Preconception antiphospholipid antibodies and risk of subsequent early pregnancy loss.

Objectives To prospectively estimate the association of preconception antiphospholipid antibodies (aPL) with subsequent pregnancy loss using a cohort design. aPL have been associated with recurrent early pregnancy loss (EPL) prior to 10 weeks in previous case-control studies. Prospective ascertainment of pregnancy loss is challenging, as most women do not seek care prior to EPL. Methods Secondary analysis of the Effects of Aspirin in Gestation and Reproduction trial of preconception low-dose aspirin. Preconception anticardiolipin (aCL) and anti-ß2-glycoprotein-I (a-ß2-I) were assessed in 1208 women with one or two prior pregnancy losses and no more than two prior live births. Comparison cohorts were defined by positive aPL (+aPL) or negative aPL (-aPL) status. All women were followed for six menstrual cycles while trying to conceive; if successful, they underwent an ultrasound at 6-7 weeks' gestation. EPL was defined as loss prior to 10 weeks' gestation; embryonic loss was loss after visualization of an embryo but prior to 10 weeks; clinical loss was any loss after visualization of an embryo (with or without fetal cardiac activity detected). Results In total, 14/1208 (1%) tested positive for +aPL. 786/1208 (65%) women had positive human chorionic gonadotropin during the study period, of which 9/786 (1%) had +aPL. Of the 786 pregnant women, 589 (75%) had live births and 24% had pregnancy losses. Women with +aPL experienced EPL at similar rates as women with -aPL, 44% vs 21% (aRR 2.4, 95% confidence interval (CI) 0.5-10.9). Embryonic loss was more common in women with +aCL IgM (aRR 4.8, 95% CI 1.0-23.0) and in women with two positive aPL. Clinical pregnancy loss was more common in women with positive a-ß2-I IgM (50% vs 16.5%, aRR 3.7, 95% CI 1.3-10.8). Conclusion Positive levels of aPL are rare in women with one or two prior pregnancy losses and are not clearly associated with an increased rate of subsequent loss. Clinical trial registration The original source study was registered at ClinicalTrials.gov (#NCT00467363).

Beta2-glycoprotein I can exist in 2 conformations: implications for our understanding of the antiphospholipid syndrome.

The antiphospholipid syndrome is defined by the presence of antiphospholipid antibodies in blood of patients with thrombosis or fetal loss. There is ample evidence that beta(2)-glycoprotein I (beta(2)GPI) is the major antigen for antiphospholipid antibodies. The autoantibodies recognize beta(2)GPI when bound to anionic surfaces and not in solution. We showed that beta(2)GPI can exist in at least 2 different conformations: a circular plasma conformation and an "activated" open conformation. We also showed that the closed, circular conformation is maintained by interaction between the first and fifth domain of beta(2)GPI. By changing pH and salt concentration, we were able to convert the conformation of beta(2)GPI from the closed to the open conformation and back. In the activated open conformation, a cryptic epitope in the first domain becomes exposed that enables patient antibodies to bind and form an antibody-beta(2)GPI complex. We also demonstrate that the open conformation of beta(2)GPI prolonged the activated partial thromboplastin time when added to normal plasma, whereas the activated partial thromboplastin time is further prolonged by addition of anti-beta(2)GPI antibodies. The conformational change of beta(2)GPI, and the influence of the autoantibodies may have important consequences for our understanding of the antiphospholipid syndrome.

Plasma exchange and immunoadsorption effectively remove antiphospholipid antibodies in pregnant patients with antiphospholipid syndrome.

Conventional therapy with aspirin and/or heparin is at times incapable of preventing complications in high risk pregnancies of patients with antiphospholipid syndrome (APS). In those cases, a so-called second-line treatment protocol is used in addition to conventional therapy strategies. This manuscript is a report on three APS pregnant patients who were successfully treated with plasma exchange (PE) (two cases) or with immunoadsorption (IA) (one case) as a second-line treatment strategy. The efficacy of these procedures in removing anticardiolipin (aCL) and anti-ß(2)glycoprotein I (aß(2)GPI) antibodies from blood was evaluated. Serum samples were collected before and after 87 apheretic treatment sessions. Serum IgG/M aCL and IgG/M aß(2)GPI antibodies were determined using an "in-house" enzyme-linked immunosorbent assay and showed that all three patients had medium/high IgG aCL and aß(2)GPI titers. All three women had a successful pregnancy. A significant decrease in IgG aCL (P = 0.0001) and aß(2)GPI (P = 0.0001) antibody titers was observed after PE and IA sessions. There was moreover a significant, steady fall in serum IgG aCL pretreatment levels during the course of all three pregnancies (P = 0.0001, P = 0.0001, P = 0.001). The fall in IgG aß(2)GPI was significant in two of the patients (P = 0.0001, P = 0.0001) both with high antibody titers, but not in one with medium antibody titers, who was treated with PE (P = 0.17).

The antiphospholipid syndrome: an update.

Antiphospholipid syndrome is an autoimmune disorder defined by the association between antiphospholipid antibodies (i.e., lupus anticoagulant and anticardiolipin antibodies) and venous or arterial thrombosis or obstetric complications. In spite of the recent advances, many aspects of this disease remain unclear. Although the antigenic targets of this heterogeneous group of autoantibodies have been determined, being negatively charged phospholipids-binding proteins, their precise pathogenic mechanism is still being determined. The most important advances in the pathophysiology, diagnosis and treatment of this condition are discussed in this review.

[New insights into the pathogenicity of antiphospholipid antibodies].

Antiphospholipid antibodies (aPL) recognize phospholipid-binding proteins such as beta(2)-glycoprotein I (beta(2)-GPI) and prothrombin, inducing thrombosis and pregnancy morbidities. Pathogenicity of aPL has been established by many in vivo experiments in which administration of aPL resulted in pregnancy losses and/or thrombotic phenomena. The mechanisms how aPL cause such symptoms have been extensively investigated. aPL alters fibrinolysis/coagulation system by suppression of protein C/Z systems in the presence of beta(2)-GPI. B cell epitopes were also studied for specific therapies, resulting in diverse candidates such as domain I, IV or other domains. For T cells, importance of cryptic epitope on domain V was suggested. Recently, activation of endothelial cells, monocytes and thrombocytes by aPL with beta(2)-GPI has been reported. This activation is mainly mediated by p38MAP kinase activation and results in expression of tissue factor and adhesion molecules in endothelial cells and monocytes, thromboxane B2 in thrombocytes. Annexin II, toll-like receptor 4, LDL-receptor family members, and glycoprotein Ib are the candidates for cell surface ligands, suggesting the possibility of their blockades by monoclonal antibodies. Although treatment of APS is now limited to nonspecific anticoagulants or anti-platelet agents, based on these new insights, specific therapies targeting signal molecules and/or cell surface ligands for beta(2)-GPI should be introduced in near future.

Measuring IgA Anti-ß2-Glycoprotein I and IgG/IgA Anti-Domain I Antibodies Adds Value to Current Serological Assays for the Antiphospholipid Syndrome.

INTRODUCTION: Currently available clinical assays to detect antiphospholipid antibodies (aPL) test for IgG and IgM antibodies to cardiolipin (aCL) and ß2-glycoprotein I (aß2GPI). It has been suggested that testing for IgA aPL and for antibodies to Domain I (DI), which carries the key antigenic epitopes of ß2GPI, could add value to these current tests. We performed an observational, multicenter cohort study to evaluate the utility of IgG, IgM and IgA assays to each of CL, ß2GPI and DI in APS. METHODS: Serum from 230 patients with APS (n = 111), SLE but not APS (n = 119), and 200 healthy controls were tested for IgG, IgM and IgA aCL, aß2GPI and aDI activity. Patients with APS were further classified into thrombotic or obstetric APS. Logistic regression and receiver operator characteristic analyses were employed to compare results from the nine different assays. RESULTS: All assays displayed good specificity for APS; IgG aCL and IgG aß2GPI assays however, had the highest sensitivity. Testing positive for IgA aß2GPI resulted in a higher hazard ratio for APS compared to IgM aß2GPI. Positive IgG, IgM or IgA aDI were all associated with APS, and in subjects positive for aCL and/or aß2GPI, the presence of aDI raised the hazard ratio for APS by 3-5 fold. IgG aCL, aß2GPI, aDI and IgA aDI were associated with thrombotic but not obstetric complications in patients with APS. CONCLUSION: Measuring IgG aDI and IgA aß2GPI and aDI may be useful in the management of patients with APS, particularly thrombotic APS.

Purified IgG from patients with obstetric but not IgG from non-obstetric antiphospholipid syndrome inhibit trophoblast invasion.

PROBLEM: Some patients with antiphospholipid syndrome (APS) suffer pregnancy morbidity (PM) but not vascular thrombosis (VT), whilst others suffer VT only. Therefore, we compared the effects of IgG from VT+/PM- and VT-/PM+ subjects on human first-trimester trophoblast (HTR8) cells. METHOD OF STUDY: HTR-8 cells were incubated with APS VT+/PM-, APS VT-/PM+ or healthy control (HC) IgG. We measured trophoblast invasion by cell invasion assay; mRNA expression of TLR4 and adaptor proteins; phosphorylation of p38 MAPK, NFκB and ERK; and expression of interleukin (IL)-8 and IL-6. RESULTS: VT-/PM+ IgG, but not VT+/PM- IgG significantly reduced HTR-8 invasion. The effects on invasion were blocked by TLR-4 inhibition. Neither VT+/PM- nor VT-/PM+ IgG altered MyD88 mRNA expression, phosphorylation of signalling molecules or cytokine expression. CONCLUSIONS: VT-/PM+ IgG exert functionally relevant effects on human trophoblast cells but VT+/PM- IgG do not.

E-Selectin mediates pathogenic effects of antiphospholipid antibodies.

Antiphospholipid (aPL) antibodies, detected in patients with antiphospholipid syndrome (APS) are associated with thrombosis, pregnancy loss and thrombocytopenia. Studies have shown that aPL are thrombogenic in vivo, but the mechanism(s) involved are not completely understood. Several studies have demonstrated that aPL antibodies activate endothelial cells (ECs) in vitro, as determined by up-regulation of adhesion molecules: E-selectin (E-sel); intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), and in vivo. The objectives of these study were to determine the effects of aPL antibodies on the expression of E-selectin on ECs, on the adhesion of monocytes to ECs and to study the role of E-selectin on aPL antibodies enhanced thrombus formation and activation of ECs in vivo. We demonstrated that the surface expression of E-selectin on HUVEC by ELISA was increased 400-fold when treated with tumor necrosis factor-alpha (TNF-alpha) and 421-fold when treated with aPL antibodies during 4 h. APL antibodies also induced activation of the nuclear factor-kappa B (NF-kappaB). APL antibodies increased significantly the number of adhering leukocytes to ECs in vivo in C57BL/6 J mice when compared to IgG-NHS treated mice. This effect was abrogated in E-selectin-deficient mice. The thrombus size was significantly increased in C57BL/6 J mice treated with aPL antibodies when compared to mice treated with IgG-NHS. This enhancement in thrombus size by aPL antibodies was abrogated in E-selectin-deficient mice treated with aPL antibodies.

Comparison of the primary and secondary antiphospholipid syndrome: a European Multicenter Study of 114 patients.

PURPOSE: To determine whether the features of the antiphospholipid syndrome (APS) are in any way influenced by the presence or absence of systemic lupus erythematosus (SLE). We followed up patients with 'primary' APS (PAPS) and APS secondary to SLE (APS plus SLE) with the objective of comparing laboratory and clinical events and of determining whether patients with PAPS would have evolution to SLE. PATIENTS AND METHODS: A total of 114 patients from 3 European referral centers were included in this study. Fifty-six had APS plus SLE and 58 had PAPS. Laboratory and clinical data were collected during an average 2-year period. RESULTS: Patients with PAPS and patients with APS plus SLE had similar clinical and laboratory profiles, with the exceptions of autoimmune hemolytic anemia, endocardial valve disease, neutropenia, and low C4 levels, all of which occurred more frequently in patients with APS plus SLE (p values: < 0.05, < 0.005, < 0.01, and < 0.001, respectively). On follow-up, 10 thrombotic episodes occurred in 10 patients, 8 of whom were receiving anticoagulant therapy. No patient with PAPS had either anti-DNA or anti-extractable nuclear antigen antibodies, and these patients had a significantly lower prevalence of antinuclear antibodies (41%) than patients with APS plus SLE (89%). CONCLUSIONS: Patients with APS plus SLE and PAPS have similar clinical profiles, although heart valve disease, hemolytic anemia, low C4 levels, and neutropenia seem to be more common in patients with APS plus SLE. Patients with APS may develop further thrombotic events despite anticoagulation therapy.

Analysis of prothrombotic effects of two human monoclonal IgG antiphospholipid antibodies of apparently similar specificity.

Two human monoclonal antiphospholipid antibodies (APA) of the IgG type, HL-5B and RR-7F have been generated from a patient with primary antiphospholipid syndrome and recurrent cerebral microemboli (H.L.) and from a patient with SLE without evidence of recurrent thrombosis (R.R.). Both monoclonal APA have similar characteristics in ELISA tests. To further analyse the prothrombotic potential, their effect on human monocytes and platelets, and bovine aortic endothelial cells (BAEC) was investigated. Monocytes were isolated from buffy coats by standard techniques. They were incubated either with the respective monoclonal APA in different concentrations, or a control monoclonal IgG of the same subtype, or plasma of the patients, from whom the antibodies were isolated. Incubation with LPS served as positive control. BAEC were grown to confluence, and then incubated with the appropriate agonists. Procoagulant activity (PCA) was determined by a single stage clotting assay. PCA expression after incubation is given as the ratio of the coagulation times observed with media only divided by that observed with the agonist. A PCA ratio >1 indicates the induction of PCA by the agonist. At 1 microg/ml HL-5B yielded a PCA ratio of 1.63 +/- 0.16 while RR-7F induced no significant rise to 1.06 +/- 0.18. Dose response curves showed that RR-7F can induce PCA at higher concentrations. However, its effect is approx. 1/50 of HL-5B based on equimolar antibody concentration. Further analysis indicates that the majority of the PCA induced by monoclonal APA can be inhibited by a specific tissue factor antibody. Neither monoclonal antibody induced PCA in BAEC. Sera from both patients were able to induce PCA in monocytes. However, the PCA ratio of serum from H.L. was higher (1.78) than that of R.R. (1.44). Neither monoclonal APA had an effect on platelets as determined by flow cytometric analysis of CD62P, CD41, CD42b expression and fibrinogen binding with and without previous activation with 5 microM ADP or 15 microM TRAP-6. Similarly, there were no differences in platelet aggregation to different stimuli including submaximal activation. In summary, these data provide further evidence that induction of tissue factor in monocytes is one of the procoagulant effects of APA. Furthermore, the binding specificity of APA is perhaps not suited to predict the biological effects of the antibodies.

Antiphospholipid antibody production during Mediterranean spotted fever.

Antiphospholipid antibodies (aPLA) were discovered during the course of Mediterranean spotted fever (MSF) caused by Rickettsia conorii and characterized by endothelial cell (EC) damage resulting from this organism's tropism for EC. In two MSF patients, two types of aPLA were identified: antiphosphatidylethanolamine antibodies detected by immunological methods and lupus anticoagulant detected by clotting assays. The persistence of both aPLA for several months after the acute phase and clinical recovery might correspond to a durable immunological response to membrane damage of EC caused by R. conorii. Their possible role in the pathophysiology of microthrombi formation observed during MSF remains to be elucidated in a study on a larger number of patients.

Origin and pathogenesis of antiphospholipid antibodies.

Antiphospholipid antibodies (aPL) are a heterogeneous group of antibodies that are detected in the serum of patients with a variety of conditions, including autoimmune (systemic lupus erythematosus), infectious (syphilis, AIDS) and lymphoproliferative disorders (paraproteinemia, myeloma, lymphocytic leukemias). Thrombosis, thrombocytopenia, recurrent fetal loss and other clinical complications are currently associated with a subgroup of aPL designating the antiphospholipid syndrome. In contrast, aPL from patients with infectious disorders are not associated with any clinical manifestation. These findings led to increased interest in the origin and pathogenesis of aPL. Here we present the clinical features of the antiphospholipid syndrome and review the origin of aPL, the characteristics of experimentally induced aPL and their historical background. Within this context, we discuss the most probable pathogenic mechanisms induced by these antibodies.

Systemic lupus erythematosus with sensorineural hearing loss and improvement after plasmapheresis using the double filtration method.

A 32-year-old female was diagnosed as having systemic lupus erythematosus based on her laboratory tests. In 1985 she began to complain of hearing difficulty. Her hearing ability deteriorated to the extent that her audiogram revealed a hearing loss of 90 db to 110 db in both ears in September 1989. She received two series of plasmapheresis treatments using the double filtration method. After two series of plasmapheresis treatments, her hearing improved dramatically. This improvement suggests that circulating immune complexes and anti-phospholipid antibodies might play a pathological role in the hearing impairment in SLE patient.

[Isolated memory disorders disclosing antiphospholipid antibody syndrome]. / Troubles mnésiques isolés révélant un syndrome des anticorps anti-phospholipides.

Most of the neurological complications of the antiphospholipid syndrome are consequences of arterial or venous cerebral thromboses. We report the case of a 46-year-old woman presenting with the main signs of antiphospholipid syndrome: Raynaud's phenomenon, livedo, leg ulcers, repeated miscarriages, presence of a circulating anticoagulant and of antiphospholipid antibodies, who developed an isolated amnestic syndrome with a peculiar pattern; 1) almost complete sparing of the ability to learn new skills and of short-term recall; 2) deterioration, followed by disappearance of recent memories after a sufficient delay; 3) progressive alteration of increasingly old memories including knowledge memory suggested a gradual alteration of mnestic traces. The lack of neuroradiological signs of multiple infarcts suggests a direct intervention of antibodies in this patient's memorisation mechanisms.

[Antiphospholipid antibodies in 66 patients with cerebral infarction between 15 and 40 years old]. / Anticorpos antifosfolípides em 66 pacientes com infarto cerebral entre 15 e 40 anos.

The antiphospholipid antibodies (aPLs) are a heterogeneous group of immunoglobulins that have been related with alterations in blood coagulability in recent years. Patients with elevated titers of these antibodies have a high probability to develop thrombotic events, including cerebral infarct (CI). The tests currently used to detect these antibodies are the lupus anticoagulant and ELISA for anticardiolipin antibodies which have a larger proportion of positivity among young patients with CI. In our study we tested 66 patients with cerebral infarcts whose ages ranged from 15 to 40 years for the presence of lupus anticoagulant and anticardiolipin antibodies. The results showed that eleven (16.65%) patients were positive for aPLs and three (4.55%) of them fulfilled the diagnostic criteria for primary antiphospholipid syndrome. These data point out to the importance of investigating aPLs in young patients with CI and its high prevalence in this group compared with healthy population.

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

CONTEXT: Patients with antiphospholipid syndrome and alloimmunity have poor pregnancy outcomes. Several diagnostic and therapeutic options exist for these disorders, although there is no consensus as to the best treatment. CASE REPORT: We present here the clinical course and treatment of a woman with a history of two miscarriages who joined our program 10 years ago and has been followed up ever since. After antiphospholipid syndrome and alloimmune failure were diagnosed, she was given preconceptional treatment using unfractionated heparin, aspirin, prednisone and lymphocyte immunizations. She delivered two premature babies in the following two pregnancies. At present both children are healthy and are attending school. The fifth pregnancy was unsuccessful, in spite of having undergone a similar but postconceptional therapeutic scheme. We discuss this case focusing on the pathogenic mechanisms and the therapeutic aspects of these disorders.

Sneddon's syndrome with bilateral peripheral retinal neovascularization.

A 27-year old woman is presented with a five year old history of Sneddon's syndrome in whom recently peripheral retinal neovascularization in both eyes was discovered. Sneddon's syndrome is a rare clinical entity first described in 1965 and characterized by typical skin lesions (livedo reticularis) and cerebrovascular lesions occurring at early age. Central retinal artery occlusions have been reported twice in Sneddon-patients, but peripheral retinal capillary occlusions and neovascularization have not yet been reported. The role of the antiphospholipid antibodies in this association is discussed.

Anti-beta2-glycoprotein I antibodies as risk factors for acute myocardial infarction.

OBJECTIVE: To determine whether high levels of antibodies against the phospholipid beta2-glycoprotein I (beta2-gpI) cofactor are associated with an increase in the risk of acute myocardial infarction. METHODS: The study comprised 82 patients with acute myocardial infarction and 82 controls, who were assessed in regard to age, sex, race, hypertension, smoking, previous heart disease, history of diabetes mellitus, and hypercholesterolemia. The following antibodies were detected using immunoassay: anticardiolipin and anti-beta2-gpI IgA, IgG, and IgM. Adjusted odds ratios (OR) for risk factors were obtained through logistic regression. RESULTS: The mean ages of the cases and controls were, respectively, 57.7 and 51.1 years (P=0.003). Men (P=0.005) and the white race predominated in both groups (P=0.798). Of the risk factors, a history of diabetes (OR=5.3; 95% CI: 1.9 to 14.9; P=0.001) and previous heart disease (OR=4.7; 95% CI: 2.0 to 10.7; P<0.001) were the most consistent associations with myocardial infarction. The frequency of anticardiolipin IgG, IgM, and IgA antibodies did not differ between cases and controls (P=1.000). Anti-beta2-gpI IgA antibodies were more frequent in cases than in controls (P=0.054). The adjusted OR for anti-beta2-gpI IgA antibodies was 3.4 (95% CI: 1.3 to 9.1; P=0.015). CONCLUSION: Anti-beta2-gpI IgA antibodies, but not anticardiolipin antibodies, seemed to behave as independent risk factors for myocardial infarction, which may represent a link between autoimmunity and atherosclerosis in patients with acute myocardial infarction.

[The clinical relevance of autoantibody studies in connective tissue diseases and vasculitis]. / Intérêt clinique de la recherche des autoanticorps dans les connectivites et les vasculites.

The relevance of detection, quantification and characterisation of antinuclear antibodies and of anti-neutrophil cytoplasm antibodies in diagnosis of connective tissue disorders and of idiopathic vasculitis, is nowadays quite important. Since many years, antibody detection is routinely performed by indirect immunofluorescence tests; their sensitivity is very high so that several diagnoses might be ruled out in the presence of a negative result. These tests are however not specific. During the last years several progress have been realised in the characterisation of the antigens recognized by these antibodies, allowing the development of new techniques for specifically identifying several autoantibodies. It is therefore possible to detect now routinely with specific and sensitive techniques the presence of anti-double stranded DNA, anti-RNP, anti-Sm, anti-Scl-70, anti-SS-A, anti-SS-B, and anti-myeloperoxidase and anti-proteinase 3. The significance of the presence of these antibodies in serum will be discussed in this paper.