (n = 457), maternal leukocytosis (p = .002) and prolonged rupture of membranes (PROM; p = 002) were associated with HCA. Suspected sepsis was associated with PROM (p = .04), HCA (p = .0001), and maternal leukocytosis (p ≤ .05) in at least 1 of the 3 time points.

CONCLUSION

Though maternal leukocytosis was significantly associated with the presence of HCA in the term cohort, there were no CCA criteria that accurately predicted presence of HCA in either the preterm or the term infants.

Neutrophil-lymphocyte ratio for the prediction of histological chorioamnionitis in cases of preterm premature rupture of membranes: a case-control study

Background

The neutrophil-lymphocyte ratio (NLR) is easily calculated blood test parameter, which can be used as marker to predict many inflammatory disorders. The aim of this study was to assess and compare the NLR in maternal blood with the white blood cell (WBC) count and C-reactive protein (CRP) concentration for the prediction of histological chorioamnionitis.

Methods

This was a case-control study of 137 woman with preterm premature rupture of membranes (PPROM) at a gestational age between 22^+ 0 and 34^+ 6 weeks. Blood samples, collected less than 48 h before delivery and at least 48 h after the administration of corticosteroids, were selected for the analysis. The NLR was calculated by dividing the number of neutrophils by the number of lymphocytes. Chorioamnionitis was diagnosed by the histopathological evaluation of placental membranes and chorionic plate.

Results

Patients with diagnosed histological chorioamnionitis (HCA) had significantly higher levels of WBC, CRP and NLR (p-value < 0.001). Levels of WBC, CRP and NLR predicted HCA with an area under the curve (AUC) of 0.81, 0.81 and 0.89, respectively. NLR had statistically significantly higher AUC than WBC, but no significant difference was found between AUCs of NLR and CRP. The cut-off level of NLR was found to be 5,97, which had a sensitivity of 77 % and a specificity of 95 %.

Conclusion

NLR has a good predictive value for HCA and could be used as an additional diagnostic marker for predicting histological chorioamnionitis in cases with preterm premature rupture of membranes before 34 weeks of gestation.