Maternal Serum Cytokines in Preterm Premature Rupture of Membranes

Diagnostic tests for the prediction of histological chorioamnionitis and funisitis in pregnant women with preterm premature rupture of membranes: A systematic review

BACKGROUND

Infection of the amniotic cavity is an important driver and/or consequence of preterm prelabour rupture of membranes (PPROM). Prediction of infection is challenging, limiting guidance for interventions during the antenatal period. Infection typically triggers a host inflammatory response, and non-invasive indirect markers of the maternal or fetal inflammatory response have been reported in the context of PPROM and intra-amniotic infection. Some of these markers have also been tested in amniotic fluid (AF) samples.

AIMS

This study compared markers of the inflammatory response in women with PPROM against the outcome standard of histological chorioamnionitis (HCA) or funisitis (FUS).

METHODS

Searches were conducted for studies reporting diagnostic test sensitivity and specificity for proven HCA or FUS in pregnant women with PPROM after 20 weeks' gestation. Weighted mean pooled sensitivity (Se), specificity (Sp), positive predictive value, negative predictive value, diagnostic odds ratio and 95% confidence intervals were calculated for each of the selected diagnostic tests.

RESULTS

Except ultrasonographic detection of fetal thymic involution, almost all index tests analysed showed relatively low sensitivity. Maternal white cell count, interleukin-6 (IL-6) and AF IL-6 had credible specificity. Testing of AF markers, while more consistent than serum markers, showed no clear diagnostic accuracy improvement.

CONCLUSIONS

There is a clear lack of evidence for the reliability of any individual diagnostic test to assist in the detection of HCA or FUS in women with PPROM. Combining several markers into a predictive model for improved diagnosis may be worth investigating.

Cord blood granulocyte Colony-Stimulating factor level as an optimal predictor of umbilical cord arteritis associated with brain injury at term equivalent age in preterm neonates

OBJECTIVE

The study aimed 1) to evaluate the association between the presence or absence of umbilical cord arteritis (UCA) and the cord blood cytokine levels, and 2) morbidity and mortality of preterm neonates; and 3) to identify predictive markers for UCA of preterm neonates.

STUDY DESIGN

In this single-center retrospective observational cohort study, preterm neonates born at gestational age (GA) < 36 weeks were categorized pathologically according to the severity of intrauterine inflammation; those without UCA as Group 1, those with UCA as Group 2, and those without any intrauterine inflammation as Group 3 (control), and subgroup analyses classified by their GA were performed. We compared morbidity and mortality, and eight representative cytokine levels in cord blood samples between the groups. Subsequently, receiver operating characteristics (ROC) curves for UCA diagnosis for each cytokine were created, and values of areas under the curve (AUC) were calculated to determine the optimal predictive markers.

RESULTS

In total, 105 patients (36, 58, and 11 in Groups 1, 2, and 3, respectively) were included. Multivariate logistic analysis revealed that patients with UCA had higher incidence of brain injury (Odds Ratio [OR] = 8.53, P = 0.0049, 95% Confidence Interval [CI]: 1.91 - 38.0), at term equivalent age in the subgroup analysis with GA < 32 weeks. Although the median value of cord blood granulocyte colony-stimulating factor (G-CSF) was significantly higher in Group 2 than in Group 1 or 3, only the G-CSF level was found to be high in the subgroup analysis with GA < 32 weeks. For UCA diagnosis, the AUC values of G-CSF were the highest among eight cytokines including interleukin 6 (IL-6). These findings were similar in the subgroup analysis with GA < 32 weeks.

CONCLUSIONS

Preterm neonates, especially born at GA < 32 week, had higher morbidity from　brain injury in the group with UCA. The cord blood G-CSF level was highly accurate for predicting UCA and could thus be used as an optimal biomarker.

Cytokine see-saw across pregnancy, its related complexities and consequences

During pregnancy, a woman's immune system adapts to the changing hormonal concentrations, causing immunologic transition. These immunologic changes are required for a full-term pregnancy, preserving the fetus' innate and adaptive immunity. Preterm labor, miscarriage, gestational diabetes mellitus, and pre-eclampsia are all caused by abnormal cytokine expression during pregnancy and childbirth. A disruption in the cytokine balance can lead to autoimmune diseases or microbiologic infections, or to autoimmune illness remission during pregnancy with postpartum recurrence. The cytokine treatments are essential and damaging to the developing fetus. The current review summarizes the known research on cytokine changes during pregnancy and their possible consequences for pregnant women. Studies suggest that customizing medication for each woman and her progesterone levels should be based on the cytokine profile of each pregnant woman. Immune cells and chemicals play an important function in development of the placenta and embryo. During pregnancy, T cells divide and move, and a careful balance between proinflammatory and anti-inflammatory cytokines is necessary. The present review focuses on the mother's endurance in generating fetal cells and the immunologic mechanism involved.

Preterm labor with intact membranes: a simple noninvasive method to identify patients at risk for intra-amniotic infection and/or inflammation

OBJECTIVE

To develop a noninvasive scoring system to identify patients at high risk for intra-amniotic infection and/or inflammation, which would reduce the need for amniocentesis.

METHODS

This prospective cohort study comprised patients admitted with preterm labor and intact membranes (20-34 weeks of gestation) who underwent a transabdominal amniocentesis and for whom concentrations of quantitative cervical fetal fibronectin and of maternal serum C-reactive protein (CRP) were determined. Intra-amniotic infection was defined as a positive amniotic fluid culture for microorganisms. Intra-amniotic inflammation was defined as an amniotic fluid matrix metalloproteinase-8 concentration >23 ng/mL. Multivariate logistic regression analysis was performed to identify intra-amniotic infection/inflammtion with noninvasive parameters that had a significant relationship with univariate analysis. With four parameters identified by multivariate analysis, we generated a noninvasive risk scoring system.

RESULTS

Of the study population consisting of 138 singleton pregnant women, (1) the overall rate of intra-amniotic infection/inflammation was 28.3% (39/138); (2) four parameters were used to develop a noninvasive risk scoring system [i.e. cervical fetal fibronectin concentration (score 0-2), maternal serum CRP concentration (score 0-2), cervical dilatation (score 0-2), and gestational age at presentation (score 0-1)]; the total score ranges from 0 to 7; 3) the area under the curve of the risk score was 0.96 (95% confidence interval (CI), 0.92-0.99), significantly higher than that of each predictor in the identification of intra-amniotic infection/inflammation (p < .001, for all); 4) the risk score with a cutoff of 4 had a sensitivity of 94.9% (37/39), a specificity of 90.9% (90/99), a positive predictive value of 80.4% (37/46), a negative predictive value of 97.8% (90/92), a positive likelihood ratio of 10.4 (95% CI, 5.6-19.5), and a negative likelihood ratio of 0.06 (95% CI, 0.15-0.22) in the identification of intra-amniotic infection/inflammation.

CONCLUSIONS

(1) The combination of four parameters (concentrations of cervical fetal fibronectin and maternal serum CRP, cervical dilatation, and gestational age) was independently associated with intra-amniotic infection and/or inflammation; and (2) the risk scoring system comprised of the combination of 4 noninvasive parameters was sensitive and specific to identify the patients at risk for intra-amniotic infection and/or inflammation.

Plasma proteomic analysis to identify potential biomarkers of histologic chorioamnionitis in women with preterm premature rupture of membranes

Introduction

To identify potential biomarkers in the plasma that could predict histologic chorioamnionitis (HCA) in women with preterm premature rupture of membranes (PPROM), using shotgun and targeted proteomic analyses.

Methods

This retrospective cohort study included 78 singleton pregnant women with PPROM (24–34 gestational weeks) who delivered within 96 h of blood sampling. Maternal plasma samples were analyzed by label-free liquid chromatography-tandem mass spectrometry for proteome profiling in a nested case-control study design (HCA cases vs. non-HCA controls [n = 9 each]). Differential expression of 12 candidate proteins was assessed by multiple reaction monitoring-mass spectrometry (MRM-MS) analysis in individual plasma samples from cases and controls matched by gestational age at sampling (n = 40, cohort 1). A validation study was further performed in an independent study group (n = 38, cohort 2) using ELISA and turbidimetric immunoassay for three differentially expressed proteins.

Results

Shotgun proteomics analyses yielded 18 proteins that were differentially expressed (P < 0.05) between HCA cases and non-HCA controls. MRM-MS analysis of 12 differentially expressed proteins further revealed that the CRP, C4A, and SAA4 levels were significantly increased in women with HCA. A multi-marker panel comprising plasma SAA4 and C4A showed enhanced potential for differentiating HCA from non-HCA women (area under the curve = 0.899). Additional validation of these findings by ELISA assays revealed that the CRP levels were significantly higher in women with HCA than in those without HCA, whereas the plasma levels of C4A and SAA4 did not significantly differ between the two groups.

Conclusions

Plasma C4A, SAA4, and CRP were identified as potential biomarkers for detecting HCA in women with PPROM, based on targeted and shotgun proteomic analyses, showing good accuracy when used as a combined dual-biomarker panel (C4A and SAA4). Nevertheless, ELISA validation of these proteins, except for CRP, may not yield clinically useful markers for predicting HCA.

Longitudinal evaluation of azithromycin and cytokine concentrations in amniotic fluid following one-time oral dosing in pregnancy

To utilize noninvasive collection of amniotic fluid in the setting of preterm premature rupture of membranes (PPROMs) to report the time concentration profile of azithromycin in amniotic fluid over 7 days from a single dose, and evaluate the correlation between azithromycin concentration and inflammatory markers in amniotic fluid. Prospective cohort study of five pregnant patients admitted with PPROMs and treated with a single 1 g oral azithromycin dose. Amniotic fluid was collected from pads and used to quantify azithromycin concentration as well as TNFa, IL-1a, IL-1b, IL-6, IL-8, and IL-10 concentrations. Primary outcome was time/concentration profile of azithromycin in amniotic fluid. Secondary outcome included correlation between azithromycin concentration and cytokine concentrations. Five patients were enrolled. Mean gestational age on admission with PPROM was 27.5 ± 2.3 weeks with a median latency of 7 days (interquartile range [IQR] = 4-13). A median of two samples/day (IQR = 1-3) were collected per participant. Azithromycin was quantified in duplicate; intra-assay coefficient of variation was 17%. Azithromycin concentration was less than 60 ng/ml after day 3. Azithromycin concentration was positively correlated with IL-8 (r = 0.38, p = 0.03), IL1a (r = 0.39, p = 0.03), and IL-1b (r = 0.36, p = 0.04) in amniotic fluid. Azithromycin is detectable in amniotic fluid over 7 days from a single 1 g maternal dose, however, it is not sustained over the range of minimum inhibitory concentration for common genitourinary flora. Based on correlation with specific cytokines, azithromycin penetration in amniotic fluid may relate to maternal monocyte concentration in amniotic fluid in the setting of PPROM.

Using principal component analysis to examine associations of early pregnancy inflammatory biomarker profiles and adverse birth outcomes

OBJECTIVE

Inflammation as a risk factor for preterm birth is well-established. The primary objective of this analysis was to examine whether individual cytokines versus a composite indicator of mid-pregnancy inflammation are significantly associated with risk for adverse birth outcomes.

STUDY DESIGN

A multi-site prospective study was conducted in a socio-demographically diverse cohort of 610 pregnant participants. At a study visit between 12 and 20 6/7 weeks' gestation, low-grade inflammation was measured via log-transformed serum concentrations of the biomarkers IFN-γ, IL-10, IL-13, IL-6, IL-8, TNF-α, and CRP. Principal component analysis (PCA) was used to identify underlying dimensions of inflammatory activity from the seven biomarkers measured. Gestational age and birth weight at delivery were obtained from medical chart review. The associations between inflammatory profiles and birth outcomes were assessed via linear and logistic regression models. Results were compared with those from individual inflammatory biomarkers, and model fit was assessed using Akaike's Information Criterion (AIC).

RESULTS

Principal component analysis analysis yielded a two-factor solution, with the first factor (IF1) composed of IL-8, IL-10, IL-13, IFN-ɣ, and TNF-α, and the second factor (IF2) containing IL-6 and CRP. When adjusted for race, education, BMI, smoking status, gestational age at time of blood draw, and study site, a one standard deviation (SD) increase in IF1 remained significantly associated with a decrease in standardized gestational age (β = -.13, 95% CI: -.21, -.05) and an increase in odds of preterm delivery (OR = 1.46, 95% CI: 1.13, 1.88) (Table 3). A one SD increase in IF2 was similarly associated with a decrease in standardized gestational age at delivery (β = -.13, 95% CI: -.23, -.04) and an increase in odds of preterm delivery (OR: 1.46, 95% CI: 1.04, 2.05). Neither IF1 nor IF2 was associated with measures of fetal growth. AIC identified that IL-6 was a slightly better fit for length of gestation compared to either composite measure, though all performed similarly.

CONCLUSION

Independent of known sociodemographic risk factors, an elevated mid-pregnancy inflammatory profile was associated with a nearly 50% increase in odds of preterm delivery. The composite performed similarly to IL-6. These results suggest that maternal low-grade inflammation is a risk factor for preterm delivery, and that mid-pregnancy inflammatory biomarkers may be useful in predicting risk for preterm delivery.

Association between dietary inflammatory index and gestational diabetes mellitus risk in a prospective birth cohort study

OBJECTIVE

Information is limited regarding the possible relationship between diet-related inflammation and the risk of gestational diabetes mellitus (GDM). This study investigated the association between the inflammatory potential of the diet, measured by the dietary inflammatory index (DII), and GDM risk in pregnant Chinese women.

METHODS

This study included 2639 eligible women from the Tongji Maternal and Child Health Cohort. Dietary intake was assessed by a validated semiquantitative food frequency questionnaire and was used to calculate the DII score. The DII was then validated using C-reactive protein measurements in a subsample of 133 pregnant women. GDM diagnoses were collected from medical records based on the results of a 75 g oral glucose tolerance test at 24 to 28 wk gestation. Multivariable-adjusted logistic regression models were performed to estimate the odds ratios (ORs) for GDM risk by DII score, modeled continuously and in tertiles.

RESULTS

Of the 2639 participants, 13.1% were diagnosed with GDM. DII scores ranged from -4.45 to 3.15 and were positively associated with C-reactive protein (adjusted β : 1.28, 95% confidence interval [CI]: 0.16, 2.40; P trend = 0.023) when comparing DII tertile 3 (most pro-inflammatory) to tertile 1 (most anti-inflammatory). A significant and positive association was observed between DII scores and GDM risk (adjusted OR: 1.43; 95% CI: 1.05, 1.95; P trend = 0.022) comparing the highest versus lowest tertiles. The stratified analysis showed that this association was stronger in pregnant women who were overweight or obese before pregnancy (adjusted OR: 2.20; 95% CI: 1.03, 4.69).

CONCLUSIONS

These findings suggest that a higher DII score, corresponding to a more proinflammatory diet, is associated with a higher risk of GDM, particularly in pregnant women who were overweight or obese before pregnancy.

Epigenetic age and pregnancy outcomes: GrimAge acceleration is associated with shorter gestational length and lower birthweight

BACKGROUND

Advanced biological aging, as measured by epigenetic aging indices, is associated with early mortality and morbidity. Associations between maternal epigenetic aging indices in pregnancy and pregnancy outcomes, namely gestational length and birthweight, have not been assessed. The purpose of this study was to examine whether epigenetic age during pregnancy was associated with gestational length and birthweight.

RESULTS

The sample consisted of 77 women from the Los Angeles, CA, area enrolled in the Healthy Babies Before Birth study. Whole blood samples for DNA methylation assay were obtained during the second trimester (15.6 ± 2.15 weeks gestation). Epigenetic age indices GrimAge acceleration (GrimAgeAccel), DNAm PAI-1, DNAm ADM, and DNAm cystatin C were calculated. Gestational length and birthweight were obtained from medical chart review. Covariates were maternal sociodemographic variables, gestational age at blood sample collection, and pre-pregnancy body mass index. In separate covariate-adjusted linear regression models, higher early second trimester GrimAgeAccel, b(SE) = - .171 (.056), p = .004; DNAm PAI-1, b(SE) = - 1.95 × 10-4 (8.5 × 10-5), p = .004; DNAm ADM, b(SE) = - .033 (.011), p = .003; and DNAm cystatin C, b(SE) = 2.10 × 10-5 (8.0 × 10-5), p = .012, were each associated with shorter gestational length. Higher GrimAgeAccel, b(SE) = - 75.2 (19.7), p < .001; DNAm PAI-1, b(SE) = - .079(.031), p = .013; DNAm ADM, b(SE) = - 13.8 (3.87), p = .001; and DNAm cystatin C, b(SE) = - .010 (.003), p = .001, were also associated with lower birthweight, independent of gestational length.

DISCUSSION

Higher maternal prenatal GrimAgeAccel, DNAm PAI-1, DNAm ADM, and DNAm cystatin C were associated with shorter gestational length and lower birthweight. These findings suggest that biological age, as measured by these epigenetic indices, could indicate risk for adverse pregnancy outcomes.

Sleep disturbances and inflammatory gene expression among pregnant women: Differential responses by race

Excessive inflammation in pregnancy predicts adverse birth outcomes, including shortened gestational length and lower birthweight, with African American women at greater risk. As substantial racial disparities in sleep quality, and evidence that African Americans have increased vulnerability for sleep-induced inflammatory dysregulation, sleep may be a critical, modifiable health behavior that contributes to racial disparities in birth outcomes. The present study examined sleep disturbance as a predictor of genome-wide transcriptome profiles of peripheral blood samples from 103 pregnant women (33 African American, 70 white) assessed at 18.7 ± 7.2 weeks gestation. We hypothesized that pregnant women with significant sleep disturbances would have gene expression profiles indicating over-expression of inflammatory pathways, with greater effects among African American compared to white women. Promoter-based bioinformatics analyses of differentially expressed genes indicated greater activation of NF-кB, AP1, and CREB transcription factors among African American women with sleep disturbances (all p < 0.05), and enhanced activation of AP1, but not NF-кB and reduced CREB activity among white women with sleep disturbances (p < 0.05). Differences in glucocorticoid receptor (GR) activity were also observed, in which African American women with sleep disturbances had reduced GR activity (p < 0.05), but white women with sleep disturbances showed a trend for enhanced GR activity (p = 0.11). Similarly, Interferon Response Factor (IRF) activity was reduced in African American women while increased in white women with sleep disturbances (p < 0.05). The current study provides novel evidence for gene expression related to inflammation, glucocorticoids, and anti-viral immunity among pregnant women with sleep disturbances, with differential effects by race. African Americans showed greater breadth and magnitude in these proinflammatory and anti-viral pathways than whites, with divergence in anti-inflammatory glucocorticoid, proinflammatory adrenergic-mediated cAMP, and anti-viral interferon responses. These data elucidate the role of sleep disturbances in intracellular inflammatory and anti-viral immunity in pregnancy and provide a potential target for intervention.

Metformin and insulin treatment of gestational diabetes: effects on inflammatory markers and IGF-binding protein-1 - secondary analysis of a randomized controlled trial

Background

Gestational diabetes mellitus (GDM) is characterized by disturbed glucose metabolism and activation of low-grade inflammation. We studied whether metformin treatment has favorable or unfavorable effects on inflammatory markers and insulin-like growth factor-binding protein 1 (IGFBP-1) in GDM patients compared with insulin, and whether these markers associate with major maternal or fetal clinical outcomes.

Methods

This is a secondary analysis of a previous randomized controlled trial comparing metformin (n = 110) and insulin (n = 107) treatment of GDM. Fasting serum samples were collected at the time of diagnosis (baseline, mean 30 gestational weeks [gw]) and at 36 gw. Inflammatory markers serum high-sensitivity CRP (hsCRP), interleukin-6 (IL-6), matrix metalloproteinase-8 (MMP-8) and glycoprotein acetylation (GlycA) as well as three IGFBP-1 phosphoisoform concentrations were determined.

Results

In the metformin and insulin groups combined, hsCRP decreased (p = 0.01), whereas IL-6 (p = 0.002), GlycA (p < 0.0001) and all IGFBP-1 phosphoisoforms (p < 0.0001) increased from baseline to 36 gw. GlycA (p = 0.02) and non-phosphorylated IGFBP-1 (p = 0.008) increased more in patients treated with metformin than those treated with insulin. Inflammatory markers did not clearly associate with pregnancy outcomes but non-phosphorylated IGFBP-1 was inversely associated with gestational weight gain.

Conclusions

Metformin had beneficial effects on maternal serum IGFBP-1 concentrations compared to insulin, as increased IGFBP-1 related to lower total and late pregnancy maternal weight gain. GlycA increased more during metformin treatment compared to insulin. The significance of this observation needs to be more profoundly examined in further studies. There were no evident clinically relevant relations between inflammatory markers and pregnancy outcome measures.

Trial registration

The trial comparing metformin and insulin treatment was registered in ClinicalTrials.gov (NCT01240785) November 3, 2010. Retrospectively registered.

Maternal inflammatory markers for chorioamnionitis in preterm prelabour rupture of membranes: a systematic review and meta-analysis of diagnostic test accuracy studies

BACKGROUND

There is no consensus on the role of inflammatory markers in identifying chorioamnionitis in preterm prelabour rupture of membranes (PPROM). We set out to evaluate the accuracy of maternal blood C-reactive protein (CRP), procalcitonin and interleukin 6 (IL6) in diagnosis of histological chorioamnionitis and/or funisitis (HCA/Funisitis) in PPROM.

METHODS

We searched MEDLINE, EMBASE and The Cochrane Library from inception to January 2020 for studies where maternal blood CRP, procalcitonin or IL6 was assessed against a reference standard of HCA/Funisitis in PPROM. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool was used to assess methodological quality. Hierarchical summary receiver operating characteristic (SROC) models were used to construct summary curves. Bivariate models were used to obtain summary estimates for studies with the same cut-off.

RESULTS

We included 23 studies reporting HCA/Funisitis in 902 of 1717 women, median prevalence 50% (inter-quartile range 38-57). Of these studies, 20 were prospective cohort design and 3 were retrospective cohort. Eleven studies reported the index test against a reference standard of HCA and/or funisitis, 10 reported HCA alone and 2 reported funisitis alone. Many studies had high risk of bias scores on the QUADAS-2 assessment but low concerns for applicability. Sensitivity and specificity for CRP ≥ 20 mg/L (5 studies, 252 participants) was 59% (95% CI 48-69) and 83% (95% CI 74-89) respectively. SROC curves are provided for each index test. At selected specificity of 80%, the sensitivities for CRP (all cut-offs, 17 studies, 1404 participants), PCT ( all cut-offs, 6 studies, 231 participants) and IL6 (all cut-offs, 5 studies, 299 participants) were 59%(95% CI 52-68), 56%(95% CI 50-69) and 52% (95% CI 50-86) respectively.

CONCLUSIONS

There is insufficient evidence to support use of CRP, procalcitonin or IL6 in maternal blood for diagnosis of HCA/Funisitis in PPROM. This review followed recommended methodology and data analytic methods that made the most of the data regardless of the different cut-offs used. However, the evidence is based on few studies with generally small sample sizes, poor-quality scores and substantial heterogeneity. There is a need for good-quality diagnostic accuracy studies to better assess the role of these biomarkers in PPROM.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42015023899, registered on 8 October 2015.

Relationship between dietary inflammatory index, hs-CRP level in the second trimester and neonatal birth weight: a cohort study

The aim of this study was to investigate whether diet plays a role in the effect of inflammation on birth weight. The normal pre-pregnancy body mass index and healthy single pregnant women without classical inflammatory were recruited at 16-20 weeks of pregnancy and provided blood sample to measure plasma high sensitive C-reactive protein (hs-CRP) level. The Dietary Inflammatory Index (DII) score was calculated by a three-day 24 h recall method, and a cohort of 307 eligible pregnant women was established. According to birth weight, the subjects were divided into three groups: normal birth weight (NBW) group, low birth weight (LBW) group, and high birth weight (HBW) group. The hs-CRP level and DII score were significantly different between NBW and LBW groups. The risk of higher hs-CRP in the pro-inflammatory dietary group was 1.89 times than the control group (95% CI: 1.05, 3.42). The risk of LBW with higher hs-CRP was 3.81 times than normal hs-CRP (95% CI: 1.26, 11.56). The risk of LBW in the pro-inflammatory dietary group was 10.44 times than in the anti-inflammatory dietary group (95%CI: 1.29, 84.61). The pro-inflammatory dietary in the second trimester affects the hs-CRP level, showing a positive correlation. And both of two factors increase the risk of LBW.

Telomere Length and Telomerase Activity in Foetal Membranes from Term and Spontaneous Preterm Births

The reduction of telomere length, the protective cap structures of chromosomes, is one of the biomarkers of senescence (a mechanism of ageing), and ageing of foetal gestational tissues is associated with both term and preterm parturition. A mechanism regulating telomere length is the activity of telomerase, an enzyme that adds telomere fragments during DNA replication and cell division; however, its role in regulating telomere length is not well studied in gestational tissues. The objective of this study is to correlate telomere length and telomerase activity in foetal membranes from term and spontaneous preterm births. Foetal membrane samples were collected from pregnant women experiencing term labour (TL), term not in labour (TNL), preterm premature rupture of membranes (pPROM) and spontaneous preterm labour (PTL) with intact membranes (n = 20/group). Telomere length and telomerase activity were analyzed by relative quantification (T/S), real-time PCR and PCR-based fluorometric detection, respectively. Data were analyzed by ANOVA or the Kruskal-Wallis test. Demographic variables were not statistically different among the groups. Foetal membranes from the TL group showed telomere length reduction compared with those from the others (p < 0.0002). Telomerase activity did not change in foetal membranes irrespective of pregnancy outcome. Telomere shortening in foetal membranes is suggestive of senescence associated with triggering of labour at term; however, this is likely independent of telomerase activity, while prematurity may be associated with senescence, but due to other mechanisms than telomere length reduction in foetal membranes.

Pro-inflammatory immune cell gene expression during the third trimester of pregnancy is associated with shorter gestational length and lower birthweight

PROBLEM

Altered maternal immune function predicts risk for shorter gestation and low birthweight. Few studies examine associations between prenatal immune cell gene expression and gestational length or birthweight. No studies examine which cell types drive associations. The purpose of this study is to explore associations between peripheral blood immune cell gene expression and gestational length and birthweight, using transcript origin analysis.

METHOD OF STUDY

Eighty-nine women were drawn from the Community Child Health Network cohort. Third trimester maternal dried blood spots were used for genome-wide transcriptional (mRNA) profiling. Gestational length and birthweight were obtained from medical charts. Covariates were age, race/ethnicity, pre-pregnancy body mass index, smoking, gestational age at blood sampling, and pregnancy infections. Associations between gene expression profiles and gestational length and birthweight were tested using general linear models. The Transcription Element Listening System (TELiS) bioinformatics analysis quantified upstream transcription factor activity. Transcript origin analysis identified leukocyte subsets mediating observed effects.

RESULTS

Shorter gestation was predicted by increased NF-kB (TFBM ratio = -0.582 ± 0.172, P < .001) and monocyte activity (diagnosticity score = 0.172 ± 0.054, P < .001). Longer gestation was associated with increased dendritic cell activity (diagnosticity score = 0.194 ± 0.039, P < .001). Increased AP-1 activity predicted lower birthweight (TFBM ratio = -0.240 ± 0.111, P = .031). Dendritic cells and CD4+ and CD8+ T cells predicted birthweight-related gene expression differences (diagnosticity score P's < 0.021).

CONCLUSION

Higher third trimester pro-inflammatory gene expression predicted shorter gestation and lower birthweight. Variations in monocyte and dendritic cell biology contributed to both effects, and T-cell biology contributed to higher birthweight. These analyses clarify the role of myeloid/lymphoid lineage immune regulation in pregnancy outcomes.

Serum multiple cytokines for the prediction of spontaneous preterm birth in asymptomatic women: A nested case-control study

BACKGROUND

Current biomarkers such as fetal fibronectin and cervical length are accurate predictors of spontaneous preterm birth (sPTB) in women with clinically suspected preterm risk; however, these are not effective for predicting the risk of sPTB in asymptomatic women. Therefore, we performed this study with the objective of determining whether the combinations of specific serum cytokines could accurately predict the sPTB risk in asymptomatic women.

METHODS

We conducted a nested case-control study with 129 incident sPTB cases and 258 individually matched controls who participated in an ongoing birth cohort study. The maternal serum levels of the selected 35 cytokines were measured. We evaluated the relationship between the multiple cytokines and sPTB risk using conditional logistic regression and elastic net model.

RESULTS

A panel of cytokines was significantly associated with an increased risk of sPTB. The odds ratio (OR) of sPTB per standard deviation (SD) increase of the predictive model score was 1.57 (95% CI 1.25-1.97) for the cytokines model. The combination of the selected serum cytokines was substantially more effective in predicting the risk for sPTB, as the receiver-operator characteristic curve (AUC) values were 0.546 and 0.559 in the single cytokine model and it improved to 0.642 in the multiple cytokines model (PAUC difference = 0.02 for TNF-α vs. multiple cytokines; PAUC difference = 0.05 for TRAIL vs. multiple cytokines). Moreover, the prediction was more accurate in overweight pregnant women, with an AUC = 0.879.

CONCLUSIONS

The current study suggested that the combination of selected serum cytokines can more effectively predict the risk of sPTB in asymptomatic women compared with the use of single cytokine.

Antibody Microarray Analysis of Plasma Proteins for the Prediction of Histologic Chorioamnionitis in Women With Preterm Premature Rupture of Membranes

We aimed to identify maternal blood biomarkers predictive of histologic chorioamnionitis (HCA) in the plasma of women with preterm premature rupture of membranes (PPROM) and to determine whether the combination of these biomarkers with conventional clinical variables can improve the prediction of HCA. This retrospective cohort study included 82 consecutive women with PPROM (23-34 gestational weeks) who delivered within 96 hours of blood sampling. A membrane-based human antibody microarray was used to analyze the plasma proteome. The validation of 5 candidate biomarkers of interest was performed by enzyme-linked immunosorbent assay (ELISA) in the final cohort (n = 82). Serum C-reactive protein (CRP) levels were measured at sampling. Seventy-nine molecules studied exhibited intergroup differences. Validation by ELISA confirmed higher levels of plasma matrix metalloproteinase-9 (MMP-9), interleukin-6 (IL-6), S100 A8/A9, and insulin-like growth factor-binding protein 1 (IGFBP-1), but not tissue inhibitor of metalloproteinase 1 (TIMP-1), in women with HCA than in women without HCA. Using a stepwise regression analysis, a combined prediction model was developed, which included the plasma MMP-9, serum CRP levels, and gestational age (area under the curve [AUC], 0.932). The AUC for this model was significantly greater than that for any single variable included in the predictive model. Protein-antibody microarray technology can be useful in identifying plasma-based predictors for HCA. This study suggests that plasma MMP-9, IL-6, IGFBP-1, and S100 A8/A9 are important noninvasive predictors for HCA in women with PPROM and that the best predictive model, which combined these biomarkers with conventional clinical factors, can significantly improve the predictability for HCA.

Elevated pro-inflammatory gene expression in the third trimester of pregnancy in mothers who experienced stressful life events

BACKGROUND

Stress exposure is associated with risk for adverse pregnancy outcomes, potentially in part through dysregulated immune and inflammatory activity. Evidence suggests that stress during pregnancy is associated with inflammation during pregnancy, consistent with risk for preterm birth. However, research has not tested whether complementary changes are reflected in immune cell gene expression, or upstream regulation of inflammation. The purpose of this study was to test associations between preconception and prenatal stress exposure and third trimester immune cell gene expression, focusing specifically on sets of genes previously linked to stress in non-pregnant samples: Pro-inflammatory genes, and antiviral and antibody genes.

METHODS

A sample of 116 low-income, diverse women was recruited from 5 U.S. sites by the Community Child and Health Network at the birth of a child. This study is of the subgroup of women who became pregnant again over the two-year follow-up period, and provided information on stressful life events that occurred both preconception and during the third trimester of the subsequent pregnancy. Dried blood spots (DBS) were collected in the third trimester of pregnancy, and used for gene expression analysis.

RESULTS

Women with more prenatal stressful life events had higher expression of pro-inflammatory genes when compared to those with fewer life events, and the effect was driven by increased activation of pro-inflammatory transcription factors, NF-κB and AP-1. Preconception stressful life event exposure was not associated with gene expression profiles. When entered into models simultaneously, only prenatal stressful life events were associated with up-regulation of pro-inflammatory genes. No differences between high or low stress groups emerged for antiviral or antibody genes.

CONCLUSIONS

Prenatal stress exposure was associated with up-regulated pro-inflammatory gene expression during pregnancy, and increased activity of NF-κB and AP-1. In contrast, stress occurring preconception was not associated with gene expression. These results are consistent with the hypothesis that stress-induced activation of pro-inflammatory transcriptional pathways in pregnancy, but not earlier, may increase risk for inflammation-driven adverse pregnancy outcomes.

Cytokine Changes in Maternal Peripheral Blood Correlate With Time-to-Delivery in Pregnancies Complicated by Premature Prelabor Rupture of the Membranes

Premature prelabor rupture of the membranes (PPROM) causes one-third of preterm births worldwide and is most likely caused by subclinical intrauterine infection and/or inflammation. We proposed that women with systemic inflammation at the time of PPROM would have shorter latency. Peripheral blood samples were collected from 20 singleton pregnant women with PPROM between 23 ± 1 and 33 ± 6 weeks. The first sample was drawn within 48 hours of admission, followed by weekly blood draws until delivery. Pregnancies complicated with acute chorioamnionitis, preeclampsia, intrauterine growth restriction, obesity, substance abuse, and chronic maternal disease were excluded. Twenty uncomplicated, gestational age-matched pregnancies served as controls. Plasma concentration of 39 cytokines was measured longitudinally using Luminex assays to investigate their value as predictive biomarkers of latency. Women with PPROM exhibited significantly lower plasma concentration of interferon-γ-inducible protein 10-Chemokine (c-x-c motif; IP10/CXCL10), Chemokine (c-x-c motif) Ligand 9 (MIG/CXCL9), Platelet-derived growth factor BB (PDGFbb), and cutaneous T cell-attracting chemokine, also known as CCL27/CCL27 than controls at admission but significantly elevated interleukin (IL)1RA, tumor necrosis factor α, monocyte chemotactic protein-1/CCL2 at delivery compared to admission. Women with PPROM who delivered within 7 days had significantly lower plasma concentration of anti-inflammatory cytokine IL1RA than those with latency periods >7 days. The IL1RA and endotoxin activity in conjunction with clinical parameters results in excellent prediction of latency to delivery (area under the receiver-operating characteristic curve = 0.91). We concluded that higher levels of anti-inflammatory cytokines in women with PPROM were associated with increased latency until delivery, likely due to counterbalancing of proinflammatory load. When used in conjunction with other predictive characteristics of time until delivery, cytokines may further assist clinical decision-making and optimize pregnancy outcomes in women with PPROM.

Maternal Stress Potentiates the Effect of an Inflammatory Diet in Pregnancy on Maternal Concentrations of Tumor Necrosis Factor Alpha

Maternal inflammation during pregnancy is known to adversely impact fetal development, birth outcomes, and offspring physical and mental health. Diet and stress have been identified as important determinants of inflammation, yet their combined effects have not been examined in the context of pregnancy. The aim of this study was to examine the relationship between maternal diet with inflammatory potential and psychological stress, and to determine their interaction effect on concentrations of tumor necrosis factor (TNF)-α across pregnancy. We conducted a prospective longitudinal study of n = 202 women with three assessments during pregnancy, which included: ecological momentary assessment (EMA) of maternal stress using the perceived stress scale (PSS) short version; 24-h dietary recalls from which the dietary inflammatory index (DII) was computed; and serum measurements of TNF-α. Across pregnancy, higher perceived stress was associated with consumption of a more pro-inflammatory diet (r = 0.137; p < 0.05). In a linear regression model adjusted for covariates, DII was positively associated with TNF-α (B = 0.093, p = 0.010). The effect of the pro-inflammatory diet on concentrations of TNF-α was more pronounced in women reporting higher levels of stress (B = 0.134, p = 0.018 for DII*PSS interaction). These results highlight the need to consider nutrition and stress concurrently in the context of inflammation during pregnancy.

Accuracy of several maternal seric markers for predicting histological chorioamnionitis after preterm premature rupture of membranes: a prospective and multicentric study

OBJECTIVE

To assess and compare several maternal seric markers for the prediction of histological chorioamnionitis (HCA) after preterm premature rupture of membranes (PPROM). Study design A prospective and multicentric observational study was undertaken, including six French tertiary referral centres. Pregnant women over 18 years, with PPROM between 22+0 and 36+6 WG were enrolled. A blood sample was obtained before delivery and analysed for C-Reactive Protein (CRP), InterCellular Adhesion Molecule-1 (ICAM-1), Interleukin-6 (IL-6), Interleukin-8 (IL-8), Matrix-Metalloproteinase 8 and 9 (MMP-8, MMP-9), Triggering receptor on myeloid cells (TREM-1), and Human Neutrophile Peptides (HNP). HCA was determined by histological examination distinguishing maternal from fetal inflammatory response. Placental analyses and biological assays were performed in duplicate. Comparison of maternal seric markers levels in women with or vs. without HCA was performed, using a non-parametric Receiver Operating Characteristic.

RESULTS

295 women were kept for analysis. The prevalence of HCA was 42.7% (126/295). The concentrations of MMP-8, MMP-9, HNP and CRP were higher in HCA vs. the non-HCA group (P<0.05) whereas the concentrations of ICAM- 1, IL-6, IL-8 were not different (P>0.05). The ROC curve with the largest AUC was for CRP (AUC; 0.70; 95% CI; 0.64-0.77) and it was significantly higher than those for MMP-8, MMP-9, or HNP (P<0.03).

CONCLUSION

CRP was the best maternal marker for predicting HCA in women with PPROM.

Cytokines in noninvasively obtained amniotic fluid as predictors of fetal inflammatory response syndrome

BACKGROUND

In patients with preterm premature rupture of membranes, intrauterine inflammation and/or infection is frequently present, can lead to fetal inflammatory response syndrome, and is associated with adverse neonatal outcome. Clinical decision making requires balancing the potential benefits of pregnancy prolongation against the risk of intrauterine infection. Diagnostic tests in maternal serum are of moderate prediction value and amniocentesis is an invasive procedure. Therefore, markers obtained noninvasively would be helpful in patients with expectant management.

OBJECTIVES

To determine the predictive values of amniotic fluid interleukin-6 and tumor necrosis factor-α in vaginal secretions for fetal inflammatory response syndrome and/or histologic funisitis and for adverse neonatal outcome in patients with preterm premature rupture of membranes.

STUDY DESIGN

In this prospective multicenter case-control study, vaginal secretions were sampled daily with a noninvasive method from 99 women with preterm premature rupture of membranes and expectant management. Amniotic fluid interleukin-6 and tumor necrosis factor-α were measured by 2 different immunoassays (an automated chemiluminescent enzyme immunoassay and a lateral flow immunoassay). After delivery, patients were divided into a control or a fetal inflammatory response syndrome group according to neonatal interleukin-6 in cord plasma and/or the presence of funisitis. Univariate and multivariate regression analyses were performed and prediction models were developed by calculating receiver operating characteristic curves.

RESULTS

Gestational age at delivery was lower and latency period was longer in the fetal inflammatory response syndrome group compared to the control group. The strongest risk factor for composite adverse neonatal outcome was fetal inflammatory response syndrome (odds ratio, 2.48; confidence interval, 1.40-4.38). The median concentrations of amniotic fluid interleukin-6 and tumor necrosis factor-α in vaginal secretions were significantly higher in the fetal inflammatory response group compared to the control group in both immunoassays (P < .001). The area under the curve of the clinical reference model (including common clinical parameters) was 0.66. Adding interleukin-6 and tumor necrosis factor-α into the model improved the area under the curve to 0.92 (in both assays, interleukin-6 IMMULITE and QuickLine); 0.87 (tumor necrosis factor-α IMMULITE) and 0.94 (tumor necrosis factor-α QuickLine), respectively.

CONCLUSION

The strongest risk factor for worse neonatal outcome (composite neonatal outcome) was fetal inflammatory response syndrome. Amniotic fluid interleukin-6 and tumor necrosis factor-α seem to be good predictors for fetal inflammatory response syndrome and for histologic funisitis and may improve the clinical management of patients with preterm premature rupture of membranes. The noninvasive technique of sampling amniotic fluid from vaginal secretions facilitates daily measurements and bedside assessment of cytokines and is in this respect preferable to invasive amniocentesis.

Maternal serum interleukin-6 in the management of patients with preterm premature rupture of membranes

AIM

To evaluate the clinical usefulness of maternal serum interleukin-6 for the detection of subclinical chorioamnionitis and in the prediction of the latency period in patients with preterm premature rupture of membrane (PPROM).

METHODS

The study group included 60 patients at 24-34 weeks of gestation complaining of PPROM. Laboratory investigations included serial measurements of IL-6, TLC and CRP. Conservative management was carried out till 36 weeks unless delivery was indicated beforehand. The main outcome measures were the latency period and the occurrence of subclinical chorioamnionitis.

RESULTS

The mean gestational age at presentation was 30.9 weeks and 35.2 weeks at delivery. The mean IL-6 level at presentation was 4.7 pg/ml. There was no correlation between IL-6 at presentation and the latency period. In addition, those diagnosed as having subclinical chorioamnionitis by placental histopathology had significantly higher levels of IL-6 at delivery. Taking IL-6 level cutoff point of 8.5 pg/ml, histological chorioamnionitis, RDS and NICU admission were significantly higher above that level while neonatal birth weight, Apgar scores at one and five minutes were significantly lower.

CONCLUSION

Maternal serum IL-6 at the time of PPROM has no correlation to the latency period while IL-6 levels at the time of delivery have significant correlation to the subclinical chorioamnionitis and neonatal outcome measures.

[Evaluation of the interest of procalcitonin in the diagnosis of chorioamnionitis in preterm premature rupture of membranes. An observational and prospective study]

INTRODUCTION

Diagnosis of chorioamnionitis (CA) is difficult because all clinical and biological signs are rarely concordant. According to recent literature, PCT could act as a specific marker of bacterial infection. Our main objective was to assess whether PCT could improve our management of patients with preterm premature rupture of membranes (pPROM), allowing earlier and more specific diagnosis for CA.

METHODS

Patients with pPROM from 24 and 34weeks of amenorrhea were included, from November 2013 to October 2014. PCT was collected twice a week, from pPROM until delivery. Obstetricians were blinded from PCT results, in order not to influence the management of the patients. PCT values were then compared to clinical and other biological diagnostic markers (CRP and white blood cells count [WBC]).

RESULTS

Thirty patients were included, with 11 cases of histological CA and 5 early-onset neonatal sepsis. With a cut-off value of 0.05ng/mL, the sensitivity of PCT to detect histological CA was 54%, the specificity was 79% and the positive and negative predictive value were respectively 60% and 75%. The positive likelihood ratio was 2.57 and the negative likelihood ratio was 0.58. Using PCT values, our medical decision of foetal extraction would have change in 5 cases (in a wrong way in 3 of them).

CONCLUSION

PCT in the diagnostic of CA is not useful in the management of patients.

Cholera in pregnancy: Clinical and immunological aspects

BACKGROUND

The objective of this study was to examine the clinical and immunological features of cholera in pregnancy.

METHODS

Women of reproductive age presenting to the icddr,b Dhaka hospital with cholera, and enrolled as part of a larger cohort study, were tested for pregnancy on admission. We compared initial clinical features and immune responses of pregnant patients with non-pregnant female patients at days 2, 7 and 21 after infection.

RESULTS

Among reproductive age women enrolled between January 2001 and May 2006, 9.7% (14/144) were pregnant. The duration of diarrhoea prior to admission tended to be higher in pregnant compared to non-pregnant patients (p=0.08), but other clinical characteristics did not differ. Antibody responses to cholera toxin B subunit (CtxB), toxin-coregulated pilus A (TcpA), Vibrio cholerae lipopolysaccharide (LPS), and serum vibriocidal antibody responses, were comparable between pregnant and non-pregnant patients. There were no deaths among the pregnant cases or non-pregnant controls, and no adverse foetal outcomes, including stillbirths, during 21 days of follow up of pregnant cases.

CONCLUSIONS

To our knowledge, this is the first report of immune responses in pregnant women with cholera. We found that pregnant woman early in pregnancy has comparable clinical illness and subsequent immune responses compared to non-pregnant women. These findings suggest that the evaluation of safety and immunogenicity of oral cholera vaccines in pregnancy should be an area of future investigations.

Pathogenic bacterial nasopharyngeal colonization and its impact on respiratory diseases in the first year of life: the PATCH Birth Cohort Study

BACKGROUND

For acute respiratory diseases caused by bacteria, colonization in the respiratory tracts is often the first sign, although nasopharynx is the major source of secretions containing pathogens. To understand the pathogenesis of respiratory tract diseases, it is important to analyze the establishment of nasopharyngeal bacterial colonization.

METHODS

Infants with nasopharyngeal swabs were examined at the age of 1, 2, 4, 6 and 12 months for the detection of pathogens, including Streptococcus pneumoniae, Hemophilus influenzae, Moraxella catarrhalis, Streptococcus pyogenes and Staphylococcus aureus. The methods used for detection were bacterial culture and multiplex polymerase chain reaction.

RESULTS

From January 2012 to August 2013, a total of 320 neonates were enrolled, and 120 of them completed the first 12-month study. Staphylococcus aureus was the most common pathogen at all 5 time points while the rates declined; in contrast, the other 4 increased during the first year of life. Of our series, the multiplex polymerase chain reaction detection rates were higher than those of bacterial culture. More than 50% of Staphylococcus aureus was methicillin-resistant, and the trend decreased in the same period. In the analysis of factors associated with the development of infant wheeze, infants with maternal atopy [odds ratio (OR): 3.26; 95% confidence interval (CI): 1.20-8.88; P = 0.02] and pneumococcal colonization (OR: 15.64; 95% CI: 3.25-75.35; P = 0.001) had higher rates of wheeze.

CONCLUSIONS

Bacterial interactions may result in differing pathogen prevalence in the first year of life. In addition, nasopharyngeal pneumococcal colonization may have an effect on the risk of infant wheeze. The result could help clinicians to clarify the relation between bacterial colonization and respiratory illnesses in infancy.

Pregnant women infected with pandemic influenza A(H1N1)pdm09 virus showed differential immune response correlated with disease severity

BACKGROUND

During pregnancy, immunological and hormonal alterations place women at increased risk for influenza-related severe illnesses including hospitalization and death. Although A(H1N1) pdm09 infection resulted in increased disease severity in pregnant women, the precise mechanisms responsible for this risk have yet to be established.

OBJECTIVES

The present study was aimed to investigate the role of host chemokines and cytokine profiles in A(H1N1) pdm09 infection regarding disease severity in pregnant women.

STUDY DESIGN

This retrospective survey examined 41 pregnant women with confirmed A(H1N1) pdm09 infection. Of them, 12 died (D), 29 survived (S), and 17 remained uninfected and served as controls (C). Antiviral response was evaluated for IFN-β expression and gene expression profiles of cytokines (TNF-α, IL-6, IL-12, TGF-β) and chemokines (IL-8, RANTES, MCP-1, IP-10), and the viral Matrix (M1) gene was quantified and normalized using the housekeeping gene product β-actin mRNA.

RESULTS

Higher IL-8 and TNF-α mRNA expression were found in D and S compared with C, while IL-6 showed higher expression in D. Interestingly, these results were associated with a decrease in the anti-inflammatory response of TGF-β mRNA and IFN-β. These alterations would lead to an imbalance in the immune response of those patients.

CONCLUSIONS

Pregnancy-related reductions in IFN-β and TGF-β expression levels and elevated levels of pro-inflammatory cytokines could explain the increased severity of infection and death of pregnant women. These findings may help improve the understanding of the high susceptibility and disease severity to influenza virus infection during pregnancy.

Longitudinal changes in serum proinflammatory markers across pregnancy and postpartum: effects of maternal body mass index

BACKGROUND

The maternal immune system undergoes substantial changes to support healthy pregnancy. Although obesity is a primary driver of inflammation and predictive of perinatal complications, additive effects of pregnancy and obesity on changes in inflammatory processes are not well delineated.

METHODS

This study examined serum proinflammatory markers interleukin(IL)-6, IL-8, tumor necrosis factor (TNF)-α, IL-1β, and C-reactive protein (CRP) during each trimester of pregnancy and 4-6 weeks postpartum among 57 women.

RESULTS

Overall, IL-6 showed an increasing trend across pregnancy and significant increase at postpartum. Similarly, TNF-α increased significantly across gestation, with a further increase at postpartum. Both IL-8 and IL-1β showed a U-shaped curve, decreasing from early to later pregnancy, and increasing at postpartum. Finally, serum CRP decreased significantly across pregnancy, with further decreases at postpartum. Maternal obesity predicted higher IL-6 at each study visit. Obese women showed a trend toward elevated serum CRP during pregnancy, and significantly higher levels at postpartum.

DISCUSSION

The course of pregnancy and postpartum is characterized by significant changes in serum proinflammatory mediators. Obese women show elevations in serum proinflammatory markers relative to normal weight women during pregnancy and postpartum. Further research is needed to determine the extent to which obesity-induced inflammation affects maternal and fetal health.

Changes in maternal blood inflammatory markers as a predictor of chorioamnionitis: a prospective multicenter study

PROBLEM

To evaluate the inflammatory pattern in maternal circulation from women with preterm premature rupture of membranes (PPROM) considering the occurrence of histologically confirmed chorioamnionitis (HCA).

METHOD OF STUDY

A prospective study was conducted in 121 women with PPROM between 24 and 34 + 0 weeks of gestation. Association between white blood cells (WBC) count, plasma CRP, IL-6, MCP-1 and IP-10 levels, and HCA was assessed.

RESULTS

The rate of HCA was 44.7% (54/121). During the 5 days preceding delivery, median CRP, WBC, and IL-6 levels were significantly higher in the HCA than in no-HCA group (P < 0.001). Variations in IL-6, IP-10 levels, during the 24-72 hr before delivery, were predictors of the occurrence of HCA, but the diagnostic accuracy was low [Receiver Operating Characterictic (ROC) curve, area under the curve (AUC) = 0.56].

CONCLUSION

An increase in IL-6, CRP, IP-10 maternal plasma levels was confirmed in PPROM women with HCA. Longitudinal follow-up of these markers did not add valuable information regarding HCA.

Diagnostic and prognostic value of presepsin in preterm deliveries

PROBLEM

To evaluate the association between serum presepsin (soluble CD14 antigen subtype, sCD14-ST) levels soon after the appearance of signs of preterm delivery and preterm delivery within 48 h, before the 34th and 37th gestational weeks and the possible additional value of concurrently evaluated ultrasound vaginal cervicometry with serum presepsin measurement.

METHODOLOGY

A total of 60 females were included. Serum presepsin was measured by a chemiluminescent immunoassay. Sonographic evaluation of cervical length in all females was conducted by transvaginal ultrasound.

RESULTS

Patients who delivered within 48 h after analysis showed significantly higher presepsin concentrations compared to females with later deliveries. Higher presepsin was proven also for deliveries before/after weeks 34 and 37. A combined finding of cervical length shortening below 18 mm and presepsin level increasing above 623.5 pg/mL could point to the significantly high risk of preterm delivery.

CONCLUSION

Elevated maternal serum concentration of sCD14-ST could be an independent and relevant risk factor for preterm delivery.

Self-rated health among pregnant women: associations with objective health indicators, psychological functioning, and serum inflammatory markers

BACKGROUND

Biobehavioral correlates of self-rated health in pregnancy are largely unknown.

PURPOSE

The goals of this study were to examine, in pregnant women, associations of self-rated health with (1) demographics, objective health status, health behaviors, and psychological factors, and (2) serum inflammatory markers.

METHODS

In the second trimester of pregnancy, 101 women provided a blood sample, completed measures of psychosocial stress, health status, and health behaviors, and received a comprehensive periodontal examination.

RESULTS

The following independently predicted poorer self-rated health: (1) greater psychological stress, (2) greater objective health diagnoses, (3) higher body mass index, and (4) past smoking (versus never smoking). Poorer self-rated health was associated with higher serum interleukin-1β (p = 0.02) and marginally higher macrophage migration inhibitory factor (p = 0.06). These relationships were not fully accounted for by behavioral/psychological factors.

CONCLUSIONS

This study provides novel data regarding factors influencing subjective ratings of health and the association of self-rated health with serum inflammatory markers in pregnant women.

Maternal serum cytokines in the prediction of preterm labor and response to tocolytic therapy in preterm labor women

Background:

One of the most important challenges in health care system is prevention of preterm birth. The present study was aimed to investigate the relation between interleukins 6 and 8 (IL-6 and IL-8) with preterm labor and response to tocolytic therapy.

Materials and Methods:

In the year 2012, 75 women with the symptoms of preterm labor (cases) in compare with 75 term women (controls) were randomly selected and evaluated. Baseline data and serum levels of IL-6 and IL-8 (using immunoassay method) recorded. Hence, tocolysis in women in case group was performed with the use of magnesium sulfate and then they were followed until delivery time to assess the response to treatment.

Results:

In case group, 59 women response to tocolytic treatment and delivered at term but 16 of them delivered prematurely. The curve constructed cut-off value for IL-6 was >37.9 (area under the curve [AUC], 0.674; standard error [SE], 0.043; P < 0.0001), and > 9.5 for IL-8 (AUC, 0.773; SE, 0.038; P < 0.0001), indicating a significant relationship with preterm labor. Furthermore, there was a significant relationship between serum IL-6 and IL-8 levels with the response to the treatment in cut-off >45 for IL-6 (AUC, 0.894; SE, 0.042; P < 0.0001) and >171 for IL-8 (AUC, 0.864; SE, 0.059; P < 0.0001).

Conclusion:

In summary, our results suggest that the assessment of maternal serum concentrations of IL-6 and IL-8 can be used as appropriate biomarkers for predicting preterm labor and response to tocolytic therapy in these women. However, further studies needs to be done.

Value of maternal procalcitonin levels for predicting subclinical intra-amniotic infection in preterm premature rupture of membranes

AIM

To determine whether procalcitonin (ProCT) levels can be used to predict subclinical intra-amniotic infection by comparing maternal plasma levels in preterm premature rupture of membranes (PPROM) and premature rupture of membranes (PROM) at term with the levels in healthy pregnant women.

METHODS

The mean plasma ProCT levels of 32 patients with PPROM, 35 patients with PROM at term, 24 healthy women at preterm gestation and 30 healthy women at term were compared. In the PPROM group, the presence or absence of histological chorioamnionitis and neonatal infection were used as a reference to analyze ProCT levels.

RESULTS

The mean ProCT level of patients in the PPROM group was significantly higher than those in the PROM group and healthy controls. Patients in the PPROM group diagnosed with histological chorioamnionitis had significantly higher ProCT levels than those of the remaining patients. At a cut-off of 0.054 ng/mL, the sensitivity and specificity of ProCT to predict histological chorioamnionitis were 92.3% and 68.4%, respectively.

CONCLUSION

ProCT levels were significantly higher in patients with PPROM, and facilitate identification of those who require expectant management.

Maternal positive affect over the course of pregnancy is associated with the length of gestation and reduced risk of preterm delivery

OBJECTIVE

The association between maternal psychological state during pregnancy and birth outcomes is well established. The focus of previous studies has been on the potentially detrimental consequences of maternal stress on pregnancy and birth outcomes, particularly shortened gestation and increased risk of preterm birth. Despite a growing literature linking positive affect with favorable health outcomes this construct has received little attention in the context of pregnancy. Therefore, in the current study, we tested the hypothesis that maternal positive affect during pregnancy is associated with beneficial consequences in terms of increased length of gestation and reduced risk of preterm birth above that of the absence of stress.

METHODS

In 169 pregnant women maternal positive affect and perceived stress were serially assessed at 15.2 ± 0.9 weeks (T1; mean ± SD), 19.7 ± 0.9 weeks (T2) and 30.7 ± 0.7 weeks (T3) gestation. Pregnancy and birth outcomes were abstracted from the medical record.

RESULTS

Higher maternal positive affect and a steeper increase in maternal positive affect over pregnancy were positively associated with length of gestation (p<.05) and reduced risk of preterm delivery (p<.01), whereas maternal perceived stress was not significantly associated with shorter length of gestation (p>.10).

CONCLUSIONS

These findings suggest that maternal positive affect may be beneficial for outcomes related to the length gestation, and that this effect cannot be accounted for by the lower stress levels associated with higher positive affect. Interventions to increase maternal positive affect may be beneficial for fetal development.

Infection and smoking are associated with decreased plasma concentration of the anti-aging protein, α-klotho

OBJECTIVE

The objective of this study was to determine whether maternal plasma concentrations of soluble α-klotho are different between women with microbial invasion of the intra-amniotic cavity (MIAC) and those without MIAC among preterm labor and intact membranes (PTL) or preterm prelabor rupture of membranes (pPROM).

METHODS

A cross-sectional study was conducted to include women in the following groups: i) PTL with MIAC (n=14); ii) PTL without MIAC (n=79); iii) pPROM with MIAC (n=30); and iv) pPROM without MIAC (n=33). MIAC was defined as a positive amniotic fluid culture for microorganisms (aerobic/anaerobic bacteria or genital mycoplasmas). Amniotic fluid samples were obtained within 48 h of maternal blood collection. Plasma concentration of soluble α-klotho was determined by ELISA.

RESULTS

i) The median plasma concentration (pg/mL) of soluble α-klotho was significantly lower in patients with MIAC than in those without MIAC (787.0 vs. 1117.8; P<0.001). ii) Among patients with PTL, those with MIAC had a lower median plasma concentration (pg/mL) of soluble α-klotho than those without MIAC (787.0 vs. 1138.9; P=0.007). iii) Among patients with pPROM, those with MIAC had a lower median plasma concentration (pg/mL) of soluble α-klotho than those without MIAC (766.4 vs. 1001.6; P=0.045). iv) There was no significant difference in the median plasma concentration of soluble α-klotho between PPROM without MIAC and PTL without MIAC (1001.6 pg/mL vs. 1138.9 pg/mL, respectively; P=0.5). v) After adjustment for potential confounders (maternal age, tobacco use, gestational age at venipuncture), soluble α-klotho remained significantly associated with MIAC (P=0.02); and vi) Among patients without MIAC, smoking was significantly associated with a lower median plasma concentration soluble α-klotho than in non-smokers (794.2 pg/mL vs. 1382.0 pg/mL, respectively; P<0.001); however, this difference was not observed in patients with MIAC.

CONCLUSIONS

Intra-amniotic infection occurring at preterm gestations (regardless of membrane status) was associated with a decrease in maternal plasma concentrations of soluble α-klotho. Moreover, among patients without infection, the plasma concentration of α-klotho was lower in smokers.

Targeting interleukin-6 receptor inhibits preterm delivery induced by inflammation

Intrauterine infection is still a common trigger of preterm delivery (PTD) and also a determinant risk factor for the subsequent development of neurodevelopmental abnormalities in neonates. In this study, we examined the expressional pattern of various inflammatory cytokines such as interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) in placentae complicated with severe chorioamnionitis (CAM) and found that IL-6 is mainly expressed in macrophages in villous mesenchyme by immunohistochemical analysis with anti-CD-68 antibody. Using an experimental lipopolysaccharide (LPS)-induced PTD model, the therapeutic potential of targeting this cytokine was investigated. Anti-IL-6 receptor antibody (MR16-1) was delivered 6 h before LPS treatment. Mice in the MR16-1 group had a significantly lower rate of PTD (17%) than in the controls (53%, P = 0.026). As a result, MR16-1 treatment significantly prolonged the gestational period (control; 18.4 ± 1.7d, MR16-1; 19.8 ± 1.5d, P = 0.007) without any apparent adverse events on the mice and their pups. In primary human amniotic epithelial cells, pretreatment with a humanized anti-human IL-6 receptor antibody, tocilizumab, significantly inhibited the production of prostaglandin E2 induced by IL-6. In conclusion, IL-6 was strongly expressed mainly in macrophages in villous mesenchyme in placentae complicated with CAM. Anti-IL-6R antibody significantly decreased the rate of PTD in LPS-induced inflammatory model in mice, and inhibited PGE2 production from human primary amniotic epithelial cells. Targeting IL-6 signaling could be a promising option for the prevention of PTD and needs to be further explored for future clinical application.

Serum proinflammatory cytokine responses to influenza virus vaccine among women during pregnancy versus non-pregnancy

OBJECTIVE

This study aimed to comprehensively describe inflammatory responses to trivalent influenza virus vaccine (TIV) among pregnant women and determine whether responses differ compared to non-pregnancy.

METHODS

Twenty-eight pregnant and 28 non-pregnant women were vaccinated. Serum cytokines were measured at baseline, and 1, 2, and 3 days post-vaccination. Anti-influenza antibody titers were measured at baseline and 1 month post-vaccination.

RESULTS

Overall, following vaccination, tumor necrosis factor (TNF)-α and interleukin(IL)-6 increased significantly, peaking at 1 day post-vaccination (P's < 0.001). Pregnant versus non-pregnant women showed no differences in IL-6, TNF-α, or IL-1β responses. Pregnant women showed no change in IL-8 and increases in migration inhibitory factor (MIF), while non-pregnant showed decreases in both. Pregnancy did not significantly alter antibody responses.

CONCLUSIONS

Inflammatory responses to TIV are mild, transient, and generally similar in pregnant and non-pregnant women. Given the variability evidenced, vaccination may provide a useful model for studying individual differences in inflammatory response propensity.

[Rupture of membranes: pathophysiology, diagnosis, consequences and management]

Rupture of membranes (ROM) depends on mechanical stretch, extracellular matrix components imbalance and increased apoptosis. It occurs in 2 to 3% of all pregnancies before 37 weeks' gestation (WG) and in up to 10% at term. Main consequences are labor induction and risk of maternal-fetal infection. ROM is associated with one third of preterm births and about 20% of perinatal mortality. This review deals with recent knowledge concerning ROM including diagnosis and management. In many cases, ROM is easily identified by clinical examination. In other cases, the use of vaginal pH appears to be less efficient than the use of immunochromatographic strips based on IGFBP-1 or PAMG-1 detection. Before 34WG, conservative management consists in in utero transfer, antibioprophylaxis and corticosteroids. After 37WG, delivery is the most appropriate option. Between 34 and 37WG, recent studies demonstrate that induction of labour does not improve pregnancy outcomes. Therefore, expectant management can be the first option between 34 and 37WG when no active infection is suspected especially in case of unfavourable cervix.

White matter injury following fetal inflammatory response syndrome induced by chorioamnionitis and fetal sepsis: lessons from experimental ovine models

Chorioamnionitis and fetal sepsis can induce a fetal inflammatory response syndrome (FIRS) which is closely related to the development of white matter injury in the fetal brain. Large epidemiological studies support the link between FIRS and fetal brain injury with a clear association between the presence of in utero inflammation and neurodevelopmental complications such as cerebral palsy, autism and cognitive impairments later in life. Translational animal models of chorioamnionitis and fetal sepsis are essential in understanding the underlying pathophysiological mechanisms of fetal brain injury after exposure to intra-uterine inflammation. Concerning this aspect, ovine models have high translational value since neurodevelopment in sheep closely resembles the human situation. In this article, we will review clinical and experimental evidence for the link between FIRS and white matter injury in the fetal brain. With respect to experimental findings, we will particularly focus on the lessons learned from ovine models of chorioamnionitis and fetal sepsis. We also highlight two key players implied in the pathophysiology of white matter injury after in utero exposure to inflammation.

Maternal C-reactive protein at hospital admission is a simple predictor of funisitis in preterm premature rupture of membranes

AIM

To analyze the prognostic value of maternal serum C-reactive protein (CRP) in predicting funisitis in patients with preterm premature rupture of membranes (pPROM).

METHODS

66 patients (gestational age 24-33 weeks) hospitalized 1-12 h after pPROM were enrolled. White blood cell count (WBC), platelet count (PLT) and plasma concentration of CRP were assessed every 3 days. Histological evidence of chorioamnionitis and funisitis was obtained post-partum. Receiver operating characteristic (ROC) curves were employed to evaluate the role of maternal CRP in predicting funisitis.

RESULTS

Funisitis was found in 24 patients (36.3%); 42 patients (63.7%) without funisitis were considered as controls. PLT and WBC at admission and before delivery did not show significant differences and were not statistically different between the two groups. Patients with funisitis had significantly higher CRP levels both at admission to hospital and 24- 48 h before delivery. ROC curve analysis showed that CRP at admission (area under the curve: 0.671, p = 0.021) and before delivery (area under the curve: 0.737, p = 0.001) are predictive of funisitis.

CONCLUSIONS

High maternal serum CRP levels (>20,000 µg/l) in pPROM patients at admission to hospital may be an early marker which indicates, with a good diagnostic performance, the presence of funisitis.

Relationship between maternal serum C-reactive protein, funisitis and early-onset neonatal sepsis

The aim of this study was to determine whether maternal serum C-reactive protein (CRP) is of value in predicting funisitis and early-onset neonatal sepsis (EONS) in women with preterm labor or preterm premature rupture of membranes (PROM). This retrospective cohort study included 306 consecutive women with preterm labor or preterm PROM who delivered preterm singleton neonates (23-35 weeks gestation) within 72 hr of CRP measurement. The CRP level was measured with a highly sensitive immunoassay. The sensitivity, specificity, positive predictive value, and negative predictive value of an elevated serum CRP level (≥ 8 mg/L) were 74.1%, 67.5%, 32.8%, and 92.4% for funisitis, and 67.7%, 63.3%, 17.2%, and 94.6% for EONS, respectively. Logistic regression analysis demonstrated that elevated levels of serum CRP were significantly associated with funisitis and EONS, even after adjusting gestational age. The maternal serum CRP level obtained up to 72 hr before delivery is an independent predictor of funisitis and EONS in women with preterm labor or preterm PROM. A low serum CRP level (< 8 mg/L) has good negative predictive value in excluding funisitis and EONS, and may therefore be used as a non-invasive adjunct to clinical judgment to identify low-risk patients.

A standardized template for clinical studies in preterm birth

BACKGROUND

Preterm birth is a major societal and economic problem accounting for 80 to 90% of neonatal morbidity and mortality worldwide. It is recognized as a complex multifactorial condition comprising several distinct clinical phenotypes with different underlying etiologies. As animal models are expensive and fail to mimic the biology of spontaneous preterm birth in humans, understanding the pathophysiology requires detailed clinical studies. Meta-analyses and clinical translation of data, however, are limited by heterogeneity of study design and size, publication and reporting biases, definition of patient groups, and a lack of standard universal definitions. This article provides a harmonized open-source template for designing clinical studies addressing preterm birth.

METHODS

Recommendations are made for clinical definitions, choice and assignment to preterm birth phenotypes, selection of enriched populations and control pregnancies, and potential confounding factors. In addition, recommendations are made for study design, sample size and power calculations, the minimal data sets needed for any study of preterm birth, and the optimal data set of an ideal study.

RESULTS

Recommended patient phenotypes are infection, uterine overdistension, hemorrhage, stress (either maternal or fetal), and idiopathic. Confounding factors include medical conditions, obesity, antenatal glucocorticoids, multifetal pregnancies, and fetal sex. Guidelines regarding study design, sample size, and clinical data acquisition are provided to serve as a universal template for preterm birth studies.

CONCLUSIONS

Adoption of a harmonized template will allow generation of protocols and studies with a basic degree of compatibility and will allow data to be compared, and samples and data sets to be combined for meaningful meta-analyses.

Psychoneuroimmunology in pregnancy: immune pathways linking stress with maternal health, adverse birth outcomes, and fetal development

It is well-established that psychological stress promotes immune dysregulation in nonpregnant humans and animals. Stress promotes inflammation, impairs antibody responses to vaccination, slows wound healing, and suppresses cell-mediated immune function. Importantly, the immune system changes substantially to support healthy pregnancy, with attenuation of inflammatory responses and impairment of cell-mediated immunity. This adaptation is postulated to protect the fetus from rejection by the maternal immune system. Thus, stress-induced immune dysregulation during pregnancy has unique implications for both maternal and fetal health, particularly preterm birth. However, very limited research has examined stress-immune relationships in pregnancy. The application of psychoneuroimmunology research models to the perinatal period holds great promise for elucidating biological pathways by which stress may affect adverse pregnancy outcomes, maternal health, and fetal development.

Maternal serum interleukin-6 levels predict impending funisitis in preterm premature rupture of membranes after completion of antibiotics

OBJECTIVE

To determine if maternal serum interleukin-6 (IL-6) levels remain predictive of funisitis after completion of antibiotic administration in preterm premature rupture of membranes (PPROM).

METHODS

A secondary analysis of a prospective cohort study. Daily blood samples obtained from PPROM subjects were analyzed for IL-6 by enzyme-linked immunosorbent assay. Subjects (N = 39) delivered >7 days post admission and were divided into those with and without funisitis. Data were analyzed using Mann-Whitney U test.

RESULTS

Maternal serum IL-6 levels obtained 24-48 hours and 48-72 hours before delivery are elevated in PPROM subjects with funisitis compared to those without funisitis (6.3 vs. 2.7 pg/ml, P < 0.03; 6.1 vs. 1.7 pg/ml, P < 0.02). Receiver operator characteristic curve revealed an IL-6 level of 1.98 pg/ml had sensitivity of 86.7%, specificity of 46.7%, positive predictive value of 61.9% and negative predictive value of 77.8%.

CONCLUSION

This data suggests that maternal serum IL-6 levels continue to be predictive of PPROM subjects destined to develop funisitis after completion of antibiotics.

Interleukin-6 as a predictor of subclinical chorioamnionitis in preterm premature rupture of membranes

PROBLEM

One of the major challenges faced by the clinicians in preterm premature rupture of the membranes (PPROM) is to correctly identify when a significant chorioamnionitis is evolving and decide timely delivery of the fetus. Measuring interleukin-6 levels in maternal serum can be useful for the identification of asymptomatic intrauterine infections in subjects with PPROM.

METHOD OF STUDY

A total of 75 pregnant women, of which 45 pregnant women presenting with PPROM between 24 and 34 weeks gestation and 30 healthy pregnant women without PPROM, were included in the study. Serum IL-6 levels were determined by solid-phase sandwich enzyme-linked immunosorbent assay (Diaclone Research, Besancon, France).

RESULTS

The mean serum IL-6 value at admission in the control group was 2.48 ± 2.7 pg/mL and in the study group was 11.86 ± 14.5 pg/mL (P = 0.001). Mean serum IL-6 concentrations at admission in subjects without histological chorioamnionitis were 3.98 ± 3.9 pg/mL and in those who had histological chorioamnionitis were 20.09 ± 16.8 pg/ml (P < 0.001).

CONCLUSION

Maternal serum IL-6 levels were significantly elevated in subjects with PPROM with infectious morbidity as compared to those without infectious morbidity in the present study. There was a significant rise in maternal serum IL-6 levels with increased duration of rupture of membranes and with evidence of histological chorioamnionitis and funisitis in the placenta.

Inflammatory responses to trivalent influenza virus vaccine among pregnant women

OBJECTIVE

In the U.S., seasonal trivalent influenza virus vaccine (TIV) is currently universally recommended for all pregnant women. However, data on the maternal inflammatory response to vaccination is lacking and would better delineate the safety and clinical utility of immunization. In addition, for research purposes, vaccination has been used as a mild immune trigger to examine in vivo inflammatory responses in nonpregnant adults. The utility of such a model in pregnancy is unknown. Given the clinical and empirical justifications, the current study examined the magnitude, time course, and variance in inflammatory responses following seasonal influenza virus vaccination among pregnant women.

METHODS

Women were assessed prior to and at one day (n=15), two days (n=10), or approximately one week (n=21) following TIV. Serum interleukin (IL)-6, tumor necrosis factor (TNF)-α, C-reactive protein (CRP), and macrophage migration inhibitory factor (MIF) were determined by high sensitivity immunoassay.

RESULTS

Significant increases in CRP were seen at one and two days post-vaccination (ps<05). A similar effect was seen for TNF-α, for which an increase at two days post-vaccination approached statistical significance (p=.06). There was considerable variability in magnitude of response; coefficients of variation for change at two days post-vaccination ranged from 122% to 728%, with the greatest variability in IL-6 responses at this timepoint.

CONCLUSIONS

Trivalent influenza virus vaccination elicits a measurable inflammatory response among pregnant women. There is sufficient variability in response for testing associations with clinical outcomes. As adverse perinatal health outcomes including preeclampsia and preterm birth have an inflammatory component, a tendency toward greater inflammatory responding to immune triggers may predict risk of adverse outcomes, providing insight into biological mechanisms underlying risk. The inflammatory response elicited by vaccination is substantially milder and more transient than seen in infectious illness, arguing for the clinical value of vaccination. However, further research is needed to confirm that the mild inflammatory response elicited by vaccination is benign in pregnancy.