Different Forms of TFF3 in the Human Endocervix, including a Complex with IgG Fc Binding Protein (FCGBP), and Further Aspects of the Cervico-Vaginal Innate Immune Barrier.

TFF3 is a typical secretory poplypeptide of mucous epithelia belonging to the trefoil factor family (TFF) of lectins. In the intestine, respiratory tract, and saliva, TFF3 mainly exists as a high-molecular-mass complex with IgG Fc binding protein (FCGBP), which is indicative of a role in mucosal innate immunity. For the first time, we identified different forms of TFF3 in the endocervix, i.e., monomeric and homodimeric TFF3, as well as a high-molecular-mass TFF3-FCGBP complex; the latter also exists in a hardly soluble form. Immunohistochemistry co-localized TFF3 and FCGBP. Expression analyses of endocervical and post-menopausal vaginal specimens revealed a lack of mucin and TFF3 transcripts in the vaginal specimens. In contrast, genes encoding other typical components of the innate immune defense were expressed in both the endocervix and vagina. Of note, FCGBP is possibly fucosylated. Endocervical specimens from transgender individuals after hormonal therapy showed diminished expression, particularly of FCGBP. Furthermore, mucus swabs from the endocervix and vagina were analyzed concerning TFF3, FCGBP, and lysozyme. It was the aim of this study to illuminate several aspects of the cervico-vaginal innate immune barrier, which is clinically relevant as bacterial and viral infections are also linked to infertility, pre-term birth and cervical cancer.

Low molecular weight heparin modulates maternal immune response in pregnant women and mice with thrombophilia.

PROBLEM: Thrombophilia is associated with pregnancy complications. Treatment with low molecular weight heparin (LMWH) improves pregnancy outcome, but the underlying mechanisms are not clear. METHODS OF STUDY: We analyzed Treg frequency in blood from thrombophilic pregnancies treated with LMWH (n = 32) or untreated (n = 33) and from healthy pregnancies (n = 39) at all trimesters. Additionally, we treated pregnant wild-type, heterozygous and homozygous factor-V-Leiden (FVL) mice with LMWH or PBS and determined Treg frequency, pro-/anti-inflammatory cytokine levels and Caspase-3-activity in placenta and decidua. RESULTS: Treg frequencies were increased in second and third trimester in LMWH-treated thrombophilic pregnancies compared to controls. Treg levels were comparable to those of normal pregnancies. Homozygous FVL mice had decreased decidual Tregs compared to wild-type mice. LMWH treatment normalized Tregs and was associated with increased decidual IL-10 mRNA. LMWH diminished Caspase-3-activity in mice of all genotypes. CONCLUSION: We demonstrated anti-apoptotic and anti-inflammatory effects of LMWH in pregnant FVL mice. LMWH increased Treg levels in mice and humans, which suggests benefits of LMWH treatment for thrombophilic women during pregnancy.

Obesity and thrombin-generation profiles in women with venous thromboembolism.

Obesity is a known risk factor for venous and arterial thrombosis but the mechanisms are still unclear. In women, obesity is correlated with low-grade inflammation and recent data show that BMI is positively associated with thrombin generation. We explored the correlations between obesity, inflammation and thrombin generation in women with increased thrombotic risk by looking at a cohort of women with prior venous thrombosis. One hundred and fifty-six women age 18-65 years were enrolled at diagnosis of first venous thromboembolism (VTE). Plasma samples were obtained at least 3 weeks after cessation of anticoagulant treatment. Thrombin generation was determined with the calibrated automated thrombography (CAT) assay and the Innovance ETP assay. Thrombin generation started later but was more pronounced with higher endogenous thrombin generation potential (ETP) determined with CAT in patients with obesity. The Innovance ETP assay showed results consistent with CAT. Furthermore, patients with obesity had significantly higher levels of fibrinogen, C-reactive protein and plasminogen activator inhibitor-I (PAI-I) than patients without obesity. Increased levels of fibrinogen were the main determinant of the prolonged lag-time in patients with obesity whereas higher levels of prothrombin could account for the difference in the ETP between the groups. We found an association between BMI and ETP values using two different methods to measure thrombin generation. Obesity correlated with increased thrombin generation in women with VTE and the main determinants of this hypercoagulable state were increased levels of fibrinogen and prothrombin. This shows a possible link between obesity, low-grade inflammation and increased thrombin generation in women at increased risk for future thrombosis.

Mechanisms of estrogen-induced venous thromboembolism.

The use of oral contraceptives (OC) is a well established risk factor for venous thrombosis. It has been known for many years that almost all haemostatic parameters i.e. plasma levels of coagulation factors, anticoagulant proteins and proteins involved in the fibrinolytic pathway change during OC use. The discovery of several risk factors of venous thrombosis in the 1990s shed new light on the association between the effects of OC on the haemostatic system and the increased risk of venous thrombosis. In this review, we summarize the current knowledge on the effects of different kinds of hormonal contraceptives (OC, transdermal contraceptives, vaginal ring and levonorgestrel-releasing intrauterine device) on haemostatic variables and the relationship between the changes of these variables and the risk of venous thrombosis.

Generation and phenotypic analysis of protein S-deficient mice.

Protein S (PS) is an important natural anticoagulant with potentially multiple biologic functions. To investigate further the role of PS in vivo, we generated Pros(+/-) heterozygous mice. In the null (-) allele, the Pros exons 3 to 7 have been excised through conditional gene targeting. Pros(+/-) mice did not present any signs of spontaneous thrombosis and had reduced PS plasma levels and activated protein C cofactor activity in plasma coagulation and thrombin generation assays. Tissue factor pathway inhibitor cofactor activity of PS could not be demonstrated. Heterozygous Pros(+/-) mice exhibited a notable thrombotic phenotype in vivo when challenged in a tissue factor-induced thromboembolism model. No viable Pros(-/-) mice were obtained through mating of Pros(+/-) parents. Most E17.5 Pros(-/-) embryos were found dead with severe intracranial hemorrhages and most likely presented consumptive coagulopathy, as demonstrated by intravascular and interstitial fibrin deposition and an increased number of megakaryocytes in the liver, suggesting peripheral thrombocytopenia. A few E17.5 Pros(-/-) embryos had less severe phenotype, indicating that life-threatening manifestations might occur between E17.5 and the full term. Thus, similar to human phenotypes, mild heterozygous PS deficiency in mice was associated with a thrombotic phenotype, whereas total homozygous deficiency in PS was incompatible with life.

The effect of the levonorgestrel-releasing intrauterine system on the resistance to activated protein C (APC).

Exogenously administered estrogens and progestogens as during combined oral contraceptive use increase the risk of venous thrombosis. The thrombin generation-based APC resistance assay is a global coagulation test that enables quantification of the net prothrombotic effect of combined oral contraceptives and that predicts the risk of thrombosis. The thrombotic risk of the levonorgestrel-releasing intrauterine system is unknown. It was the objective of this study to evaluate the thrombotic risk by comparing the APC resistance before and after insertion of a levonorgestrel-releasing or a copper-containing intrauterine device. We measured normalized APC-sensitivity ratios (nAPCsr) before and three months after insertion of the levonorgestrel-intrauterine system in 56 women and the copper-intrauterine device in 18 women. In women without hormonal contraceptive use or a pregnancy in the three months before collection of the baseline samples, nAPCsr were lower three months after insertion of the levonorgestrel-intrauterine system than at baseline (difference -0.29; 95% CI -0.04 to -0.53) and hardly changed after insertion of the copper-intrauterine device (difference -0.11; 95% CI -1.03 to 0.82). In women who switched from a combined oral contraceptive to the levonorgestrel-system the difference was more pronounced (-1.48; 95% CI -0.85 to -2.11). In this study we observed that the levonorgestrel-intrauterine system decreases the resistance to APC which indicates that the levonorgestrel-intrauterine system does not have a prothrombotic effect.

Effect of oral contraceptives on thrombin generation measured via calibrated automated thrombography.

In a study population consisting of healthy men (n = 8), women not using oral contraceptives (OC) (n = 28) and women using different kinds of OC (n = 187) we used calibrated automated thrombography (CAT) in the absence and presence of added activated protein C (APC) to compare parameters that can be obtained from thrombin generation curves, i.e. lag time, time to peak, peak height and endogenous thrombin potential (ETP). Both with and without APC, plasmas of OC users exhibited the shortest lag time and time to peak, and the highest peak height and ETP. In the absence of APC none of these parameters differed between users of OC containing different progestogens. In contrast, in the presence of APC shorter lag times and time to peak, and higher peak height and ETP were observed in plasma of users of gestodene-, desogestrel-, drospirenone- and cyproterone acetate-containing OC than in plasma of users of levonorgestrel- containing OC. The ETP determined in the absence of APC (ETP(-APC)) had no predictive value for the APCsr (r = 0.11; slope 0.9 x 10(-3); 95% CI: -0.1 x 10(-3) to 2.0 x 10(-3)) whereas the ETP measured in the presence of APC (ETP+APC) showed an excellent correlation with the APCsr (r = 0.95; slope 6.6 x 10(-3); 95% CI: 6.3 x 10(-3) to 6.9 x 10(-3)) indicating that the APCsr is entirely determined by the ETP+APC. In conclusion, OC use increases thrombin generation, but differential effects of second and third generation OCs on the protein C system likely determine the differences in the risk of venous thrombosis between these kinds of OC.