The antiphospholipid (Hughes') syndrome: an entity to be expanded

Antiphospholipid syndrome (APS): where does it come from?

The antiphospholipid syndrome (APS) is the most common acquired thrombophilia. It is characterized by venous and arterial thrombosis, recurrent pregnancy loss, and various other clinical manifestations in the presence of antiphospholipid antibodies (aPL). Like other autoimmune diseases, the etiology of APS derives from a combination of genetic and environmental factors. The most significant environmental factors in APS are infectious agents, followed by trauma and drugs. Infections can induce aPL and, in the catastrophic variant of APS, about one-third of cases are associated with a clear recent infection. On their formation, aPL have been clearly shown to be pathogenic, because they influence all arms of the coagulation system and because passive transfer and active immunization protocols have demonstrated. Therefore, in a genetically susceptible individual, exposure to one or more infectious agent can cause a molecular mimicry and result in the production of pathogenic aPL that can induce thrombosis and pregnancy loss. Identification of the epitopes within the beta-2-glycoprotein-I molecule that serves as the target for autoantibodies makes them the target for immunomodulation of the syndrome.

Autoantibody explosion in antiphospholipid syndrome

Antiphospholipid syndrome (APS) is characterized by thrombosis and pregnancy loss in the presence of antiphospholipid antibodies (aPL), mainly anticardiolipin, anti-beta2-glycoprotein I and lupus anticoagulant. However, similar to systemic lupus erythematosus, APS is also characterized by multiple other autoantibodies including 'non-classical' aPL, as well as other antibodies. Herein we describe the autoantigen properties, prevalence and clinical importance of 30 different antibodies in APS. Among the other antibodies characterizing APS are autoantibodies directed to platelets, glycoproteins, various coagulation factors, lamins, mitochondrial antigens and cell surface markers. Few of these autoantibodies are correlated with the presence of other antibodies, and some may have an additive role in the pro-thrombotic tendency of the syndrome. This autoantibody explosion might be important in early identification of the syndrome and its manifestations.

Prevalence of Antiphospholipid and Antioxidized Low-Density Lipoprotein Antibodies in Rheumatoid Arthritis

Antiphospholipid antibodies characterize the antiphospholipid syndrome (APS), but they can also be found in various autoimmune, infectious, and malignant conditions. This study's objectives were to detect the prevalence of antiphospholipid and antioxidized low-density lipoprotein (anti-oxLDL) antibodies among patients with rheumatoid arthritis (RA) who did not have clinical manifestations of APS. Using a standard enzyme-linked immunosorbent assay (ELISA), we evaluated the levels of immunoglobulin G (IgG) and IgM anticardiolipin, IgG, and IgM anti-beta-2-glycoprotein-I (anti-beta(2)GPI), and anti-oxLDL autoantibodies in 82 patients with RA. The cutoff levels for detecting these autoantibodies were 15 IgG phospholipid units (GPL), 15 IgM phospholipid units (MPL), and 25 ELISA units (EU)/mL, respectively. Elevated levels of IgG anticardiolipin antibodies were detected in 17 of 82 (21%) RA patients, including 10 with low levels of IgG anticardiolipin and 7 with medium to high levels of anticardiolipin autoantibodies. IgM anticardiolipin was found in only 1 (1%) patient, and both IgG and IgM anti-beta(2)GPI were found in 3 (4%) patients with RA. Elevated levels of anti-oxLDL antibodies were found in 8 (10%) patients, 4 of whom also had elevated levels of IgG anticardiolipin. We conclude that IgG anticardiolipin autoantibodies can be found in about one-fifth of RA patients who do not have clinical manifestations of APS. Whether the presence of anticardiolipin signifies increased risk for thrombosis and atherosclerosis in these patients should be studied further.

The immunological "Wars of the Roses": disagreements amongst reproductive immunologists

The relevance of abnormal autoimmune function to reproductive function in the female has over recent years become an increasingly controversial and contentious issue. Opposing views have led to a polarization of opinions which, at times, resulted in publications of rather vocal opinions by individuals as well as societal committees. This communication is an attempt to reconcile these, at times diametrically opposing opinions, in a concept of (auto)immune-driven reproduction failure, which could explain and unify these opposing opinions and, thus, hopefully end the ongoing "immunological wars of the roses".

Antiphospholipid antibody levels in intravenous immunoglobulin (IVIg) preparations

The antiphospholipid syndrome (APS) is characterized by various clinical manifestations and by elevated levels of antiphospholipid antibodies. Passive induction of APS by infusion of these antibodies has been demonstrated in animal models. Intravenous immunoglobulin (IVIg) is one of the therapeutic options in APS. In this study, five commercially used preparations of IVIg were tested for the presence of elevated levels of cardiolipin, beta-glycoprotein-I, phosphatidylserine, antinuclear, and double-stranded DNA autoantibodies, as well as for lupus anticoagulant activity. The absence of abnormal elevated levels of any of these autoantibodies in five different IVIg preparations provides additional evidence for the safety of IVIg use in APS.

Induction and treatment of the antiphospholipid syndrome--lessons from animal models

The diagnosis of antiphospholipid syndrome (APS) is based on a combination of clinical and serological criteria. This review summarizes the literature regarding animal models of APS. Animal models of this syndrome help to elucidate pathogenic roles of the characteristic antiphospholipid antibodies in pregnancy morbidity, vascular thrombosis, neurologic disease and atherosclerosis. Furthermore, these models also provide measures to evaluate novel therapies for APS. These include bone-marrow transplantation, intravenous immunoglobulin, anticoagulation, interleukin-3, in addition to other therapies. Experimental induction and treatment of APS largely contributes to our understanding of the disease and to better management of its clinical characteristics.

Coronary calcium and anti-cardiolipin antibody are elevated in patients with typical chest pain

The aim of this study was to examine whether detection of coronary calcium and the autoimmune response associated with atherosclerosis, either solely or in combination, are different in patients with typical and atypical chest pain. Coronary calcium as detected by spiral computerized tomography and levels of antibodies against cardiolipin (CL), oxidized low-density lipoprotein (ox-LDL), and beta2-glycoprotein-I (beta2-GPI) were studied in patients with typical chest pain (n = 52), atypical chest pain (n = 19), or without chest pain (n = 21). Patients with typical chest pain had higher mean levels of coronary calcium (expressed as natural transformation of total coronary calcium score) compared with patients with atypical chest pain and controls (5.04 vs 3.21 and 2.75, respectively; p < 0.001). The levels of anti-CL were (mean +/- SD of optical density multiplied by 1,000): 262 +/- 140, 170 +/- 82, and 230 +/- 115 for patients with typical chest pain, atypical chest pain, and controls, respectively (p = 0.016). No significant difference was found between groups regarding anti-ox-LDL and anti-beta2-GPI autoantibody levels. In the typical chest pain group, there was a higher prevalence of high total coronary calcium scores (p = 0.03) and high anti-CL levels (p = 0.01) than in the atypical chest pain group. Eighteen of 52 patients with typical chest pain (35%) had both high calcium scores and high antibody levels, whereas none of the 19 patients (0%) who had atypical chest pain had high levels of both (p = 0.003). A combination of both coronary calcium and anti-CL was associated with higher area under the receiver operator characteristic curves than for each separately. High coronary calcium scores or high anti-CL levels are found more often in typical than in atypical chest pain patients, but a combination of high levels of both can better differentiate typical from atypical chest pain patients.

Antiphospholipid syndrome: insights from animal models

Animal models of the relatively new antiphospholipid syndrome (APS) enabled researchers to understand disease pathogenesis and to test novel experimental therapeutic modalities. Animal models of APS include spontaneous genetic models and experimental induced models. The latter test more reliably the pathogenicity of antiphospholipid antibodies because the syndrome is induced in normal mice rather than being secondary to a preexisting autoimmune disease. Reports about animal models of APS in the recent year provide new insights into the pathogenesis of antiphospholipid antibodies and beta2-glycoprotein-I in reproductive failure, neurologic manifestations, thrombosis, and atherosclerosis. In addition, novel therapies that were successful in experimental APS included anti-idiotypes, oral tolerance, and specific peptides that bind to beta2-glycoprotein-I. Animal models provide the first step in development of novel therapies for patients with APS.

Dermatomyositis and polymyositis associated with the antiphospholipid syndrome-a novel overlap syndrome

OBJECTIVE

As APS (antiphospholipid syndrome) can be either primary or secondary to a wide range of other conditions (such as autoimmune diseases, malignancies, infectious diseases, and drug-induced conditions) the aim of this study was to describe a novel overlap syndrome of APS.

METHODS

All patients diagnosed with either PM (polymytosis) or DM (dermatomytosis) who were treated in the Rheumatology Unit, Sheba Medical Center, were followed-up in the past 8 years for the appearance of a clinical manifestation of the APS, and conversely, patients with APS treated by us were clinically assessed for the presence of signs and symptoms of PM and DM. Both conditions were diagnosed according to accepted diagnostic criteria.

RESULTS

Three patients were found to have both APS and PM/DM. A patient with PM had transverse myelopathy, a patient with DM had pulmonary embolism, and a patient with PM had recurrent abortions, stroke, livedo reticularis and mitral regurgitation. Both patients with PM had also SLE (systemic lupus erythematosis).

CONCLUSIONS

APS can be associated with a wide range of diseases. Future data would reveal which therapy is the best for the association of PM/DM with APS, and determine the pathogenesis and prognosis in patients with this association.