Antiphospholipid antibodies and recurrent pregnancy loss: correlation between the activated partial thromboplastin time and antibodies against phosphatidylserine and cardiolipin

Acquisition of anti-phosphatidylserine IgM and IgG antibodies by infants and their mothers over time in Uganda

Background

Production of anti-phosphatidylserine (anti-PS) antibodies has been associated with malaria and can aggravate pathology. How these autoantibodies develop during early childhood in a malaria context is not known. We examined levels of anti-PS IgG and IgM antibodies in a longitudinal cohort of mother-baby pairs during birth, in the infants at 2.5, 6 months, and in mothers and their babies at 9 months postpartum.

Results

There was no difference between levels of anti-PS IgG in cord blood and the mothers' peripheral blood at birth. However, anti-PS IgM levels were significantly higher in the mothers compared to the infants' cord blood, and IgM levels were steadily increasing during the first 9 months of the infants' life. In infants that had the highest anti-PS IgM levels at birth, there was a decline until 6 months with a rise at 9 months. Infants that possessed high anti-PS IgG at birth also exhibited a progressive decline in levels. When anti-PS were correlated to different fractions of B-cells, there were several correlations with P. falciparum specific atypical B cells both at birth and at 2.5 months for the infants, especially for anti-PS IgM. Anti-PS also correlated strongly to C1q-fixing antibodies at birth.

Conclusion

These results show that anti-PS IgG acquired by mothers could be transferred transplacentally and that IgM antibodies targeting PS are acquired during the first year of life. These results have increased the knowledge about autoimmune responses associated with infections in early life and is critical for a comprehensive understanding of malaria vaccine functionality in endemic areas.

Profiling of non-criteria antiphospholipid antibodies in patients with SLE: differentiation of thrombotic SLE patients and risk of recurrence of thrombosis

To reveal the clinical significance of criteria and non-criteria antiphospholipid antibodies detected by line immunoassay in comparison with ELISA, systemic lupus erythematosus patients with and without thrombotic events were investigated. Thus, 107 systemic lupus erythematosus patients (48% with deep vein thrombosis or/and arterial thrombosis) and 120 healthy donors were enrolled. Serum antiphospholipid antibodies were detected by ELISA (Orgentec Diagnostika, Germany) and line immunoassay (GA Generic Assays, Germany). Lupus anticoagulant and IgG to cardiolipin and β2GPI but not IgM as well as triple positivity by ELISA and line immunoassay were linked with thrombosis in systemic lupus erythematosus. IgG to phosphatidylinositol and phosphatidylserine by line immunoassay showed significantly higher levels in systemic lupus erythematosus with deep vein thrombosis/arterial thrombosis than without and were independent risk factors for deep vein thrombosis (odds ratio 3.9, 95% confidence interval 1.1, 13.2) and arterial thrombosis (odds ratio 5.1, 95% confidence interval 1.3, 19.8) as well as thrombosis (odds ratio 3.6, 95% confidence interval 1.1, 11.3) and recurrence thereof (odds ratio 6.9, 95% confidence interval 2.1, 22.6), respectively. The occurrence of >4 IgG antiphospholipid antibodies by line immunoassay was an independent risk factor for thrombosis (odds ratio 10.9, 95% confidence interval 1.2, 101.5), arterial thrombosis (odds ratio 14.6, 95% confidence interval 2.5, 86.3), deep vein thrombosis (odds ratio 5.8, 95% confidence interval 1.0, 32.4) and recurrence of thrombosis (odds ratio 35.9, 95% confidence interval 3.8, 342.8). Line immunoassay is a promising multiplex test for the simultaneous detection of criteria and non-criteria antiphospholipid antibodies. Profiling of antiphospholipid antibodies by line immunoassay can differentiate systemic lupus erythematosus patients with thrombosis from systemic lupus erythematosus patients without and assess the risk for thrombosis and recurrence thereof.

Performance Evaluation and Clinical Associations of Immunoassays That Detect Antibodies to Negatively Charged Phospholipids Other Than Cardiolipin

OBJECTIVES

We evaluate the performance characteristics of antiphosphatidylserine (anti-PS), antiphosphatidylinositol (anti-PI), and antiphospholipid mixture (APhL) enzyme-linked immunosorbent assays (ELISAs) compared with anticardiolipin (aCL) and anti-β2 glycoprotein I (anti-β2GPI) in a large group of patients with antiphospholipid (aPL)-related diseases.

METHODS

Serum samples from 548 patients from the Hopkins and Jamaican systemic lupus erythematosus cohorts, the PROMISSE cohort, and the Antiphospholipid Standardization Laboratory were examined for immunoglobulin G (IgG)/immunoglobulin M (IgM) positivity in aCL, anti-β2GPI, anti-PS, anti-PI, and APhL ELISA assays.

RESULTS

All IgG assays were associated with one or more thrombotic and/or obstetric manifestations, with an increased risk associated with higher antibody titers. Analytical performance was similar among assays, but IgG assays performed better than IgM counterparts.

CONCLUSIONS

Increasing titers of APhL, anti-PS, and anti-PI antibodies could indicate an increased risk of thrombotic and/or obstetric aPL-related manifestations. These assays may be promising biomarkers for particular APS manifestations.

The role of anti-phospholipid antibodies in autoimmune reproductive failure

Anti-phospholipid antibodies (aPL) are autoantibodies that are associated with thrombosis and a range of pregnancy complications including recurrent pregnancy loss and pre-eclampsia. The three clinically relevant, well-characterized aPL are anti-cardiolipin antibodies, lupus anticoagulant and anti-beta-2-glycoprotein I (β2GPI) antibodies. aPL do not bind directly to phospholipids but instead bind to a plasma-binding ‘cofactor’. The most extensively studied cofactor is β2GPI, whose role in pregnancy is not fully elucidated. Although the pathogenicity of aPL in recurrent pregnancy loss is well established in humans and animal models, the association of aPL with infertility does not appear to be causative. aPL may exert their detrimental effects during pregnancy by directly binding trophoblast cells of the placenta, altering trophoblast signalling, proliferation, invasion and secretion of hormones and cytokines, and by increasing apoptosis. Heparin is commonly used to treat pregnant women with aPL; however, as thrombotic events do not occur in the placentae of all women with aPL, it may exert a protective effect by preventing the binding of aPL to β2GPI or by acting through non-thrombotic pathways. The aim of this review is to present evidence summarizing the current understanding of this field.

Antiphospholipid syndrome and the relevance of antibodies to negatively charged phospholipids in diagnostic evaluation

The presence of lupus anticoagulant, moderate-to-high levels of IgG and/or IgM antibodies to beta-2 glycoprotein I or cardiolipin in association with at least one of the two major clinical manifestations (thrombosis and/or pregnancy-related morbidity) are required for a diagnosis of definite antiphospholipid syndrome (APS). The realization that certain negatively charged phospholipid (PL) autoantibodies broadly react with antibodies directed against cardiolipin and may be more reliable and specific markers for APS has led to the search for diagnostic assays with greater predictability for disease evaluation and management. This review focuses on the state-of-the-art analytical and clinical performance of IgG and IgM antibodies directed against negatively charged PLs, specifically phosphatidic acid (aPA), phosphatidylinositol (aPI), and phosphatidylserine (aPS), as well as the APhL assay, which contains a proprietary mixture of phospholipid antigens.

Activated protein C resistance and antiphospholipid antibodies in recurrent fetal loss: experience of a single referral center in northern iraq

The current study was initiated to determine the prevalence of activated protein C (APC) resistance, factor V Leiden and antiphospholipid antibodies (APA) in Iraqi women with recurrent fetal loss (RFL), and evaluate the outcome of intervention in those with such states. For this purpose a total of 103 Iraqi women referred to a major teaching hospital in Northern Iraq with two or more consecutive fetal losses, as well as 100 age matched women with no history of fetal loss and at least one live birth were enrolled. After appropriate clinical evaluation, the enrolled subjects were tested for APA as well as APC resistance. Subjects who were APC resistant were further tested for factor V Leiden mutation using a polymerase chain reaction and reverse hybridization. Patients with documented APA and/or with APC resistance, were put on low dose aspirin with or without low molecular weight heparin during pregnancy, and followed for a minimum of 5 years. The results revealed that among patients' group, APA were detected in 19.4 % compared to 1.0 % of the controls (OR 23.9, p = 0.00005). On the other hand, APC resistance was documented in 9.7 % compared to 1.0 % of the controls (OR 10.6, p = 0.01). Factor V Leiden was detected in 3.9 % of patients and 1 % of the controls (p = 0.38). Among 17 patients with APA available for follow up, there were 24 pregnancies, 18 of which ended with live births (75 %). While among the ten patients who had factor V Leiden or were APC resistant non-carriers, there were 13 pregnancies, 12 ended with live births (92.3 %). In conclusion, this study has demonstrated that among the enrolled Iraqi women, APA and APCR and not factor V Leiden were significantly associated with RFL, and that treatment with aspirin (with or without low molecular weight heparin) had lead to live births in 80.6 % of pregnancies.

Bouquet variety of antiphospholipid antibodies in recurrent pregnancy loss

Seventy-six female patients with two or more recurrent pregnancy losses (RPL) during the 1(st) trimester were studied. Based on the results of the aCL and aB2GPI antibodies testing, patients were divided in two groups: 22 patients with RPL and elevated immunoglobulin (Ig) G/IgM aCL and/or aB2GPI [RPL + antiphospholipid syndrome (APS)] and 54 patients with RPL alone (without high antibodies). Immunoglobulin G aPS and IgG a-AnV in patients with RPL + APS were higher than in controls and IgG aPS were higher in RPL + APS than in RPL alone. Additionally IgG a-AnV and IgM aPE are higher in RPL alone than in controls. In 18/22 (81%) patients with RPL + APS and 29/54 (54%) patients with RPL alone, there were one or more positive antibodies: aPS, aPT, a-AnV or aPE. These results raise a question whether or not these antiphospholipid antibodies should be routinely tested in women with RPL and especially in the context of the so-called "seronegative APS".

The incidence of various antiphospholipid antibodies, measured by commercial-based laboratory, with recurrent spontenous abortion and the impact of their profiles on reproductive outcome with active anticoagulant therapy

Objective. To investigate the incidence of various antiphospholipid antibodies (aPLs), measured by commercial-based laboratory, with recurrent spontaneous abortion (RSA) patients and the impact of the species, isotype, titer, and number of positive aPLs on reproductive outcome in Japanese. Method. In this retrospective cohort study, 263 patients with RSA without possible causes were investigated. Of 131 patients with one or more positive aPL, 82 pregnant women under anticoagulant therapy were evaluated. Results. The incidence of various aPLs was almost consistent with previous report. Overall, successful pregnancy rate with anticoagulant therapy was 91.4% regardless of aPL profiles. There was no significant difference in the pregnancy maintenance rate between IgG and IgM groups or single positive and multiple positive groups, but there was a tendency for the rate with aspirin to be lower than with aspirin plus heparin in IgG group. Conclusion. aPL profile did not affect the pregnancy maintenance rate when anticoagulant therapy was actively introduced, however in IgG group, we recommend combination therapy with aspirin and heparin.

Anti-beta(2)-glycoprotein-I and anti-phosphatidylserine antibodies in women with spontaneous pregnancy loss

OBJECTIVE

To evaluate the role of anti-beta(2)-glycoprotein-I (anti-beta(2)GPI-ab) and anti-phosphatidylserine (aPS-ab) antibodies as a risk factor in both recurrent miscarriage (RM) and unexplained fetal losses (UFL).

DESIGN

Retrospective, cohort study.

SETTING

Vall d'Hebron University Hospital, Barcelona, Spain.

PATIENT(S)

122 pregnant women divided in two groups: study group of 54 women with RM and/or UFL and control group of 68 pregnant without RM history.

INTERVENTION(S)

Analysis of lupus anticoagulant, anticardiolipin antibodies, and anti-beta(2)GP1 and aPS antibodies.

MAIN OUTCOME MEASURE(S)

Comparison of aPL antibody between groups.

RESULT(S)

The prevalence of aPL positive results was 8 out of 54 (14.8%) in the study group and 3 out of 68 (4.41%) in the controls. In the RM subgroup, the prevalence was 3 out of 25 (12%) versus 3 out of 68 (4.4%), and 7 out of 34 (20.6%) versus 3 out of 68 (4.4%) in UFL subgroup. As a whole, the prevalence of anti-beta(2)GP1-ab in the RM/UFL group showed a difference compared with controls but not aPS-ab. In the RM women, anti-beta(2)GP1-ab was positive in 3 out of 25 (12%) versus 1 out of 68 (1.5%) in controls and in 4 out of 34 versus 0 out of 68 cases in women with UFL. In the RM subgroup, aPS-ab was positive in 1 out of 25 (4%) versus 2 out of 68 (2.9%) in control group and in 3 out of 34 versus 2 out of 68 cases in women with UFL.

CONCLUSION(S)

Our results suggest that anti-beta(2)GP1-ab but not aPS-ab is related to RM/UFL and should be considered as a pregnancy-loss risk factor.

A protocol for determination of anticardiolipin antibodies by ELISA

The anticardiolipin (aCL) test has been widely used by physicians since the mid-1980s for diagnosing patients with antiphospholipid syndrome (APS). Establishment of this diagnosis has enabled effective management of patients with recurrent thrombosis or recurrent pregnancy losses. The test was first established in 1983 as a radioimmunoassay and soon thereafter converted into ELISA. There have been numerous efforts to standardize the aCL test, but precise reproducible measurement of aCL levels is difficult and the use of semiquantitative measurements (high, medium and low) is recommended as this is probably sufficient for clinical diagnosis. Using validated ELISAs for measuring aCL Abs offers greater reproducibility, would reduce interlaboratory variations and limit discrepancies in results between different laboratories. This article details a procedure that takes approximately 2 h and summarizes the information available on the aCL ELISA test.

Antiphospholipid antibodies in blood and cerebrospinal fluids of patients with psychosis

Antiphospholipid antibodies (aPL) have been reported in the cerebrospinal fluids (CSF) of neurology patients but no CSF studies with psychiatric patients exist. We tested serum from 100 hospitalized psychotic patients having hallucinations and/or delusions for aPL. Patients with positive serum aPL findings were asked to submit CSF for aPL testing. Five CSF samples had aPL specificities not found in the patient's serum suggesting the possibility of intrathecal synthesis. Specificity and isotype discordance between CSF and blood aPL in these psychiatric patients implicates a central nervous system independent autoimmune process that may have an underlying association with the pathophysiology of their diseases.

Clinical laboratory testing for the antiphospholipid syndrome

The first aCL test was developed in 1983 and subsequently standardized. Although in the last 6 to 7 years, new and more specific tests have become available, the aCL ELISA and the LA tests are still the first choice to be used in diagnosis of APS. While there is now doubt that the anticardiolipin test is useful in the diagnosis of APS, limitations of the assay have caused uncertainty and misinterpretation of the value of the test. Utilization of validated ELISA kits with well-tested calibrators and an "in-house standard" may enable more reproducible measurements. Reporting results semiquantitatively preserves the clinical utilize of the test without the misinterpretation of a quantitative result that may lack precision. The development of newer tests such as the beta2GPI ELISA and the APhL ELISA Kit, utilizing the phospholipid mixture, give promise to a more specific and reliable diagnosis of APS, while retaining good sensitivity. Other tests such as ELISA for prothrombin antibodies and annexin V antibodies are still under development and will require standardization and extensive evaluation. The aCL test should continue to be done and included in the Sapporo criteria. The aCL test is not as specific as the anti-beta2GPI test, but it is very sensitive and together with the LA test should capture the majority of the APS patients. IgA aCL and anti-beta2GPI positivity alone is rare but occasionally found and shown to be associated with major clinical manifestations of APS. Therefore, it is now recommended to include both tests, IgA aCL and IgG, IgM and IgA anti-beta2GPI to confirm diagnosis of APS.

Prognostic impact of anticardiolipin antibodies in women with recurrent miscarriage negative for the lupus anticoagulant

BACKGROUND

Anticardiolipin antibodies (ACA) are found with increased prevalence in women with unexplained recurrent miscarriage (RM) but their impact on future pregnancy outcome in lupus anticoagulant (LAC) negative patients needs better quantification.

METHODS

The impact of a repeatedly positive ACA test on the chance of live birth in the next pregnancy after adjustment for relevant prognostic factors was studied in 147 RM patients who had been included in placebo-controlled trials of immunotherapy. Patients with LAC were excluded and none of the patients received therapy with anticoagulation or prednisone.

RESULTS

60/147 patients (41%) were repeatedly ACA positive according to cut-off values derived from this study. The adjusted odds ratio (OR) for live birth among ACA positive patients was 0.36 (95% CI 0.2-0.7, P = 0.006). Using cut-off values derived from a normal population, the adjusted OR for live birth among ACA positive patients was 0.48 (95% CI 0.2-1.1, P = 0.10). Positivity for IgM ACA was found to be much stronger correlated to pregnancy outcome than IgG ACA.

CONCLUSIONS

In RM women not receiving anticoagulation or prednisone, the presence of ACA in the absence of LAC most likely reduces the chance of live birth by 36-48% compared with the absence of both ACA and LAC. This reduction is inferior to what has been reported from studies where no adjustments for prognostic variables were undertaken and LAC positive patients were included.

Antiphosphatidyl serine antibodies are more common in normotensive women with small for gestational age pregnancies

BACKGROUND

Small for gestational age (SGA) babies are more common in women with antiphospholipid antibodies but data are limited about the prevalence of antiphospholipid antibodies in women who have delivered SGA babies.

AIM

To determine whether elevated levels of anticardiolipin, antiphosphatidyl serine and/or antibeta2 glycoprotein I antibodies are more common in normotensive women who delivered SGA babies compared with women who delivered appropriate for gestational age babies.

METHODS

Case-control study. Cases were normotensive women who delivered an SGA baby (birthweight <10th%) without chromosomal or congenital abnormality. Controls were healthy women who delivered a baby at term with birthweight >10th percentage.

RESULTS

A total of 137 women with SGA pregnancies and 290 controls had antiphospholipid antibodies measured. The prevalence of anticardiolipin and antibeta2 glycoprotein I antibodies did not differ between SGA cases and controls. Antiphosphatidyl serine IgG antibodies were more common in women with SGA pregnancies than controls seven (5%) versus five (1.7%), relative risk (RR) 1.84 (1.12-3.03). There was no difference in the prevalence of 'any antiphospholipid antibodies' between SGA 10 (7.2%) and controls 16 (5.6%). There was a trend to more abnormal umbilical Doppler studies in SGA pregnancies with positive antiphospholipid antibodies three (50%) versus 19 (24%), RR 2.9 (0.62-13).

CONCLUSIONS

Antiphospholipid antibodies were uncommon in this cohort of SGA pregnancies. Further studies are needed in SGA pregnancies with abnormal umbilical Doppler studies to determine if screening for antiphospholipid antibodies is worthwhile in this severe subgroup.

Anticardiolipin antibodies in eclampsia

Twenty patients with eclampsia were studied for the presence of anticardiolipin antibodies by the standard microflocculation test (quantitative) used in the VDRL. Four out of 20 patients (20%) were positive for anticardiolipin antibodies. Anticardiolipin antibodies which are antiphospholipid antibodies by decreasing the prostacyclin production may damage the vascular endothelium and cause thrombosis in the vessels. Hence, the presence of anticardiolipin antibody in eclampsia may have association with antiphospholipid antibody syndrome described by Harris et al. (Lancet ii: 1211, 1983) and its central nervous system sequelae.

Stroke and the antiphospholipid syndrome: consensus meeting Taormina 2002

Ischaemic stroke is the only neurological manifestation accepted as a clinical diagnostic criterion for the antiphospholipid syndrome (APS). This association is reasonably well established in patients first diagnosed with APS but is less clear in randomly selected stroke patients who test positive on one occasion for antiphospholipid antibodies and who have no other evidence of systemic autoimmune disease. We propose a grading system that posits stroke to be definitely, likely or possibly associated with antiphospholipid antibodies (aPL). Further, there are limited prospective data to determine appropriate treatment. There is controversy as to whether the presence of aPL even increases risk of a recurrent stroke or other thromboembolic event, although data point to persistent medium-high titre aCL and/or LA as risk factors for recurrence. In the absence of data to guide clinicians on the best treatment, we cannot make strong recommnendations as to optimal therapy, nor can we propose clear consensus treatment guidelines.

Autoimmune disease as a cause of reproductive failure

High-risk pregnancy is the most common clinical association with antiphospholipid antibodies; the principal manifestations are pregnancy loss and early preeclampsia. Membership in this family of antibodies is continually growing and includes antibodies against a variety of phospholipids, phospholipid-protein complexes, and phospholipid-binding proteins. The current information in the literature is inadequate to clearly implicate a subgroup of antiphospholipid antibodies or a particular pathophysiologic mechanism as being responsible for poor pregnancy outcomes. It is clear, however, that prevalent diagnostic tests for LA and aCL are extremely useful to identify many of these patients, but are inadequate for diagnosis of all patients with autoimmune pregnancy loss or to elucidate the pathophysiology. Many patients who present clinically with autoimmune-like pregnancy complications currently are negative in tests for LA or aCL, but have antibodies against annexin V, phosphatidylserine, or other relevant antigens. The greatest risk for a complicated pregnancy is conveyed by a subgroup of antibodies that affect the normal function of placental trophoblast. As clinical laboratory tests designed to detect more members of the antiphospholipid antibody family become available, understanding of this complicated disease (APS) will increase.

Antiphospholipid antibodies: discovery, definitions, detection and disease

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

Revisiting the anticardiolipin test and its standardization

Although the importance of the anticardiolipin test in diagnosis of antiphospholipid syndrome (APS) is widely accepted, there remains much misunderstanding about the strengths and weaknesses of this assay. Several disorders result in formation of low levels of the antibody, hence the anticardiolipin test is not specific when results are low positive. In general, the higher the anticardiolipin level the greater the likelihood of a diagnosis of APS. Hence there have been numerous efforts to enable reproducible measurement of anticardiolipin levels. Standard calibrators were introduced to construct calibration curves from which levels of unknown samples can be derived. Those standard calibrators were made by mixing varying quantities of high positive with normal sera. More recently, calibrators derived from monoclonal anticardiolipin antibodies have been introduced. There are advantages and disadvantages with both types of calibrators. Determination of a precise and reproducible anticardiolipin level is difficult, whatever the calibrators used, because the assay is dependent on several variable components, any of which may fail on any given day. Utilization of a semi-quantitative measure (low, medium, high) may suffice in most clinical settings and would be less subject to error. Validated ELISA kits may offer greater reproducibility, since there is less variability than bench assays set up in very different laboratories. Whether using a kit or a bench assay, meticulous attention to detail offers the best opportunity for precision and reproducibility.

Phospholipid autoantibodies: time for a new immuno-assay?

Antiphospholipid (aPL) antibodies are a wide and heterogeneous group of closely related immunoglobulins that have specificity for a number of phospholipids (PLs), PL-binding proteins, including beta2 glycoprotein I (beta2GP1), prothrombin, and PL-protein complexes. Antiphospholipid antibodies are currently detected by a standard solid-phase immunoassay such as anticardiolipin (aCL) antibodies. Although the association between aCL antibodies and thrombosis is well recognized, their role in stroke pathogenesis, and the possibility that they are an independent stroke risk factors in the general stroke population, remains to be determined. There are other negatively charged PL, largely represented within the cellular membrane and involved in the coagulation. Different studies have demonstrated a positive correlation among other aPL and stroke.

Mechanisms of syncytial fusion: a review

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

Testing for antiphospholipid antibodies: problems and solutions

The first aCL test was developed in 1983 and subsequently standardized. Although new and more specific tests have become available, the aCL ELISA and the LA tests are still the first choice to be used in diagnosis of APS. Newer tests such as the anti beta 2 GP1 ELISA and the APhL ELISA Kit (Louisville APL Diagnostics) use somewhat different antigens and likely provide a more specific (and possibly more reliable) diagnosis of APS while retaining good-to-excellent sensitivity. Other tests, such as ELISA for prothrombin antibodies and annexin V antibodies, are still undergoing development and will require standardization and extensive evaluation. We thank Dr Isabel Abreu and Dr Mittermeyer B. Santiago for performing some of the studies reported in this review.

Ultrastructural localization of monoclonal antiphospholipid antibody binding to rat brain

Antiphospholipid antibodies (aPL), in the presence or absence of systemic lupus erythematosus, are associated with a number of neurologic complications. However, the role aPL play in pathology is unclear. A thrombotic etiology seems likely for many associated disorders, but not for others. Here we describe aPL-reactive sites in the central nervous system (CNS). Previously, using light microscopy, we showed direct binding of two monoclonal phosphatidylserine-reactive antibodies (aPS) to ependyma and myelin of fixed cat brain. In this study we determined the ultrastructural localization of their binding sites in rat CNS using immunogold electron microscopy techniques. Both monoclonal antibodies reacted strongly with myelin, preferentially with the major dense line formed by the cytoplasmic apposition of the oligodendrocyte plasma membrane. Both monoclonal antibodies also reacted with an antigen that appears associated with the axoneme in cilia of ependymal and choroid plexus epithelium. One monoclonal aPS also showed some reactivity with brain vascular endothelium and reacted slightly with mitochondria, while the other aPS did not react with these structures. While the etiology of aPL-associated neurologic disorders remains unclear, our data suggest possible target sites within the CNS with which aPL can react.

Cardiolipin is a normal component of human plasma lipoproteins

Anticardiolipin (anti-CL) antibodies, diagnostic for antiphospholipid antibody syndrome, are associated with increased risks of venous and arterial thrombosis. Because CL selectively enhances activated protein C/protein S-dependent anticoagulant activities in purified systems and because CL is not known to be a normal plasma component, we searched for CL in plasma. Plasma lipid extracts [chloroform/methanol (2:1, vol/vol)] were subjected to analyses by using TLC, analytical HPLC, and MS. A plasma lipid component was purified that was indistinguishable from reference CL (M:1448). When CL in 40 fasting plasma lipid extracts (20 males, 20 females) was quantitated by using HPLC, CL (mean +/- SD) was 14.9 +/- 3.7 microgram/ml (range 9.1 to 24.2) and CL was not correlated with phosphatidylserine (3.8 +/- 1.7 microgram/ml), phosphatidylethanolamine (64 +/- 20 microgram/ml), or choline-containing phospholipid (1,580 +/- 280 microgram/ml). Based on studies of fasting blood donors, CL (>/=94%) was recovered in very low density, low density, and high density lipoproteins (11 +/- 5.3%, 67 +/- 11.0%, and 17 +/- 10%, respectively), showing that the majority of plasma CL (67%) is in low density lipoprotein. Analysis of relative phospholipid contents of lipoproteins indicated that high density lipoprotein is selectively enriched in CL and phosphatidylethanolamine. These results shows that CL is a normal plasma component and suggest that the epitopes of antiphospholipid antibodies could include CL or oxidized CL in lipoproteins or in complexes with plasma proteins (e. g., beta(2)-glycoprotein I, prothrombin, protein C, or protein S) or with platelet or endothelial surface proteins.

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.

Mitogen-induced cytokine responses of maternal peripheral blood lymphocytes indicate a differential Th-type bias in normal pregnancy and pregnancy failure

PROBLEM

Profiles of Th1- and Th2-type cytokines were studied in women with a history of successful pregnancy and in women with a history of unexplained recurrent spontaneous abortions (RSA) with the objective of elucidating Th1- and Th2-type bias in normal pregnancy and pregnancy failure.

METHOD OF STUDY

Peripheral blood mononuclear cells (PBMCs) from 54 women with a history of normal pregnancy and 23 women with a history of unexplained RSA, obtained at delivery or on the day of abortion, respectively, were stimulated with phytohemagglutinin (PHA), followed by the estimation of four Th2 cytokines and four Th1 cytokines.

RESULTS

Significantly greater levels of Th2 cytokines were produced by the normal group than by the RSA group. On the other hand, significantly higher levels of Th1 cytokines were produced by the RSA group than by the normal pregnancy group.

CONCLUSIONS

These data support the concept that unexplained recurrent spontaneous abortion is associated with an increase in Th1-type reactivity, while Th2 dominance is a feature of successful pregnancy.

Immunological abnormalities in primary APS evolving into SLE: 6 years follow-up in women with repeated pregnancy loss

We have performed a prospective study to determine the prevalence of immunological abnormalities and the evolution from primary antiphospholipid syndrome (APS) into systemic lupus erythematosus (SLE) in women who had had unexplained repeated pregnancy loss (PL) and APS. Of 105 women with abortions or fetal deaths, 33(31%) fulfilled criteria for APS. Among these patients with primary APS, 24% had antinuclear antibodies (ANA), 91% had elevated circulating immune complexes (CIC), 70% had low total haemolytic complement (CH100), 52% had low levels of complement 4 (C4) and 30% had low levels of complement 3 (C3), in a significantly higher prevalence than women whose pregnancies were successful (control group). Through out a 6 y follow-up, 3 (9%) of the patients with APS who had autoimmune related abnormalities when entered into the study developed features of lupus like disease (LLD) or fullblown SLE. Our findings suggest that women with unexplained repeated PL with APS who presented with positive ANA, high levels of CIC, low levels of CH100, C3 and C4, may define a subset of patients exhibiting immunological alterations similar to those of SLE. These parameters may help in the assessment of prognosis in APS patients with PL. Those patients should be carefully surveyed with regard to the development of connective tissue diseases.

Anti-cardiolipin antibody and anti-cardiolipin beta-2-glycoprotein I antibody in patients with recurrent fetal miscarriage

To elucidate the association between anticardiolipin antibody (aCL-Ab) or anti-cardiolipin beta-2-glycoprotein I-antibody (aCL-beta-2-GP I-Ab) and recurrent fetal miscarriage, the positive rates of aCL-Ab were assessed in 667 patients with recurrent fetal miscarriages and those of aCL-beta-2-GP I-Ab were assessed in 208 patients. The rates were then compared with the control group. The positive rate of aCL-Ab in the patients group (17.4%) was significantly higher than that in the control group (4.0%). The rate of aCL-Ab was especially high in patients who had experienced two or more fetal miscarriages including at least one or more intrauterine fetal deaths during the second or third trimester (41.3%). The positive rate of aCL-beta-2-GP I-Ab in patients with recurrent fetal miscarriage (3/208 cases, 1.4%) was not significantly different from the control group (0/100 cases, 0%). However, the rate of aCL-beta-2-GP I-Ab was significantly higher in patients who had experienced two or more fetal miscarriages including at least one or more intrauterine fetal deaths during the second or third trimester (8.3%) compared with the control group. In conclusion, the implication of aCL-Ab in the genesis of recurrent fetal miscarriage was confirmed. It was suggested that aCL-beta-2-GP I-Ab was associated with the generation of intrauterine fetal death, although it had little association with the genesis of recurrent fetal miscarriage during the first trimester.

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.

Echinococcus granulosus human infection stimulates low avidity anticarbohydrate IgG2 and high avidity antipeptide IgG4 antibodies

Total IgG and IgG subclasses recognizing carbohydrate and peptidic epitopes from native and periodate treated partially purified hydatid cyst fluid (ppHCFA) and protoscolex somatic antigens (PSA) were tested by ELISA in hydatid patients sera. Binding of the major cross-reactive antiphosphorylcholine antibodies was inhibited with free reagent. A predominant anticarbohydrate antibody response against ppHCFA and PSA is shown. Although the main contributing IgG subclass to the antipeptide response against both antigens was IgG4, IgG1 also significantly contributed to the anti-PSA peptidic epitopes response. Western blot showed that IgG1 antibodies strongly recognized in ppHCFA a periodate susceptible 38 kDa antigen. The IgG4 antibodies mainly recognized the periodate-resistant 12, 16 and 24 kDa antigens. In addition, IgG2 antibodies recognized three strongly periodate-susceptible broad bands (116, 55 and 24 kDa antigens). PSA-specific IgG1 and IgG4 antibodies showed similar patterns of antigen recognition as well as no significant reduction of reactivity after periodate treatment while the IgG2 antibody recognition was strongly affected by this treatment. Furthermore, IgG2 showed significantly lower avidities than IgG1 and IgG4 antibodies recognizing both antigens. In conclusion, hydatid patients showed an enhanced production of low avidity anticarbohydrate IgG2 as well as high avidity antipeptide IgG4 antibodies.

Vascular complications of diabetes mellitus: what role for phospholipid-binding antibodies?

Vascular complications are the main cause of morbidity in diabetes mellitus. However, the risk factors for vascular disease remain incompletely elucidated. It has been previously suggested that factors other than glycemia may contribute to the development of vasculopathy. In this study we determined the prevalence of phospholipid-binding antibodies in uncomplicated and complicated diabetes. We studied 53 uncomplicated diabetic patients, with type 1 (n = 32) or type 2 (n = 21) diabetes; 23 diabetic patients with proliferative retinopathy; 28 diabetic patients with an overt nephropathy; 37 diabetic patients with macroangiopathy and 22 non diabetic control patients. Both lupus anticoagulant and anticardiolipin antibodies were determined. Other risk factors for macroangiopathy were analysed. The prevalence of phospholipid-binding antibodies was similar in uncomplicated diabetic patients and in controls (type 1 diabetes: 9.4%; type 2 diabetes: 9.5%; control group: 4.6%; P= 0.76). In complicated diabetes, the frequency of these antibodies was increased only in patients with overt nephropathy (32.1%, P=0.01) or with macroangiopathy (32.4%, P=0.01) while patients with isolated retinopathy were comparable with uncomplicated diabetic patients (4.3%, P= 0.66). Uncomplicated diabetes was not associated with phospholipid-binding antibodies. We found a higher prevalence of these antibodies in diabetic patients with macroangiopathy or nephropathy. These results suggest a potential role of phospholipid-binding antibodies in the progression of vascular complications in diabetes mellitus.

Antiphospholipid Antibodies Accelerate Plasma Coagulation by Inhibiting Annexin-V Binding to Phospholipids: A “Lupus Procoagulant” Phenomenon

The antiphospholipid syndrome is a thrombophilic condition marked by antibodies that recognize anionic phospholipid-protein cofactor complexes. We recently reported that exposure to IgG fractions from antiphospholipid patients reduces the level of annexin-V, a phospholipid-binding anticoagulant protein, on cultured trophoblasts and endothelial cells and accelerates coagulation of plasma exposed to these cells. Therefore, we asked whether antiphospholipid antibodies might directly reduce annexin-V binding to noncellular phospholipid substrates. Using ellipsometry, we found that antiphospholipid IgGs reduce the quantity of annexin-V bound to phospholipid bilayers; this reduction is dependent on the presence of β2-glycoprotein I. Also, exposure to plasmas containing antiphospholipid antibodies reduces annexin-V binding to phosphatidyl serine-coated microtiter plates, frozen thawed washed platelets, activated partial thromboplastin time (aPTT) reagent and prothrombin time reagent and reduces the anticoagulant effect of the protein. These studies show that antiphospholipid antibodies interfere with the binding of annexin-V to anionic phospholipid and with its anticoagulant activity. This acceleration of coagulation, due to reduced binding of annexin V, stands in marked contrast to the “lupus anticoagulant effect” previously described in these patients. These results are the first direct demonstration of the displacement of annexin-V and the consequent acceleration of coagulation on noncellular phospholipid surfaces by antiphospholipid antibodies.

© 1998 by The American Society of Hematology.

Antiphospholipid Antibodies Accelerate Plasma Coagulation by Inhibiting Annexin-V Binding to Phospholipids: A “Lupus Procoagulant” Phenomenon

The antiphospholipid syndrome is a thrombophilic condition marked by antibodies that recognize anionic phospholipid-protein cofactor complexes. We recently reported that exposure to IgG fractions from antiphospholipid patients reduces the level of annexin-V, a phospholipid-binding anticoagulant protein, on cultured trophoblasts and endothelial cells and accelerates coagulation of plasma exposed to these cells. Therefore, we asked whether antiphospholipid antibodies might directly reduce annexin-V binding to noncellular phospholipid substrates. Using ellipsometry, we found that antiphospholipid IgGs reduce the quantity of annexin-V bound to phospholipid bilayers; this reduction is dependent on the presence of β2-glycoprotein I. Also, exposure to plasmas containing antiphospholipid antibodies reduces annexin-V binding to phosphatidyl serine-coated microtiter plates, frozen thawed washed platelets, activated partial thromboplastin time (aPTT) reagent and prothrombin time reagent and reduces the anticoagulant effect of the protein. These studies show that antiphospholipid antibodies interfere with the binding of annexin-V to anionic phospholipid and with its anticoagulant activity. This acceleration of coagulation, due to reduced binding of annexin V, stands in marked contrast to the “lupus anticoagulant effect” previously described in these patients. These results are the first direct demonstration of the displacement of annexin-V and the consequent acceleration of coagulation on noncellular phospholipid surfaces by antiphospholipid antibodies.

© 1998 by The American Society of Hematology.

Antiphospholipid antibodies associated with implantation failure after IVF/ET

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Pathogenic antibodies in women with obstetric features of antiphospholipid syndrome who have negative test results for lupus anticoagulant and anticardiolipin antibodies

OBJECTIVE

Our goal was to determine whether women with clinical features of antiphospholipid syndrome but negative test results for lupus anticoagulant and anticardiolipin antibodies have pathogenic antibodies not identified by currently used methods.

STUDY DESIGN

Sera were obtained from women with clinical features associated with antiphospholipid antibodies who had negative test results for lupus anticoagulant and anticardiolipin antibodies (antiphospholipid syndrome-like). We studied (1) the effect of passive immunization with their purified immunoglobulin G fraction on murine pregnancy (n = 35) and (2) the presence of antiphospholipid antibodies other than lupus anticoagulant or anticardiolipin antibodies (n = 39). Sera were also retested for anticardiolipin antibodies and lupus anticoagulant.

RESULTS

Fetal loss occurred in 235 of 1088 (22%) pups in 137 mice immunized with immunoglobulin G fraction from antiphospholipid syndrome-like women compared with 23 of 402 (6%) pups in 53 control mice. Immunoglobulin G from 11 study patients resulted in the loss of at least one third of the exposed pups. Five women had positive levels of antiphosphatidylserine antibodies (>99th percentile). All levels were low positive, and three women also had low-positive levels of anticardiolipin antibodies on repeat testing. Five of the 11 (45%) women whose immunoglobulin G fractions caused at least 33% fetal loss also had positive test results for antiphospholipid antibodies.

CONCLUSIONS

A subset of women with clinical disorders suspicious for antiphospholipid syndrome but who had negative test results for lupus anticoagulant and anticardiolipin antibodies by current methods have serum immunoglobulin G that is pathogenic to murine pregnancy. Testing for pathogenic immunoglobulin G may provide additional means to identify women with an as yet uncharacterized immune condition. The clinical relevance of low levels of antiphospholipid antibodies in these women remains unproved.

Antiphospholipid antibodies in healthy pregnant women

This article discusses the prevalence and clinical significance of antiphospholipid antibodies (aPL) in the normal, healthy pregnant population. Although an increased risk for adverse fetal outcome has been shown in a small subset of this population, most pregnancies in aPL-positive mothers have successful outcomes. We review the variations in aPL levels during pregnancy and consider screening strategies and therapeutic interventions in healthy aPL-positive pregnant women.

Recurrent fetal loss and antiphospholipid antibodies: clinical and therapeutic aspects

Recurrent fetal losses indicate screening for antiphospholipid antibodies, especially after the third consecutive fetal loss, or when they occur after 12 weeks gestation or when the mother presents with thrombosis or other ailments of antiphospholipid syndrome. Fetal loss may be caused by thromboses of placental vasculature. There is no agreement concerning the mechanism of thromboses: protein C pathway and/or annexin V are the best candidates. When fetal loss occurs early during gestation, murine models suggest that antiphospholipid antibodies can also act on trophoblasts by inhibiting syncytia formation. Among the high risk patients with more than two fetal losses, an association of aspirin and heparin given early during gestation is successful in 70–80% of cases.

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 antibody-associated recurrent pregnancy loss: treatment with heparin and low-dose aspirin is superior to low-dose aspirin alone

OBJECTIVE

The purpose of this study was to compare the use of low-dose aspirin alone with heparin and low-dose aspirin in the treatment of the antiphospholipid antibody syndrome.

STUDY DESIGN

A prospective, single-center trial included 50 patients who were alternately assigned to treatment. Each patient had at least three consecutive spontaneous pregnancy losses, positive antiphospholipid antibodies on two occasions, and a complete evaluation. Data were compared by chi(2) analysis and Fisher's exact test.

RESULTS

Viable infants were delivered of 11 of 25 (44%) women treated with aspirin and 20 of 25 (80%) women treated with heparin and aspirin (p < 0.05). There were no significant differences between the low-dose aspirin and the heparin plus low-dose aspirin groups with respect to gestational age at delivery (37.8 +/- 2.1 vs 37.2 +/- 3.4 weeks), number of cesarean sections (18% vs 20%), or complications.

CONCLUSION

Heparin plus low-dose aspirin provides a significantly better pregnancy outcome than low-dose aspirin alone does for antiphospholipid antibody-associated recurrent pregnancy loss.

A clinical trial for the treatment of antiphospholipid antibody-associated recurrent pregnancy loss with lower dose heparin and aspirin

This study was conducted to determine if lower dose heparin (LD Heparin) combined with aspirin is as efficacious as higher dose heparin (HD Heparin) for the treatment of the antiphospholipid antibody syndrome in women seeking pregnancy. The method of the study was a prospective, single center trial including 50 patients who were consecutively assigned to treatment. Each patient had at least three consecutive, spontaneous pregnancy losses, positive antiphospholipid antibodies on two occasions, and a complete evaluation. Data were compared using Fisher's exact test. Viable infants were delivered from 20/25 (80%) women treated with higher dose heparin vs. 19/25 (76%) of women treated with lower dose heparin. There were no significant differences between groups with respect to gestational age at the time of delivery (37.2 +/- 3.4 versus 37.7 +/- 1.6 weeks), maternal complications, or fetal complications. A lower dose of heparin plus aspirin was as effective as higher dose heparin for the treatment of antiphospholipid antibody-associated recurrent pregnancy loss.

Antiphospholipid antibody prevalence in patients with IVF failure

Antiphospholipid antibodies (APAs) have been associated with reproductive wastage. The purpose of this study was to establish the prevalence of APAs in women who have had at least 12 embryos transferred during several in vitro fertilization (IVF) cycles without ensuing pregnancy. Sera from 42 women with IVF failure and 42 women who successfully conceived after IVF were tested for the presence of APAs by ELISA. Successful post-IVF pregnancy was determined by obtaining two consecutive rising beta-hCG levels followed by an ultrasound to confirm a viable conceptus. The sera were tested for three isotypes of antibody: IgA, IgG, and IgM against seven phospholipids: cardiolipin (CL), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidic Acid (PA), phosphatidyl-glycerol (PG), phosphatidylcholine (PC), and phosphatidyl-serine (PS). From the IVF failure group, 11/42 (26.2%) were positive for APAs. From the control group, 2/42 (4.8%) were found positive only for IgA against PE. The difference between IVF failure and successful IVF groups was significant (P = 0.01). These results suggest that antiphospholipid antibodies should be considered an important marker for increased risk of IVF failure. Patients who are involved with an IVF program should be tested for the presence of APAs prior to initiation of an IVF cycle.