Interleukin-6 and interleukin-1 receptor antagonist in amniotic fluid and cord blood in patients with pre-term, premature rupture of the membranes

Cytokines and parturition: investigating adiponectin, TNF-α, and IL-6 in mother-newborn pairs

OBJECTIVE

Cytokines are reported to be associated with various pregnancy complications and health outcomes of the offspring. However, reference values during pregnancy have not been established, effects of clinical and obstetric factors have not been examined, and interactions between different cytokines have not yet been reported.

METHODS

In this cross-sectional study, we recruited 120 mother-newborn pairs. Maternal venous blood samples (6 mL) were taken on admission to the labor ward; newborn venous blood samples (6 mL) were drawn from the placental part of the umbilical cord (UC). Adiponectin, TNF-α, and IL-6 serum concentrations were measured by commercial immunoassays. Clinical and obstetric variables were analyzed for their association with maternal and UC cytokine concentrations.

RESULTS

Forty-six adiponectin pairs, 55 TNF-α pairs, and 14 IL-6 pairs were available for analysis. Correlation between UC and maternal adiponectin-, IL-6-, and TNF-α levels was low. We found a significant correlation of UC adiponectin with maternal brain-derived neurotrophic factor (BDNF) and maternal adiponectin, and between maternal leptin and maternal TNF-α.

CONCLUSIONS

Clinical and obstetric variables as well as interactions between cytokines may have an impact on serum concentrations of the respective cytokines in maternal and UC blood. Further studies are required to confirm our findings.

Investigating Stress Response during Vaginal Delivery and Elective Cesarean Section through Assessment of Levels of Cortisol, Interleukin 6 (IL-6), Growth Hormone (GH) and Insulin-Like Growth Factor 1 (IGF-1)

Background: How do stress related phenomena during labor differ between vaginal delivery (VD) and elective cesarean section (CS), remains of heightened interest. The purpose of this study is to investigate discrepancies regarding the stress response during VD and CS. Methods: Cortisol, interleukin 6 (IL-6), growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels from parturients’ peripheral blood were evaluated on three time-points, namely during the first stage of labor (TP1), two hours post labor (TP2) and 48 h post labor (TP3). Levels were also evaluated from the umbilical cord blood. A total of 50 women were enrolled in this prospective cohort study, with 24 and 26 subjected to CS and VD, respectively. Results: No statistically significant differences were observed between the two groups at TP1. Only GH levels presented the same pattern during the three time-points among both groups. In the umbilical cord blood, the CS group presented statistically significant higher IGF-1 and GH levels. In the umbilical cord blood, IGF-1 and GH levels were positively correlated, while GH and cortisol levels were negatively correlated. Conclusion: CS is a less stressful procedure than VD and is further associated with less intense inflammation, albeit with a longer inflammatory response period. Labor physiology during CS differs considerably regarding respective observations during VD. This merits extensive investigation in order to decipher these data for optimal clinical practice and guidelines.

HMGB1-RAGE signaling pathway in pPROM

OBJECTIVE

Increased inflammation of the placenta is considered as a risk factor and a promoter of preterm premature rupture of the membranes (pPROM). High-mobility group box 1 (HMGB1) is a recently identified inflammatory cytokine, and HMGB1-RAGE signaling pathway has been associated with many pathophysiological processes. This study aims to reveal the mechanisms of HMGB1-RAGE signaling pathway in pPROM.

MATERIALS AND METHODS

The mRNA levels of relative gene of HMGB1 pathway, HMGB1, RAGE, NF-κBp65, MMP-9 and MMP-2, were analyzed by real-time PCR in placentas collected from 60 normal term women, 60 women with PROM and 60 women with pPROM. Additionally, levels of HMGB1, RAGE, NF-κBp65, MMP-9 and MMP-2 protein were detected in frozen placental specimens by western blot, and the locations of HMGB1, RAGE and NF-κBp65 were evaluated in the well-characterized tissue microarray (TMA) by immunohistochemistry. ELISA was further used to detect HMGB1, RAGE, NF-κBp65, MMP-9 and MMP-2 level in maternal and cord serum.

RESULTS

Compared with normal term and PROM women, we found that (1) The mRNA expressions of HMGB1, RAGE, NF-κBp65, MMP-9 and MMP-2 in HMGB1-RAGE pathway of pPROM placentas were higher. (2) The protein levels of HMGB1, RAGE, NF-κBp65, MMP-9 and MMP-2 in pPROM placentas were higher. (3) HMGB1 and RAGE immunoreactivity in pPROM placenta TMA were increased in the cytoplasm of syncytiotrophoblast (STB), extravillous trophoblast (EVT) and mesenchymal cells, while NF-κBp65 was enhanced in the nucleus of STB and EVT. (4) Maternal serum concentrations of HMGB1, RAGE, NF-κBp65, MMP-9 and MMP-2 in pPROM group were greater. (5) Cord serum concentrations of HMGB1, RAGE, NF-κBp65, MMP-9 and MMP-2 among the 3 groups had no significant differences.

CONCLUSION

HMGB1 nuclear-cytoplasmic translocation in pPROM placenta may lead to the binding of HMGB1 to its receptor RAGE, resulting in provoking NF-κBp65 activity, and then inducing the release of MMP-9 and MMP-2, which all above activities contributed to the process of pPROM. Consequently, HMGB1-RAGE signaling pathway may be involved in the pathogenesis of 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.

Insights into potential pathogenesis mechanisms associated with Campylobacter jejuni-induced abortion in ewes

Background

Campylobacter jejuni is commonly found in the gastrointestinal tract of many food-animals including sheep without causing visible clinical symptoms of disease. However, C. jejuni has been implicated in ovine abortion cases worldwide. Specifically, in the USA, the C. jejuni sheep abortion (SA) clone has been increasingly associated with sheep abortion. In vivo studies in sheep (the natural host) are needed to better characterize the virulence potential and pathogenesis of this clone.

Results

Pregnant ewes intravenously (IV) or orally inoculated with ovine or bovine abortion-associated C. jejuni SA clones exhibited partial or complete uterine prolapse with retained placenta, and abortion or stillbirth, whereas delivery of healthy lambs occurred in pregnant ewes inoculated with C. jejuni 81–176 or in the uninfected group. In sheep inoculated with the SA clone, histopathological lesions including suppurative necrotizing placentitis and/or endometritis coincided with: 1) increased apoptotic death of trophoblasts, 2) increased expression of the host genes (e.g. genes encoding interleukin IL-6 and IL-15) related to cellular necrosis and pro-inflammatory responses in uterus, and 3) decreased expression of the genes encoding GATA binding protein 6, chordin, and insulin-like 3 (INSL3) that account for embryonic development in uterus. Immunohistochemistry revealed localization of bacterial antigens in trophoblasts lining the chorioallantoic membrane of ewes inoculated with the C. jejuni SA clone.

Conclusions

The results showed that C. jejuni SA clones are capable of causing abortion or stillbirth in experimentally infected sheep. Furthermore, down- or up-regulation of specific genes in the uterus of infected pregnant ewes might implicate host genes in facilitating the disease progression. Since the C. jejuni SA strains share genotypic similarities with clones that have been isolated from human clinical cases of gastroenteritis, these strains might represent a potential public health risk.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-014-0274-8) contains supplementary material, which is available to authorized users.

Association of cytokines in hepatitis E with pregnancy outcome

AIMS

The aim of this study was to evaluate tumour necrosis factor-alpha (TNF-α), interleukin (IL)-6, interferon gamma (IFN-γ) and transforming growth factor-beta1 (TGF-β1) in hepatitis E infection during pregnancy and its relation with pregnancy outcome.

METHODS

A total of 272 pregnant and 219 non-pregnant women with hepatitis and 262 age and gestational age matched healthy pregnant women and 208 age matched, healthy non-pregnant women were evaluated on the basis of history, clinical examination, liver function profile. Serological tests of hepatitis A, B, C and E and cytokines using commercially available (ELISA) kits. The patients with hepatitis E were further evaluated for viral load by Real Time PCR. All these were followed till delivery for pregnancy outcome.

RESULTS

HEV viral load in acute viral hepatitis (AVH) and fulminant hepatic failure (FHF) of pregnant women were comparatively higher than non-pregnant women. Significantly higher levels of TNF-α, IL-6, IFN-γ and TGF-β1 were present in HEV infected pregnant women compared to non-pregnant women and controls. TNF-α, IL-6 and IFN-γ had significant positive correlation with viral load, serum bilirubin and prothrombin time in pregnant women. Higher levels of all four cytokines were found in pregnant women with HEV infection having adverse pregnancy outcome compared to that of pregnant women with non-HEV infection and controls.

CONCLUSION

In conclusion, severity of HEV infection and associated adverse pregnancy outcome might be mediated by cytokine in pregnancy.

The comparison of serum interleukin-6 of mothers in vaginal and elective cesarean delivery

BACKGROUND

Interleukin-6 (IL-6) has a major role in hematopoiesis, immune and acute phase response and its serum level seems to be associated with the mode of delivery. The purpose of this study was to compare the level of IL-6 in mothers who delivered via cesarean section and vaginally.

METHODS

This cross-sectional study was done on 40 mothers with vaginal delivery and 40 mothers with elective cesarean delivery in 2012 in Ayatollah Rouhani Teaching Hospital in Babol, northern Iran. Five ml blood samples were taken from each mother. Blood samples were examined by enzyme-immune assay for the determination of IL-6 in both mothers and neonates. Other information, such as the mother's age, newborn sex, gravity, parity, the number of live births of each mother, and the status of infants in terms of being term or pre-term, was recorded.

RESULTS

The mean age of cesarean section and vaginal delivery patients was (29±5.01) yrs and (27.3± 4.93) yrs. The maternal IL-6 concentration in vaginal birth (170.13 ±15.9) was significantly (p<0.05(higher than cesarean section (33±29.94) CONCLUSION: The result shows that serum IL-6 levels in patients with vaginal delivery was higher than those with elective cesarean section delivery. So, vaginal delivery is preferred for all patients except those in whom vaginal delivery is contraindicated.

Interleukin-19 in fetal systemic inflammation

OBJECTIVE

The fetal inflammatory response syndrome (FIRS) is considered the fetal counterpart of the systemic inflammatory response syndrome (SIRS), which can be caused by infection and non-infection-related insults. Although the initial response is mediated by pro-inflammatory signals, the control of this response is achieved by anti-inflammatory mediators which are essential for the successful outcome of the affected individual. Interleukin (IL)-19 is capable of stimulating the production of IL-10, a major anti-inflammatory cytokine, and is a potent inducer of the T-helper 2 (Th2) response. The aim of this study was to determine if there is a change in umbilical cord plasma IL-19 and IL-10 concentrations in preterm neonates with and without acute funisitis, the histologic counterpart of FIRS.

METHODS

A case-control study was conducted including 80 preterm neonates born after spontaneous labor. Neonates were classified according to the presence (n = 40) or absence of funisitis (n = 40), which is the pathologic hallmark of FIRS. Neonates in each group were also matched for gestational age. Umbilical cord plasma IL-19 and IL-10 concentrations were determined by ELISA.

RESULTS

1) The median umbilical cord plasma IL-19 concentration was 2.5-fold higher in neonates with funisitis than in those without funisitis (median 87 pg/mL; range 20.6-412.6 pg/mL vs. median 37 pg/mL; range 0-101.7 pg/mL; p < 0.001); 2) newborns with funisitis had a significantly higher median umbilical cord plasma IL-10 concentration than those without funisitis (median 4 pg/mL; range 0-33.5 pg/mL vs. median 2 pg/mL; range 0-13.8 pg/mL; p < 0.001); and 3) the results were similar when we included only patients with funisitis who met the definition of FIRS by umbilical cord plasma IL-6 concentrations ≥ 17.5 pg/mL (p < 0.001).

CONCLUSION

IL-19 and IL-10 are parts of the immunologic response of FIRS. A subset of fetuses with FIRS had high umbilical cord plasma IL-19 concentrations. In utero exposure to high systemic concentrations of IL-19 may reprogram the immune response.

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.

Male gender promotes an increased inflammatory response to lipopolysaccharide in umbilical vein blood

OBJECTIVES

To establish gender-specific differences in maternal and fetal immune response in healthy human fetuses at term.

METHODS

Forty-five women with elective caesarean sections for uncomplicated singleton pregnancies were recruited for two studies. Using a multiplex biomarker immunoassay system, unstimulated maternal and fetal plasma concentrations of interleukin (IL)-1β, IL-1ra, IL-6, IL-8, macrophage inflammatory protein (MIP)-1α, and tumor necrosis factor (TNF)-α were measured from one study population. Lipopolysaccharide (LPS)-stimulated cytokine response was measured in a second study.

RESULTS

There were no significant gender differences in either maternal or fetal unstimulated plasma cytokine concentrations, but concentrations of the proinflammatory cytokines IL-1β and IL-6 were significantly greater in male fetal LPS-stimulated samples than in female fetal samples.

CONCLUSIONS

Blood of male fetuses mounts a larger pro-inflammatory response to lipopolysaccharide (LPS). This heightened response could be a critical pathway in promoting premature rupture of membranes (PPROM) and may be associated with life long differential gender response to infection.

The antibiotic treatment of PPROM study: systemic maternal and fetal markers and perinatal outcomes

OBJECTIVE

We sought to correlate maternal and cord blood cytokine and intercellular adhesion molecule-1 levels with antibiotic exposure and perinatal outcomes after conservatively managed preterm premature rupture of the membranes.

STUDY DESIGN

Conservatively managed women with preterm premature rupture of the membranes at 24-32 weeks had blood sampling at randomization (n = 222) and delivery (n = 121). Plasma from these, and umbilical cord blood (n = 196), was stored at -70°C. Interleukin (IL)-6, IL-10, granulocyte colony-stimulating factor (G-CSF), tumor necrosis factor-α, and intercellular adhesion molecule-1 levels were assessed for associations with antibiotic treatment, latency, amnionitis, neonatal sepsis, pneumonia, and composite neonatal morbidity.

RESULTS

Cord blood IL-6 and G-CSF were higher than maternal levels. Antibiotic treatment lowered only maternal G-CSF (P = .01). Elevated maternal cytokine levels were associated with delivery within 7 days and with development of chorioamnionitis. All umbilical cord blood markers were increased with amnionitis (P ≤ .01 for each). No maternal marker was associated with neonatal morbidities. Cord G-CSF and IL-6 were increased with neonatal sepsis within 72 hours of birth (P = .004 for both), and with composite neonatal morbidity (P = .001 and .002, respectively). Maternal and umbilical cord cytokine levels demonstrated low predictive values for perinatal outcomes.

CONCLUSION

Umbilical cord blood cytokine values are higher than maternal levels, suggesting significant fetal/placental contribution. Maternal and umbilical cord cytokine levels are not adequately predictive to be used clinically.

Mid-trimester amniotic fluid concentrations of the proinflammatory cytokines IL-6, IL-8, TNF-α, and lipopolysaccharide binding protein in normal pregnancies: a prospective evaluation according to parity, gestational age, and fetal gender

OBJECTIVE

To assess mid-trimester amniotic fluid concentrations of interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, and lipopolysaccharide binding protein (LBP) in pregnancies with normal outcome and correlate them with gestational week (GW), parity, and fetal gender.

METHODS

Cytokine concentrations were measured within a week of amniocentesis during GW 15+0 to 20+6 and correlated with GW at birth, parity, and fetal gender.

RESULTS

After exclusion of women with an adverse pregnancy outcome or those lost to follow-up, 273 consecutive patients were evaluated (median parity: 1; range: 0-5). Ranges for IL-6, IL-8, TNF-α, and LBP were 4.9-2620 pg/mL, 36.2-5843 pg/mL, 8.0-28.2 pg/mL, and 0.06-1.9 μg/mL, respectively. IL-6, IL-8, and LBP values did not respectively differ among time points, but TNF-α values did between the 15(th) and 16(th) and the 15(th) and 18(th) weeks of gestation (P<0.05). No significant correlations between cytokine levels and parity or fetal gender were identified.

CONCLUSIONS

Cytokine concentrations in amniotic fluid during the mid-trimester did not differ with parity or fetal gender. IL-6, IL-8, and LBP levels appeared stable with GW, whereas GW significantly influenced TNF-α concentrations. Further analyses are warranted to establish the role of cytokines in predicting adverse pregnancy outcomes.

Stem cells in the treatment of stroke

Stroke is an often devastating insult resulting in neurological deficit lasting greater than 24 hours. In the United States, stroke is the third leading cause of death. In those who do not succumb, any outcome from total recovery over a period of weeks to months to persistent profound neurological deficits is possible. Present treatment centers on the decision to administer tissue plasminogen activator, subsequent medical stabilization and early intervention with rehabilitation and risk factor management. The advent of stem cell therapy presents an exciting new frontier for research in stroke treatment, with the potential to cause a paradigm shift from symptomatic control and secondary prevention to reconstitution of neural networks and prevention of neuronal cell death after neurologic injury.

Characterization of cytokine production by human term placenta macrophages in vitro

PROBLEM

Macrophages are apparently the only immune cells within placenta villi, yet functions of these cells remain obscure. It has been postulated that placental macrophages accomplish regulatory roles at the fetal-maternal interface by means of wide variety of secreted cytokines. We attempt to analyze the patterns of cytokine production in an isolated population of placental macrophages.

METHOD OF STUDY

Macrophages were obtained from term placentas in the absence of spontaneous labor. The basal and lipopolysaccharide (LPS)-stimulated levels of intracellular cytokines were detected by flow cytometry. The basal cytokine secretion was determined by BD Cytometry Bead Array (BD Biosciences, San Diego, CA, USA).

RESULTS

Intracellular IL-1alpha, IL-1beta, IL-6, and TNFalpha were detected in 31, 27, 4, and 3% CD68+ cells, respectively. Stimulation with LPS increased the proportions of cytokine-producing CD68+ cells to 48, 50, 28, and 49%, respectively. Under basal conditions, levels of released TNFalpha and IL-6, respectively, were 20- and 25-fold higher when compared with IL-1b while IL-10 was secreted in small but detectable amounts. When a secretory activity was estimated for cytokine-producing cells, the secretion rate for TNFalpha and IL-6 overwhelmingly surpassed that for IL-1beta (TNFalpha:IL-6:IL-1beta ratio was 192:145:1).

CONCLUSION

These results suggest functional heterogeneity of the placental macrophage population and contribute to the elucidation of regulatory roles of these cells in gestation.

Changes in amniotic fluid concentration of thrombin-antithrombin III complexes in patients with preterm labor: evidence of an increased thrombin generation

OBJECTIVE

Preterm labor is associated with excessive maternal thrombin generation, as evidenced by increased circulating thrombin-antithrombin (TAT) III complexes concentration. In addition to its hemostatic functions, thrombin has uterotonic properties that may participate in the mechanism leading to preterm birth in cases of intrauterine bleeding. Thrombin also has a proinflammatory role, and inflammation is associated with increased thrombin generation. The aim of this study was to determine whether intra-amniotic infection/inflammation (IAI) is associated with increased amniotic fluid (AF) thrombin generation in women with preterm and term deliveries.

STUDY DESIGN

This cross-sectional study included the following groups: (1) mid-trimester (n = 74); (2) term not in labor (n = 39); (3) term in labor (n = 25); (4) term in labor with IAI (n = 22); (5) spontaneous preterm labor (PTL) who delivered at term (n = 62); (6) PTL without IAI who delivered preterm (n = 59); (7) PTL with IAI (n = 71). The AF TAT III complexes concentration was measured by enzyme linked immunosorbent assay (ELISA). Non-parametric statistics were used for analysis.

RESULTS

(1) TAT III complexes were identified in all AF samples; (2) patients with PTL who delivered preterm, with and without IAI, had a higher median AF TAT III complexes concentration than those with an episode of PTL who delivered at term (p < 0.001, p = 0.03, respectively); (3) among patients with PTL without IAI, elevated AF TAT III complexes concentration were independently associated with a shorter amniocentesis-to-delivery interval (hazard ratio, 1.5; 95% CI, 1.07-2.1); (4) among patients at term, those with IAI had a higher median AF TAT III complexes concentration than those without IAI, whether in labor or not in labor (p = 0.02); (5) there was no significant difference between the median AF TAT III complexes concentration of patients at term with and without labor; (6) patients who had a mid-trimester amniocentesis had a lower median AF TAT III complexes concentration than that of patients at term not in labor (p < 0.001).

CONCLUSIONS

We present herein a distinct difference in the pattern of intra-amniotic thrombin generation between term and preterm parturition. PTL leading to preterm delivery is associated with an increased intra-amniotic thrombin generation regardless of the presence of IAI. In contrast, term delivery is associated with an increased intra-amniotic thrombin generation only in patients with IAI.

Cytokine gene polymorphisms in recurrent spontaneous abortions: a comprehensive review

PROBLEM

Cytokine gene polymorphism studies in women with recurrent spontaneous abortion (RSA) are reviewed to provide comprehensive understanding and a direction for the future investigation.

METHOD OF STUDY

A search of PubMed was made to identify the published data between 2001 and 2007 regarding RSA and cytokine gene polymorphisms.

RESULTS

Either allele and/or genotype frequencies of the following polymorphisms were reported to be significantly different between women with RSA and controls: IFN-gamma +874A-->T, TA (P = 0.01), AA (P = 0.04); IL-6, -634C-->G CG/GG (P = 0.026); IL-10, -592C-->A CC (P = 0.016); IL-1B -511C (P = 0.035), -31T (P = 0.029); IL-1RA, IL1RN*2 (P = 0.002), and IL1RN*3 (P = 0.002). None of these studies was repeatedly reported by others to be significantly different. Among these, four cytokine polymorphisms (IFN-gamma, +874A-->T; IL-1B -511C; IL-1RA, IL1RN*2, IL1RN*3) were refuted by others and rest of them were studied once.

CONCLUSION

Multiple cytokine polymorphisms were reported to be associated with RSA. However, a majority of studies were not confirmed by other investigators or refuted by others. Inconsistent study results might be related to: (i) the production of these cytokines is partly under genetic controls and other factors affect cytokine levels; (ii) ethnic background, environmental factors, and selection criteria for study populations are different and (iii) the possibilities exist that multiple cytokine gene polymorphisms or other genes in linkage disequilibrium may play a role in RSA.

Differences in amniotic fluid and maternal serum cytokine levels in early midtrimester women without evidence of infection

The amniotic fluid cytokine profile has been shown to be indicative of various disease states, and changes may be associated with preterm labor or infection. Anti-inflammatory cytokine profiles may be essential for successful normal pregnancy. However, there are currently few normative data on the concentration of cytokines in amniotic fluids during pregnancy. The aim of this study was to provide new amniotic fluid cytokine data for future comparative studies in disease states, notably in utero viral infections, and to compare these with maternal serum levels. Amniotic fluid was obtained from 100 pregnant women undergoing elective amniocentesis at the Royal Hospital for Women, Randwick. Concentrations of 27 cytokines were simultaneously measured in amniotic fluid and a subset of matching maternal sera (n=33) using a multiplex bead-based immunoassay system (Bio-Plex, Bio-Rad). To exclude infection, nested multiplex PCR targeting 17 known congenital infectious agents were performed on all amniotic fluid and maternal serum samples, and serological testing was also performed against some of these agents. Maternal serum concentration was positively correlated with amniotic fluid levels for MIP-1beta (r=0.39, P=0.027). IL-1ra was positively correlated to maternal age (r=0.210, P=0.036), and mean IL-5 levels were significantly higher in amniotic fluids from pregnancies with male fetuses than those with female fetuses (P=0.036). Normal amniotic fluid concentrations for five cytokines (IL-6, IL-8, IP-10, MCP-1, IL-1ra) were found to be significantly elevated over maternal serum concentrations in matched pairs (P<0.05). Concentrations of 12 cytokines (eotaxin, IFN-gamma, IL-9, IL-12, IL-15, IL-17, MIP-1alpha, MIP-1beta, RANTES, TNF-alpha, VEGF, PDGF bb) were significantly elevated in maternal serum compared to paired amniotic fluid at midtrimester (P<0.05). Amniotic fluid may be more representative of the fetal cytokine profile than cytokine analysis on antenatal sera as it represents predominantly fetal urinary and respiratory secretions. This study provides new normative data for multiple cytokine levels in amniotic fluid and maternal sera at 14-16 weeks gestation, and is a valuable tool for future diagnostic and comparative studies.

Neuroimaging of neonatal encephalopathies

Neonatal brain disorders consist of a wide chapter including brain malformations, hypoxic-ischemic encephalopathy (HIE), intracranial infections, perinatal trauma and metabolic encephalopathy. We will focus here on HIE, intracranial infections (especially materno-fetal infection with or without prolonged and/or premature rupture of membranes) and metabolic encephalopathy, those three conditions being the most frequent so far in our experience. Neonatal stroke is also analyzed. Moreover minor perinatal events might be superimposed on an already damaged (infective, edematous, metabolically abnormal or maldeveloped) brain, highlighting the main role and potential benefits of neuroimaging during the neonatal period. The different methods of brain imaging are thus reported with their advantages and disadvantages.

Elevated circulating IL-1beta and TNF-alpha, and unaltered IL-6 in first-trimester pregnancies complicated by threatened abortion with an adverse outcome

The purpose of the present study was to examine the profile of selected proinflammatory cytokines in maternal serum of first-trimester pregnancies complicated by threatened abortion (TACP) and its relevance to obstetric outcome. Serum levels of Th1-type cytokines interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-alpha), and Th2-type cytokine interleukin 6 (IL-6) were measured, by ELISA, in 22 women with TACP and adverse outcome at admission (group A) and compared with the corresponding levels of 31 gestational age-matched women with TACP and successful outcome at admission (group B1) and discharge (group B2) and 22 gestational age-matched women with first-trimester uncomplicated pregnancy (group C) who served as controls. Mann-Whitney U or Wilcoxon test was applied as appropriate to compare differences between groups. IL-1β and TNF-alpha were detected with significantly higher levels in group A, compared to all other groups. On the contrary, IL-6 levels were detected with no significant difference among all the other groups studied. It is concluded that in first-trimester TACP with adverse outcome, a distinct immune response, as reflected by elevated maternal IL-1β, TNF-alpha, and unaltered IL-6 levels, is relevant to a negative obstetric outcome.

Maternal Serum Cytokines in Preterm Premature Rupture of Membranes

OBJECTIVE

To estimate whether maternal serum interleukin (IL)-6 or granulocyte colony-stimulating factor (G-CSF) obtained daily are elevated in women with preterm premature rupture of membranes who develop funisitis.

METHODS

Daily blood samples were obtained from women with preterm premature rupture of membranes and analyzed for IL-6 and G-CSF by enzyme-linked immunosorbent assay. Funisitis was determined by placental examination. Observations were stratified based on the presence or absence of funisitis and analyzed. Proportional hazards models were used to evaluate time-to-delivery on the basis of diagnostic IL-6 and G-CSF levels, determined by receiver operating characteristic curve analysis.

RESULTS

Of the 107 patients available for analysis, 54 (50%) had evidence of funisitis after delivery. Patients with funisitis were more likely to deliver at an earlier gestational age (28.5 weeks compared with 31.5 weeks, P<.001) and have Medicaid insurance (57% compared with 39%, P=.04). Serum IL-6 and G-CSF were elevated 24 to 48 hours before delivery in women with preterm premature rupture of membranes with funisitis compared with those without funisitis (IL-6, 7.5 compared with 2.8 pg/mL, P<.001; G-CSF, 121.7 compared with 56.9 pg/mL, P=.002). Using values identified by the receiver operating characteristic curve, elevated serum IL-6 in the interval 24-72 hours before delivery was significantly associated with funisitis (P<.03), even after controlling for gestational age and insurance status.

CONCLUSION

Maternal serum IL-6 and G-CSF appear to be biomarkers in the identification of women with preterm premature rupture of membranes likely to develop funisitis.

LEVEL OF EVIDENCE

II.

Use of topical human amniotic fluid in the treatment of acute ocular alkali injuries in mice

PURPOSE

To evaluate the efficacy of topical human amniotic fluid (HAF) in the treatment of ocular acute alkali burns in mice.

DESIGN

Experimental study.

METHODS

A chemical burn with 2 microl of sodium hydroxide 0.15 mol/l was created in one eye of 30 mice. The animals were divided into gender- and age-matched groups according to the topical treatment that was administered: group 1 was treated with preterm HAF (n = 10 mice); group 2 was treated with term HAF (n = 10 mice), and group 3 was treated with saline solution (n = 10 mice). Treatment consisted of one drop that was applied to the burned eye five times per day (week one), and three times per day (week two). The epithelial defect was photographed and measured on days two and four. Ocular burn damage was assessed at days two, seven, and 14 after a pre-established classification. On day 14, both eyes of each mouse were enucleated and assessed histopathologically.

RESULTS

Median epithelial defect (interquartile range [IQR], 25th, 75th percentile) at day four was 9.93% (IQR, 8.57, 11.27) for group 1, 7.30% (IQR, 5.96, 8.97) for group 2, and 18.92% (IQR, 11.71, 27.64) for group 3 (P < .0076). The overall change (difference in slope) in ocular burn score between days 2 and 14 was -0.127 (P = .009) in group 1 vs 3, -0.134 (P = .012) in group 2 vs 3, and 0.007 (P = .88) in group 1 vs 2. On histologic examination saline solution-treated corneas had more inflammatory cells and blood vessels than HAF-treated corneas.

CONCLUSION

Topical preterm/term HAF was an effective topical therapy for limiting the damage after acute alkali burns of the eye in this animal model.

Human spontaneous labor without histologic chorioamnionitis is characterized by an acute inflammation gene expression signature

OBJECTIVE

The purpose of this study was to identify which biological processes may be involved in normal labor.

STUDY DESIGN

Transcriptional profiles for chorioamniotic membranes (n = 24) and blood (n = 20) were generated from patients at term with no labor (TNL) and in labor (TIL).

RESULTS

Expression of 197 transcripts (P < or = .02) differentiated TIL and TNL chorioamniotic membrane samples. Gene Ontology analysis indicated that TIL samples had increased expression of multiple chemokines and transcripts associated with neutrophil and monocyte recruitment. Microarray results were verified using quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) with independent samples. Transcriptional profiles from blood RNA revealed no Gene Ontology category enrichment of discriminant probe sets.

CONCLUSION

Labor induces gene expression changes consistent with localized inflammation, despite the absence of histologically detectable inflammation.

Mechanisms underlying "functional" progesterone withdrawal at parturition

Progesterone is a major factor maintaining uterine quiescence throughout pregnancy. In most species, peripheral progesterone levels decline before initiation of labor, and treatments that inhibit progesterone synthesis or action cause termination of pregnancy and/or premature deliveries. These findings suggest that progesterone withdrawal is required for activation of myometrial contractions. However, in humans, circulating progesterone levels remain elevated until birth, which leads to the notion that a "functional" progesterone withdrawal occurs before parturition. The apparent loss of progesterone sensitivity at term could be a consequence of several different mechanisms including: (1) the catabolism of progesterone in the uterus into inactive compounds; (2) alterations in progesterone receptor (PR) isoform ratios; (3) changes in cofactor protein levels affecting PR transactivation; and (4) inflammation-induced trans-repression of PR by nuclear factor kappaB. All of these mechanisms are potentially capable of decreasing uterine progesterone responsiveness at term, thus enabling the expression of pathways that originally were blocked by progesterone in early pregnancy. However, the specific uterine genes whose transcription is directly controlled by PR, and thus affected by "functional" progesterone withdrawal, remain to be identified.

Tumor necrosis factor-alpha suppresses the expression of steroid receptor coactivator-1 and -2: a possible mechanism contributing to changes in steroid hormone responsiveness

Inflammation is associated in some tissues with diminished responsiveness to steroid hormone action. We hypothesized that proinflammatory cytokines alter steroid hormone sensitivity, in part, by reducing levels of key nuclear receptor coactivators. Treatment of cultured human uterine smooth muscle cells (UtSMC) with TNF-alpha significantly reduced mRNA for the coactivators, SRC-1 (42%, P<0.01) and 2 (47%, P<0.03), and diminished the respective protein levels, but did not significantly alter the mRNAs encoding SRC-3, CBP and the corepressors, NCoR and SMRT; or progesterone receptor protein levels. To assess TNF-alpha effects on steroid hormone-mediated transcriptional activity, UtSMC were transfected with progesterone receptor B (PR-B) and a model PRE2-luciferase reporter construct. Transfected UtSMC were treated with progesterone alone or in the presence of TNF-alpha, and assayed for luciferase activity. TNF-alpha (10 ng/ml) diminished progesterone-stimulated PR-B-mediated transactivation by approximately 60% (P<0.02). The TNF-alpha-dependent decrease in PRE-luciferase activity was fully prevented by cotransfection with SRC-2, and partially prevented with exogenous SRC-1. In conclusion, TNF-alpha impairs progesterone-stimulated PR-B-mediated transactivation, and these effects appear to be due, in part, to reduced expression of SRC-1 and -2, which is a novel mechanism by which inflammation can functionally block steroid hormone action.

Cervical Lactobacillus and leukocyte infiltration in preterm premature rupture of membranes

OBJECTIVES

To evaluate the possible association between microorganisms present in the cervical secretions and amniotic fluid of pregnant women with preterm premature rupture of membranes (PPROM), and histologic chorioamnionitis.

METHODS

Thirty-seven pregnant women with PPROM and 21 healthy pregnant women were studied. Secretions from the cervical canal and amniotic fluid were collected to isolate microorganisms present in the genital tract. Cervical smears were Gram stained and evaluated microscopically. At delivery, chorioamniotic membranes were collected for histopathologic analysis.

RESULTS

Microscopic examination of the cervical secretion smears obtained from the PPROM group showed a low rate of Lactobacillus species, large numbers of leukocytes, and a wide diversity of microorganisms compared with the control group. The PPROM group presented an 80% rate of chorioamnionitis. Staphylococcus aureus isolation in cervical secretion was associated with intense inflammatory infiltrate in the membranes and might play a role in the pathogenesis of PPROM.

CONCLUSIONS

The low colonization of cervical flora by Lactobacillus species associated with an intense leukocyte infiltrate detected in Gram-stained cervical smears can be considered a rapid method of detecting chorioamnionitis in pregnant women with PPROM.

Maternal serum and amniotic fluid cytokines in patients with preterm premature rupture of membranes with and without intrauterine infection

OBJECTIVES

To evaluate the role of interleukins (IL-1, IL-6), tumor necrosis factor alpha (TNFalpha) and for the first time interferon gamma (IFNgamma) and epidermal growth factor (EGF) in the pathogenesis of premature rupture of membranes (PROM) with and without confirmed intrauterine infection.

METHODS

Amniotic fluid was retrieved by transabdominal amniocentesis from 30 patients with PROM and 20 normal pregnant women with intact membranes of matched gestational age. Microbial state of amniotic cavity included culture for aerobic and anaerobic bacteria, mycoplasmas and ureaplasma whether or not clinical signs of chorioamnionitis were present. Maternal serum and amniotic fluid IL-1, IL-6, TNFalpha and IFNgamma concentrations were determined by the corresponding immunoradiometric assay, whereas EGF concentration was determined by a specific radioimmunoassay.

RESULTS

Nearly all cases of PROM with infection revealed elevated amniotic fluid cytokines (IL-1beta, IL-6, TNFalpha, IFNgamma, EGF) whereas half of them revealed elevated serum cytokines. In cases of PROM without confirmed infection, there were no significant changes of maternal serum cytokines, whereas two-thirds of them revealed elevated amniotic fluid cytokines.

CONCLUSIONS

The rise of cytokines in amniotic fluid of cases of PROM with infection may represent: (a) enhanced macrophage activity for immunosurveillance of the fetus; (b) a preparatory step for the initiation of labor; and (c) a valuable tests for diagnosing chorioamnioitis. The mechanism responsible for PROM in the presence or absence of infection is likely to be of different nature.