Differential expression pattern of genes encoding for anti-microbial peptides in the fetal membranes of patients with spontaneous preterm labor and intact membranes and those with preterm prelabor rupture of the membranes

Objective.?Increased amniotic fluid concentrations of anti-microbial peptides, components of the innate immune system, have been reported in patients with preterm labor (PTL) with intact membranes and intra-amniotic infection and/or inflammation (IAI), as well as in patients with preterm prelabor rupture of the membranes (PPROM). This study was designed to confirm these results using a targeted approach, detecting DEFA1, DEFB1, GNLY, and S100A9 gene expression in the choriamniotic membranes in pregnancies complicated with PTL and intact membranes or PPROM, with and without histologic chorioamnionitis.

Study design.?Human fetal membranes were obtained from patients in the following groups: (1) PTL with intact membranes (n?=?15); (2) PTL with intact membranes with histologic chorioamnionitis (n?=?12); (3) PPROM (n?=?17); and (4) PPROM with histologic chorioamnionitis (n?=?21). The mRNA expression of α-defensin-1, β-defensin-1, calgranulin B and granulysin in the fetal membranes was determined by qRT-PCR.

Results.?(1) The expression of α-defensin-1 mRNA in the fetal membranes was higher in patients with PTL and intact membranes with histologic chorioamnionitis, than those without chorioamnionitis (19.4-fold, p?<?0.001); (2) Among patients with histologic chorioamnionitis, patients with PTL and intact membranes had a higher α-defensin-1 mRNA expression than those with PPROM (5.5-fold, p?=?0.003); (3) Histologic chorioamnionitis was associated with a higher calgranulin B mRNA expression in the chorioamniotic membranes of patients with both PTL and intact membranes (7.9-fold, p?=?0.03) and PPROM (7.6-fold, p?<?0.0001); (4) The expression of calgranulin B mRNA in the fetal membranes was higher in patients with PTL and intact membranes without histologic chorioamnionitis than in those with PPROM without histologic chorioamnionitis (2.7-fold, p?=?0.03); (5) There were no differences in the expression of β-defensin-1 and granulysin in the chorioamniotic membranes between the study groups even in the presence of histologic chorioamnioniotis.

Conclusions.?(1) Among patients with histologic chorioamnionitis, the mRNA expression of α-defensin-1 and calgranulin B in the fetal membranes of patients with PTL and intact membranes as well as that of calgranulin B in the fetal membranes of patients with PPROM is higher than in the membranes of those without histologic chorioamnionitis; (2) histologic chorioamnionitis is associated with differences in the pattern of α-defensin-1 mRNA expression in the fetal membranes in patients with PTL and intact membranes and those with PPROM.     

Amniotic fluid heat shock protein 70 concentration in histologic chorioamnionitis,term and preterm parturition

Objective. Heat shock protein (HSP) 70, a conserved member of the stress protein family, is produced in almost all cell types in response to a wide range of stressful stimuli, and its production has a survival value. Evidence suggests that extracellular HSP70 is involved in the activation of the innate and adaptive immune response. Furthermore, increased mRNA expression of HSP70 has been observed in human fetal membranes following endotoxin stimulation. This study was conducted to determine the changes in amniotic fluid HSP70 concentrations during pregnancy, term and preterm parturition, intra-amniotic infection (IAI), and histologic chorioamnionitis.

Study design. A cross-sectional study was conducted in 376 pregnant women in the following groups: (1) women with a normal pregnancy who were classified into the following categories: (a) women in the mid-trimester (14–18 weeks) who underwent amniocentesis for genetic indications and delivered normal infants at term (n=72); (b) women at term not in labor (n = 23); and (c) those at term in labor (n = 48). (2) Women with spontaneous preterm labor and intact membranes who were subdivided into the following categories: (a) preterm labor who delivered at term without IAI (n = 42); (b) preterm labor who delivered preterm without IAI (n = 57); and (c) preterm labor and delivery with IAI (n = 30). (3) Women with preterm prelabor rupture of membranes (PROM) with (n = 50) and without (n = 54) IAI. Among patients with preterm labor with intact membranes and preterm PROM who delivered within 72 hours of amniocentesis, placenta, umbilical cord, and chorioamniotic membranes were collected and assessed for the presence or absence of acute inflammatory lesions in the extraplacental membranes (histologic chorioamnionitis) and/or umbilical cords (funisitis). HSP70 concentrations in amniotic fluid were determined using a sensitive and specific immunoassay. Non-parametric statistics were used for analysis. A p value of <0.05 was considered statistically significant.

Results. Immunoreactive HSP70 was detected in 88% (332/376) of amniotic fluid samples. The median amniotic fluid HSP70 concentration was significantly higher in women at term without labor than in those in the mid-trimester (term no labor: median 34.9 ng/mL, range 0–78.1 ng/mL vs. mid-trimester; median 6.6 ng/mL, range 0–20.8 ng/mL; p<0.001). Among patients with spontaneous preterm labor and preterm PROM, those with IAI had a significantly higher median amniotic fluid HSP70 concentration than those without IAI (preterm labor with IAI: median 82.9 ng/mL, range 0–500 ng/mL vs. preterm labor without IAI: median 41.7 ng/mL, range 0–244 ng/mL; p = 0.001; preterm PROM with IAI: median 86.5 ng/mL, range 0–428 ng/mL vs. preterm PROM without IAI: median 55.9 ng/mL, range 14.9–299.9 ng/mL; p = 0.007). There was no significant difference in the median amniotic fluid HSP70 concentration between patients with preterm labor who delivered preterm without IAI and those who delivered at term (p = 0.6). However, among patients with preterm labor without IAI, there was an inverse relationship between amniotic fluid concentration of HSP70 and the amniocentesis-to-spontaneous delivery interval (Spearman's Rho = ?0.26; p = 0.02). Patients with histologic chorioamnionitis/funisitis had a significantly higher median amniotic fluid HSP70 concentration than those without inflammation (inflammation: median 108.7 ng/mL, range 0–500 ng/mL vs. without inflammation: median 67.9 ng/mL, range 7.1–299.9 ng/mL; p = 0.02). Women at term in labor had a median amniotic fluid concentration of HSP70 significantly higher than those not in labor (term in labor: median 60.7 ng/mL, range 0–359.9 ng/mL vs. term not in labor: median 34.9 ng/mL, range 0–78.1 ng/mL; p = 0.02).

Conclusions. Intra-amniotic infection, histologic chorioamnionitis, and term parturition are associated with elevated amniotic fluid HSP70 concentrations. HSP70 plays a role in the host defense mechanism by activating the innate arm of the immune response in women with intrauterine infection. The mechanisms of preterm and term parturition in humans may involve extracellular HSP70.     

Histological chorioamnionitis in preterm prelabor rupture of the membranes is associated with increased expression of galectin-3 by amniotic epithelium

Purpose: Gal-3, which can regulate immune responses upon infection and inflammation, was not studied so far in intrauterine infection leading to preterm prelabor rupture of the membranes (PPROM), although gal-1 was reported to be implicated in the process. Gal-3 mRNA and protein expression in amnion and its changes during histological chorioamnionitis were studied here.

Materials and methods: Fetal membranes were obtained from women with PPROM with (n?=15) and without histological chorioamnionitis (n?=15) during second and third trimester. Immunohistochemical reactivity was evaluated semiquantitatively and analyzed using t-test. Galectin profile of amniotic epithelia was determined by polymerase chain reaction (PCR) and change assessed in gal-3 in PPROM with (n?=5) or without histological chorioamnionitis (n?=5) by real-time PCR.

Results: Human amniotic epithelium was found to express gal-1, gal-3, gal-7 and gal-8 mRNA. Gal-3 mRNA and protein is increased in fetal membranes and in the amniotic epithelium in patients with chorionamnionitis.

Conclusion: Histological chorioamnionitis is associated with increased gal-3 expression and strong immunoreactivity of the amnion. Gal-3 may participate in the regulation of the inflammatory responses to chorioamniotic infection and/or direct interaction with pathogens.     

A role for CXCL13 (BCA-1) in pregnancy and intra-amniotic infection/inflammation

Objectives. CXCL13 is a potent chemokine, produced by mature and recently recruited macrophages to sites of inflammation, which has antimicrobial and anti-angiogenic properties. The purpose of this study was to: (1) determine whether CXCL13 is present in maternal serum, umbilical cord blood, and amniotic fluid (AF); (2) to determine if AF concentration changes with intra-amniotic infection/inflammation (IAI); and (3) to localize the production of CXCL13 in chorioamniotic membranes and umbilical cord.

Study design. A cross-sectional study on maternal serum was performed including patients in the following groups: (1) non-pregnant women (n = 20), (2) normal pregnant women (n = 49), (3) patients at term not in labor (n = 30), and (4) patients in spontaneous labor at term (n = 29). Umbilical cord blood was collected from term neonates with (n = 30) and without labor (n = 28). Amniotic fluid was obtained from patients in the following groups: (1) midtrimester (n = 65); (2) term not in labor (n = 22); (3) term in labor (n = 47); (4) preterm labor (PTL) with intact membranes leading to term delivery (n = 70); and (5) PTL leading to preterm delivery with IAI (n = 79) and without IAI (n = 60). CXCL13 concentrations were determined by enzyme-linked immunosorbent assay. Chorioamniotic membranes and umbilical cords were examined with immunohistochemistry. Non-parametric statistics were used for analysis.

Results. (1) CXCL13 was present in 100% of serum and cord blood samples, and 99% of AF samples (339/343). (2) Serum CXCL13 concentration was significantly higher in pregnant women when compared to non-pregnant women (median 313.3 pg/mL (interquartile range (IQR) 197.2–646.9) vs. 40.5 pg/mL (IQR 29.5–93.5), respectively; p < 0.001). (3) Serum CXCL13 concentration decreased with advancing gestational age (Spearman's Rho = ?0.424; p < 0.001). (4) There were no significant differences in the median serum CXCL13 concentration between women at term with and without labor (371.6 pg/mL (IQR 194.3–614.3) vs. 235.1 pg/mL (IQR 182.8–354.7), respectively; p = 0.6). (5) The concentration of CXCL13 in AF did not change with gestational age (p = 0.1). (6) Patients with PTL and delivery with IAI had a significantly higher median concentration of CXCL13 than those without IAI (median 513.2 pg/mL (IQR 199.7–2505.5) vs. 137.3 pg/mL (IQR 96.7–209.6), respectively; p < 0.001) and those who delivered at term (133.7 pg/mL (IQR 97.8–174.8); p < 0.001). (7) Spontaneous labor did not result in a change in the median AF concentration of CXCL13 (labor: 86.9 pg/mL (IQR 55.6–152.0) vs. no labor: 77.8 pg/mL (IQR 68.0–98.0); p = 0.8). (8) CXCL13 was immunolocalized to macrophages in fetal membranes and umbilical vein.

Conclusions. (1) We report for the first time the presence of CXCL13 in AF. (2) AF CXCL13 concentrations are dramatically increased in IAI. (3) Unlike other chemokines, AF and serum CXCL13 concentrations did not change with spontaneous parturition.     

Interleukin 18 messenger RNA and proIL-18 protein expression in chorioamniotic membranes from pregnant women with preterm prelabor rupture of membranes

Objective

To quantify the expression of IL-18 mRNA and protein in the chorioamniotic membranes of pregnant women with PPROM and correlate expression with histological chorioamnionitis.

Study design

A case control study that included 42 pregnant women not in labor in the following groups: PPROM (n = 28) and controls with intact membranes submitted to selective cesarean section at term (n = 14). Expression of IL-18 mRNA in chorioamniotic membranes was determined by real-time polymerase chain reaction, and IL-18 protein expression was measured by western blot. Histopathological analyses and immunolocalization of IL-18 by immunohistochemistry were also performed. Analyses were performed using the Mann–Whitney or Fisher's exact tests and the group effect was considered significant if the adjusted p-values were <0.05 and the magnitude of change was greater than 2-fold for mRNA expression.

Results

IL-18 mRNA was present in 100% of samples and no difference in expression was observed between term vs. PPROM membranes (fold-change 0.12; p = 0.88). In the PPROM group, no difference was observed in IL-18 mRNA regarding gestational age (fold-change 0.11; p = 0.42) or the presence of histological chorioamnionitis (fold-change 0.26; p = 0.15). ProIL-18 was present in all samples. IL-18 was immunolocalized to amnion, chorion and decidua cells, with intense immunohistochemical staining at the choriodecidual junction.

Conclusion

Chorioamniotic membranes are sources of IL-18 mRNA and proIL-18, and their expression is unrelated to PPROM or histological chorioamnionitis.     

Inflammatory cytokine mRNA detection by real time PCR in chorioamniotic membranes from pregnant women with preterm premature rupture of membranes

Objective

To quantify the expression of interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor alpha (TNF-α) in chorioamniotic membranes of PPROM pregnant women with chorioamnionits.

Study design

The study included 25 PPROM women in labor, 15 PPROM without labor, and 25 pregnant women in preterm labor (PTL). Chorioamniotic membranes were collected for histopathological analyses and cytokine mRNA expression quantification by real time PCR. Comparisons were performed using the Mann–Whitney, Kruskal–Wallis, Fisher's exact test or z test with significance set at p < 0.05. The software employed was the SigmaStat version 3.1.

Results

During the study PPROM incidence was 4.6% and chorioamnionits was present in 75% of the samples. IL-1β, IL-6, and IL-8 mRNA expression did not statistically differ among study groups. TNF-α mRNA expression was statistically higher in PTL. No difference in the mRNA concentration of the cytokines studied in the presence of chorioamnionitis was observed.

Conclusion

Chorioamniotic membranes are sources of IL-1β, IL-6, IL-8, and TNF-α and their mRNA concentrations in PPROM are not related to the presence of chorioamnionitis.     

Umbilical cord blood levels of cortisol and dehydroepiandrosterone sulfate in preterm prelabor rupture of membrane pregnancies complicated by the presence of histological chorioamnionitis

Objective: The main aim of this study was to determine the levels of cortisol and dehydroepiandrosterone sulfate (DHEA-S) and the cortisol/DHEA-S ratio in the umbilical cord blood according to the presence of histological chorioamnionitis and fetal inflammatory response in pregnancies complicated by prelabor rupture of membranes at fewer than 34 gestational weeks. Methods: Seventy-two women with singleton pregnancies complicated by preterm prelabor rupture of membranes between gestational ages 24+0 and 33+6 weeks were included in the study. The sample of blood was obtained from the umbilical cord after delivery of the newborn. The umbilical cord blood cortisol and DHEA-S levels were evaluated using commercial immunoassay kits. A cortisol/DHEA-S ratio was calculated. Results: The presence of histological chorioamnionitis was not associated with higher median levels of cortisol (32.1 nmol/L vs. 33.0 nmol/L; p = 0.53), DHEA-S (2.6 μmol/L vs. 2.5 μmol/L; p = 0.83), or cortisol/DHEA-S ratio (19.5 vs. 18.7;p = 0.90). Higher median levels of DHEA-S (3.1 μmol/L vs. 2.3 μmol/L; p = 0.03) but not cortisol (91.0 nmol/L vs. 32.0 nmol/L; p = 0.06) or cortisol/DHEA-S ratio (24.5 vs. 18.7; p = 0.46) were observed when fetal inflammatory response was present. Conclusions: The presence of fetal inflammatory response but not the presence of histological chorioamnionitis per se was associated with increased DHEA-S levels in the umbilical cord blood.     

Expression of β defensins 1, 3 and 4 in chorioamniotic membranes of preterm pregnancies complicated by chorioamnionitis

Objective

To quantify the expression of human β-defensins (HBDs) 1, 3 and 4 in chorioamniotic membranes in pregnancies complicated by prematurity associated with histologic chorioamnionitis.

Study design

The study group included 23 fragments of chorioamniotic membranes with histologic chorioamnionitis from women with preterm premature rupture of membranes (PPROM) and preterm labor (PTL) with intact membranes, who had preterm deliveries. As a control group, 30 chorioamniotic membranes without chorioamnionitis at the same gestational age as those in the study group were included. Chorioamniotic membranes were collected for histopathological analyses, and HBD mRNA expression quantification was analyzed by real time PCR. Comparisons were performed using the Mann-Whitney or Kruskal-Wallis tests and all the women were informed and provided written consent.

Results

The expression of HBDs mRNA in the fetal membranes was similar in patients without histologic chorioamnionitis (HBD1: 0.7-fold, HBD3: 0.9-fold, HBD4: 0.3-fold) compared to patients with chorioamnionitis (HBD1: 1.1-fold, HBD3: 0.9-fold, HBD4: 0.4-fold; p > 0.05). Regarding the gestational complications that resulted in premature delivery, PPROM or PTL, the relative quantification of HBD1, HBD3 and HBD4 showed no statistically significant differences in either the absence or presence of chorioamnionitis. Among patients with histologic chorioamnionitis, patients with PPROM (HBD1: 2.7-fold, HBD3: 0.3-fold, HBD4: 0.7-fold) presented similar mRNA expression to those with PTL (HBD1: 0.7-fold, HBD3: 1.2-fold, HBD4: 0.13-fold; p > 0.05).

Conclusions

Chorioamniotic membranes are sources of β defensins 1, 3 and 4; however, considering the sample size and the methodology applied, mRNA concentrations were not related to the presence of histologic chorioamnionitis.     

Funisitis and chorionic vasculitis: the histological counterpart of the fetal inflammatory response syndrome

Objective: To determine whether there is a relationship between the presence of histological signs of inflammation in the extraplacental membranes and umbilical cord and the concentrations of fetal plasma interleukin-6 (IL-6). Methods: The study examined a cohort of patients who were admitted with preterm labor or preterm premature rupture of the membranes (PROM) and who underwent cordocentesis. Inclusion criteria included fetal plasma available for IL-6 determination, histological examination of the umbilical cord and placenta, and delivery within 48 h of the procedure. This last criterion was used to preserve a meaningful temporal relationship between fetal plasma IL-6 and the results of histological examination of the placenta. Fetal plasma IL-6 was determined by a high sensitivity ELISA. Forty-five patients were available for study: 18 patients had preterm labor with intact membranes and 27 had preterm PROM. Results: The incidence of funisitis was 44.4% (20/45): 27.8% (5/18) in patients with preterm labor and intact membranes and 55.6% (15/27) in patients with preterm PROM. The median values of fetal plasma IL-6 in patients with funisitis, chorioamnionitis without funisitis, and non-inflamed membranes were 51.4, 18.4 and 5.2 pg/ml, respectively. After log transformation of the fetal plasma IL-6 concentration, the means differed significantly from each other (ANOVA, p < 0.02). There was no difference in log fetal plasma IL-6 concentration between patients with funisitis and those with chorioamnionitis without funisitis. The difference in mean concentration of log fetal plasma IL-6 between patients with funisitis or chorionic vasculitis and those without inflammation was highly significant (post-hoc test, p = 0.01 and p < 0.01, respectively). Fetuses with fetal plasma IL-6 > 11 pg/ml had a significantly higher rate of histological signs of inflammation in the extraplacental membranes and umbilical cord than those with fetal plasma IL-6 < 11 pg/ml (funisitis: 55.6% (15/27) vs. 27.8% (5/18), p < 0.05; chorionic vasculitis: 55.6% (15/27) vs. 12.5% (2/16), p < 0.01; chorioamnionitis only: 25.9% (7/27) vs. 16.7% (3/18), p < 0.05; no inflammation: 18.5% (5/27) vs. 55.6% (10/18), p < 0.05, respectively). Fetuses with funisitis had significantly higher rates of clinical and histological chorioamnionitis, and neonatal infectious morbidity (proven + suspected sepsis) than fetuses without funisitis (40% (8/20) vs. 8% (2/25), 90% (18/20) vs. 36% (9/25), and 40% (8/20) vs. 4% (1/25), respectively; p < 0.01 for each). Fetuses with chorionic vasculitis had significantly higher rates of clinical and histological chorioamnionitis as well as neonatal infectious morbidity (proven + suspected sepsis) than fetuses without chorionic vasculitis (100% (17/17) vs. 42.3% (11/26), p < 0.01; 82.4% (14/17) vs. 50.0% (13/26), p = 0.05; and 41.2% (7/17) vs. 7.7% (2/26), p = 0.01). Conclusion: Fetal plasma IL-6 concentration is significantly associated with the presence of inflammatory lesions in the extraplacental membranes and umbilical cord. Fetuses with fetal plasma IL-6 > 11 pg/ml had a significantly higher rate of funisitis and/or chorionic vasculitis than fetuses with fetal plasma IL-6 < 11 pg/ml. These findings suggest that funisitis/chorionic vasculitis is the histological manifestation of the fetal inflammatory response syndrome.     

Amniotic fluid soluble human leukocyte antigen-G in term and preterm parturition,and intra-amniotic infection/inflammation

Objective.?Circulating soluble human leukocyte antigen-G (sHLA-G) has been associated with pregnancy complications, and determination of sHLA-G concentrations in amniotic fluid (AF) has been reported in normal pregnancies. Our aim was to determine if the AF concentrations of sHLA-G change with advancing gestation, spontaneous labor at term, and in patients with spontaneous preterm labor (PTL) with intact membranes, as well as in those with preterm prelabor rupture of membranes (PROM), in the presence or absence of intra-amniotic infection/inflammation (IAI).

Study design.?This cross-sectional study included the following groups: (1) mid-trimester (n?=?55); (2) normal pregnancy at term with (n?=?50) and without (n?=?50) labor; (3) spontaneous PTL with intact membranes divided into: (a) PTL who delivered at term (n?=?153); (b) PTL who delivered preterm without IAI (n?=?108); and (c) PTL with IAI (n?=?84); and (4) preterm PROM with (n?=?46) and without (n?=?44) IAI. sHLA-G concentrations were determined by ELISA. Non-parametric statistics were used for analysis.

Results.?(1) Among patients with PTL, the median AF sHLA-G concentration was higher in patients with IAI than in those without IAI or women that delivered at term (p?<?0.001 for both comparisons); (2) Similarly, patients with preterm PROM and IAI had higher median AF sHLA-G concentrations than those without IAI (p?=?0.004); (3) Among patients with PTL and delivery, those with histologic chorioamnionitis and/or funisitis had a higher median AF sHLA-G concentration than those without histologic inflammation (p?<?0.001); and (4) The median AF sHLA-G concentration did not change with advancing gestational age.

Conclusions.?AF sHLA-G concentrations are elevated in preterm parturition associated to IAI as well as in histologic chorioamnionitis. We propose that sHLA-G may participate in the regulation of the host immune response against intra-amniotic infection.     

Soluble ST2 in the fetal inflammatory response syndrome: in vivo evidence of activation of the anti-inflammatory limb of the immune response

Abstract

Objective: Inflammation is a mechanism of host response to infection, which can be harmful when inappropriately modulated. Soluble ST2 (sST2) is a decoy receptor of interleukin (IL)-33, and this complex modulates the balance in the Th1/Th2 immune response. Moreover, sST2 inhibits the production of pro-inflammatory cytokines in cooperation with an anti-inflammatory cytokine, IL-10. The objectives of this study were to: (1) determine whether umbilical cord plasma sST2 concentration differs between preterm neonates with and without funisitis and between those with and without the fetal inflammatory response syndrome (FIRS); and (2) evaluate the relationship between sST2 and IL-10 among neonates with funisitis and/or FIRS.

Methods: Umbilical cord plasma was collected from neonates delivered prematurely due to preterm labor or preterm prelabor rupture of membranes with (n?=?36), and without funisitis (n?=?30). FIRS (umbilical cord IL-6 concentration ≥17.5?pg/mL) was identified in 29 neonates. Plasma sST2 and IL-10 concentrations were determined by enzyme linked immune sorbent assay.

Results: The median umbilical cord plasma sST2 concentration was 6.7-fold higher in neonates with FIRS than in those without FIRS (median 44.6?ng/mL, interquartile range (IQR) 13.8–80.3?ng/mL versus median 6.7?ng/mL, IQR 5.6–20.1?ng/mL; p?<?0.0001). Similarly, the median umbilical cord plasma sST2 concentration was 2.7-fold higher in neonates with funisitis than in those without funisitis (median 19.1?ng/mL; IQR 7.1–75.0?ng/mL versus median 7.2?ng/mL; IQR 5.9–23.1?ng/mL; p?=?0.008). There was a strong positive correlation between sST2 and IL-10 in neonates with funisitis and/or FIRS (Spearman’s Rho?=?0.7, p?<?0.0001).

Conclusion: FIRS and funisitis are associated with an elevation of umbilical cord plasma concentrations of soluble ST2. This protein represents an important mediator of the immune response in neonates diagnosed with FIRS by promoting an anti-inflammatory effect in association with IL-10.     

Parallel detection of lactobacillus and bacterial vaginosis-associated bacterial DNA in the chorioamnion and vagina of pregnant women at term

Background: The majority of early preterm births are associated with intrauterine infections, which are thought to occur when microbes traffic into the uterus from the lower genital tract and seed the placenta. Bacterial vaginosis (BV) is associated with heterogeneous bacterial communities in the vagina and is linked to preterm birth. The extent to which trafficking into the uterus of normal and BV-associated vaginal bacteria occurs is unknown. The study objective was to characterize in parallel the distribution and quantities of bacteria in the vagina, uterus, and placental compartments.

Methods: Pregnant women at term (≥37 weeks) presenting for delivery were recruited prospectively. Swabs were collected in parallel from the vagina, chorioamnion. Choriodecidual swabs were collected if a cesarean section was performed. Samples were analyzed by culture, broad-range 16S rRNA gene PCR, and bacterial species-specific quantitative PCR (qPCR) for DNA from Lactobacillus and a panel of BV-associated bacteria. Results were correlated with placental histopathology.

Results: Of the 23 women enrolled, 15 were delivered by cesarean section (N?=?10 without labor; N?=?5 in labor) and eight were delivered vaginally. BV was diagnosed in two women not in labor. Placental histopathology identified chorioamnionitis or funisitis in six cases [1/10 (10%) not in labor; 5/13 (38%) in labor]. Among non-laboring women, broad-range 16S qPCR detected bacteria in the chorioamnion and the choriodecidua (4/10; 40%). Among laboring women, Lactobacillus species were frequently detected in the chorioamnion by qPCR (4/13; 31%). In one case, mild chorioamnionitis was associated with qPCR detection of similar microbes in the chorioamnion and vagina (e.g. Leptotrichia/Sneathia, Megasphaera), along a quantitative gradient.

Conclusions: Microbial trafficking of lactobacilli and fastidious bacteria into the chorioamniotic membranes and choriodecidua occurs at term in normal pregnancies. In one case, we demonstrated a quantitative gradient between multiple bacterial species in the lower genital tract and placenta. Not all bacterial colonization is associated with placental inflammation and clinical sequelae. Further studies of the role of placental colonization with Lactobacillus in normal pregnancy and fastidious bacteria in chorioamnionitis may improve prevention and treatment approaches for preterm labor.     

Evidence of the involvement of caspase-1 under physiologic and pathologic cellular stress during human pregnancy: A link between the inflammasome and parturition

Objective. Caspase-1 is a component of the NALP3 inflammasome, a cytosolic multiprotein complex that mediates the processing of pro-inflammatory caspases and cytokines. The inflammasome represents the first line of defense against cellular stress and is a crucial component of innate immunity. Caspase-1 is the enzyme responsible for the cleavage and activation of interleukin (IL)-1β, which is a potent pro-inflammatory cytokine, and plays a central role in the mechanisms leading to labor (preterm and term) particularly in the context of intrauterine infection/inflammation. In addition, caspase-1 cleaves IL-18 and IL-33. The objectives of this study were to determine whether there is a relationship between amniotic fluid concentrations of caspase-1 and gestational age, parturition (term and preterm), and intra-amniotic infection/inflammation (IAI).

Study design. A cross-sectional study was conducted including 143 pregnant women in the following groups: (1) mid-trimester of pregnancy (n = 18); (2) term not in labor (n = 25); (3) term in labor (n = 28); (4) preterm labor (PTL) who delivered at term (n = 23); (5) PTL without IAI who delivered preterm (n = 32); (6) PTL with IAI who delivered preterm neonates (n = 17). Caspase-1 concentrations in amniotic fluid were determined by a specific and sensitive immunoassay. Non-parametric statistics were used for analysis.

Results. (1) Caspase-1 was detected in amniotic fluid of women at term, but in none of the mid-trimester samples. (2) Patients in labor at term had a significantly higher median amniotic fluid concentration of caspase-1 than women at term not in labor (term in labor: 10.5 pg/mL, range 0.0–666.0 vs. term not in labor: 5.99 pg/mL, range 0.0–237.4; p < 0.05). (3) Among patients with spontaneous PTL, those with IAI (median 41.4 pg/mL, range 0.0–515.0) had a significantly higher median amniotic fluid caspase-1 concentration than those without IAI who delivered preterm (median 0.0 pg/mL, range 0.0–78.4) and than those who delivered at term (median 0.0 pg/mL, range 0.0–199.5); p < 0.001 for both comparisons.

Conclusions. (1) The presence and concentration of caspase-1 in the amniotic fluid varies as a function of gestational age. (2) Women with spontaneous labor at term had a higher median caspase-1 amniotic fluid concentration than women at term without labor. This suggests that the inflammasome may be activated in spontaneous parturition at term. Since most women with labor do not have intra-amniotic infection, we propose that cellular stress during labor accounts for activation of the inflammasome. (3) Preterm labor associated with infection/inflammation was also associated with a high concentration of caspase-1, suggesting that infection may induce caspase-1 production and activation of the inflammasome. (4) The sequential activation of the inflammasome and caspase-1, leading to interleukin-1β processing and secretion, is a candidate pathway leading to the activation of the common pathway of parturition.     

Alarmin high mobility group box-1 in maternal serum as a potential biomarker of chorioamnionitis-associated preterm birth

Chorioamnionitis is associated with an increased risk of spontaneous preterm birth. The aim of this study was to investigate the serum levels of high mobility group box-1 (HMGB1) in pregnancies with histological chorioamnionitis (HCA)-associated preterm labor (PTL) with intact membranes or preterm premature rupture of membranes (PPROM), and to access the role of serum HMGB1 in HCA and HCA-associated PTL. A total of 190 pregnant women were enrolled in this study: PLT patients with (n?=?28) or without HCA (n?=?36), PPROM patients with (n?=?26) or without HCA (n?=?65), and non-HCA PTL controls (n?=?35). Maternal serum levels of HMGB1 were measured by enzyme-linked immunosorbent assay. Serum HMGB1 levels were significantly higher in PTL or PPROM patients than in control group (p?p?=?0.015). HCA patients were characterized by significantly increased levels of serum HMGB1 when compared with non-HCA patients (p?相似文献   

Cord blood interleukin-6 and neonatal morbidities among preterm infants with PCR-positive ureaplasma urealyticum

Objectives: To evaluate the clinical significance of Ureaplasma urealyticum recovery from umbilical cord blood, using Polymerase Chain Reaction (PCR), and its association with umbilical cord interleukin-6 (IL-6) levels and neonatal morbidity in preterm infants. Methods: Cord blood PCR for Ureaplasma urealyticum, and IL-6 were assessed in relation to neonatal outcomes of 30 preterm deliveries of less than 35 weeks’ gestation. Results: Ureaplasma urealyticum was present in 43.3% of the examined cord blood samples. Positive neonatal Ureaplasma urealyticum was more common in association with premature rupture of membranes, chorioamnionitis, antenatal maternal use of antibiotics, and earlier gestation. Ureaplasma urealyticum was also associated with an early pro-inflammatory immune response (i.e. elevated IL-6 and positive C-reactive protein). Cutoff level of interleukin-6 of 240 pg% predicts the occurrence of respiratory distress syndrome (RDS), in neonates with positive PCR for Ureaplasma urealyticum. Conclusions: Preterm patients with positive cord blood PCR for Ureaplasma urealyticum were more likely to have premature rupture of membrane, antenatal antibiotics, chorioamnionitis, earlier gestation, pro-inflammatory response, and RDS than those with a negative PCR. High IL-6 is more likely associated with RDS in Ureaplasma urealyticum positive neonates.