Antibody microarray analysis of amniotic fluid proteomes in women with cervical insufficiency and short cervix, and their association with pregnancy latency length.

INTRODUCTION: This study aimed to investigate amniotic fluid (AF) proteins that were differentially expressed between patients with cervical insufficiency (CI) and asymptomatic short cervix (SCX, ≤ 25 mm), and whether these proteins could be predictive of spontaneous preterm birth (SPTB) in these patients. METHOD: This was a retrospective cohort study of 129 singleton pregnant women with CI (n = 80) or SCX (n = 49) at 17 to 26 weeks who underwent amniocentesis. An antibody microarray was used to perform comparative proteomic profiling of AF from matched CI (n = 20) and SCX (n = 20) pregnancies. In the total cohort, an ELISA validation study was performed for 15 candidate proteins of interest. Subgroup analyses of patients with CI and SCX were conducted to evaluate the association between the 15 proteins and SPTB at < 32 weeks of gestation. RESULTS: Eighty-six proteins showed intergroup differences. ELISA validation confirmed significantly higher levels of AF EN-RAGE, IL-8, lipocalin-2, MMP-9, S100A8/A9, thrombospondin-2, and TNFR2 in patients with CI than in those with SCX. Multivariable analysis showed that increased AF levels of EN-RAGE, S100A8/A9, and uPA were independently associated with SPTB at < 32 weeks in patients with CI; whereas in patients with SCX, high AF levels of APRIL, EN-RAGE, LBP, and TNFR2 were independently associated with SPTB at < 32 weeks. CONCLUSIONS: Multiple AF proteins show altered expression in patients with CI compared with SCX controls. Moreover, several novel mediators involved in inflammation were identified as potential biomarkers for predicting SPTB after the diagnosis of CI and SCX. These results provide new insights into target-specific molecules for targeted therapies to prevent SPTB in patients with CI/SCX.

Comparative Analysis of Midtrimester Amniotic Fluid Cytokine Levels to Predict Spontaneous Very Pre-term Birth in Patients with Cervical Insufficiency.

PROBLEM: Few studies have investigated the roles of cytokines and chemokines in women with cervical insufficiency, and those that have done so evaluated only a limited number of cytokines in amniotic fluid. METHOD OF STUDY: A retrospective cohort study enrolled 71 patients undergoing physical examination-indicated cerclage to determine whether expanded amniotic fluid cytokine levels predict spontaneous very pre-term birth (≤32 weeks of gestation) in patients with cervical insufficiency. Analysis of multiple cytokines and chemokines was performed with the multiplex immunoassay. RESULTS: Sixty-seven amniotic fluid samples were available for analysis and assayed for 15 cytokines. Thirty-eight (56.7%) patients delivered pre-term. Of these, 26 (38.8%) were spontaneous very pre-term births. Most cytokine levels were significantly increased in the amniotic fluid from the study group when compared with those from controls. The levels of interleukin-1ß (IL-1ß), IL- 6, IL- 7, IL-15, IL-17α, tumour necrosis factor-α (TNF-α), MIP-1α, and MIP-1ß were higher in patients with a very pre-term delivery than in those with a late pre-term delivery. IL-1ß, IL-6, IL-7, IL-17α, TNF-α, and cervical dilation were independently associated with a very pre-term birth. CONCLUSION: Intra-amniotic inflammation may contribute to cervical insufficiency, and the severity of inflammation is associated with a very pre-term birth in women with cervical insufficiency.

Pregnancy-associated diseases are characterized by the composition of the systemic regulatory T cell (Treg) pool with distinct subsets of Tregs.

Dysregulations concerning the composition and function of regulatory T cells (T(regs)) are assumed to be involved in the pathophysiology of complicated pregnancies. We used six-colour flow cytometric analysis to demonstrate that the total CD4(+) CD127(low+/-) CD25(+) forkhead box protein 3 (FoxP3)(+) T(reg) cell pool contains four distinct T(reg) subsets: DR(high+) CD45RA(-), DR(low+) CD45RA(-), DR(-) CD45RA(-) T(regs) and naive DR(-) CD45RA(+) T(regs). During the normal course of pregnancy, the most prominent changes in the composition of the total T(reg) cell pool were observed between the 10th and 20th weeks of gestation, with a clear decrease in the percentage of DR(high+) CD45RA(-) and DR(low+) CD45RA(-) T(regs) and a clear increase in the percentage of naive DR(-) CD45RA(+) T(regs). After that time, the composition of the total T(reg) cell pool did not change significantly. Its suppressive activity remained stable during normally progressing pregnancy, but decreased significantly at term. Compared to healthy pregnancies the composition of the total T(reg) cell pool changed in the way that its percentage of naive DR(-) CD45RA(+) T(regs) was reduced significantly in the presence of pre-eclampsia and in the presence of preterm labour necessitating preterm delivery (PL). Interestingly, its percentage of DR(high+) CD45RA(-) and DR(low+) CD45RA(-) T(regs) was increased significantly in pregnancies affected by pre-eclampsia, while PL was accompanied by a significantly increased percentage of DR(-) CD45RA(-) and DR(low+) CD45RA(-) T(regs). The suppressive activity of the total T(reg) cell pool was diminished in both patient collectives. Hence, our findings propose that pre-eclampsia and PL are characterized by homeostatic changes in the composition of the total T(reg) pool with distinct T(reg) subsets that were accompanied by a significant decrease of its suppressive activity.

Genetics of the cervix in relation to preterm birth.

Preterm birth is the most significant problem encountered in obstetrics in the developed world. Genetic factors are thought to play a role in a proportion of preterm births, and candidate genes have been studied in several areas relevant to parturition. Abnormal cervical function, a clinical spectrum, including cervical insufficiency (CI), is a contributing factor to the overall problem of preterm birth. There are many risk factors and etiologies for CI. However, it is becoming clear that, at least in part, a genetic predisposition to CI plays a role in the condition. Specifically, genes related to connective tissue metabolism and inflammation have been shown to be associated with CI.

HLA-DR typing of women with recurrent late spontaneous abortion and unsuccessful cervical cerclage.

The release of certain cytokines, e.g. tumour necrosis factor (TNF)-alpha, in the amniotic fluid has been suggested to be a cause of preterm birth. The predisposition to excessive liberation of cytokines from peripheral leukocytes has been shown to depend partly on the individual's HLA-DR genotype. The HLA-DR1 and -DR3 alleles have previously been reported as being associated with a TNF-alpha high responder status and have also been associated with unexplained recurrent spontaneous abortions. In the present study, HLA-DR typing was performed in 10 women who had experienced recurrent very early preterm births resulting in perinatal death, or late spontaneous abortions under a clinical picture resembling that traditionally attributed to cervical incompetence. All patients had had at least one mid-trimester miscarriage in spite of the insertion of a cervical cerclage. Nine out of 10 (90%) patients had the HLA-DR phenotypes DR1 and/or DR3 compared with 37% in the background population (P < 0.005). The results suggest that HLA-DR-associated immunological factors might play a part in recurrent late spontaneous abortions and extremely preterm births under a cervical incompetence-like picture, at least in the subset of cases not treatable by cervical cerclage.

[The role of cytokines in the induction of labor, cervical ripening and rupture of the fetal membranes]. / Zur Rolle von Zytokinen bei Weheninduktion, Zervixreifung und Blasensprung.

Even today prematurity is the major cause of perinatal mortality. Prematurity has multiple causes. There is a growing body of evidence supporting the association between silent intrauterine infection and preterm birth. Bacterial products may activate macrophages ubiquitous present in the decidua, placenta and fetal membranes. These cells after activation secrete a large variety of mediators including tumour necrosis factor alpha (TNFalpha) and interleukin (IL)-1. Besides these cytokines IL-2, IL-3, IL-4, IL-6, IL-8, IL-10, epidermal growth factor, granulocyte-colony stimulating factor and transforming growth factor beta have been identified in intrauterine tissues and in the amniotic fluid. The majority of these substances (TNFalpha, IL-1, IL-2, IL-3, IL-6) can stimulate the prostaglandin-biosynthesis by intrauterine tissues (amnion, chorion, decidua), some of them have antiinflammatory effects (IL-10, transforming growth factor alpha). These effects are mediated by receptors on the target cells; specific receptor antagonists (for example for IL-1) were found in high concentrations in amniotic fluid during normal pregnancy. This cytokine network is in a sensitive balance and probably associated with an uncomplicated course of pregnancy. Systemic or localized infections as well as tissue injury initiate the induction of the prostaglandin synthesis cascade thus leading to pregnancy loss via augmented cytokine secretion. Furthermore, cytokines may be involved in the regulation of preterm and term cervical ripening. The changes in mechanical properties of the cervix are associated with a reduction of collagen content and alterations in the glycosaminoglycan pattern within the cervical extracellular matrix. IL-1 can stimulate the synthesis of collagenases, and IL-8 may play an important role in the regulation of the invasion of neutrophilic granulocytes into the cervical stroma with subsequent degranulation and release of proteases. The cytokine-stimulated collagenase production in the fetal membranes is responsible for the reduction of their tensile strength and may be associated with rupture of the membranes. The cytokine network seems to be a sensitive regulation system. Disturbances of its balance by environmental (e.g. infection) or intrauterine influences (e. g. extension by the fetus) may lead to termination of pregnancy.