Regulatory effect of antiphospholipid antibodies on signal transduction: A possible model for autoantibody-induced reproductive failure

Anticardiolipin and/or anti-β2-glycoprotein-I antibodies are associated with adverse IVF outcomes

OBJECTIVE

The purpose of the study is to evaluate the effects of anticardiolipin (aCL) and/or anti-β2-glycoprotein-I (aβ2GPI) antibodies, namely antiphospholipid antibodies (aPL), on in vitro fertilization (IVF) outcomes.

MATERIALS AND METHODS

The study group comprised infertile women with aPL undergoing IVF-ET cycles. Controls were infertile women with tubal etiology without aPL. The impact of aPL on reproductive outcomes, such as oocyte quality, embryo quality, and implantation capacity, was compared between the study group and controls. Additionally, peripheral blood T cell subsets, such as T helper (Th)1, Th2, Th17, and T regulatory (Treg) cells and cytokines, were analyzed by the flow cytometry. Differences between the study group and controls were analyzed.

RESULTS

A total of 132 infertile women, including 44 women with aPL, and 88 controls were sequentially recruited for this study. Women with aPL had lower numbers of total and perfect/available embryos and lower rates of MII oocytes, blastocyst formation, perfect and available embryos, implantation, clinical pregnancy, and take-home baby. Additionally, imbalanced Th1/Th2 and Th17/Treg ratios, significantly higher levels of serum IL-2, TNF-α, IFN-γ, and IL-17A, and a significantly lower serum IL-4 were noticed in women with aPL compared to controls.

CONCLUSION

Women with aPL such as aCL and/or aβ2GPI antibodies were associated with adverse IVF outcomes. Early screening for aPL and appropriate consultation for couples undergoing IVF should be considered. In addition, underlying immunopathology and inflammatory immune mechanisms associated with aPL should be further explored.

Impact of presence of antiphospholipid antibodies on in vitro fertilization outcome

Objective

To investigate prevalence of antiphospholipid antibody (APA) in Korean infertile women undergoing the first in vitro fertilization (IVF) treatment and to evaluate the influence of APA on the subsequent IVF outcomes.

Method

Two hundred nineteen infertile women who destined the first IVF were prospectively enrolled in 2 infertility centers. Male factor or uterine factor infertility and women with past or current endocrine or immunologic disorders were completely excluded. Plasma concentration of lupus anticoagulant was measured by clot-based method, and anticardiolipin antibody (IgG/IgM), and anti-β2-glycoprotein 1 antibody (IgG/IgM) was measured by enzyme-linked immunosorbent assay method before starting ovarian stimulation for IVF.

Results

APA was positive in 13 women (5.9%). Lupus anticoagulant was positive in 2 women (0.9%), anticardiolipin antibody was positive in 7 women (3.2%), and anti-β2-glycoprotein 1 antibody was positive in 4 women (1.8%). In 193 women entering embryo transfer, clinical characteristics and stimulation outcomes were comparable between APA-positive (n=12) and APA-negative group (n=181). The clinical pregnancy rate (66.7% vs. 45.9%), ongoing pregnancy rate (58.3% vs. 37.0%), and miscarriage rate (12.5% vs. 19.3%) were all similar between APA-positive and APA-negative group.

Conclusion

The prevalence of APA is low in Korean infertile women undergoing the first IVF cycle, and the presence of APA appears to neither decrease their first IVF success nor increase abortion rate.

Functional autoantibodies targeting G protein-coupled receptors in rheumatic diseases

G protein-coupled receptors (GPCRs) comprise the largest and most diverse family of integral membrane proteins that participate in different physiological processes such as the regulation of the nervous and immune systems. Besides the endogenous ligands of GPCRs, functional autoantibodies are also able to bind GPCRs to trigger or block intracellular signalling pathways, resulting in agonistic or antagonistic effects, respectively. In this Review, the effects of functional GPCR-targeting autoantibodies on the pathogenesis of autoimmune diseases, including rheumatic diseases, are discussed. Autoantibodies targeting β1 and β2 adrenergic receptors, which are expressed by cardiac and airway smooth muscle cells, respectively, have an important role in the development of asthma and cardiovascular diseases. In addition, high levels of autoantibodies against the muscarinic acetylcholine receptor M3 as well as those targeting endothelin receptor type A and type 1 angiotensin II receptor have several implications in the pathogenesis of rheumatic diseases such as Sjögren syndrome and systemic sclerosis. Expanding the knowledge of the pathophysiological roles of autoantibodies against GPCRs will shed light on the biology of these receptors and open avenues for new therapeutic approaches.

Effects of anti-β2-GPI antibodies on cytokine production in normal first-trimester trophoblast cells

AIM

The anti-β2-GPI antibody (aβ2-GPIAb) has been detected in recurrent fetal loss with strong pathogenic activity. The effects of aβ2-GPIAb on cytokine production and aβ2-GPIAb binding sites in first-trimester trophoblast cells were evaluated.

METHODS

First-trimester trophoblast cells were cultured in 24-well tissue culture plates with immunoglobulin G (IgG) obtained from aβ2-GPIAb-positive and aβ2-GPIAb-negative serum. Cytokines in the cultured supernatant were measured using the suspension array system and enzyme-linked immunosorbent assays. To identify potential binding sites for aβ2-GPIAb, such as toll-like receptors (TLR) 2 or TLR4, we used mouse monoclonal anti-TLR2 and/or anti-TLR4 antibodies to inhibit TLR and then measured cytokine production.

RESULTS

The production of cytokines, such as interleukin-6 and interleukin-8, increased more in response to aβ2-GPIAb-positive IgG than to aβ2-GPIAb-negative IgG in trophoblast cells. The secretion of cytokines from trophoblast cells decreased when the TLR were blocked with mouse monoclonal anti-TLR2 and anti-TLR4 antibodies.

CONCLUSION

We suspect that aβ2-GPIAb might increase cytokine production by binding to TLR2 or TLR4. The increased cytokine production in response to aβ2-GPIAb might play a role in the increased inflammatory response in the placenta.

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.

Autoantibodies and coagulation in reproductive medicine

Management of recurrent pregnancy loss (RPL) is considered to be difficult, in part because of cunfusion between autoantibodies and coagulation disorders. Autoantibodies and coagulation are related; two groups of multicenter studies concerning autoantibodies and coagulation reported that factor XII deficiency, hypofibrinolysis, anti-phosphatidylethanolamine (aPE), anti-beta2-glycoprotein I, anti-annexin A5, and lupus anticoagulant (LA) were found to be frequent risk factors in RPL women. Therefore, discrimination of autoantibodies and coagulation is important in understanding RPL well. We propose three types of pathways regarding reproduction, which are different and independent: (1) Negatively charged-phospholipid related antibodies (anti-phosphatidylserine; aPS, anti-cardiolipin; aCL, lupus anticoagulant; LA, anti-annexin A5; aANX), (2) factor XII-aPE-fibrinolysis: suppression of fibrinolysis, (3) protein C-protein S-factor V: loss of inactivation against activated factor V. Women with RPL and infertility showed similar findings in terms of the above clinical tests. Available data, however, is not enough to conclude whether these are pathogenic to infertile women.

The detection of anti-β2-glycoprotein I antibodies is associated with increased risk of pregnancy loss in women with threatened abortion in the first trimester

OBJECTIVE

This study was designed to evaluate whether the detection of serum antiphospholipid autoantibodies may be useful in predicting pregnancy outcome in women with threatened abortion in the first trimester.

STUDY DESIGN

A group of 77 pregnant women of between 8 and 12 weeks' gestation with vaginal bleeding was tested for serum antiphospholipid, lupus anticoagulants, anticardiolipin, antinuclear antibodies, and anti-beta2-glycoprotein I antibodies, and was followed up until the spontaneous end of pregnancy. A control group composed of 15 healthy women with uncomplicated gestation was tested contemporarily for the same antibody panel.

RESULTS

Of the 77 patients with threatened abortion, 32 (41.5%) progressed to deliver at term and 45 (58.5%) experienced early pregnancy loss. Among the antibodies evaluated, only anti-beta2-glycoprotein I was significantly more frequent in those women whose pregnancy resulted in spontaneous abortion (22/45, 49%) than in those who progressed to term (6/32, 19%) or in the control group (2/15, 13%; p=0.004). This difference was specific to the IgM isotype (p=0.001). After adjustment by multivariate analysis, the odds ratio for pregnancy loss associated with a positive beta2-glycoprotein I antibody test was 5.18 (p=0.001).

CONCLUSION

The detection of anti-beta2-glycoprotein I antibodies is associated with an increased risk of pregnancy loss in women with threatened abortion in the first trimester.

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.

Prophylactic Therapy for Patients with Reproductive Failure Who were Positive for Anti-Phospholipid Antibodies

PROBLEM

To elucidate the efficacy of the treatment using a Japanese-modified Chinese herbal medicine, Sairei-to, and low-dose aspirin with or without a corticosteroid hormone for the patients with adverse pregnancy histories positive for anti-phospholipid antibodies.

METHOD OF STUDY

Fifteen cases positive for anti-phospholipid antibodies, who had experienced preterm delivery in which an extremely low birthweight infant (<1000 g) was born as a result of intrauterine growth restriction with or without severe preeclampsia, were treated with the medication according to the current protocol. Four cases with the same condition, who were treated with only low-dose aspirin, or without medication, were chosen as a control population. The pregnancy outcome was compared between the two groups.

RESULTS

The rate of patients in whom the next pregnancy continued until the 36th week of gestation or later was significantly higher in treated patients (80.0%) compared with the control population (0%).

CONCLUSIONS

In this series, we obtained case report data that Sairei-to may provide some benefit for patients with reproductive disorders positive for anti-phospholipid antibodies; however, randomized controlled trial evidence is needed before current treatment can be recommended.

Prostaglandins and reproduction in female farm animals

Prostaglandins impact on ovarian, uterine, placental, and pituitary function to regulate reproduction in female livestock. They play important roles in ovulation, luteal function, maternal recognition of pregnancy, implantation, maintenance of gestation, microbial-induced abortion, parturition, postpartum uterine and ovarian infections, and resumption of postpartum ovarian cyclicity. Prostaglandins have both positive and negative effects on reproduction; they are used to synchronize oestrus, terminate pseudopregnancy in mares, induce parturition, and treat retained placenta, luteinized cysts, pyometra, and chronic endometritis. Improved therapeutic uses for prostaglandins will be developed when we understand better their involvement in implantation, maintenance of luteal function, and establishment and maintenance of pregnancy.

Anti-Phospholipid Antibodies against Phosphatidylinositol, and Phosphatidylserine are More Significant in Reproductive Failure than Antibodies against Cardiolipin only

PROBLEM

The humoral immune response to phospholipids was investigated in women with reproductive failure [1073 women after one in vitro fertilization (IVF), 853 women after two and more IVF, 627 women after three and more repeated spontaneous miscarriages or missed abortions, 412 women after diagnostic laparoscopy] and compared with that of 391 healthy fertile women.

METHOD OF STUDY

Sera from all women in the study were tested by enzyme-linked immunosorbent assay (ELISA) for the detection of IgG, IgA, and IgM isotypes of antibodies against seven phospholipids (aPLs), i.e. cardiolipin, L-phosphatidylserine, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, phosphatidylacid as well as against beta2-glycoprotein I.

RESULTS

Patients after two and more IVF (48 and 50%, respectively), patients with three and more repeated spontaneous miscarriages (50 and 46.5%, respectively) are associated with significantly higher serum levels of aPLs against inositol, and L-serine (P < 0.01). A quarter of them were positive for three and more aPLs.

CONCLUSION

It seems that determination of aPLs only against cardiolipin in reproductive failure is not sufficient for obstetric-gynecology diagnosis as the primary anti-phospholipid syndrome. Our long-ranging study (from 1998 to 2003) shows the necessity to test for a complete aPLs profile. Sera from patients after two and more IVF procedures, and sera from women after three and more repeated abortions are immunologically more active than sera from women after one unsuccessful IVF and sera from women after diagnostic laparoscopy. This important result is very significant for future treatment.

Endometriosis in reproductive immunology

PROBLEM

Endometriosis is suggested to represent an autoimmune disorder, but what is the prevalence of autoantibodies to antigens relevant to reproduction?

METHOD OF STUDY

The humoral immune response to the women with endometriosis (stage I-II: 261 women; stage III-IV: 62 women) in serum and in peritoneal fluid was investigated compared with 101 healthy women. Enzyme-linked immunosorbent assay (ELISA) was used in all the women for the detection of seven antiphospholipid antibodies [antiphospholipid antibodies (aPLs) against cardiolipin, L-phosphatidyl (ph)-serine, ph-glycerol, ph-inositol, ph-ethanolamine, phosphatidic (ph)-acid and against beta2-glycoprotein I] of class IgG, IgA, and IgM. A passive haemmagglutination method and ELISA (BioGen) was used for assessment of antizona pellucida antibodies (aZP), tray agglutination test (TAT) and indirect mixed anti-imunoglobulin reaction test (MAR-test) for the determination of sperm antibody levels.

RESULTS

Endometriosis I-II were associated with higher serum and peritoneal fluid levels of aPLs against inositol, cardiolipin, ethanolamine, and beta2-glycoprotein I. Forty percent of patients were positive for aZPA.

CONCLUSIONS

Patients with lesions of endometriosis stage I-II had more autoantibodies than those with stage III-IV, and may be immunologically more active. This result may be significant for future treatments such as in vitro fertilization and embryo transfer.

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.

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.

Suppressive effect of anticardiolipin antibody on the proliferation of human umbilical vein endothelial cells

OBJECTIVE

To determine whether sera that show a positive anticardiolipin test result have a suppressive effect on the proliferation of endothelial cells collected from human umbilical veins.

DESIGN

Retrospective in vitro study.

SETTING

University hospital outpatient clinic for the treatment of infertility.

PATIENT(S)

Thirteen patients with recurrent fetal miscarriages who were positive for anticardiolipin antibody and 14 patients with recurrent miscarriages who were negative for anticardiolipin antibody.

INTERVENTION(S)

Serum was obtained from each patient.

MAIN OUTCOME MEASURE(S)

Suppressive effect of the sera on the culture of human umbilical vein endothelial cells.

RESULT(S)

The proliferation of human umbilical vein endothelial cells decreased significantly in cultures that contained sera showing positive anticardiolipin antibody activity that had been collected from patients with recurrent fetal miscarriages.

CONCLUSION(S)

The results strongly suggest that anticardiolipin antibody has a suppressive effect on the proliferation of human umbilical vein endothelial cells.

Effect of anticardiolipin antibodies on prolactin and insulin-like growth factor binding protein-1 production by human decidual cells

PROBLEM

The effect of anticardiolipin antibodies (ACAs) on basal- and growth factor-stimulated prolactin and insulin-like growth factor (IGF) binding protein (BP)-1 production by cultured human decidual cells was investigated.

METHOD OF THE STUDY

Decidual cells were cultured for 24, 48, or 96 hr in medium supplemented with 5% ACA-containing or 5% control serum and increasing concentrations of insulin (1-10 micrograms/mL) or IGF-1 (10-100 ng/mL).

RESULTS

No significant increase in prolactin production was observed after addition of increasing doses of insulin and IGF-I in the presence of ACA-containing serum, while a dose-dependent stimulation was seen with control serum. Time-dependent prolactin accumulation was also reduced when cells were cultured in the former conditions. IGF BP-1 release was not affected by insulin and IGF-I in the presence of both sera. However, lower IGF BP-1 levels and a less pronounced time-dependent accumulation were observed in the presence of ACA-positive serum.

CONCLUSIONS

Our data suggest that ACAs affect cellular transduction mechanisms regulating critical events, such as decidual cell differentiation. These cellular dysfunctions might be relevant in the induction of some obstetric disorders typical of this syndrome.

Antiphospholipid antibodies inhibit prostaglandin release by decidual cells of early pregnancy: possible involvement of extracellular secretory phospholipase A2

OBJECTIVE

To investigate the effect of antiphospholipid antibodies on eicosanoid production by human decidual cells and the in vitro interaction between antiphospholipid antibodies and secretory phospholipase A2.

DESIGN

Cultures of human decidual cells from early pregnancy.

SETTING

All decidual specimens were obtained from the Obstetrics and Gynecology Department of the Catholic University, Rome, Italy.

PATIENT(S)

Patients were undergoing operative laparoscopy for extrauterine pregnancy, with a period of amenorrhea ranging from 6 to 9 weeks.

INTERVENTION(S)

Decidual samples were collected at laparoscopy by routine uterine curettage.

MAIN OUTCOME MEASURE(S)

Decidual cells were incubated with antiphospholipid antibodies, and eicosanoids (prostaglandin [PG] E2, PGF2alpha, and thromboxane B2) were assayed by RIA after 24 hours of culture. In vitro interactions between antiphospholipid antibodies and secretory phospholipase A2 were investigated with use of a modified ELISA for phospholipase A2.

RESULT(S)

Antiphospholipid antibodies reduced eicosanoid release from decidual cells in a dose-dependent fashion. In vitro assays showed that antiphospholipid antibodies bound secretory phospholipase A2 and that a competition occurred between antiphospholipid antibodies and secretory phospholipase A2 for the common substrate cardiolipin.

CONCLUSION(S)

In light of the critical role played by eicosanoids in decidual function, we suggest that an interaction between antiphospholipid antibodies and secretory phospholipase A2 occurring in vivo might impair important cellular communications at the decidual level in the antiphospholipid antibody syndrome.

Antiphospholipid antibodies and reproduction: the antiphospholipid antibody syndrome

In women who have a diagnosis of APS (both clinical and laboratory criteria) the chance for successful pregnancy is reduced. In these cases, treatment appears to be a clear option, particularly in the case of prior thromboembolic events. The current preference of treatment for women with RPL and aPL antibodies is subcutaneous heparin and aspirin. This treatment should begin with a positive pregnancy test and continue postpartum. It is unclear, at this time, what treatment, if any, is required for women who do not meet all the criteria for diagnosis of APS, but who are known to have aPL antibodies. In some cases, these women were tested because of a prior false-positive test for syphilis, with subsequent identification of aPL antibodies. More recently, women undergoing IVF were tested and found to have an increased incidence of aPL antibodies. It was suggested that aPL antibodies are associated with infertility and failure to implant. However, a summary of published reports indicate that positive aPL antibodies in patients undergoing IVF do not influence ongoing pregnancy rates. This subject, however, remains an area of active investigation because aPL antibodies were shown to interact with the syncytiotrophoblast and cytotrophoblast layers and could, theoretically, after implantation.

Human leukocyte antigen class II genotype in patients with recurrent fetal miscarriage who are positive for anticardiolipin antibody

OBJECTIVE

To elucidate the relationship between human leukocyte antigen (HLA) class II genotypes and patients with recurrent fetal miscarriage who are positive for anticardiolipin antibody.

DESIGN

Prospective clinical study.

SETTING

Institutional practice at the outpatient clinic for infertility, Niigata University Medical Hospital.

PATIENT(S)

Patients with recurrent fetal miscarriage who were positive for anticardiolipin antibody and normal fertile women.

INTERVENTION(S)

Genomic DNA was extracted from peripheral mononuclear cells.

MAIN OUTCOME MEASURE(S)

Human leukocyte antigen class II genotype was determined using a polymerase chain reaction restriction fragment length polymorphism method.

RESULT(S)

The frequencies of DRB1*0403 and DRB1*0410 were significantly higher in the patient group than in the control group. The frequency of DRB1*04 also was significantly higher in the patient group. As for HLA-DQ genotype, the frequency of HLA-DQB1*0501 was significantly lower in the patient group.

CONCLUSION

Human leukocyte antigen systems appear to be involved in the genesis of antiphospholipid syndrome.

The role of placental trophoblast in the pathophysiology of the antiphospholipid antibody syndrome

PROBLEM

The antiphospholipid (aPL) antibody syndrome is characterized by severe pregnancy complications, the cause of which remains unknown. We hypothesized that the placental trophoblast is a target for aPLs.

METHOD OF STUDY

The effects of monoclonal aPLs on trophoblast function, including the invasion of JAR into matrigel-coated filters and the effects of annexin V expression on BeWo, were investigated using choriocarcinoma models.

RESULTS

aPLs against phosphatidylserine (PS) significantly (P < 0.001) decreased the migration of JAR across the membrane. In the annexin V studies, undifferentiated BeWo did not express surface annexin V. After differentiation, BeWo expressed surface annexin V, which was removed in the presence of aPLs, resulting in increased binding of prothrombin.

CONCLUSIONS

PS is expressed on the trophoblast surface during differentiation and invasion of extracellular matrix. Our data suggest that aPLs against PS can directly affect trophoblast function by limiting the depth of decidual invasion and by concurrently creating a procoagulant surface on trophoblast exposed to the maternal circulation.

Autoantibody screening for infertility: explaining the unexplained?

Several laboratories currently offer panels of serum autoantibody assays to screen women with unexplained infertility and those undergoing in vitro fertilization (IVF). Offering these tests implies that they have predictive value for the outcome of proposed infertility treatments such that the results of the testing would alter clinical management. Because screening for antiphospholipid antibodies adds expense to already costly procedures, it is an appropriate time to review the justification for the use of these panels.

Chromosome analysis of aborted conceptuses of recurrent aborters positive for anticardiolipin antibody

OBJECTIVE

To elucidate the relationship between anticardiolipin antibody and recurrent abortion.

DESIGN

Prospective clinical study.

SETTING

Institutional practice in which patients with recurrent abortion were registered at the outpatient clinic for infertility of Niigata University Hospital.

PATIENT(S)

Five hundred sixty-one patients with recurrent abortions and 148 patients who were not recurrent aborters and who had experienced sporadic abortion.

INTERVENTION(S)

Aborted conceptuses for chromosome analyses were collected from the patients.

MAIN OUTCOME MEASURE(S)

The positive rate of anticardiolipin antibody was assessed in patients with recurrent abortion. Chromosome analyses of aborted conceptuses were performed in 10 patients with positive anticardiolipin antibody who had experienced another pregnancy that resulted in repeated abortion. Similar analyses of aborted conceptuses from 148 sporadic early abortions (controls) were performed.

RESULT(S)

The incidence of chromosome abnormalities in anticardiolipin antibody-positive recurrent aborters was 20.0% (2 of 10 cases), which was significantly lower than that of patients with sporadic abortion (60.1%, 89 of 148 cases).

CONCLUSION(S)

The low incidence of chromosome abnormalities in aborted conceptuses of patients with positive anticardiolipin antibody suggests that this antibody is strongly implicated in the genesis of recurrent abortions.

Anti-phospholipid antibodies in preeclampsia and their binding ability for placental villous lipid fractions

OBJECTIVE

In order to investigate the significance of the anti-phospholipid antibodies (APAs) in preeclampsia, 3 kinds of APAs-namely, the anti-cardiolipin antibody (ACA), the anti-phosphatidylserine antibody (APSA), and the anti-phosphatidylcholine antibody (APCA)-were measured, and the APA-binding ability for placental villi using villous lipid fractions was studied.

METHODS

Serum samples were taken from 70 cases of preeclampsia, including 42 cases of the severe type, and from 45 normal pregnant women. The APAs were measured by an enzyme linked immunoabsorbent assay (ELISA). Placental villous membranes (PVMs) from normal placenta were purified and the lipid fractions were extracted from PVMs. The antibody-binding ability for PVM lipid fractions was evaluated by the ELISA method.

RESULTS

In IgG-antibody measurements, the rate of ACA-positive, APSA-positive and APCA-positive cases were 10.0%, 18.1%, and 7.1%, respectively. The presence of APAs was revealed in preeclampsia. Using thin-layer chromatography, negatively charged phospholipids were found in the lipid fractions obtained from PVMs. Antibody binding for the lipid fractions of PVMs was detected in 9 of 12 APA-positive cases in preeclampsia.

CONCLUSION

The results suggest that one cause of preeclampsia is the production of antiphospholipid antibodies that bind to placental villous membrane antigens.

Antiphospholipid antibodies and pregnancy disorders in women with insulin dependent diabetes

Insulin dependent diabetes (IDD) is considered to be an immune endocrinopathy as in such patients a disorder of the immune system is involved; however, up to now no data are available on the occurrence of antiphospholipid antibodies (aPL) in IDD pregnant women and on possible correlation between the presence of aPL and the high fetomaternal morbidity reported in these patients. The presence of lupus anticoagulant (LA) and of anticardiolipin antibodies (ACA) was monthly evaluated. In 35 IDD pregnant women referring within the 7 degrees week of pregnancy to the High Risk Pregnancy Medical Unit. Levels of D-dimer, fibrin degradation product, were also assayed. Twelve IDD pregnant women resulted to be aPL positive with a markedly high prevalence of positivity (34%). aPL positive did not significantly differ from aPL negative women in age, duration and severity of diabetes and in metabolic control throughout pregnancy. Pregnancy induced hypertension (PIH) and intrauterin growth retard (IUGR) were observed in 6/12 aPL positive and in only 2/23 aPL negative patients (p < 0.02). A pathological increase in D-dimer levels occurred in 6/12 aPL positive patients and in none aPL negative (p < 0.03). The high frequency of aPL positivity and its strict relation to pregnancy complications strongly support a major role for an autoimmune pathogenetic mechanism in the occurrence of feto-maternal morbidity in IDD pregnant women. The identification of this subgroup at risk for complications may be clinically relevant.

Laboratory evaluation of women experiencing reproductive failure

Reproductive life table analysis indicates that the majority of reproductive failures result from post fertilization failures, whether before or after implantation. It is important to have a set of tests to clarify the diagnosis of the reproductive failure so that appropriate therapy can be instituted. To determine the frequency of abnormal immunologic tests among women experiencing reproductive failure, 108 patients were evaluated for the presence of antiphospholipid antibodies (APA); lupus anticoagulant (LA); thyroid-thyroglobulin and microsomal antibodies (TGT); embryotoxic factor (ETA); and systemic CD56+/CD16- cells. The frequency of abnormal results obtained from testing for APA, LA, TGT, ETA, and CD56+/CD16- cells among 108 patients with diagnoses of recurrent pregnancy loss (RPL)(n = 45), unexplained infertility (n = 45) including IVF failure (n = 10), endometriosis (n = 10), premature ovarian failure (n = 5), and polycystic ovaries (n = 3) were compared with 15 normal controls. Seventy of one hundred eight (65%) women experiencing reproductive failure had at least one positive test, compared to 1 of 15 (7%) controls (P = 0.0001). Presence of phospholipid antibodies was the most frequently abnormal result followed by elevated CD56+/CD 16 cells. The prevalence of a particular abnormal test varied among the diagnoses. The most frequent abnormal test among women with RPL was an increased percentage of CD56+/CD16- cells (40%), followed by APAs (29%), TGT (9%), and ETA (7%). The most frequent abnormal result among women with unexplained infertility was the presence of APAs (42%), followed by CD56+/CD16- cells (16%), ETA (16%), and TGT (9%). APA, CD56+/CD16- cells, ETA, and TGT are useful tools to assist in the diagnosis of reproductive failure.

The antiphospholipid-protein syndrome

The pathogenesis of the antiphospholipid syndrome remains uncertain. Antibodies that react with phospholipids may not be directly responsible for cellular injury, but may be part of the immune network through which autoantibodies with pathogenic potential are generated. The latter may recognize proteins such as beta 2-glycoprotein I that form complexes with phospholipids, proteins whose functions depend upon interaction with phospholipids such as protein C and its cofactors, altered lipoproteins such as oxidized low-density lipoproteins, or other molecules that share only antigenic similarity. Thus, a spectrum of autoantibodies that recognize different lipid-protein complexes may develop in these patients and contribute to the observed clinical heterogeneity of the syndrome. Current techniques do not permit identification of the subset of patients with antiphospholipid antibodies at risk for thrombosis or abortion and there are no prospective, controlled trials addressing the prophylaxis or treatment of affected individuals. Identification of the cellular targets of antibodies to lipid-protein moieties is needed to identify patients at risk for these complications and as a means to monitor therapy.

Pre-eclampsia: physiology and immunological aspects

Pre-eclampsia is a frequent, unpredictable syndrome which is dangerous for both mother and foetus. The concept of placental ischemia has gained wide acceptance among the numerous theories put forward to explain the illness. The setting up of preeclampsia seems to be scheduled in two steps: (1) an absolute or relative placental ischemia due to vascular diseases or hypertrophic placenta, or most often secondary to implantation defect, particularly anomaly with the invasive trophoblast; (2) a diffuse endothelial disease. The connection between these two steps is incompletely disclosed. The authors demonstrate that the maternal immune system which is strongly stressed during all the stages of normal gestation is implicated in pre-eclampsia. Its role is probably not univocal. Foeto-trophoblastic antigens could be poorly recognised. This defect of recognition could lead to the abnormalities of trophoblastic invasion observed in pre-eclampsia. Pre-eclampsia does not seem to be accompanied by an immunological rejection of the foetus. Some genetically predisposed patients do not have a sufficiently competent immune system to neutralise one or more of the toxic products released by the ischemic placenta. Certain types of pre-eclampsia could be auto-immune, with the auto-antibodies directed against certain types of phospholipids or trophoblastic constituents. A disequilibrium between oxidation and anti-oxidation mechanisms involving neutrophils could lead to aggression of the endothelium which is observed in pre-eclampsia. Pre-eclampsia could represent a form of immuno-dystrophy, with the excessive production of adverse cytokines locally, directed against the trophoblast. Without directly implicating the immune system as the trigger of pre-eclampsia, it seems that its role is unclear. In some cases it develops protective mechanisms which, when overwhelmed or inadequate, allows pre-eclampsia to occur. In other cases it can form part of the cascade of aggressions leading to the abnormalities encountered. The integration of these abnormalities in the pathophysiological models, could help improve the classification of pre-eclampsia. This attempt will lead to a more adapted preventive and therapeutic management of pre-eclampsia.

Specific antiphospholipid antibodies (aPL) eluted from placentae of pregnant women with aPL-positive sera

The mechanism by which antiphospholipid antibodies (aPL) cause recurrent pregnancy loss remains unclear. It has however been reported that aPL may affect cytotrophoblasts in vitro and thus direct placental damage might occur. Therefore, we investigated whether aPL are bound directly to placental tissues in patients with immunoglobulin G (IgG)-aPL positive sera. The material investigated comprised the placentae of six patients with a history of recurrent pregnancy loss and subclinical autoimmune disorder and one with systemic lupus erythematosus, who were treated with a combination of prednisolone and aspirin. Normal controls consisted of placentae derived from six women, negative for serum aPL, with no medical or obstetrical complication during their pregnancy. Five kinds of IgG- and IgM-antiphospholipid (anti-PS, PI, PA, PG and CL) antibodies were eluted from the placentae of both patients and controls, which were measured by enzyme-linked immunosorbent assay. IgG-aPL were detected in the placental eluates of four of seven (57%) patients, whereas IgM-aPL were not found in any. With respect to the pregnancy outcome of the four patients with IgG-aPL-positive placental eluates, one experienced intrauterine fetal death (IUFD) at 23 weeks of gestation and three demonstrated intrauterine growth retardation (IUGR). In contrast, the remaining three patients, evaluated negative for IgG-aPL in placental eluates, gave birth to one baby with IUGR and two appropriate-for-date babies. The placentae of the four mothers with IgG-aPL-positive placental eluates pathologically showed severe thrombotic findings. These results suggest that IgG-aPL can directly bind to placental tissue and might cause pathologic damage resulting in IUFD or IUGR.

Down-regulation of maternal antiphospholipid antibodies during early pregnancy and pregnancy outcome

OBJECTIVE

We investigated the hypothesis that maternal autoimmune responses to phospholipid antigens measured before and during pregnancy are not related to successful pregnancy outcome.

STUDY DESIGN

One hundred twenty-three women with recurrent spontaneous abortions were serially tested for antiphospholipid antibodies during their pregnancies.

RESULTS

In 72 women with recurrent spontaneous abortions and without antiphospholipid antibodies before the pregnancy, the incidence of antiphospholipid antibody production at the time of pregnancy termination was significantly higher in those who miscarried the index pregnancy than those who were delivered of a live-born infant. In 51 antiphospholipid antibody-positive women with recurrent spontaneous abortions there were dramatic increases in titers of anticardiolipin antibody and antiphosphatidylserine antibody in those who miscarried the index pregnancy (p < 0.005). In women who were delivered of a live-born infant, the titers remained stable or decreased during pregnancy.

CONCLUSIONS

Down-regulation of antiphospholipid antibody production during early pregnancy is associated with favorable pregnancy outcome.

Effect of prostaglandin F2 alpha on uterine or ovarian secretion of prostaglandins E and F2 alpha in vivo in 90-100 day hysterectomized, intact or ovariectomized pregnant ewes

Vehicle or 8 or 16 mg of PGF2 alpha per 58 kg body weight was given intramuscularly to intact, hysterectomized or ovariectomized 90-100 day pregnant ewes in three separate experiments. Both doses of PGF2 alpha increased PGF2 alpha in ovarian venous plasma compared with controls at 72 hr post treatment in intact (P < or = 0.05) but did not in hysterectomized (P > or = 0.05) 90-100 day pregnant ewes. Concentrations of PGE in ovarian venous blood of intact ewes did not differ (P > or = 0.05) between treatment groups and were equivalent to concentrations of PGE determined in uterine venous plasma. PGE was decreased in ovarian venous plasma by PGF2 alpha in hysterectomized ewes (P < or = 0.07). PGE in uterine venous plasma averaged 6 ng/ml over the 72-hr treatment period in intact and ovariectomized 90-100 day pregnant ewes and was 12 fold greater (P < or = 0.05) than PGF2 alpha which averaged 500 pg/ml in uterine venous plasma. Both PGF2 alpha and PGE increased (P < or = 0.05) by 64 hr in uterine venous plasma of the 8 mg PGF2 alpha-treated intact pregnant ewes. A significant quadratic increase (P < or = 0.05) was observed for PGF2 alpha and PGE in the vehicle and both PGF2 alpha treatment groups of intact ewes at the end of the 72-hr sampling period. It is concluded that the uterus and ovaries secrete significant quantities of PGF but little PGF2 alpha during midgestation. In addition, PGF2 alpha increased uterine secretion of PGE in vivo. PGE may be a placental stimulator of ovine placental secretion of progesterone or PGE may protect placental steroidogenesis from actions of PGF2 alpha.

What do we really know about autoantibody abnormalities and reproductive failure: a critical review

CONDENSATION

The diagnosis and treatment of autoantibody-associated forms of reproductive failure is critically reviewed.

OBJECTIVE

To critically evaluate the published literature in reference to autoantibody-associated forms of reproductive failure.

LOCATION

Medical School-affiliated private Infertility Center.

MATERIALS

A review of over 200 published papers reflecting on the topic.

RESULTS

Autoantibody associated reproductive failure, characterized by a decrease in fecundity and an increase in the risk of pregnancy loss, appears established. Autoantibody abnormalities, as routinely detected by standard laboratory assays, are, however, neither immunologically nor biologically specific since cross reactivities between autoantibodies are frequent and a specific autoantibody may cause a biological effect in one but not in another affected individual.

CONCLUSIONS

The evaluation of autoantibody abnormalities in all cases of suspected autoimmune-associated reproductive failure is valuable and will improve clinical care of affected patients. Clinicians need, however, to recognize the limitations of autoantibody testing and have to adjust their clinical management to the degree and quality of autoantibody evaluation available to them in their community.

Autoantibodies in normal and abnormal pregnancy

Abnormal autoimmune function has been associated with reproductive failure for decades. In fact, all medical conditions historically associated with pregnancy loss (and on occasion infertility) are now recognized to have an autoimmune etiology. It is therefore quite surprising that only less than a decade ago a correlation between the presence of abnormal autoantibodies and pregnancy loss was reported for the first time. Since reproductive failure, similar to other abnormal autoimmune states, is not a monoclonal event, we have established that affected patients demonstrate polyclonal autoantibody abnormalities including a variety of nonorganospecific as well as organspecific autoantibody groupings. For example, patients with repeated pregnancy loss will exhibit abnormal levels of anti-phospholipid antibodies (PA). In normal pregnancy natural autoantibodies do not follow the standard immunoglobulin (Ig) pattern, characterized by a decrease in levels despite a probably mild increase in production, which is excessively compensated by the vasodilatation of pregnancy. PA, especially, demonstrate a mild increase during pregnancy, though levels only in the peripartal period may reach abnormally high titers (in comparison to nonpregnant controls). This dichotomy between total Ig and natural autoantibodies is interesting since it suggests that autoantibodies may be under distinct control. In fact, we have suggested that this observed elevation of autoantibodies may be the result of an antigenic stimulus by self-like antigen, represented by the maternal growth of the parasitic fetus. In abnormal pregnancies, especially those associated with maternal hypertension and fetal growth retardation (IUGR), autoantibody levels do reach highly abnormal levels.(ABSTRACT TRUNCATED AT 250 WORDS)