Autoimmune disease as a cause of reproductive failure

Immunologic causes and thrombophilia in recurrent pregnancy loss

Certain miscarriages result from immunologic factors, but there is no clear identification of the precise causes of recurrent pregnancy loss (RPL). Miscarriages and RPL can arise from a disruption of maternal-fetal immune homeostasis. Remodeling of the maternal uterine spiral arteries is one of the key steps for normal growth and development of the fetus. An adequate oxygen supply is necessary for correct placentation, and it is accomplished by proper vascular changes. The development of fetal tissues creates a potential immunologic problem since the fetus can express paternal antigens and, in some cases, antigens of a gamete donor. The maternal immune system actively responds to fetal antigens, and dysregulation of this crosstalk could partly explain pregnancy complications such as miscarriages and RPL. RPL resulting from thrombophilia is primarily due to acquired thrombophilia, and therefore screening and treatment should be focused on antiphospholipid antibody syndrome.

Antiphosphatidylserine antibodies and reproductive failure

Some cases of reproductive failure with autoimmune background are characterized by the involvement of autoantibodies. This occurs mainly in patients having systemic lupus erythematosus or antiphospholipid syndrome. The autoantibodies associated with reproductive failure include: a) antibodies which directly bind phospholipid (e.g., cardiolipin, phosphatidylserine, phosphatidylethanolamine); b) antiphospholipid Abs which bind the phospholipid via phospholipid-binding glycoproteins such as b2glycoprotein-I, annexin V and prothrombin; c) autoantibodies directed to laminin-I, actin, thromboplastin, the corpus luteum, prolactin, poly (ADP-ribose), thyroglobulin and mitochondrial antibodies of the M5 type. This paper will focus on the association of antiphosphatidylserine autoantibodies and reproductive failure. Future studies are likely to help to identify peptides resembling the epitope specificities associated with the specific clinical manifestations.

Recurrent pregnancy loss: evaluation and treatment

Recurrent pregnancy loss (RPL) is a multifactorial condition. Approximately half of patients with RPL will have no explanation for their miscarriages. De novo chromosome abnormalities are common in sporadic and recurrent pregnancy loss. Testing for embryonic abnormalities can provide an explanation for the miscarriage in many cases and prognostic information. Regardless of the cause of RPL, patients should be reassured that the prognosis for live birth with an evidence-based approach is excellent for most patients. The authors review current evidence for the evaluation and treatment of RPL and explore the proposed use of newer technology for patients with RPL.

Evaluation and treatment of recurrent pregnancy loss: a committee opinion

The majority of miscarriages are sporadic and most result from genetic causes that are greatly influenced by maternal age. Recurrent pregnancy loss (RPL) is defined by two or more failed clinical pregnancies, and up to 50% of cases of RPL will not have a clearly defined etiology.

Spontaneous pregnancy loss mediated by abnormal maternal inflammation in rats is linked to deficient uteroplacental perfusion

Abnormal maternal inflammation during pregnancy is associated with spontaneous pregnancy loss and intrauterine fetal growth restriction. However, the mechanisms responsible for these pregnancy outcomes are not well understood. In this study, we used a rat model to demonstrate that pregnancy loss resulting from aberrant maternal inflammation is closely linked to deficient placental perfusion. Administration of LPS to pregnant Wistar rats on gestational day 14.5, to induce maternal inflammation, caused fetal loss in a dose-dependent manner 3-4 h later, and surviving fetuses were significantly growth restricted. Pregnancy loss was associated with coagulopathy, structural abnormalities in the uteroplacental vasculature, decreased placental blood flow, and placental and fetal hypoxia within 3 h of LPS administration. This impairment in uteroplacental hemodynamics in LPS-treated rats was linked to increased uterine artery resistance and reduced spiral arteriole flow velocity. Pregnancy loss induced by LPS was prevented by maternal administration of the immunoregulatory cytokine IL-10 or by blocking TNF-α activity after treatment with etanercept (Enbrel). These results indicate that alterations in placental perfusion are responsible for fetal morbidities associated with aberrant maternal inflammation and support a rationale for investigating a potential use of immunomodulatory agents in the prevention of spontaneous pregnancy loss.

Effects of anti-phospholipid antibodies on a human trophoblast cell line (HTR-8/SVneo)

Antibodies to phospholipids (aPL) have been shown to adversely affect trophoblast invasion in vivo and in vitro. HTR-8/SVneo cells derived from first trimester of pregnancy extravillous trophoblast were studied. Matrigel invasion assay, cytochemistry and cell-based enzyme-linked immunosorbant assay (ELISA) with aPL or normal IgG was used. Our data show that aPL at 100 microg/ml decrease invasiveness of HTR-8/SVneo cells to 60% of control (p<0.01), and this was also shown for primary cytotrophoblast (to 15.5% of control, p<0.001). aPL treatment caused a significant decrease in integrin alpha(1), alpha(5), and beta(1) proteins (86%, 84%, and 87%, respectively). We conclude that HTR-8/SVneo cell culture is a suitable model to study mechanisms of action of aPL on trophoblast, which in HTR-8/SVneo cells inhibit invasion by decreasing integrins alpha(5), alpha(1), and beta(1).

Pathogenic role of antiphospholipid antibodies

The antiphospholipid antibody syndrome (APS) is characterized by recurrent arterial and venous thrombosis and/or pregnancy in association with antiphospholipid (aPL) antibodies. The pathogenic mechanisms in APS that lead to in vivo injury are incompletely understood. Recent evidence suggests that APL antibodies alter regulation of haemostasis and induce activation of complement. We will discuss the current knowledge on how aPL antibodies trigger increased inflammation and enhanced thrombotic tendency, and thereby lead to tissue damage.

Antiphospholipid antibodies and pregnancy loss: a disorder of inflammation

The antiphospholipid syndrome (APS) is a leading cause of miscarriage and maternal and fetal morbidity. APS is characterized by thrombosis and pregnancy loss that occur in the presence of antiphospholipid (aPL) antibodies. Using a mouse model of APS induced by passive transfer of human aPL antibodies, we have shown that complement activation plays an essential and causative role in pregnancy loss and fetal growth restriction, and that blocking activation of the complement cascade rescues pregnancies. Conventional treatment for APS patients is sub-anticoagulant doses of heparin throughout pregnancy. Could heparin prevent pregnancy loss by inhibiting complement? In our experimental model of APS, heparin inhibits activation of complement on trophoblasts in vivo and in vitro, and anticoagulation in and of itself is not sufficient to prevent pregnancy complications. These studies underscore the importance of inflammation in fetal injury associated with aPL antibodies and raise the importance of developing and testing targeted complement inhibitory therapy for patients with APS.

Neuroendocrine Manifestations of Phospholipid Antibody Disease Identified by Long-Term Follow-Up Study of Patients with Phospholipid Antibodies

Recurrent clinical thrombotic episodes and/or recurrent fetal wastage are the clinical features of phospholipid antibody (aPL) syndrome, which is characterized by a bland thrombosis, but is not inflammatory, as is found in other connective tissue diseases such as systemic lupus erythematosus (SLE). Previous reports have suggested that some patients with primary aPL syndrome may progress to develop other autoimmune diseases, including inflammatory diseases such as SLE. The aim of this study was to determine the long-term outcome of women with aPL antibodies, with regard to progression of their underlying autoimmune disease. To that end, a retrospective study was made of women with aPL and primary aPL syndromes who had been followed at our institution for a minimum of 3 years. Charts were reviewed, patients interviewed, and laboratory tests were performed to determine whether the clinical nature of the disease and/or its autoantibody profile had changed. Thirty patients were enrolled into the study (29 with aPL syndrome, 1 with consistent aPL and no syndrome). Follow-up ranged from 3 to 22 years. Results were as follows: The autoimmune clinical features were unchanged in 27 patients, but 3 patients developed inflammatory disease, presenting with nasal chondritis (2), cutaneous vasculitis (3), and mucosal ulcer (1). In each case, these changes occurred during pregnancy or the immediate postpartum period. One patient fulfilled criteria for SLE as seen by a change in her autoantibody profile. Another incidental finding was that three other patients were diagnosed with papillary thyroid cancer, two being diagnosed during the follow-up period.

IN CONCLUSION

(1) Inflammatory disease may develop in some patients with aPL and appears to be set off by pregnancy, a known trigger for clinical thrombotic events in aPL patients. (2) Thyroid cancer may be associated with aPL, and this association warrants further study with larger number of patients.

The role of human endogenous retroviruses in trophoblast differentiation and placental development

A major portion of the human genome appears to be of retroviral origin. These endogenous retroviral elements are expressed in a variety of normal tissues and during disease states, such as autoimmune and malignant conditions. Recently, potential roles have been described for endogenous retroviral envelope proteins in normal differentiation of human villous cytotrophoblast into syncytiotrophoblast. This article provides a brief critical review of the current state of knowledge concerning the expression of the env regions of three endogenous retroviral elements: ERV-3, HERV-W, and HERV-FRD. A testable model of villous cytotrophoblast differentiation is constructed, in which a complementary expression of endogenous retroviral envelope proteins initiates hCG production, decreased cell proliferation, and intercellular fusion.

TNF-alpha is a critical effector and a target for therapy in antiphospholipid antibody-induced pregnancy loss

The antiphospholipid syndrome (APS) is characterized by recurrent fetal loss, intrauterine growth restriction, and vascular thrombosis in the presence of antiphospholipid (aPL) Abs. Our studies in a murine model of APS induced by passive transfer of human aPL Abs have shown that activation of complement and recruitment of neutrophils into decidua are required for fetal loss, and emphasize the importance of inflammation in aPL Ab-induced pregnancy loss. In this study, we examine the role of TNF-alpha in pregnancy complications associated with aPL Abs in a murine model of APS. We show that aPL Abs are specifically targeted to decidual tissue and cause a rapid increase in decidual and systemic TNF-alpha levels. We identify the release of TNF-alpha as a critical intermediate that acts downstream of C5 activation, based on the fetal protective effects of TNF-alpha deficiency and TNF blockade and on the absence of increased TNF-alpha levels in C5-deficient mice treated with aPL Abs. Our results suggest that TNF-alpha links pathogenic aPL Abs to fetal damage and identify TNF blockade as a potential therapy for the pregnancy complications of APS.

Recurrent implantation failure in assisted reproduction: how to counsel and manage. B. Treatment options that have not been proven to benefit the couple

The success of assisted reproduction, although gradually increasing over the years, is still less than satisfactory. Many couples have benefited from this treatment; however, many have also been left frustrated following multiple failed attempts. Couples who fail to conceive after multiple IVF/intracytoplasmic sperm injection (ICSI) treatments often seek treatment options that are new and that have not been offered before. Some of these include immunological testing and treatment, allogenic lymphocyte therapy, intratubal transfer of zygotes and embryos, blastocyst transfer, sequential embryo transfer, assisted hatching, co-cultures, and preimplantation genetic screening for aneuploidy. Although the evidence behind some of these is more robust, most suffer from lack of well designed randomized trials comparing them with other treatment options. Randomized studies are extremely difficult to conduct, as couples will resist being randomized into a treatment group where previously failed procedures will be repeated. In the mean time, assisted reproduction programmes should resist offering treatment options that are not evidence based, or at least they should share with the couple the information that is available and should stress that none of these is a panacea for their problem.

Antiphosphatidylserine Antibodies Affect Rat Yolk Sacs in Culture: a Mechanism for Fetal Loss in Antiphospholipid Syndrome

PROBLEM

A variety of reproductive impairments have been reported in the context of the antiphospholipid syndrome (APS). APS is associated with the presence of antibodies to negatively charged phospholipids that may affect the outcome of pregnancy.

METHOD OF STUDY

Rat embryos were cultured within their yolk sacs. The effects of two antiphosphatidylserine monoclonal aPS antibodies (HL5B, RR7F) regarding their influence on growth and apoptotic events of the yolk sacs, as well as on growth and the morphology of the embryos, were studied.

RESULTS

Exposure of rat embryos and their yolk sacs to aPS inhibited yolk sac growth. Moreover, increased number of apoptotic events of giant cells in the aPS-exposed ectoplacental cone was found in comparison with control IgG-exposed giant cells (P < 0.05). No significant damage was observed in the embryos.

CONCLUSIONS

The results suggest that aPS affect growth and apoptosis of rat ectoplacental cone.