Homocysteine, antiphospholipid antibodies and risk of thrombosis in patients with systemic lupus erythematosus

Hematological manifestations of antiphospholipid syndrome: Going beyond thrombosis

Thrombotic complications are a hallmark of antiphospholipid syndrome (APS). These vascular - arterial, venous, and/or small vessel - complications are well described and known to hematologists and healthcare providers caring for patients with this disease. In this review, we shed light on other hematological manifestations of the disease, including bleeding, thrombocytopenia, autoimmune hemolytic anemia, and thrombotic microangiopathy syndromes. While these manifestations are not bona fide clinical criteria for the diagnosis of APS, they frequently interact and contribute to the complexity of clinical management of APS.

[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.

Transiently positive anticardiolipin antibodies and risk of thrombosis in patients with systemic lupus erythematosus

Fluctuations in the titers of anticardiolipin antibodies (aCL) have been reported in systemic lupus erythematosus (SLE) patients, but their relation with thrombosis is not completely understood. Prospective inception cohort of 237 patients with SLE (American College of Rheumatology criteria). Positivity for antiphospholipid antibodies (aPL) was defined according to Sapporo criteria. aCL was defined as persistently positive when more than two-thirds of the determinations were positive during follow-up. Patients were classified into four groups: A [positive lupus anticoagulant (LA)], B (negative LA and persistently positive aCL), C (negative LA and transiently positive aCL) and D (negative LA and aCL). Of these 237 patients, 211 (89%) patients were women. Median age at diagnosis and follow-up were 32 (2—78) and 10 (1—31) years, respectively; 33 (13.9%), 23 (9.7%), 42 (17.7%) and 139 (58.6%) patients were classified in groups A, B, C and D, respectively. Thirty (12.6%) and 23 (9.7%) patients suffered arterial and venous thrombotic events, respectively. Adjusted risk for arterial thrombosis was increased in groups A [odds ratio (OR) 15.69, 95% confidential interval (CI) 4.79—51.42, P < 0.001] and B (OR 7.63, 95% CI 2.00—29.08, P = 0.003), but not in group C when compared with group D. Adjusted risk of venous thrombosis was increased in group A (OR 4.24, 95% CI 1.36—13.20, P = 0.013), but not in groups B or C when compared with group D. Risk of thrombosis is not increased in SLE patients with negative LA and transiently positive aCL, even fulfilling Sapporo laboratory criteria, when compared with aPL-negative SLE patients. Lupus (2007) 16, 810—816.

Effect of antimalarials on thrombosis and survival in patients with systemic lupus erythematosus

Antimalarials have shown beneficial effects on systemic lupus erythematosus (SLE) activity. Our aim was to investigate whether antimalarials protect against thrombosis and influence survival in SLE patients. A prospective cohort including 232 patients with SLE were included in the study at the time of lupus diagnosis. End points were documented thrombosis and death due to any cause. A Cox regression-multiple-failure time survival analysis model was fitted to establish the effect of antimalarials on the development of thrombosis. Kaplan-Meier survival curves and propensity score adjusted-Cox regression analysis were performed to investigate the effect of antimalarials use on survival. Of our subjects, 204 patients (88%) were women. 230 patients (99%) were white. 150 patients (64%) had ever received antimalarials. Median time on antimalarials was 52 months (range three to 228 months). The Cox multiple-failure time survival analysis showed that taking antimalarials was protective against thrombosis (HR 0.28, 95%CI 0.08-0.90), while aPL-positivity (HR 3.16, 95%CI 1.45-6.88) and previous thrombosis (HR 3.85, 95%CI 1.50-9.91) increased the risk of thrombotic events. Twenty-three patients died, 19 of whom (83%) had never received antimalarials. No patient treated with antimalarials died of cardiovascular complications. Cumulative 15-year survival rates were 0.68 for never versus 0.95 for ever treated patients ( P < 0.001). Age at diagnosis and propensity score-adjusted HR for antimalarials ever versus never users was 0.14 (95%CI 0.04-0.48). Our study shows a protective effect of antimalarials against thrombosis and an increased survival of SLE patients taking these drugs. These data support the routine use of antimalarials in all patients with SLE.

Cardiovascular involvement in autoimmune diseases

Autoimmune diseases (AD) represent a broad spectrum of chronic conditions that may afflict specific target organs or multiple systems with a significant burden on quality of life. These conditions have common mechanisms including genetic and epigenetics factors, gender disparity, environmental triggers, pathophysiological abnormalities, and certain subphenotypes. Atherosclerosis (AT) was once considered to be a degenerative disease that was an inevitable consequence of aging. However, research in the last three decades has shown that AT is not degenerative or inevitable. It is an autoimmune-inflammatory disease associated with infectious and inflammatory factors characterized by lipoprotein metabolism alteration that leads to immune system activation with the consequent proliferation of smooth muscle cells, narrowing arteries, and atheroma formation. Both humoral and cellular immune mechanisms have been proposed to participate in the onset and progression of AT. Several risk factors, known as classic risk factors, have been described. Interestingly, the excessive cardiovascular events observed in patients with ADs are not fully explained by these factors. Several novel risk factors contribute to the development of premature vascular damage. In this review, we discuss our current understanding of how traditional and nontraditional risk factors contribute to pathogenesis of CVD in AD.

The relationship between plasma homocysteine level and HLA-B51 in patients with Behcet's disease: a case-control study

BACKGROUND

Various coagulation disorders have been reported to explain hypercoagulability state in Behcet's disease (BD). A possible negative association between human leukocyte antigen (HLA)-B51 and increased homocysteine level has been suggested in a previous report from Iranian patients with BD. The aim of this study was to find any possible relationship between plasma homocysteine levels and HLA-B51.

METHODS

In a case-control study, BD patients (fulfilling the new International Criteria for BD) and controls (who had similar clinical symptoms but BD was clinically excluded in them) were included. Mean plasma homocysteine levels measured by enzyme-linked immunosorbent assay in HLA-B51 positive and negative individuals both in patients and controls were compared by t-test, Mann-Whitney test and analysis of variance (F-test).

RESULTS

Ninety-six BD patients and 152 controls were recruited. There was no significant difference between HLA-B51 positive and negative individuals either in the mean plasma homocysteine levels (13.59 ± 9.03 vs. 12.95 ± 4.98 μmol/L, P = 0.514), or in the prevalence of hyperhomocysteinemia (17% vs. 21.4%, P = 0.504). This was true both for BD and control groups. In HLA-B51 positive and negative BD patients, mean plasma homocysteine levels were 14.29 ± 12.02 and 12.62 ± 4.79 μmol/L, respectively (P = 0.33), and the prevalence of hyperhomocysteinemia was 20.8% versus 19.5% (P = 0.55). In the control group, the mean plasma homocysteine levels in HLA-B51 positive and negative individuals were 12.85 ± 4.28 and 13.14 ± 5.10 μmol/L, respectively (P = 0.794), and the prevalence of hyperhomocysteinemia was 13% versus 22.1% (P = 0.23). The difference was non-significant regarding sex (P > 0.71) and disease activity (P > 0.31).

CONCLUSION

In contrast to our previous report, we found no relationship between plasma homocysteine levels and HLA-B51 in this study, either in BD or in the control group.

Prevalence of LDL atherogenic phenotype in patients with systemic lupus erythematosus

BACKGROUND

Patients with systemic lupus erythematosus (SLE) are 5-8 times more likely to develop coronary heart disease than the general population. The aim of this study was to find out the prevalence of the small dense low-density lipoprotein (LDL) cholesterol particle in patients with SLE.

METHODS

We recruited 50 consecutive patients with SLE who had no evidence of hypertension or renal failure. Fifty age- and gender-matched healthy controls were also recruited. We measured serum lipid levels and LDL particle diameters by gradient gel electrophoresis in both patients and controls.

RESULTS

Patients with SLE had significant dyslipidemia, characterized by elevated plasma triglycerides, LDL cholesterol, Apoprotein B, triglyceride:high-density (HDL) lipoprotein cholesterol ratio, and decreased plasma concentrations of HDL cholesterol. The LDL particle size in SLE (24.8 ± 1.23 nm) was significantly (P < 0.01) smaller than that in controls (26.1 ± 1.31 nm). The prevalence of the LDL phenotype B (the atherogenic phenotype) was 52% in SLE but only 20% in healthy controls.

CONCLUSION

We conclude that the high prevalence of small dense LDL in SLE may contribute to the high incidence of coronary heart disease seen in this disorder.

Factors associated with arterial vascular events in PROFILE: a Multiethnic Lupus Cohort

The objective of this study was to determine the factors associated with the occurrence of arterial vascular events in a multiethnic systemic lupus erythematosus (SLE) cohort. The PROFILE cohort, comprised SLE patients (n = 1333) of defined ethnicity from five different US institutions, was studied to determine demographic, clinical and biological variables associated with vascular events. An arterial vascular event (first episode) was either a myocardial infarction, angina pectoris and/or a vascular procedure for myocardial infarction, stroke, claudication and/or evidence of gangrene. Patient characteristics were analyzed by univariable and multivariable Cox proportional hazards regression analyses. One-hundred twenty-three (9.8%) patients had at least one incident arterial event. Age at cohort enrollment (HR = 1.04, 95% CI 1.03-1.06), smoking (HR = 2.20, 95% CI 1.40-3.46) and the CRP2* C alleles (HR = 1.91, 95% CI 1.04-3.49) were associated with a shorter time-to-the occurrence of arterial vascular events. Some clinical manifestations of disease activity were associated with a shorter time-to-occurrence [psychosis (HR = 2.21, 95% CI 1.10-4.44), seizures (HR = 1.85, 95% CI 1.00-3.24) and anaemia (HR = 1.83, 95% CI 1.02-3.31)], but others were not [arthritis (HR = 0.32, 95% CI 0.18-0.58)]. In conclusion, older patients, especially in the context of a predisposing environmental factor (smoking) and severe clinical manifestations, are at higher risk of having arterial vascular events. The genetic contribution of the variation at the CRP locus was not obscured by demographic or clinical variables. Awareness of these factors should lead to more effective management strategies of patients at risk for arterial vascular events.

Determinants of risk for venous and arterial thrombosis in primary antiphospholipid syndrome and in antiphospholipid syndrome with systemic lupus erythematosus

OBJECTIVE

Antiphospholipid syndrome (APS) is characterized by thrombosis (venous and arterial) and pregnancy loss in conjunction with the lupus anticoagulant, IgG or IgM anticardiolipin, or IgG or IgM anti-beta2-glycoprotein I. In most series, only a minority of patients with antiphospholipid antibodies develop a clinical manifestation.

METHODS

A cross-sectional study of consecutive patients in the Hopkins Lupus Center was performed. Interviews were done and records were reviewed for the following variables: gender, ethnicity, hypertension, triglycerides, cholesterol, smoking, diabetes mellitus, homocysteine, cancer, hepatitis C, hormone replacement therapy/oral contraceptives, hereditary thrombophilia, anticardiolipin antibodies IgG, IgM and IgA, and lupus anticoagulant (LAC). Our aim was to identify risk factors associated with thrombosis and pregnancy loss in patients with antiphospholipid antibodies.

RESULTS

A total of 122 patients (84% female, 74% Caucasian) were studied. Patients were divided into 3 groups: primary APS, APS associated with systemic lupus erythematosus, and patients with systemic lupus erythematosus (SLE) with antiphospholipid antibodies but no thrombosis or pregnancy loss. Venous thrombosis was associated with high triglycerides (p=0.001), hereditary thrombophilia (p=0.02), anticardiolipin antibodies IgG>40 (p=0.04), and LAC (p=0.012). Hypertriglyceridemia was associated with a 6.4-fold increase, hereditary thrombophilia with a 7.3-fold increase, and anticardiolipin IgG>40 GPL with a 2.8-fold increase in the risk of venous thrombosis. Arterial thrombosis was associated with hypertension (p=0.008) and elevated homocysteine (p=0.044). Hypertension was associated with a 2.4-fold increase in the risk of arterial thrombosis. No correlations were found for pregnancy loss.

CONCLUSION

The frequency of thrombosis and pregnancy loss is greater in APS associated with SLE than in primary APS. Risk factors differ for venous and arterial thrombosis in APS. Treatment of hypertension may be the most important intervention to reduce arterial thrombosis. Elevated triglycerides are a major associate of venous thrombosis, but the benefit of treatment is not known. Hereditary thrombophilia is an associate of venous but not arterial thrombosis, making it cost-effective to investigate only in venous thrombosis.

New Clinical Syndromes in Dermatology

Dermatologists are in the unique position to be able to diagnose serious systemic diseases through skin findings; in addition, cutaneous manifestations can be associated with internal symptoms and clarify the pathogenesis and treatment of challenging new syndromes. Calciphylaxix, now renamed Calcific Uremic Arteriolopathy, primarily affects patients with end-stage renal disease with concomitant hyperphosphatemia, increased calcium-phosphate product and hyperparathyroidism, skin biopsy and wound care are crucial parts of the diagnosis and treatment. Hyperhomocysteinemia may play a very important role in many cutaneous and systemic diseases including, chronic cutaneous wounds, systemic lupus erythematosus, Behcet's disease and psoriasis. Through a skin biopsy and biochemical analysis of the proteoglycans accumulation it may be possible to diagnose a new systemic mucinosis and prevent sudden death in patients with severe mitral valve prolapse. Nephrogenic Fibrosing Dermopathy is a newly described fibrosing disorder occurring in patients with end stage renal disease, the etiology and pathogenesis are still unknown, and the ultimate course of this disease has not been defined.

A positive correlation between homocysteine and brachial–ankle pulse wave velocity in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is associated with premature atherothrombotic complications. Hyperhomocysteinemia is considered a cardiovascular risk factor. Increased vascular stiffness may increase cardiovascular mortality. Pulse wave velocity (PWV) is a noninvasive method of analyzing vascular stiffness in the assessment of atherosclerosis. The objective of this study was to identify the relationship between plasma homocysteine levels and brachial-ankle pulse wave velocity (baPWV) measurement in SLE. Plasma homocysteine, baPWV, ankle-brachial index, blood pressure, C3, C4, anticardiolipin antibody (aCL), and anti-double-stranded DNA antibodies were determined in a total of 58 female patients with SLE. The control group comprised 32 age-matched healthy females. In addition, all patients were further classified into subgroups according to the presence of aCL (SLE/aCL+, n=27 vs SLE/aCL-, n=31) to determine the effect of aCL on the tested variables. The mean values for plasma homocysteine and baPWV were 13.19 mumol/l and 1,482 cm/s, respectively. Plasma homocysteine levels were significantly elevated in SLE patients when compared with the healthy controls. SLE patients with aCL had a significantly higher plasma homocysteine level than those without aCL. A significant positive correlation between plasma homocysteine and baPWV was found in patients with SLE (r=0.335, P=0.028, n=58). Plasma homocysteine also significantly correlated with right baPWV in all SLE patients (r=0.371, P=0.014, n=58) and in the SLE/aCL+ group (r=0.523, P=0.031, n=27). These findings indicate a possible link between plasma homocysteine and baPWV in SLE. In conclusion, SLE patients had an increased level of plasma homocysteine, and this phenomenon appeared to be related to vascular stiffness.