Silvia D'Ippolito

Obstetric antiphospholipid syndrome: A recent classification for an old defined disorder

Obstetric antiphospholipid syndrome (APS) is now being recognized as a distinct entity from vascular APS. Pregnancy morbidity includes >3 consecutive and spontaneous early miscarriages before 10weeks of gestation; at least one unexplained fetal death after the 10th week of gestation of a morphologically normal fetus; a premature birth before the 34th week of gestation of a normal neonate due to eclampsia or severe pre-eclampsia or placental insufficiency. It is not well understood how antiphospholipid antibodies (aPLs), beyond their diagnostic and prognostic role, contribute to pregnancy manifestations. Indeed aPL-mediated thrombotic events cannot explain the obstetric manifestations and additional pathogenic mechanisms, such as a placental aPL mediated complement activation and a direct effect of aPLs on placental development, have been reported. Still debated is the possible association between aPLs and infertility and the effect of maternal autoantibodies on non-vascular manifestations in the babies. Combination of low dose aspirin and unfractionated or low molecular weight heparin is the effective treatment in most of the cases. However, pregnancy complications, in spite of this therapy, can occur in up to 20% of the patients. Novel alternative therapies able to abrogate the aPL pathogenic action either by interfering with aPL binding at the placental level or by inhibiting the aPL-mediated detrimental effect are under active investigation.

Adipokines, an adipose tissue and placental product with biological functions during pregnancy.

Latter half of pregnancy is characterized by a “physiological diabetogenic state” since changes in insulin‐sensitivity have been well documented. These changes ensure continuous supply of nutrients to the growing fetus. In the last years the role of adipocyte‐derived signaling molecules, collectively known as adipokines has been object of different in vitro and in vivo studies. Of interest, adipokines and/or their receptors are expressed in the placental tissue which, therefore, can contribute to development of maternal insulin‐resistance and, as a consequence, fetal growth. Leptin, adiponectin, and resistin represent the most well studied adipokines and, with the exception of adiponectin, their serum and placental levels increase as pregnancy progresses. High levels of adipokines have also been detected in umbilical plasma hence suggesting a possible role on fetal development and metabolism; however, it remains still unclear if such adipokines can directly stimulate fetal tissues development acting as growth factors. In addition to their well known metabolic effects, we also reported studies describing the role of adipokines in promoting proliferation and invasiveness of trophoblast cells and affecting local angiogenic processes. These observations strongly suggest that adipokines, by alternatively interfering with placental development, may affect pregnancy outcome and fetal growth. However, further studies are needed to better understand the local regulation of their expression.

Antibodies Anti-Caga Cross-React with Trophoblast Cells: A Risk Factor for Pre-Eclampsia?

Previous studies reported an epidemiological association between CagA‐positive H. pylori strains and pre‐eclampsia. As antibodies anti‐CagA cross‐react with endothelial cells and trophoblast cells show an endothelial phenotypic profile, we hypothesized that anti‐CagA antibodies may recognize antigens of cytotrophoblast cells, thus impairing their function.

Antiphospholipid Antibodies Affect Human Endometrial Angiogenesis: Protective Effect of a Synthetic Peptide (TIFI) Mimicking the Phospholipid Binding Site of β2glycoprotein I

Aim of our study was to investigate whether TIFI, a syntetic peptide able to compete with anti‐phospholipid antibodies (aPL) in the binding to endothelium, may restore aPL‐inhibited endometrial angiogenesis.

Inflammosome in the human endometrium: further step in the evaluation of the “maternal side”

OBJECTIVE To investigate the expression of inflammosome components (NALP-3, associated speck-like protein containing a CARD [ASC]) and their activation (caspase-1, interleukin [IL]-1β, and IL-18 secretion) in the human endometrium from fertile and women with history of recurrent pregnancy loss (RPL). DESIGN Experimental study. SETTING University hospital. PATIENT(S) Ten fertile women (control group [CTR]) and 30 women with RPL. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Endometrial samples were collected by hysteroscopy during the putative window of implantation and evaluated for chronic endometrial inflammation by hystopathological analysis. Inflammosome expression was analysed by immunohystochemical staining (27 RPL and 10 CTR women). The expression of NALP-3 and ASC protein was quantified by Western blot (30 RPL and 10 CTR women). Caspase-1 activation and IL-1β and IL-18 secretion was quantified by ELISA (30 RPL and 10 CTR women). RESULT(S) We observed a significantly increased expression of inflammasome NALP-3 and ASC protein, an increased activation of caspase-1, and increased levels of IL-1β and IL-18 in RPL endometrium compared with CTR. CONCLUSION(S) Abnormal activation of endometrial innate immunity by means of inflammosome, stimulated by pathogen- or damage-associated molecular patterns, may represent an additional mechanism, currently not investigated, negatively interfering with endometrial receptivity. More studies are required [1] to identify the primary trigger of endometrial inflammosome activation and its clinical impact in the occurrence of RPL; and [2] to validate the inflammosome components as a novel family of endometrial biomarkers and promising therapeutic targets in RPL.

Emerging nonanticoagulant role of low molecular weight heparins on extravillous trophoblast functions and on heparin binding-epidermal growth factor and cystein-rich angiogenic inducer 61 expression

OBJECTIVE To examine the effects of low molecular weight heparins (LMWHs) on extravillous trophoblast (EVTC) invasiveness and on EVTC expression/secretion of heparin binding-EGF (HB-EGF) and cystein-rich angiogenic inducer 61 (Cyr61), both of which are involved in the process of EVTC invasion. Furthermore, to investigate the intracellular DNA binding activity of activator protein (AP)-1. DESIGN Experimental study. SETTING Department of Obstetrics Gynecology, Università Cattolica del Sacro Cuore, Rome, Italy. PATIENT(S) Cultures of primary EVTC cells isolated from patients with first trimester unexplained recurrent miscarriage. INTERVENTION(S) The effects of LMWHs on EVTC invasiveness were examined by an in vitro matrigel invasion assay. Matrix metalloprotease-2 activity (MMP-2) was examined by gelatin zimography. HB-EGF and Cyr61 expression and secretion were studied by Western blot analysis and ELISA assay. AP-1 activity was measured through a multiwell colorimetric assay. MAIN OUTCOME MEASURE(S) The EVTC invasiveness, the expression/secretion of HB-EGF and Cyr61 proteins, and the AP-1 DNA binding activity in the presence of increasing concentrations of LMWHs were investigated. RESULT(S) Both LMWHs, and primarily tinzaparin, increased EVTC invasiveness, by enhancing the MMP-2 proteolytic activity, and induced the expression/secretion of HB-EGF and Cyr61 in EVTC. This effect was mediated by an increased DNA binding activity of AP-1. CONCLUSION(S) Both LMWHs are able to promote EVTC development because they are able to stimulate the EVTC invasive properties. Our results may provide a possible biological rationale for the clinical use of LMWH for placental-mediated pregnancy complications unrelated to prothrombotic disorders.

Human leukocyte antigen (HLA) DQ2/DQ8 prevalence in recurrent pregnancy loss women

OBJECTIVE Over the last few years, medical scholars have reported the significant association between recurrent pregnancy loss (RPL) and celiac disease (CD). Various pathogenic mechanisms underlying the pregnancy failure in CD have been suggested: among them the ability of anti-transglutaminase antibodies to impair the trophoblast invasiveness and endometrial endothelial cells differentiation and disrupt early placentation. CD shows a complex non-Mendelian pattern of inheritance, involving major histocompatibility complex (MHC) genes. The strongest effects are mapped to the classical human leukocyte antigen (HLA)-DQA1 and HLA-DQB1 genes. Specifically, the common haplotypes DQ2.5, DQ2.2, and DQ8 have been shown to increase CD risk by six-fold on average. MHC region contains genes with immunological functions and is responsible for the strongest association signals observed in most immune-mediated diseases. The aim of our study was to investigate the prevalence of the HLA-DQ2/DQ8 haplotypes in RPL, outside of CD. METHODS The study population included women with history of RPL (≥3 spontaneous pregnancy losses) and women with at least two previous uncomplicated term pregnancies (control group, CTR). All women gave their informed consent to use their data for research purposes. RESULTS 97 RPL women and 55 CTR were considered in the study. Mean age of the RPL sample was 37.7 (standard deviation, SD, 3.0; min 27; max 39). Mean age of the control group was 35.6 (SD 3.0; min 26years; m, max 38). A significantly increased prevalence of HLA-DQ2/DQ8 haplotype positivity was found in RPL population compared to control women (52.6% vs 23.6%; p<0.01). CONCLUSIONS Our observations show for the first time a higher proportion of individuals HLA DQ2/DQ8 positive in women with RPL as compared to controls (and to general population estimates). Further studies are needed to better understand (i) the possible pathogenic mechanism to this observation; (ii) the clinical and therapeutic implications of our observation in order to provide a new approach to RPL couples.

Human IgG Antinuclear Antibodies Induce Pregnancy Loss in Mice by Increasing Immune Complex Deposition in Placental Tissue: In Vivo Study

A threefold higher prevalence of antinuclear antibodies (ANA) has been reported in patients with recurrent pregnancy loss (RPL). Nevertheless, the role of ANA in reproductive failure is still unclear. The aim of this study was to investigate the role of ANA during early pregnancy in vivo.