Clinical chorioamnionitis at term IX: <i>in vivo</i> evidence of intra-amniotic inflammasome activation

Gomez‐Lopez, Nardhy; Romero, Roberto; Maymon, E; Kusanovic, Juan Pedro; Panaitescu, Bogdan; Miller, Derek; Pacora, Percy; Tarca, Adi L.; Motomura, Kenichiro; Erez, Offer; Jung, Eun-Jung; Hassan, Sonia S.; Hsu, Chaur Dong

doi:10.1515/jpm-2018-0271

Cited by 44 publications

(33 citation statements)

References 153 publications

(180 reference statements)

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“…In the current study, we found that preterm PROM patients with a positive culture and intra-amniotic inflammation (diagnosed as the elevated amniotic fluid concentration of IL-6 >2.6 ng/mL) have elevated bacterial burden using 16S rRNA gene qPCR. These results are consistent with previous studies in which women with preterm labor [29,82], clinical chorioamnionitis at term [116] or preterm PROM [31,32] and proven intra-amniotic infection display higher levels of IL-6 than those with intra-amniotic inflammation without detectable microorganisms. Patients with a positive culture do not seem to display differences in the intensity of the intra-amniotic inflammatory response, as evidenced by amniotic fluid IL-6 concentrations.…”

Section: Microbial Detection and Intra-amniotic Infectionsupporting

confidence: 93%

“…Herein, we showed that there is a significant correlation between 16S rRNA gene signal, microbial burden, and extracellular ASC concentrations in amniotic fluid of patients with preterm PROM. Extracellular ASC has been previously utilized as an in vivo indicator of inflammasome activation in amniotic fluid [82,115,116]. Indeed, we have recently demonstrated that the concentrations of this protein are increased in the amniotic cavity during the sterile physiological process of spontaneous labor at term [115], as well as in pathological processes such as clinical chorioamnionitis at term [116] and preterm labor/ birth [82].…”

Section: Microbial Burden Correlated With Intra-amniotic Inflammasomementioning

confidence: 97%

“…Concentrations of extracellular ASC in the amniotic fluid were determined as previously established [82,115,116] by using a sensitive and specific enzyme-linked immunosorbent assay (ELISA) kit obtained from LifeSpan Biosciences (Seattle, WA, USA). Amniotic fluid concentrations of ASC were obtained by interpolation from the standard curve.…”

Section: Determination Of Extracellular Asc In Amniotic Fluidmentioning

confidence: 99%

“…Upon inflammasome activation, ASC proteins are released into the extracellular space where they can serve as a readout of inflammasome activation in vivo [112][113][114]. Indeed, we have previously shown that increased concentrations of extracellular ASC are observed in amniotic fluid from women with spontaneous labor at term [115] and those with clinical chorioamnionitis at term [116] or with preterm labor with intact membranes [82]. However, whether amniotic fluid concentrations of extracellular ASC can provide a readout of the intra-amniotic inflammatory response in women with preterm PROM has not been investigated.…”

Section: Introductionmentioning

confidence: 99%

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Microbial burden and inflammasome activation in amniotic fluid of patients with preterm prelabor rupture of membranes

Theis

Romero

Motomura

et al. 2020

Journal of Perinatal Medicine

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Background Intra-amniotic inflammation, which is associated with adverse pregnancy outcomes, can occur in the presence or absence of detectable microorganisms, and involves activation of the inflammasome. Intra-amniotic inflammasome activation has been reported in clinical chorioamnionitis at term and preterm labor with intact membranes, but it has not yet been investigated in women with preterm prelabor rupture of membranes (preterm PROM) in the presence/absence of detectable microorganisms. The aim of this study was to determine whether, among women with preterm PROM, there is an association between detectable microorganisms in amniotic fluid and intra-amniotic inflammation, and whether intra-amniotic inflammasome activation correlates with microbial burden. Methods Amniotic fluids from 59 cases of preterm PROM were examined for the presence/absence of microorganisms through culture and 16S ribosomal RNA (rRNA) gene quantitative real-time polymerase chain reaction (qPCR), and concentrations of interleukin-6 (IL-6) and ASC [apoptosis-associated spec-like protein containing a caspase recruitment domain (CARD)], an indicator of inflammasome activation, were determined. Results qPCR identified more microbe-positive amniotic fluids than culture. Greater than 50% of patients with a negative culture and high IL-6 concentration in amniotic fluid yielded a positive qPCR signal. ASC concentrations were greatest in patients with high qPCR signals and elevated IL-6 concentrations in amniotic fluid (i.e. intra-amniotic infection). ASC concentrations tended to increase in patients without detectable microorganisms but yet with elevated IL-6 concentrations (i.e. sterile intra-amniotic inflammation) compared to those without intra-amniotic inflammation. Conclusion qPCR is a valuable complement to microbiological culture for the detection of microorganisms in the amniotic cavity in women with preterm PROM, and microbial burden is associated with the severity of intra-amniotic inflammatory response, including inflammasome activation.

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Section: Microbial Detection and Intra-amniotic Infectionsupporting

confidence: 93%

Section: Microbial Burden Correlated With Intra-amniotic Inflammasomementioning

confidence: 97%

Section: Determination Of Extracellular Asc In Amniotic Fluidmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Microbial burden and inflammasome activation in amniotic fluid of patients with preterm prelabor rupture of membranes

Theis

Romero

Motomura

et al. 2020

Journal of Perinatal Medicine

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“…ABSTRACT: Cell-free DNA (cfDNA) in blood, urine and other biofluids provides a unique window into 24 human health. A proportion of cfDNA is derived from bacteria and viruses, creating opportunities for the 25 diagnosis of infection via metagenomic sequencing.…”

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confidence: 99%

Separating the signal from the noise in metagenomic cell-free DNA sequencing

Burnham

Gomez‐Lopez

Heyang

et al. 2019

Preprint

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Cell-free DNA (cfDNA) in blood, urine and other biofluids provides a unique window into 24 human health. A proportion of cfDNA is derived from bacteria and viruses, creating opportunities for the 25 diagnosis of infection via metagenomic sequencing. The total biomass of microbial-derived cfDNA in 26 clinical isolates is low, which makes metagenomic cfDNA sequencing susceptible to contamination and 27 alignment noise. Here, we report Low Biomass Background Correction (LBBC), a bioinformatics noise 28 filtering tool informed by the uniformity of the coverage of microbial genomes and the batch variation in 29 the absolute abundance of microbial cfDNA. We demonstrate that LBBC leads to a dramatic reduction in 30 false positive rate while minimally affecting the true positive rate for a cfDNA test to screen for urinary 31 tract infection. We next performed high throughput sequencing of cfDNA in amniotic fluid collected from 32 term uncomplicated pregnancies or those complicated with clinical chorioamnionitis with and without intra-33 amniotic infection. The data provide unique insight into the properties of fetal and maternal cfDNA in 34 amniotic fluid, demonstrate the utility of cfDNA to screen for intra-amniotic infection, support the view 35 that the amniotic fluid is sterile during normal pregnancy, and reveal cases of intra-amniotic inflammation 36 without infection at term. 37 38 2 Introduction 1 2Metagenomic sequencing of cfDNA offers a highly sensitive approach to screen for pathogens in clinical 3 samples 1-4 . The sensitivity of metagenomic sequencing of cfDNA in plasma can be boosted by the 4 implementation of library preparations optimized to recover short, degraded microbial cfDNA 5 , or by 5 strategies that selectively enrich microbial DNA or deplete host DNA 6-8 . A major remaining challenge is 6the relatively poor specificity of the cfDNA metagenomic sequencing, which is limited by alignment noise, 7annotation errors in reference genomes and environmental contamination 9 . 8 9Here, we report low biomass background correction (LBBC), a tool to filter background contamination and 10 noise in cfDNA metagenomic sequencing datasets. We have applied LBBC to two independent datasets. 11We first re-analyzed a dataset from a previous study that investigated the utility of urinary cfDNA as an 12analyte to monitor urinary tract infection 2 (UTI). Next, we generated a new dataset of cfDNA in amniotic 13 fluid collected from uncomplicated pregnancies or those complicated with clinical chorioamnionitis at term, 14a common heterogeneous condition that can occur in the presence or absence of intra-amniotic infection 10 . 15We report a first, detailed study of the properties of cfDNA in amniotic fluid. For both datasets, detailed 16 microbiologic workups, including results from conventional bacterial culture and/or 16S rRNA sequencing, 17were available to benchmark the LBBC workflow. We demonstrate that LBBC greatly improves the 18 specificity of cfDNA metagenomic sequencing, while minimally affecting its sensitivity. ...

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Cellular immune responses in amniotic fluid of women with preterm clinical chorioamnionitis

Galaz

Romero

et al. 2020

Inflamm. Res.

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Objective: Preterm birth is the leading cause of neonatal morbidity and mortality worldwide. Some preterm births are associated with clinical chorioamnionitis; yet, this condition has been poorly investigated. Herein, we characterized the amniotic fluid cellular immune responses in women with preterm clinical chorioamnionitis.Methods and subjects: Amniotic fluid samples were obtained from women with preterm clinical chorioamnionitis and a positive or negative microbiological culture (n=17). The cellular composition of amniotic fluid was evaluated using fluorescence microscopy, scanning

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Clinical chorioamnionitis at term IX: in vivo evidence of intra-amniotic inflammasome activation

Cited by 44 publications

References 153 publications

Microbial burden and inflammasome activation in amniotic fluid of patients with preterm prelabor rupture of membranes

Microbial burden and inflammasome activation in amniotic fluid of patients with preterm prelabor rupture of membranes

Separating the signal from the noise in metagenomic cell-free DNA sequencing

Cellular immune responses in amniotic fluid of women with preterm clinical chorioamnionitis

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