Factors at diagnosis predict subsequent occurrence of seizures in systemic lupus erythematosus

Objective: To determine the factors associated with seizures in systemic lupus erythematosus (SLE).

Methods: One hundred ninety-five patients with SLE were followed at the University of Maryland Lupus Clinics from January 1992 until June 2004. Neuropsychiatric (NP) manifestations were defined according to the American College of Rheumatology nomenclature and case definitions for NP-SLE syndromes, and seizures were defined using the International Classification of Epileptic Seizures. At the end of the study period, 28 of the 195 (14%) patients with SLE had seizures (21 generalized convulsive, 7 partial) during their course of disease. Recurrent seizures or epilepsy occurred in 12 of 28 patients (43%). The baseline features of those patients with seizures and those without them were compared to determine their contribution to the occurrence of isolated seizures and epilepsy.

Results: Isolated seizures in SLE are common; epilepsy is less frequent but nonetheless important. Certain clinical features at baseline were independent predictors of seizures including disease activity, in particular psychosis, moderate- to high-titer serum anti-cardiolipin and anti-Smith antibodies, and damage accrual. Higher disease activity at baseline, concurrent multiple NP-SLE manifestations, prior strokes, and male gender were predictive of epilepsy.

Conclusion: The risk of seizure and epilepsy in systemic lupus erythematosus (SLE) is increased in those patients with higher disease activity at baseline, prior neuropsychiatric SLE disease, and anti-cardiolipin and anti-Smith antibodies.

Cardiolipin polyspecific autoreactivity in two broadly neutralizing HIV-1 antibodies

The design of a human immunodeficiency virus-1 (HIV-1) immunogen that can induce broadly reactive neutralizing antibodies is a major goal of HIV-1 vaccine development. Although rare human monoclonal antibodies (mAbs) exist that broadly neutralize HIV-1, HIV-1 envelope immunogens do not induce these antibody specificities. Here we demonstrate that the two most broadly reactive HIV-1 envelope gp41 human mAbs, 2F5 and 4E10, are polyspecific autoantibodies reactive with the phospholipid cardiolipin. Thus, current HIV-1 vaccines may not induce these types of antibodies because of autoantigen mimicry of the conserved membrane-proximal epitopes of the virus. These results may have important implications for generating effective neutralizing antibody responses by using HIV-1 vaccines.

Pregnancy, patent foramen ovale and stroke: a case of pseudoperipheral facial palsy

The pathogenetic role of patent foramen ovale (PFO) in embolic stroke and its prognostic and therapeutic implications have not yet been clearly defined. Nonetheless, recent availability of non-invasive diagnostic techniques, such as the transcranial Doppler (TCD), has increased the frequency with which this anomaly is diagnosed. Here we present the case of a young woman affected by post-partum peripheral facial palsy: further exams disclosed not only its truncal-ischaemic origin, but also, significantly, the presence of PFO, as well as of anticardiolipin antibodies (acL). Given the increased embolic risk in labouring women, this study highlights the importance of searching for PFO in case of a stroke during pregnancy.

Acquired Activated Protein C Resistance Associated with IgG Antibodies against β2-Glycoprotein I and Prothrombin as a Strong Risk Factor for Venous Thromboembolism

Background: Venous thromboembolic events such as deep vein thrombosis and pulmonary embolism are common manifestations of antiphospholipid syndrome. Our aim was to clarify the roles of anti-phospholipid (aPL) antibodies in the pathogenesis of venous thromboembolism (VTE) in patients with systemic lupus erythematosus (SLE).

Methods and Results: We examined anti-cardiolipin/β2-glycoprotein I (anti-CL/β2-GPI) antibody concentrations, anti-phosphatidylserine/prothrombin (anti-PS/PT) antibody concentrations, and lupus anticoagulant (LA) activity in 87 patients with SLE (21 with VTE and 66 without thrombosis). Both anti-CL/β2-GPI and anti-PS/PT antibodies strongly correlated with LA activity. Multivariate logistic analysis confirmed that both anti-CL/β2-GPI and anti-PS/PT antibodies were significant independent risk factors for VTE (odds ratios = 4.98 and 7.54, respectively; 95% confidence intervals, 1.51–16.4 and 2.30–24.7, respectively). We therefore studied the in vitro effects of IgG fractions containing anti-CL/β2-GPI or anti-PS/PT antibodies on the anticoagulant activity of activated protein C (APC) and found that purified IgG containing anti-CL/β2-GPI or anti-PS/PT antibodies significantly hampered the anticoagulant activity of APC. We also studied the ability of IgG fractions to impede the anticoagulant activity of APC before and after complete removal of anti-CL/β2-GPI or anti-PS/PT antibodies by adsorption. Removal of anti-CL/β2-GPI or anti-PS/PT antibodies from all positive IgG samples clearly decreased the inhibitory effect of those samples on APC anticoagulant activity.

Conclusions: Anti-CL/β2-GPI and anti-PS/PT antibodies independently cause APC resistance, which may contribute to risk of VTE in patients with SLE.

Lack of association between anti-phospholipid antibodies (APLA) and Attention Deficit/Hyperactivity Disorder (ADHD) in children

Numerous studies have shown the pathological influence anti-phospholipid antibodies (APLA) have on the physiology of the single neuron as well as the function of the entire human nervous system. The influence is well demonstrated in the antiphospholipid syndrome (APS). This syndrome is characterized by a triad of arterial or venous thrombotic events, recurrent fetal loss and thrombocytopenic purpura. The syndrome exhibits different neurological pathologies such as: chorea, seizures, transverse myelopathy, migraine, cerebral ataxia, hemiballismus and transient global amnesia, which are not fully explained by the procoagulopathic trait of APLA. A study on mice induced with APS demonstrated hyperactive behavior when compared to the control group. The information gathered from these different studies raised the question whether APLA has any part in the etiology of Attention Deficit/Hyperactive Disorder (ADHD) in children.

We compared 41 children diagnosed with ADHD to a control of 28 healthy children. Blood drawn from the two groups was screened using ELISA for the presence of anti-cardiolipin antibodies, antiβ2GP antibodies, anti-phosphatidyleserine antibodies and anti-ethanolamine antibodies. The results show no significant difference in the level of antiphospholipid antibodies (APLA) measured between the children diagnosed with ADHD and the control group.

IgG autoantibodies against beta2-glycoprotein I complexed with a lipid ligand derived from oxidized low-density lipoprotein are associated with arterial thrombosis in antiphospholipid syndrome

We recently reported [J. Lipid Res. 42 (2001), 697; 43 (2002), 1486; 44 (2003), 716] that β₂-glycoprotein I (β₂GPI) forms complexes with oxidized LDL (oxLDL) and autoantibodies against these complexes are present in patients with SLE and antiphospholipid syndrome (APS). The relationship of β₂GPI/oxLDL complexes and IgG autoantibodies against β₂GPI complexed with oxLig-1 (an oxLDL-derived ligand) with clinical manifestations of APS was studied in 150 APS and SLE patients. The β₂GPI/oxLDL levels of APS patients were similar to those of SLE patients without APS, but they were significantly higher than healthy individuals. There was no difference in the complex levels among the patients with arterial, venous thrombosis, or pregnancy morbidity. IgG anti-β₂GPI/oxLig-1 levels of APS were significantly higher than those of SLE without APS and healthy individuals. Further, antibody levels of APS patients with arterial thrombosis were significantly higher than those patients with venous thrombosis and pregnancy morbidity. Thus, oxidation of LDL leads the complex formation with β₂GPI in SLE and APS patients. In contrast, anti-β₂GPI/oxLig-1 autoantibodies were generated only in APS and were strongly associated with arterial thrombosis. These results suggest that autoantibodies against β₂GPI/oxLDL complexes are etiologically important in the development of atherosclerosis in APS.

[Effects of Eupolyphaga Sinensis Walker on erythrocyte's CR1 activity and anti-cardiolipin antibody level in rats with stagnation of blood]

AIM

To study the effect of Eupolyphaga Sinensis Walker(ESW) on red blood cell immune adherence (RCIA) and serum anticardiolipin antibody level in rat model of Yin-deficiency Huo-excess with chronic blood stasis.

METHODS

The model was made by i.m. injection of dexamethasone (0.5 mg/kg) and adrenaline (0.84 mg/kg). The serum anti-cardiolipin antibodies (ACA) ACA-IgG, ACA-IgA and ACA-IgM and the plasma D-dimmer levels were measured by using enzyme-linked immunosorbent assay (ELISA). The body and organ weight of the rats were measured.

RESULTS

For rats of Yin-deficiency Huo-excess, rosette rates of red blood cell C3b receptors (RBC-C3b RR) and red blood cell cancer (RBC-CaR) decreased, the serum ACA-IgG, ACA-IgA, ACA-IgM and the plasma D-dimmer levels markedly increased, body weight and the weight of spleen and thymus all decreased. ESW (5 mg/kg, 10 mg/kg) increased RBC-C3bRR and RBC-CaR, reduced serum ACA-IgG, ACA-IgA, ACA-IgM and plasma D-dimmer levels, and increased spleen weight of the rats.

CONCLUSION

ESW can boost the immune function in rats of Yin-deficiency Huo-excess with chronic blood stasis.

Thrombosis and the Antiphospholipid Syndrome

The antiphospholipid syndrome is an antibody-mediated hypercoagulable state characterized by recurrent venous and arterial thromboembolic events. Several studies have determined that the frequency of antiphospholipid syndrome in patients presenting with a venous thromboembolic event is between 4% and 14%. Because of the high risk for recurrent thromboembolism in these patients, current recommendations suggest a longer, potentially lifelong, course of antithrombotic therapy following an initial event. Although most authorities agree on an extended course of therapy, considerable controversy surrounds the optimal target therapeutic INR for patients with antiphospholipid syndrome. For an initial venous thromboembolic event, a target INR of 2.0 to 3.0 is supported by two prospective, randomized clinical trials. In contrast, relatively limited data exist for an initial arterial thromboembolic event in patients who have the antiphospholipid syndrome, and therapeutic recommendations range from aspirin to warfarin with a high target INR. Recurrent thromboembolic events can be extremely difficult to treat, and some patients may benefit from the addition of immunosuppressive therapies. Importantly, as many as 50% of the initial thromboembolic events sustained by patients with antiphospholipid antibodies occur in the setting of additional, coincident prothrombotic risk factors, indicating the importance of addressing any additional risk factors, such as hypercholesterolemia, in these patients. Prospective studies are needed to address the role of thromboprophylactic strategies in asymptomatic individuals with antiphospholipid antibodies in the absence of additional risk factors.

[Analysis of specificity of antiphospholipid antibodies with the use of monoclonal antibodies to phospholipids]

The antigenic specificity of antiphospholipid antibodies (APA) is a matter of intensive investigation. Difference in the reported involvement of APA in clinical manifestation may be due, in part, to the polyclonal nature of these antibodies and the use of serum and serum fractions for analysis. To circumvent this issue, we generated mouse monoclonal APA and compared their antigen binding patterns and conditions of this reaction. Monoclonal APA 5A1 and 1B10 reacted with cardiolipin in a beta2-glycoprotein 1-dependent manner. The epitope for these antibodies consisted of beta2-glycoprotein 1 bound to cardiolipin or immobilized on plastic plates. The specificity is similar to the autoimmune anticardiolipin antibodies described in patients with SLE, APS and other autoimmune diseases. Monoclonal APA 510, 183, 238 reacted with cardiolipin in the absence of beta2-glicoprotein 1. beta2-Glicoprotein 1 , either in the fluid phase or bound to cardiolipin, inhibited the binding of these antibodies. Monoclonal APA 510 was cofactor-independent while monoclonal APA 183 and 238 reacted with cardiolipin only in the presence of human serum. The results of this study indicate that APA comprise a highly heterogeneous population of antibodies with respect to the antigens they recognize, as well as depending on presence of serum components.

Decreased Binding of Annexin V to Endothelial Cells

Objective— The cause of the exceedingly high risk of atherothrombosis in systemic lupus erythematosus (SLE) is not clear but antiphospholipid antibodies (aPL) and potentially antithrombotic annexin V have been implicated.

Methods and Results— Twenty-six women (52±8.2 years) with SLE and a history of cardiovascular disease (CVD) (SLE cases) were compared with 26 women with SLE but no CVD (SLE controls) and 26 healthy women (population controls). Common carotid intima-media thickness (IMT) was determined by B-mode ultrasound as a surrogate measure of atherosclerosis. Annexin V binding to human umbilical vein endothelial cells (HUVECs) as determined by flow cytometry after 24-hour culture with plasma was decreased when plasma from SLE cases was used (SLE cases versus population controls: P =0.002; SLE cases versus SLE controls P =0.02). Antibodies against cardiolipin were among IgG antibodies causing decreased binding. There was a positive association between annexin V binding and IMT ( R =0.73; P <0.001) among SLE cases. Immunohistochemical analysis revealed presence of annexin V in all human atherosclerotic plaques tested, especially at sites prone to rupture.

Conclusions— Decreased annexin V binding to endothelium caused by antibodies may represent a novel mechanism of atherothrombosis. We hypothesize that even though annexin V may promote plaque growth at some disease stages, it may also stabilize plaque.

The critical role of arginine residues in the binding of human monoclonal antibodies to cardiolipin

Previously we reported that the variable heavy chain region (V_H) of a human beta₂ glycoprotein I-dependent monoclonal antiphospholipid antibody (IS4) was dominant in conferring the ability to bind cardiolipin (CL). In contrast, the identity of the paired variable light chain region (V_L) determined the strength of CL binding. In the present study, we examine the importance of specific arginine residues in IS4V_H and paired V_L in CL binding. The distribution of arginine residues in complementarity determining regions (CDRs) of V_H and V_L sequences was altered by site-directed mutagenesis or by CDR exchange. Ten different 2a2 germline gene-derived V_L sequences were expressed with IS4V_H and the V_H of an anti-dsDNA antibody, B3. Six variants of IS4V_H, containing different patterns of arginine residues in CDR3, were paired with B3V_L and IS4V_L. The ability of the 32 expressed heavy chain/light chain combinations to bind CL was determined by ELISA. Of four arginine residues in IS4V_H CDR3 substituted to serines, two residues at positions 100 and 100 g had a major influence on the strength of CL binding while the two residues at positions 96 and 97 had no effect. In CDR exchange studies, V_L containing B3V_L CDR1 were associated with elevated CL binding, which was reduced significantly by substitution of a CDR1 arginine residue at position 27a with serine. In contrast, arginine residues in V_L CDR2 or V_L CDR3 did not enhance CL binding, and in one case may have contributed to inhibition of this binding. Subsets of arginine residues at specific locations in the CDRs of heavy chains and light chains of pathogenic antiphospholipid antibodies are important in determining their ability to bind CL.

Safety and efficacy of tumor necrosis factor ? blockade in systemic lupus erythematosus: An open-label study

OBJECTIVE

To investigate the safety of therapeutic tumor necrosis factor alpha (TNFalpha) blockade in patients with systemic lupus erythematosus (SLE), in whom this proinflammatory cytokine is significantly increased and may be involved in the disease pathogenesis.

METHODS

In an open-label study, 6 patients with moderately active SLE (4 with nephritis and 3 with arthritis refractory to other therapies) were given 4 300-mg doses of infliximab, a chimeric anti-TNFalpha antibody, in addition to immunosuppression with azathioprine or methotrexate.

RESULTS

The only significant adverse events observed were urinary tract infection in 3 patients, 1 of which was accompanied by Escherichia coli bacteremia, and a prolonged febrile episode of putatively viral origin in 1 of them. These patients had similar infectious conditions in the past. In none of the patients was it necessary to terminate the treatment prematurely. Levels of antibodies to double-stranded DNA and cardiolipin increased in 4 patients each, but this was not associated with a decrease in serum complement levels, with vascular events, or with flares. In contrast, disease activity declined during therapy. All 3 patients with joint involvement experienced remission of arthritis, which relapsed 8-11 weeks after the last infliximab infusion. In the 4 patients with lupus nephritis, proteinuria decreased significantly within 1 week after initiation of therapy and was diminished by > or = 60% within 8 weeks, remaining at low levels until the end of the observation period (at least several months).

CONCLUSION

Infliximab did not lead to adverse events related to an increase in SLE activity, although autoantibodies to double-stranded DNA and cardiolipin increased, as expected. This finding, coupled with the clinical improvement in the inflammatory manifestations of the disease, indicates that further study in larger controlled trials is warranted.

Anti-beta 2 glycoprotein I antibodies in centenarians

BACKGROUND

Non-organ-specific autoantibodies are present in centenarians without evidence of autoimmune diseases but conflicting or no data on anti-phospholipid and anti-phospholipid binding proteins were reported.

OBJECTIVE

To investigate the presence and antigen specificity of anti-phospholipid and anti-phospholipid binding proteins in centenarians.

METHODS

Seventy-seven centenarians, 70 adult controls, 65 unselected elderly subjects, and 38 old SENIEUR volunteers were investigated. Anti-cardiolipin, anti-human beta 2 glycoprotein I, and lupus anticoagulant were detected. Antigen specificity was assayed against plates coated with anionic, neutral and cationic phospholipids and beta 2 glycoprotein I-dependence was also evaluated.

RESULTS

54.3% of the centenarians were positive for IgG and 8.6% for IgM anti-beta 2 glycoprotein I antibodies, while only 20.7% centenarians were positive for anti-cardiolipin IgG and 2.59% for IgM; none resulted positive for lupus anticoagulant. Anti-cardiolipin positive sera cross-reacted with negatively charged phospholipids and displayed decreased binding to serum-free cardiolipin-coated plates that was restored by human beta 2 glycoprotein I or fetal calf serum.

CONCLUSIONS

Centenarians display high reactivity against human beta 2 glycoprotein I but low binding to the bovine molecule in the anti-cardiolipin assay. In spite of the presence of antibodies comparable to those found in patients with the anti-phospholipid syndrome, no vascular events were reported suggesting the presence of unknown protective factors and/or the lack of triggering factors.

Assessing the variation in antiphospholipid antibody (APA) assays: comparison of results from 10 centers

OBJECTIVE

This study was undertaken to determine the variability of antiphospholipid antibody (APA) assay results of cardiolipin and other frequently tested phospholipids. Study design Ten centers performing APA assays submitted samples that were positive in their assay. Twenty samples were identified to cover a broad range of APA results. Samples were distributed to the 10 participating centers for evaluation of immunoglobulin G (IgG), IgM, and IgA antibodies to phospholipids.

RESULTS

Of 20 patients, 9 (45%) were identified as positive by all 10 centers and 2 of 20 patients (10%) were identified as positive by 8 or 9 centers. However, 9 of 20 samples (45%) returned with mixed results. The average percent of positive samples was 29%, but results from the 10 centers ranged from a low number of positives (13%) to a high number of (37%).

CONCLUSION

When considering a clinical diagnosis of APA syndrome, laboratory concordance of results from 20 patient samples among the 10 centers was only 55%. However, when considering a single phospholipid of a single immunoglobulin isotype, agreement of test results was 83.8%. Isolated positive APA results should be correlated with the clinical history and confirmed by repeat testing.

Alternative cerebrospinal fluid tests to diagnose neurosyphilis in HIV-infected individuals

OBJECTIVE

To identify alternatives to the CSF-Venereal Disease Research Laboratory (VDRL) test for the diagnosis of neurosyphilis in HIV-infected individuals.

METHODS

CSF fluorescent treponemal antibody (FTA) reactivity and % CSF lymphocytes that were B cells in fresh and frozen samples were determined for 47 HIV-infected cases with syphilis and 26 HIV-infected controls. As for serum, CSF fluorescent treponemal antibody reactivity > or =2+ was considered positive. Based on the results in controls and cases with normal CSF measures, cut-offs for elevated CSF B cells were proposed to be > or =9% in fresh and > or =20% in frozen samples. Neurosyphilis was defined as a reactive CSF-VDRL.

RESULTS

CSF-FTA-ABS (absorbed) and CSF-FTA (unabsorbed and undiluted) were 100% sensitive for the diagnosis of neurosyphilis. Elevated % CSF B cells in fresh and cryopreserved samples was specific (100%) but not sensitive (40 and 43%) in post hoc analyses. The results of CSF-FTA and assessment of % CSF B cells together allowed 16% of cases with pleocytosis but nonreactive CSF-VDRL to be diagnosed with neurosyphilis and 26% to be diagnosed as not having neurosyphilis.

CONCLUSION

When the CSF-VDRL is nonreactive, CSF-FTA and % CSF B cells may help exclude or establish the diagnosis of neurosyphilis.

A peptide that shares similarity with bacterial antigens reverses thrombogenic properties of antiphospholipid antibodies in vivo

OBJECTIVE

The factors causing production of antiphospholipid (aPL) antibodies remain unidentified. Recently, studies have shown that aPL and anti-beta2Glycoprotein I (anti-beta2GPI) antibodies with pathogenic properties can be generated with peptides from bacterial and viral origin, that mimic regions of beta2GPI. These data suggest a molecular mimicry between bacterial/viral antigens and self-proteins. In this study we examined the ability of a synthetic peptide (named peptide A, NTLKTPRVGGC) that shares similarity with common bacterial antigens, to reverse aPL-mediated thrombosis in mice in vivo. Peptide A is also found in region I/II of beta2GPI. A scrambled form of peptide A (named scA, GTKGCPNVRLT) was used as a control.

METHODS AND RESULTS

Sera from 29 patients with APS bound to peptide A but not to peptide scA by ELISA in a dose-dependent fashion. Cardiolipin (CL) liposomes inhibited the binding of IgG-APS by ELISA to peptide A by 35% and to CL by 56%. The inhibition of binding to cardiolipin and to peptide A was enhanced by addition of beta2GPI to the liposomes. CL/peptide A liposomes but not peptide A alone inhibited the binding of IgG-APS to peptide A. beta2GPI alone did not inhibit binding of IgG-APS to peptide A, to beta2GPI or to CL. For the in vivo experiments, CD1 mice in groups of 20 were injected with affinity purified aPL antibodies or with control IgG-NHS twice intraperitoneally. Seventy hours after the first injection, and 30 min before the surgical procedure (induction of experimental thrombus) mice were infused i.v. in each group with either peptide A or with peptide scA. The femoral vein of the anesthetized mice were dissected to examine the dynamics of an induced thrombus in treated and control mice. The mean aCL titer of mice injected with aPL was 60 GPL units. Mice treated with aPL and infused with peptide scA produced significantly larger thrombi when compared to mice treated with IgG-NHS and peptide scA (2466+/-462 microm2 vs 772.5+/-626.4 microm2). Treatment with peptide A significantly decreased thrombus size in mice injected with aPL antibodies (1063+/-890 microm2 compared to 2466+/-462 microm2).

CONCLUSION

The data indicates that a synthetic peptide that shares similarity with common bacterial antigens and with regions of beta2GPI is capable to inhibit thrombogenic properties of aPL in mice. This may have important implications in designing new modalities of prevention and/or treatment of thrombosis in APS.

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.

Ein zerebraler Grenzzoneninfarkt nach Allgemeinan�sthesie bei einem Patienten mit erh�hten Antikardiolipinantik�rpern

During the first generalised epileptic attack, a patient suffered a humerus fracture which necessitated an operation. This patient also had a history of spontaneous lung emboli and an elevated anti-cardiolipin plasma level for which coumarin was prescribed but was stopped preoperatively. After induction of general anaesthesia for a total shoulder arthroplasty, the patient became hypotensive and the bispectral index recorded perioperatively dropped to 0. Postoperatively, the patient developed signs of a unilateral borderzone cerebral infarct in the area of the medial cerebral artery. The possible pathomechanisms involved are discussed. In cases of known cerebral pathology intraoperative hypotension should be avoided by at all costs. Patients with increased anti-cardiolipin antibody levels and who suffer from epileptic attacks have an increased risk of thromboembolic events.

Autoantibody Panel Screening in Recurrent Miscarriages

PROBLEM

Antiphospholipid autoantibodies (aPL), antithyroid antibodies and anti-extractable nuclear antigens (anti-ENA) have all been reported to be associated with recurrent miscarriages (RM) and infertility. However, this association remained controversial.

MATERIALS AND METHODS

Fifty-eight women with impaired fertility (38 women with RM and 20 women with infertility, but no miscarriages) and 28 control parous women were screened for seven autoantibodies [antithyroglobulin (aTG), antithyroid peroxidase (aTPO), anticardiolipin (aCL), antiphosphatidyl-serine (aPS), antiprothrombin antibodies (aPT), anti-beta 2 glycoprotein 1 (abeta2GP1), and anti-ENA]. There was no evidence for autoimmune diseases in the patients or the control. The analysis was also performed with several panels of autoantibodies, each of which contained two or more autoantibodies.

RESULTS

Anti-TPO was the only antibody to be associated with RM (P = 0.01). A significant association was found between RM, and autoantibodies in the 'aTG + aTPO + anti-ENA' or 'aTG + aTPO' panels. The 'aTG + aTPO + anti-ENA' panel was also associated with RM when the analysis was performed only on 17 women who had secondary infertility: 10 from the 38 women with RM, and seven from the 20 women with infertility and no miscarriages. A significant association (P < 0.001) was also apparent between anti-CL and anti-PS and infertility compared with the 28 control women.

CONCLUSIONS

RM was associated with autoantibodies to aTPO and the combined panel of aTPO, aTG and anti-ENA, but not with aPL. aPL were associated with infertility.

Reactivity profiles of autoantibodies to different phospholipids and the phospholipid-binding protein beta2-glycoprotein I in patients with clinical symptoms related to thromboembolic and/or vasculopathic events with or without connective tissue diseases

To study the antigenic and epitope specificities of anti-phospholipid Ab in detail, we investigated 177 patients without (62 with APS-related systemic clinical symptoms, 115 with microangiopathies) and 164 patients with connective tissue diseases (CTD). Ab associated with primary APS (pAPS) seem to show a restricted specificity (phospholipid/beta2-GPI-complexes), whereas those in secondary APS (sAPS) react additionaly with pure beta2-GPI. Simultaneously, beta2-GPI-independent Ab were also frequently present in both conditions (50% of all Ab-positive sera). In CTD patients, the reactivity profile "pure beta2-GPI + phospholipid/beta2-GPI-complexes" is significantly associated with clinically manifest sAPS. Comparing cardiolipin and phosphatidylserine as antigenic target, the overall concordance (crossreactivity?) between both assays was lower than expected (52%), being highest in pAPS (87%) and sAPS (65%). Based on these results, a two-step procedure for reliable serological diagnosis of APS could be recommended: Ab-screening using a mix of phospholipids complexed with beta2-GPI (sensitivity > 90% for Ab concentrations above 20 U/ml) followed by an assay allowing the simultaneous detection of all relevant antigenic and epitope specificities.

Preparation and characterization of diacetylene polymerized liposomes for detection of autoantibodies

Affinity diacetylene liposomes were prepared with 10,12-tricosadiynoic acid and cardiolipin as the affinity ligand for anticardiolipin antibodies at a molar ratio of 80:20. Polymerization was carried out under UV irradiation, and the color transitions were monitored by visible absorption spectroscopy. Peaks at 635 nm (blue form), 540 nm (purple form), and 480 nm (red form) were observed as a function of time. These polymerized liposomes were used in a noncompetitive immunoassay for detection of anticardiolipin antibodies. Color changes were observed when reference serum containing specific immunoglobulin G, IgG, was added to polymerized liposome dispersions. The colorimetric signal due to IgG adsorption on the liposome surface was quantified as a colorimetric response defined as the change in percentage of blue color related to the initial percentage of blue color in the solutions. The colorimetric response was 10 times higher for specific IgG compared with nonspecific ones. These results suggest the unique potentialities of affinity diacetylene polymerized liposomes in the development of biosensors for diagnosis of autoimmune diseases.

Matrix effects in clinical immunoassays and the effect of preheating and cooling analytical samples

Immunological reactions are influenced by various factors including antigens, antibodies and other variables. We focused on two items: i) matrix effects, especially of detergents and ii) temperature effects: preheating sera, especially effects on rheumatoid factor (RF) measurement and false-positive reactions in ELISAs, and cold storage of sera, especially effects on complement. Among various additives, detergents affected the agglutination reaction for fecal hemoglobin and hepatitis B surface (HBs) antigen. Some of the detergents examined abolished these antigenicities, however, polyethylenglycols enhanced the reactions. Heat-inactivation of sera at 56°C for 30 min was employed in serological testing. However, in RF measurement, 10 min of preheating was sufficient to abolish C1q (subcomponent of C1), which could participate in the agglutination reaction. In ELISA for antibodies, false-positive reactions were caused by preheating sera. By the analyses of assays for antibodies to hepatitis C virus (HCV) and cardiolipin, it was found that they were induced by immunoglobulin G (IgG) modified by preheating. Cold storage induced activation of complement (cold activation) in anti-HCV antibody positive sera. CH50 titers in the sera were lowered by one cycle of freezing at −20°C and thawing, and the decrease was affected by the containers.

Anticardiolipin beta2-glycoprotein I antibody: is a high titer related to unfavorable pregnancy outcome?

We present the clinical characteristics of pregnancy histories and subsequent pregnancy outcomes of 13 women who tested positive for anticardiolipin beta2-glycoprotein I antibody (aCLbeta2GPI). Six of the 13 women had a history of recurrent spontaneous abortion (RSA). The prevalence of aCLbeta2GPI syndrome among women with RSA was very low (2.1%). Other women with aCLbeta2GPI were identified by the presence of a biological false-positive serological test for syphilis, intrauterine growth restriction (IUGR), and a history of thrombosis. However, serum aCLbeta2GPI titers in the 13 women varied, with a wide range from 3.6 to 1468 U/mL. Their pregnancy histories, subsequent pregnancy outcomes, and complications were compared according to the classification of serum aCLbeta2GPI titers as low, moderate, or high. The history of second trimester fetal death was found only in women with high serum aCLbeta2GPI titers. All women with high serum aCLbeta2GPI titers experienced severe maternal-fetal complications such as IUGR, fetal distress, systemic thromboembolism, and neonatal sequelae in subsequent pregnancies.

Prothrombotic Factors in Children with Otitis Media and Sinus Thrombosis

OBJECTIVE

Venous sinus thrombosis (VST) is the second most common intracranial complication of acute otitis media (AOM). There is some evidence that hereditary and acquired prothrombotic disorders are risk factors for VST. The aim of the present study was to evaluate whether children with AOM complicated VST have a prothrombotic tendency, which might have important therapeutic and preventive implications.

STUDY DESIGN

Retrospective.

METHODS

The files of children hospitalized at Schneider Children's Medical Center of Israel, a tertiary referral center, from 1999 to 2002, because of AOM complicated by acute mastoiditis and VST were reviewed. All children underwent laboratory work-up for hypercoagulability.

RESULTS

Seven children met the study criteria. Of these, five had prothrombotic disorders, namely elevated levels of lipoprotein apolipoprotein (Lp[a]) (n = 4), antibodies to beta 2-glycoprotein and to cardiolipin (markers of antiphospholipid syndrome) (n = 4), and heterozygosity for factor V Leiden mutation (n = 1). One child had three abnormalities, two children had two abnormalities, and two children had one abnormality.

CONCLUSIONS

A prothrombotic tendency may exist in children with AOM complicated by mastoiditis and VST. Further studies are needed to evaluate its extent.