Detrimental roles of TNF-alpha in the antiphospholipid syndrome and de novo synthesis of antiphospholipid antibodies induced by biopharmaceuticals against TNF-alpha.

Antiphospholipid syndrome (APS) is an autoimmune disease that is characterized by arterial and/or venous thrombosis and/or recurrent pregnancy losses. Obstetric APS (OAPS) is considered as a distinct entity from vascular APS (VAPS). In the absence of any additional disease, APS is designated as primary (PAPS), while the term secondary APS (SAPS) is used when other diseases are associated. Catastrophic APS (CAPS) is characterized by the rapid development of multiple thrombosis in various vital organs. The presence of antiphospholipid antibodies (aPL Abs) is considered as a laboratory criterion for APS diagnosis. aPL Abs cause an increase in systemic and decidual TNF-alpha levels in experimental model of APS (eAPS), while paradoxically, administration of TNF-alpha blockers has been associated with de novo synthesis of aPL Abs in patients with various autoimmune diseases. While eAPS provides evidence for the fact that application of TNF-alpha blockers has beneficial effects, lack of randomized prospective studies is the main obstacle for consideration of TNF-alpha blockers administration as a therapeutic option not for all, but at least for selected cases of APS patients despite compelling evidence for detrimental roles of TNF-alpha for both VASP and OAPS. This article represents a review of previously published reports on detrimental roles of TNF-alpha in APS, reports on the application of anti-TNF-alpha agents in eAPS and articles that reported de novo synthesis of aPL Abs induced by biopharmaceuticals against TNF-alpha.

Diagnostic criteria for systemic lupus erythematosus: a critical review.

Systemic lupus erythematosus is a multi-organ system autoimmune disease with clinical and serological heterogeneity. The formulation of initial criteria for SLE was first proposed by the American College of Rheumatology and appeared in 1971. Although the original purpose of the criteria was to classify the disease, it became widely used as a diagnostic criteria in clinical situations. Since then the ACR criteria have undergone at least two changes (in 1982 and 1997). Clinical manifestations that can differentiate SLE patients from healthy people such as skin lesions, arthritis, renal disorder, neurologic disorder, hematologic changes and others are included in these criteria. Serum anti-nuclear antibody, anti-ds-DNA antibody and anti-Sm antibody are important biomarkers of SLE patients. In 2012, the Systemic Lupus Collaborating Clinics proposed the SLICC criteria for SLE in view of new knowledge of autoantibodies and the importance of low complement. Future biomarkers may be useful in distinguishing SLE from other diseases and in monitoring of disease activity.

Long-term outcome of 32 patients with chorea and systemic lupus erythematosus or antiphospholipid antibodies.

OBJECTIVE: The aim of this work was to describe chorea during systemic lupus erythematosus or antiphospholipid antibodies and its long-term outcome. METHODS: We retrospectively analyzed clinical features, laboratory findings, imaging characteristics, and outcome in a series of 32 patients. RESULTS: Most patients were women (28 of 32), and mean age at onset of chorea was 20.6 (9-62) years. Chorea was inaugural for 28 patients. Improvement was observed with various treatments. During follow-up (12.2 ± 11.3 years), severe manifestations of systemic lupus erythematosus were rare. Antiphospholipid antibodies were repeatedly positive for 90% of the patients. Twelve patients developed arterial thrombosis. Prophylactic treatment with antithrombotic therapy might reduce the risk of further thrombosis (8% versus 57%; P = 0.01). Cardiac valvulopathy occurred in 22 patients during follow-up. Chorea relapsed in 8 cases. CONCLUSIONS: Chorea had a good outcome in itself. This long-term follow-up shows, for the first time, that these patients have substantial risk for further arterial thrombosis.

Lipid presentation by the protein C receptor links coagulation with autoimmunity.

Antiphospholipid antibodies (aPLs) cause severe autoimmune disease characterized by vascular pathologies and pregnancy complications. Here, we identify endosomal lysobisphosphatidic acid (LBPA) presented by the CD1d-like endothelial protein C receptor (EPCR) as a pathogenic cell surface antigen recognized by aPLs for induction of thrombosis and endosomal inflammatory signaling. The engagement of aPLs with EPCR-LBPA expressed on innate immune cells sustains interferon- and toll-like receptor 7-dependent B1a cell expansion and autoantibody production. Specific pharmacological interruption of EPCR-LBPA signaling attenuates major aPL-elicited pathologies and the development of autoimmunity in a mouse model of systemic lupus erythematosus. Thus, aPLs recognize a single cell surface lipid-protein receptor complex to perpetuate a self-amplifying autoimmune signaling loop dependent on the cooperation with the innate immune complement and coagulation pathways.

Antineutrophil properties of natural gingerols in models of lupus.

Ginger is known to have antiinflammatory and antioxidative effects and has traditionally been used as an herbal supplement in the treatment of various chronic diseases. Here, we report antineutrophil properties of 6-gingerol, the most abundant bioactive compound of ginger root, in models of lupus and antiphospholipid syndrome (APS). Specifically, we demonstrate that 6-gingerol attenuates neutrophil extracellular trap (NET) release in response to lupus- and APS-relevant stimuli through a mechanism that is at least partially dependent on inhibition of phosphodiesterases. At the same time, administration of 6-gingerol to mice reduces NET release in various models of lupus and APS, while also improving other disease-relevant endpoints, such as autoantibody formation and large-vein thrombosis. In summary, this study is the first to our knowledge to demonstrate a protective role for ginger-derived compounds in the context of lupus. Importantly, it provides a potential mechanism for these effects via phosphodiesterase inhibition and attenuation of neutrophil hyperactivity.

The high prevalence of antiphospholipid antibodies in refractory focal epilepsy is related to recurrent seizures.

BACKGROUND: Previous studies have shown the association between antiphospholipid antibodies with epilepsy but there are no studies addressing the effect of seizure frequency, duration of epilepsy, epilepsy type and aetiology on the prevalence of these antibodies in well-evaluated refractory epilepsy. METHODS: Anticardiolipin, anti-beta2-glycoprotein I and antinuclear antibody levels were measured in 105 well-evaluated patients with refractory focal epilepsy. Clinical determinants included the patient history, electroclinical classification and high resolution brain magnetic resonance imaging. RESULTS: Patients with seizures during the month prior to sampling (recent seizures) had increased prevalence of immunoglobulin (Ig) G class anticardiolipin antibodies (29%) compared with healthy controls [13%; age-adjusted odds ratio (OR): 3.09, 95% confidence interval (CI): 1.30-7.34] and patients with no recent seizures (11%; age-adjusted OR: 4.00, CI: 0.84-19.02). The patients with recent seizures had increased prevalence of moderate positive IgG class anticardiolipin antibodies (12%) compared with the controls (4%) and the patients with no recent seizures (0%; age-adjusted OR: 4.45, CI: 1.14-17.36). The prevalence of IgG class anticardiolipin antibodies was not associated with epilepsy type, duration or aetiology. CONCLUSION: The presence of antiphospholipid antibodies is associated with recurrent seizures in patients with refractory focal epilepsy. The measurement of these antibodies may be useful in evaluating the outcome of epilepsy.

Predictive, protective, orphan autoantibodies: the example of anti-phospholipid antibodies.

Anti-phospholipid antibodies (aPL) are one of the most recent examples of autoantibodies that can appear even long time before any clinical manifestation can be associated with them. There is a general agreement that they may represent a strong risk factor for recurrent thrombosis and/or fetal losses. Anti-phospholipid antibodies represent a necessary but not sufficient factor (first hit) for thrombosis, and require additional triggering factors (second hit) to disclose the thrombogenic activity. Several factors may affect the predictive value of aPL, including titre, immunoglobulin isotype, fine antigenic specificity and affinity binding activity. Their careful evaluation is suggested in order to characterize the true predictive value of aPL.

Immunization of LDL receptor-deficient mice with beta2-glycoprotein 1 or human serum albumin induces a more inflammatory phenotype in atherosclerotic plaques.

Antiphospholipid antibodies are a risk factor for venous and arterial thrombosis and may contribute to the development of atherosclerosis.The aim of this study was to investigate whether antibodies to human beta2-glycoprotein 1 (beta2GP1), as a model of antiphospholipid antibodies, modify the phenotype of atherosclerotic lesions. LDL receptor-deficient mice were immunized with human beta2GP1, human serum albumin (HSA), or not immunized, and fed a high-cholesterol diet for 14 weeks. Some mice also received pravastatin. Immunization with human beta2GP1 or HSA resulted in formation of autoantibodies recognizing murine beta2GP1 or murine albumin, respectively. We quantified atherosclerotic lesion development and mRNA levels of inflammation associated proteins in the thoraco-abdominal aorta as well as lesion development,cellular composition and collagen content in the aortic roots. Immunization with beta2GP1 or HSA had no effect on lesion size,but modified the expression in plaque areas of several inflammation-associated proteins. Expression of matrix metalloproteinase-9, tissue factor, interferon-gamma and CD25 was highest in the thoraco-abdominal aorta of beta2GP1-immunized mice, lowest in non-immunized mice and intermediate in HSA-immunized animals. Immunization with beta2GP1, but not HSA, resulted in a lower smooth muscle cell and collagen content of lesions in aortic roots. Statin treatment partially reversed the effects of beta2GP1 immunization. We conclude that immunization with beta2GP1, and to a lesser extent with HSA, leads to modifications in the cellular and protein composition of atherosclerotic plaques, which are associated with a more inflammatory phenotype. Statin treatment partially prevents these changes.

The association of VP1 unique region protein in acute parvovirus B19 infection and anti-phospholipid antibody production.

BACKGROUND: Previous studies have postulated a connection between human parvovirus B19 (B19) infection and anti-phospholipid antibodies (aPL). Recently, the phospholipase domain of B19 has been linked to B19-VP1 unique region (VP1u). To elucidate the roles of VP1u in B19 infection and aPL production, the major reactivity of anti-B19-VP1u, anti-cardiolipin antibody (aCL), and anti-beta2-glycoprotein I (beta2GPI) antibody was evaluated. METHODS: Sera from 102 clinically suspected cases of B19 infection were analyzed by nested PCR and ELISA. Humoral responses of anti-B19-VP1u and anti-B19-VP1uD175A IgM/IgG antibodies, aCL and the anti-beta2GPI antibody were assessed by Western blot and ELISA. Absorption experiments were also performed to determine the binding specificity of immunoglobulins to B19-VP1u, CL and beta2GPI. RESULTS: Sera from patients with the diagnostic pattern DNA+/IgM+/IgG+ had a high frequency (57%) for recognition of CL and beta2GPI. Furthermore, adsorption experiments were performed by adding purified B19-VP1u, which partially suppressed the reactivity of anti-B19VP1u to CL and beta2GPI. CONCLUSIONS: Serum from patients with acute B19 infection has a high frequency in recognition of CL and beta2GPI, and the phospholipase domain observed in the B19-VP1u may have contributed to the production of aPL. These findings may provide a clue for understanding the roles of B19-VP1u in B19 infection and aPL production.

The Role of TLR4 on B Cell Activation and Anti-ß2GPI Antibody Production in the Antiphospholipid Syndrome.

High titer of anti-ß2-glycoprotein I antibodies (anti-ß2GPI Ab) plays a pathogenic role in antiphospholipid syndrome (APS). Numerous studies have focused on the pathological mechanism in APS; however, little attention is paid to the immune mechanism of production of anti-ß2GPI antibodies in APS. Our previous study demonstrated that Toll-like receptor 4 (TLR4) plays a vital role in the maturation of bone marrow-derived dendritic cells (BMDCs) from the mice immunized with human ß2-glycoprotein I (ß2GPI). TLR4 is required for the activation of B cells and the production of autoantibody in mice treated with ß2GPI. However, TLR4 provides a third signal for B cell activation and then promotes B cells better receiving signals from both B cell antigen receptor (BCR) and CD40, thus promoting B cell activation, surface molecules expression, anti-ß2GPI Ab production, and cytokines secretion and making B cell functioning like an antigen presenting cell (APC). At the same time, TLR4 also promotes B cells producing antibodies by upregulating the expression of B-cell activating factor (BAFF). In this paper, we aim to review the functions of TLR4 in B cell immune response and antibody production in autoimmune disease APS and try to find a new way for the prevention and treatment of APS.

Mitochondrial Dysfunction in the Liver and Antiphospholipid Antibody Production Precede Disease Onset and Respond to Rapamycin in Lupus-Prone Mice.

OBJECTIVE: Antiphospholipid antibodies (aPL) constitute a diagnostic criterion of systemic lupus erythematosus (SLE), and aPL have been functionally linked to liver disease in patients with SLE. Since the mechanistic target of rapamycin (mTOR) is a regulator of oxidative stress, a pathophysiologic process that contributes to the development of aPL, this study was undertaken in a mouse model of SLE to examine the involvement of liver mitochondria in lupus pathogenesis. METHODS: Mitochondria were isolated from lupus-prone MRL/lpr, C57BL/6.lpr, and MRL mice, age-matched autoimmunity-resistant C57BL/6 mice as negative controls, and transaldolase-deficient mice, a strain that exhibits oxidative stress in the liver. Electron transport chain (ETC) activity was assessed using measurements of oxygen consumption. ETC proteins, which are regulators of mitochondrial homeostasis, and the mTOR complexes mTORC1 and mTORC2 were examined by Western blotting. Anticardiolipin (aCL) and anti-ß2 -glycoprotein I (anti-ß2 GPI) autoantibodies were measured by enzyme-linked immunosorbent assay in mice treated with rapamycin or mice treated with a solvent control. RESULTS: Mitochondrial oxygen consumption was increased in the livers of 4-week-old, disease-free MRL/lpr mice relative to age-matched controls. Levels of the mitophagy initiator dynamin-related protein 1 (Drp1) were depleted while the activity of mTORC1 was increased in MRL/lpr mice. In turn, mTORC2 activity was decreased in MRL and MRL/lpr mice. In addition, levels of aCL and anti-ß2 GPI were elevated preceding the development of nephritis in 4-week-old MRL, C57BL/6.lpr, and MRL/lpr mice. Transaldolase-deficient mice showed increased oxygen consumption, depletion of Drp1, activation of mTORC1, and elevated expression of NADH:ubiquinone oxidoreductase core subunit S3 (NDUFS3), a pro-oxidant subunit of ETC complex I, as well as increased production of aCL and anti-ß2 GPI autoantibodies. Treatment with rapamycin selectively blocked mTORC1 activation, NDUFS3 expression, and aPL production both in transaldolase-deficient mice and in lupus-prone mice. CONCLUSION: In lupus-prone mice, mTORC1-dependent mitochondrial dysfunction contributes to the generation of aPL, suggesting that such mechanisms may represent a treatment target in patients with SLE.

Antibodies to glutamate receptor subtype 3 (GluR3) are found in some patients suffering from epilepsy as the main disease, but not in patients whose epilepsy accompanies antiphospholipid syndrome or Sneddon's syndrome.

Autoantibodies (Ab's) to the "B" peptide (amino acids 372-395) of glutamate/AMPA receptor subtype 3 (GluR3) are found in serum and cerebrospinal fluid of some patients with different types of epilepsy. Since such anti-GluR3B Ab's can activate and/or kill neurons in vitro and in vivo, they may contribute to epilepsy. To investigate whether anti-GluR3B Ab's may also be relevant to epilepsy when it accompanies some autoimmune-diseases, we tested for these Ab's in patients suffering from epilepsy that accompanies anti-phospholipid syndrome (APS) or Sneddon's syndrome (SNS), both being autoimmune-diseases with frequent neurological complications. We tested 77 pediatric patients whose epilepsy is their main disease; 31 adult patients whose epilepsy accompanies APS (primary or SLE-associated) or SNS; 45 epilepsy-free APS and SNS patients; and 90 healthy controls. Compared to the controls, significantly elevated anti-GluR3B Ab's were found in 22/77 (29%) patients whose epilepsy is their main disease, but in none of the patients whose seizures accompany APS or SNS. Yet, all the APS and SNS patients harbored the characteristic anti-phospholipid Ab's (aPL), directed against cardiolipin and beta2-glycoprotein I, and had lupus anti-coagulant. Thus, anti-GluR3B Ab's are not crossreactive with aPL, and not produced as a non-specific consequence of seizures on the one hand, or autoimmune-diseases on the other. Taken together with new findings accumulated recently in our lab, we suggest that anti-GluR3B Ab's are produced primarily in the periphery due to specific/non-specific "irritation" of the immune system, and that once they reach the brain via a leaky blood-brain barrier they may cause neuronal/glial damage and facilitate the outburst of epilepsy and additional neurological abnormalities. In contrast, the presence of anti-GluR3B Ab's does not seem to increase the probability of developing APS, SNS or the seizures that often accompany these autoimmune-diseases. These findings may have important diagnostic and therapeutic implications.

Neo-self antigens and the expansion of B-1 cells: lessons from atherosclerosis-prone mice.

The pathogenesis of atherosclerosis involves an inflammatory process that is modulated by the immune system, and within these complex responses we have discerned a possible role for an archetypic B-1 clone. We speculate that due to their immunogenicity and in vivo distribution the "neo"-self determinants created in oxidatively modified LDL are highly stimulatory for certain B-1 cell clones. These neo-self determinants, which can be created chemically, by somatic processes, may in fact represent the molecular analogues of somatic maturation, or even aging. These changes, including those on non-protein antigens induced by oxidative metabolism, amongst others, create neo-determinants against which the host no doubt can not develop rigorous B-cell tolerance. The onset of expression of these oxidative neo-determinants relatively late in development may well serve a useful function for the highly evolved mammalian immune system, as targeting by evolutionarily selected B-1 clones may facilitate the amplification of other useful antibody-mediated physiologic functions. As in the case of the T15 clone, these antibodies may aid in protection against common microbial pathogens. Hence we postulate that during the evolution of the adaptive immune system the neo-self antigenic milieu may have been exploited for the natural selection of primordial clonal specificities. The T15 B-1 clone may then illustrate a common paradigm in which there has been natural selection based on utility for the defense of the individual from environmental threats, as well as for possible "housekeeping" role(s) and the maintenance of cellular homeostasis.

Autoimmunity and anti-TNF-alpha agents.

Treatment of rheumatoid arthritis (RA) patients with anti-tumor necrosis factor-alpha (anti-TNF-alpha) biologic agents has been associated with a reduction in the levels of specific autoantibodies, such as rheumatoid factor (RF) and anticyclic citrullinated peptide (anti-CCP), and the induction of non- organ-specific autoantibodies (antinuclear antibodies [ANAs], anti-dsDNA, and antiphospholipid antibodies [aPLs]). The mechanisms by which the blockade of anti-TNF-alpha decreases the generation of specific autoantibodies, such as anti-CCP and RF, are not yet known. However, it has been shown that these agents can downregulate the production of several inflammatory cytokines and mediators and that these anti-inflammatory effects may account for reduced autoantibody generation, particularly in the synovial compartment. Infliximab treatment leads to the induction of ANAs in 63.8% of RA patients and 49.1% of Crohn's disease (CD) patients, and anti-dsDNA antibodies in 13% of RA patients and 21.5% of CD patients, respectively. The development of ANAs and anti-dsDNA antibodies has also been described after etanercept therapy in 11% and 15% of RA patients, respectively. In the controlled trials, increases in ANA and anti-dsDNA titers were observed in 5.3% and in 12.9% of adalimumab-treated RA patients. Only limited data on the induction of aPL antibodies during TNF-alpha blocking treatment are available.

The prevalence of a non-phospholipid-binding form of beta2-glycoprotein I in human plasma--consequences for the development of anti-beta2-glycoprotein I antibodies.

The presence of antiphospholipid antibodies (aPL) is strongly correlated with venous and arterial thrombosis, fetal loss and thrombocytopenia. This relation is called the antiphospholipid syndrome (APS). It is well recognized that thrombosis related aPL are not directed against phospholipids alone, but to phospholipid bound plasma proteins like beta2-glycoprotein I (beta2GPI). aPL that need beta2GPI for the binding to negatively charged phospholipids are called anti-beta2GPI-antibodies. Recently, a mutation in the gene encoding beta2GPI has been described, which results in an amino acid substitution Trp316 into Ser316. This Ser316-beta2GPI did not bind to negatively charged phospholipids. Because only phospholipid bound beta2GPI is recognized by human anti-beta2GPI-antibodies, it might be argued that individuals carrying the Trp316Ser mutation are protected against the development of anti-beta2GPI-antibodies. To investigate this hypothesis, the prevalence of the Trp316Ser mutation was measured in 170 systemic lupus erythematosus (SLE) patients and in 18 patients with the primary antiphospholipid syndrome (PAPS) and the mutation was correlated with the presence of anti-beta2GPI-antibodies. In the total patient group 1 homozygous patient and 21 heterozygous patients were found. The allele frequency of the mutation in SLE patients with anti-beta2GPI-antibodies (0.063) was comparable to that found in SLE patients without anti-beta2GPI-antibodies (0.062). These results indicate that the heterozygous presence of Trp316Ser mutation does not prevent an individual from developing anti-beta2GPI-antibodies. We showed that this can be explained by the concentration of Trp316-beta2GPI in heterozygous patients, which is far above the minimal beta2GPI level necessary for optimal phospholipid binding. In our single patient homozygous for the Trp316Ser mutation no binding beta2GPI to the phospholipid surface was detected and no anti-beta2GPI-antibodies were present in the plasma of this patient. In conclusion, heterozygous Trp316Ser beta2GPI persons are not protected against the development of anti-beta2GPI-antibodies. To confirm that homozygotes do not develop anti-beta2GPI-antibodies a very large population is needed, due to the relatively low prevalence of the mutation.

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.

Intravenous immunoglobulin infusion therapy in women with recurrent spontaneous abortions of immune etiologies.

We have investigated clinical effectiveness of intravenous immunoglobulin G infusion (IVIg) on antiphospholipid antibody titers in five women with evidence of antiphospholipid antibody-associated recurrent spontaneous abortions and one with antinuclear antibody who became refractory to conventional autoimmune treatment during pregnancy and experienced pregnancy complications. Three women developed intrauterine growth retardation and three had complicated twin pregnancies with rising autoantibody titers. Antiphospholipid antibody and antinuclear antibody titers were tested pre and 2 weeks after each IVIg infusion. We report that: (i) IgG antiphospholipid antibody titers were significantly suppressed after each IVIg infusion (P < 0.05); (ii) IgM antiphospholipid antibody titers were also significantly suppressed after each IVIg infusion (P < 0.0001); (iii) decreased titers of autoantibodies paralleled increased levels of maternal IgG which lasted for at least 30 days; the autoantibodies showed a definite rise again prior to the next infusion; (iv) antinuclear antibody titers were effectively suppressed; and (v) rising autoantibody titers combined clinical manifestation of intrauterine growth retardation and women with complicated twin pregnancies. We conclude that IVIg infusion effectively suppresses IgM and IgG autoantibodies to phospholipids and antinuclear antibody in autoimmune women with a history of recurrent spontaneous abortions and refractory to conventional anticoagulation or immunosuppressive treatment.

HIV infection and antiphospholipid antibody: literature review and link to the antiphospholipid syndrome.

There is a high incidence of antiphospholipid antibodies, detected by assays for anticardiolipin or lupus-like anticoagulant, in HIV disease. However, a link to the antiphospholipid syndrome, with clinical thrombosis, is tenuous. We report a case of a 25-year-old man with undetermined risk factors for HIV presenting with possible antiphospholipid syndrome manifesting as necrotic skin lesions as the initial clinical presentation for HIV. We also review the literature exploring the association between HIV and antiphospholipid syndrome.

Recurrent abortion and moderate or strong antiphospholipid antibody production.

OBJECTIVE: To investigate the treatment outcome for women suffering recurrent miscarriages associated with strong or moderate antiphospholipid antibody (aPL) production. METHODS: Sixty-seven pregnancies in 61 women demonstrating at least one kind of aPL with a history of recurrent miscarriages were treated with: (1) aspirin (ASA) alone; (2) prednisolone (PSL) and ASA; and (3) PSL, ASA, heparin and/or immunoglobulin (IgG). For comparison purposes the aPL-positive patients were divided into two groups, strongly and moderately-positive. IgG and IgM antibodies against PE and five negatively-charged phospholipids were measured by ELISA between 1987 and 1993. Beta2-glycoprotein I (beta2GPI) dependent anticardiolipin antibodies were measured by ELISA since 1993. Lupus anticoagulant was measured by a diluted aPTT method since 1993. RESULTS: Out of a total of 16 (50%) patients strongly-positive for aPL and 47 out of 51 (92.2%) moderately-positive demonstrated a successful outcome. The live birth rate moderate group was significantly higher than in the strongly-positive cases (P < 0.0005). In the cases exhibiting moderate aPL production, 28 out of 30 (93.3%) receiving PSL and ASA and 14 out of 15 (93.3%) treated with ASA alone successfully gave birth. None of the 14 given ASA alone suffered preterm delivery or IUGR. In contrast 12 (36.4%) and 6 (18.2%) of the 33 patients treated with the PSL combination therapy suffered from preterm delivery and IUGR, respectively. CONCLUSIONS: The live birth rate in patients strongly positive for aPL is lower than that in patients with moderate aPL production even if treatment is performed during pregnancy. However, ASA is useful to treat cases with moderate aPL so that distinction of the two groups is warranted.

Antiphospholipid antibodies mediate autoimmunity against dying cells.

The Antiphospholipid Syndrome (APS) is characterized by thrombosis and pregnancy loss, clinical events mediated by pathogenic anti-phospholipid autoantibodies (aPL). ß2-glycoprotein I (ß2GPI) is the major autoantigens recognized by aPL. ß2GPI is a cationic protein that binds to negatively charged surfaces such as those of apoptotic cells. This feature may lead to two major events: i) immunization with ß2GPI fosters the Fc-receptor-mediated uptake by antigen presenting cells of apoptotic material decorated with ß2GPI and the activation of ß2GPI-specific T cells which in turn provide help to ß2GPI-specific B cells for the production of anti-ß2GPI; ii) apoptotic bodies decorated with ß2GPI can be opsonized by anti-ß2GPI and shifted towards a pro-inflammatory clearance by macrophages; epitope spread can occur with the generation of autoimmunity against nuclear autoantigens. In the presence of a predisposing genetic background and of a particular cytokine environment (type I interferons), the sequential emergence of autoantibodies can evolve into overt clinical disease. The spectrum of clinical phenotypes of the patients can be modulated by several factors affecting the pathogenicity of anti-ß2GPI (e.g. domain specificity). We conclude that dying cells may play a dual role in APS: (I) as immunogen for the induction of aPL (etiology) and (II) as targets of aPL for the chronification of inflammation and the development of autoimmune diseases (pathology).