Antiphospholipid antibodies in pregnancy

Antiphospholipid antibodies and extracellular vesicles in pregnancy

Antiphospholipid antibodies (aPL) are autoantibodies that target phospholipid-binding proteins, such as β2 glycoprotein I (β2GPI), and can induce thrombosis systemically, as well as increase the risk of obstetric complications such as recurrent miscarriage and preeclampsia. Due to the expression of β2GPI by placental trophoblasts, aPL readily target the maternal-fetal interface during pregnancy and many studies have investigated the deleterious effects of aPL on placental trophoblast function. This review will focus on studies that have examined the effects of aPL on the production and modification of extracellular vesicles (EVs) from trophoblasts, as EVs are a key mode of feto-maternal communication in both normal and pathological pregnancy. A more comprehensive understanding of the effects of aPL on the quantity and cargo of EVs extruded by the human placenta may contribute to our current knowledge of how aPL induce both systemic and obstetric disease.

Antiphospholipid antibodies increase the levels of mitochondrial DNA in placental extracellular vesicles: Alarmin-g for preeclampsia

The pathogenesis of preeclampsia remains unclear but placental factors are known to play a crucial role causing maternal endothelial cell dysfunction. One potential factor is placental micro- and nano- vesicles. Antiphospholipid antibodies (aPL) increase the risk of preeclampsia ten-fold, in part by damaging the mitochondria in the syncytiotrophoblast. Since mitochondrial DNA (mtDNA) is a danger- associated molecular pattern (DAMP/alarmin) that may activate endothelial cells, the aims of the current study were to investigate whether aPL affect the number of placental vesicles extruded, their mtDNA content and their ability to activate endothelial cells. Exposure of first trimester human placental explants to aPL affected neither the number nor size of extruded micro- and nano- vesicles (n = 5), however their levels of mtDNA were increased (n = 6). These vesicles significantly activated endothelial cells (n = 5), which was prevented by blocking toll-like receptor 9 (TLR-9), a receptor for extracellular DNA. Thus, aPL may increase the risk of preeclampsia in part by increasing the amount of mtDNA associated with placental vesicles. That mitochondrial DNA is recognised as a DAMP by TLR-9 to cause endothelial cell activation, raises the possibility that placental vesicles or TLR-9 might be a target for pharmaceutical intervention to reduce the consequences of aPL in pregnancy.

Pregnancy outcomes of antiphospholipid syndrome: In a low resource South Asian setting

PROBLEM

Antiphospholipid syndrome is associated with recurrent pregnancy loss, and specific treatment improves pregnancy outcome. Laboratory diagnosis is limited in South Asia. We assessed management outcomes of definite/probable antiphospholipid syndrome treated at a tertiary centre in Sri Lanka.

METHOD

Descriptive cross-sectional study of pregnancy outcomes with heparin and aspirin therapy.

OUTCOME MEASURES

miscarriage, intrauterine death and live birth when compared to previous untreated pregnancies.

RESULTS

Of 646 gestations in 145 women, 146 (22.6%) received specific treatment. In the preceding pregnancies without specific treatment, the rates of miscarriage, late fetal loss, stillbirth and live birth were 60%, 26%, 8% and 7%, respectively. Following specific treatment with low-dose aspirin ± low-molecular weight heparin in 146 pregnancies (145 women), the rates of miscarriage, late fetal loss, stillbirth and live birth were 14%, 10%, 3% and 74%, respectively. Mean birth weight was 2.54 ± 0.62 kg, preterm births complicated 32 (29.6%) with a mean gestational age at delivery 33.7 ± 2.6 weeks, with three neonatal deaths. Maternal complications were: pre-eclampsia 16 (10.9%), gestational diabetes 28 (19.2%), antepartum haemorrhage in 1 patient. Only 73/145 (50.3%) women had laboratory confirmation of antiphospholipid syndrome, while others were treated empirically. Live births in diagnosed vs. empiric treatment - 80.8% vs. 67.1%.

CONCLUSION

Pregnant women with clinical antiphospholipid syndrome when treated with low-dose aspirin and heparin, the live birth rate of 7% in the previous pregnancy resulted in live births of 74% in a resource limited South Asian setting.

The Antiphospholipid Thrombosis Syndromes: A Common Multidisciplinary Medical Problem

Antiphospholipid antibodies are increasingly being identified as a cause of arterial and venous thrombosis as well as fetal wastage syndrome via placental vascular thrombosis. The antiphospholipid thrombosis syndromes should be considered and searched for when suggestive clinical findings are present or when unexplained arterial or venous thrombosis occurs. Noting the presence and type of antiphospholipid antibody thrombosis syndrome assumes major importance with respect to not only making an accurate diagnosis of cause of thrombosis but also in selecting effective antithrombotic therapy. The antiphospholipid thrombosis syndromes and the thrombotic and other clinical manifestations span almost all medical specialities and should be construed as a truly multidisciptinary medical problem. Key Words: Thrombosis-Anticardiolipin antibody—Lupus anticoagulant.

Human extravillous trophoblasts bind but do not internalize antiphospholipid antibodies

INTRODUCTION

Obstetric morbidity in women with antiphospholipid antibodies (aPLs) may reflect the adverse effects of aPLs on placental cells such as extravillous trophoblasts and the syncytiotrophoblast. Antiphospholipid antibodies may affect the syncytiotrophoblast after being internalised by members of the Low-density lipoprotein receptor (LDLR) family and the antigen of aPLs, β2 glycoprotein I.

AIM

This study aimed to determine whether aPL internalization was a mechanism by which aPLs adversely affect extravillous trophoblasts.

METHOD

of

STUDY

Fluorescently-labelled monoclonal aPLs IIC5 or ID2 were incubated with first trimester extravillous trophoblast outgrowths and visualized by microscopy. The subcellular expression of β2 glycoprotein I and LDLR family members was investigated by live/permeabilised immunocytochemistry.

RESULTS

Unlike the syncytiotrophoblast of anchoring villi, monoclonal aPLs were not internalised by extravillous trophoblasts, which expressed LDLR family members intracellularly. The aPL IIC5 bound to the surface of extravillous trophoblasts in a pattern similar to the extracellular expression of β2 glycoprotein I.

CONCLUSIONS

The mechanisms of action of aPLs are different in extravillous trophoblasts and the syncytiotrophoblast. The interaction of aPLs with the extravillous trophoblast surface, which may involve β2 glycoprotein I, is consistent with reports that aPLs trigger intracellular signaling cascades through cell-surface receptors.

Histopathology in the placentae of women with antiphospholipid antibodies: A systematic review of the literature

BACKGROUND

Antiphospholipid antibodies (aPLs) are a heterogenous group of autoantibodies associated with recurrent miscarriage, stillbirth, foetal growth restriction and premature birth. The cause of obstetric morbidity in women with aPLs is not completely understood. Workers have attempted to understand the role of aPLs in obstetric morbidity by investigating the histopathology of placentae from aPL-positive women. However, it is unclear from these diverse, and at times contradictory reports what histopathological lesions are common in the placentae of women with aPLs. This systematic review was undertaken to generate a complete picture of the placental features associated with aPLs in an attempt to understand the pathological processes that occur in pregnancies affected by aPLs.

METHODS

Pubmed, Scopus, Web of Science and Embase were searched on the 27th November 2014 using the keywords "placenta" OR "trophoblast" AND "antiphospholipid antibody" OR "antiphospholipid antibody syndrome". Records that were relevant and eligible were qualitatively assessed and given a score out of 24.

RESULTS

Of the 1112 records that were retrieved from the systematic search, 34 records were eligible for review, and were qualitatively scored. Of the 44 histopathological features that were reported in 580 placentae from aPL-positive women, six features appeared to be more common in the placentae of aPL-positive women compared to control women, including: placental infarction, impaired spiral artery remodelling, decidual inflammation, increased syncytial knots, decreased vasculosyncytial membranes and the deposition of complement split product C4d.

CONCLUSION

Based on the evidence in this systematic review, a human placental aPL fingerprint has been proposed. The diversity of the human placental aPL fingerprint suggests that multiple pathological processes may occur in pregnancies affected by aPL.

Association of anticardiolipin antibodies with preeclampsia: a systematic review and meta-analysis

OBJECTIVE

To systematically review the evidence of the association of anticardiolipin antibodies with preeclampsia.

DATA SOURCES

PubMed and LILACS were perused up to June 2009, citations were searched using the ISI Web of Knowledge database, textbooks and reference lists were reviewed, and experts were contacted. Search terms included "antiphospholipid syndrome," "Hughes' syndrome," "anticardiolipin antibodies," "antiphospholipid antibodies," "anti-cardiolipin," "preeclampsia," and "pre-eclampsia."

METHODS OF STUDY SELECTION

Inclusion criteria were: cohorts, case-control, or controlled cross-sectional studies; healthy pregnancy as controls; no autoimmune diseases; immunoglobulin (Ig)G, IgM anticardiolipin antibody of at least 20 units by enzyme-linked immunosorbent assay, or both; and end-point preeclampsia.

TABULATION, INTEGRATION, AND RESULTS

Our search generated 68,528 entries and 64 full-text articles were reviewed. Twelve studies were included in the meta-analysis. Pooled odds ratio (OR) for association of anticardiolipin antibodies with preeclampsia was 2.86 (95% confidence interval [CI], 1.37-5.98). Pooled OR for anticardiolipin antibodies and severe preeclampsia was 11.15 (95% CI 2.66-46.75). Funnel plot showed minor asymmetry, and the Egger test was not significant (P=.359). Meta-regression identified study design and size as related to heterogeneity.

CONCLUSION

Moderate-to-high levels of anticardiolipin antibodies are associated with preeclampsia, but there is insufficient evidence to use anticardiolipin antibodies as predictors of preeclampsia in clinical practice.

Prevalence and significance of antiphospholipid antibodies in selected at-risk obstetrics cases: a comparative prospective study

In a prospective comparative study we screened 112 women with a past history either of pre-eclampsia, eclampsia, recurrent abortion, IUGR, IUFD or abruptio placentae, with no apparent aetiology and a demographically matched cohort of 106 women having a past history of uncomplicated pregnancy outcome for the presence of antiphospholipid antibodies (aPL) and their significance. In the former group, the prevalence of aPL ranged from 10-46.87% compared with 8.49% in the later group. In women with the presence of aPL, the incidence of pre-eclampsia, early onset pre-eclampsia and abruptio placentae were 25%, 14.58% and 18.75%, respectively. In the same group, the abortion rate was 25% and live-birth rate was 64.58% with IUFD rate of 10.42%. Fetal morbidity rates were also higher in the mothers with aPL positivity, the incidence of IUGR was 27.08% and oligohydramnios was 33.33% in them. All these complications were statistically significant when compared with those of aPL negative mothers.

Pregnancy outcome in different clinical phenotypes of antiphospholipid syndrome

Women with antiphospholipid syndrome (APS) may have diverse pregnancy outcomes. The objective of this study was to evaluate pregnancy outcome in women with APS according to their clinical phenotype, i.e. thrombotic and obstetric APS. Eighty-three pregnancies in 67 women with APS were included in the study, including 21 with recurrent miscarriage (Group 1), 21 with late fetal loss or early delivery due to placental dysfunction (Group 2) and 41 with thrombotic APS (Group 3). Group 3 had higher rates of preterm delivery (26.8% versus 4.7%, p = 0.05) than Group 1 and more small for gestational age (SGA) babies than Group 2 (39.5% versus 4.8%, p = 0.003). Group 2 had significantly longer gestations compared with their pretreatment pregnancies (38.4 [28.4—41.4] versus 24.0 [18—35] weeks, p < 0.0001) and 100% live birth rate after treatment with aspirin and low-molecular-weight heparin (LMWH). In conclusion, women with thrombotic APS (Group 3) have higher rates of pregnancy complications than those with obstetric APS (Groups 1 and 2). Treatment with aspirin and LMWH is associated with improved outcomes for women with previous late fetal loss or early delivery due to placental dysfunction (Group 2). Lupus (2010) 19, 58—64.

The epidemiology of recurrent miscarriage: A descriptive study of 1214 prepregnant women with recurrent miscarriage

AIMS

To describe the characteristics of the prepregnant population attending the Recurrent Miscarriage Clinic (RMC) at the National Women's Hospital (NWH), Auckland, between 1986 and 2003, and to compare them with the overall obstetric booking population of the hospital.

METHODS

The identifying details of 1214 prepregnant women attending the RMC were obtained. Both hospital and RMC records, which were kept separately, were retrospectively reviewed for demographic information and results of diagnostic investigations. Data from Auckland residents who attended the clinic were compared with data from all Auckland women booking or delivering at NWH.

RESULTS

RMC attendees were older than the general NWH population, but had similar parity. Clinic attendees had a higher incidence of personal and family history of antepartum haemorrhage, fetal abnormalities, stillbirths and neonatal deaths than reported rates for the general population. Chromosomal anomalies were detected in 86 women, reproductive tract anomalies were found in 142 women, and polycystic ovarian syndrome was detected in 49 women. The majority (52.7%) of women had no identifiable cause for recurrent miscarriage detected.

CONCLUSIONS

These data support the concept of women with recurrent miscarriage being at high risk for adverse obstetric outcomes including fetal abnormalities, stillbirths and neonatal deaths, even when the pregnancies are ongoing. We conclude that recurrent miscarriage is different from subfertility, and provide information of use in planning care for such women.

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.

Obstetric complications due to autoantibodies

Autoimmune diseases are most common and most active in young women; it is therefore not uncommon for obstetricians and physicians to encounter pregnant women with these conditions, and knowledge of the potential maternal, foetal and neonatal complications is essential for good clinical management. The most common maternal autoimmune endocrine conditions in pregnancy are insulin-dependent diabetes mellitus and thyroid disease. Other relatively common non-endocrine autoimmune conditions include systemic lupus erythematosus and anti-phospholipid syndrome. Much rarer autoimmune conditions include autoimmune thrombocytopenia, rheumatoid arthritis, myasthenia gravis and Addison's disease. In this chapter, we discuss autoimmune endocrine conditions and briefly mention some non-endocrine conditions of particular importance.

The immunological profile of infertile women after repeated IVF failure (preliminary study)

OBJECTIVE

The aim of this preliminary study was to estimate the immunological profile of patients after repeated IVF failures.

MATERIALS AND METHODS

Seventeen women after repeated IVF failure and 10 non-pregnant women with a history of successful IVF pregnancies were included in the study. We estimated the presence of the auto-antibodies, such as: antinuclear antibodies (ANA), antithyroid antibodies (ATA), antiphospolipid antibodies (APA), antismooth muscle antibodies (ASMA), and antisperm antibodies (ASA). Furthermore, we estimated the percentage of B-1 CD 19+5+ lymphocytes and NK cells using flow cytometry.

RESULTS

In the group of patients after IVF failure the percentage of B-1 CD 19+5+ lymphocytes was higher than 1.5% and significantly higher when compared to controls. Three patients after IVF failure had elevated percentages of peripheral blood NK cells. Fourteen infertile patients after IVF failure (82.3%) had at least one abnormal result on autoimmune testing. One patient from the study group had no positive results of immunological tests.

CONCLUSION

Our results suggest that immunological alterations may be involved in the etiopathogenesis of unexplained infertility. Furthermore, the results suggest that there is a need for immunological diagnostics in the group of patients with unexplained infertility A greater number of patients is needed for further investigations.

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.

Antiphospholipid thrombosis syndromes

Antiphospholipid antibodies are associated strongly with thrombosis and are the most common of the acquired blood protein defects causing thrombosis. Although the precise mechanisms whereby antiphospholipid antibodies alter hemostasis to induce a hypercoagulable state remain unclear, numerous theories, as previously discussed, have been advanced. The most common thrombotic events associated with ACLAs are deep vein thrombosis and pulmonary embolus (type I syndrome), coronary or peripheral artery thrombosis (type II syndrome), or cerebrovascular/retinal vessel thrombosis (type III syndrome), and occasionally patients present with mixtures (type IV syndrome). Patients with type V disease are those with antiphospholipid antibodies and RMS. It is as yet unclear how many seemingly normal individuals who may never develop manifestations of antiphospholipid syndrome (type VI) harbor asymptomatic antiphospholipid antibodies. The relative frequency of ACLAs in association with arterial and venous thrombosis strongly suggests that they should be looked for in any individual with unexplained thrombosis; all three idiotypes (IgG, IgA, and IgM) should be assessed. Also, the type of syndrome (I-VI) should be defined, if possible, because this identification may dictate both the type and the duration of immediate and long-term anticoagulant therapy. Unlike those patients with ACLAs, patients with primary LA-thrombosis syndrome usually have venous thrombosis. Because the aPTT is unreliable in patients with LA (prolonged in only approximately 40%-50% of patients) and usually is not prolonged in patients with ACLAs, definitive tests, including ELISA for ACLA, the dilute Russell's viper venom time for LA, hexagonal phospholipid-neutralization procedure, and B-2-GP-I (IgG, IgA, and IgM) should be ordered immediately when suspecting antiphospholipid syndrome or in individuals with otherwise unexplained thrombotic or thromboembolic events. If these test results are negative, subgroups also should be assessedin the appropriate clinical setting. Most patients with antiphospholipid thrombosis syndrome will fail to respond to warfarin therapy, and except for retinal vascular thrombosis, may fail some types of antiplatelet therapy, so it is of major importance to make this diagnosis so patients can be treated with the most effective therapy for secondary prevention-LMWH or unfractionated heparin in most instances and clopidogrel in some instances.

The effects of IgG purified from women with SLE and associated pregnancy loss on rat embryos in culture

PROBLEM

Recurrent fetal loss occurs in approximately 1% of women. Autoimmune causes have been suggested as a factor in some of these cases. High rates of intrauterine fetal growth retardation and increased incidence of prematurity is associated with systemic lupus erythematosus (SLE) and the anti-phospholipid syndrome (APS). Autoantibodies from sera of SLE/APS patients affect reproductive outcome in pregnant mice, as was studied in vivo, where injection of immunoglobulin (Ig)G purified from patients with APS to mice caused fetal resorptions and growth retardation.

METHODS

In order to investigate the direct effect of IgG purified from women with SLE or APS on the growth and viability of embryos, we cultured 11.5-day old-rat embryos in their yolk sacs in the presence of IgG purified from SLE and APS patients.

RESULTS

IgG purified from SLE and recurrent pregnancy loss (RPL) patients affected directly the embryo and yolk sac reducing their growth. The purified IgG positive for anti-cardiolipin/anti-DNA antibodies reduced yolk sac and embryonic growth more than sera negative for these antibodies.

CONCLUSION

Various antiphospholipid antibodies affect differently the growth and development of the embryo and the placenta.

Hemostatic problems before, during and after delivery

Normal pregnancy and childbirth are known to be associated with marked changes in the coagulation and fibrinolytic systems. Generally, enhancement of clotting activity persists to prevent the risk of major hemorrhage. Hemostatic problems, either associated with a specific complication of pregnancy and labor or due to a hereditary or acquired bleeding diathesis or thrombophilias, present a significant cause of maternal and neonatal morbidity and mortality. This article reviews hemostatic disorders in pregnancy and the peripartal period from the standpoint of the obstetrician.

Antiphospholipid thrombosis syndromes

Antiphospholipid antibodies are strongly associated with thrombosis and are the most common of the acquired blood protein defects causing thrombosis. Although the precise mechanism(s) whereby antiphospholipid antibodies alter hemostasis to induce a hypercoagutable state remain unclear, numerous theories, as previously discussed, have been advanced. The most common thrombotic events associated with anticardiolipin antibodies are deep vein thrombosis and pulmonary embolus (type I syndrome), coronary or peripheral artery thrombosis (type II syndrome), or cerebrovascular/retinal vessel thrombosis (type II syndrome); occasionally, patients present with mixtures of these types (type IV syndrome). Type V patients are those with antiphospholipid antibodies and RMS. It is as yet unclear how many seemingly normal individuals who may never develop manifestations of antiphospholipid syndrome (type VI) harbor asymptomatic antiphospholipid antibodies. The relative frequency of anticardiolipin antibodies in association with arterial and venous thrombosis strongly suggests that these should be looked for in any individual with unexplained thrombosis; all three idiotypes (IgG, IgA, and IgM) should be assessed. Also, the type of syndrome (I through VI) should be defined if possible, as this may dictate both type and duration of both immediate and long-term anticoagulant therapy. Unlike those with anticardiolipin antibodies, patients with primary lupus anticoagulant thrombosis syndrome usually experience venous thrombosis. Because the aPTT is unreliable inpatients with lupus anticoagulant (prolonged in only about 40 to 50% of patients) and is not usually prolonged in patients with anticardiolipin antibodies, definitive tests, including ELISA for anticardiolipin antibodies, the dRVVT for lupus anticoagulant, hexagonal phospholipid neutralization procedure, and beta-2-GP-I (IgG, IgA, and IgM) should be immediately ordered when suspecting antiphospholipid syndrome or in individuals with otherwise unexplained thrombotic or thromboembolic events. If results of these tests are negative, in the appropriate clinical setting, subgroups should also be assessed. Finally, most patients with antiphospholipid thrombosis syndrome will fail warfarin therapy and, except for retinal vascular thrombosis, may fail some types of antiplatelet therapy; thus it is of major importance to make this diagnosis so that patients can be treated with the most effective therapy for secondary prevention--LMWH or UH in most instances, and clopidogrel in some instances.

Management of pregnancy in antiphospholipid syndrome

Pregnant women with APS are at high risk of maternal and fetal pregnancy complications. Multidisciplinary teams expert in this condition should coordinate management. Even with current management strategies, the risk of maternal thrombosis, fetal loss, or other adverse obstetric outcomes remains. Close monitoring of the various aspects of this condition may reduce maternal morbidity and improve fetal outcome. The pathogenesis of the adverse pregnancy outcome in APS has not yet been fully elucidated, although active research in this field continues. Until this is ascertained, we must accept that many aspects of management are purely empiric, and it is our duty to counsel patients thoroughly so that they understand the risks and benefits of the treatment options they are offered.

Antithrombotic therapy in high-risk pregnancy

Venous thromboembolism remains a major cause of morbidity and mortality associated with pregnancy and puerperium. Specific risk factors for this disorder can be identified before or during pregnancy and delivery. The heritable defects believed to be associated with venous thrombosis are factor V Leiden mutation; elevated antiphospholipid antibodies; and deficiencies of antithrombin, protein C, and protein S. Women with a history of thromboembolism and thrombophilia should receive antenatal and postpartum thrombosis prophylaxis.

Conformationally altered beta 2-glycoprotein I is the antigen for anti-cardiolipin autoantibodies

Anti-cardiolipin autoantibodies (aCL) induce thrombosis and recurrent fetal death. These antibodies require a 'cofactor', identified as beta 2-glycoprotein I (beta 2-GPI), to bind phospholipids. We show here that aCL can bind beta 2-GPI in the absence of phospholipid. Binding of aCL to beta 2-GPI is dependent upon the beta 2-GPI being immobilized on an appropriate surface including cardiolipin, irradiated polystyrene and nitrocellulose membrane. This effect cannot be explained by increased antigen density of beta 2-GPI immobilized on these surfaces. Rather, conformational changes that occur following the interaction of beta 2-GPI with phospholipid render this protein antigenic to aCL. Liquid-phase beta 2-GPI was not antigenic for aCL. Thus, aCL cannot bind circulating beta 2-GPI. These findings may explain why patients with aCL can remain healthy for many years but then undergo episodes of thrombosis or fetal loss without changes in their circulating aCL profile, as the triggering event for these pathologies can be predicted to be one that renders beta 2-GPI antigenic for aCL.

Pregnancy complications in women with recurrent miscarriage associated with antiphospholipid antibodies treated with low dose aspirin and heparin

OBJECTIVE

To study the obstetric course of women with a history of recurrent miscarriage associated with antiphospholipid antibodies, lupus anticoagulant and anticardiolipin antibodies, treated with low dose aspirin and low dose heparin.

DESIGN

Prospective observational study.

SETTING

University based tertiary referral clinic.

POPULATION

One hundred and fifty pregnant women with a history of recurrent miscarriage associated with persistently positive tests for antiphospholipid antibodies.

METHODS

Lupus anticoagulant was detected using the dilute Russell's viper venom time together with a platelet neutralisation procedure. IgG and IgM anticardiolipin antibodies were detected using a standardised enzyme linked immunosorbent assay. An IgG anticardiolipin level > or = 5 per litre units and an IgM anticardiolipin level > or = 3 per litre units was considered positive. Aspirin (75 mg daily) was commenced at the time of a positive pregnancy test and heparin (5000 units subcutaneously 12 hourly, or enoxaparin 20 mg daily) was started when fetal heart activity was demonstrated on ultrasound. Treatment was stopped at the time of miscarriage or at 34 weeks of gestation.

RESULTS

One hundred and seven pregnancies (71%) resulted in a live birth. Forty-one pregnancies (27%) miscarried, the majority in the first trimester. One woman had a stillbirth, and one a premature baby who died in the neonatal period. One pregnancy was terminated for a fetal anomaly. Gestational hypertension complicated 17% (18/108) of ongoing pregnancies and antepartum haemorrhage 7% (8/108). Twenty-six babies (24%) were delivered before 37 weeks of gestation. Fifty women (46%) were delivered by caesarean section. The median birthweight of all live born infants was 3069 g (range 531-4300); however 15% (16/108) of the infants were small for gestational age.

CONCLUSION

Combination treatment with aspirin and heparin leads to a high live birth rate among women with recurrent miscarriage and antiphospholipid antibodies. However, successful pregnancies are prone to a high risk of complications during all trimesters. Close antenatal surveillance and planned delivery of these pregnancies in a unit with specialist obstetric and neonatal intensive care facilities are indicated.

Adverse pregnancy outcome in the antiphospholipid syndrome: focus for future research

Pregnant patients with antiphospholipid syndrome (APS) may suffer from recurrent pregnancy loss, pre-eclampsia, intrauterine growth restriction and placental abruption. These conditions inevitably result in a high incidence of premature delivery with all the neonatal complications that follow. The mechanism underlying these adverse pregnancy outcomes has not yet been established. This may be primarily a maternal disease process with secondary placental maldevelopment and/or malfunction. Alternatively, there may be primary placental damage mediated directly or indirectly by antiphospholipid antibodies. The safe and successful treatment of pregnant women with APS lies in the understanding of the aetiology of this condition and the mechanism by which complications in pregnancy may arise. In this article we highlight areas in which research may be targeted such that our understanding of the pathogenesis of adverse pregnancy outcome may be enhanced.

Antiphospholipid antibodies or not? The role of beta 2 glycoprotein 1 in autoantibody-mediated pregnancy loss

Antiphospholipid antibodies are a family of autoantibodies including lupus anticoagulant and anticardiolipin antibodies that appear to react with negatively charged phospholipids. These antibodies induce thrombosis and pregnancy complications including recurrent stillbirth, recurrent miscarriage, pre-eclampsia and intra-uterine growth retardation. Recent evidence indicates that antiphospholipid antibodies do not bind directly to phospholipid but rather to phospholipid-binding proteins or to a combination of phospholipid and phospholipid-binding proteins. This opens the possibility that antiphospholipid antibodies may be pathogenic by disrupting the function of phospholipid-binding proteins rather than membrane phospholipid. The antigenic role of one phospholipid-binding protein, beta 2 glycoprotein, has been studied in the greatest detail and is reviewed. Despite being highly conserved and expressed at high levels, the physiological function of beta 2 glycoprotein 1 remains unknown. However, a number of putative roles have been proposed which allow speculation as to the mechanism by which antiphospholipid antibodies may disrupt haemostasis and pregnancy.

Acquired thrombophilia

The antiphospholipid syndrome is the most common cause of acquired thrombophilia. For obstetricians, it is important because of its association with recurrent miscarriage as well as either venous or arterial thrombosis. The evidence linking anticardiolipin antibodies and the lupus anticoagulants with thrombosis will be examined, as will the diagnostic dilemmas which arise. Thromboprophylaxis, both during pregnancy and lifelong, as well as for gynaecological surgery, will be discussed, as will management options for women suffering from recurrent miscarriage.

Midfollicular anticardiolipin and antiphosphatidylserine antibody titers do not correlate with in vitro fertilization outcome

OBJECTIVE

To determine the prevalence of anticardiolipin and antiphophatidylserine antibodies in an IVF population and to correlate their presence and specific isotype with IVF cycle outcome.

DESIGN

Retrospective clinical study using stored midfollicular sera for determination of antibody status.

SETTING

University hospital infertility clinic.

PATIENT(S)

Women who underwent IVF treatment in 1991.

INTERVENTION(S)

Midfollicular sera were used to assess antibody status during the time of stimulation for IVF.

MAIN OUTCOME MEASURE(S)

Anticardiolipin and antiphosphatidylserine antibody titers and biochemical or sonographic documentation of IVF cycle outcome.

RESULT(S)

The overall prevalence of anticardiolipin and antiphosphatidylserine antibodies in IVF patients was 7.0% and 11.2%, respectively. There was no statistically significant difference in the prevalence of these antibodies in the groups of patients with a biochemical pregnancy (0 for anticardiolipin and 2.8% for antiphosphatidylserine), spontaneous miscarriage (11.4% for anticardiolipin and 20% for antiphosphatidylserine), ongoing pregnancy (7.3% for anticardiolipin and 11.6% for antiphosphatidylserine), and patients who failed to conceive (7.2% for anticardiolipin and 10.8% for antiphosphatidylserine). There was no correlation between outcome and the antibody isotype expressed.

CONCLUSION(S)

Anticardiolipin and antiphosphatidylserine antibodies are poorly predictive of the IVF cycle outcome. Routine testing of IVF patients for the presence of these antibodies is of limited clinical utility.

Thyroid antibodies and their relation to antithrombin antibodies, anticardiolipin antibodies and lupus anticoagulant in women with recurrent spontaneous abortions (antithyroid, anticardiolipin and antithrombin autoantibodies and lupus anticoagulant in habitual aborters)

OBJECTIVE

This study was undertaken to evaluate the incidence of thyroid autoantibodies in women with a history of recurrent spontaneous abortions (RSA) and to investigate their relationship to non-organ specific autoantibodies.

STUDY DESIGN

28 euthyroid non-pregnant habitual aborters were analysed for thyreoglobulin (TG), thyroid peroxidase antibodies (TPO), and autoantibodies to thromboplastin, cardiolipin and lupus anticoagulant. 28 multigravidae without previous abortions or endocrine dysfunctions served as controls.

RESULTS

11 of 28 women with recurrent spontaneous miscarriage (39%), but only 2 of 28 controls (7%) (Chi square test: p < 0.01) demonstrated positive titres of TG, TPO, or both antibodies, 12 patients were positive for antithrombin antibodies and 3 for anticardiolipin. Only one women was lupus anticoagulant positive. No significant correlation between thyroid antibody positivity and positivity for antiphospholipids (Fisher's exact test: p = 0.441), anticardiolipin (p = 0.664) or lupus coagulant (p = 0.607) was found.

CONCLUSIONS

The incidence of thyroid antibodies in euthyroid women with recurrent pregnancy loss appears to be significantly increased compared with controls of reproductive age without previous abortions. No correlation between the presence of thyroid autoantibodies and non-organ specific autoantibodies could be established.

Anticardiolipin antibodies in pregnancy induced hypertension

It was suggested that anticardiolipin antibodies (ACA) were found positive in some obstetrical problems such as recurrent foetal losses, intrauterine growth retardation, etc. The aim of this study was to determine ACA levels in pregnancy induced hypertension (PIH) cases. ACA IgG and IgM levels were measured by the ELISA method in 65 PIH cases and 23 control pregnancies. We could not find any difference between the PIH and the control groups. There was not any statistically significant difference between the subtypes of PIH. According to these results, we say that ACA IgG and IgM levels have no diagnostic and prognostic value in PIH.

Antiphospholipid antibodies in patients with preeclampsia

PROBLEM

To determine the incidence of anticardiolipin and antiphosphatidylserine antibodies in women with preeclampsia.

METHODS

Sera from 100 women with preeclampsia and 100 normotensive pregnant women in the third trimester were assayed for anticardiolipin and antiphosphatidylserine antibodies.

RESULTS

Antiphosphatidylserine antibodies were positive for IgM in 1 patient (1%) and for IgG in 4 patients (4%). IgM antibodies to cardiolipin were positive in two patients (2%) while IgG antibodies to cardiolipin were positive in nine patients (9%). Only 3% of the control women were positive for antiphospholipid antibodies. None of the patients or controls had positive levels of IgA anticardiolipin or antiphosphatidylserine antibodies.

CONCLUSIONS

Elevated levels of IgG or IgM antibodies to cardiolipin and phosphatidylserine were detected in 11/100 (11%) of women diagnosed with preeclampsia in the third trimester compared to only 3/100 (3%) positive in controls (P < or = 0.05). These findings suggest that antiphospholipid antibodies may play a pathogenic role in some women with preeclampsia.

The effect of human anticardiolipin antibodies on murine pregnancy

Anticardiolipin antibodies (aCL) were affinity purified or isolated in the IgG fraction of serum from 6 patients with antiphospholipid antibody syndrome. Anticardiolipin antibodies from one patient consistently compromised murine pregnancy. However in 92% (45 of 49) of cases injection of human anticardiolipin antibodies had no adverse effect on murine pregnancy, regardless of whether affinity purified aCL or IgG fractions were used. It is concluded that in most cases human anticardiolipin antibodies alone do not induce murine fetal loss.

Pregnancy complicated by the antiphospholipid syndrome

A patient with previously undiagnosed antiphospholipid syndrome (APS) developed atypical severe preeclampsia at 31 weeks' gestation. Other complications of pregnancy included intrauterine growth retardation, thrombocytopenia and fetal distress necessitating urgent delivery of a live infant. There was a prior history of unexplained jugular venous thrombosis. Prophylaxis against thrombosis was commenced immediately postoperatively and no postpartum complications occurred. Recent evidence supports the use of antepartum prophylaxis with low dose heparin in patients with APS. The role of low dose aspirin, either alone or in combination with heparin, is yet to be determined. Human immunoglobulin may be useful in selected cases. Early diagnosis is a key factor in their management.