Objective Preterm parturition is a syndrome caused by multiple etiologies. Although intra-amniotic infection is causally linked with intrauterine inflammation and the onset of preterm labor, other patients have preterm labor in the absence of demonstrable infection. It is now clear that inflammation may be elicited by activation of the Damage-Associated Molecular Patterns (DAMPs), which include pathogen-associated molecular patterns (PAMPs) as well as “alarmins” (endogenous molecules that signal tissue and cellular damage). A prototypic alarmin is high-mobility group box-1 (HMGB1) protein, capable of inducing inflammation and tissue repair when it reaches the extracellular environment. HMGB1 is a late-mediator of sepsis, and blockade of HMGB1 activity reduces mortality in an animal model of endotoxemia, even if administered late during the course of the disorder. The objectives of this study were to: 1) determine whether intra-amniotic infection/inflammation (IAI) is associated with changes in amniotic fluid concentrations of HMGB1; and 2) localize immunoreactivity of HMGB1 in the fetal membranes and umbilical cord of patients with chorioamnionitis. Methods Amniotic fluid samples were collected from the following groups: 1) preterm labor with intact membranes (PTL) with (n=42) and without IAI (n=84); and 2) preterm prelabor rupture of membranes (PROM) with (n=38) and without IAI (n=35). IAI was defined as either a positive amniotic fluid culture or amniotic fluid concentration of interleukin-6 (IL-6) ≥2.6 ng/mL. HMGB1 concentrations in amniotic fluid were determined by ELISA. Immunofluorescence staining for HMGB1 was performed in the fetal membranes and umbilical cord of pregnancies with acute chorioamnionitis. Results Amniotic fluid HMGB1 concentrations were higher in patients with IAI than in those without IAI in both the PTL and preterm PROM groups (PTL IAI: median 3.1 ng/mL vs. without IAI; median 0.98 ng/mL; p<0.001; and preterm PROM with IAI median 7.3 ng/mL vs. without IAI median 2.6 ng/mL; p=0.002); patients with preterm PROM without IAI had a higher median amniotic fluid HMGB1 concentration than those with PTL and intact membranes without IAI (p<0.001); and HMGB1 was immunolocalized to amnion epithelial cells and stromal cells in the Wharton’s jelly (prominent in the nuclei and cytoplasm). Myofibroblasts and macrophages of the chorioamniotic connective tissue layer and infiltrating neutrophils showed diffuse cytoplasmic HMGB1 immunoreactivity. Conclusions Intra-amniotic infection/inflammation is associated with elevated amniotic fluid HMGB1 concentrations regardless of membrane status; preterm PROM was associated with a higher amniotic fluid HMGB1 concentration than PTL with intact membranes, suggesting that rupture of membranes is associated with an elevation of alarmins; immunoreactive HMGB1 was localized to amnion epithelial cells, Wharton’s jelly and cells involved in the innate immune response; and we propose that HMGB1 released from stress or injured cells into amniotic flui...

Objective To determine if maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) and -2 could identify patients at risk for developing preeclampsia (PE) requiring preterm delivery. Study design Patients presenting with the diagnosis ‘rule out PE’ to the obstetrical triage area of our hospital at <37 weeks of gestation (n=87) were included in this study. Delivery outcomes were used to classify patients into 4 groups: I) patients without PE or those with gestational hypertension (GHTN) or chronic hypertension (CHTN) who subsequently developed PE at term (n=19); II): mild PE who delivered at term (n=15); III): mild disease (mild PE, GHTN, CHTN) who subsequently developed severe PE requiring preterm delivery (n=26); and IV): diagnosis of severe PE (n=27). Plasma concentrations of PlGF, sEng, sVEGFR-1 and -2 were determined at the time of presentation by ELISA. Reference ranges for analytes were constructed by quantile regression in our laboratory (n=180; 1,046 samples). Comparisons among groups were performed using multiples of the median (MoM) and parametric statistics after log transformation. Receiver operating characteristic curves, logistic regression and survival analysis were employed for analysis. Results The mean MoM plasma concentration of PlGF/sVEGFR-1, PlGF/sEng, PlGF, sVEGFR-1 and -2, and sEng in Group III was significantly different from Group II (all p<0.05). A plasma concentration of PlGF/sVEGFR-1 ≤ 0.05 MoM or PlGF/sEng ≤ 0.07 MoM had the highest likelihood ratio of a positive test (8.3, 95% CI 2.8–25 and 8.6, 95% CI 2.9–25, respectively), while that of PlGF ≤0.396 MoM had the lowest likelihood ratio of a negative test (0.08, 95% CI 0.03–0.25). The association between low plasma concentrations of PlGF/sVEGFR-1 (≤0.05 MoM) as well as that of PlGF/sEng (≤ 0.07 MoM) and the development of severe PE remained significant after adjusting for gestational age at presentation, average systolic and diastolic blood pressure, and a history of chronic hypertension [adjusted odds ratio (OR) = 27 (95% CI 6.4–109) and adjusted OR 30 (95% CI 6.9–126), respectively]. Among patients who presented <34 weeks gestation (n=59), a plasma concentration of PlGF/sVEGFR-1 <0.033 MoM identified patients who delivered within 2 weeks because of PE with a sensitivity of 93% (25/27) and a specificity of 78% (25/32). This cut-off was associated with a shorter interval-to-delivery due to PE [hazard ratio = 6 (95% CI 2.5–14.6)]. Conclusions Plasma concentrations of angiogenic/anti-angiogenic factors are of prognostic value in the obstetrical triage area. These observations support the value of these biomarkers in the clinical setting for the identification of the patient at risk for disease progression requiring preterm delivery.

Objective High-mobility group box-1 (HMGB1) protein is an alarmin, a normal cell constituent, which is released into the extracellular environment upon cellular stress/damage, and is capable of activating inflammation and tissue repair. The receptor for advanced glycation end products (RAGE) can bind HMGB1. RAGE, in turn, can induce the production of pro-inflammatory cytokines; this may be modulated the soluble truncated forms of RAGE, including soluble RAGE (sRAGE) and endogenous secretory RAGE (esRAGE). The objective of this study was to determine: 1) if clinical chorioamnionitis at term is associated with changes in amniotic fluid concentrations of HMGB1, sRAGE and esRAGE; and 2) if the amniotic fluid concentration of HMGB1 changes with labor or as a function of gestational age. Methods Amniotic fluid samples were collected from the following groups: 1) mid-trimester (MT) (n=45); 2) term with (n=48) and without labor (n=22) without intra-amniotic infection; and 3) term with clinical chorioamnionitis (n=46). Amniotic fluid concentrations of HMGB1, sRAGE and esRAGE concentrations were determined by ELISA. Results 1) the median amniotic fluid HMGB1 concentration was higher in patients at term with clinical chorioamnionitis than that of those without this condition (clinical chorioamnionitis: median 3.8 ng/mL vs. term in labor: median 1.8 ng/mL, p=0.007; and vs. term not in labor median 1.1 ng/mL, p=0.003); 2) in contrast, patients with clinical chorioamnionitis had a lower median sRAGE concentration than those without this condition (clinical chorioamnionitis: median 9.3 ng/mL vs. term in labor: median 18.6 ng/mL, p=0.001; and vs. term not in labor median 28.4 ng/mL, p<0.001); 3) amniotic fluid concentrations of esRAGE did not significantly change in patients with clinical chorioamnionitis at term (clinical chorioamnionitis: median 5.4 ng/mL vs. term in labor: median 6.1 ng/mL, p=0.9; and vs. term not in labor median 9.5 ng/mL, p=0.06); and 4) there was no significant difference in the median AF HMGB1 concentration between women at term in labor and those not in labor (p=0.4) and between women in the mid-trimester and those at term not in labor (mid-trimester: median 1.5 ng/mL; p=0.2). Conclusion An increase in the amniotic fluid HMGB1 concentration and a decrease in sRAGE were observed in clinical chorioamnionitis at term. This finding provides evidence that an alarmin, HMGB1, and one of its receptors, sRAGE, are engaged in the process of clinical chorioamnionitis at term. These changes are quite different from those observed in cases of intra-amniotic infection/inflammation in preterm gestations.

Objective Idiopathic vaginal bleeding, a common complication of pregnancy, increases the risk of SGA neonate, pre-eclampsia and preterm delivery and can be the only clinical manifestation of intra-amniotic infection and/or inflammation (IAI). Placenta previa is thought to be protective against ascending intrauterine infection, yet an excess of histologic chorioamnionitis has been reported in this condition. The aim of this study was to determine the frequency and clinical significance of IAI in women with placenta previa and vaginal bleeding in the absence of preterm labor. Study design A retrospective cohort study including 35 women with placenta previa and vaginal bleeding <37 weeks of gestation who underwent amniocentesis was undertaken. Patients with multiple gestations were excluded. Intra-amniotic infection was defined as a positive culture for microorganisms, and intra-amniotic inflammation as an elevated amniotic fluid interleukin (IL)-6 concentration. IL-6 concentrations were determined by ELISA in 28 amniotic fluid samples available. Non-parametric statistics were used for analysis. Results 1) The prevalence of intra-amniotic infection was 5.7% (2/35), and that of IAI was 17.9% (5/28); 2) the gestational age at delivery was lower in patients with IAI than in those without IAI (29.4 weeks, IQR: 23.1–34.7 vs. 35.4 weeks, IQR: 33.9–36.9; p=0.028); and 3) patients with placenta previa and IAI had a higher rate of delivery within 48 hours (80% (4/5) vs. 19% (4/21); p=0.008) than those without IAI. Conclusions Patients with placenta previa presenting with vaginal bleeding have intra-amniotic infection in 5.7% of the cases, and intra-amniotic infection and/or inflammation in 17.9%. Intra-amniotic infection and/or inflammation in patients with placenta previa and vaginal bleeding is a risk factor for preterm delivery within 48 hours.

OBJECTIVE-The Fetal Inflammatory Response Syndrome (FIRS) is associated with the impending onset of preterm labor/delivery, microbial invasion of the amniotic cavity and increased perinatal morbidity. FIRS has been defined by an elevated fetal plasma interleukin-6 (IL-6), a cytokine with potent effects on the differentiation and proliferation of hematopoietic precursors. The objective of this study was to characterize the hematologic response of fetuses with FIRS.STUDY DESIGN-Fetal blood sampling was performed in patients with preterm prelabor rupture of membranes and preterm labor with intact membranes (n=152). A fetal plasma IL-6 concentration >=11 pg/ml was used to define FIRS. Hemoglobin concentration, platelet count, total white blood cell (WBC) count, differential count and nucleated red blood cell (NRBC) count were obtained. Since blood cell count varies with gestational age, the observed values were corrected for fetal age by calculating a ratio between the observed and expected mean value for gestational age. RESULTS-1)The prevalence of FIRS was 28.9% (44/152); 2) fetuses with FIRS had a higher median corrected WBC and corrected neutrophil count than those without FIRS (WBC median 1.4; range 0.3-5.6 vs. median 1.1; range 0.4-2.9 p=0.001; neutrophils median 3.6; range 0.1-57.5 vs. median 1.8; range 0.2-13.9 p<0.001); 3) neutrophilia (defined as a neutrophil count >95 th centile of gestational age) was significantly more common in fetuses with FIRS than in those without FIRS [71% (30/42) CONCLUSION-The hematological response of the human fetus with FIRS is characterized by significant changes in the total white blood cell and neutrophil counts. The NRBC count in fetuses with FIRS tends to be higher than fetuses without FIRS.