A novel mechanism of thrombosis in antiphospholipid antibody syndrome

Anesthetic Management of a Jehovah's Witness Patient for Coronary Artery Bypass Grafting With Antiphospholipid Antibody Syndrome and Renal Transplant

Anesthesia for cardiac surgical patients with antiphospholipid antibody syndrome (APLS) presents challenges with monitoring anticoagulation during cardiopulmonary bypass. Additionally, this condition is associated with other autoimmune diseases and comorbidities that need to be considered in caring for these patients, and there is minimal evidence for specific strategies during cardiac surgery. Separately, Jehovah's Witness (JW) patients typically do not consent to receiving blood products, presenting an additional challenge for resuscitation during cardiac surgery and especially in the context of APLS. We present our approach to the anesthetic management of a JW patient with systemic lupus erythematosus (SLE) complicated by APLS, thrombocytopenia, and renal failure with history of renal transplant who presented for coronary artery bypass surgery. Management strategies we recommend include administration of antifibrinolytics after heparinization to mitigate bleeding risk and interdisciplinary management with the perfusion, intensive care, surgical, and nephrology teams.

Antiphospholipid antibodies induce proinflammatory and procoagulant pathways in endothelial cells

Antiphospholipid syndrome (APS) is an autoimmune thrombophilia characterized by recurrent thrombotic events and/or pregnancy morbidity in the presence of antiphospholipid antibodies detected either as anti-cardiolipin, anti-β2 Glycoprotein I (anti-β2GPI) or Lupus anticoagulant (LA). Endothelial deregulation characterizes the syndrome. To address gene expression changes accompanying the development of autoimmune phenotype in endothelial cells in the context of APS, we performed transcriptomics analysis in Human Umbilical Vein Endothelial Cells (HUVECs) stimulated with IgG from APS patients and β2GPI, followed by intersection of RNA-seq data with published microarray and ChIP-seq results (Chromatin Immunoprecipitation). Our strategy revealed that during HUVEC activation diverse signaling pathways such as TNF-α, TGF-β, MAPK38, and Hippo are triggered as indicated by Gene Ontology (GO) classification and pathway analysis. Finally, cell biology approaches performed side-by-side in naïve and stimulated cultured HUVECs, as well as, in placenta specimens derived from Healthy donors (HDs) and APS-patients verified the evolution of an APS-characteristic gene expression program in endothelial cells during the initial stages of the disease's development.

Bilateral pulmonary embolism associated with peripheral blood eosinophilia and positive antiphospholipid antibodies in a patient with cellulitis

Key Clinical Message

This report described the pathophysiology, diagnostic workup, and management of thrombosis possibly associated with peripheral blood eosinophilia and transient positive antiphospholipid antibodies in the setting of cellulitis.

Abstract

Peripheral blood eosinophilia is a risk factor for thrombosis and the presence of other prothrombotic factors such as antiphospholipid antibodies can potentiate that risk. The authors present a case of acute pulmonary embolism which developed at the peak of eosinophilia, later found to have transient positive antiphospholipid antibodies in a male patient with right lower limb cellulitis and a history of intravenous drug abuse. This report illustrates the pathophysiology, diagnosis workup, and therapeutic options of thrombosis possibly associated with peripheral blood eosinophilia and positive antiphospholipid antibodies, which include anticoagulants, corticosteroids, and immunosuppressants. Clinicians should be aware of this possible association which may guide the choice and duration of anticoagulants. Although direct oral anticoagulants are effective anticoagulants in various thromboembolic events, studies showed unfavorable outcomes for their use in antiphospholipid syndrome.

Lupus Anticoagulant and Anticardiolipin Antibody IgG are Associated with Increased Atherosclerosis at the Suprainguinal Elastic and Infrainguinal Muscular Arteries in the Abdomen and Lower Extremities

Purpose

Whether antiphospholipid antibodies (aPLs) cause atherosclerosis in certain arteries with specific compositions and locations remains unknown. We investigated the relationship between aPLs and their association with locations of atherosclerosis in the arteries of the abdomen and lower extremities.

Methods

Of 2273 patients, 697 who underwent computed tomography angiography of the abdomen and lower extremities and aPL evaluation were included. Atherosclerosis distribution score (ADS) was employed to quantify atherosclerosis severity. Multiple linear regression analysis was performed using the ADS of the suprainguinal elastic and infrainguinal muscular arteries as dependent variables and all aPLs, conventional risk factors of atherosclerosis, and coagulation-related factors as independent variables.

Results

In the suprainguinal elastic and infrainguinal muscular arteries, common risk factors for higher ADS were age, smoking, hypertension, higher glycated hemoglobin, male sex, decreased protein S, and increased homocysteine. Lupus anticoagulant (LA) and increased triglyceride level in the suprainguinal elastic arteries and anticardiolipin antibody (aCL) immunoglobulin (Ig)G, longer alcohol consumption duration, and increased fibrinogen level in the infrainguinal muscular arteries were also risk factors for higher ADS.

Conclusion

LA and aCL IgG were associated with atherosclerosis in the suprainguinal elastic and infrainguinal muscular arteries, respectively. aPLs could predict the location of atherosclerosis.

Risk factors for the flare of systemic lupus erythematosus and its influence on prognosis: a single-center retrospective analysis

OBJECTIVES

To explore the risk factors for systemic lupus erythematosus (SLE) flare and their impact on prognosis.

METHODS

The clinical characteristics, laboratory results, and treatment plans of 121 patients with SLE flare were retrospectively analyzed. Ninety-eight SLE outpatients with sustained remission during the same period were selected as controls. Logistic multivariate regression analysis was employed to screen for risk factors for SLE flare.

RESULTS

Infection, thrombocytopenia, arthritis, anti-nucleosome antibodies positive, anti-β2-glycoprotein I (IgG) antibodies positive, and patient's self-discontinuation of medicine maintenance therapy might be risk factors for SLE flare. Patients who discontinued medicine maintenance therapy by themselves had a significantly higher rate of severe SLE flare than patients with regular medicine maintenance therapy (P = 0.033). The incidence of anemia associated with SLE (P = 0.001), serositis (P = 0.005), and pulmonary hypertension (P = 0.003) in patients who discontinued medicine maintenance therapy were significantly higher than patients with regular medicine maintenance therapy. SLE patients with regular medicine maintenance therapy for less than 3 years had a higher risk of pulmonary hypertension than those with regular medicine maintenance therapy longer than 3 years (P = 0.034).

CONCLUSIONS

The accompanying thrombocytopenia, arthritis, anti-nucleosome antibodies positive and anti-β2-glycoprotein I (IgG) antibodies positive at the onset of SLE may affect the prognosis of SLE. Patient's self-discontinuation of medicine maintenance therapy is the main cause of SLE flare, which may induce severe flare in SLE patients and lead to a significantly higher incidence of pulmonary hypertension.

Non-Criteria Manifestations of Juvenile Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder mainly characterised by increased risks of thrombosis and pregnancy morbidity and persistent positive test results for antiphospholipid antibodies (aPLs). The criteria for diagnosing juvenile APS have yet to be validated, while the Sydney classification criteria do not contain several non-thrombotic clinical manifestations associated with the presence of aPLs. As such, difficulties have been encountered in the diagnosis of patients who have no certain thrombotic occlusions. Moreover, extra-criteria manifestations (i.e., clinical manifestations not listed in the classification criteria), including neurologic manifestations (chorea, myelitis and migraine), haematologic manifestations (thrombocytopenia and haemolytic anaemia), livedo reticularis, nephropathy and valvular heart disease have been reported, which suggests that the clinical spectrum of aPL-related manifestations extends beyond that indicated in the classification criteria. Studies have demonstrated that more than 40% of children with aPLs demonstrated non-thrombotic aPL-related clinical manifestations alone. Moreover, our results showed that the pathogenesis of non-criteria manifestations is characterised by “APS vasculopathy”. The present review introduces the characteristics and findings of non-criteria manifestations observed in juvenile APS.

Why thromboembolism occurs in some patients with thrombocytopenia and treatment strategies

Platelets play such an important role in the process of thrombosis that patients with thrombocytopenia generally have an increased risk of bleeding. However, abnormal thrombotic events can sometimes occur in patients with thrombocytopenia, which is unusual and inexplicable. The treatments for thrombocytopenia and thromboembolism are usually contradictory. This review introduces the mechanisms of thromboembolism in patients with different types of thrombocytopenia and outlines treatment recommendations for the prevention and treatment of thrombosis. According to the cause of thrombocytopenia, this article addresses four etiologies, including inherited thrombocytopenia (Myh9-related disease, ANKRD26-associated thrombocytopenia, Glanzmann thrombasthenia, Bernard-Soulier syndrome), thrombotic microangiopathy (thrombotic thrombocytopenic purpura, atypical hemolytic uremic syndrome, hemolytic uremic syndrome, Hemolysis Elevated Liver enzymes and Low Platelets syndrome, disseminated intravascular coagulation), autoimmune-related thrombocytopenia (immune thrombocytopenic purpura, antiphospholipid syndrome, systemic lupus erythematosus), and acquired thrombocytopenia (Infection-induced thrombocytopenia and drug-induced thrombocytopenia, heparin-induced thrombocytopenia). We hope to provide more evidence for clinical applications and future research.

Cryptic conspirators: a conversation about thrombocytopenia and antiphospholipid syndrome

Purpose of review

Although antiphospholipid syndrome (APS) is best known for conveying increased risk of thrombotic events and pregnancy morbidity, thrombocytopenia is also recognized as a common association. In this review, we will explore the relationship between thrombocytopenia and APS, highlighting our evolving understanding – and persistent knowledge gaps – through clinically oriented questions and answers.

Recent findings

A history of thrombocytopenia likely portends a more severe APS phenotype (including increased risk of thrombosis). Although the pathophysiology underlying thrombocytopenia in APS has yet to be definitively revealed, mechanisms that play a role (at least in subsets of patients) include: immune thrombocytopenic purpura/ITP-like autoantibodies against platelet glycoproteins; antiphospholipid antibody (aPL)-mediated platelet activation and consumption; and potentially life threatening thrombotic microangiopathy. Although thrombocytopenia is often ‘mild’ in APS (and therefore, may not require specific therapy), there are causes of acute-onset thrombocytopenia that mandate emergent work-up and treatment. When APS-related thrombocytopenia does require therapy, the approach must be individualized (requiring an understanding of pathophysiology in the particular APS patient). For patients with ITP-like disease, rituximab is emerging as a popular approach to treatment; in contrast, there are hints that thrombopoietin mimetics may be associated with elevated thrombotic risk.

Summary

Thrombocytopenia is common in APS, and is likely associated with more severe disease. Improved understanding of thrombocytopenia in APS has the potential to improve risk stratification, reveal novel aspects of APS pathophysiology, and lead to treatments that are more individualized and holistic.

COVID-19 and Hypercoagulability: A Review

Thrombotic complications of the novel coronavirus (COVID-19) are a concerning aspect of the disease, due to the high incidence in critically ill patients and poor clinical outcomes. COVID-19 predisposes patients to a hypercoagulable state, however, the pathophysiology behind the thrombotic complications seen in this disease is not well understood. Several mechanisms have been proposed and the pathogenesis likely involves a host immune response contributing to vascular endothelial cell injury, inflammation, activation of the coagulation cascade via tissue factor expression, and shutdown of fibrinolysis. Treatments targeting these pathways may need to be considered to improve clinical outcomes and decrease overall mortality due to thrombotic complications. In this review, we will discuss the proposed pathophysiologic mechanisms for thrombotic complications in COVID-19, as well as treatment strategies for these complications based on the current literature available.

Clinical characteristics and risk factors of microvascular involvement in primary antiphospholipid syndrome: a longitudinal single-center study in China

OBJECTIVES

The objective of this study was to investigate risk factors of microvascular involvement and survival in Chinese patients with primary antiphospholipid syndrome.

METHODS

In this single-center, retrospective study, we enrolled 112 patients with a confirmed diagnosis of primary antiphospholipid syndrome who were admitted to Peking Union Medical College Hospital from January 2004 to December 2016. Demographic data, clinical characteristics, laboratory results, and follow-up records were collected.

RESULTS

A total of 112 patients with primary antiphospholipid syndrome were studied. Microvascular involvement was identified in 21 patients (18.75%). Patients with microvascular involvement experienced fewer episodes of arterial or venous thrombosis (28.6% vs. 84.6%) and a higher incidence of thrombocytopenia (85.7% vs. 54.9%), respectively. Low complement and elevated high-sensitivity CRP levels were observed more frequently in the microvascular group compared with the non-microvascular group (complement 38.1% vs. 18.7%; high-sensitivity CRP 71.4% vs. 31.9%, respectively). Anti-β2-glycoprotein I antibodies were more prevalent in patients with microvascular involvement than in patients without (66.7% vs. 33.0%, respectively). Multivariate logistic regression analysis revealed that thrombocytopenia (odds ratio = 4.523, 95% confidence interval 1.139-17.962), elevated high-sensitivity CRP levels (odds ratio = 6.385, 95% confidence interval 1.969-20.704), and anti-β2-glycoprotein I antibody positivity (odds ratio = 5.042, 95% confidence interval 1.555-16.352) were independent risk factors for microvascular involvement. A Kaplan-Meier analysis revealed that survival was significantly poorer in patients with microvascular involvement compared with patients without (p = 0.0278).

CONCLUSIONS

In addition to arterial and venous thrombosis, antiphospholipid syndrome can affect the microvasculature of select organs. It is thus important for clinicians to be aware that antiphospholipid syndrome-associated microvascular involvement has a unique pathogenesis and can be a life-threatening condition.

Anti-RNP/Sm antibodies in patients with systemic lupus erythematosus and its role in thrombosis: a case-control study

OBJECTIVE

To validate the association of thrombotic events with positive lupus anticoagulant (LA) and co-presence of anti-RNP/Sm, as well as the diagnostic accuracy of this combination of antibodies for thrombosis.

METHODS

Case-control study of patients with systemic lupus erythematosus (SLE) who presented thrombosis after SLE diagnosis and controls with SLE without thrombosis. Comorbidities, traditional risk factors, clinical variables, and treatment were evaluated. Antiphospholipid (aPL) and anti-RNP/Sm antibodies were determined.

RESULTS

Sixty-three cases and 63 controls were studied, 88% women, median age of 40 years, and disease duration of 135 months at study inclusion. No differences were found between groups regarding age, comorbidities, or clinical characteristics at SLE diagnosis. Patients with thrombosis were more frequently positive for anti-RNP/Sm (p = 0.001), IgG aCL (p = 0.02), IgG anti-B2GPI (p = 0.02), IgM anti-B2GPI (p = 0.02), LA (p < 0.001), the combination of anti-RNP/Sm + LA (p < 0.001), and aPL triple marker (p = 0.002), compared to controls. The combination of anti-RNP/Sm + LA, SLEDAI-2 K, and prednisone dose was associated with thrombosis (p < 0.05). The combination of anti-RNP/Sm + LA showed 56% sensitivity, 79% specificity, 73% positive predictive value, 64% negative predictive value, positive likelihood ratio (LR) 2.69, and negative LR 0.56 for predicting thrombosis. No difference was found in the comparison of area under the curve between LA alone and the combination of anti-RNP/Sm + LA (p = 0.73).

CONCLUSION

Thrombosis was associated with disease activity, dose of prednisone, and the combination of anti-RNP/Sm antibodies and LA. This combination of antibodies could be useful in the identification of SLE patients at risk of thrombosis.

Arterial/venous thrombosis, fetal loss and stillbirth in pregnant women with systemic lupus erythematosus versus primary and secondary antiphospholipid syndrome: a systematic review and meta-analysis

BACKGROUND

We aimed to systematically compare arterial/venous thrombosis, fetal loss and stillbirth in pregnant women with systemic lupus erythematosus (SLE), primary anti-phospholipid syndrome (PAPS) and secondary anti-phospholipid syndrome (SAPS).

METHODS

Online databases were carefully searched for relevant publications comparing SLE with PAPS and/or SAPS in pregnancy. Studies were included if: they compared SLE with APS [SLE versus PAPS or SLE versus SAPS or SLE versus PAPS and SAPS respectively] in pregnant women; and they reported specific adverse outcomes as their clinical endpoints including arterial/venous thrombosis, fetal loss and stillbirth. Risk ratios (RR) with 95% confidence intervals (CIs) were used as statistical parameters and the analysis was carried out by the RevMan 5.3 software.

RESULTS

A total number of 941 pregnant women were included: 556 were candidates of SLE; 200 were candidates of PAPS; and 185 were candidates of SAPS. APS was associated with a significantly higher risk of fetal loss (RR: 4.49, 95% CI: 2.09-9.64; P = 0.0001). In addition, stillbirth and arterial/venous thrombosis were also significantly increased with APS (RR: 6.65, 95% CI: 2.14-20.60; P = 0.001) and (RR: 3.95, 95% CI: 1.28-12.16; P = 0.02) respectively. When patients with PAPS were compared with patients who suffered from SLE alone, fetal loss and arterial/venous thrombosis were still significantly higher with the former. When SAPS were compared with SLE (without anti-phospholipid antibodies), arterial/venous thrombosis, stillbirth and fetal loss were still significantly higher with SAPS. However, no significant difference was observed in arterial/venous thrombosis and fetal loss between PAPS and SAPS.

CONCLUSIONS

PAPS and SAPS were associated with significantly higher arterial/venous thrombosis, fetal loss and stillbirth in comparison to SLE. However, no significant difference was observed when PAPS was compared to SAPS.

Platelets activated by the anti-β2GPI/β2GPI complex release microRNAs to inhibit migration and tube formation of human umbilical vein endothelial cells

Background

Patients with anti-β2GPI antibodies display significantly higher platelet activation/aggregation and vascular endothelial cell damage. The mechanism underlying the correlation between platelet activation, vascular endothelial cell dysfunctions and anti-β2GPI antibodies remains unknown.

Methods

In this study, we derived miR-96 and -26a from platelets activated by the anti-β2GPI/β2GPI complex and explored their role in modulating human umbilical vein endothelial cell (HUVEC) migration and tube formation.

Results

Anti-β2GPI/β2GPI complex induces the release of platelet-derived microparticles (p-MPs). The amounts of miR-96 and -26a in these p-MPs were also higher than for the control group. Co-incubation of HUVECs with p-MPs resulted in the transfer of miR-96 and -26a into HUVECs, where they inhibited migration and tube formation. The targeting role of these miRNAs was further validated by directly downregulating targeted selectin-P (SELP) and platelet-derived growth factor receptor alpha (PDGFRA) via luciferase activity assay.

Conclusion

Our study suggests that miR-96 and -26a in p-MPs can inhibit HUVEC behavior by targeting SELP and PDGFRA.

The role of platelets in antiphospholipid syndrome

Despite extensive research, the pathogenesis of antiphospholipid syndrome (APS) remains obscure in many aspects. However, it is widely accepted that thrombosis is the result of a hypercoagulable state caused by antibodies directed against β2-glycoprotein I (β2-GPI), a protein whose physiological role is unknown. Although underestimated, platelets may be involved in APS and its thrombotic manifestations, especially arterial, in several ways. Thrombocytopenia is the most relevant non-criteria manifestation of APS, possibly caused by direct binding of anti-β2-GPI antibodies or anti-β2-GPI-β2-GPI complexes. On the other hand, platelets may have a key role in APS-related thrombosis due to the presence of multiple receptors that can interact with anti-β2-GPI antibodies (especially apolipoprotein E receptor 2' (apoER2') and glycoprotein Ibα (GPIbα)) with consequent release of different procoagulant mediators such as thromboxane B2, platelet factor 4 (PF4), and platelet factor 4 variant (CXCL4L1). The aim of this review is to put together evidence on the possible role of platelets in APS and to stimulate further research on the issue.

Antiphospholipid Antibodies and Procoagulant Profile in Tunisians With Inflammatory Bowel Diseases

The hypercoagulable state accompanying inflammatory bowel diseases (IBDs) is still poorly understood. The aim of this study was to assess antiphospholipid antibodies (APAs) and a large panel of inherited and acquired thrombotic markers simultaneously in a sample of Tunisian patients with IBD. In total, 89 consecutive patients with IBD (mean age 38 ± 15 years; 48 with Crohn disease and 41 with ulcerative colitis) and 129 controls were prospectively evaluated for immunoglobulin (Ig) G, IgM, and IgA antibodies against cardiolipin (aCL), β2glycoprotein I (aβ2GPI), and prothrombin (aPT); IgG and IgM antibodies against phosphatidic acid (aPA), phosphatidylinositol (aPI), and annexin V (aAnnV); lupus anticoagulant (LA); coagulation factors; natural inhibitors; and thrombotic genetic polymorphisms. Levels of fibrinogen, factors II, V, and VIII and von Willebrand factor, antithrombin, and protein C were significantly higher in patients with IBD than in controls (P < .05 for all comparisons). At least 1 APA subset was detected in 54 patients. The frequencies of antibodies against anionic phospholipids-aCL, aPI, and aPA-in patients with IBD were 15.9%, 21.3%, and 14.6%, respectively. The frequencies of antiphospholipid cofactor antibodies were 39.8% for aβ2GPI and 15.7% for both aAnnV and aPT. Isolated aβ2GPI IgA was detected in 22 patients, and 12 (13.5%) patients had LA. The IgA aβ2GPI antibodies were frequently detected in Tunisian patients with IBD. These results are of potential diagnostic, prognostic, and therapeutic interest.

Platelet and endothelial activation in catastrophic and quiescent antiphospholipid syndrome

Antiphospholipid antibodies (aPL) seem to induce a prothrombotic state by activating endothelium and platelets, but no studies have evaluated systematically the effects of aPL from patients with the antiphospholipid syndrome (APS) in quiescent versus catastrophic phase. Our aims were to evaluate the in vitro effects on platelet activation of anti-β2 glycoprotein I (anti-β2GPI) antibodiesisolated from APS patientin either quiescent or catastrophic phase and to investigate ex vivo platelet and endothelial activation in patients with quiescent or catastrophic APS. Anti-β2GPI antibodies were isolated from plasma of a pregnant woman in two different stages of APS (quiescent and catastrophic, respectively). They were co-incubated with washed platelets from healthy controls that were then challenged with TRAP-6 (thrombin receptor activating peptide 6) and the expression of P- selectin (P-sel) on platelets was assessed by flow cytometry. Moreover, plasma samples from six patients with quiescent, four with catastrophic APS and 10 controls were assessed for several markers of platelet and endothelial activation. The results showed that purified anti-β2GPI antibodies co-incubated with platelets enhanced TRAP-6- induced platelet P-sel expression. Notably, anti-β2GPI antibodies isolated during the catastrophic phase enhanced platelet P-sel expression more than antibodies isolated from the same patient in the quiescent stage of disease. Moreover, APS patients had significantly higher plasma levels of soluble (s) Psel, sCD40 ligand, soluble vascular cell adhesion molecule 1 and monocyte chemoattractant protein 1 than control subjects. In addition, sP-sel and von Willebrand factor activity were significantly higher during catastrophic than in quiescent phase.

Treatment, survival, and thromboembolic outcomes of thrombotic storm in children

OBJECTIVE

To describe the course and management of thrombotic storm in 8 children.

STUDY DESIGN

Clinical data were collected and analyzed for consecutive children diagnosed with thrombotic storm, aged 6 months to 21 years inclusive, in the context of a single-institution prospective inception cohort study. Thrombotic storm was defined as newly diagnosed multisite venous thromboembolism (VTE) with acute thrombus progression despite conventional or higher than conventional dosing of heparin or low molecular weight heparin. All evaluations and therapies were ordered by the treating physicians in the context of clinical decision making.

RESULTS

Eight of the 178 children with VTE enrolled in the cohort between March 2006 and November 2009 were diagnosed with thrombotic storm. Antiphospholipid antibodies were acutely positive in 6 children, of whom heparin-induced thrombocytopenia was confirmed by serotonin release assay in 2 and atypical in 1. One child died. Five children received a direct thrombin inhibitor, titrated to achieve normalization of markedly elevated D-dimer levels. All children were transitioned to fondaparinux or enoxaparin before receiving extended anticoagulation with warfarin. Immunomodulatory therapy was instituted in all children. During follow-up (median duration, 3 years; range, 2-6 years), 3 of the 7 surviving children experienced recurrent VTE, and 4 children had clinically significant postthrombotic syndrome.

CONCLUSION

Thrombotic storm is an infrequent but potentially fatal presentation of VTE in children. Administration of direct thrombin inhibitors and immune modulation can achieve quiescence, although long-term adverse outcomes are common.

Extensive skin necrosis induced by low-molecular-weight heparin in a patient with systemic lupus erythematosus and antiphospholipid syndrome

Low-molecular-weight heparin-induced skin necrosis can occur as a clinical feature of heparin-induced thrombocytopenia syndrome. Heparin-induced thrombocytopenia and antiphospholipid syndromes have some clinical features in common, including thrombocytopenia and thrombotic events. We describe a 46-year-old woman who developed extensive necrosis in the breast and other sites secondary to the use of enoxaparin after an elective hysterectomy. During the postoperative period, diagnoses of systemic lupus erythematosus and antiphospholipid syndrome were made because of some clinical and laboratory features (seizure, nephritis, bicytopenia, positive nuclear antibody, and positive antiphospholipid antibodies with a previous thrombotic event). The patient's clinical course improved only after corticosteroid therapy and the suspension of enoxaparin. Heparin-induced thrombocytopenia and antiphospholipid syndromes can have platelet factor 4 as a common denominator in their pathogenesis because platelet factor 4 tetramers can bind β2-glycoprotein molecules. This case suggests that use of low-molecular-weight heparins could be more risky in patients with an underlying immune disease and/or could trigger immune reactions that must be analyzed in larger studies.

Sjogren's syndrome: an update on clinical, basic and diagnostic therapeutic aspects

The 11th International Symposium for Sjogren's syndrome was held in Athens, Greece in September 2011. This symposia is part of a long series of meetings that have attempted to meet the needs of both scientists and physicians in improving the healthcare of their patients with Sjogren's syndrome. Sjogren's syndrome affects almost 0.5% of the general population and is second only to rheumatoid arthritis amongst the systemic autoimmune diseases. More importantly, it has daily implications for the millions of sufferers around the world. The goal of this meeting, which included nearly 200 abstracts and invited lectures, was to address the critical needs in the clinical practice of Sjogren's syndrome. This volume is a composite of select papers that were presented at this meeting and attempts to provide a critical overview of clinical and basic science. The volume includes a variety of themes and, importantly, raises issues that are still unresolved but which are important in our future diagnostic and therapeutic efforts.

Transient Global Amnesia as the First Symptom of Primary Antiphospholipid Syndrome: A Case Report

We describe the case of a 45-year-old woman who had drawn our attention for some recent episodes of transient global amnesia that, upon further examination, resulted from ischemic events caused by multiple arterial thrombosis (bilateral internal carotid occlusion, significant stenosis of the right external carotid, mild stenosis of the right vertebral artery, right anterior cerebral artery occlusion and severe stenosis of the anterior descending coronary artery) due to primary antiphospholipid syndrome. Revascularisation of either carotid was not attempted. A percutaneous intervention in the anterior descending coronary artery stenosis was performed successfully. Due to severe arterial thrombosis, the patient was discharged with only duplex antiplatelet treatment and subcutaneous anticoagulant therapy, since immunotherapy is not indicated in primary APS. The occurrence of transient global amnesia should raise the suspicion of APS.

Nephrotic and anti-phospholipid syndromes: multisystem conditions associated with acute myocardial infarction in young patients

Acute myocardial infarction is relatively uncommon in patients under the age of 40 years. Unlike the older patients where rupture of coronary artery atherosclerotic plaque is the main underlying pathology, the pathogenesis in younger patients can be varied and may require different diagnostic and therapeutic approaches. Hypercoagulable state associated with nephrotic syndrome and antiphospholipid syndrome can lead to the development of occlusive coronary artery thrombus in absence of atherosclerotic coronary artery disease. Acute myocardial infarction in such a setting can sometimes be the first manifestation of an underlying disease. We describe a case of myocardial infarction in a young man with both nephrotic and antiphospho-lipid syndromes and present a brief literature review.

Pathogenesis of systemic lupus erythematosus revisited 2011: end organ resistance to damage, autoantibody initiation and diversification, and HLA-DR

Systemic lupus erythematosus (SLE) is a multi-system disorder resulting from interaction of susceptibility genes and environmental factors. SLE has protean clinical presentations at the initial diagnosis and relapses. SLE-related autoantibodies have unique patterns of diversification to linked proteins such as the snRNP particle and the diversification takes years before clinical diagnosis. There are both clinical and experimental evidence to indicate that separate genes contribute to autoimmunity and end organ damage and these genes are independent and interactive. Among the numerous susceptibility genes, HLA-D complex is dominant. Results from the authors' laboratories led us to postulate a unified hypothesis for SLE pathogenesis. This hypothesis states that SLE-autoantibodies are initiated by environmental T cell epitope mimics of the SLE-related autoantigens in hosts with susceptible HLA-D alleles. These autoantibodies diversify over a period of years due the accumulation of cross-reactive T cells. This process ultimately leads to the generation of organ specific autoantibodies and autoreactive effector T cells due to the polyreactive nature of T and B cell receptors from hosts with susceptibility genes to end organ damage, resulting in protean clinical presentations. This hypothesis accounts for most of the features unique to SLE and has clinical implications as to how patients should be treated.

Autoimmunity in 2010

There is now growing evidence that autoimmunity is the common trait connecting multiple clinical phenotypes albeit differences in tissue specificity, pathogenetic mechanisms, and therapeutic approaches cannot be overlooked. Over the past years we witnessed a constant growth of the number of publications related to autoimmune diseases in peer-reviewed journals of the immunology area. Original data referred to factors from common injury pathways (i.e. T helper 17 cells, serum autoantibodies, or vitamin D) and specific diseases such as multiple sclerosis, systemic lupus erythematosus, and rheumatoid arthritis. As an example, the issue of a latitudinal gradient in the prevalence and incidence rates has been proposed for all autoimmune diseases and was recently coined as geoepidemiology to suggest new environmental triggers for tolerance breakdown. The present article is aimed at reviewing the articles that were published over the past year in the major autoimmunity and immunology journals.

Chella David: a lifetime contribution in translational immunology

Immunology, like most scientific disciplines, is filled with buzz words. One such buzz word or term has been coined "translational immunology". Indeed, translational research is amongst the most popular expressions used to justify the use of basic research in the hopes that such research will lead to solutions to clinical problems. In fact, no such justification is needed and some of the most important observations in clinical medicine have been derived from basic science; basic science that had no idea at its time of its usefulness in clinical medicine. This special issue is devoted to Chella David. Chella's contributions in immunology have been legion. Before inbred mice became popular, long before multi-million dollar companies were developed to develop such models, Chella David was hard at the bench studying the genetics of the murine immune system and the importance of such mouse models in autoimmune diseases. Importantly, Dr. David provided animals without strings, without the burdens of MTAs, that now impede research. Chella has been generous with his time, with his reagents, and has been a caring and devoted mentor to generations of students. This issue is part of our series to recognize autoimmunologists and dedicated themes that include papers in multiple disciplines of immunology, but especially are focused on cutting-edge applications that will improve clinical therapeutics. Chella David, at age 75, is an athlete in immunology and still keeps going with the same enthusiasm as manifest as a young post-doc.