Rohan Willis

14th International Congress on Antiphospholipid Antibodies: task force report on antiphospholipid syndrome treatment trends.

Antiphospholipid Syndrome (APS) is characterized by vascular thrombosis and/or pregnancy morbidity occurring in patients with persistent antiphospholipid antibodies (aPL). The primary objective of the APS Treatment Trends Task Force, created as part of the 14th International Congress on aPL, was to systematically review the potential future treatment strategies for aPL-positive patients. The task force chose as future clinical research directions: a) determining the necessity for controlled clinical trials in venous thromboembolism with the new oral direct thrombin or anti-factor Xa inhibitors pending the results of the ongoing rivaroxaban in APS (RAPS) trial, and designing controlled clinical trials in other forms of thrombotic APS; b) systematically analyzing the literature as well as aPL/APS registries, and creating specific registries for non-warfarin/heparin anticoagulants; c) increasing recruitment for an ongoing primary thrombosis prevention trial, and designing secondary thrombosis and pregnancy morbidity prevention trials with hydroxychloroquine; d) determining surrogate markers to select patients for statin trials; e) designing controlled studies with rituximab and other anti-B-cell agents; f) designing mechanistic and clinical studies with eculizumab and other complement inhibitors; and g) chemically modifying peptide therapy to improve the half-life and minimize immunogenicity. The report also includes recommendations for clinicians who consider using these agents in difficult-to-manage aPL-positive patients.

Effect of hydroxychloroquine treatment on pro-inflammatory cytokines and disease activity in SLE patients: data from LUMINA (LXXV), a multiethnic US cohort:

Objective: We sought to determine the effect of hydroxychloroquine therapy on the levels proinflammatory/prothrombotic markers and disease activity scores in patients with systemic lupus erythematosus (SLE) in a multiethnic, multi-center cohort (LUMINA). Methods: Plasma/serum samples from SLE patients (n = 35) were evaluated at baseline and after hydroxychloroquine treatment. Disease activity was assessed using SLAM-R scores. Interferon (IFN)-α2, interleukin (IL)-1β, IL-6, IL-8, inducible protein (IP)-10, monocyte chemotactic protein-1, tumor necrosis factor (TNF)-α and soluble CD40 ligand (sCD40L) levels were determined by a multiplex immunoassay. Anticardiolipin antibodies were evaluated using ELISA assays. Thirty-two frequency-matched plasma/serum samples from healthy donors were used as controls. Results: Levels of IL-6, IP-10, sCD40L, IFN-α and TNF-α were significantly elevated in SLE patients versus controls. There was a positive but moderate correlation between SLAM-R scores at baseline and levels of IFN-α (p = 0.0546). Hydroxychloroquine therapy resulted in a significant decrease in SLAM-R scores (p = 0.0157), and the decrease in SLAM-R after hydroxychloroquine therapy strongly correlated with decreases in IFN-α (p = 0.0087). Conclusions: Hydroxychloroquine therapy resulted in significant clinical improvement in SLE patients, which strongly correlated with reductions in IFN-α levels. This indicates an important role for the inhibition of endogenous TLR activation in the action of hydroxychloroquine in SLE and provides additional evidence for the importance of type I interferons in the pathogenesis of SLE. This study underscores the use of hydroxychloroquine in the treatment of SLE.

A prospective open-label pilot study of fluvastatin on proinflammatory and prothrombotic biomarkers in antiphospholipid antibody positive patients

Objective To determine if proinflammatory and prothrombotic biomarkers are differentially upregulated in persistently antiphospholipid antibody (aPL)-positive patients, and to examine the effects of fluvastatin on these biomarkers. Methods Four groups of patients (age 18–65) were recruited: (a) primary antiphospholipid syndrome; (b) systemic lupus erythematosus (SLE) with antiphospholipid syndrome (APS) (SLE/APS); (c) persistent aPL positivity without SLE or APS (Primary aPL); and (d) persistent aPL positivity with SLE but no APS (SLE/aPL). The frequency-matched control group, used for baseline data comparison, was identified from a databank of healthy persons. Patients received fluvastatin 40 mg daily for 3 months. At 3 months, patients stopped the study medication and they were followed for another 3 months. Blood samples for 12 proinflammatory and prothrombotic biomarkers were collected monthly for 6 months. Results Based on the comparison of the baseline samples of 41 aPL-positive patients with 30 healthy controls, 9/12 (75%) biomarkers (interleukin (IL)-6, IL1β, vascular endothelial growth factor (VEGF), tumour necrosis factor (TNF)-α, interferon (IFN)-α, inducible protein-10 (IP10), soluble CD40 ligand (sCD40L), soluble tissue factor (sTF) and intracellular cellular adhesion molecule (ICAM)-1) were significantly elevated. Twenty-four patients completed the study; fluvastatin significantly and reversibly reduced the levels of 6/12 (50%) biomarkers (IL1β, VEGF, TNFα, IP10, sCD40L and sTF). Conclusions Our prospective mechanistic study demonstrates that proinflammatory and prothrombotic biomarkers, which are differentially upregulated in persistently aPL-positive patients, can be reversibly reduced by fluvastatin. Thus, statin-induced modulation of the aPL effects on target cells can be a valuable future approach in the management of aPL-positive patients.

Standardization of antiphospholipid antibody testing--historical perspectives and ongoing initiatives.

The measurement of antiphospholipid antibodies (aPL) has been an important aspect of antiphospholipid syndrome (APS) characterization since the disease was first described in the 1980s. Despite significant efforts geared toward the standardization of immunoassays that measure anticardiolipin antibodies and anti-β2-glycoprotein I spanning three decades, there are still reports of significant interassay and interlaboratory variation in the results of these assays. At the recent 13th International Congress on Antiphospholipid Antibodies (APLA 2010, April 13-16, 2010, Galveston, TX), a task force composed of internationally recognized experts in the field of APS was formed to address these issues. In this review, we discuss approaches that have been used in the past to achieve harmonization among aPL immunoassays as well as the ongoing efforts of the APLA task force. Our review also highlights the importance of cutoff determination in aPL assays and the clinical significance of positive aPL results of varying magnitudes.

Complement C5-inhibitor rEV576 (coversin) ameliorates in-vivo effects of antiphospholipid antibodies.

Activation of the complement cascade is an important mechanism for antiphospholipid antibody-mediated thrombosis. We examined the effects of rEV576 (coversin), a recombinant protein inhibitor of complement factor 5 activation, on antiphospholipid antibody-mediated tissue factor up-regulation and thrombosis. Groups of C57BL/6J mice (n = 5) received either IgG from a patient with antiphospholipid syndrome (APS) or control IgG from normal human serum (NHS). Each of these groups of mice had IgG administration preceded by either rEV576, or phosphate buffer control. For each of the four treatment groups, the size of induced thrombus, tissue factor activity in carotid homogenates, anticardiolipin and anti-β2glycoprotein I (anti-β2GPI) levels were measured 72 h after the first injection. Mice treated with IgG-APS had significantly higher titers of anticardiolipin antibodies and anti-β2GPI at thrombus induction compared with those treated with IgG-NHS. The IgG-APS/phosphate buffer treatment induced significantly larger thrombi and tissue factor activity compared with other groups. Mice treated with IgG-APS/rEV576 had significantly smaller thrombi and reduced tissue factor activity than those treated with IgG-APS/phosphate buffer. The data confirm involvement of complement activation in antiphospholipid antibody-mediated thrombogenesis and suggest that complement inhibition might ameliorate this effect.

Acquired and Inherited Thrombophilia Disorders in Pregnancy

Thromboembolism is the leading cause of antepartum and postpartum maternal mortality. The presence of antiphospholipid antibodies is responsible for many pregnancy losses and other morbidities in pregnant women, and is the most prevalent and treatable cause of acquired thrombophilia in pregnancy. There is also evidence that women with thrombophilia are at increased risk not only of pregnancy-related venous thromboembolism but other vascular pregnancy complications. Many studies have examined the association between thrombophilia and pregnancy complications. This article reviews the most up-to-date knowledge of prevalence, pathogenesis, and diagnosis of acquired and inherited thrombophilias and their relationship and association with pregnancy complications.

The Journey of Antiphospholipid Antibodies From Cellular Activation to Antiphospholipid Syndrome

Pathogenic antiphospholipid antibodies (aPL) are the driving factors of recurrent pregnancy loss and thrombosis that characterize antiphospholipid syndrome (APS). Current evidence indicates that aPL induce a procoagulant phenotype in the vasculature and abnormal cellular proliferation and differentiation in placental tissues to cause the typical clinical features; however, the molecular mechanisms underlying these processes remain incompletely understood. Inflammation serves as a necessary link between the observed procoagulant phenotype and actual thrombus development and is an important mediator of the placental injury in APS patients. However, the underlying mechanisms for these events have also not been fully elucidated. In this review, we will outline the available data that give us our current understanding of the pathophysiology of APS, especially as it relates to the development of thromboembolic and obstetric pathological phenomena in these patients. We will also describe the intracellular signaling pathways activated by aPL in various cellular subtypes and outline the current evidence linking these pathways to clinical phenotypes. Finally, we will discuss the implications of distinct molecular patterns defining clinical phenotypes of APS patients.

International standards for IgG and IgM anti-β2glycoprotein antibody measurement

International standards for anti-beta2 glycoprotein I (anti-β2GPI) testing are needed. We evaluated the suitability of polyclonal/monoclonal candidate reference materials (RM) for the assay. IgG/IgM anti-β2GPI were affinity-purified (AP) from high-positive antiphospholipid syndrome sera and IgG from HCAL clone supernatant. Igs were tested for purity by SDS-PAGE, pooled, concentrated, sterile-filtered and the protein concentration determined. One unit was defined as the binding activity of 1 µg/ml of AP anti-β2GPI Ig. IgG/IgM RM were each assigned a unit value using the respective AP material as a calibrator. Polyclonal/monoclonal RM and 30 samples were evaluated for linearity, unit equivalency and commutability. Polyclonal AP material was assigned a value of 100 U IgG and 15 U IgM anti-β2GPI, respectively. IgG-RM had a value of 270 IgG and the IgM-RM of 220.3 IgM anti-β2GPI U. The linearity (R2) of each RM curve for the various assays ranged from 0.96 to 0.99. Commutability samples fit very well within 95% prediction intervals and had excellent correlation when comparing assays. IgG and IgM polyclonal and IgG monoclonal RM displayed excellent linearity and commutability, being good candidates for better standardization of anti-β2GPI immunoassays.

Hydroxychloroquine in the primary thrombosis prophylaxis of antiphospholipid antibody positive patients without systemic autoimmune disease

Objective The objective of this study was to determine the efficacy of hydroxychloroquine (HCQ) in the primary thrombosis prevention of antiphospholipid antibody (aPL)-positive patients with no other systemic autoimmune diseases. Methods Under the auspices of Antiphospholipid Syndrome Alliance for Clinical Trials and International Networking, a multicenter, international, randomized controlled trial (RCT) was initiated, in which persistently aPL-positive but thrombosis-free patients without systemic autoimmune diseases were randomized to receive HCQ or no treatment in addition to their standard regimen. The primary objective was the efficacy of HCQ in preventing the first thrombosis. The secondary objectives were the thrombosis incidence rate, and the effects of HCQ on aPL profile and mortality rate. Patients were risk-stratified based on antiplatelet agent use. The goal was to follow patients every 6 months for 5 years. Results We recruited 20 persistently aPL-positive patients (female: 19, mean age: 46.6 ± 9.9 years, and baseline antiplatelet medication: 14); 9/20 were randomized to HCQ. During the mean follow-up of 1.7 years, no patients developed thrombosis or a serious adverse event. The study was terminated early due to the low recruitment rate, exacerbated by the prolonged manufacturing shortage and significant price increase of HCQ in the United States. Conclusion Given that a small number of patients with a relatively short follow-up were enrolled in our RCT, and no patients developed thrombosis, we cannot accurately assess the effectiveness of HCQ for primary thrombosis prevention in persistently aPL-positive patients with no other systemic autoimmune diseases. Our experience suggests that conducting an international RCT, especially without pharmaceutical support, is an extremely challenging undertaking.

Clinical significance and correlations between anti-β2 glycoprotein I IgA assays in antiphospholipid syndrome and/or systemic lupus erythematosus.

BACKGROUND The objective of this investigation was to examine the clinical significance of IgA anti-β2 glycoprotein I (anti-β2GPI) antibodies and the inter-assay relationships between kits for their determination. METHODS Serum samples from 269 patients with clinical diagnoses of systemic lupus erythematosus (SLE) and/or antiphospholipid syndrome (APS), individuals positive for antiphospholipid antibodies (aPL) with or without APS or SLE, and 182 controls were tested for anti-β2GPI IgA antibodies using kits from four manufacturers. RESULTS The positivity rates for the different IgA anti-β2GPI antibody kits varied in the disease groups; 7.8-14.7% (SLE only), 12.0-15.7% (SLE and APS/aPL), 14.7-58.8% (APS only), and 17.4-52.2% (aPL only). Kappa agreements between any 2 kits within disease groups were also variable and ranged from 0.25-1.00 (SLE), 0.18-1.00 (SLE and APS/aPL), 0.22-0.94 (APS only), and 0.32-0.91 (aPL only). Univariate analyses also showed variable relative risks for specific APS clinical manifestations with the different kits evaluated. Overall, diagnostic and predictive values for IgA anti-β2GPI antibodies are kit-dependent; therefore results are not interchangeable. While all 4 kits seem able to predict venous thrombosis tolerably well, there was a variable performance in predicting pregnancy related morbidity. CONCLUSIONS Efforts to standardize these assays are highly needed prior to their formal adoption in routine clinical evaluation.