Maria Gerosa

Anti-DNA antibodies: a diagnostic and prognostic tool for systemic lupus erythematosus?

The clinical impact of anti-DNA antibodies lies on their diagnostic power for systemic lupus erythematosus (SLE), being a formal classification criterion. In spite of such a disease association, low-avidity anti-DNA antibodies might also be part of the natural autoantibody repertoire. Their switch to pathogenic high-avidity autoantibodies is the result of the autoimmune process leading to SLE. Anti-DNA antibodies were shown to play a role in SLE pathogenesis and particularly in kidney damage. Accordingly, antibody titres might fluctuate in relation to disease activity, but their prognostic value for flares is still debated. Several methods for anti-DNA detection were described and there is evidence that the assays identify different antibodies with different prognostic value. The results of a multicenter study on four different routine tests for anti-dsDNA antibody detection showed that: (i) Farr assay displays the best diagnostic specificity/sensitivity for SLE, followed by Crithidia luciliae method (CLIFT), (ii) the new generation of solid phase assay (EliA) shows an increased sensibility versus the classical enzyme linked immune assay (ELISA) but a decreased specificity. Antibody titre detected by EliA and Farr assay correlated with disease activity. These findings would suggest that more than one assay should be useful for SLE diagnosis and monitoring.

Patients with antiphospholipid syndrome display endothelial perturbation

BACKGROUND There is strong evidence that antiphospholipid antibodies (aPL) perturb endothelium both in vitro and in experimental animal models. by inducing a vasculopathy and an endothelial pro-inflammatory/coagulant phenotype. However, few contrasting studies raised the issue about the possibility to detect a comparable endothelial perturbation in anti-phospholipid syndrome (APS) patients. The aim of this observational case-control study was to evaluate several parameters of endothelial perturbation in patients with APS and without any other atherosclerosis risk factor. PATIENTS AND METHODS We investigated plasma levels of soluble adhesion molecules (s-ICAM-1, s-VCAM-1, s-E-selectin), soluble thrombomodulin (sTM), von Willebrand factor (vWF) and tissue plasminogen activator (t-PA) by solid-phase assays in 40 selected APS patients and 40 age- and sex-matched healthy subjects. In addition, we evaluated circulating endothelial cells by flow cytometry and brachial artery flow-mediated vasodilation. Patients and controls were free of conditions known to affect both the biological and the functional endothelial parameters. RESULTS Plasma levels of sTM, s-E-selectin and s-VCAM-1 did not differ from controls, while a significant increase in s-ICAM-1 (P = 0.029), t-PA (P = 0.003) and vWF titres (P = 0.002) was found. Circulating mature endothelial cells were also significantly higher in patients than in controls (P = 0.05) and decreased during both vitamin K antagonists (P = 0.001) and antiplatelet (P = 0.032) treatments. Mean brachial artery flow-mediated vasodilation responses were significantly impaired compared to healthy subjects (P = 0.0001). CONCLUSIONS As a whole these findings indicate that APS patients display an endothelial perturbation in the absence of other detectable traditional risk factors for atherosclerosis.

Impaired serum cholesterol efflux capacity in rheumatoid arthritis and systemic lupus erythematosus

Objectives The marked cardiovascular risk in autoimmune diseases is only partly explained. The capacity of high-density lipoproteins (HDL) to promote cell cholesterol efflux is a property with a well-known anti-atherogenic significance, but is also involved in functional modulation of endothelial and immune cells. The aim of this work was to evaluate HDL functionality with respect to cell cholesterol efflux in rheumatoid arthritis (RA) and systemic lupus erythemathosus (SLE) patients. Methods We evaluated serum cholesterol efflux capacity (CEC) of apoB-depleted serum, which mainly reflects HDL activity, from 30 RA and 30 SLE patients, and from 30 healthy controls by radioisotopic ex-vivo systems discriminating between the specific pathways of cholesterol efflux. Results RA patients presented impairment of ATP-binding cassette G1-mediated CEC that correlated with disease activity. SLE patients showed a more complex pattern of modifications unrelated to disease activity, with marked reduction of ATP-binding cassette G1-mediated CEC and impairment of ATP-binding cassette A1-mediated CEC. The relationship between specific pathways of CEC values and serum total HDL differed between groups and there was no relationship with autoantibody profile or current therapy. Conclusions CEC is impaired in RA and SLE, with a specific mechanism pattern in each disease not depending on serum HDL levels. These findings provide a new mechanism for the increased atherosclerotic risk in RA and SLE patients.

Antiphospholipid syndrome in 2014: more clinical manifestations, novel pathogenic players and emerging biomarkers

The clinical spectrum of the anti-phospholipid syndrome (APS) is not limited to vascular thrombosis or miscarriages but includes additional manifestations that cannot be explained solely by a thrombophilic state. Anti-cardiolipin, anti-beta2 glycoprotein I (anti-β2GPI) and lupus anticoagulant (LA) assays are not only the formal diagnostic and classification laboratory tools but also parameters to stratify the risk to develop the clinical manifestations of the syndrome. In particular, anti-β2GPI antibodies reacting with an immunodominant epitope on domain I of the molecule were reported as the prevalent specificity in APS patients, correlating with a more aggressive clinical picture. Several laboratory assays to improve the diagnostic and predictive power of the standard tests have been proposed. Plates coated with the phosphatidylserine-prothrombin complex for detecting antibodies represent a promising laboratory tool correlating with LA and with clinical manifestations. Anti-phospholipid antibodies can be found in patients with full-blown APS, in those with thrombotic events or obstetric complications only or in asymptomatic carriers. An inflammatory second hit is required to increase the presence of β2GPI in vascular tissues, eventually triggering thrombosis. Post-transcriptional modifications of circulating β2GPI, different epitope specificities or diverse anti-β2GPI antibody-induced cell signaling have all been suggested to affect the clinical manifestations and/or to modulate their occurrence.

Endothelium as a target for antiphospholipid antibodies.

Several, and not necessarily alternative, pathogenic mechanisms have been suggested to sustain the thrombophilic diathesis of the anti-phospholipid syndrome. Among them, interference of anti-phospholipid antibodies with cell acting in the coagulation cascade likely plays a major role. Anti-phospholipid antibodies have been shown to react with endothelial cells mainly by reacting with beta 2 glycoprotein I expressed on the cell membrane surface. Beta 2 glycoprotein I can adhere to endothelial cell surface through the Annexin II receptor and through negatively charged structures (heparin-like molecules) that are bound by the phospholipid-binding site of the molecule. The autoantibody binding involves a yet unknown receptor that activates a signalling pathway able to translocate NFkappaB from the cytoplasm to the nucleus and to activate genes for adhesion molecule, pro-inflammatory cytokine and Tissue Factor up-regulation. The ultimate effect is the induction of a pro-inflammatory and a pro-coagulant endothelial phenotype that has been reproduced both in vitro and in vivo experimental models. Additional effects of anti-phospholipid-mediated endothelial cell activation are the interference with the protein C/S system, with the Annexin V binding, the up-regulation of endothelin I synthesis and the induction of apoptosis. Altogether these effects cooperate in switching endothelium from an anti-coagulant to a pro-coagulant surface.

Cardiac involvement in systemic autoimmune diseases

The heart and the vascular system are frequent and characteristic targets of several systemic autoimmune diseases, in particular Systemic Lupus Erythematosus (SLE), Rheumatoid Arthritis (RA) and Systemic Sclerosis (SSc). In this chapter we review the classic cardiac abnormalities and the more recent data about cardiovascular involvement as part of a major disease complication determining a substantial morbidity and mortality.In addition to the classic cardiac abnormalities involving the heart structures, acute and chronic ischemic heart disease and cerebrovascular accidents are threatening clinical manifestations of SLE and RA associated to an early accelerated atherosclerosis. Immune-mediated inflammation is now recognized as an important factor involved in the pathogenesis of atherosclerosis.Ongoing clinical studies are being devised to find specific risk factors associated with systemic autoimmune diseases and/or treatment regimens. Hopefully, prophylactic measures should be available within the next few years.

New Tests to Detect Antiphospholipid Antibodies: Anti-Domain I Beta-2-Glycoprotein-I Antibodies

Beta-2 glycoprotein I (β2GPI) is the main antigenic target for antiphospholipid antibodies (aPL), the serological markers of antiphospholipid syndrome (APS). Domain I (DI) of β2GPI has lately been identified as the main epitope targeted by antibodies reacting against β2GPI. DI is a cryptic epitope, becoming available for autoantibody binding when β2GPI opens from a circular to a fish-hook configuration. Antibodies targeting β2GPI-DI are more frequently detected in patients with a full-blown syndrome than in asymptomatic aPL carriers or in patients with infectious diseases that have reactivity toward the whole molecule. Interestingly, anti-DI antibodies are strongly positively correlated with thrombotic and pregnancy manifestations, enabling identification of patients at higher risk of clinical events. However, available tests to detect anti-DI antibodies still lack standardization. Moreover, some APS patients develop antibodies reacting against β2GPI epitopes other than DI, suggesting that other anti-β2GPI antibody subsets may be clinically relevant. Available evidence on anti-DI antibodies in APS is herein critically reviewed.

Clinical Characterization of Antiphospholipid Syndrome by Detection of IgG Antibodies Against β2‐Glycoprotein I Domain 1 and Domain 4/5: Ratio of Anti–Domain 1 to Anti–Domain 4/5 As a Useful New Biomarker for Antiphospholipid Syndrome

It has been suggested that only antibodies against domain 1 (D1) of β2‐glycoprotein I (β2GPI) are pathogenic and diagnostic. The role of antibodies against other β2GPI domains is still debated. This study was undertaken to evaluate the clinical relevance of domain specificity profiling of anti‐β2GPI IgG antibodies in antiphospholipid syndrome (APS) patients and in control groups of patients with systemic autoimmune rheumatic diseases and in asymptomatic antiphospholipid antibody (aPL) carriers.

Updating on the Pathogenic Mechanisms 5 of the Antiphospholipid Antibodies-Associated Pregnancy Loss

Anti-phospholipid antibodies (aPL) are risk factor for recurrent pregnancy loss and obstetrical complications. The mechanisms of aPL-mediated pregnancy failure are still a matter of research. Although aPL are associated with thrombosis, thrombotic events cannot explain all the miscarriages. There is evidence for a direct in vitro aPL effect on the trophoblast as shown by their binding; reduction of proliferation, human chorionic gonadotrophin release, in vitro invasiveness, adhesion molecule expression; and increased apoptosis. Such a direct reactivity is supported by the expression of beta2 glycoprotein (β2GP) I on trophoblast cell membranes. aPL/anti-β2GPI antibodies also bind to human decidual/endometrial cells in vitro and induce a pro-inflammatory phenotype. APL-mediated inflammatory processes at the placental level are apparently responsible for fetal loss at least in animal models. Both complement activation and pro-inflammatory cytokine/chemokine secretion have been shown to play a role. More recently, complement-induced tissue factor expression on infiltrating neutrophils was described as an additional pathogenic mechanisms mediated by aPL. As a whole, these findings do suggest that aPL may induce a defective placentation by acting at different levels without involving necessarily thrombotic events.

Brief report: successful pregnancies but a higher risk of preterm births in patients with systemic sclerosis: an Italian multicenter study

OBJECTIVE To assess fetal and maternal outcomes in women with systemic sclerosis (SSc). METHODS Prospectively collected data on 99 women with SSc from 25 Italian centers were analyzed retrospectively. Women with SSc were observed during 109 pregnancies (from 2000 to 2011), and outcomes were compared to those in the general obstetric population (total of 3,939 deliveries). The maternal age at conception was a mean ± SD 31.8 ± 5.3 years, and the median disease duration at conception was 60 months (range 2-193 months). RESULTS SSc patients, compared to the general obstetric population, had a significantly increased frequency of preterm deliveries (25% versus 12%) and severe preterm deliveries (<34 weeks of gestation) (10% versus 5%), intrauterine growth restriction (6% versus 1%), and babies with very-low birth weight (5% versus 1%). Results of multivariable analysis showed that corticosteroid use was associated with preterm deliveries (odds ratio [OR] 3.63, 95% confidence interval [95% CI] 1.12-11.78), whereas the use of folic acid (OR 0.30, 95% CI 0.10-0.91) and presence of anti-Scl-70 antibodies (OR 0.26, 95% CI 0.08-0.85) were protective. The disease remained stable in most SSc patients, but there were 4 cases of progression of disease within 1 year from delivery, all in anti-Scl-70 antibody-positive women, 3 of whom had a disease duration of <3 years. CONCLUSION Women with SSc can have successful pregnancies, but they have a higher-than-normal risk of preterm delivery, intrauterine growth restriction, and babies with very-low birth weight. Progression of the disease during or after pregnancy is rare, but possible. High-risk multidisciplinary management should be standard for these patients, and pregnancy should be avoided in women with severe organ damage and postponed in women with SSc of recent onset, particularly if the patient is positive for anti-Scl-70 antibodies.