Anti-cardiolipin antibodies induce pregnancy failure by impairing embryonic implantation

A retrospective study on IVF/ICSI outcomes in patients with persisted positive of anticardiolipin antibody: Effects of low-dose aspirin plus low molecular weight heparin adjuvant treatment

Antiphospholipid (aPL) antibodies are more frequently detected among infertile women, but the association between aPL and in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) outcomes and whether need to get routine treatment are still controversial. The present study aims to find out whether infertile population with persistent aPL positive need treatment and which therapy is more effective. This retrospective study included 181 persistent aPL positive women, including 149 cases receiving anticoagulant treatment, either low-dose aspirin, low molecular weight heparin (LMWH) or aspirin plus LMWH adjuvant treatment (treated group), and 32 cases not receiving any treatment (untreated group). The treated group were further divided by combination therapy group (using both aspirin and LMWH，52 cases) and monotherapy group (only using aspirin，76 cases). The live birth rate and other clinical outcomes, including pregnancy rate, implantation rate, ongoing pregnancy rate and miscarriage rate were compared. The results show anticoagulant therapy can significantly improve live birth rate (59.06 % VS 34.48 %, P = 0.019), implantation rate (59.64 % VS 46.15 %, P＜0.001), ongoing pregnancy rate (59.73 % VS 34.38 %, P = 0.016), as well as reduce miscarriage rate (8.25 % VS 31.25 %, P＜0.001). Combination treatment of aspirin and LMWH exerts a higher live birth rate than monotherapy (75.00 % VS 53.95 %, P = 0.026). Infertile women with aPL positive might be classified as high-risk and low-risk aPL profiles. Those high-risk aPL positive infertile populations should be identified during IVF/ICSI and given corresponding thromboprophylaxis, and aspirin plus LMWH adjuvant treatment might be recommended.

Correlation Between the Presence of Antinuclear Antibodies and Recurrent Pregnancy Loss: A Mini Review

In the past decade, the incidence of recurrent pregnancy loss (RPL) has increased significantly, and immunological disorders have been considered as one of the possible causes contributing to RPL. The presence of antinuclear antibodies (ANAs) is regarded as a typical antibody of autoimmunity. However, the relationship between the presence of ANAs and RPL, the underlying mechanism, and the possible role of immunotherapy is still controversial. The aim of this mini review is to assess the association between ANAs and RPL and the effects of immunotherapy on pregnancy outcomes in women with positive ANAs and a history of RPL from the available data and to provide a relevant reference basis for clinical application in this group of women.

The antiphospholipid syndrome - often overlooked cause of vascular occlusions?

The antiphospholipid syndrome (APS) was fully recognized as a clinical entity in the early 1980s. Still, more than 30 years later, the epidemiology of APS is not well described, and furthermore, APS remains a challenge in terms of both diagnostic issues and clinical praxis involving a wide range of specialties. To date, there are no diagnostic criteria for APS. The present classification criteria rely on a combination of clinical manifestations and persistently positive tests for antiphospholipid antibodies (aPL). Clinical symptoms comprise vascular thrombosis, which can affect any vascular bed, including venous, microvascular and arterial vessels, and a set of pregnancy morbidities including early and late miscarriages, foetal death and preeclampsia. APS is more frequent among patients with other autoimmune diseases, and it is especially common in systemic lupus erythematosus (SLE). Importantly, APS symptoms can present in almost any medical specialty, but general knowledge and most previous clinical studies have essentially been confined to haematology, rheumatology and obstetrics/gynaecology. However, recent data demonstrate a relatively high prevalence of aPL also in patients from the general population who suffer from vascular occlusions or pregnancy complications. It is important that these patients are recognized by the general health care since APS is a treatable condition. This review aims to summarize the present knowledge on the history, pathogenesis, clinical manifestations and treatment of APS in order to urge a wide range of clinicians to consider comprehensive assessment of all patients where the diagnosis APS may be conceivable.

Multitrait meta-analysis identified genomic regions associated with sexual precocity in tropical beef cattle

Multitrait meta-analyses are a strategy to produce more accurate genome-wide association studies, especially for complex phenotypes. We carried out a meta-analysis study for traits related to sexual precocity in tropical beef cattle (Nellore and Brahman) aiming to identify important genomic regions affecting these traits. The traits included in the analyses were age at first calving (AFC), early pregnancy (EP), age at first corpus luteum (AGECL), first postpartum anoestrus interval (PPAI), and scrotal circumference (SC). The traits AFC, EP, and SCN were measured in Nellore cattle, while AGECL, PPAI, and SCB were measured in Brahman cattle. Meta-analysis resulted in 108 significant single-nucleotide polymorphisms (SNPs), at an empirical threshold P-value of 1.39 × 10-5 (false discovery rate [FDR] < 0.05). Within 0.5 Mb of the significant SNP, candidate genes were annotated and analyzed for functional enrichment. Most of the closest genes to the SNP with higher significance in each chromosome have been associated with important roles in reproductive function. They are TSC22D2, KLF7, ARHGAP29, 7SK, MAP3K5, TLE3, WDR5, TAF3, TMEM68, PPP1R15B, NR2F2, GALR1, SUFU, and KCNU1. We did not observe any significant SNP in BTA5, BTA12, BTA17, BTA18, BTA19, BTA20, BTA22, BTA23, BTA25, and BTA28. Although the majority of significant SNPs are in BTA14, it was identified significant associations in multiple chromosomes (19 out of 29 autosomes), which is consistent with the postulation that reproductive traits are complex polygenic phenotypes. Five proposed association regions harbor the majority of the significant SNP (76%) and were distributed over four chromosomes (P < 1.39 × 10-5, FDR < 0.05): BTA2 (5.55%) from 95 to 96 Mb, BTA4 (5.55%) from 94.1 to 94.8 Mb, BTA14 (59.26%) from 24 to 25 Mb and 29 to 30 Mb, and BTA21 (5.55%) from 6.7 Mb to 11.4 Mb. These regions harbored key genes related to reproductive function. Moreover, these genes were enriched for functional groups associated with immune response, maternal-fetal tolerance, pregnancy maintenance, embryo development, fertility, and response to stress. Further studies including other breeds and precocity traits could confirm the importance of these regions and identify new candidate regions for sexual precocity in beef cattle.

Relationship Between Fetal Loss and Serum Gonadal Hormones Level in Experimental Antiphospholipid Syndrome Mouse

To investigate the effects of antiphospholipid antibodies on establishment of pregnancy and changes in hormones such as estradiol-17ß (E2) and progesterone (P) levels in circulation. Hence, mice were immunized with human β2-Glycoprotein I (β2GPI) and the effect of these antibodies on fetuses weight, placental obsrvation, Serum levels of P and E2 in pregnant mice, hematological were observed. Immunization of mice with human β2-GPI resulted in elevated levels of antiphospholipid antibodies. The experimentally induced antiphospholipid syndrome mouse showed higher rate of fetal resorption, low number of viable fetuses, and "placental abnormalities". In these animals, serum E2 and P levels were reduced significantly. In addition, the blood cell variation among APS induced and control mice were determined. No significant variations were observed in number of Red Blood Cell count, White Blood Cell count and Hemoglobin content, while platelet number was significantly reduced as compared to control. These results clearly demonstrate that human β2-GPI might be involved in causing gestational failure in APS by exerting their effect on serum hormones.

Antiphospholipid antibodies as cause of pregnancy loss

Antiphospholipid antibodies detected by lupus anticoagulant, anticardiolipin or anti-beta2 glycoprotein I assays were associated with fetal loss. Rather than being diagnostic tools only, antiphospholipid antibodies are thought to be pathogenic. The strongest demonstration of their pathogenic role lies in the ability to induce fetal resorptions - the experimental equivalents of the human fetal losses - when passively infused in pregnant naive animals. However, still debated is how the antibodies might induce the obstetrical manifestations. Thrombotic events at the placental levels might be related to endothelial cell activation, inhibition of protein C/S system and fibrinolysis as well as to Annexin V displacement. However, the thrombophilic state apparently cannot explain all the miscarriages and a direct antibody-mediated damage on the trophoblast has been suggested. During differentiation to syncytium, trophoblasts express cell membrane anionic phospholipids that can bind beta2 glycoprotein I, the main cationic phospholipid binding protein recognized by the antiphospholipid antibodies. Adhered b2-glycoprotein I might be recognized by the antibodies that, once bound, strongly interfere with in vitro trophoblast cell maturation so resulting in a defective placentation. These mechanisms have been suggested to play a role in early fetal loss, while thrombotic events would be responsible for miscarriages late in the pregnancy.

IVIG in APS pregnancy

For more than two decades, the intravenous administration of high doses of IgG pooled from the plasma of healthy donors (immune globulin therapy, also known as ‘IVIG’) has benefited patients with a variety of autoimmune disorders. A potential therapeutic role of IVIG in the prevention of thrombosis and of miscarriages in antiphospholipid syndrome (APS) has been postulated. Multicenter randomized controlled trials attempted to define the role of IVIG in preventing pregnancy complications in APS indicate that simple anticoagulation could not be completely satisfactory, and certain patient subgroups might take advantage of IVIG therapy alone or in combination with heparin.

The role of antiphospholipid antibodies (aPls) in infertile women: the long-lasting experience

Antiphospholipid antibodies (aPls) are generally characterized as heterogeneous and non-specific autoantibodies directed against various phospholipids such as cardiolipin, ph-serine, ph-inositol, ph-acid, ph-glycerol, ph-sphyngomyelin, ph-choline, annexins, and co-factor β2-glycoprotein I. aPls occur not only during autoimmune diseases but also during infectious diseases, essential hypertension, neurological complication, metabolic diseases, some drug abuse, and transplant loss. aPls are very often found in connection with reproductive failure such as repeated pregnancy loss and/or missed abortion, intrauterine fetal death, in preeclampsia, and repeated delivery of hypothrophic fetus. The presence of aPls, thrombosis, and fertility failure create primary or secondary antiphospholipid syndrome. This article explains some aspects and clinical and laboratory significance of the aPls in female infertility.

Antiphospholipid antibodies and the placenta: a systematic review of their in vitro effects and modulation by treatment

BACKGROUND

Antiphospholipid antibodies (aPL) are a family of auto-antibodies that are associated with an increased risk of recurrent miscarriage, intrauterine growth restriction and preterm birth. The placenta is a major target of aPL and it is likely that these antibodies promote pregnancy morbidity by affecting trophoblast function. Numerous studies have investigated the effect of aPL on trophoblast function in vitro. However, different trophoblast models and a variety of culture conditions have been employed, resulting in a myriad of different reported findings. This review systematically summarized those published studies that have investigated the effect of aPL on trophoblast function in vitro. In addition, the reported effects of pharmacological treatment on trophoblast function in the presence of aPL were also systematically reviewed.

METHODS

PubMed, Scopus, Embase and Web of Science databases were searched using the keywords 'placenta OR trophoblast' AND 'antiphospholipid antibody OR antiphospholipid syndrome' up to 25 April 2014. Studies were excluded based on the absence of appropriate controls. The effects of aPL on trophoblast proliferation, death, syncytialization, invasion, hormone production, cytokine production, coagulation and complement activation were recorded. The effects of different treatments on the function of trophoblasts in the presence of aPL were also recorded.

RESULTS

A total of 1071 records were retrieved from the four databases. After removing duplicates, the titles and abstracts of 529 articles were reviewed. Of those, 48 articles were read and relevant experimental results were extracted from 47 articles.

CONCLUSIONS

This systematic review provides an overview of all the studies performed to date on the effects of aPL on trophoblast function in vitro. There is considerable support for aPL decreasing trophoblast viability, syncytialization and invasion in vitro. Some work has also suggested that aPL may affect the production of hormones and signalling molecules by trophoblasts, and may stimulate coagulation and complement activation in vitro. Current reports of the in vitro effects of therapeutic treatments on trophoblast function in the presence of aPL are inconclusive. This systematic review has highlighted many gaps in our knowledge of how aPL work and may direct future research in this area.

Pregnancy and thrombophilia

The physiological changes that occur during pregnancy create a hypercoagulable milieu. This hypercoagulable state is thought to be protective, especially at the time of labor, preventing excessive hemorrhage. The presence of hereditary or acquired causes of thrombophilia during pregnancy tilts the balance in favor of unwanted venous thromboembolism and adverse pregnancy outcomes due to vascular uteroplacental insufficiency. These adverse pregnancy outcomes include recurrent pregnancy losses, intrauterine fetal death, intrauterine growth retardation, preeclampsia and placental abruption. Much of the current data with regards to the association of the different thrombophilias and pregnancy-related complications are based on retrospectively designed studies. This lack of randomization, in-homogeneity of patient populations, varying case definitions, selection biases and inadequately matched control populations, have given rise to conflicting data with regard to screening for, and treatment of, pregnant women with suspected thrombophilias. The limited data that we have support the use of anticoagulant drugs for the prevention of pregnancy-related complications in the setting of thrombophilia. Heparin and low-molecular-weight heparins are the anticoagulant drugs of choice as they do not cross the placental barrier and, hence, do not cause fetal anticoagulation or teratogenicity. Warfarin can be used from the 12th week of gestation onwards but is preferably reserved for the postpartum period.

Management of women with recurrent pregnancy losses and antiphospholipid antibody syndrome

Antiphospholipid antibodies (aPL) have been associated with recurrent pregnancy losses (RPL) and other obstetrical complications. The diagnostic criteria for the classical antiphospholipid antibody syndrome (APS) have been utilized for the detection of obstetrical APS in women with RPL. However, laboratory findings and immunopathology of obstetrical APS are significantly different from those of classical APS. In addition, many women with RPL who have positive aPL do not have symptoms consistent with the current APS criteria. The induction of a proinflammatory immune response from trophoblasts and complement activation by aPL rather than thromboembolic changes has been reported as a major immunopathological feature of obstetrical APS. Heparin treatment has been reported to be effective in prevention of early pregnancy loss with APS but not for the late pregnancy loss or complications. The complex effects of heparin may explain the limited efficacy of heparin treatment in RPL. New diagnostic criteria for obstetrical APS are needed urgently, and new therapeutic approaches should be explored further.

Impact of anticardiolipin antibody on the outcome of in vitro fertilization and embryo transfer

PROBLEM

To investigate the impact of anticardiolipin antibody (ACA) on the outcome of in vitro fertilization and embryo transfer (IVF-ET).

METHODS

A total of 76 infertile women positive for anticardiolipin antibody (ACA+ group) and 819 controls negative for anticardiolipin antibody (ACA- group) undergoing IVF-ET in the First Affiliated Hospital, to Sun Yat-Sen University, were retrospectively analyzed. Women were diagnosed as having pure tubal factor infertility.

RESULTS

The proportion of patients with a history of spontaneous abortion in the ACA+ group was significantly higher than that in ACA- group (19.7% versus 8.9%). The IVF rate, pregnancy rate and implantation rate in the ACA+ group were markedly lower than those in the ACA- group (75.5% versus 78.9%, 31.3% versus 48.6% and 16.1% versus 28.1%, respectively). Furthermore, the incidence of pregnancy loss in the ACA+ group was higher than that in the ACA- group (32.0% versus 15.1%).

CONCLUSION

ACA-positive patients had significantly decreased IVF rate, pregnancy rate and implantation rate and high risk of abortion. Therefore, ACA positivity predicts poor outcome of IVF-ET, and pre-treatment to lower ACA level may be clinically beneficial for patients receiving IVF-ET.

Induction of APS after TTd hyper-immunization has a different outcome in BALB/c and C57BL/6 mice

PROBLEM

The antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by vascular thrombosis and/or pregnancy complications (lower fecundity and lower litter size), as well as by an increase in anti-β(2) glycoprotein I (β(2) GPI)-specific autoantibody titer. We have investigated how the genetic background of the immune system [T helper (Th) prevalence] and the type of animal model of APS influence the induced pathology.

METHOD OF STUDY

Antiphospholipid syndrome induced by tetanus toxoid (TTd) hyper-immunization and by intravenous application of monoclonal anti-β(2) GPI-specific antibody 26 was compared in C57BL/6 (Th1 prone) and BALB/c (Th2 prone) mice.

RESULTS

Tetanus toxoid hyper-immunization of BALB/c mice led to reduction in fertility, but in C57BL/6 mice a decrease in fecundity occurred. In both cases, pathology was caused by anti-β(2) GPI antibodies, the production of which was adjuvant and strain dependent.

CONCLUSION

We conclude that TTd immunization and i.v. application of monoclonal antibody 26 induced the same reproductive pathology and that the type of pathology is strain dependent.

Antiphospholipid antibody-mediated reproductive failure in antiphospholipid syndrome

The association of elevated titers of circulating antiphospholipid (anti-PL) Abs in antiphospholipid syndrome (APS) and reproductive failure is well established in the literature. The clinical features include recurrent abortions at various stages, including implantation, placentation in the first trimester, miscarriages in the second and third trimesters, intrauterine growth retardation, preeclampsia with placental insufficiency and growth restrictions, arterial and venous thrombosis, and possibly also infertility. APS-mediated recurrent pregnancy loss and other features of reproductive failure might result from diverse autoimmune factors, inflammation, involving different mechanisms, which encompass pathogenic anti-PL Abs. Herein, we discuss the association of anti-PL Abs with reproductive failure with special emphasis on antiphospholipid autoantibodies characterizing APS. This association is evident from either human studies or murine models.

Consultative hematology: the pregnant patient pregnancy loss

The presence of antiphospholipid antibodies has been associated with an increased risk of recurrent pregnancy loss, and there is evidence to suggest that antithrombotic therapy improves the likelihood of a successful outcome in affected women. Recent studies suggest an association between hereditary thrombophilia and pregnancy loss, although a causal role remains controversial. Although the available data are limited and flawed, there is increasing use of antithrombotic therapy in thrombophilic women with a history of pregnancy failure. Given the absence of proven effective therapy in women with unexplained recurrent loss, there is also growing pressure to intervene with antithrombotics in women with no known underlying thrombophilia. This article reviews the evidence for an association between thrombophilia and recurrent pregnancy loss and the data regarding the use of antithrombotic therapy for prevention of loss-an area that remains particularly challenging because of the paucity of good quality data upon which to base clinical decisions.

Updating on the pathogenic mechanisms 5 of the antiphospholipid antibodies-associated pregnancy loss

Anti-phospholipid antibodies (aPL) are risk factor for recurrent pregnancy loss and obstetrical complications. The mechanisms of aPL-mediated pregnancy failure are still a matter of research. Although aPL are associated with thrombosis, thrombotic events cannot explain all the miscarriages. There is evidence for a direct in vitro aPL effect on the trophoblast as shown by their binding; reduction of proliferation, human chorionic gonadotrophin release, in vitro invasiveness, adhesion molecule expression; and increased apoptosis. Such a direct reactivity is supported by the expression of beta2 glycoprotein (beta 2GP) I on trophoblast cell membranes. aPL/anti-beta 2GPI antibodies also bind to human decidual/endometrial cells in vitro and induce a pro-inflammatory phenotype. APL-mediated inflammatory processes at the placental level are apparently responsible for fetal loss at least in animal models. Both complement activation and pro-inflammatory cytokine/chemokine secretion have been shown to play a role. More recently, complement-induced tissue factor expression on infiltrating neutrophils was described as an additional pathogenic mechanisms mediated by aPL. As a whole, these findings do suggest that aPL may induce a defective placentation by acting at different levels without involving necessarily thrombotic events.

Venous thromboembolism, thrombophilia, antithrombotic therapy, and pregnancy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)

This article discusses the management of venous thromboembolism (VTE) and thrombophilia, as well as the use of antithrombotic agents, during pregnancy and is part of the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Grade 1 recommendations are strong and indicate that benefits do, or do not, outweigh risks, burden, and costs. Grade 2 recommendations are weaker and imply that the magnitude of the benefits and risks, burden, and costs are less certain. Support for recommendations may come from high-quality, moderate-quality or low-quality studies; labeled, respectively, A, B, and C. Among the key recommendations in this chapter are the following: for pregnant women, in general, we recommend that vitamin K antagonists should be substituted with unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) [Grade 1A], except perhaps in women with mechanical heart valves. For pregnant patients, we suggest LMWH over UFH for the prevention and treatment of VTE (Grade 2C). For pregnant women with acute VTE, we recommend that subcutaneous LMWH or UFH should be continued throughout pregnancy (Grade 1B) and suggest that anticoagulants should be continued for at least 6 weeks postpartum (for a total minimum duration of therapy of 6 months) [Grade 2C]. For pregnant patients with a single prior episode of VTE associated with a transient risk factor that is no longer present and no thrombophilia, we recommend clinical surveillance antepartum and anticoagulant prophylaxis postpartum (Grade 1C). For other pregnant women with a history of a single prior episode of VTE who are not receiving long-term anticoagulant therapy, we recommend one of the following, rather than routine care or full-dose anticoagulation: antepartum prophylactic LMWH/UFH or intermediate-dose LMWH/UFH or clinical surveillance throughout pregnancy plus postpartum anticoagulants (Grade 1C). For such patients with a higher risk thrombophilia, in addition to postpartum prophylaxis, we suggest antepartum prophylactic or intermediate-dose LMWH or prophylactic or intermediate-dose UFH, rather than clinical surveillance (Grade 2C). We suggest that pregnant women with multiple episodes of VTE who are not receiving long-term anticoagulants receive antepartum prophylactic, intermediate-dose, or adjusted-dose LMWH or intermediate or adjusted-dose UFH, followed by postpartum anticoagulants (Grade 2C). For those pregnant women with prior VTE who are receiving long-term anticoagulants, we recommend LMWH or UFH throughout pregnancy (either adjusted-dose LMWH or UFH, 75% of adjusted-dose LMWH, or intermediate-dose LMWH) followed by resumption of long-term anticoagulants postpartum (Grade 1C). We suggest both antepartum and postpartum prophylaxis for pregnant women with no prior history of VTE but antithrombin deficiency (Grade 2C). For all other pregnant women with thrombophilia but no prior VTE, we suggest antepartum clinical surveillance or prophylactic LMWH or UFH, plus postpartum anticoagulants, rather than routine care (Grade 2C). For women with recurrent early pregnancy loss or unexplained late pregnancy loss, we recommend screening for antiphospholipid antibodies (APLAs) [Grade 1A]. For women with these pregnancy complications who test positive for APLAs and have no history of venous or arterial thrombosis, we recommend antepartum administration of prophylactic or intermediate-dose UFH or prophylactic LMWH combined with aspirin (Grade 1B). We recommend that the decision about anticoagulant management during pregnancy for pregnant women with mechanical heart valves include an assessment of additional risk factors for thromboembolism including valve type, position, and history of thromboembolism (Grade 1C). While patient values and preferences are important for all decisions regarding antithrombotic therapy in pregnancy, this is particularly so for women with mechanical heart valves. For these women, we recommend either adjusted-dose bid LMWH throughout pregnancy (Grade 1C), adjusted-dose UFH throughout pregnancy (Grade 1C), or one of these two regimens until the thirteenth week with warfarin substitution until close to delivery before restarting LMWH or UFH) [Grade 1C]. However, if a pregnant woman with a mechanical heart valve is judged to be at very high risk of thromboembolism and there are concerns about the efficacy and safety of LMWH or UFH as dosed above, we suggest vitamin K antagonists throughout pregnancy with replacement by UFH or LMWH close to delivery, after a thorough discussion of the potential risks and benefits of this approach (Grade 2C).

Early risk factors for miscarriage: a prospective cohort study in pregnant women

Many pregnancies are lost during early gestation, but clinicians still lack tools to recognize risk factors for miscarriage. Thus, the identification of risk factors for miscarriage during the first trimester in women with no obvious risk for a pregnancy loss was the aim of this prospective cohort trial. A total of 1098 women between gestation weeks 4 and 12 in whom no apparent signs of a threatened pregnancy could be diagnosed were recruited. Demographic, anamnestic, psychometric and biological data were documented at recruitment and pregnancy outcomes were registered subsequently. Among the cases with sufficiently available data, 809 successfully progressing pregnancies and 55 subsequent miscarriages were reported. In this cohort, risk of miscarriage was significantly increased in women at higher age (>33 years), lower body mass index (< or =20 kg/ m(2)) and lower serum progesterone concentrations (< or =12 ng/ml) prior to the onset of the miscarriage. Women with subsequent miscarriage also perceived higher levels of stress/demands (supported by higher concentrations of corticotrophin-releasing hormone) and revealed reduced concentrations of progesterone-induced blocking factor. These risk factors were even more pronounced in the subcohort of women (n = 335) recruited between gestation weeks 4 and 7. The identification of these risk factors and development of an interaction model of these factors, as introduced in this article, will help clinicians to recognize pregnant women who require extra monitoring and who might benefit from therapeutic interventions such as progestogen supplementation, especially during the first weeks of pregnancy, to prevent a miscarriage.

Antiphospholipid antibodies: laboratory and pathogenetic aspects

Antiphospholipid antibodies (aPL) constitute a heterogeneous group of autoantibodies that share the ability to bind phospholipids (PL) alone, protein-PL complexes, or PL-binding proteins. They have been detected in isolation, in association with autoimmune diseases such as systemic lupus erythematosus (SLE), and during the course of different infections. aPL have been associated with an array of clinical manifestations in virtually every organ, although deep vein and arterial thrombosis as well as pregnancy morbidity are predominant. The co-occurrence of these clinical findings with aPL constitutes the so-called antiphospholipid syndrome (APS). aPL can be detected by immunological methods [e.g., anticardiolipin antibodies (aCL)] or by functional methods that exploit the effect of aPL on blood coagulation [lupus anticoagulant (LA)]. Since aPL are heterogeneous, numerous immunological and coagulation assays have been developed. These assays have not been fully standardized, and, therefore, problems such as high interlaboratory variation are relatively frequent. Recently, recommendations have been published regarding LA and aCL testing. Not all aPL are pathogenic. However, when they are not associated with infections, they have a role in the pathogenesis of APS. Clinical and experimental data have shown that aPL exert their pathogenic activity by interfering with the function of coagulation factors, such as thrombin and factors X, XI and XII, and with the function of anticoagulant proteins of the protein C system. In addition, aPL interaction with platelets and endothelial cells induces a pro-adhesive activated phenotype.

Role of anti-β2 glycoprotein I antibodies in antiphospholipid syndromeglycoprotein I antibodies in antiphospholipid syndrome

Antiphospholipid syndrome (APS) is characterized by the presence of recurrent venous/ arterial thrombosis and fetal losses associated with a family of auto-antibodies directed against phospholipid (PL)-binding proteins. Among them, beta2 glycoprotein I (beta2GPI) is the most important. As a plasma cationic protein, beta2GPI binds to anionic PLs involved in several fluid-phase coagulation steps, and more importantly, it can be expressed on the surface of different cell types. Anti-beta2GPI antibodies recognize the molecule expressed on endothelial cells, platelets, monocytes, and trophoblast cells. Once bound, the antibodies trigger in vitro cell signaling that modulates biological responses potentially responsible for pathogenic mechanisms. Experimental animal models have supported the in vivo pathogenic role of anti-beta2GPI antibodies in both thrombosis and fetal loss models.

IgG-antiphospholipid antibodies in follicular fluid of IVF-ET patients are related to low fertilization rate of their oocytes

PROBLEM

Patients undergoing in vitro fertilization and embryo transfer (IVF-ET) failures show an increased incidence of antiphospholipid antibodies (aPL) in their blood. The physiological manifestations of aPL in this patient group are nonetheless controversial. Pathological effects of aPL on embryos in vitro have been documented. We questioned whether aPL if found in follicular fluids (FFs) could result in embryonic damage.

METHOD OF STUDY

Blood from 44 patients with three or more IVF-ET failures were tested by enzyme-linked immunosorbent assays (ELISA) for the presence of immunoglobulin (Ig)G, IgM and IgA aPL. Both the 29 aPL-positive and 15 aPL-negative patients gave permission for FF collection during their next IVF-ET attempt for additional aPL determinations.

RESULTS

Patients with no aPL in their blood, had no aPL in their FFs. Patients with IgG and/or IgM aPL in their blood had IgG but not IgM in their respective FFs.

CONCLUSIONS

The presence of IgG aPL in FFs and increased infertility length were significantly related to lower fertilization rates, independently. Follicular fluid IgG aPL appears as a risk factor in association with successful IVF-ET outcomes.

Autoantibodies in Argentine women with recurrent pregnancy loss

PROBLEM

To determine the presence or absence of subclinical autoimmunity in Caucasian Argentine healthy women with first trimester recurrent pregnancy loss (RPL), the sera of 118 healthy women with a history of three or more consecutive abortions and 125 fertile control women without abortions and two children were analyzed for the presence of autoantibodies: immunoglobulin (Ig)G and IgM anticardiolipin, antinuclear (ANA), antismooth muscle (ASMA), antimitocondrial (AMA), antiliver-kidney-microsomal fraction (LKM), antigastric parietal cells (GPC), antineutrophil cytoplasmatic (ANCA) and antibodies antigliadin type IgA and IgG and IgA antitransglutaminase related with celiac disease (CD).

METHOD OF STUDY

ANA, ASMA, AMA, anti-LKM, antibodies to GPC and ANCA were determined by indirect immunofluorescence (IFI) and anticardiolipin, antigliadina and antitransglutaminase antibodies were measured by enzyme-linked immunosorbent assays (ELISA).

RESULTS

There was no significant difference between controls and patients with ANA, ASMA, AMA, LKM, ANCA and GPC. The prevalence of anticardiolipin antibodies in RPL was significantly higher than controls (P < 0,01) and the prevalence of positive antibodies for antigliadina type IgA and IgG and IgA antitransglutaminase in RPL was significantly higher than controls (P < 0.04).

CONCLUSION

We show that Caucasian Argentine women with RPL showed significantly higher incidence of anticardiolipin antibodies than normal controls and finally we recommended the screening of IgA and IgG antigliadina and IgA antitransglutaminase antibodies in pregnancy, because of the high prevalence of subclinical CD in RPL and the chance of reversibility through consumption of a gluten free diet.

Human decidua-associated protein 200 neutralizes the detrimental effect of serum containing antiphospholipid antibodies on fetal survival in the rat

PROBLEM

We wanted to examine whether the detrimental effect of serum containing antiphospholipid (APL) antibodies on rat pregnancy outcome can be neutralized by addition of human decidua-associated protein (hDP) 200, a kind of rheumatoid factor, extracted from decidual tissue.

METHODS

Fifty microliters of pooled serum, obtained from women having anticardiolipin antibody and lupus anticoagulant and presenting with APL antibody syndrome, added with 100 microL of immunoaffinity purified hDP200 was injected into unilateral uterine horn of each rat on day L5 of rat pregnancy. The contralateral uterine horn was used for injection of 50 microL APL positive serum added with physiologic saline as a control. The rats were killed on day L14, and the uterus of each rat was inspected for the presence of live and resorbed fetuses.

RESULTS

The addition of hDP200 to APL positive serum before the intrauterine injection neutralized the detrimental effect of APL serum on fetal resorption rate. Although the neutralizing effect was demonstrated following the addition of hDP200 and immediate intrauterine injection (a decrease in fetal resorption rate, P = 0.004), still the effect was more impressive following the addition of hDP200 and incubation period of 24 hr before the injection, thus causing a significant increase in the number of normal embryos and a significant decrease in fetal resorption rate (P < 0.001).

CONCLUSION

Human decidua-associated protein 200, extracted from human decidual tissue neutralizes the detrimental effect of serum containing APL antibodies in an experimental rat model. Further studies are needed to prove this finding.

Antiphospholipid antibodies and coagulation defects in women with implantation failure after IVF and recurrent miscarriage

Evaluation of patients with IVF implantation failure or recurrent miscarriage often frustratingly fails to elicit any particular cause for their problem. Testing for antiphospholipid antibodies or thrombophilia is commonly carried out, and interpretation of results in the light of the current evidence is extremely difficult. This paper reviews the purported pathogenetic mechanisms and clinical associations between both antiphospholipid antibodies and inherited thrombophilias, and reproductive failure. The current management strategies are also critically evaluated and recommendations are made for optimal, evidence-based clinical practice.

Antiphospholipid antibodies in serum and follicular fluid--is there a correlation with IVF implantation failure?

BACKGROUND

Antiphospholipid antibodies (aPLs) are associated with infertility, but the mechanism underlying this statistical association is currently obscure. We aimed to investigate the finding that aPLs are concentrated in follicular fluid and to establish if this is associated with a poorer outcome from IVF.

METHODS AND RESULTS

In 19.2% of 99 women undergoing IVF, at least one aPL was detected in their serum and/or follicular fluids, but the antibody levels in follicular fluid were not higher than in serum. Women with aPLs had a lower implantation rate (14%) than women without these antibodies (24.1%), but this difference was not significant (P=0.127). There was also a non-significant reduction in the live birth rate for women with aPLs. In a parallel investigation, 10 sheep immunized with beta2 glycoprotein I (beta2GPI) or irrelevant control antigens showed strong immune responses, but there were no significant differences between the levels of antibodies in the follicular fluid or serum from beta2GPI or control immunized sheep.

CONCLUSION

aPLs do not appear to be selectively concentrated in follicular fluids and, when present, do not adversely affect the reproductive outcome of women undergoing IVF.

Is previous aberrant reproductive outcome predictive of subsequently reduced fecundity?

BACKGROUND

Effect of past reproductive performance on subsequent fecundity is uncertain.

METHODS

A total of 2983 consecutive pregnant women self-completed questionnaires about time to pregnancy (TTP), pregnancy planning, previous pregnancies, contraceptive use, age, and individual/lifestyle variables. Outcome measures were: TTP, conception rates (CR) and, subfecundity odds ratio (OR; with 95% confidence intervals) before and after each outcome of last pregnancy.

RESULTS

After miscarriage, TTP was longer than before miscarriage [2.1 (1.4-3.0), P < 0.001] and than TTP after livebirth [OR = 2.1 (1.6-2.6), P < 0.001]. Also subfecundity OR after miscarriage increased [1.7 (1.2-2.4), 1.8 (1.2-2.5), P = 0.001, 0.002 respectively]. This effect was more evident in older and obese women. Compared with livebirth, time to ectopic pregnancy (EP) was longer [OR = 13.8 (1.8-108.5), P = 0.001] but TTP after EP was not significantly different. Subfecundity OR relative to livebirth were 12.8 (3.6-45.0) (P<0.001) before, and 3.9 (1.4-11.0) (P=0.01) after, EP. The CR after EP increased 3-fold (1.1-8.3) over those prior to EP. Time to the terminated pregnancies even without contraceptive failures was shorter than that to livebirth [OR = 0.5 (0.3-0.7), P = 0.001] and than TTP after termination [0.35 (0.1-0.8), P = 0.001]. Also subfecundity OR increased after termination [7.2 (1.8-29.7), P = 0.02].

CONCLUSIONS

Miscarriers should be counselled about short-term reduction in subsequent fecundity, and earlier investigations should be considered in those who have other potential risk factors for reduced fertility. Further studies are required to clarify the relatively favourable effect on fecundity following EP and the relative reduction in fecundity after termination of pregnancy.

Immunologic manipulation for the threatened fetus

Management of the pregnant woman with the antiphospholipid syndrome (APLS) has improved over the last 10 years. The recurrent pregnancy loss that is associated with this disease is managed with prophylactic low dose aspirin and heparin therapy. This therapy leads to a 40% absolute risk reduction in pregnancy loss. However, many women still fail to deliver a live infant despite this therapy so immunologic manipulation of the mother's disease in this group needs to be considered. Intravenous immunoglobulin and plasma exchange may have a role. New immunosuppressive drugs such as tacrolimus have yet to be tried. Monoclonal antibodies to B cells, B-cell growth factors, complement proteins and integrin molecules, all of which appear to play a role in the disease process, may also offer patients some hope. Similarly, biologics such as C1 esterase inhibitor protein, cell surface complement regulator proteins or interleukin-3 need to be tried given their efficacy in models of antibody-induced cell injury.

Beta-2-glycoprotein-I, infections, antiphospholipid syndrome and therapeutic considerations

Evidence supports the association between infectious agents, antiphospholipid syndrome (APS), and the presence of antiphospholipid antibodies and anti-beta2-glycoprotein-I (beta2GPI) antibodies. Several mechanisms have been proposed to explain the role of bacteria/viruses in induction of an autoimmune condition, such as molecular mimicry between structures of a pathogen and self antigen and bystander activation or bacterial/viral superantigens. Protein databases reveal high homologies between the beta2GPI-related synthetic peptides and infectious agents. Studies employing experimental APS models proved molecular mimicry between beta2GPI-related synthetic peptides, which serve as target epitopes for anti-beta2GPI Abs, and structures within bacteria, viruses (e.g., CMV), and tetanus toxoid. Any explanation of how microbial infections might induce APS must take into account the genetic predisposition. In this paper, we discuss the association of antiphospholipid antibodies, infectious states, and molecular mimicry as a proposed mechanism for development of APS.

Beta-2 glycoprotein I and its role in antiphospholipid syndrome—lessons from knockout mice

The antiphospholipid syndrome is characterized by the presence in serum of autoantibodies against beta2GPI. Although the role of beta2GPI in the pathogenesis of antiphospholipid antibody syndrome (APS) is well recognized, its exact physiological functions still remain undisclosed. Several interactions of beta2GPI with components of the coagulation cascade have been proposed, resulting in both procoagulant and anticoagulant effects. Additionally, beta2GPI has been implicated in the mechanism of recurrent fetal loss entailed in APS. Recently, using a homologous recombination approach, reproduction of mice homozygous for deletion of the beta2GPI gene has been feasible. beta2GPI knockout mice offer a valuable tool for revealing the physiological role of the protein. These mice show decreased in vitro ability for thrombin generation. Furthermore, although mice lacking beta2GPI are fertile, the success of early pregnancy is moderately compromised and functional beta2GPI is believed necessary for optimal implantation and placental morphogenesis.

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.

Beta 2 glycoprotein I-function in health and disease

Beta-2 glycoprotein I (beta2GPI) is the principal target of autoantibodies in the antiphospholipid syndrome (APS). It is abundant in human plasma and shares high homology between different mammalian species. Although the exact physiological function of beta2GPI has not been fully elucidated, several interactions have been described with other proteins and with negatively charged surfaces, such as anionic phospholipids, dextran and heparin. beta2GPI is involved in the coagulation pathway, exerting both procoagulant and anticoagulant activities. Plasma from beta2GPI-deficient mice exhibits impaired thrombin generation in vitro. Recently, it has been demonstrated that beta2GPI binds factor (F) XI in vitro at concentrations lower than those of the protein in human plasma, and this binding inhibits FXI activation to FXIa by thrombin and FXIIa. Proteolytic cleavage of the fifth domain of beta2GPI abolishes its inhibition of FXI activation and results in reduced ability of the cleaved beta2GPI to bind phospholipids. It retains its ability to bind FXI. In vivo activation of FXI by thrombin is thought to be an important mechanism by which coagulation is accelerated via components of the contact activation pathway. Thus beta2GPI may attenuate the contact activation pathway by inhibiting activation of FXI by thrombin. Moreover, because beta2GPI is the dominant autoantigen in patients with APS, dysregulation of this pathway by autoantibodies may be an important mechanism for thrombosis in patients with APS.

Antiphospholipid antibodies: discovery, definitions, detection and disease

Antiphospholipid antibodies (aPL) are immunoglobulins of IgG, IgM and IgA isotypes that target phospholipid (PL) and/or PL-binding plasma proteins. Detection of aPL in the laboratory is done currently by both immunoassays and functional coagulation tests. Convention defines aPL specificity in immunoassays according to the particular PL substrate present, for example aPS represents antiphosphatidylserine antibodies. This may be technically incorrect inasmuch as a particular PL may be responsible for binding and highly concentrating a specific plasma protein, the latter then becomes the target for the aPL. The binding of beta(2)GP-I (apolipoprotein H) to the negatively charged PL, cardiolipin (CL) provides a good example of this circumstance. In contrast, aPL which specifically prolong coagulation times in in vitro are called lupus anticoagulants (LA). The precise PL target(s) of the aPL responsible for LA activities are unknown and often debated. The persistent finding of aPL in patients in association with abnormal blood clotting and a myriad of neurological, obstetrical and rheumatic disorders often compounded by autoimmune diseases has led to an established clinical diagnosis termed antiphospholipid syndrome (APS). The common denominator for these APS patients is the presence of circulating aPL on two or more occasions and the observation of events attributable to abnormal or accelerated blood clotting somewhere in vivo. The purpose of this review is to collect, collate, and consolidate information concerning aPL.

Antiphospholipid syndrome in obstetrics

Antiphospholipid syndrome (APLS) in pregnancy is characterized by the presence of autoantibodies in association with recurrent fetal loss and severe complications such as preeclampsia, fetal growth retardation, or placental insufficiency. The most clinically important serologic markers are lupus anticoagulant, anticardiolipin antibodies, and recently anti-beta-2-glycoprotein 1 antibodies. At present, standardization does not exist and a definitive association between specific clinical manifestation and antibody level is not yet known. Experimental data gave evidence that passive transfer of antiphospholipid antibodies result in clinical manifestation of APLS, that is, fetal loss and thrombocytopenia. Treatment with heparin, aspirin, or intravenous immunoglobulins decreased the fetal loss rate. Treatment regimens in human are very difficult to interpret. Evidence from two prospective studies supported treatment with heparin and aspirin to improve pregnancy outcome. The risk of preeclampsia and placental insufficiency was substantial and occurred in 50% of patients. The general failure rate of heparin/aspirin treatment is approximately 30%. In such cases intravenous immunoglobulin in combination with heparin and aspirin has been used to treat APLS.

Beneficial effects of the anti-oestrogen tamoxifen on systemic lupus erythematosus of (NZBxNZW)F1 female mice are associated with specific reduction of IgG3 autoantibodies

BACKGROUND

Sex hormones have been shown to influence the immune system and to modify the course of autoimmune disorders.

OBJECTIVE

To examine the effects of the oestrogen antagonist tamoxifen on the course of systemic lupus erythematosus (SLE) in (NZBxNZW)F1 mice.

METHODS

Groups of 8 week old (NZBxNZW)F1 female mice were treated with tamoxifen (800 micro g/mouse; twice a week) or with double distilled water for four months. Mice were evaluated monthly for the presence of autoantibodies directed against DNA and nuclear extract (NE) by enzyme linked immunosorbent assay (ELISA). White blood cells and thrombocytes were quantified by a cell counter and proteinuria by combistix kit. At 6 months of age, all mice that did not die spontaneously were killed and evaluated for the presence of glomerular immune deposits by indirect immunofluorescence assay. IgG isotypes of autoantibodies in the mouse sera and glomeruli were determined by gamma chain specific antibodies.

RESULTS

Tamoxifen treatment significantly reduced autoantibody production directed against either NE or DNA. The latter reduction was mainly in autoantibodies of the IgG3 isotype. Furthermore, tamoxifen had significant beneficial effects on the course of SLE in (NZBxNZW)F1 mice. At 6 months of age, 40% of the untreated mice died spontaneously, whereas all the tamoxifen treated mice were still alive. All untreated mice showed severe thrombocytopenia and persistent proteinuria, with diffuse glomerular immune deposits of IgG2a and IgG3 isotypes in their kidneys. In contrast, the tamoxifen treated mice had a normal number of thrombocytes and only minimal proteinuria. Moreover, glomerular immune deposits were detected in <40% of the tamoxifen treated mice. The latter were mainly of the IgG2a but not of the IgG3 isotype.

CONCLUSION

The results clearly show the remarkable therapeutic effects of tamoxifen on SLE of (NZBxNZW)F1 female mice and suggest that these beneficial effects are related to the specific reduction of IgG3 autoantibodies.

Reflections on the management of reproductive failure in the antiphospholipid syndrome--the clinician's perspective

It is well known that women with systemic lupus erythematosus (SLE) who have antiphospholipid antibodies (aPL) are at increased risk for pregnancy loss. Additionally, other reproductive processes, such as unexplained infertility and implantation failure after in vitro fertilization and embryo transfer may be affected by aPL. Thus, clinical manifestations of the so-called 'gynaeco-obstetrical antiphospholipid syndrome' have been expanded into the concept of the 'reproductive autoimmune failure syndrome'. However, this is still a matter of debate with no general agreement with respect to both pathophysiological significance of the presence of aPL and patient management. This article analyses a number of controversies in the management of reproductive failure potentially associated with aPL in order to help clinicians dealing with such condition in daily clinical practice.