Acquired activated protein C resistance, high tissue factor expression, and hyper-homocysteinemia in systemic lupus erythematosus

Anti-protein C antibodies and acquired protein C resistance in SLE: novel markers for thromboembolic events and disease activity?

OBJECTIVES

Risk factors for thromboembolism in SLE are poorly understood. We hypothesized a possible role for protein C, based on its dual activity in inflammation and haemostasis and on the evidence of an association between acquired activated protein C (APC) resistance (APCR) and high-avidity anti-protein C antibodies (anti-PC) with a severe thrombotic phenotype in venous thrombosis APS patients.

METHODS

In a cross-sectional study of 156 SLE patients, the presence and avidity of IgG anti-PC was established by in house-ELISA, and APCR to exogenous recombinant human APC (rhAPC) and Protac (which activates endogenous protein C) was assessed by thrombin generation-based assays. Associations with aPL profile, thrombotic history and disease activity (BILAG and SLEDAI-2K) were also established.

RESULTS

Anti-PC were detected in 54.5% of patients and APCR in 59%. Anti-PC positivity was associated with APCR to both rhAPC (P <0.0001) and Protac (P =0.0001). High-avidity anti-PC, detected in 26.3% of SLE patients, were associated with APCR in patients with thrombosis only (P <0.05), and with the development of thrombosis over time (range: 0-52 years; P =0.014). High-avidity anti-PC levels correlated with SLEDAI-2K (P =0.033) and total BILAG (P =0.019); SLEDAI-2K correlated inversely with APCR to Protac (P =0.004).

CONCLUSION

Anti-PC occur in patients with SLE, independently of aPL profile, and are associated with APCR. High-avidity anti-PC are associated with thrombosis and with active disease and might prove a novel marker to monitor the risk of thrombosis and disease progression in SLE.

Serum/plasma homocysteine levels in patients with systemic lupus erythematosus: a systematic review and meta-analysis

Published studies have shown contradictory results in the association of serum/plasma levels of homocysteine (HCY) with systemic lupus erythematosus (SLE). This study is to systematically evaluate the association of serum/plasma HCY levels in SLE. A search was done using PubMed, Embase, Web of Science, and ScienceDirect databases up to 7 April 2019. Thirty-six articles including 2919 SLE patients and 3120 healthy controls were finally included in this meta-analysis. The HCY levels were significantly higher in SLE patients than in healthy controls (P < 0.001). The subgroup analysis revealed that Asian, African, Arab, Mixed, White and others as well as ages (< 35 and ≥ 35) had significant higher HCY levels in SLE patients than in the healthy controls. The study indicated that patients with disease activity index scores < 8 (P < 0.001) and ≥ 8 (P = 0.003) of SLE had significant higher HCY levels as compared with the healthy controls. It was also revealed that disease duration in SLE patients for < 10 and ≥ 10 years (P < 0.001) had significant higher HCY levels as compared with the healthy controls. A significant higher HCY level for body mass index (< 23 and ≥ 23) was found as well as measurement type in SLE patients than healthy controls. This meta-analysis demonstrated higher HCY levels in patients with SLE than healthy controls, suggesting a possible role of HCY in the disease.Key Points• Homocysteine (HCY) is closely related to the mechanisms of systemic lupus erythematosus (SLE).• This study reveals a significant correlation between HCY levels and the various indexes of disease activity.• This study reveals that medication may influence HCY levels in SLE.• This study also discovers that the subgroup analysis of all the factors influences the HCY levels in SLE patients.

[Thrombophilia in systemic lupus erythematosus: A case-control study]

INTRODUCTION

To investigate the thrombotic tendency in patients with systemic lupus erythematosus (SLE) by evaluating congenital and acquired abnormalities with an increased risk of thrombosis.

PATIENTS AND METHODS

A total of 53 patients with SLE were included in the study. Fifty-three healthy controls paired by age and sex were assessed. Anticardiolipin antibodies (aCL), anti β2 glycoprotein (aβ2GP), lupus anticoagulant (LAC), protein C (PC), protein S (PS), antithrombin (AT), acquired activated protein C, and homocysteinemia were evaluated. Comparisons for categorical variables were analyzed by Chi² and student tests.

RESULTS

The patients were all female and had a mean age of 30.6 years (16/58). The healthy controls were all female and their mean age was 30.8 years (17/56). Five patients (9.4%) developed venous thrombosis during the 24 months of follow-up. The antiphospholipid antibodies were positive in 17 patients (32.1%) and negative in all healthy controls (P=0.01). PS deficiency was noted in 17 patients (32.1%) and in 5 controls (P=0.004). Hyperhomocysteinemia was noted in 16 patients (30.2%) versus 3 controls (5.6%) (P=0.002). Test for PC deficiency and acquired activated protein C showed no significant difference between the two groups. No AT deficiency was found in the patients. The study of clinical and biological correlations based on the presence and absence of thrombophilic parameters concluded to a significant association between Protein C deficit and thrombosis (P=0.02) and acquired activated protein C resistance and thrombosis (P=0.04). There was no significant association between the APL and thrombosis.

CONCLUSION

Thrombophilic abnormalities were significantly more frequent in lupus patients than in healthy controls. Thrombotic events were significantly associated with PC deficit and acquired protein C resistance. There was no correlation between antiphospholipid antibodies and thrombosis.

Hyperhomocysteinemia: a cardiovascular risk factor in autoimmune diseases?

Epidemiological studies conducted over the past 25 years have provided ample support for the association of mild hyperhomocysteinemia (HHcy) with an elevated risk of atherothrombosis. Since autoimmune disorders (AD) are frequently associated with relevant and early signs of atherothrombotic damage not adequately explained by the traditional risk factors involved in the onset of cardiovascular disease (CVD), a large interest has been shown to the putative role of mild HHcy in this setting. On the basis of such considerations, we focused the attention on the relationship between homocysteine (Hcy) and CVD in patients affected with autoimmune diseases, reviewing the most recent literature data and also providing our original experience. Although the large amount of available studies clearly shows that HHcy represents a common finding in patients affected with several autoimmune diseases, the actual role of Hcy in the development of CVD in the course of AD is not clear yet, perhaps, with the only exception of the systemic lupus erythematosus. In the other conditions, the role of Hcy in the pathogenesis of vascular complications is still a matter of debate, as the result of conflicting reports and/or lack of an adequate body of investigation. Lupus (2007) 16, 852—862.

Poor 1-year outcomes after percutaneous coronary interventions in systemic lupus erythematosus: report from the National Heart, Lung, and Blood Institute Dynamic Registry

BACKGROUND

Women with systemic lupus erythematosus (SLE) have premature and accelerated atherosclerosis. Although percutaneous coronary intervention (PCI) is used frequently to treat coronary artery disease in SLE, little is known regarding PCI outcomes immediately after PCI and after discharge.

METHODS AND RESULTS

Baseline demographic, procedure-related, and adverse outcome data on consecutive patients undergoing PCI during 5 recruitment "waves" of the National Heart, Lung, and Blood Institute Dynamic Registry across 23 clinical centers were collected. SLE patients (n=28) were compared with non-SLE patients (n=3385). SLE patients were younger and more often female in comparison with non-SLE patients undergoing PCI. SLE patients were less likely than non-SLE patients to have hyperlipidemia but had a similar prevalence of hypertension, diabetes mellitus, and tobacco use. The prevalence of multivessel disease was similar between groups. Initial intervention success (by angiographic definition) was not significantly different between groups. At 1 year, SLE patients were more likely to experience a myocardial infarction (15.6% versus 4.8%, P=0.01) and more often required repeat PCI (31.3% versus 11.8%, P=0.009) than non-SLE patients, even after adjustment for important covariates.

CONCLUSIONS

SLE patients had significantly worse cardiovascular outcomes at 1 year than non-SLE patients. Even considering the small number of SLE patients, these differences were striking. Further study is warranted to explore other factors potentially accounting for this disparity, including SLE disease activity and duration, presence of hypercoagulable state, and immunosuppressive therapy.

The hemostatic balance in HIV-infected patients with and without antiretroviral therapy: partial restoration with antiretroviral therapy

The incidence of arterial and venous thrombosis in HIV-infected patients is increased compared to healthy controls. In this cross-sectional analysis we measured markers of endothelial cell activation, thrombin generation, fibrinolysis and anticoagulation combined with endogenous thrombin potential (ETP) and activated protein C sensitivity ratio (APCsr) as more global markers. We included 160 consecutive HIV-infected patients with a median age of 46 years (range, 27-77), of whom 92% were male, 74% Caucasian, 11% African American, 9% Hispanic, and 6% Asian. Homosexual contact was the main transmission mode. Seventy percent of patients were using combined antiretroviral therapy (cART). In 83% of patients laboratory markers outside the normal range for a non-HIV-infected population were observed. Significant lower levels of von Willebrand factor (vWF; p = 0.03), factor VIII (p < 0.0001), D-dimer (p = 0.01), and ETP (p = 0.01) were observed in HIV-infected patients on cART compared to patients not on cART. Significant lower levels of protein C (p = 0.05) and free protein S (p < 0.0001), and increased APCsr (p < 0.0001) were found in the HIV-infected patients not on cART. A single association was observed between raised levels of fibrinogen and use of a protease inhibitor (p = 0.002). No significant difference was observed in the percentage of patients with laboratory markers outside the normal range between patients using cART-regimens containing abacavir, stavudine, or didanosine and those with other nucleoside reverse transcriptase inhibitors. Although the prevalence of coagulation abnormalities was lower in HIV-infected patients using cART, a considerable proportion of HIV-infected patients on cART show endothelial cell activation and increased APCsr, suggestive of a persistent procoagulant state.

[Association of tow thrombotic risk factors: factor V Leiden and hyperhomocysteinemia. A case report]

The identification of constitutional and/or acquired risk factor is of major importance in the treatment of thromboembolic disease in young people; it contributes to evaluate the risk of recurrence and to define the period of oral prophylactic anticoagulant treatment. Several congenital or acquired abnormalities of haemostasis are actually defined. In this paper, we report the case of a 34-year-old man who developed a deep venous thrombosis, five months before the diagnosis of megaloblastic anemia, probably due to pernicious anemia. The thrombosis was partially explained by the acquired hyperhomocysteinemia induced by vitamin B12 deficiency. Moreover, activated protein C resistance due to factor V Leiden, was revealed in our patient. This latter improved under anticoagulant treatment combined with vitamin B12. Combination in one individual, of different risk factors predisposing to inherited and/or acquired thrombophilia, results in increased risk for thrombo-embolic disease, suggesting synergic interaction between these factors.

Endothelial cell apoptosis in systemic lupus erythematosus: a common pathway for abnormal vascular function and thrombosis propensity

Women with systemic lupus erythematosus (SLE) are at risk for premature atherothrombosis independent of Framingham risk factors. We investigated whether endothelial cell (EC) apoptosis predicts abnormal vasomotor tone and contributes to circulating tissue factor (TF) levels in this disease. Brachial artery flow-mediated dilation (FMD) and nitroglycerin-mediated dilation were determined in women with SLE, healthy control subjects, and subjects with coronary artery disease (CAD) (n = 43/group). Quantification of circulating apoptotic ECs was performed by flow cytometry (CD146+ cells that stained for Annexin V [CD146AnnV+]) and immunofluorescent microscopy. Plasma TF was measured by enzyme-linked immunosorbent assay (ELISA). Compared with healthy control and CAD subjects, patients with SLE had higher numbers of circulating CD146AnnV+ cells (10 ± 3, 18 ± 5, and 89 ± 32 cells/mL, respectively, mean ± SEM; P &lt; .01). Increased CD146AnnV+ cells correlated strongly with abnormal vascular function (P = .037). After adjusting for known predictors of endothelial function, CD146AnnV+ was the only variable that predicted FMD (β = –4.5, P &lt; .001). Increased CD146AnnV+ was strongly associated with elevated levels of circulating TF (r = .46, P = .002). Circulating apoptotic ECs are elevated in young women with SLE and strongly correlate with markedly abnormal vascular function and elevated TF levels. Heightened endothelial apoptosis may represent an important mechanism for development of atherothrombosis in SLE.