Plasma homocysteine as a risk factor for atherothrombotic events in systemic lupus erythematosus

Association between serum uric acid and homocysteine levels among adults in the United States: a cross-sectional study

BACKGROUND

Many studies have shown that both elevated serum uric acid (SUA) levels and hyperhomocysteinemia are risk factors for atherosclerosis. However, the relationship between the two has not been thoroughly investigated.

OBJECTIVE

This study aimed to explore the possible link between SUA levels and homocysteine (Hcy) levels.

METHODS

In this cross-sectional study, 17,692 adults aged > 19 years in National Health and Nutrition Examination Survey from 1999 to 2006 were analyzed. Multivariable linear regression analysis was performed to assess the association between SUA and Hcy levels. In addition, smooth curve fitting (penalized spline method) and threshold effect analysis were performed.

RESULTS

Multivariable linear analysis showed that Hcy levels increased by 0.48 µmol/L (β = 0.48, 95%CI: 0.43-0.53) for every 1 mg/dL increase in SUA levels. We found a nonlinear relationship between SUA and Hcy levels. The results of threshold effect analysis showed that the inflection point for SUA levels was 7.1 mg/dL (β = 0.29, 95% CI: 0.23-0.36 and β = 1.05, 95% CI: 0.67-1.43 on the left and right sides of the inflection point, respectively). The p-values was less than 0.001 when using the log likelihood ratio test. This nonlinear relationship was also found in both sexes. The inflection point for SUA levels was 5.4 mg/dL in males and 7.3 mg/dL in females, respectively.

CONCLUSIONS

This cross-sectional study showed that the SUA levels were positively correlated with Hcy levels. And we found a nonlinear relationship between SUA and Hcy levels.

Arterial thrombosis triggered by methotrexate-induced hyperhomocysteinemia in a systemic lupus erythematosus patient with antiphospholipid antibodies

Systemic lupus erythematosus (SLE) patients have an increased risk of cardiovascular disease and thrombotic events, and the presence of antiphospholipid antibodies further raises the risk of these complications. Here we report a case of a patient with SLE and triple positivity for antiphospholipid antibodies who developed a popliteal artery thrombosis in the context of a severe hyperhomocysteinemia after the introduction of methotrexate (MTX) treatment. MTX is one of the most prescribed medications for a wide spectrum of autoimmune diseases, including SLE. On the other hand, by interfering with folate metabolism, it may induce hyperhomocysteinemia, which, in turn, may increase the risk of vascular complications. Current recommendations suggest screening and, when possible, treating classical and disease-related cardiovascular risk factors in all lupus patients. Based on what observed in our case, we suggest a follow-up of homocysteine levels after the introduction of drugs capable of inducing hyperhomocysteinemia, such as MTX, in SLE patients at high cardiovascular risk.

Antibodies against Phosphorylcholine-Implications for Chronic Inflammatory Diseases

Atherosclerosis and its main consequence, cardiovascular disease (CVD) are nowadays regarded as chronic inflammatory disease conditions, and CVD is the main cause of death in the world. Other examples of chronic inflammation are rheumatic and other autoimmune conditions, but also diabetes, obesity, and even osteoarthritis among others. In addition, infectious diseases can have traits in common with these conditions. Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease, where atherosclerosis is increased and the risk of CVD is very high. This is a clinical problem but could also shed light on the role of the immune system in atherosclerosis and CVD. Underlying mechanisms are of major interest and these are only partially known. Phosphorylcholine (PC) is a small lipid-related antigen, which is both a danger associated molecular pattern (DAMP), and a pathogen associated molecular pattern (PAMP). Antibodies against PC are ubiquitous and 5-10% of circulating IgM is IgM anti-PC. Anti-PC, especially IgM and IgG1 anti-PC, has been associated with protection in the chronic inflammatory conditions mentioned above, and develops during the first years of life, while being present at very low levels at birth. Animal experiments with immunization to raise anti-PC ameliorate atherosclerosis and other chronic inflammatory conditions. Potential mechanisms include anti-inflammatory, immune modulatory, clearance of dead cells and protection against infectious agents. An intriguing possibility is to raise anti-PC levels through immunization, to prevent and/or ameliorate chronic inflammation.

Systemic lupus erythematosus and cardiovascular disease

The prognosis in systemic lupus erythematosus (SLE) has improved due to better treatment and care, but cardiovascular disease (CVD) still remains an important clinical problem, since the risk of CVD in SLE is much higher than among controls. Atherosclerosis is the main cause of CVD in the general population, and in SLE, increased atherosclerosis, especially the prevalence of atherosclerotic plaques, has been demonstrated. Atherosclerosis is an inflammatory condition, where immunity plays an important role. Interestingly, oxidized low-density lipoprotein, defective clearance of dead cells, and inflammation, with a pro-inflammatory T-cell profile are characteristics of both atherosclerosis and SLE. In addition to atherosclerosis as an underlying cause of CVD in SLE, there are also other non-mutually exclusive mechanisms, and the most important of these are antiphospholipid antibodies (aPL) leading to the antiphospholipid antibody syndrome with both arterial and venous thrombosis. aPL can cause direct pro-inflammatory and prothrombotic effects on endothelial and other cells and also interfere with the coagulation, for example, by inhibiting annexin A5 from its antithrombotic and protective effects. Antibodies against phosphorylcholine (anti-PC) and other small lipid-related epitopes, sometimes called natural antibodies, are negatively associated with CVD and atherosclerosis in SLE. Taken together, a combination of traditional risk factors such as hypertension and dyslipidemia, and nontraditional ones, especially aPL, inflammation, and low anti-PC are implicated in the increased risk of CVD in SLE. Close monitoring of both traditional risk factors and nontraditional ones, including treatment of disease manifestations, not lest renal disease in SLE, is warranted.

Osteoprotegerin and MTHFR gene variations in rheumatoid arthritis: association with disease susceptibility and markers of subclinical atherosclerosis

We aimed to explore whether the rs2073618 variant (G1181C) of the osteoprotegerin (OPG) gene and the methylenetetrahydrofolate reductase (MTHFR) rs1801131 (A1298AC) and rs1801133 (C677T) gene polymorphisms contribute to rheumatoid arthritis (RA) susceptibility and RA related subclinical atherosclerosis. Overall 283 RA patients and 595 healthy controls (HC) were genotyped for common variants of the OPG and MTHFR genes using PCR based assays. Clinical and laboratory parameters were recorded following thorough chart review. Surrogate markers of subclinical atherosclerosis (Carotid/Femoral intima media thickness/plaque formation) along with traditional risk factors for atherosclerosis were assessed in all RA patients and 280HC. Increased prevalence of the CC genotype of the rs2073618 variant was detected in RA patients vs HC (42.4% vs. 33%, p-value: 0.04). RA patients with high serum titers of rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP) antibodies displayed increased prevalence of the CC genotype of the rs2073618 variant of the OPG gene compared to HC (48.6% and 47.5 vs 33.3%, p-values: 0.0029and 0.0077 respectively). Of interest, this genotype turned to be associated with higher carotid IMT scores (0.872 ± 0.264 vs 0.816 ± 0.284, p-value: 0.01) and marginally with higher rates of carotid plaque formation (66% vs 54.1%, p = 0.06). The MTHFR 1298CC genotype was more prevalent only in the anti-CCP positive group compared to HC, with no associations detected with markers of subclinical atherosclerosis, following adjustment for traditional cardiovascular (CVD) risk factors. Reduced rates of carotid/femoral plaque formation were detected among RA patients harboring the MTHFR TT genotype (52.4 vs 72.7, p-value: 0.009, respectively). This association remained significant following adjustment for classical CVD risk factors (OR [95% CI 0.364 [0.173–0.765], p-value: 0.008). Genetic variations of the osteoprotegerin and MTHFR genes seem to increase susceptibility for seropositive RA and potentially contribute to subclinical atherosclerosis linked to RA. Larger studies are needed to confirm these findings.

CRIF1 Deficiency Increased Homocysteine Production by Disrupting Dihydrofolate Reductase Expression in Vascular Endothelial Cells

Elevated plasma homocysteine levels can induce vascular endothelial dysfunction; however, the mechanisms regulating homocysteine metabolism in impaired endothelial cells are currently unclear. In this study, we deleted the essential mitoribosomal gene CR6 interacting factor 1 (CRIF1) in human umbilical vein endothelial cells (HUVECs) and mice to induce endothelial cell dysfunction; then, we monitored homocysteine accumulation. We found that CRIF1 downregulation caused significant increases in intracellular and plasma concentrations of homocysteine, which were associated with decreased levels of folate cycle intermediates such as 5-methyltetrahydrofolate (MTHF) and tetrahydrofolate (THF). Moreover, dihydrofolate reductase (DHFR), a key enzyme in folate-mediated metabolism, exhibited impaired activity and decreased protein expression in CRIF1 knockdown endothelial cells. Supplementation with folic acid did not restore DHFR expression levels or MTHF and homocysteine concentrations in endothelial cells with a CRIF1 deletion or DHFR knockdown. However, the overexpression of DHFR in CRIF1 knockdown endothelial cells resulted in decreased accumulation of homocysteine. Taken together, our findings suggest that CRIF1-deleted endothelial cells accumulated more homocysteine, compared with control cells; this was primarily mediated by the disruption of DHFR expression.

Loss of antiphospholipid antibody positivity post-thrombosis in SLE

Background/Purpose

Loss of positivity of antiphospholipid antibodies has been observed in clinical practice post-thrombosis in patients with SLE with secondary antiphospholipid syndrome (APS). Our study defined the frequency of this loss and the duration before positivity recurred.

Methods

In this prospective study, patients with SLE having at least two positive antiphospholipid markers prior to thrombosis and at least 1 year of follow-up after thrombosis were included. Antiphospholipid markers included lupus anticoagulant (dilute Russell viper venom test >45 s followed by mixing and confirmatory tests) and/or anticardiolipin titre (aCL IgG ≥20, aCL IgM ≥20 and/or aCL IgA ≥20). The percentage of visits with positive antiphospholipid markers after thrombosis was calculated. For patients with a negative antiphospholipid marker any time after thrombosis, survival estimates were performed to calculate the time to return of antiphospholipid positivity.

Results

In APS due to SLE, complete loss of antiphospholipid positivity post-thrombosis was up to 41% for aCL IgG, 51% for IgM and 50% for IgA, but only 20% for those with lupus anticoagulant. Of those who at some point lost aCL IgG or became negative for lupus anticoagulant, the majority (60% and 76%, respectively) reacquired the antibody within 5 years. In contrast, of those who lost aCL IgM or IgA, fewer reacquired it within 5 years (37% and 17%, respectively).

Conclusion

Intermittent positivity of antiphospholipid antibodies is present in APS due to SLE. These fluctuations make it difficult to decide on length of anticoagulation. Lupus anticoagulant is more likely to persist post-thrombosis.

Hyperhomocysteinemia and Ischemic Stroke: A Potential Dose-Response Association-A Systematic Review and Meta-analysis

Background and Purpose  Previous studies suggest an association between increased homocysteine (Hcy) and risk of ischemic stroke. Yet, it remains unknown whether a dose-response association exists between Hcy levels and risk of ischemic stroke. Methods  Systematic literature searches were performed in PubMed, Embase, Scopus, and Web of Science. Inclusion criteria were studies investigating ischemic stroke risk in an adult population with measured Hcy levels. We computed odds ratios (ORs) for a 5 µmol/L increase in Hcy levels using a random effects meta-analysis. Results  In total, 108 studies met the inclusion criteria of which 22 were rated as high-quality studies, and 20 studies included a dose-response analysis. Hcy levels were analyzed either as a continuous or categorical variable. The majority of the studies found an increased risk of ischemic stroke when comparing the highest-to-lowest Hcy strata. A graded association was observed over the Hcy strata, indicating a dose-response association, with the most apparent effect when Hcy levels exceeded approximately 15 µmol/L. No studies explored a potential nonlinear association between Hcy levels and ischemic stroke. Six studies were included in a meta-analysis, showing an OR of 1.43 (95% confidence interval [CI]: 1.28-1.61) per 5 µmol/L increase in Hcy levels. Conclusion  This review and meta-analysis indicate a dose-response association between Hcy levels and ischemic stroke. An evident increase in effect measures was observed when Hcy levels exceeded 15 µmol/L, indicating a nonlinear association between ischemic stroke and Hcy levels. This nonlinear association warrants further study. This study is registered with clinical trial ( https://www.crd.york.ac.uk/prospero/ ; unique identifier: CRD42019130371).

Intracellular homocysteine metabolites in SLE: plasma S-adenosylhomocysteine correlates with coronary plaque burden

Background and aims

We hypothesised that intracellular homocysteine and homocysteine metabolite levels in patients with SLE are disproportionately elevated compared with the levels seen in healthy subjects and that they are independently associated with coronary plaque in SLE.

Methods

A liquid chromatography–tandem mass spectrometry absolute quantification assay was used for the determination of six analytes in both plasma and peripheral blood mononuclear cells (PBMCs): homocysteine (Hcy), S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), methionine (Met), cystathionine (Cysta) and 5-methyltetrahydrofolate (5m-THF). We then compared intracellular (PBMC) and extracellular (plasma) Hcy and Hcy metabolite (SAM, SAH, Met, Cysta and 5m-THF) concentrations in 10 patients with SLE and in 10 age, sex and ethnicity matched controls. Subjects with a history of diabetes mellitus, cardiovascular disease, hypertension, alcohol consumption in excess of 3 units per day, anaemia, renal insufficiency (serum creatinine >1.5 mg/dL) and pregnancy were excluded. All patients with SLE had two coronary CT angiography studies as screening for occult coronary atherosclerotic disease.

Results

Plasma from patients with SLE had higher levels of Hcy (p<0.0001), SAH (p<0.05), SAM (p<0.001) and lower levels of Met (p<0.05) and Cysta (p<0.001) compared with controls. PBMC intracellular concentrations from patients with SLE had higher levels of Cysta (p<0.05), SAH (p<0.05), SAM (p<0.001) and lower levels of 5m-THF (p<0.001). Plasma SAH showed a positive correlation with total coronary plaque, calcified plaque and non-calcified plaque (p<0.05).

Conclusion

Intracellular concentrations of Hcy metabolites were significantly different between patients with SLE and controls, despite similar intracellular Hcy levels. Plasma SAH was positively correlated with total coronary plaque, calcified plaque and non-calcified plaque.

Plasma homocysteine levels are positively associated with interstitial lung disease in dermatomyositis patients with anti-aminoacyl-tRNA synthetase antibody

Homocysteine is a sulfhydryl-containing amino acid that is derived from dietary methionine, and there has been increasing evidence that elevated plasma homocysteine levels are associated with increased risk of central and peripheral vascular disorders, including carotid, coronary and peripheral arterial diseases, and Raynaud's phenomenon. Recently, associations of plasma homocysteine levels with autoimmune diseases such as systemic lupus erythematodes and systemic sclerosis have been reported. However, no study analyzed the association between plasma homocysteine levels and dermatomyositis (DM). The objective of this study was to examine plasma homocysteine levels and their clinical associations in patients with DM. Plasma homocysteine levels in 28 Japanese patients with DM and 22 healthy controls were examined. We found that the plasma homocysteine levels in DM patients were significantly higher than those in healthy individuals (15.8 ± 1.1 vs 8.5 ± 0.5 µmol/L, P < 0.01). Presence of mechanic's hand, complication of interstitial lung disease (ILD), high serum Krebs von den Lungen-6 (KL-6), surfactant protein-D and creatine kinase levels, and anti-aminoacyl-tRNA synthetase (ARS) antibody (Ab) positivity were significantly more prevalent among DM patients with elevated plasma homocysteine levels. The plasma homocysteine levels in DM patients with mechanic's hand, ILD and anti-ARS Ab were significantly higher than those in DM without those features. Furthermore, the plasma homocysteine levels were positively correlated with serum KL-6 levels. These results suggest that the pathogenesis of elevated plasma homocysteine levels may be associated with ILD in DM patients, especially with anti-ARS Ab, and further examination is required.

Imaging Pattern and Outcome of Stroke in Patients With Systemic Lupus Erythematosus: A Case-control Study

Objective

To evaluate the outcome of stroke in patients with systemic lupus erythematosus (SLE).

Methods

Patients who fulfilled ≥ 4 American College of Rheumatology criteria for SLE and had a history of stroke from 1997 to 2017 were identified. The functional outcome of stroke [assessed by the modified Rankin Scale (mRS) at 90 days], mortality, stroke complications, and recurrence were retrospectively studied and compared with matched non-SLE patients with stroke.

Results

Forty SLE patients and 120 non-SLE patients with stroke (age at stroke 44.7 ± 13.7 yrs, 87.5% women) were studied. Ischemic type of stroke (90% vs 63%, P = 0.001) and extensive infarction (69.4% vs 18.7%, P < 0.001) were more common in SLE than non-SLE patients. Border zone infarct and multiple infarcts on imaging were significantly more prevalent in SLE patients. Patients with SLE were more functionally dependent than controls at 90 days poststroke. Logistic regression showed that SLE was significantly associated with a poor stroke functional outcome independent of age, sex, past stroke, atherosclerotic risk factors, and the severity of stroke (OR 5.4, 95% CI 1.1–26.0, P = 0.035). Stroke mortality at 30 days was nonsignificantly higher in SLE than non-SLE patients, but all-cause mortality (37.5% compared to 8.3%, P < 0.001), recurrence of stroke (30% compared to 9.2%, P = 0.002), and poststroke seizure (22.5% compared to 3.3%, P = 0.001) were significantly more common in SLE patients after an observation of 8.4 ± 6.1 years. SLE was independently associated with all-cause mortality and stroke recurrence over time.

Conclusions

Stroke in patients with SLE is associated with a poorer outcome than matched controls in terms of functional recovery, recurrence, and mortality.

Investigation of the Association Between Carotid Artery Intima-Media Thickness (IMT) and Cardiac Risk Factors in Patients with Systemic Lupus Erythematosus

BACKGROUND

The relationship between SLE and traditional risk factors for cardiovascular events was evaluated.

METHODS

The data regarding sixty patients with SLE and 30 healthy controls (age and sex matched) were gathered using SLEDAI forms. Venous blood (10mL) from all the participants was examined for hs-CRP, homocysteine, VCAM1, CBC, anti-DNA antibody, C3, C4, low-density lipoprotein (LDL), cholesterol, FBS and triglyceride. The IMT of carotid arteries was determined bilaterally by ultrasound. Other measurements included insulin levels via Elisa (Linco/Millipore Corp) and the HOMA-IR index for insulin resistance.

RESULTS

The mean age (in years) in the test and control groups was 28.8±10.3 (18-52) and 33.8±9.13 (18-48), respectively. The average IMT in the test group was directly related to serum levels of VCAM1 (p<0.001), homocysteine (p<0.001), cholesterol (p<0.009), LDL (p<0.001), TG (p<0.001), and FPG (p=0.004). The association between other risk factors, insulin resistance, carotid IMT and SLEDAI, was nonexistent. Mean insulin and insulin resistance levels in all the participants were 0.43±2.06 µU/mL and 0.09±0.44, respectively. There was no significant difference between the test and control groups regarding serum insulin and insulin resistance levels (p=0.42 and p=0.9, respectively). None of the risk factors, such as hsCRP, VCAM1, or homocysteine, were shown to be related to insulin resistance (p=0.6, p=0.6, p=0.09, respectively).

CONCLUSION

Our findings did not show an increase in the prevalence of atherosclerosis in patients with SLE. There was no association between IMT and insulin resistance. However, the former was associated with FPG, total cholesterol, LDL, TG, homocystein and VCAM1.

Predisposing factors to nonfatal cardiovascular events in women with systemic lupus erythematosus. An observational, cross-sectional, multicenter study in Spain from the risk/systemic lupus erythematosus thematic network

Very few studies have been published on cardiovascular morbidity in Spanish patients diagnosed with systemic lupus erythematosus (SLE). Moreover, knowledge of the predictive factors for the occurrence of nonfatal events in this group of patients is scarce.This was a multicenter, observational, cross-sectional study designed to ascertain the prevalence of nonfatal cardiovascular risk factors and cardiovascular events (CVEs) in 335 Spanish women diagnosed with SLE between 2003 and 2013.The average patient age was 36.0 years (range: 26.4-45.6); 35 patients (10.7%) experienced at least 1 CVE, which most frequently affected the brain, followed by the heart, and finally, the peripheral vasculature. Both the number of admissions because of SLE (95% confidence interval [CI] odds ratio [OR] = 1.024-1.27, P = .017) and the systemic lupus international collaborating clinics (SLICC) chronicity index score (95% CI OR = 1.479-2.400, P = .000) resulted in an increase in the OR of these patients presenting a CVE. Regarding the classic risk factors, only the interaction between hypertension (HT) and treatment with antihypertensive drugs influenced the presence of CVEs (95% CI OR = 2.165-10.377, P = .000). The presence of a family history of early cardiovascular disease was also related to CVEs (95% CI OR = 2.355-40.544, P = .002). Binary logistic regression including the above factors resulted in a model in which the 3 main variables in each group persisted, implying that they must be independent of each other. However, the weight of the interaction between the family history of early cardiovascular disease and the interaction between HT and the use of antihypertensives was higher than for the number of admissions for SLE.The SLE disease activity over time (measured using the SLICC) and the number of hospital admissions due to the disease itself, both increase the risk of women with SLE presenting a CVE. Classic cardiovascular risk factors, especially HT and its treatment, as well as a family history of early CVEs, should be considered when assessing the risk of nonfatal CVEs in women with SLE.

Hyperhomocysteinemia and Lupus Nephritis

Background  In SLE, both disease-specific and traditional risk factors are important. Increased serum homocysteine levels are seen in approximately 15% of patients with systemic lupus erythematosus and are associated with an increased risk of atherothrombotic events in this population. The serum level of homocysteine in patients with lupus nephritis has not been well described. Methods We performed a retrospective review of patients who had both biopsy-proven lupus nephritis (class II-VI) and measured homocysteine levels during routine evaluation. Clinical and laboratory data were obtained from reviews of medical records. Results Of the 15 patients with lupus nephritis, 10 had elevated homocysteine levels. The ages ranged from 21-68 years and were predominately African-American females. There were three patients with class III, one with class III-V, two with class IV, and two with class V lupus nephritis. Two patients had more than one biopsy each, one with class III, IV-V, and one with III and IV. At the time, when the serum homocysteine level was measured, of the 10 patients with elevated homocysteine levels, five patients had positive anti-dsDNA, and four had hypocomplementemia predominately low C3 (three patients). All patients were on hydroxychloroquine. Conclusions  This study demonstrates that patients with lupus nephritis are at a higher risk (66.6%) for developing elevated homocysteine levels.

Systemic lupus erythematosus: Diagnosis and clinical management

Systemic lupus erythematosus (SLE) is a worldwide chronic autoimmune disease which may affect every organ and tissue. Genetic predisposition, environmental triggers, and the hormonal milieu, interplay in disease development and activity. Clinical manifestations and the pattern of organ involvement are widely heterogenous, reflecting the complex mosaic of disrupted molecular pathways converging into the SLE clinical phenotype. The SLE complex pathogenesis involves multiple cellular components of the innate and immune systems, presence of autoantibodies and immunocomplexes, engagement of the complement system, dysregulation of several cytokines including type I interferons, and disruption of the clearance of nucleic acids after cell death. Use of immunomodulators and immunosuppression has altered the natural course of SLE. In addition, morbidity and mortality in SLE not only derive from direct immune mediated tissue damage but also from SLE and treatment associated complications such as accelerated coronary artery disease and increased infection risk. Here, we review the diagnostic approach as well as the etiopathogenetic rationale and clinical evidence for the management of SLE. This includes 1) lifestyle changes such as avoidance of ultraviolet light; 2) prevention of comorbidities including coronary artery disease, osteoporosis, infections, and drug toxicities; 3) use of immunomodulators (i.e. hydroxychloroquine and vitamin D); and 4) immunosuppressants and targeted therapy. We also review new upcoming agents and regimens currently under study.

Homocysteine levels are independently associated with damage accrual in systemic lupus erythematosus patients from a Latin-American cohort

OBJECTIVE

To determine the impact of homocysteine levels on damage accrual in systemic lupus erythematosus (SLE) patients.

METHODS

This longitudinal study was conducted in consecutive patients seen every 6 months at our Rheumatology Department since 2012. Patients with available homocysteine levels and who had at least one subsequent visit were included. Univariable and multivariable Cox regression models were done to determine if homocysteine levels were predictive of damage accrual as per the SLICC Damage Index (SDI). The multivariable model was adjusted for pertinent variables (age at diagnosis, gender, socioeconomic status, disease duration, disease activity (SLEDAI), Framingham score, antimalarial and immunosuppressive drug use, average daily dose, and exposure time to prednisone (PDN)).

RESULTS

One hundred forty-five patients were included; their mean (SD) age at diagnosis was 43.70 (12.09) years, 136 (93.8%) were female, and nearly all were Mestizo. At baseline, disease duration was 7.55 (6.73) years; patients were followed for 3.54 (1.27) years. The SLEDAI was 5.60 (4.34), and the SDI 0.97 (1.35). The average daily PDN dose was 7.30 (5.78) mg/day and the time of PDN exposure was 7.36 (6.73) years. Mean homocysteine levels were 10.07 (3.71) μmol/L. The highest tertile of homocysteine levels predicted new damage accrual in the univariable and multivariable models [HR 1.78 (95% CI, 1.042-3.039); p = 0.035 and HR 2.045 (95% CI, 1.077-3.883); p = 0.029, respectively]. Increased levels (> 15 μmol/L) were found in 12 (8.3%) patients; 75 (51.7%) patients increased ≥ 1 SDI point.

CONCLUSION

In SLE patients, homocysteine levels predicted damage accrual independently of other well-known risk factors for such occurrence.

Possible Modulation of Vascular Function Measures in Rheumatoid Arthritis by Homocysteine

The effect of homocysteine on cardiovascular diseases is still equivocal, especially in rheumatoid arthritis patients. In this investigation, the association between homocysteine with blood flow and vascular resistance in rheumatoid arthritis was examined. Serum levels of homocysteine were determined in thirty-one rheumatoid arthritis patients and nineteen apparently healthy subjects using ELISA. Additionally, strain-gauge plethysmography was used to determine both forearm blood flow and vascular function at rest and after occlusion. Forearm occlusion blood flow (patients: 21.9 ± 6.55 versus control: 25.5 ± 6.10ml/100mL/min) was lower (p < 0.05) while occlusion vascular resistance (patients: 4.77 ± 2.08 versus controls 3.05 ± 0.96U) was greater (p < 0.01) in rheumatoid arthritis than in the controls. Level of serum homocysteine was similar (p = 0.803) in rheumatoid arthritis group and healthy group. In addition, level of serum homocysteine was correlated with resting blood flow (r = −0.41; p < 0.02) and resting vascular resistance (r = 0.31, p < 0.05) in the patients group. The study confirms altered vascular function in rheumatoid arthritis. Uniquely, the results show that homocysteine was related to resting, but not postischemia, vascular measures. These relationships indicate that homocysteine might impact the vasculature in rheumatoid arthritis.

Serum human epididymis protein 4 is a predictor for developing nephritis in patients with systemic lupus erythematosus: A prospective cohort study

BACKGROUND

It has been demonstrated that serum human epididymis protein 4 (HE4) is a useful biomarker for differentiating lupus nephritis (LN) from systemic lupus erythematosus (SLE). However, it remains unclear whether HE4 can be used to predict the development of LN.

METHODS

A total of 74 SLE patients without LN were recruited between August 2008 and September 2013. Serum HE4 concentrations were measured by enzyme-linked immunosorbent assay. These patients were followed up from the date of SLE diagnosis to LN development or the end of the study. The receiver operating characteristics (ROC) curve was drawn to assess the predictive value of HE4 for the incidence of LN. In addition, Kaplan-Meier and Cox regression analyses were used to determine the prognostic factors for the incidence of LN.

RESULTS

Serum HE4 levels significantly increased in patients who are positive for anti-dsDNA antibody, low C3 and the incidence LN (P < 0.05), and these were closely correlated with age, erythrocyte sedimentation rate (ESR) and the SLE disease activity index (SLEDAI) (P < 0.05). During the follow-up, 44 patients developed LN. The ROC curve revealed that for HE4 levels, the predictive performance for LN with 64.8 pM as an optimal cutoff yielded an AUC of 0.714, with a 95% confidence interval of 0.597-0.831, and a sensitivity and specificity of 81.8% and 53.3%, respectively. The Kaplan-Meier analysis revealed that LN occurred in 72% of high-HE4 patients and 33.3% of low-HE4 patients (P = 0.036). The univariate analysis revealed that anti-dsDNA antibody, low C3, SLEDAI and HE4 were significantly associated with the incidence of LN (P < 0.05). Multivariate Cox regression revealed that only SLEDAI and HE4 were independently associated with the incidence of LN.

CONCLUSION

Elevated serum HE4 is significantly associated with a higher risk of incidence for LN, and may be a useful predictor for developing LN.

Contribution of MTHFR gene variants in lupus related subclinical atherosclerosis

OBJECTIVE

Elevated concentrations of homocysteine have been previously identified as an independent risk factor for subclinical atherosclerosis in patients with systemic lupus erythematosus (SLE). Given that heightened homocysteine levels are known to be strongly influenced by genetic factors, in the current study we investigated the contribution of high homocysteine levels as well as of functional polymorphisms of the gene encoding for the enzyme 5, 10- methylenetetrahydrofolate reductase (MTHFR) to atherosclerotic disease characterizing SLE patients.

METHODS

Peripheral DNA samples from 150 SLE patients, 214 rheumatoid arthritis (RA) patients and 561 age/sex matched apparently healthy volunteers (HC) were genotyped by PCR-based assays for the detection of the MTHFR gene polymorphisms (c. 677C > T and c. 1298A > C). All SLE patients and 30 age sex matched RA patients underwent assessment for subclinical atherosclerosis [ultrasound measurement of intima-media thickness scores (IMT) and detection of carotid and/or femoral (C/F) plaque] and complete clinical and laboratory evaluation including serum homocysteine levels. Data were analyzed using univariate and multivariate models (SPSS 21.0).

RESULTS

Hyperhomocysteinemia was detected in 26.0% of SLE patients compared to 6.7% of age/sex matched RA controls (p = 0.02). Higher serum B12 levels and decreased frequency of the MTHFR 677TT variant in RA patients could potentially account for the observed differences between the groups. In SLE patients, both hyperhomocysteinemia and MTHFR 677TT genotype were identified as independent contributors for plaque formation, following adjustment for traditional cardiovascular risk factors and disease related features, including age, sex, BMI, cholesterol and triglyceride levels, presence of arterial hypertension, smoking (pack/years), disease duration and total steroid dose [OR 95% (CI): 5.8 (1.0-35.8) and 5.2 (1.1-24.0), respectively]. MTHFR 677TT genotype, but not hyperhomocysteinemia was also found to confer increased risk for arterial wall thickening, after the above confounders were taken into account [OR (95%) CI: 4.9 (1.2-20.6)].

CONCLUSIONS

Hyperhomocysteinemia and MTHFR 677TT genetic variant emerged as independent risk factors for subclinical atherosclerosis in SLE patients, implying genetic influences as potential contributors to the increased burden of atherosclerotic disease characterizing SLE.

Atherosclerosis in systemic lupus erythematosus

Cardiovascular disease (CVD), comprising coronary heart disease and stroke, is one of the most important causes of death in patients with systemic lupus erythematosus (SLE). The risks of developing both clinical CVD and sub-clinical atherosclerosis are increased in patients with SLE. This increase is not fully explained by traditional cardiovascular risk factors such as smoking, hypertension and elevated cholesterol, and it is believed that immune dysfunction also contributes to CVD risk in SLE. In particular, recent studies have shown that abnormalities in both serum lipid profile and the autoantibody and T lymphocyte response to lipids may play a role in development of atherosclerosis. The standard CVD risk calculation algorithms based on traditional risk factors underestimate the risk of developing CVD in patients with SLE. Thus, novel algorithms incorporating new biomarkers such as pro-inflammatory high-density lipoprotein and use of imaging techniques such as carotid ultrasound scanning may become increasingly valuable.

An update on diet and nutritional factors in systemic lupus erythematosus management

Systemic lupus erythematosus (SLE) is a chronic inflammatory and autoimmune disease characterised by multiple organ involvement and a large number of complications. SLE management remains complicated owing to the biological heterogeneity between patients and the lack of safe and specific targeted therapies. There is evidence that dietary factors can contribute to the geoepidemiology of autoimmune diseases such as SLE. Thus, diet therapy could be a promising approach in SLE owing to both its potential prophylactic effects, without the side effects of classical pharmacology, and its contribution to reducing co-morbidities and improving quality of life in patients with SLE. However, the question arises as to whether nutrients could ameliorate or exacerbate SLE and how they could modulate inflammation and immune function at a molecular level. The present review summarises preclinical and clinical experiences to provide the reader with an update of the positive and negative aspects of macro- and micronutrients and other nutritional factors, including dietary phenols, on SLE, focusing on the mechanisms of action involved.

Proposed Relationship Between Intravenous Immunoglobulin and Thrombosis in Renal Transplant Recipients

Objective:

To report 2 cases of intravenous human immunoglobulin (IVIG)–associated thrombosis in kidney transplant patients.

Case Summary:

Both cases involved female patients presenting to Henry Ford Hospital in Detroit for renal transplantation. Patient 1 presented with systemic lupus erythematosus, positive for both anticardiolipin and anti-DNA antibody. Patient 2, post nephrectomy, was found to have moderate hyperhomocysteinemia, with a total plasma homocysteine level of 3.9 mg/L. Both patients were considered highly sensitized and at high risk for rejection due to the presence of either high panel reactive antibody or a positive B cell flow cytometry crossmatch, in addition to other risk factors. Therefore, IVIG was considered a viable treatment option to be included in induction therapy. IVIG was administered both peri- and postoperatively, and both patients experienced immediate graft function with good urine output. Within 24 hours following transplantation, elevations in serum creatinine and decreases in urine output were seen. Subsequently, kidney exploration was performed and palpable thrombi in renal arteries and veins were detected. Immediate nephrectomy was performed in both cases.

Discussion:

Currently, evidence derived from case reports highlights numerous risk factors for IVIG-associated thrombosis, one of which appears to be a hypercoagulable state. It has also been reported that some IVIG products contain amounts of anticardiolipin antibodies; these antibodies may potentiate thrombosis in the presence of hypercoagulable states, such as hyperhomocysteinemia or antiphospholipid syndrome, in these 2 patients, the Naranjo probability scale indicated that there was a possible association between the thrombotic events and the use of IVIG.

Conclusions:

Prospective trials evaluating the safety of IVIG in highly sensitized transplant patients are scarce. Therefore, it is imperative that the benefits and risks be weighed when considering the use of IVIG in highly sensitized transplant patients.

Fractions of Total Plasma Homocysteine in Patients with Ischemic Stroke Before the Age of 55 Years

The mechanism responsible for the association between elevated circulating homocysteine levels and ischemic stroke remains unclear. Therefore, the authors assessed total plasma homocysteine (tHcy) and its fractions (free [fHcy] and protein-bound [bHcy] homocysteine) in patients with ischemic stroke before the age of 55 years. Fifty patients (23 men, mean age 46.8 ±7.6 years) with ischemic stroke or transient ischemic attacks, with symptoms lasting <72 hours were enrolled. In this group: 32 (64%) patients had hypertension; 12 (24%), ischemic heart disease (IHD); and 20 (40%), type 2 diabetes mellitus (DM). The control group consisted of 30 matched healthy individuals (17 men, mean age 44.6 ±6.2 years). The tHcy, fHcy, and bHcy levels were determined by high-performance liquid chromatography. tHcy and its fractions did not differ significantly between patients and controls. However, stroke patients with hypertension had significantly higher concentrations of tHcy and bHcy compared to stroke patients without hypertension (tHcy 13.0 ±3.3 vs 10.7 ±3.2 µmol/L, p<0.05; bHcy 9.7 ±2.6 vs 7.8 ±2.3 µmol/L, p<0.01, respectively); fHcy was borderline significant: 3.1 (1.5-6.5) vs 2.5 (1.8-5.3) µmol/L, p=0.05. The presence of IHD, DM, hyperlipoproteinemia, clinical subtypes of stroke, smoking, and family history of stroke did not influence these parameters. In the group of 50 patients, tHcy correlated with mean systolic blood pressure (BP) ( r =0.3, p<0.05) and bHcy correlated with mean systolic and mean diastolic BP ( r =0.3, p<0.05). These findings suggest an association between hypertension and redox status of Hcy in patients with ischemic stroke before the age of 55 years. This observation supports the hypothesis that elevated BP may contribute to Hcy-related vascular injury.

Hypercoagulable States

The hypercoagulable states consist of a group of prothrombotic clinical disorders associated with an increased risk for thromboembolic events. The abnormalities lead to inappropriate thrombus formation. After a review of the coagulation process, inherited disorders (including antithrombin-III deficiency, protein CS system deficiencies, disorders of plasmin generation, dysfibrinogenemias, and homocysteinuria) and acquired disorders (including responses to surgery, cancer, drugs, and the antiphospholipid syndrome) are described. Screening and management methods are discussed. Copyright © 1997 by W. B. Saunders Company.

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.

Association of brachial-ankle pulse wave velocity with cardiovascular risk factors in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is associated with premature atherosclerosis. Increasing arterial stiffness is closely associated with atherosclerotic cardiovascular diseases, and pulse wave velocity (PWV) is considered to be an indicator of arterial stiffness. The objective of this study was to identify the relationship between brachial-ankle pulse wave velocity (baPWV) and cardiovascular risk factors in patients with SLE. Age, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBS), plasma lipid profile, plasma homocysteine, thiobarbituric acid reactive substances (TBARS), baPWV, ankle-brachial index (ABI), and SLE-related factors were determined in a total of 83 SLE patients (12 males and 71 females). All SLE patients were further classified into two subgroups according to baPWV value (baPWV 1400 cm/s, n 37 versus baPWV 1400 cm/s, n 46). The mean baPWV value of studied SLE patients was 1520 381 cm/s. Age, BMI, SBP, DBP, FBS, TBARS and homocysteine levels were significantly higher in SLE patients with baPWV value 1400 cm/s than in SLE patients with baPWV value 1400 cm/s. In addition, baPWV correlated significantly with age, SBP, DBP, FBS and homocysteine. Moreover, stepwise multiple regression analysis showed that age and SBP were independently associated with baPWV. The results of this study indicate a possible link between vascular stiffness measured by baPWV and cardiovascular risk factors in patients with SLE.

Lack of subclinical myocardial ischaemia in Mexican patients with systemic lupus erythematosus without traditional risk factors for coronary artery disease

The objective of this study was to analyse whether patients with systemic lupus erythematosus (SLE) without traditional risk factors for coronary artery disease (CAD) develop subclinical myocardial ischaemia in the first years after diagnosis. A cross-sectional analysis of a cohort of 200 female SLE patients was conducted. We selected those patients who fulfilled the American College of Rheumatology (ACR) SLE criteria and had no traditional risk factors for CAD, including diabetes mellitus, hypertension, obesity, hyperlipidemia, and smoking. After an initial clinical and laboratory examination, patients were evaluated using a baseline echocardiogram and a dobutamine and atropine stress echocardiogram to search for subclinical myocardial ischaemia. Forty-one patients were included in the study. The mean age at the time of the study was 34.5 ± 9.56 years (mean ± SD). The mean age at diagnosis was 30.3 ± 9.39 years. The mean time from diagnosis was 3.9 ± 3.3 years. Baseline disease activity index (MEX-SLEDAI score) showed that 92.6% of patients had disease activity, although most patients had mild activity. A dobutamine and atropine stress echocardiogram was performed in 40 patients. All 40 patients had negative tests for subclinical myocardial ischaemia. Patients without traditional risk factors for CAD do not have an increased risk for subclinical myocardial ischaemia in the first years after diagnosis. A longitudinal follow-up study of these patients is needed to confirm our findings and assess if additional non-traditional risk factors for CAD increase the risk for myocardial ischaemia. Lupus (2007) 16, 298—301.

Cardiac involvement in systemic lupus erythematosus

Pericarditis is the most common cardiac abnormality in systemic lupus erythematosus (SLE) patients, but lesions of the valves, myocardium and coronary vessels may all occur. In the past, cardiac manifestations were severe and life threatening, often leading to death. Therefore, they were frequently found in post-mortem examinations. Nowadays cardiac manifestations are often mild and asymptomatic. However, they can be frequently recognized by echocardiography and other noninvasive tests. Echocardiography is a sensitive and specific technique in detecting cardiac abnormalities, particularly mild pericarditis, valvular lesions and myocardial dysfunction. Therefore, echocardiography should be performed periodically in SLE patients. Vascular occlusion, including coronary arteries, may develop due to vasculitis, premature atherosclerosis or antiphospholipid antibodies associated with SLE. Premature atherosclerosis is the most frequent cause of coronary artery disease (CAD) in SLE patients. Efforts should be made to control traditional risk factors as well as all other factors which could contribute to atherosclerotic plaque development.

Successful long-term treatment of systemic lupus erythematosus with rituximab maintenance therapy

Systemic lupus erythematosus(SLE) is a chronic, inflammatory autoimmune disease that may involve multiple organ systems. Treatment consists of immunosuppression, cytotoxic treatment, plasmapheresis and immunoglobuline therapy. Treatment of patients refractory to standard treatment approaches is difficult and results are poor. We describe a 39-year old patient with SLE sufferingfrom grand mal epilepsy due to cerebralvasculopathywith positivelupus anticoagulant, who was refractory to standard treatment modalities. The patient was treated with the anti-CD20 monoclonal antibody rituximab (375 mg/m2 ×4, repeated at weekly intervals). Rituximab applications were delivered in October 2000, March 2001 and October 2001. Since March 2002 she has received maintenance therapy with rituximab 375 mg/m2 every three months. A second female with refractory SLE was treated successfully in April 2002 and receives maintenance therapy every three months. Both patients responded well to rituximab therapy. The first patient showed a major improvement of her clinical condition, and 30 months after the beginning of the rituximab therapy she is free of any symptoms. inflammation parameters, ANA and lupus anticoagulantdeclined significantly after the treatment. The clinical conditionof the second patient improved dramatically, all inflammation parameters normalized and her circulating immunocomplexes disappeared. In conclusion, rituximab maintenance treatment may be a new effective therapy in SLE.

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.

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

Cardiovascular disease is a major cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Antiphospholipid syndrome (APS) is one of the most important causes of thrombosis in SLE. In addition, an association between hyperhomocysteinemia and increased cardiovascular risk has also been reported. Our aim is to analyse the association of thrombosis with plasma total homocysteine (ptHcy), antiphospholipid antibodies (aPL) and other vascular risk factors in SLE patients. Fasting plasma levels of ptHcy, vitamin B12, folate, total cholesterol and creatinine were measured in 117 SLE patients. Clinical and immunological data were obtained from our prospective computerized database. aPL-positivity was defined according to Sapporo criteria. There was no association between aPL and ptHcy. ptHcy was higher in patients with arterial (median 13.02 versus 10.16 mmol/L, P = 0.010) but not venous thrombosis. In the subgroup analysis, this association was only seen in aPL-negative patients. In logistic regression, aPL (OR 6.60, 95% CI 1.86-23.34) and ptHcy (OR 1.10, 95% CI 1.01-1.19) were independently associated with arterial thrombosis. However, when hypertension, smoking and plasma total cholesterol were added to the model, only aPL (OR 7.38, 95% CI 2.02-26.91) and hypertension (OR 7.70, 95% CI 2.33-25.39), but not ptHcy, remained independently related to arterial events. aPL was the only variable independently related to venous thrombosis (OR 7.68, 95% CI 1.60-36.86). ptHcy concentrations are higher in SLE patients with arterial thrombosis. No interaction between homocysteine and aPL was found. Raised ptHcy may be a marker of increased vascular risk in aPL-negative SLE patients. The role of homocysteine as a marker of vascular risk may depend on the presence of traditional risk factors, although a modest intrinsic effect cannot be entirely excluded.

Hyperhomocysteinemia and Venous Thrombosis

Deep vein thrombosis (DVT) leads to venous ulcers in later life. Venous ulcers are the majority of chronic lower extremity wounds. Recent evidence suggests that hyperhomocysteinemia is an independent risk factor for venous thrombosis. Other evidence suggests that dietary supplementation with folic acids and vitamins helps to change hyper-homocysteinemia. This may be the key to wound management in the future.

Assessment of the independent associations of IgG, IgM and IgA isotypes of anticardiolipin with thrombosis in SLE

Objective

The Sydney classification criteria for antiphospholipid syndrome include lupus anticoagulant or moderate-to-high titre anticardiolipin IgG or IgM. We explored the association of all anticardiolipin isotypes, lupus anticoagulant and the combination with venous and arterial thrombosis.

Methods

Patients with systemic lupus erythematosus (SLE) in a large clinical cohort seen quarterly were repeatedly tested by protocol for anticardiolipin antibodies and lupus anticoagulant. Subgroups of patients were defined based on the geometric mean titres of IgG, IgM, IgA anticardiolipin and lupus anticoagulant expressed in dilute Russell's viper venom time (RVVT) seconds for each patient across all cohort visits. These subgroups were compared with respect rates of thrombosis since diagnosis with SLE. Rate ratios were estimated using Cox Proportional Hazards models.

Results

Of the 1390 cohort members included, there were 284 thrombotic events observed over 17 025 person-years since diagnosis for a rate of 1.7 events per 100 person-years. Those with a geometric mean titre of IgG anticardiolipin >20 had a significantly elevated rate of thromboses (rate ratio 1.8, p=0.0052), whereas there was no evidence of an association between thromboses and elevated IgM geometric mean (rate ratio 1.2, p=0.40). There were relatively few cohort members with elevated IgA geometric mean but the rate of thromboses in that group was elevated (rate ratio 1.7, p=0.23). The associations between anticardiolipin antibodies and thromboses were strongest when considering venous thromboses. Those with two or more elevated anticardiolipin isotypes or those with both IgG anticardiolipin and RVVT did not appear at higher risk than those with a single elevated marker.

Conclusion

This study supports previous observations that IgG anticardiolipin and lupus anticoagulant are associated with higher rates of thromboses. Our power to study IgA anticardiolipin was limited due to small number of patients with elevated IgA.

Apolipoprotein-containing lipoprotein subclasses and subclinical atherosclerosis in systemic lupus erythematosus

OBJECTIVE

Traditional classification of hyperlipidemia using high-density lipoprotein, low-density lipoprotein (LDL), and very low-density lipoprotein does not provide information on lipoprotein function. Apolipoproteins (Apos), which are protein components of plasma lipoproteins (including A, B, C, D, E) with their different composition, metabolic, and atherogenic properties, provide insight on lipoprotein functioning. In particular, the Apo B/A-I ratio is associated with atherogenic LDL and development of cardiovascular disease. We explored the baseline association between these nontraditional risk factors with subclinical measures of atherosclerosis (coronary artery calcification [CAC] and carotid intima-media thickness [IMT]) in systemic lupus erythematosus (SLE).

METHODS

A total of 58 SLE patients (97% women, 58% white, 40% African American, and 2% other, mean ± SD age 44 ± 11 years) had measurement of Apo and lipoproteins by immunoturbidimetric procedures, electroimmunoassays, and immunoprecipitation. CAC was measured by helical computed tomography and carotid IMT by carotid duplex. This study was based on the baseline assessment of subclinical atherosclerosis in the Lupus Atherosclerosis Prevention Study. The measurement of the lipoproteins was made on sera collected at the same time.

RESULTS

There was no association between cardioprotective Apos (Apo A-I, LpA-I, LpA-I:A-II) and CAC (P < 0.15, P < 0.41, and P < 0.39, respectively) or carotid IMT (P < 0.97, P < 0.53, and P < 0.76, respectively). CAC and carotid IMT did not associate with atherogenic Apos either, including LpB:E+LpB:C:E, Apo B, LpB, LpB:C, Apo C-III, Apo C-III-HS, Apo C-III-HP, Apo C-III-R, LpA-II:B:C:D:E, and Apo B/Apo A-I. Measures of disease activity, including physician's global assessment and Systemic Lupus Erythematosus Disease Activity Index, were not associated with CAC or carotid IMT.

CONCLUSION

Neither cardioprotective nor atherogenic lipoproteins were associated with measures of subclinical atherosclerosis in this series of SLE patients. Further studies with a larger sample size are warranted to confirm our findings.

Relationship between homocysteine levels and hypertension in systemic lupus erythematosus

OBJECTIVE

Homocysteine has been linked to atherosclerosis and hypertension (HT) in the general population. However, there is limited evidence regarding the effect of homocysteine on blood pressure and arterial stiffness in systemic lupus erythematosus (SLE). We examined whether homocysteine is associated with HT and arterial stiffness in women with SLE.

METHODS

In total, 99 women with SLE without a history of cardiovascular disease or diabetes mellitus and 101 matched controls were included in this cross-sectional study. Participants were analyzed for homocysteine levels, cardiovascular risk factors, and arterial stiffness assessed by means of carotid-femoral pulse wave velocity (PWV). Associations between homocysteine, systolic blood pressure (SBP), PWV, and HT were tested using univariate and multivariate analyses.

RESULTS

Homocysteine levels (mean ± SD 12.3 ± 4.8 versus 9.3 ± 3.8 μmoles/liter), PWV (mean ± SD 7.54 ± 1.1 versus 7.10 ± 1.1 meters/second), SBP (mean ± SD 119 ± 13 versus 115 ± 12 mm Hg), and the prevalence of hyperhomocysteinemia (23% versus 7%) and HT (43% versus 12%) were significantly higher in women with SLE (P < 0.050 for all). In the univariate analysis, homocysteine correlated positively with SBP (P = 0.001) and PWV (P = 0.023) in women with SLE but not in controls. In the multiple linear regression analysis, SBP was independently associated with homocysteine and body mass index (BMI) in women with SLE. Similarly, in the multivariate logistic regression analysis, homocysteine levels (or hyperhomocysteinemia), BMI, and daily prednisone dose were independently associated with HT in women with SLE.

CONCLUSION

Homocysteine was independently associated with SBP and HT in women with SLE, but not in controls. Elevated homocysteine levels could increase the risk of HT in SLE.

Microembolic Signals in Patients with Systemic Lupus Erythematosus

Introduction:

Central nervous system (CNS) involvement is a common and less understood aspect of systemic lupus erythematosus (SLE). Microembolic signals (MES) have been reported in SLE. We conducted a prospective study to evaluate the frequency of MES among patients with CNS involvement and those without. The main aim of the study is to clarify the pathophysiology of the CNS involvement in SLE.

Methods and Materials:

Sixty eight patients with a diagnosis of SLE (60 females, 8 males) participated in the study. Both middle cerebral arteries were monitored using transcranial Doppler for 60 min to detect MES. All cases underwent neurology and psychiatry assessments.

Results:

MES were detected in 7/68 patients (10.3%) with the mean number of 3.5 per hour. MES were significantly higher in patients with CNS involvement (6/24, 25%) than those without (1/44, 2.2%) (P=0.006). SLE disease activity index, duration of disease, plaque formation, intima-media thickness, and antiphospholipid antibodies were not associated with MES. MES were more frequent in patients receiving Aspirin and/or Warfarin (p=0.02).

Conclusions:

MES may be a predictor for CNS involvement in SLE patients at risk for neuropsychiatric syndromes. Cerebral embolism may be implicated in the pathophysiology of neuropsychiatric SLE.

[Atherosclerosis in systemic lupus erythematosus]

CONTEXT

Evidence from epidemiological studies demonstrates that patients with systemic lupus erythematosus (SLE) are at increased risk for the development of cardiovascular disease. Traditional cardiovascular risk factors' play an important role in this phenomenon but do not account for the entire risk in lupus patients.

OBJECTIVES

The incidence and prevalence of cardiovascular events and infraclinical atherosclerosis are reviewed. Combinations of traditional risk factors with lupus-specific and treatment-related variables are detailed.

RESULTS

Atherosclerosis is more prevalent and occurs prematurely in lupus patients. Relative risk of myocardial infarction is between 5 to 8 times greater that of general population, and may exceed 50 in women between 35 and 44 years old. SLE was also found as an independent risk factor for subclinical atherosclerosis, and more than one third of lupus patient show evidence of carotid plaques of coronary artery calcifications. Lupus patients have more frequent traditional risk factors compared with general population of similar age and sex. Besides the traditional risk factors, SLE specific risk factors have been identified among witch advanced age at diagnosis, current disease activity, duration of the disease and renal activity. Moreover, lipid abnormalities in patients with SLE are common and likely are one of the major causes of premature atherosclerosis in these patients; the dyslipoprotein associated increased triglycerides and depressed HDL-cholesterol with proinflammatory HDL production. Autoimmunity may have a part of responsibility, but data's in favour of this hypothesis are not strong. Other mechanisms such as vascular inflammation, oxidative stress, immune complexes and complement activation may also elicit endothelial damage and promote atherosclerosis are associated with the pathogenesis of both SLE and atherosclerosis. Steroids may have a true double-edged role with a pro-atherogenic risk regarding the exacerbation of metabolic risk factors and a "beneficial" anti-inflammatory role. It is becoming increasingly apparent that antimalarials treatment in SLE has an atheroprotective and a cardioprotective effect. The other immunosuppressive drugs may reduce progression of atherosclerosis and cardiovascular events but their precise role remains to be elucidated. Despite their role in primary prevention in target general population, for now, systematic prescription of statins does not show a great benefit in the cardiovascular risk in lupus patients.

CONCLUSION

Mechanisms of atherosclerosis in SLE remain elusive. It is partially explained by the interaction of traditional cardiovascular risk factors, lupus-specific factors and therapy specially corticosteroids. Management strategies of lupus should include early all those items.

Elevated serum homocysteine levels were not correlated with serum uric acid levels, but with decreased renal function in gouty patients

Hyperhomocysteinemia is one of the important factors of the cardiovascular disease, and gout is well known to be associated with cardiovascular disease. There are a few reports on the serum homocysteine (Hcy) levels in patients with gout, however, the results showed discrepancies. In this study, we measured Hcy levels in patients with gout and examined factors associated with the levels of serum Hcy. Ninety-one male patients with gout and 97 age-matched healthy male controls were enrolled in the study. Serum uric acid levels were not significantly different between gout and healthy control groups. However, serum Hcy levels were significantly higher in patients with gout compared to controls (13.96 ± 4.05 µM/L vs 12.67 ± 3.52 µM/L, P=0.035). In gout group, patients with 1-2 stages of chronic kidney disease (CKD) had significantly lower serum Hcy than those with 3-5 stages of CKD (13.15 ± 3.46 µM/L vs 17.45 ± 4.68 µM/L, P<0.001). Multivariate linear analysis revealed an inverse association between serum Hcy and estimated glomerular filtration rate (eGFR) (β=-0.107, P<0.001). In conclusion, serum Hcy was elevated in male patients with gout. Hyperhomocysteinemia was not correlated with serum uric acid, but it was inversely associated with impaired renal function.

Prevention and management of co-morbidities in SLE

The prognosis and survival of patients with systemic lupus erythematosus (SLE) have improved over the past few decades. The major cause of death is no longer active lupus, but instead cardiovascular disease, complications of renal failure, and malignancy. Co-morbid factors, including both traditional and non-traditional cardiovascular risk factors, can be targeted according to accepted guidelines. We will emphasize the deleterious effect of corticosteroids in contributing to cardiovascular risk and the need to shift maintenance prednisone doses to a much lower threshold.

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.

Effects of methionine synthase and methylenetetrahydrofolate reductase gene polymorphisms on markers of one-carbon metabolism

Genetic and nutritional factors play a role in determining the functionality of the one-carbon (1C) metabolism cycle, a network of biochemical reactions critical to intracellular processes. Genes encoding enzymes for methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MTR) may determine biomarkers of the cycle including homocysteine (HCY), S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH). MTHFR C677T is an established genetic determinant of HCY but less is known of its effect on SAM and SAH. Conversely, the relationship between MTR A2756G and HCY remains inconclusive, and its effect on SAM and SAH has only been previously investigated in a female-specific population. Folate and vitamin B12 are essential substrate and cofactor of 1C metabolism; thus, consideration of gene-nutrient interactions may clarify the role of genetic determinants of HCY, SAM and SAH. This cross-sectional study included 570 healthy volunteers from Kingston, Ontario, Ottawa, Ontario and Halifax, Nova Scotia, Canada. Least squares regression was used to examine the effects of MTR and MTHFR polymorphisms on plasma HCY, SAM and SAH concentrations; gene-gene and gene-nutrient interactions were considered with the inclusion of cross-products in the model. Main effects of MTR and MTHFR polymorphisms on HCY concentrations were observed; however, no gene-gene or gene-nutrient interactions were found. No association was observed for SAM. For SAH, interactions between MTR and MTHFR polymorphisms, and MTHFR polymorphism and serum folate were found. The findings of this research provide evidence that HCY and SAH, biomarkers of 1C metabolism, are influenced by genetic and nutritional factors and their interactions.

Transient ischemic attack and stroke in systemic lupus erythematosus

Ischemic stroke is increased in systemic lupus erythematosus (SLE) patients. The differential diagnosis of stroke in SLE is complex. Transient ischemic attack and ischemic stroke share pathophysiologic mechanisms, but prognosis may vary depending on severity and cause, and definitions are dependent on the timing and extent of the diagnostic evaluation. In SLE patients with a history of transient ischemic attacks, stroke occurred in 57%. Cerebrovascular events account for 20% to 30% of deaths in patients with SLE. In SLE, both disease-specific and traditional stroke risk factors are important.