Antiphospholipid antibodies and recurrent pregnancy loss

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

PROBLEM

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.

METHOD OF STUDY

We used pregnant mice treated with immunoglobulin G (IgG) obtained from normal healthy subjects (NHS); ANA(+) sera of patients with RPL; and ANA(+) sera from women with uncomplicated pregnancies (HW). Placental immunohistochemical/immunofluorescence staining was performed to detect complement and immune complex deposition. ELISA was performed to evaluate complement levels.

RESULTS

ANA(+) IgG from RPL women significantly increased embryo resorption rate, reduced C3, and increased C3a serum levels compared to NHS IgG or ANA(+) -HW IgG. Increased C3 deposition and increased immune complex staining in placental tissues from mice treated with ANA(+) -RPL IgG fraction compared to NHS- and ANA(+) -HW-IgG-treated mice were found.

CONCLUSION

ANA(+) IgG injection in mice is able to induce fetal resorption and complement activation. The presence on placental tissues of immune complexes and complement fragments suggests the complement activation as a possible mechanism of placental damage.

Influence of antiphospholipid antibodies on pregnancy outcome in women undergoing in vitro fertilization and embryo transfer

PROBLEM

Antiphospholipid antibodies (APA) are thought to be involved in recurrent pregnancy loss. Therefore, we investigated the impact of APA on pregnancy outcome in women undergoing in vitro fertilization and embryo transfer (IVF-ET).

METHOD OF STUDY

Blood samples taken from 54 Korean women referred for IVF were tested for the presence of APA, anticardiolipin antibody IgG and IgM and lupus anticoagulant. The standard gonadotropin-releasing hormone agonist long protocol was used for ovarian stimulation.

RESULTS

Nine patients (16.7%) were positive and 45 (83.3%) were negative for APA. There were no significant differences between the two groups in clinical characteristics such as age, infertility duration, and response to controlled ovarian hyperstimulation. However, pregnancy outcome significantly differed between the two groups (p < 0.05). The APA positive group and APA negative group had abortion rates of 62.5% and 20.0%, respectively and delivery rates of 37.5% and 80.0%, respectively.

CONCLUSION

The presence of APA in women undergoing IVF-ET was associated with a poor pregnancy outcome.

Pregnancy loss and endometriosis: pathogenic role of anti-laminin-1 autoantibodies

Laminin-1 is a major multifunctional glycoprotein that forms an integral part of the scaffolding network of basement membranes, and is the earliest synthesized component during embryogenesis. This protein (alpha1beta1gamma1) plays an important role in basement membrane assembly and epiblast differentiation during embryonic development. Anti-laminin-1 autoantibodies are known to cause infertility and recurrent spontaneous abortion in animals. Recently, we reported that the presence of IgG anti-laminin-1 antibodies (Abs) in the blood is significantly associated with recurrent first-trimester miscarriages and subsequent negative pregnancy outcomes. Interestingly, these antibodies are also strongly associated with infertility, especially infertility caused by endometriosis. Laminin-alpha1, laminin-beta1, and laminin-gamma1 mRNAs were also detected in 90% of endometriotic lesions, and all laminin-alpha1, laminin-beta1, and laminin-gamma1 chains were localized to the basement membranes of glandular epithelium in endometriotic peritoneal lesions. ELISA showed specific reactivity of the autoantibodies to a particular region of the laminin-1 molecule, that is, the alpha1 chain G domain. IgM monoclonal anti-laminin-1 Abs, which we recently established, also recognized the G domain and cross-reacted with human alpha1 chain located in the basement membrane of the glandular epithelium of human endometrium. We also established an animal model that produced high titers of anti-laminin-1 Abs after immunization with mouse laminin-1. Anti-laminin-1 Abs from the immunized mice caused a higher fetal resorption rate with lower embryonic and placental weights. Thus, anti-laminin-1 Abs may be important in the development of autoimmune-mediated reproductive failures, and the assessment of the such antibodies may provide a novel means for noninvasive diagnosis of endometriosis.

Drug intervention in early pregnancy after assisted reproductive technology

Implantation in humans is a complex, closely regulated, highly selective and relatively poorly understood process. Humans have the highest rate of miscarriage in mammals and various pharmacological manipulations have been used to minimize pregnancy losses in both spontaneous pregnancies and pregnancies resulting from assisted reproduction technology. The widespread application of protocols using numerous drugs in assisted reproduction treatment has led to an increasing number of pregnancies exposed to these drugs. The vast majority of these protocols have been based on data from a few observational and often retrospective clinical studies. This paper reviews the recent literature on drug interventions in early pregnancy after assisted reproduction treatment. It is concluded that there are still numerous issues about the safety of most drugs for both the women and their fetus. In many cases, the benefits are theoretical and the possible long-term side-effects are untested. There is an urgent need for more epidemiological studies and randomized controlled trials to explore the use, efficacy and side-effects of both old and new drugs in early pregnancy after assisted reproduction treatment.

Pregnancy outcome in women with antiphospholipid syndrome and alloimmunity: a case report

CONTEXT

Patients with antiphospholipid syndrome and alloimmunity have poor pregnancy outcomes. Several diagnostic and therapeutic options exist for these disorders, although there is no consensus as to the best treatment.

CASE REPORT

We present here the clinical course and treatment of a woman with a history of two miscarriages who joined our program 10 years ago and has been followed up ever since. After antiphospholipid syndrome and alloimmune failure were diagnosed, she was given preconceptional treatment using unfractionated heparin, aspirin, prednisone and lymphocyte immunizations. She delivered two premature babies in the following two pregnancies. At present both children are healthy and are attending school. The fifth pregnancy was unsuccessful, in spite of having undergone a similar but postconceptional therapeutic scheme. We discuss this case focusing on the pathogenic mechanisms and the therapeutic aspects of these disorders.

Antiphospholipid antibodies in implantation failures

PROBLEM

The amino phospholipids (PL), phosphatidylserine (PS) and phosphatidylethanolamine (PE) are distributed asymmetrically in the plasma membranes of eucaryotic cells. This arrangement involves active transport of PS and PE from the outer to inner membrane leaflet by an aminophospholipid translocase (flipase). Cell activation, injury and programmed cell death (apoptosis) cause collapse of the PS/PE asymmetry by activation of another enzyme system, scramblase. Unlike other cells, the developing trophoblast exteriorizes PS during its differentiation.

METHODS OF STUDY

An analysis of published and unpublished data.

RESULTS

The trophoblast is targeted by antiphospholipid antibodies (aPL), especially to PS (aPS). Cardiolipin is not present in the trophoblast plasma membrane, nonetheless, anticardiolipin (aCL) has been implicated in trophoblast pathology. The aPS and aCL are often crossreactive. Both animal and in vitro experimental models have shown monoclonal and polyclonal aPS and aCL to specifically destroy trophoblast, inhibit syncytium formation, halt human chorionic gonadatropin (hCG) production, and limit trophoblast invasion. Antibodies to PE (aPE) have not been well characterized, however, recent reports from several independent laboratories document that aPE are associated significantly with very early (embryonic) recurrent pregnancy loss (RPL). Umeda and coworkers have shown that during cytokinesis (late telophase) of Chinese hamster ovary (CHO) cells, formation of PE rafts in cleavage furrows is required for completion of cell division and formation of daughter cells. This raises the question whether aPE might interfere with implantation and cell division during embryogenesis.

CONCLUSIONS

A role for aPL in implantation failure and occult pregnancy loss constitutes the basis of this overview.

Mechanisms of syncytial fusion: a review

Syncytial fusion of trophoblast is a key process in placental morphogenesis and physiology. Disturbed syncytial fusion may lead to a number of pregnancy-associated pathologies. The mechanisms regulating syncytial fusion are only partly understood. This review tries to summarize the available knowledge on trophoblast fusion, originating from different scientific disciplines. Among the themes addressed in this paper are: morphogenesis and functions of syncytiotrophoblast; early apoptotic events and changes in plasmalemmal phospholipid orientation; proteins involved in membrane fusion: ADAMs and retrovirally-derived proteins and short-lived proteolipid intermediates in membrane fusion. Deeper understanding of syncytiotrophoblast fusion in future studies is only to be anticipated from collaborative studies focusing in parallel on physicochemical events in the participating plasmalemmas, early apoptotic/differentiation events preceding the fusion and role of the fusogenic membrane proteins.

Anticardiolipin antibodies in ectopic pregnancies

BACKGROUND

Anticardiolipin auto-antibodies are known to be inflicted in recurrent pregnancy losses and other adverse outcomes of pregnancy. However, their role in extrauterine pregnancies is unknown.

OBJECTIVE

To clarify the association between anticardiolipin antibodies and extrauterine pregnancies.

PATIENTS AND METHODS

About 30 patients with ectopic pregnancies confirmed histologically and 40 control subjects with intrauterine pregnancies were studied. Mean duration of pregnancy was 38 and 39 days, respectively. Serum levels of IgG, IgA, and IgM antibodies against cardiolipin were measured. In addition, measurements of human chorionic gonadotropin (beta hCG) and progesterone were made.

RESULTS

Mean levels of IgA and IgM but not IgG antibodies were significantly higher in patients with ectopic pregnancies than in normal pregnant women. Distribution frequency histograms revealed that a subgroup of ectopic pregnancies exhibit antibody titers corresponding to that of intrauterine pregnancies, and others showing elevated levels. Markedly elevated antibody levels were observed in patients having low levels of beta hCG and/or progesterone.

CONCLUSION

In view of the inflammatory events associated with some cases of ectopic pregnancies, elevated levels of anticardiolipin auto-antibodies may give clues to pathogenesis. Determination of IgM antibodies may help discriminate ectopic pregnancies with auto-immune pathogenesis from those caused by other factors.

Antiphospholipid syndrome and recurrent miscarriages

Sixty percent of recurrent spontaneous abortions are unexplained. Antiphospholipid syndrome is a multisystem disease with the predominant features of venous and arterial thrombosis, recurrent pregnancy loss, foetal death and the presence of antiphospholipid antibodies. Many epidemiological studies focus on antiphospholipid autoantibodies syndrome (APS) as a cause of recurrent spontaneous abortion (RSA). It is found that 7-25% of RSA would have APS as the main risk factor. 'Association not being synonymous with cause', the proportion of abortions due to the APS is difficult to estimate for several reasons: definition of recurrent abortion is variable, the assays for antiphospholipid antibodies are not well standardised, inclusion of patients in the study group according to the antibodies titre is author dependent. Recent studies suggest association of antiphospholipid antibodies syndrome not only with recurrent abortions but also with infertility. New mechanisms are described by which antiphospholipid antibodies could cause placental thrombosis and infarction, acting directly on the surface anticoagulant expressed on trophoblastic cells. Only lupus anticoagulant (LA) and anticardiolipin antibodies (aCL) assays are sufficiently standardised to be usable in routine. Testing for other antiphospholipid antibodies (aPLs) should remain investigational. Several treatments have been proposed: low doses of aspirin, low or immunosuppressive doses of corticosteroids, and preventive or effective dose of heparin, intravenous immunoglobulin.

Antibodies to phosphatidylethanolamine and phosphatidylserine are associated with increased natural killer cell activity in non-male factor infertility patients

Antiphospholipid antibodies (APA) have been identified in patients with recurrent pregnancy loss and IVF failure. Of these, antiphosphatidylethanolamine (aPE) and antiphosphatidylserine (aPS) may have special significance. A link between increased natural killer cell activity (NKa+) and trophoblast cell apoptosis has also been reported. This study was undertaken to determine how the APA profile was associated with peripheral NK cell activity. We evaluated 197 female IVF candidates for APA and NKa. Eighty-nine patients (45%) were APA+ and of these, 51 (57%) were aPE/aPS+. Fifty-four patients (27%) had increased NK cell activity. Some 51% of APA+ and 78% of aPE/aPS+ patients had increased NK cell activity compared with 8% and 13% when APA and aPE/aPS tested negative respectively (P: < 0.0001). Non-male factor infertility patients were APA+ and NKa+ in 57% and 34% of cases respectively, compared with 19% and 13% if a pure male factor was present. Some 88% of aPE/aPS+, non-male factor patients had increased NK cell activity, compared with 12% who tested aPE/aPS negative (P: < 0.0001) and 25% of aPE/aPS+, isolated male factor patients (P: < 0.0001). These findings establish a direct relationship between APA (specifically aPE/aPS) and increased peripheral NK cell activity among non-male factor infertility patients. It is possible that APA do not directly cause reproductive failure but rather function as markers or intermediaries for an underlying, abnormal activation of cellular immunity.

Immunodiagnostic evaluation in women with reproductive failure

PROBLEM

Several immunological factors have been associated with diagnostic subpopulations of reproductive failure. It is important to determine a trend of immunological abnormalities among these subpopulations. The purpose of this study is to assist in the selection of treatment for patients suspected of having specific diagnoses of reproductive failure.

METHOD OF STUDY

Blood samples from 591 patients were evaluated for the presence of antiphospholipid (APA), antinuclear (ANA), and antithyroid (ATA) antibodies, as well as for lupus anticoagulant (LA), embryotoxic factors (ETF), and elevated levels of natural killer (NK) (CD56+) cells, and all tests were performed as a panel. The patients were grouped into the following diagnostic categories: recurrent pregnancy loss (n = 302), IVF/ET failure (IVFf, n = 122), unexplained infertility (n = 97), ovarian dysfunction (n = 47), and endometriosis (n = 23). The thresholds for positivity and the prevalence of the tested factors among normal healthy populations have been established by testing 100 or more healthy male and female individuals with each one of the tests used (general population control). All tests as panel were performed on 20 normal fertile female individuals as controls (fertile female controls).

RESULTS

Of all patients with reproductive failure, 75.6% had at least one abnormal test. The most frequent abnormal result was found to be the elevation of NK (CD56+) cells (37%), followed by ANA (34%), APA (24%), ATA (19%), and ETF (11%). Of the recurrent pregnancy loss patients, 74.2% had at least one positive abnormal result from all of the tests performed: overall, 70% of women with IVF failure had at least one abnormal test; of patients diagnosed with unexplained infertility, approximately 81% had at least one abnormal result; 74.4% of the patients with ovarian dysfunction and 52% of the patients with endometriosis had at least one abnormal result. From normal fertile controls, 10% showed at least one abnormal test result.

CONCLUSION

APA, ANA, ATA, ETF, and elevated NK (CD56 ) cells are significantly more prevalent among women experiencing reproductive failure than among the control group and normal healthy individuals.

Murine embryos as a direct target for some human autoantibodies in vitro

The involvement of one or another autoantibody in reproductive failure have long been thought to be through post-implantation thrombosis and/or peri-implantation trophoblast dysfunction and/or maternal hormonal imbalance. It can be postulated that the embryo may be a direct target for some autoantibodies prior to implantation. Mouse embryos have been labelled and cultured with affinity purified immunoglobulin (IgG) and IgA from positive for antiphospholipid antibody sera, as well as IgG from positive for antinuclear antibody sera and positive for antithyroid antibody sera. Intact IgG and IgA from healthy individuals were used as controls. All embryos cultured with purified antiphospholipid IgG or IgA, and anti-nuclear IgG exhibited strong immunofluorescence. No difference in fluorescent intensity was observed whether antiphospholipid or anti-nuclear antibodies were used, but the pattern of antibody distribution seemed to be different. Antiphospholipid IgG was more dominant on the zona pellucida, while antiphospholipid IgA and antinuclear IgG had predominant distribution on the embryonic cells. None of the embryos cultured with antithyroid IgG or with control immunoglobulins showed strong immunofluorescence. Embryos cultured with purified antiphospholipid and antinuclear immunoglobulins experienced significant growth impairment or death compared to those cultured with antithyroid or control immunoglobulins.

Heparin plus aspirin as a "single" therapy for recurrent spontaneous abortion associated with both allo- and autoimmunity

PROBLEM

The aim of this study was to contribute to the study of the pathogenesis and the treatment of recurrent spontaneous abortion (RSA) associated with immune alterations.

METHOD OF STUDY

This is a prospective clinical trial with 11 patients with RSA associated with allo- and autoimmunity not receiving lymphocyte immunizations but only heparin and aspirin preconceptionally and through pregnancy. A concurrent group of 8 patients receiving a complete therapy (lymphocyte immunizations, heparin, and aspirin) but not receiving heparin and aspirin preconceptionally is also included in this report.

RESULTS

The rate of pregnancy success in these patients was 90.9% (10/11), and the rate of success of the concurrent group was 75.0% (6/8).

CONCLUSIONS

The results are in agreement with the working hypothesis regarding the possible final common mechanism in the pathogenesis of abortion associated with allo- and autoimmunity. The "single" therapy with heparin and aspirin was effective, less costly, and logistically simpler to provide than a complete therapy including lymphocyte immunizations.

Antiphospholipid antibodies associated with implantation failure after IVF/ET

PURPOSE

Our purpose was to determine the specific antiphospholipid antibodies (APAs) that should be evaluated to identify individuals at risk for implantation failure associated with reproductive autoimmune failure syndrome (RAFS).

METHODS

The prevalence of APAs among 312 women with implantation failure was compared with that of 100 fertile control women. To be included in the implantation failure group, each woman had to have had at least 12 embryos transferred without subsequent positive pregnancy test. Enzyme-linked immunoabsorbant assay was used to measure IgG, IgM, and IgA anticardiolipin, antiphosphatidyl ethanolamine, antiphosphatidyl inositol, antiphospatidic acid, anti-phosphatidyl glycerol, antiphosphatidyl choline, and antiphosphatidyl serine.

RESULTS

When the values for each of the seven APAs in three isotypes were compared between women with implantation failure and the control population, all of the APAs tested had a significantly higher frequency among women with implantation failure. Positive APAs were detected in 69 (22%) of the 312 women with implantation failure compared with 5 (5%) of the 100 control women (P < 0.0001). Anticardiolipin antibodies were found in 13 (4%) of the 312 women with implantation failure and none of the controls. Fifty-six (18%) of the 312 with implantation failure were negative for anticardiolipin antibodies but had positive values of other APAs.

CONCLUSIONS

A complete APA panel using seven isotypes is necessary for diagnosing implantation failure associated with RAFS. If only anticardiolipin antibody is measured, 4% (13/312) of the positive APAs are detected, and 81% (56/69) of women with implantation failure associated with RAFS will have the diagnosis missed.