Intra‐Amniotic Administration of HMGB1 Induces Spontaneous Preterm Labor and Birth

Nearly 65 years have passed since Peter Medawar posed the following question: “How does the pregnant mother contrive to nourish within itself, for many weeks or months, a fetus that is an antigenically foreign body.” Now, understanding of reproductive immunology has demonstrated that the HLA antigens in the placenta are non‐classical and do not induce rejection. In the placenta and in tumors, 50% or more of the cells are cells of the immune system and were once thought to be primed and ready for killing tumors or the “fetal transplant” but these cells are not potential killers but abet the growth of either the tumor or the placenta. We believe that these cells are there to create an environment, which enhances either placental or tumor growth. By examining the similarities of the placenta's and tumor's immune cells, novel mechanisms to cause tumors to be eliminated can be devised.     

Amniotic fluid interleukin-1 beta and interleukin-6, but not interleukin-8 correlate with microbial invasion of the amniotic cavity in preterm labor

Citation
Marconi C, Ramos BRA,
Peraçoli JC, Donders GGG, Silva MG. Amniotic fluid interleukin‐1 betaand interleukin‐6, but not interleukin‐8 correlate with microbial invasion of the amniotic cavity in preterm labor. Am J Reprod Immunol 2011; 65: 549–556 Problem We compared the frequency of intra‐amniotic infection in preterm labor (PL) with women not in labor, and correlated infection with amniotic fluid (AF) cytokines. Detailed identification of species, especially mycoplasmata, was tried to improve our understanding of the pathogenesis of PL. Method of study AF from 20 women with PL and 20 controls were evaluated. Infection was detected by PCR for Mycoplasma hominis, Ureaplasma urealyticum and 16S rRNA bacterial gene, which was cloned and sequenced for bacterial identification. Interleukin (IL)‐1β, IL‐6, IL‐8 and tumor necrosis factor (TNF)‐α levels were measured by ELISA. Results Frequency of intra‐amniotic infection is higher in PL (40.0%). Sequencing‐based method identified Bacteroides fragilis, Prevotella bivia and Leptotrichia amnionii, in addition to Mycoplasma species detected by PCR. AF infection correlated with increased IL‐1β and IL‐6 levels. Conclusion The frequency of intra‐amniotic infection, especially M. hominis, in PL women who delivered with 7 days, is high and correlates with high IL‐1β and IL‐6 levels, but not IL‐8.     

Preterm labor and preterm premature rupture of membranes have a different pattern in the involved compartments of acute histologoic chorioamnionitis and/or funisitis: Patho‐physiologic implication related to different clinical manifestations

It is unknown whether histo‐topographic findings about the involved compartments (i.e., choriodecidua, amnion, chorionic‐plate) of acute‐histologic chorioamnionitis (acute‐HCA) and/or funisitis according to the presence or absence of intra‐amniotic inflammation (IAI) and/or fetal inflammatory response syndrome (FIRS) are different between preterm labor and intact membranes (PTL) and preterm premature rupture of membranes (preterm‐PROM). The involved compartments of acute‐HCA and/or funisitis were examined in 161 singleton preterm‐births (<34 weeks) due to PTL (n = 88) and preterm‐PROM (n = 73). The study‐population was divided into IAI(?)/FIRS(?), IAI(+)/FIRS(?), and IAI(+)/FIRS(+) groups according to the presence or absence of IAI (amniotic‐fluid MMP‐8 ≥ 23 ng/ml) and/or FIRS (umbilical‐cord plasma CRP ≥ 200 ng/ml). Histological inflammation was not detected in any‐compartment except choriodecidua in IAI(?)/FIRS(?) group with PTL while inflammation appeared in all‐compartment0s (choriodeciduitis‐46.2 %; amnionitis‐23.1 %; funisitis‐30.8 %; chorionic‐plate inflammation‐7.7 %) in IAI(?)/FIRS(?) group with preterm‐PROM. IAI(+)/FIRS(?) group had a significantly higher frequency of inflammation in each‐compartment than IAI(?)/FIRS(?) group in PTL (each‐for P < 0.01), but not preterm‐PROM (each‐for P > 0.1). However, IAI(+)/FIRS(+) group had a significantly higher rate of inflammation in each compartment than IAI(+)/FIRS(?) group in both PTL and preterm‐PROM (each‐for P < 0.05). We first demonstrated that PTL and preterm‐PROM had a different pattern in the involved compartments of acute‐HCA and/or funisitis in the IAI(?)/FIRS(?‐) group and in the change of involved compartments from IAI(?)/FIRS(?) to IAI(+)/FIRS(?)     

Granulocytic myeloid‐derived suppressor cells (GR‐MDSC) accumulate in cord blood of preterm infants and remain elevated during the neonatal period

Preterm delivery is the leading cause of perinatal morbidity and mortality. Among the most important complications in preterm infants are peri‐ or postnatal infections. Myeloid‐derived suppressor cells (MDSC) are myeloid cells with suppressive activity on other immune cells. Emerging evidence suggests that granulocytic MDSC (GR‐MDSC) play a pivotal role in mediating maternal–fetal tolerance. The role of MDSC for postnatal immune‐regulation in neonates is incompletely understood. Until the present time, nothing was known about expression of MDSC in preterm infants. In the present pilot study, we quantified GR‐MDSC counts in cord blood and peripheral blood of preterm infants born between 23 + 0 and 36 + 6 weeks of gestation (WOG) during the first 3 months of life and analysed the effect of perinatal infections. We show that GR‐MDSC are increased in cord blood independent of gestational age and remain elevated in peripheral blood of preterm infants during the neonatal period. After day 28 they drop to nearly adult levels. In case of perinatal or postnatal infection, GR‐MDSC accumulate further and correlate with inflammatory markers C‐reactive protein (CRP) and white blood cell counts (WBC). Our results point towards a role of GR‐MDSC for immune‐regulation in preterm infants and render them as a potential target for cell‐based therapy of infections in these patients.     

Changes in the Fetal and Neonatal Cytokine Profile in Pregnancies Complicated by Fetal Growth Restriction

Fetal growth restriction (FGR) is a major complication of pregnancy with unknown etiology which results in marked fetal, neonatal and long‐term morbidity, and mortality. FGR is likely to result from suboptimal placental implantation and perturbed immunological interactions. The diagnostic criteria for FGR vary between studies and the condition often occurs with pre‐eclampsia. Here, we review published studies of fetal and neonatal cytokines in FGR and compare these with studies of small for gestational age, pre‐eclampsia and pregnancies delivering pre‐term.     

ORIGINAL ARTICLE: Sperm Antibodies,Intra‐Acrosomal Sperm Proteins,and Cytokines in Semen in Men from Infertile Couples

Problem The aim of this study was to investigate seminal sperm‐agglutinating antibodies, intra‐acrosomal proteins, sperm head abnormalities, and cytokines (IL‐1β, IL‐2, IL‐4, IL‐5, IL‐6, IL‐8, IL‐10, IL‐12p70 TNF‐α, and IFN‐γ) in men from infertile couples. Method of study The direct mixed anti‐immunoglobulin reaction test for IgG, IgA, and IgE in semen, and immunocytochemical method using monoclonal antibodies and indirect immunofluorescence for the examination of intra‐acrosomal proteins in the spermatozoa were used. Cytokines in seminal plasma were determined by multiplex immunoanalytic xMAP (LUMINEX) technology. Results Sperm‐agglutinating antibodies, IgG and IgA, in seminal plasma were found to be more in asthenospermatic and oligoasthenospermatic men than in normospermatic men. Sperm head pathology and very low amounts of acrosomal proteins were frequently detected in pathologic semen samples. Cytokine levels defined as ‘high’ (based on the 75 percentile for each cytokine in all groups) were obtained especially for IL‐8, IL‐5, IL‐6, and IL‐10. The high cellularity in semen was correlated with higher IL‐5. Conclusion Immunologic cause of male infertility is a very important risk factor in the pathogenesis of sperm cells. Sperm autoantibodies and the presence of intra‐acrosomal factors must be studied together, cytokines according to accessory cellularity in the semen.     

Modulation of amniotic fluid activin-a and inhibin-a in women with preterm premature rupture of the membranes and infection-induced preterm birth

Citation Rosenberg VA, Buhimschi IA, Dulay AT, Abdel‐Razeq SS, Oliver EA, Duzyj CM, Lipkind H, Pettker CM, Buhimschi CS. Modulation of amniotic fluid activin‐A and inhibin‐A in women with preterm premature rupture of the membranes and infection‐induced preterm birth. Am J Reprod Immunol 2012; 67: 122–131 Problem Activins and inhibins are important modulators of inflammatory processes. We explored activation of amniotic fluid (AF) activin‐A and inhibin‐A system in women with intra‐amniotic infection and preterm premature rupture of the membranes (PPROM). Method of study We analyzed 78 AF samples: ‘2nd trimester‐control’ (n = 12), ‘3rd trimester‐control’ (n = 14), preterm labor with intact membranes [positive‐AF‐cultures (n = 13), negative‐AF‐cultures (n = 13)], and PPROM [positive‐AF‐cultures (n = 13), negative‐AF‐cultures (n = 13)]. Activin‐A levels were evaluated ex‐vivo following incubation of amniochorion and placental villous explants with Gram‐negative lipopolysaccharide (LPS) or Gram‐positive (Pam3Cys) bacterial mimics. Ability of recombinant activin‐A and inhibin‐A to modulate inflammatory reactions in fetal membranes was explored through explants’ IL‐8 release. Results Activin‐A and inhibin‐A were present in human AF and were gestational age‐regulated. Activin‐A was significantly upregulated by infection. Lower inhibin‐A levels were seen in PPROM. LPS elicited release of activin‐A from amniochorion, but not from villous explants. Recombinant activin‐A stimulated IL‐8 release from amniochorion, an effect that was not reversed by inhibin‐A. Conclusion Human AF activin‐A and inhibin‐A are involved in biological processes linked to intra‐amniotic infection/inflammation‐induced preterm birth.     

All‐Trans Retinoic Acid and Intra‐Amniotic Endotoxin‐Mediated Effects on Fetal Sheep Lung

All‐trans retinoic acid (RA) is a potent modulator of lung development. Chorioamnionitis, which is frequently associated with preterm birth, causes fetal lung inflammation and improves lung function but also results in alveolar simplification and microvascular injury. Endotoxin‐mediated chorioamnionitis reduces RA concentration in the fetal lung to 16% of control values. We hypothesized that administration of RA to the fetus before induction of chorioamnionitis would preserve septation of the distal airspaces. Time‐mated ewes with singletons were assigned to receive a fetal intramuscular treatment with 20,000 IU of RA in olive oil (or olive oil only) 3 hr prior to intra‐amniotic injection of endotoxin (20 mg, E. coli 055:B5) or saline, at 124‐day gestational age and 7 days after the fetal treatment. The right cranial lung lobe was processed for morphometric analysis. RA treatment did not affect chorioamnionitis‐induced fetal and systemic inflammation or interleukin‐8 concentrations in lung tissue. RA administration alone did not alter lung structure. Relative to control lungs (5 ± 3 mL/kg), lung volume increased similarly with endotoxin (22 ± 4 mL/kg) or RA plus endotoxin (20 ± 3 mL/kg; P < 0.05). Alveolar wall thickness was 4.2 ± 0.3 μm after endotoxin‐induced chorioamnionitis, 6.0 ± 0.4 μm in controls (P < 0.05 versus endotoxin) and 5.5 ± 0.2 μm after RA and endotoxin (P < 0.05 versus control, n.s. versus endotoxin). The ratio of airspace versus tissue was 4.6 ± 0.3 in endotoxin‐induced chorioamnionitis, 2.1 ± 0.3 in controls and 4.1 ± 0.5 after RA and endotoxin. We conclude that fetal treatment with RA did not prevent inflammation‐induced alveolar simplification. Anat Rec, 2008. © 2008 Wiley‐Liss, Inc.     

ORIGINAL ARTICLE: Activation of the Alternative Pathway of Complement is a Feature of Pre‐Term Parturition but not of Spontaneous Labor at Term

Citation Vaisbuch E, Romero R, Erez O, Mazaki‐Tovi S, Kusanovic JP, Soto E, Dong Z, Chaiworapongsa T, Kim SK, Ogge G, Pacora P, Yeo L, Hassan SS. Activation of the alternative pathway of complement is a feature of pre‐term parturition but not of spontaneous labor at term. Am J Reprod Immunol 2010; 63: 318–330 Problem Plasma concentrations of fragment Bb (FBb) are a marker for activation of the alternative pathway of the complement system. High concentrations of FBb in maternal blood, as early as the first trimester, are associated with subsequent spontaneous pre‐term delivery <34 weeks of gestation. The aim of this study was to determine whether spontaneous pre‐term labor (PTL) with intact membranes, intra‐amniotic infection/inflammation (IAI) or labor at term are associated with alterations in circulating maternal FBb concentrations. Method of study This cross‐sectional study included women in the following groups: (i) non‐pregnant (n = 40); (ii) normal pregnancy (gestational age range 20–36, 6/7 weeks, n = 63); (iii) women at term not in labor (n = 70); (iv) women at term in spontaneous labor (n = 59); (v) patients with an episode of PTL who delivered at term (n = 62); (vi) PTL without IAI who delivered pre‐term (n = 30); and (vii) PTL with IAI who delivered pre‐term (n = 67). Maternal plasma FBb concentrations were determined by ELISA. Results (i) Among patients with PTL, those who had a pre‐term delivery either with IAI (1.21 μg/mL, IQR 0.77–2.16) or without IAI (1.13 μg/mL, IQR 0.92–2.08) had a higher median maternal plasma FBb concentration than those who delivered at term (0.86 μg/mL, IQR 0.64–1.57; P = 0.007 and P = 0.026, respectively); (ii) there was no difference in the median plasma FBb concentration between patients with and without IAI who delivered pre‐term (P = 0.9); (iii) in contrast, spontaneous labor at term was not associated with a significant change in the maternal plasma FBb concentration (P = 0.8); (iv) maternal plasma concentration of FBb did not differ significantly between normal pregnant women and the non‐pregnant controls (P = 0.8) and were not correlated with advancing gestational age (r = ?0.28, P = 0.8). Conclusion (i) Pre‐term parturition is associated with activation of the alternative complement pathway in maternal circulation; (ii) such activation is not detectable in spontaneous labor at term; (iii) IAI does not explain the activation of the alternative pathway of complement in PTL. Collectively, these observations suggest that pre‐term and term labors have fundamental differences in the regulation of innate immunity.