Inflammatory response and the endothelium

Updates on Anticancer Therapy-Mediated Vascular Toxicity and New Horizons in Therapeutic Strategies

Vascular toxicity is a frequent adverse effect of current anticancer chemotherapies and often results from endothelial dysfunction. Vascular endothelial growth factor inhibitors (VEGFi), anthracyclines, plant alkaloids, alkylating agents, antimetabolites, and radiation therapy evoke vascular toxicity. These anticancer treatments not only affect tumor vascularization in a beneficial manner, they also damage ECs in the heart. Cardiac ECs have a vital role in cardiovascular functions including hemostasis, inflammatory and coagulation responses, vasculogenesis, and angiogenesis. EC damage can be resulted from capturing angiogenic factors, inhibiting EC proliferation, survival and signal transduction, or altering vascular tone. EC dysfunction accounts for the pathogenesis of myocardial infarction, atherothrombosis, microangiopathies, and hypertension. In this review, we provide a comprehensive overview of the effects of chemotherapeutic agents on vascular toxicity leading to hypertension, microvascular rarefaction thrombosis and atherosclerosis, and affecting drug delivery. We also describe the potential therapeutic approaches such as vascular endothelial growth factor (VEGF)-B and prokineticin receptor-1 agonists to maintain endothelial function during or following treatments with chemotherapeutic agents, without affecting anti-tumor effectiveness.

Antiphospholipid antibodies and anticoagulant therapy: capillaroscopic findings

Background

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by specific vascular and obstetric manifestations and by antiphospholipid antibodies (aPL) positivity. Microvascular damage in the course of APS and “aPL carrier” patients without symptoms is poorly investigated.

Objectives

This study aims to compare nailfold videocapillaroscopy (NVC) microvascular parameters in APS patients and non-symptomatic "aPL carriers" and to investigate their possible correlations with different aPL subtypes.

Methods

NVC was performed during standard evaluations in 18 APS patients (mean age 50 ± 13.8 years), 24 "aPL carriers" without symptoms (mean age 46.4 ± 16.4 years), and 18 control patients (CTR) (mean age 74 ± 12.5 years) taking oral anticoagulants for non-immunological indications (i.e., cardiovascular accidents). All patients were investigated for the presence of dilated capillaries, giant capillaries, microhemorrhages, capillary loss, and further non-specific/specific abnormalities (i.e., branched “bushy” capillaries, sign of neoangiogenesis) by NVC. Every alteration was also classified according to a semi-quantitative score. Lupus anticoagulant, anticardiolipin antibodies, and antibeta2 glycoprotein I antibodies were tested in each patient.

Results

APS patients showed at NVC increased frequency of microhemorrhages (p = 0.039)—particularly a “comb-like” pattern (parallel hemorrhages) (p = 0.002)—than "aPL carriers". Of note, there were no significant differences concerning the isolated number of microhemorrhages between APS and the CTR group (p = 0.314), but “comb-like” hemorrhages were significantly more frequent in the APS group (p = 0.034). Not any significant correlation was found between the aPL subtypes and NVC parameters.

Conclusions

APS patients showed significantly a greater number of non-specific NVC abnormalities than "aPL carriers", particularly the “comb-like” NVC pattern. Oral anticoagulants may represent a confounding factor for isolated microhemorrhages. Not any correlation was found between aPL subtypes and NVC parameters. Further investigations are needed to better characterize the microvascular endothelium damage induced by aPL.

Arterial thrombosis in antiphospholipid syndrome (APS): Clinical approach and treatment. A systematic review

Thrombotic Antiphospholipid Syndrome (APS) is a condition affecting young individuals in whom a thromboembolic event occurs in the presence of circulating antiphospholipid antibodies (aPL). An extensive body of literature has covered the most common clinical presentation of the syndrome, venous thromboembolism. Arterial thrombosis in APS, a lesser clinical expression, is less studied. This review will concentrate on the body of literature concerning pathogenesis, clinical presentation and management of arterial thrombosis in APS.

Prediction of preeclampsia using combination of biomarkers at 18-23 weeks of gestation: A nested case-control study

OBJECTIVE

To evaluate the combination of plasma activated endothelial microparticles (CD62e), serum Copeptin (CPP) and placental growth factor (PlGF) levels at 18-23 weeks of gestation for prediction of preeclampsia (PE) in primigravid women.

METHODS

This was a nested case-control study from a prospective cohort of 1115 primigravid women attending antenatal care clinic. Plasma levels of CD62e and serum Copeptin, PlGF levels were measured by flow cytometry and ELISA, respectively. Data were presented as median (Interquartile range) and biomarker levels were compared between patients and controls using Mann-Whitney Test. Using binary logistic regression, predictive potential of a combination of biomarkers for PE prediction was determined.

RESULTS

Women who developed PE 41 (3.97%) showed significantly increased levels of plasma CD62e [799.33 (546.86-1249.29) versus 384.08 (245.03-576.00), p < 0.0001], serum Copeptin [303.42 (226.01-484.18) versus 207.24 (169.73-276.46), p < 0.0001] and reduced level of PlGF [238.38 (161.36-312.62) versus 947.21 (466.7-1428.56), p < 0.0001] compared to controls at 18-23 weeks of gestation. None of the marker showed statistically significant alteration in levels in fetal growth restriction (FGR) group 68 (6.58%) compared to controls. Using binary logistic regression analysis, AUC, Sensitivity, specificity, PLR, NLR, PPV, and NPV of combination of CD62e, Copeptin and PlGF for prediction of PE at 18-23 weeks of gestation was 0.969, 92.3%, 90.3%, 9.73, 0.08, 79.17%, and 96.94%, respectively.

CONCLUSION

At 18-23 weeks, Combination of CD62e microparticles, copeptin, and PlGF levels can effectively identify women at risk of developing PE later in gestation.

Subclinical atherosclerosis in asymptomatic carriers of persistent antiphospholipid antibodies positivity: A cross-sectional study

BACKGROUND

Whereas the relationship between subclinical atherosclerosis and antiphospholipid syndrome (APS) has been widely investigated, little is known about subclinical atherosclerosis in asymptomatic carriers with isolated antiphospholipid antibodies positivity (APP).

METHODS

Consecutive APP carriers, APS subjects and matched controls were enrolled. Intima-media thickness of the common carotid artery (CCA-IMT) and of the Bulb (Bulb-IMT) and the prevalence of carotid plaques were assessed in all enrolled subjects.

RESULTS

A total of 104 APP carriers, 221 APS subjects, and 325 matched controls were recruited. As compared with controls, APP carriers and APS subjects showed a higher CCA-IMT (0.90 ± 0.24 vs 0.82 ± 0.12, p = 0.014 and 0.93 ± 0.42 vs 0.82 ± 0.12, p < 0.001, respectively), Bulb-IMT (1.10 ± 0.44 vs 0.95 ± 0.18, p = 0.006 and 1.22 ± 0.68 vs 0.95 ± 0.18, p < 0.001, respectively) and an increased prevalence of carotid plaques (33.7% vs 10.2%, p < 0.001 and 38.5% vs 10.2%, p < 0.001, respectively). These results were confirmed stratifying for antibody isotype, after excluding subjects with systemic lupus erythematosus or other autoimmune diseases and after adjusting for major clinical and demographic variables. CCA-IMT, Bulb-IMT and the prevalence of carotid plaques were higher in subjects with high-titer antibodies and progressively increased for an increasing number of positive antibodies.

CONCLUSIONS

Similar to APS subjects, APP carriers have enhanced subclinical atherosclerosis, a more severe disease being observed in the presence of high-titer antibodies and multiple antibodies positivity. These data argue for a strict monitoring of subclinical signs of atherosclerosis and of cardiovascular risk factors in asymptomatic APP carriers.

Antiphospholipid Antibodies and Acute-Phase Response in Non-Metastatic Colorectal Cancer Patients

Aim

To investigate the plasma levels and prevalence of the most common antiphospholipid antibodies, as well as their relationships with several plasma markers of inflammation, in order to characterize some aspects of cancer thrombophilia.

Materials and methods

Eighty-three cancer patients with non-metastatic colorectal solid tumors and 94 control subjects were tested for the presence of IgG/IgM/IgA anti-cardiolipin and anti-β2-glycoprotein I antibodies and of several acute-phase reactants, i.e., fibrinogen, factor VIII:C and C4b-binding protein.

Results

In cancer patients the plasma levels of the acute-phase reactants and the IgA/IgG anti-cardiolipin and IgA anti-β2-glycoprotein I antibodies were significantly higher; the acute-phase reactants were significantly correlated with anti-cardiolipin antibodies; the prevalence of antiphospholipid antibodies was not significantly higher.

Conclusions

In patients with non-metastatic colorectal cancer the acute-phase response is associated with antiphospholipid generation. This could represent a further pathogenetic mechanism for the short-term post-surgery thrombotic complications of patients with colorectal cancer.

The Differences Between Childhood and Adult Onset Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is a rare autoimmune disease of unknown etiology that represents a leading cause of acquired thromboembolism and recurrent miscarriage. It is characterized by the persistent elevated presence of pathogenic antiphospholipid auto-antibodies directed against cardiolipin, ß2-glycoprotein-I, and/or a positive lupus anticoagulant test. As with many autoimmune disorders, the pathogenesis of APS is believed to be the result of a complex interaction between environmental triggers and genetic predisposition. Although more common in adults, APS occasionally manifests in the neonatal period and throughout childhood. Adut-onset APS classification criteria are poorly validated to the pediatric population (in which pregnancy related complications are seldom seen) and as a result, assessment of the prevalence of the disease in childhood is difficult. Thromboembolic events seen in children include deep venous thrombosis in addition to stroke and pulmonary embolism, which can lead to significant long-term disability. The disease can be classified as either primary (when occurring in isolation) or secondary, in which the disease is diagnosed in the context of another underlying disease, most commonly systemic lupus erythematosus. A variety of laboratory and clinical difference are seen between pediatric and adult-onset APS. The marked female predominance seen in adult-onset disease is less evident in childhood where the gender split is more evenly spread. In addition, children with APS are at a higher risk of recurrent thromboembolism than adults. The treatment of childhood-onset APS is challenging due to a lack of large-scale prospective studies in the pediatric population. Therapeutic options are often based upon treatment guidelines that have been based upon literature from the adult-onset form of the disease. In the majority of cases, treatment is focused on the prevention of further thrombosis through treatment with long-term anti-coagulation therapy. The evidence for the use of antiplatelet agents (such as aspirin) and hydroxychloroquine is inconclusive. It is important to remember that anti-coagulation can have significant lifestyle implications for the child with APS and it is essential to consider potential implications relating to school and recreational activities, with contact sports often discouraged due to the increased risk of bleeding.

Serum of patients with antiphospholipid syndrome induces adhesion molecules in endothelial cells

OBJECTIVE

The antiphospholipid syndrome (APS) is a systemic auto-immune disease with an unclear pathophysiology. The aim of our study was to understand the development of APS on a cellular level. Therefore, we analyzed the influence of human serum of APS patients on endothelial expression of specific genes and proteins in comparison to a control group.

METHODS

In this study, we analyzed the expression of ICAM-1, VCAM-1, E-selectin and annexin V in primary cultures of human umbilical vein endothelial cells (HUVEC) in response to 10% (v/v) serum of control patients (n = 6), patients with systemic lupus erythematosus (SLE) and no APS (n = 4) or APS patients (n = 9) for 24 h. Total RNA was prepared from confluent endothelial cell layers and mRNA expression of ICAM-1, VCAM-1 and E-selectin was analyzed by reverse transcription polymerase-chain reaction (RT-PCR). The protein expression was determined by Western blot. Serum protein concentrations of soluble forms of adhesion molecules sICAM-1 and sVCAM-1 were quantified by ELISA. Gene expression data were correlated with clinical parameters.

RESULTS

The mRNA expression of ICAM-1 was increased in cells incubated with serum from APS patients (166 ± 22% of control; P = 0.023). Serum of patients with (SLE)/no APS caused a 1.4-fold higher ICAM-1 mRNA level. Western blot analysis showed an increase in protein expression of adhesion molecules ICAM-1 (260 ± 49%; P = 0.011) and VCAM-1 (357 ± 97%; P = 0.023) in cells that were incubated with serum from APS patients. Plasma analysis showed elevated levels of sVCAM-1 in APS patients (189 ± 34%; P = 0.045) compared to the levels measured in the control group. The sVCAM-1 plasma level was correlating with the frequency of abortions.

CONCLUSION

An augmented expression of endothelial adhesion molecules is involved in the pathophysiology of patients with antiphospholipid syndrome.

Antiphospholipid (Hughes) syndrome and atheroma

The antiphospholipid syndrome (APS) is a prothrombotic disorder characterised by recurrent thrombotic events and pregnancy morbidity in the context of autoantibodies against phospholipid binding proteins. There is increasing evidence that these autoantibodies are associated with accelerated atherosclerosis. The presence of stenotic lesions radiologically and abnormalities of the ankle-brachial index, flow-mediated dilatation and carotid abnormalities supports this view and this clinical evidence is reviewed.

Inflammation and the pathogenesis of atherosclerosis in systemic lupus erythematosus

Atherosclerosis is a complicated inflammatory process characterized by the interactions of numerous different moieties including lipids, enzymes, endothelial cells, cytokines, chemokines, leukocytes, adhesion molecules, complement and antibodies. As in the pathogenesis of many lupus disease processes, the increased risk of atherosclerosis seen in systemic lupus erythematosus (SLE) is likely due to the complex interplay of many of these inflammatory mediators. Expanding our understanding of the pathogenesis of atherosclerosis in SLE is critical if we are to improve the quality of care and reduce mortality in this vulnerable population.

The antiphospholipid syndrome in patients with systemic lupus erythematosus

The antiphospholipid syndrome (APS) is an autoimmune disease characterized by the occurrence of venous and/or arterial thrombosis and pregnancy morbidity in the presence of pathogenic autoantibodies known as antiphospholipid antibodies (aPL). APS may be associated with other diseases, mainly systemic lupus erythematosus (SLE). The presence or absence of SLE might modify the clinical or serological expression of APS. Apart from the classical manifestations, APS patients with associated SLE more frequently display a clinical profile with arthralgias, arthritis, autoimmune hemolytic anemia, livedo reticularis, epilepsy, glomerular thrombosis, and myocardial infarction. The management of patients with SLE and APS/aPL should include an accurate stratification of vascular risk factors. Low dose aspirin and hydroxychloroquine should be considered as primary prophylaxis. In high risk situations, such as surgery, prolonged immobilization, and puerperium, the prophylaxis should be potentiated with low molecular weight heparin. The challenge of treating patients with a previous vascular event (secondary prophylaxis) is the choice of treatment (anti-platelet agents, anticoagulation with vitamin K antagonists or combined therapy) and its duration, based on individual risk stratification and the site of vascular presentation. The role of novel anticoagulants in APS patients is still to be clearly defined. Novel approaches are needed since the prognosis of SLE patients with APS/aPL is still worse than that of SLE patients with negative aPL. The goal for the future is to improve the outcome of these patients by means of early recognition and optimal preventative treatment.

Cardiac involvement in the antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a systemic autoimmune disease, associated with a hypercoagulable state and fetal loss and with other clinical manifestations including cardiac involvement. Cardiac manifestations of APS are valve abnormalities (valve thickening and vegetations), occlusive arterial disease (atherosclerosis and myocardial infarction), intracardiac emboli, ventricular dysfunction, and pulmonary hypertension. Antiphospholipid antibodies (aPLs) may have a role in the accelerated atherosclerotic arterial disease observed in APS, related to their ability to induce endothelial activation. aPLs have been incriminated in the pathogenesis of heart valve lesions in APS patients. Markers of endothelial cell activation are up-regulated with prominent deposition of aPL in heart valves, suggesting aPL deposition initiates an inflammatory process that recruits complement leading to the valve lesion. Autoantibody-mediated endothelial cell activation probably plays a role in sustaining a proadhesive, proinflammatory, and procoagulant phenotype. The heterogeneity of APS clinical manifestations is likely linked to the varied effects that aPL can induce on endothelial cells and to the different functions that endothelial cells display depending on the anatomic localization.

Impaired endothelial function and increased carotid intima-media thickness in association with elevated von Willebrand antigen level in primary antiphospholipid syndrome

Primary antiphospholipid syndrome (APS) is characterized by venous or arterial thrombotic events and/or recurrent abortions, fetal death, preeclasmpsia, eclampsia in the presence of anticardiolipin antibodies or lupus anticoagulant, in the absence of accompanying diseases. Antiphospholipid antibodies can activate endothelial cells, and were recently implicated in atherosclerosis. To assess potential endothelial impairment and early signs of atherosclerosis, flow-mediated (endothelium-dependent) and nitrate-mediated (endothelium independent) vasodilation, as well as von Willebrand factor antigen level and carotid artery intima-media thickness (IMT) were measured in patients with primary antiphospholipid syndrome and in healthy controls. Flow-mediated vasodilation in patients with primary APS was significantly lower than that of controls (3.43 ± 2.86% versus 7.96 ± 3.57%; P < 0.0001). We also found significantly higher von Willebrand antigen levels in patients with primary APS than in the control group (157.91 ± 52.45% versus 125.87 ± 32.8%; P = 0.012). Moreover, carotid artery IMT was significantly larger in the primary APS group compared to controls (0.714 ± 0.2 mm versus 0.58 ± 0.085 mm; P = 0.0037). Our results reflect ongoing endothelial damage and accelerated atherosclerosis in patients with primary APS, and suggest that vasoprotective therapy may be beneficial in the treatment of these patients. Lupus (2007) 16, 497—503.

Pentraxin 3 as a biomarker of local inflammatory response to vascular injury in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disorder with organ injury related to vasculitis. Inflammation of blood vessels results from auto-immunological activation of endothelial cells. The pentraxin 3 (PTX3), might act as an indicator of vasculitides in many diseases. The aim of this study was to determine whether PTX3 might be useful as a marker of vascular injury in SLE. This study was carried out in a group of 56 SLE women, and in the 28 female volunteers control group. All participants' plasma and serum samples were collected to estimate concentrations (ELISA) of PTX3, soluble thrombomodulin, soluble E-selectin (sE-selectin), soluble P-selectin (sP-selectin), soluble form of vascular cell adhesion molecule 1 (sVCAM-1), soluble inter-cellular adhesion molecule-1 (sICAM-1), soluble platelet endothelial cell adhesion molecule 1, monocyte chemotactic protein-1 (MCP-1) and von Willebrand factor (vWF) activity. Anthropometric, demographic and lifestyle characteristics of SLE patients were also performed. The SLE patients had higher PTX3, vWF, MCP-1, sE-selectin and sVCAM-1 levels than the controls (1.82 ± 1.56 ng/mL, 237 ± 101%, 70.05 ± 18.31 ng/mL, 111.16 ± 49.15 ng/mL and 978.78 ± 462.35 ng/mL vs. 0.86 ± 0.40 ng/mL, 138 ± 43%, 58.56 ± 13.91 ng/mL, 66.04 ± 27.18 ng/mL and 499.07 ± 125.67 ng/mL, respectively). The independent factors affecting PTX3 expression included Systemic Lupus Erythematosus Disease Activity Index, prednisone dose and anemia severity. Moreover, the PTX3 areas under the curve-receiver operating characteristics curves 0.717 ± 0.056 with cut-off level of 1.96 ng/mL was comparable to vWF, MCP-1, sE-selectin, sP-selectin and sICAM-1. PTX3 and sVCAM-1 were the only factors related to SLE activity. Other vascular injury indicators associated with PTX3 were vWF and sVCAM-1. In conclusion, PTX3 concentrations in SLE patients might serve as a indicator of the activation/dysfunction of vascular endothelium.

Antiphospholipid antibodies attenuate endothelial repair and promote neointima formation in mice

Background

Antiphospholipid syndrome patients have antiphospholipid antibodies (aPLs) that promote thrombosis, and they have increased cardiovascular disease risk. Although the basis for the thrombosis has been well delineated, it is not known why antiphospholipid syndrome patients also have an increased prevalence of nonthrombotic vascular occlusion. The aims of this work were to determine if aPLs directly promote medial hypertrophy or neointima formation in mice and to identify the underlying mechanisms.

Methods and Results

Medial hypertrophy and neointima formation invoked by carotid artery endothelial denudation were evaluated in mice administered normal human IgG or aPLs. While aPLs had no effect on medial hypertrophy, they caused exaggerated neointima development. This was related to an aPL‐induced impairment in reendothelialization post denudation, and scratch assays in cell culture revealed that there are direct effects of aPLs on endothelium that retard cell migration. Further experiments showed that aPL antagonism of endothelial migration and repair is mediated by antibody recognition of β2‐glycoprotein I, apolipoprotein E receptor 2, and a decline in bioavailable NO. Consistent with these mechanisms, the adverse impacts of aPLs on reendothelialization and neointima formation were fully prevented by the NO donor molsidomine.

Conclusions

APLs blunt endothelial repair, and there is related aPL‐induced exaggeration in neointima formation after endothelial injury in mice. The initiating process entails NO deficiency mediated by β2‐glycoprotein I recognition by aPLs and apolipoprotein E receptor 2. The modulation of endothelial apolipoprotein E receptor 2 function or NO bioavailability may represent new interventions to prevent the nonthrombotic vascular occlusion and resulting cardiovascular disorders that afflict antiphospholipid syndrome patients.

Receptors involved in cell activation by antiphospholipid antibodies

The antiphospholipid syndrome (APS) is an autoimmune disease associated with arterial or venous thrombosis and/or recurrent fetal loss and is caused by pathogenic antiphospholipid antibodies (aPLA). The plasma protein β2-glycoprotein 1 (β2GP1) has been identified as a major target of aPLA associated with APS. Cell activation by aPLA appears to be a major pathogenic cause in the pathogenesis of APS. Receptors, co-receptors and accessory molecules are known to assist the pathogenic effects of aPLA. Members of the TLR family and the platelet receptor apolipoprotein E receptor 2' (apoER2'), a receptor belonging to the low-density lipoprotein receptor (LDL-R) family, as well as GPIbα, were identified as putative candidates for aPLA recognition. CD14, a co-receptor for TLR2 and TLR4, and annexin A2, a ubiquitous Ca2+ -binding protein that is essential for actin-dependent vesicle transport, could serve as important accessory molecules in mediating the pathogenic effects of aPLA. Finally, complement activation has been reported in association with the pathogenicity of APS. The relative contribution of these different mechanisms in the pathogenesis of APS is controversial. Here, we review the various in vivo and in vitro models that have been used to investigate the pathogenic mechanisms of aPLA in APS.

Treatment of refractory obstetric antiphospholipid syndrome: the state of the art and new trends in the therapeutic management

Objective

To date, there are no reliable data regarding the actual treatment received by women with refractory obstetric antiphospholipid syndrome (OAPS). The aim of this study was to assess current clinical evidence and new trends in the treatment of refractory OAPS.

Methods

A non-systematic but comprehensive literature search using relevant keywords was made to identify relevant articles published in English from different computerized databases: PubMed (Medline), Google Scholar electronic database search and The Cochrane Library, from January 2000 to March 2012. Studies on the treatment of poor obstetric outcomes in women with OAPS were included. Prospective randomized clinical trials, cohort studies, reviews, systematic reviews and meta-analysis were retrieved.

Results

A total of 130 articles were finally selected for this review, including 17 randomized clinical trials and four meta-analyses. The majority of articles were non-randomized original papers and basic and clinical reviews.

Conclusion

Up to 20% of women with OAPS do not receive the currently recommended therapeutic regimen. Unfortunately, well-designed studies regarding the usefulness of new drugs in refractory OAPS are scarce. Hydroxychloroquine and low-dose prednisolone appear to be useful when added to standard therapy. Current data do not support the use of intravenous immunoglobulins in this field. The role played by double anti-aggregant therapy, fondaparinux, vitamin D, pentoxifylline and TNF-targeted therapies should be tested in well-designed studies.

Vascular Pathophysiology in Hearing Disorders

The inner ear vasculature is responsible for maintenance of the blood-labyrinth barrier, transport of systemic hormones for ion homeostasis, and supplying nutrients for metabolic functions. Unfortunately, these blood vessels also expose the ear to circulating inflammatory factors resulting from systemic diseases. Thus, while the inner ear blood vessels are critical for normal function, they also are facilitating pathologic mechanisms that result in hearing and vestibular dysfunction. In spite of these numerous critical roles of inner ear vasculature, little is known of its normal homeostatic functions and how these are compromised in disease. The objective of this review is to discuss the current concepts of vascular biology, how blood vessels naturally respond to circulating inflammatory factors, and how such mechanisms of vascular pathophysiology may cause hearing loss.

Circulating cell-derived microparticles in severe preeclampsia and in fetal growth restriction

PROBLEM

The behavior of the circulating microparticles (cMP) in severe preeclampsia (PE) and fetal growth restriction (FGR) is disputed. METHOD OF STUDY  Non-matched case-control study. Seventy cases of severe PE/HELLP/FGR were compared to 38 healthy pregnant women. Twenty healthy non-pregnant women acted as a control. cMP were analyzed using flow cytometry. Results are given as total (annexin-A5-ANXA5+), platelet (CD41+), leukocyte (CD45+), endothelial (CD144+CD31+//CD41-), and CD41-negative cMP/μL of plasma. Antiphospholipid antibodies (aPL) were analyzed through usual methods.

RESULTS

Platelet and endothelial cMP increased in healthy pregnant women. PE whole group (PE±FGR) showed an increase in endothelial and CD41-negative, but not in platelet-derived, cMP. Comparing PE whole group versus healthy pregnant, we found cMP levels of endothelial and CD41- had increased. The cMP results obtained in PE group were similar to those of the PE whole group. Comparing PE group to isolated FGR, significant CD41-negative cMP increase was found in PE. According to its aPL positivity, a trend to decrease in leukocyte and endothelial-derived cMP was found in PE group.

CONCLUSION

Normal pregnancy is accompanied by endothelial and platelet cell activation. Endothelial cell activation has been shown in PE but not in isolated FGR. In PE, aPL may contribute to endothelial and possibly to leukocyte cell activation.

New Insights into the Molecular Basis of the Antiphospholipid Syndrome

Antiphospholipid syndrome is an autoimmune disease characterized by the presence of circulating antiphospholipid antibodies (aPL) that promote thrombosis, pregnancy complications and cardiovascular diseases. Alterations in the function of vascular cells induced by aPL underlie these outcomes. This review will discuss recent findings that indicate a novel mechanism by which aPL antagonize endothelial cell production of nitric oxide and thereby promote thrombosis.

Circulating cell-derived microparticles in women with pregnancy loss

PROBLEM

To analyze cell-derived microparticles (cMP) in pregnancy loss (PL), both recurrent miscarriages (RM) and unexplained fetal loss (UFL).

METHOD OF STUDY

Non-matched case-control study was performed at Vall d'Hebron Hospital. Cell-derived microparticles of 53 PL cases, 30 with RM, 16 with UFL, and 7 (RM + UFL), were compared to 38 healthy pregnant women. Twenty healthy non-pregnant women act as controls. Cell-derived microparticles were analyzed through flow cytometry. Results are given as total annexin (A5+), endothelial-(CD144+/CD31+ CD41-), platelet-(CD41+), leukocyte-(CD45+) and CD41- c-MP/μL of plasma. Antiphospholipid antibodies (aPLA) were analyzed according to established methods.

RESULTS

Comparing PL versus healthy pregnant, we observed a significant endothelial cMP decrease in PL. When comparing RM subgroup with controls, we observed significant decreases in endothelial cMP. When comparing the PL positive for aPLA versus PL-aPLA-negative, no cMP numbering differences were seen.

CONCLUSION

Pregnancy loss seems to be related to endothelial cell activation and/or consumption. A relationship between aPLA and cMP could not be demonstrated.

Antiphospholipid antibodies promote leukocyte-endothelial cell adhesion and thrombosis in mice by antagonizing eNOS via β2GPI and apoER2

In antiphospholipid syndrome (APS), antiphospholipid antibodies (aPL) binding to β2 glycoprotein I (β2GPI) induce endothelial cell-leukocyte adhesion and thrombus formation via unknown mechanisms. Here we show that in mice both of these processes are caused by the inhibition of eNOS. In studies of cultured human, bovine, and mouse endothelial cells, the promotion of monocyte adhesion by aPL entailed decreased bioavailable NO, and aPL fully antagonized eNOS activation by diverse agonists. Similarly, NO-dependent, acetylcholine-induced increases in carotid vascular conductance were impaired in aPL-treated mice. The inhibition of eNOS was caused by antibody recognition of domain I of β2GPI and β2GPI dimerization, and it was due to attenuated eNOS S1179 phosphorylation mediated by protein phosphatase 2A (PP2A). Furthermore, LDL receptor family member antagonism with receptor-associated protein (RAP) prevented aPL inhibition of eNOS in cell culture, and ApoER2-/- mice were protected from aPL inhibition of eNOS in vivo. Moreover, both aPL-induced increases in leukocyte-endothelial cell adhesion and thrombus formation were absent in eNOS-/- and in ApoER2-/- mice. Thus, aPL-induced leukocyte-endothelial cell adhesion and thrombosis are caused by eNOS antagonism, which is due to impaired S1179 phosphorylation mediated by β2GPI, apoER2, and PP2A. Our results suggest that novel therapies for APS can now be developed targeting these mechanisms.

Antiphospholipid syndrome; its implication in cardiovascular diseases: a review

Antiphospholipid syndrome (APLS) is a rare syndrome mainly characterized by several hyper-coagulable complications and therefore, implicated in the operated cardiac surgery patient. APLS comprises clinical features such as arterial or venous thromboses, valve disease, coronary artery disease, intracardiac thrombus formation, pulmonary hypertension and dilated cardiomyopathy. The most commonly affected valve is the mitral, followed by the aortic and tricuspid valve. For APLS diagnosis essential is the detection of so-called antiphospholipid antibodies (aPL) as anticardiolipin antibodies (aCL) or lupus anticoagulant (LA). Minor alterations in the anticoagulation, infection, and surgical stress may trigger widespread thrombosis. The incidence of thrombosis is highest during the following perioperative periods: preoperatively during the withdrawal of warfarin, postoperatively during the period of hypercoagulability despite warfarin or heparin therapy, or postoperatively before adequate anticoagulation achievement. Cardiac valvular pathology includes irregular thickening of the valve leaflets due to deposition of immune complexes that may lead to vegetations and valve dysfunction; a significant risk factor for stroke. Patients with APLS are at increased risk for thrombosis and adequate anticoagulation is of vital importance during cardiopulmonary bypass (CPB). A successful outcome requires multidisciplinary management in order to prevent thrombotic or bleeding complications and to manage perioperative anticoagulation. More work and reporting on anticoagulation management and adjuvant therapy in patients with APLS during extracorporeal circulation are necessary.

Atherosclerosis in primary antiphospholipid syndrome

Antiphospholipid syndrome (APS) is the most common cause of acquired thrombophilia, but experimental and clinical evidence accumulated over the years suggest that the clinical manifestations of APS go beyond those of a simple hypercoagulable state. Although still a controversial topic, the elevated risk of atherosclerosis in systemic lupus erythematosus seems little accounted for by the presence of antiphospholipid antibodies, whereas premature atherosclerosis has been addressed in few series of patients with primary APS. The available data in primary APS suggest that traditional risk factors for atherosclerosis are less involved in arterial disease, rather antiphospholipid antibodies appear as major players. Their effect on the coagulation system, the vessel wall and on the antioxidant/oxidant balance impairs vascular homeostasis, leading to premature arterial thickening.

Pathogenetic potential of antiphospholipid antibodies

Antiphospholipid antibodies are autoantibodies that recognize phospholipid-binding proteins such as beta2 glycoprotein (beta2GP)-I, prothrombin or annexins. These antibodies have been associated with arterial or venous thrombotic events and pregnancy morbidity. The molecular mechanisms responsible for the pathogenetic potential of these antibodies include: resistance to activated protein C, acquired Factor XII deficiency resulting in suppression of intrinsic fibrinolytic activity, activation of endothelial cells through the nuclear factor kappaB pathway leading to tissue factor upregulation, adhesion molecule and cytokine expression and activation of platelets. Opposite effects, such as the potentiation of the inhibitory action of beta2GPI on the activation of Factor XI, make the dynamics of the interaction of these antibodies with the coagulation system rather complex. Many of the above functions can be mediated by signaling through molecules of the tumor necrosis factor receptor family, such as CD40, which is recognized by purified anti-beta2GPI antibodies.

Serum complement activation on heterologous platelets is associated with arterial thrombosis in patients with systemic lupus erythematosus and antiphospholipid antibodies

Complement plays a major role in inflammation and thrombosis associated with systemic lupus erythematosus (SLE) and the antiphospholipid syndrome (APS). A cross-sectional retrospective analysis was performed to evaluate serum complement fixation on platelets and thrombotic incidence using banked sera and clinical data from patients with SLE (n = 91), SLE with antiphospholipid antibodies (aPL) or APS (n = 78) and primary aPL (n = 57) or APS (n = 96). In-situ complement fixation was measured as C1q and C4d deposition on heterologous platelets using an enzyme-linked immunosorbent assay approach. Platelet activation by patient serum in the fluid phase was assessed via serotonin release assay. Enhanced in-situ complement fixation was associated with the presence of IgG aPL and IgG anti-beta2 glycoprotein 1 antibodies (P < 0.05) and increased platelet activation (P < 0.005). Moreover, enhanced complement fixation, especially C4d deposition on heterologous platelets, was positively associated with arterial thrombotic events in patients with SLE and aPL (P = 0.039). Sera from patients with aPL possess an enhanced capacity for in-situ complement fixation on platelets. This capacity may influence arterial thrombosis risk in patients with SLE.

Are endothelial microparticles potential markers of vascular dysfunction in the antiphospholipid syndrome?

Vascular dysfunction is key to the development of thrombosis in the antiphospholipid syndrome. This has been largely demonstrated by the upregulation of various cell surface and intracellular signalling molecules, as well as proinflammatory cytokine release from activated endothelial cells. Endothelial microparticles (EMP) are a further marker of endothelial activation but have been less extensively studied. We summarise evidence suggesting that these microparticles may be critical effectors of thrombosis in the antiphospholipid syndrome. There is evidence that levels of EMP are raised in patients with circulating antiphospholipid antibodies and that these EMP may be prothrombotic. The balance between markers of endothelial dysfunction (including EMP and circulating endothelial cells) and markers of repair such as circulating endothelial progenitor cells may be abnormal in patients with APS but this has not been proved and requires further study.

Accelerated atherosclerosis, arterial thromboembolism, and preventive strategies in systemic lupus erythematosus

With improved disease survival, arterial thromboembolism has become an important cause of morbidity in patients with systemic lupus erythematosus (SLE). A number of conventional and non-conventional risk factors are associated with accelerated atherosclerosis. Regular surveillance and control of traditional risk factors is mandatory, and so is the appropriate use of the statins, anti-malarial agents, anti-platelet agents, and anti-coagulation for primary and secondary prevention of arterial thromboembolism in SLE patients. Judicious use of corticosteroids, calcineurin inhibitors, hormonal replacement therapy, and the cyclooxygenase 2 inhibitors is equally important.

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.

Circulating microparticles, lupus anticoagulant and recurrent miscarriages

Pregnancy is a pro-inflammatory/hypercoagulable state. Impairment of trophoblastic invasion and placental microthrombi are involved mechanisms in the pathogenesis of recurrent miscarriages (RM). Although in RM related to antiphospholipid antibodies (aPL) non-thrombotic mechanism seems to play an important role as well, we focused this review on the thrombotic mechanisms of RM related to aPL. Thus, in cases of RM related to aPL, placental injury produces inflammatory changes in endothelial cells. Endothelial dysfunction has been shown by increased plasma levels of ICAM-1/VCAM-1 and E-selectin. In RM associated with aPL, the thrombogenic mechanisms included different pathways: protein C inhibition, annexin-5 displacement, blocking of beta(2)GP1 anticoagulant activity and tissue factor upregulation. A new marker/causative agent of RM by itself or in relation to lupus anticoagulant (LA) has risen: circulating microparticles. Microparticles are a heterogeneous group of small, membrane-coated vesicles with a diameter of 0.1-1 microm. Microparticles are released from the cellular membrane during cell activation/apoptosis. Exposition of phospholipids in the outer membrane leaflet could explain the role of microparticles in the thrombotic events. Microparticles have been associated with RM. Microparticles are increased in women with RM when compared with healthy pregnant women. A relationship between aPL and activated endothelial cells (EC) occurs, as well as between EC and circulating microparticles. Interestingly, microparticles induced coagulation in vitro via tissue factor, especially in plasmas with LA. Finally, the relationship between EC, microparticles, LA and RM is revised.

In vivo inhibition of antiphospholipid antibody-induced pathogenicity utilizing the antigenic target peptide domain I of beta2-glycoprotein I: proof of concept

SUMMARY OBJECTIVES

In the antiphospholipid syndrome (APS), the immunodominant epitope for the majority of circulating pathogenic antiphospholipid antibodies (aPLs) is the N-terminal domain I (DI) of beta(2)-glycoprotein I. We have previously shown that recombinant DI inhibits the binding of aPLs in fluid phase to immobilized native antigen, and that this inhibition is greater with the DI(D8S/D9G) mutant and absent with the DI(R39S) mutant. Hence, we hypothesized that DI and DI(D8S/D9G) would inhibit aPL-induced pathogenicity in vivo.

METHODS

C57BL/6 mice (n = 5, each group) were injected with purified IgG derived from APS patients (IgG-APS, 500 microg) or IgG from normal healthy serum (IgG-NHS) and either recombinant DI, DI(R39S), DI(D8S/D9G), or an irrelevant control peptide (at 10-40 microg). Outcome variables measured were femoral vein thrombus dynamics in treated and control groups following standardized vessel injury, expression of vascular cell adhesion molecule-1 (VCAM-1) on the aortic endothelial surface, and tissue factor (TF) activity in murine macrophages.

RESULTS

IgG-APS significantly increased thrombus size as compared with IgG-NHS. The IgG-APS thrombus enhancement effect was abolished in mice pretreated with recombinant DI (P

CONCLUSION

Our findings in this proof-of-concept study support the development of recombinant DI or the novel variant DI(D8S/D9G) as a potential future therapeutic agent for APS.

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Key Words Collapse

MESH Headings

• Animals
• Antibodies, Antiphospholipid/immunology
• Antibodies, Antiphospholipid/physiology
• Enzyme-Linked Immunosorbent Assay
• Macrophages, Peritoneal/metabolism
• Mice
• Mice, Inbred C57BL
• Thromboplastin/metabolism
• beta 2-Glycoprotein I/chemistry
• beta 2-Glycoprotein I/metabolism

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Grants

• R01 AR056745 NIAMS NIH HHS
• Arthritis Research UK

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Affiliation(s)

Y Ioannou Centre for Rheumatology Research, Windeyer Building, University College London, London, UK.
Z Romay-Penabad
C Pericleous
I Giles
E Papalardo
G Vargas
T Shilagard
D S Latchman
D A Isenberg
A Rahman
S Pierangeli

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The altered expression of inflammation-related molecules and secretion of IL-6 and IL-8 by HUVEC from newborns with maternal inactive systemic lupus erythematosus is modified by estrogens

Systemic lupus erythematosus (SLE) predominantly affects women, especially those in reproductive age. Genetic contributions to disease susceptibility as well as immune dysregulation, particularly persistent inflammatory responses, are considered essential features. Our aim was to determine whether human umbilical vein endothelial cells (HUVEC) isolated from healthy newborns to women with inactive SLE show inflammation-related abnormalities that might lead to an early development of SLE in the offsprings. HUVEC isolated from six women with inactive SLE were stimulated with 2.5 ng/mL of TNF-alpha and/or physiological and pharmacological doses of 17-I(2) estradiol (E2). Then the expression of VCAM-1, ICAM-1, E-selectin, toll-like receptor-9 (TLR-9), heat shock protein 70 (HSP70) and HSP90 were measured. The concentrations of IL-6, IL-8, and IL-10 were also determined in maternal serum and in TNF-alpha stimulated and non-stimulated HUVEC culture supernatant. HUVEC from children with no family history of autoimmune disease served as controls. Our results showed that in HUVEC from SLE+ mothers, a constitutively low expression of adhesion molecules was enhanced by TNF-alpha treatment. The E2 (1 ng/mL) increased the expression of adhesion molecules but had no effect upon TNF-alpha-treated cells. IL-6 was constitutively higher in SLE+ HUVEC, whereas IL-8 was lower; E2 treatment diminished the latter. The E2 had no effect upon IL-6 and IL-8 secretions in TNF-alpha-treated cells. SLE+ HUVEC showed a disordered cytoskeleton and overexpressed HSP70, HSP90, and TLR-9. Our results indicate that endothelial cells of newborns to SLE+ mothers are in a proinflammatory condition which can be upregulated by estrogens.

The tissue plasminogen activator gene promoter: a novel tool for radiogenic gene therapy of the prostate?

BACKGROUND

Radiation therapy is a treatment modality routinely used in cancer management so it is not unexpected that radiation-inducible promoters have emerged as an attractive tool for controlled gene therapy. The human tissue plasminogen activator gene promoter (t-PA) has been proposed as a candidate for radiogenic gene therapy, but has not been exploited to date. The purpose of this study was to evaluate the potential of this promoter to drive the expression of a reporter gene, the green fluorescent protein (GFP), in response to radiation exposure.

METHODS

To investigate whether the promoter could be used for prostate cancer gene therapy, we initially transfected normal and malignant prostate cells. We then transfected HMEC-1 endothelial cells and ex vivo rat tail artery and monitored GFP levels using Western blotting following the delivery of single doses of ionizing radiation (2, 4, 6 Gy) to test whether the promoter could be used for vascular targeted gene therapy.

RESULTS

The t-PA promoter induced GFP expression up to 6-fold in all cell types tested in response to radiation doses within the clinical range.

CONCLUSIONS

These results suggest that the t-PA promoter may be incorporated into gene therapy strategies driving therapeutic transgenes in conjunction with radiation therapy.

Patients with primary antiphospholipid antibody syndrome and without associated vascular risk factors present a normal endothelial function

INTRODUCTION

Primary antiphospholipid antibody syndrome (PAPS) is characterized by venous or arterial thrombosis and positive antiphospholipid antibodies. It is controversial whether PAPS patients have early atherosclerosis. Endothelial dysfunction is an early event in the natural history of atherosclerosis. Aim of our study was to compare endothelial function of patients with PAPS and no associated risk factors with that of age- and sex-matched controls.

MATERIALS AND METHODS

Patients with PAPS, carefully selected to exclude all known risk factors for cardiovascular diseases, estrogen therapy, pregnancy, intake of drugs affecting endothelial function, vitamins or antioxidants, were included in a case-control study. Controls were age- (+/-5 years) and sex-matched subjects with the same exclusion criteria but without PAPS. Flow-mediated dilation of the brachial artery and some plasmatic markers of endothelial and platelet activation were measured. Measures are expressed as mean+/-SEM.

RESULTS

Twenty cases (mean age 42+/-4.0 years, 11 females) and 39 controls (mean age 41+/-2.9, 22 females) were studied. FMD was 5.7+/-0.8% in cases (95% CI: 4.1 to 7.3) and 6.8+/-0.5% (5.7 to 7.9) in controls (p=NS). Plasma von Willebrand factor was 128+/-11.3% and 134.2+/-16.1% in cases and controls, respectively (p=NS). Soluble P-selectin and soluble CD40L were 94.1+/-4.9 ng/ml and 0.7+/-0.1 ng/ml in cases and 87.7+/-4.0 ng/ml and 1.0+/-0.2 in controls, respectively (p=NS). In a substudy, circulating progenitor and mature endothelial cells were comparable between the two groups.

CONCLUSIONS

Endothelial function in patients with PAPS and no associated risk factors is similar to that of age- and sex- matched controls. These data suggest that the alterations leading to thrombosis in PAPS concern primarily the clotting system.

Antiphospholipid antibodies induce vascular functional changes in mice: a mechanism of vascular lesions in antiphospholipid syndrome?

Abstract

A premature atherosclerosis has been presumed in patients with antiphospholipid syndrome. The potential role of antiphospholipid antibodies in the development of atheroma is rather controversial. In this study, we tested the hypothesis that antiphospholipid antibodies could induce atherosclerosis via vascular functional changes. CD1 mice received one single injection of antiphospholipid monoclonal antibodies derived from male (BXSB × NZW) F1 mice with a lupus-like disease associated with an antiphospholipid syndrome and coronary artery disease. One week later, first-order mesenteric arteries (diameter 220–260 μm) were isolated and mounted on a small-vessel myograph for the measurement of the relaxation responses to acetylcholine or the NO donor nitroprusside after precontraction by phenylephrine. Five out of eight antiphospholipid monoclonal antibodies reduced the response to acetylcholine compared with control mice, and this effect was especially marked with one of them. No change in the response to nitroprusside was observed. The impairment was maintained after 3 weeks of treatment and appeared related to a moderate decrease in NO-mediated responses and a marked decrease in prostanoid-mediated relaxations. These vascular functional changes could be prevented by chronic treatment with statins or aspirin. These data could constitute additional elements supporting a direct pathogenic role of antiphospholipid antibodies. We suggest that a sub-population of these autoantibodies could be responsible for the endothelial dysfunction observed in antiphospholipid syndrome.

Early atheroma in primary and secondary antiphospholipid syndrome: an intrinsic finding

OBJECTIVES

The relationship between atherosclerosis and the antiphospholipid syndrome (APS) is unclear. This study compared intima-media thickness (IMT), arterial stiffness, and presence of plaques in APS patients and controls to evaluate the risk of atherosclerosis in this patient population. The study also explored the relationship between these parameters and cardiovascular risk factors.

METHODS

Carotid and femoral IMT and stiffness were measured in 58 APS patients and 58 controls. In addition, antiphospholipid antibodies and cardiovascular risk factors were investigated and other systemic lupus erythematosus (SLE)-related serologic parameters were measured. Details of the patients' previous medical history and information regarding disease treatment were analyzed.

RESULTS

A significant difference was found between IMT, arterial stiffness, and the presence of plaques in patients and controls (P<0.05). All of these parameters were independent of cardiovascular risk factors. No differences in these parameters were found between patients with primary APS and those with secondary APS, or between patients with thrombosis and those with obstetric manifestations. There was no correlation between SLE disease activity and atheroma. Patients with plaques had taken a lower total dose of corticosteroids and/or hydroxychloroquine.

CONCLUSIONS

Some markers of early atherosclerosis could be detected in both primary and secondary APS, irrespective of clinical manifestations. These data suggest that atherosclerosis might be an intrinsic finding in APS patients, independent of cardiovascular risk factors, and that immunosuppressive treatment may prevent atherosclerosis.

Pregnancies Complicated with Antiphospholipid Syndrome: The Pathogenic Mechanism of Antiphospholipid Antibodies: A Review of the Literature

There are several possible mechanisms by which antiphospholipid antibodies (aPL) may have adverse effects on placental functions. Examination of placentas and first-trimester decidua from antiphospholipid syndrome-complicated pregnancies has found little evidence of specific thrombotic placental pathology. It is now generally accepted that the clinically relevant aPL bind to proteins with affinity for phospholipids. The most important epitope for antiphospholipid syndrome-related aPL resides on beta2-glycoprotein-I (beta2GPI). aPL detected by anti-beta2GPI assays are associated with fetal loss. During differentiation to syncytium, trophoblasts express cell membrane anionic phospholipids that can bind beta2GPI. Adhered beta2GPI can be recognized by the antibodies that, once bound, interfere with trophoblast cell maturation, resulting in defective placentation. The improved outcome of pregnancies treated with heparin stimulated interest on the drug's mechanism of action. Several mechanisms could explain its beneficial effects in addition to a direct effect of heparin on the coagulation cascade. It might reduce the binding of aPL, inflammation by inhibiting complement activation, and might facilitate implantation. Further investigations are needed to better understand how aPL induce obstetric complications and to better clarify the functional role of heparin in the human placenta, leading to more successful therapeutic options.

Anti-beta2GPI-antibody-induced endothelial cell gene expression profiling reveals induction of novel pro-inflammatory genes potentially involved in primary antiphospholipid syndrome

OBJECTIVE

To determine the effects of primary antiphospholipid syndrome (PAPS)-derived anti-beta(2)GPI antibodies on gene expression in human umbilical vein endothelial cells (HUVEC) by gene profiling using microarrays.

METHODS

Anti-beta(2)GPI antibodies purified from sera of patients with PAPS or control IgG isolated from normal subjects were incubated with HUVEC for 4 h before isolation of RNA and processing for hybridisation to Affymetrix Human Genome U133A-2.0 arrays. Data were analysed using a combination of the MAS 5.0 (Affymetrix) and GeneSpring (Agilent) software programmes. For selected genes microarray data were confirmed by real-time PCR analysis or at the protein level by ELISA.

RESULTS

A total of 101 genes were found to be upregulated and 14 genes were downregulated twofold or more in response to anti-beta(2)GPI antibodies. A number of novel genes not previously associated with APS were induced, including chemokines CCL20, CXCL3, CX3CL1, CXCL5, CXCL2 and CXCL1, the receptors Tenascin C, OLR1, IL-18 receptor 1, and growth factors CSF2, CSF3 IL-6, IL1beta and FGF18. The majority of downregulated genes were transcription factors/signalling molecules including ID2. Quantitative real-time RT-PCR analysis confirmed the microarray results for selected genes (CSF3, CX3CL1, FGF18, ID2, SOD2, Tenascin C).

CONCLUSIONS

This study reveals a complex gene expression response in HUVEC to anti-beta(2)GPI antibodies with multiple chemokines, pro-inflammatory cytokines, pro-thrombotic and pro-adhesive genes regulated by these antibodies in vitro. Some of these newly identified anti-beta(2)GPI antibody-regulated genes could contribute to the vasculopathy associated with this disease.

Cardiac dysfunction in patients with systemic lupus erythematosus and antiphospholipid syndrome

OBJECTIVE

To comparatively assess the parameters of systolic and diastolic cardiac function in patients with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS).

METHODS

Consecutive patients (n=74) who were free of cardiovascular symptoms were divided into four groups: (1) SLE (n=23); (2) SLE with antiphospholipid antibodies (aPL; n=18); (3) SLE with APS (n=20); and (4) primary antiphospholipid syndrome (PAPS; n=13). Pulsed, continuous, colour Doppler echocardiography, and M-mode and B-mode studies were performed.

RESULTS

Left ventricular end diastolic and end systolic dimensions were higher in SLE as compared with patients with PAPS (p=0.022 and 0.022, respectively), with a trend towards a lower fractional shortening in SLE (p=0.07), suggesting systolic dysfunction. Parameters of diastolic function were more impaired in patients with APS, reflected by lower left ventricular and right ventricular E wave to A wave (E:A) ratios in patients with APS (groups 3, 4) compared with those without APS (groups 1, 2; 1.15 (0.40) v 1.49 (0.43), p=0.001 and 1.19 (0.31) v 1.49 (0.41), p=0.001, respectively) and a more prolonged left ventricular isovolumic relaxation time (IVRT; 94.2 (24.6) v 84.4 (17) ms, respectively, p=0.055). Patients with APS were older than those without APS (47.12 (14.86) v 34.29 (12.6), p=0.0001). Patients with SLE were younger than those with PAPS (38.19 (14.68) v 48.53 (13.97), p=0.023).

CONCLUSION

Abnormal echocardiographic findings were detected frequently in asymptomatic patients with SLE or PAPS. Although patients with SLE were younger, left ventricular systolic function was more impaired in patients with SLE compared with those with PAPS, whereas left ventricular and right ventricular diastolic function, as reflected by IVRT and E:A ratios, were significantly more impaired in patients with APS.