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.     

Evidence in support of a role for anti-angiogenic factors in preterm prelabor rupture of membranes

Objective.?Vaginal bleeding, placental abruption, and defective placentation are frequently observed in patients with preterm prelabor rupture of membranes (PROM). Recently, a role of vascular endothelial growth factor (VEGF) and its receptor, VEGF receptor (VEGFR)- 1 has been implicated in the mechanisms of membrane rupture. The purpose of this study was to determine whether the soluble form of VEGFR-1 and -2 concentrations in amniotic fluid (AF) change with preterm PROM, intra-amniotic infection/inflammation (IAI), or parturition.

Study design.?This cross-sectional study included 544 patients in the following groups: (1) midtrimester (MT) (n?=?48); (2) preterm labor (PTL) leading to term delivery (n?=?143); (3) PTL resulting in preterm delivery with (n?=?72) and without IAI (n?=?100); (4) preterm PROM with (n?=?46) and without IAI (n?=?42); (5) term in labor (n?=?48); and (6) term not in labor (n?=?45). The concentrations of sVEGFR-1 and sVEGFR-2 were determined by ELISA. Non-parametric statistics and logistic regression analysis were applied.

Results.?(1) Preterm PROM (with and without IAI) had a lower median AF concentration of sVEGFR-1 than patients with PTL who delivered at term (p?<?0.001 for each comparison); (2) A decrease in AFsVEGFR-1 concentrations per each quartile was associated with PROM after adjusting for confounders (OR 1.8; 95%CI 1.4–2.3); (3) IAI, regardless of the membrane status, was not associated with a change in the median AF concentrations of sVEGFR-1 and sVEGFR-2 (p?>?0.05 for each comparison); and (4) Spontaneous term and PTL did not change the median sVEGFR-1 and sVEGFR-2 concentrations (p?>?0.05 for each comparison).

Conclusion.?(1) This is the first evidence that preterm PROM is associated with a lower AF concentration of sVEGFR-1 than patients with PTL intact membranes. These findings cannot be attributed to gestational age, labor, or IAI; and (2) AF concentrations of sVEGFR-2 did not change with preterm PROM, IAI, or labor at term and preterm.     

Pentraxin 3 in maternal circulation: An association with preterm labor and preterm PROM,but not with intra-amniotic infection/inflammation

Objective.?Pentraxin 3 (PTX3) is an acute-phase protein that has an important role in the regulation of the innate immune response. The aim of this study was to determine if maternal plasma PTX3 concentration changes in the presence of intra-amniotic infection and/or inflammation (IAI) in women with preterm labor (PTL) and intact membranes, as well as those with preterm prelabor rupture of membranes (preterm PROM).

Study design.?This cross-sectional study included women in the following groups: (1) nonpregnant (n?=?40); (2) uncomplicated pregnancies in the first (n?=?22), second (n?=?22) or third trimester (n?=?71, including 50 women at term not in labor); (3) uncomplicated pregnancies at term with spontaneous labor (n?=?49); (4) PTL and intact membranes who delivered at term (n?=?49); (5) PTL without IAI who delivered preterm (n?=?26); (6) PTL with IAI (n?=?65); (7) preterm PROM without IAI (n?=?25); and (8) preterm PROM with IAI (n?=?77). Maternal plasma PTX3 concentrations were determined by ELISA.

Results.?(1) Maternal plasma PTX3 concentrations increased with advancing gestational age (r?=?0.62, p?<?0.001); (2) women at term with spontaneous labor had a higher median plasma PTX3 concentration than those at term not in labor (8.29?ng/ml vs. 5.98?ng/ml, p?=?0.013); (3) patients with an episode of PTL, regardless of the presence or absence of IAI and whether these patients delivered preterm or at term had a higher median plasma PTX3 concentration than normal pregnant women (p?<?0.001 for all comparisons); (4) similarly, patients with preterm PROM, with or without IAI had a higher median plasma PTX3 concentration than normal pregnant women (p?<?0.001 for both comparisons); and (5) among patients with PTL and those with preterm PROM, IAI was not associated with significant changes in the median maternal plasma PTX3 concentrations.

Conclusions.?The maternal plasma PTX3 concentration increases with advancing gestational age and is significantly elevated during labor at term and in the presence of spontaneous preterm labor or preterm PROM. These findings could not be explained by the presence of IAI, suggesting that the increased PTX3 concentration is part of the physiologic or pathologic activation of the pro-inflammatory response in the maternal circulation during the process of labor at term or preterm.     

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.     

Adiponectin in amniotic fluid in normal pregnancy,spontaneous labor at term,and preterm labor: A novel association with intra-amniotic infection/inflammation

Objective.?Adiponectin, an anti-inflammatory and anti-diabetogenic adipokine, has an important regulatory effect on both the innate and adaptive limbs of the immune response. The objective of this study was to determine whether adiponectin is present in amniotic fluid (AF) and if its concentration changes with gestational age, in the presence of labor, and in the presence of intra-amniotic infection (IAI) in patients with spontaneous preterm labor (PTL) and intact membranes.

Study design.?This cross-sectional study included 468 patients in the following groups: (1) women in the mid-trimester of pregnancy (14–18 weeks) who underwent amniocentesis for genetic indications and delivered a normal neonate at term (n?=?52); (2) normal pregnant women at term with (n?=?49) and without (n?=?41) spontaneous labor; (3) patients with an episode of PTL and intact membranes who were classified into: (a) PTL who delivered at term (n?=?149); (b) PTL who delivered preterm (<37 weeks gestation) without IAI (n?=?108); and (c) PTL with IAI (n?=?69). Adiponectin concentration in AF was determined by ELISA.

Results.?(1) The median AF adiponectin concentration at term was significantly higher than in the mid-trimester (35.6?ng/ml, interquartile range [IQR] 26.4–52.7 vs. 29.9?ng/ml, IQR 19.9–35.2; p?=?0.01); (2) among women with PTL and intact membranes, the median AF adiponectin concentration was significantly higher in patients with IAI than in those without IAI who delivered either at term (54.3?ng/ml, 39.0–91.8 vs. 50.1?ng/ml, 33.2–72.8; p?=?0.02) or preterm (47.6?ng/ml, 32.6–74.6; p?=?0.01); and (3) among women at term, there was no significant difference in the median AF adiponectin concentration between those with and without labor (33.7?ng/ml, IQR 21.7–53.9 vs. 35.6?ng/ml, IQR 26.4–52.7; respectively p?=?0.5).

Conclusions.?(1) Adiponectin is a physiologic constituent of AF; and (2) adiponectin concentrations in AF are increased significantly with advancing gestation and in the presence of IAI. Collectively, these findings suggest that adiponectin plays a dynamic role in normal gestation and in the presence of IAI.     

Fragment Bb in amniotic fluid: evidence for complement activation by the alternative pathway in women with intra-amniotic infection/inflammation

Objective.?Fragment Bb is an activator of the alternative pathway of the complement system. Recently, increased first trimester maternal plasma concentrations of this fragment were reported in patients destined to have a spontaneous preterm delivery before 34 weeks of gestation. The aim of this study was to determine whether the amniotic fluid (AF) concentrations of fragment Bb change with gestational age, spontaneous labor (term and preterm) and in the presence of intra-amniotic infection/inflammation (IAI).

Study design.?This cross-sectional study included patients in the following groups: (1) mid-trimester (n = 64); (2) term in spontaneous labor (n = 70); (3) term not in labor (n = 43); (4) spontaneous preterm labor (PTL) who delivered at term (n = 76); (5) PTL without IAI who delivered preterm (n = 73); (6) PTL with IAI (n = 76); (7) preterm prelabor rupture of membranes (PROM) without IAI (n = 71); and (8) preterm PROM with IAI (n = 71). Fragment Bb concentration in AF was determined by an enzyme-linked immunoassay. Non-parametric statistics were used for analyses.

Results.?(1) Fragment Bb was detected in all AF samples (n = 544); (2) The median AF concentration of fragment Bb in patients at term not in labor was significantly higher than that of those in the mid-trimester [2.42 μg/ml, interquartile range (IQR) 1.78–3.22 vs. 1.64 μg/ml, IQR 1.06–3.49; p < 0.001]; (3) Among patients with PTL, those with IAI had a higher median AF fragment Bb concentration than that of woman without IAI, who delivered preterm (4.82 μg/ml, IQR 3.32–6.08 vs. 3.67 μg/ml, IQR 2.35–4.57; p < 0.001) and than that of women with an episode of PTL, who delivered at term (3.21 μg/ml, IQR 2.39–4.16; p < 0.001); (4) Similarly, among patients with preterm PROM, the median AF fragment Bb concentration was higher in individuals with IAI than in those without IAI (4.24 μg/ml, IQR 2.58–5.79 vs. 2.79 μg/ml, IQR 2.09–3.89; p < 0.001). (5) Among patients at term, the median AF fragment Bb concentration did not differ between women with spontaneous labor and those without labor (term in labor: 2.47 μg/ml, IQR 1.86–3.22; p = 0.97).

Conclusions.?(1) Fragment Bb, an activator of the alternative complement pathway, is a physiologic constituent of the AF, and its concentration increases with advancing gestational age; (2) AF concentrations of fragment Bb are higher in pregnancies complicated with IAI; and (3) labor at term is not associated with changes in the AF concentrations of fragment Bb. These findings suggest a role for fragment Bb in the host immune response against IAI.     

The anti-inflammatory limb of the immune response in preterm labor,intra-amniotic infection/inflammation,and spontaneous parturition at term: A role for interleukin-10

Objective. The anti-inflammatory limb of the immune response is crucial for dampening inflammation. Spontaneous parturition at term and preterm labor (PTL) are mediated by inflammation in the cervix, membranes, and myometrium. This study focuses on the changes in the amniotic fluid concentrations of the anti-inflammatory cytokine interleukin (IL)- 10. The objectives of this study were to determine whether there is a relationship between amniotic fluid concentrations of IL-10 and gestational age, parturition (at term and preterm), and intra-amniotic infection/inflammation (IAI).

Study design. A cross-sectional study was conducted including 301 pregnant women in the following groups: (1) mid-trimester of pregnancy who delivered at term (n = 112); (2) mid-trimester who delivered preterm neonates (n = 30); (3) term not in labor without IAI (n = 40); (4) term in labor without IAI (n = 24); (5) term in labor with IAI (n = 20); (6) PTL without IAI who delivered at term (n = 31); (7) PTL without IAI who delivered preterm (n = 30); (8) PTL with IAI who delivered preterm (n = 14). IL-10 concentrations in amniotic fluid were determined by a specific and sensitive immunoassay. Non-parametric statistics were used for analysis.

Results. (1) IL-10 was detectable in amniotic fluid and its median concentration did not change with gestational age from mid-trimester to term. (2) Patients in labor at term had a significantly higher median amniotic fluid IL-10 concentration than that of patients at term not in labor (p = 0.04). (3) Women at term in labor with IAI had a significantly higher median amniotic fluid IL-10 concentration than that of patients at term in labor without IAI (p = 0.02). (4) Women with PTL and IAI who delivered preterm had a significantly higher median amniotic fluid concentration of IL-10 than those without IAI who delivered preterm and than those who delivered at term (p = 0.009 and p < 0.001, respectively). (5) Among patients with preterm labor without IAI, those who delivered preterm had a significantly higher median amniotic fluid IL-10 concentration than those who delivered at term (p = 0.03).

Conclusions. The anti-inflammatory cytokine IL-10 is detectable in the amniotic fluid of normal pregnant women. Spontaneous parturition at term and in preterm gestation is associated with increased amniotic fluid concentrations of IL-10. IAI (preterm and at term) is also associated with increased amniotic fluid concentrations of IL-10. We propose that IL-10 has a role in the regulation of the immune response in vivo by initiating actions that dampen inflammation.     

Maternal plasma visfatin in preterm labor

Objective.?Visfatin, a novel adipokine with diabetogenic and immunoregulatory properties, has been implicated in the pathophysiology of insulin resistance, as well as in various acute and chronic inflammatory disorders. We have previously reported that amniotic fluid concentrations of visfatin are higher in patients with preterm labor (PTL) and intra-amniotic infection than in patients with PTL without infection. The aim of this study was to determine whether spontaneous PTL with intact membranes and intra-amniotic infection/inflammation (IAI) is associated with changes in maternal plasma circulating visfatin concentrations.

Study design.?This cross-sectional study included patients in the following groups: (1) normal pregnant women (n = 123); (2) patients with an episode of PTL and intact membranes without IAI who delivered at term (n = 57); (3) PTL without IAI who delivered preterm (n = 47); and (4) PTL with IAI who delivered preterm (n = 57). Plasma visfatin concentrations were determined by ELISA. Non-parametric statistics were used for analysis.

Results.?(1) PTL with IAI leading to preterm delivery was associated with a higher median maternal plasma concentration of visfatin than normal pregnancy; (2) among patients with PTL, those with IAI had the highest median maternal concentration of visfatin; (3) the changes in maternal plasma visfatin remained significant after adjusting for maternal age, body mass index, gestational age at sampling, and birth weight.

Conclusion.?(1) PTL with IAI is characterized by high maternal circulating visfatin concentrations; (2) these findings suggest that visfatin plays a role in the regulation of the metabolic adaptations to insults resulting in PTL in the context of IAI.     

Amniotic fluid prostaglandin E2 in pregnancies complicated by preterm prelabor rupture of the membranes

Objective: To determine amniotic fluid prostaglandin E2 concentrations in women preterm prelabor rupture of the membranes (PPROM) with respect to microbial invasion of the amniotic cavity (MIAC), intraamniotic inflammation (IAI), microbial-associated IAI, histological chorioamnionitis, and short-term neonatal morbidity.

Methods: One hundred forty-five women with singleton pregnancies were included in this study. Amniotic fluid samples were obtained by transabdominal amniocentesis and were assayed for prostaglandin E2 concentrations by ELISA. IAI was defined as amniotic fluid interleukin-6 >745?pg/mL. Microbial-associated IAI was defined as the presence of both MIAC and IAI.

Result: No differences in prostaglandin E2 concentrations were found between women with and without MIAC (p?=?0.27). Women with IAI (p?=?0.0008) and microbial-associated IAI (p?=?0.01) had higher prostaglandin E2 concentrations than women without these complications. Women with histological chorioamnionitis had higher prostaglandin E2 concentrations only in crude analysis (p?=?0.02), but not after adjustment for gestational age at sampling (p?=?0.10). No associations between amniotic fluid prostaglandin E2 concentrations and the selected conditions of severe neonatal morbidity were found.

Conclusions: The intraamniotic inflammatory response either to infectious or to non-infectious stimulus, but not MIAC per se, seems to be a main factor associated with the elevation of the amniotic fluid PGE2 concentrations in women with PPROM.     

The clinical significance of eosinophils in the amniotic fluid in preterm labor

Objective.?White blood cells are not traditionally considered to be normally present in amniotic fluid. This study was conducted after the observation that a patient with preterm labor and intact membranes had eosinophils as a predominant cell in the amniotic fluid, and had an episode of asthma during the index pregnancy. The goal of this study was to determine whether women presenting with preterm labor with eosinophils in the amniotic fluid had a different outcome than those without eosinophils as the predominant white blood cell in the amniotic cavity.

Methods.?This retrospective case–control study included women who presented with preterm labor and intact membranes between 24 and 34 weeks of gestation. Patients underwent an amniocentesis shortly after admission for the assessment of the microbiologic status of the amniotic cavity and/or fetal lung maturity. Amniotic fluid was cultured for aerobic and anaerobic bacteria as well as genital mycoplasmas. Cytologic studies included amniotic fluid white blood cell count and differential, which was performed on cytocentrifuged specimens. Patients with microbial invasion of the amniotic cavity and/or an amniotic fluid white blood cell count >20 cells/mm³ were excluded from the study. Cases were defined as women in whom the differential contained >20% of eosinophils. Controls were selected among women with an amniotic fluid eosinophil count ≤20% and matched for gestational age at amniocentesis. The analysis was conducted with non-parametric statistics.

Results.?The study population consisted of 10 cases and 50 controls. Gestational age and cervical dilatation at admission were similar in both groups. Cases had a lower gestational age at delivery than controls [34.6 weeks, inter-quartile range (IQR) 32–37.3 weeks vs. 38.0 weeks, IQR 35–40 weeks, respectively; p?=?0.018]. The prevalence of preterm delivery ≤35 weeks was higher among patients who had >20% eosinophils than in the control group [50% (5/10) vs. 18% (9/50), respectively; p?=?0.029]. Similar results were observed for delivery at <37 weeks [cases: 70% (7/10) vs. controls: 36% (18/50); p?=?0.046].

Conclusions.?Women with preterm labor and intact membranes who have a large proportion of eosinophils in the amniotic fluid are at an increased risk for spontaneous preterm delivery. These patients may have had an episode of preterm labor related to a type I hypersensitivity reaction.     

High bisphenol A (BPA) concentration in the maternal,but not fetal,compartment increases the risk of spontaneous preterm delivery

Objective: The objective of this study is to determine if BPA exposure, as measured by maternal plasma (MP) and amniotic fluid (AF) BPA concentrations is associated with an increased risk of spontaneous preterm birth (PTB) and preterm premature rupture of membranes (pPROM).

Methods: In this nested case–control study, MP samples from women in term labor (n?=?30), preterm labor that ended with preterm delivery (n?=?25), or who had pPROM (n?=?30) and amniotic fluid samples from term labor (n=?45), preterm labor (n?=?60), and pPROM (n?=?35) were assayed for BPA by enzyme immunoassay.

Results: BPA was detectible in 100% of MP and AF samples. Women with MP BPA concentrations in the fourth quartile were at increased risk of PTB (cOR?=?4.12, 95% CI?=?1.32–12.87; aOR?=?4.78, 95% CI?=?1.14–20) but not pPROM. High (fourth quartile) AF BPA values also tended to increase the risk of pPROM (cOR?=?2.47, 95% CI?=?0.96–6.37) but results were not statistically significant.

Conclusions: Increased BPA concentration is associated with an increased risk for PTB or pPROM depending on the maternal–fetal compartment(s) affected. High MP plasma BPA concentrations are associated with PTB with intact membranes but high AF BPA concentrations may weakly be associated with pPROM.     

Amniotic fluid calreticulin in pregnancies complicated by the preterm prelabor rupture of membranes

Objective: This study aimed to determine the amniotic fluid calreticulin concentrations in women with the preterm prelabor rupture of membranes (PPROM) based on the microbial invasion of the amniotic cavity (MIAC), intraamniotic inflammation (IAI) and microbial-associated IAI.

Methods: One hundred sixty-eight women with singleton pregnancies were included in this study. Amniotic fluid samples were obtained by transabdominal amniocentesis and were assayed for calreticulin concentrations by ELISA. IAI was defined as an amniotic fluid interleukin-6 concentration?>?745?pg/ml. Microbial-associated IAI was defined as the presence of both MIAC and IAI.

Result: Women with MIAC (with MIAC: median 54.4?ng/ml, versus without MIAC: median 32.6?ng/ml; p?<?0.0001), IAI (with IAI: median 66.8?ng/ml, versus without IAI: median 33.0?ng/ml; p?<?0.0001) and microbial-associated IAI (with microbial-associated IAI: median 82.5?ng/ml, versus without microbial-associated IAI: median 33.7?ng/ml; p?<?0.0001) had higher concentrations of calreticulin than women without these complications. An amniotic fluid calreticulin concentration of 81.4?ng/ml was found to be the best cutoff point for identifying women with microbial-associated IAI.

Conclusions: The presence of microbial-associated IAI is associated with increased amniotic fluid calreticulin concentrations. Calreticulin seems to be a promising marker for the early identification of PPROM complicated by microbial-associated IAI.     

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.     

Amniotic fluid cathepsin-G in pregnancies complicated by the preterm prelabor rupture of membranes

Objective: The aim of this study was to evaluate the amniotic fluid cathepsin-G concentrations in women with preterm prelabor rupture of membranes (PPROM) based on the presence of the microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI).

Methods: A total of 154 women with singleton pregnancies complicated by PPROM were included in this study. Amniotic fluid samples were obtained by transabdominal amniocentesis. Amniotic fluid cathepsin-G concentrations were assessed by ELISA. MIAC was determined using a non-cultivation approach. IAI was defined as an amniotic fluid bedside interleukin-6 concentration?≥?745?pg/mL.

Results: Women with MIAC had higher amniotic fluid cathepsin-G concentrations than women without MIAC (with MIAC: median 82.7?ng/mL, versus without MIAC: median 64.7?ng/mL; p?=?0.0003). Women with IAI had higher amniotic fluid cathepsin-G concentrations than women without this complication (with IAI: median 103.0?ng/mL, versus without IAI: median 66.2?ng/mL; p?p?Conclusions: The presence of either microbial-associated or sterile IAI was associated with increased amniotic fluid cathepsin-G concentrations in pregnancies complicated by PPROM. Amniotic fluid cathepsin-G appears to be a potential marker of IAI.     

Amniotic fluid concentration of surfactant proteins in intra-amniotic infection

Objective. Pulmonary surfactant is a complex molecule of lipids and proteins synthesized and secreted by type II alveolar cells into the alveolar epithelial lining. Both lipid and protein components are essential for lung function in postnatal life. Infection is a well-established cause of preterm delivery, and several inflammatory cytokines play a role in the mechanisms of preterm parturition. An increased concentration of inflammatory cytokines in amniotic fluid or fetal plasma has been linked to the onset of preterm parturition and fetal/neonatal injury, including cerebral palsy and chronic lung disease. Experimental evidence indicates that inflammatory mediators also regulate surfactant protein synthesis, and histologic chorioamnionitis is associated with a decreased incidence of hyaline membrane disease in neonates. This study was conducted to determine if amniotic fluid concentrations of surfactant protein (SP)-A, SP-B, and SP-D change in patients with and without intra-amniotic infection (IAI).

Materials and methods. A case–control study was conducted to determine amniotic fluid concentrations of SP-A, SP-B, SP-D, and total protein in patients who had an amniocentesis performed between 18 and 34 weeks of gestation for the detection of IAI in patients with spontaneous preterm labor with intact membranes (n = 42) and cervical insufficiency prior to the application of cerclage (n = 6). Amniotic fluid samples were selected from a bank of biological specimens and included patients with (n = 16) and without (n = 32) IAI matched for gestational age at amniocentesis. Intra-amniotic infection was defined as a positive amniotic fluid culture for microorganisms. Each group was further subdivided according to a history of corticosteroid administration within 7 days prior to amniocentesis into the following subgroups: (1) patients without IAI who had received antenatal corticosteroids (n = 21), (2) patients with IAI who had received antenatal corticosteroids (n = 9), (3) patients without IAI who had not received antenatal corticosteroids (n = 11), and (4) patients with IAI who had not received antenatal corticosteroids (n = 7). Amniotic fluid was obtained by transabdominal amniocentesis. SP-A, SP-B, and SP-D concentrations in amniotic fluid were determined by enzyme-linked immunosorbent assay (ELISA). Non-parametric statistics were used for analysis.

Results. Women with IAI had a higher median amniotic fluid concentration of SP-B and of SP-B/total protein, but not other SPs, than those without IAI (both p = 0.03). Among patients who had received antenatal corticosteroids, the median amniotic fluid concentration of SP-B and of SP-B/total protein was significantly higher in patients with IAI than in those without IAI (SP-B, IAI: median 148 ng/mL, range 37.3–809 ng/mL vs. without IAI: median 7.2 ng/mL, range 0–1035 ng/mL; p = 0.005 and SP-B/total protein, IAI: median 14.1 ng/mg, range 4.3–237.5 ng/mg vs. without IAI: median 1.45 ng/mg, range 0–79.5 ng/mg; p = 0.003). Among women who had not received antenatal corticosteroids, the median amniotic fluid concentrations of SP-B and of SP-B/total protein were not significantly different between patients with and without IAI (SP-B, IAI: median 4 ng/mL, range 0–31.4 ng/mL vs. without IAI: median 3.4 ng/mL, range 0–37 ng/mL; p = 0.8 and SP-B/total protein, IAI: median 0.55 ng/mg, range 0–6.96 ng/mg vs. without IAI: median 0.59 ng/mg, range 0–3.28 ng/mg; p = 0.9). The median amniotic fluid concentrations of SP-A, SP-A/total protein, SP-D, and SP-D/total protein were not significantly different between patients with and without IAI whether they received antenatal corticosteroids or not (all p > 0.05).

Conclusions. IAI was associated with an increased amniotic fluid concentration of SP-B in patients who received antenatal corticosteroids within 7 days prior to amniocentesis.     

Monocyte chemotactic protein-1 in cervical and amniotic fluid: relationship to microbial invasion of the amniotic cavity, intra-amniotic inflammation, and preterm delivery

OBJECTIVE: The purpose of this study was to evaluate the role of monocyte chemotactic protein-1 in cervical and amniotic fluid in women in preterm labor and with preterm premature rupture of membranes. STUDY DESIGN: Women with singleton pregnancies (相似文献   

Amniotic fluid fetal hemoglobin in normal pregnancies and pregnancies complicated with preterm labor or prelabor rupture of membranes

Objective. Hemoglobin and its catabolic products have been associated with amniotic fluid (AF) discoloration and intra-amniotic infection/inflammation (IAI). However, the origin of AF hemoglobin (maternal or fetal) has not been determined. The aims of this study were to determine if fetal hemoglobin can be detected in AF obtained from normal pregnancies, and whether there is an association between AF fetal hemoglobin concentrations and gestational age, spontaneous labor (term and preterm), preterm prelabor rupture of membranes (PPROM) and IAI.

Study design. This cross-sectional study included pregnant women in the following groups: (1) mid-trimester (n = 60); (2) term not in labor (n = 21); (3) term in labor (n = 47); (4) spontaneous preterm labor with intact membranes (PTL) without IAI who delivered at term (n = 89); (5) PTL without IAI who delivered preterm (n = 74); (6) PTL with IAI (n = 78); (7) PPROM with (n = 48) and (8) without IAI (n = 48). AF fetal hemoglobin concentrations were determined by ELISA. Non-parametric statistics were used for analyses.

Results. (1) Fetal hemoglobin was detected in 80.4% of all AF samples; (2) women at term not in labor had a higher median AF fetal hemoglobin concentration than those at mid-trimester (p = 0.008); (3) labor at term was not associated with a significant difference in the median AF fetal hemoglobin concentration; (4) the median AF fetal hemoglobin concentration was not significantly different among the three PTL groups or between the PPROM groups; (5) women with PTL and IAI had a lower AF fetal hemoglobin percentage of the total hemoglobin than those without IAI who delivered preterm (p = 0.03) or at term (p < 0.001); (6) The median AF fetal hemoglobin concentration was higher in pregnancies complicated with PTL or PPROM than in women at term (p < 0.001 for all comparison).

Conclusions. (1) The concentration of immunoreactive AF fetal hemoglobin increases with gestational age; (2) the median AF fetal hemoglobin concentration is higher in pregnancies complicated with PTL or PPROM than in term pregnancies; (3) among women with PTL or PPROM, the AF fetal hemoglobin concentrations were not associated with IAI; (4) however, women with PTL and IAI had a lower percentage of AF fetal hemoglobin of the total hemoglobin than those without IAI, suggesting different mechanisms of disease.     

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.     

Periodontal disease and intra-amniotic complications in women with preterm prelabor rupture of membranes

Objective: Periodontal disease is frequently suggested as a possible causal factor for preterm delivery. The link between periodontal disease and preterm delivery is a possible translocation of periopathogenic bacteria to the placenta and amniotic fluid as well as a systemic response to this chronic inflammatory disease. However, there is a lack of information on whether there is an association between clinical periodontal status in women with preterm prelabor rupture of membranes (PPROM) and the presence of microbial invasion of the amniotic cavity (MIAC) and intra-amniotic inflammation (IAI). Therefore, the main aim of this study was to evaluate the incidence and severity of periodontal disease in women with PPROM. The secondary aim was to characterize an association between periodontal status and the presence of intra-amniotic PPROM complications (MIAC and/or IAI).

Materials and methods: Seventy-eight women with PPROM at gestational ages between 24?+?0 and 36?+?6 weeks were included in this study. The samples of amniotic fluid were obtained at admission via transabdominal amniocentesis, and amniotic fluid interleukin (IL)-6 concentrations were determined using a point-of-care test. All women had a full-mouth recording to determine the periodontal and oral hygiene status. Probing pocket depth and clinical attachment loss were measured at four sites on each fully erupted tooth.

Results: In total, 45% (35/78) of women with PPROM had periodontal disease. Mild, moderate, and severe periodontal disease was present in 19% (15/78), 19% (15/78), and 6% (5/78) of women, respectively. The presence of MIAC and IAI was found in 28% (22/78) and 26% (20/78) of women, respectively. Periopathogenic bacteria (2?×?Streptococcus intermedius and 1?×?Fusobacterium nucleatum) was found in the amniotic fluid of 4% (3/78) of women. There were no differences in periodontal status between women with MIAC and/or IAI and women without these intra-amniotic complications.

Conclusions: The presence of MIAC and IAI was not related to the periodontal status of women with PPROM.