Cell adhesion molecules as potential biomarkers of nephritis, damage and accelerated atherosclerosis in patients with SLE

Endothelial cell activation and glycocalyx shedding - potential as biomarkers in patients with lupus nephritis

Lupus nephritis (LN) is a common and severe manifestation of systemic lupus erythematosus and an important cause of acute and chronic kidney injury. Early diagnosis of LN and preventing relapses are key to preserving renal reserve. However, due to the complexity and heterogeneity of the disease, clinical management remains challenging. Kidney biopsy remains the gold standard for confirming the diagnosis of LN and subsequent assessment of kidney histopathology, but it is invasive and cannot be repeated frequently. Current clinical indicators of kidney function such as proteinuria and serum creatinine level are non-specific and do not accurately reflect histopathological changes, while anti-dsDNA antibody and C3 levels reflect immunological status but not kidney injury. Identification of novel and specific biomarkers for LN is prerequisite to improve management. Renal function deterioration is associated with changes in the endothelial glycocalyx, a delicate gel-like layer located at the interface between the endothelium and bloodstream. Inflammation induces endothelial cell activation and shedding of glycocalyx constituents into the circulation. This review discusses the potential role of soluble glycocalyx components as biomarkers of active LN, especially in patients in whom conventional serological and biochemical markers do not appear helpful.

B-cell activating factor and A proliferation-inducing ligand in relation to intima-media thickness as biomarkers of premature atherosclerosis in systemic lupus erythematosus patients

BACKGROUND

The aim of this study was to assess the correlation of the serum B-cell activating factor (BAFF), A proliferation-inducing ligand (APRIL) and interleukin (IL)-21 with carotid intima-media thickness (cIMT) to evaluate their efficacy as non-invasive biomarkers for the risk of premature development of atherosclerosis.

METHODS

ELISA test was used to quantify serum BAFF, APRIL and IL-21 in 40 patients with systemic lupus erythematosus (SLE) and 20 healthy controls (HCs). The obtained results were correlated with disease duration, anti-double stranded DNA, complement proteins levels, lipid profile, cIMT and the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI).

RESULTS

Serum BAFF, APRIL and IL-21 were significantly increased in SLE compared to HCs. Positive correlation was recorded between BAFF (r = 0.51) and APRIL (r = 0.52) with the cIMT. IL-21 correlated positively with SLEDAI (r = 0.33) and negatively with BAFF (r = -0.37) and APRIL (r = -0.44). According to the multiple logistic regression analysis, we found that low-density lipoprotein, serum BAFF and APRIL values were independent factors for cIMT in SLE. To discriminate premature atherosclerosis in patients with SLE, BAFF ≥455 pg/ml yielded 88.9% sensitivity with 100% specificity while APRIL ≥600 pg/ml yielded 95% sensitivity with 100% specificity. IL-21 ≥240 pg/ml yielded 66.7% sensitivity and 100% specificity.

CONCLUSIONS

Circulating BAFF and APRIL in patients with SLE were correlated to disease activity and cIMT, suggesting that they could be used as a peripheral blood biomarker for the occurrence of premature atherosclerosis in SLE.

Diagnostic test accuracy of novel biomarkers for lupus nephritis-An overview of systematic reviews

INTRODUCTION

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with multiorgan inflammatory involvement and a mortality rate that is 2.6-fold higher than individuals of the same age and sex in the general population. Approximately 50% of patients with SLE develop renal impairment (lupus nephritis). Delayed diagnosis of lupus nephritis is associated with a higher risk of progression to end-stage renal disease, the need for replacement therapy, and mortality. The initial clinical manifestations of lupus nephritis are often discrete or absent and are usually detected through complementary tests. Although widely used in clinical practice, their accuracy is limited. A great scientific effort has been exerted towards searching for new, more sensitive, and specific biomarkers in recent years. Some systematic reviews have individually evaluated new serum and urinary biomarkers tested in patients with lupus nephritis. This overview aimed to summarize systematic reviews on the accuracy of novel serum and urinary biomarkers for diagnosing lupus nephritis in patients with SLE, discussing how our results can guide the clinical management of the disease and the direction of research in this area.

METHODS

The research question is "What is the accuracy of the new serum and urinary biomarkers studied for the diagnosis of LN in patients with SLE?". We searched for systematic reviews of observational studies evaluating the diagnostic accuracy of new serum or urinary biomarkers of lupus nephritis. The following databases were included: PubMed, EMBASE, BIREME/LILACS, Scopus, Web of Science, and Cochrane, including gray literature found via Google Scholar and PROQUEST. Two authors assessed the reviews for inclusion, data extraction, and assessment of the risk of bias (ROBIS tool).

RESULTS

Ten SRs on the diagnostic accuracy of new serum and urinary BMs in LN were selected. The SRs evaluated 7 distinct BMs: (a) antibodies (anti-Sm, anti-RNP, and anti-C1q), (b) cytokines (TWEAK and MCP-1), (c) a chemokine (IP-10), and (d) an acute phase glycoprotein (NGAL), in a total of 20 review arms (9 that analyzed serum BMs, and 12 that analyzed BMs in urine). The population evaluated in the primary studies was predominantly adults. Two SRs included strictly adults, 5 reviews also included studies in the paediatric population, and 4 did not report the age groups. The results of the evaluation with the ROBIS tool showed that most of the reviews had a low overall risk of bias.

CONCLUSIONS

There are 10 SRs of evidence relating to the diagnostic accuracy of serum and urinary biomarkers for lupus nephritis. Among the BMs evaluated, anti-C1q, urinary MCP-1, TWEAK, and NGAL stood out, highlighting the need for additional research, especially on LN diagnostic panels, and attempting to address methodological issues within diagnostic accuracy research. This would allow for a better understanding of their usefulness and possibly validate their clinical use in the future.

REGISTRATION

This project is registered on the International Prospective Registry of Systematic Reviews (PROSPERO) database (CRD42020196693).

Can Micro RNA-24 Affect the Cardiovascular Morbidity in Systemic Lupus Erythematosus by Targeting YKL-40?

Background

Systemic lupus erythematosus (SLE) is an autoimmune disease with inflammatory nature. One of the leading causes of death in SLE patients is cardiovascular (CVS) morbidity. MiRNA-24 is highly expressed in vascular endothelial cells (VECs). This dysregulated expression pattern is associated with dysfunction or even damage of VECs and leads to the occurrence of cardiovascular diseases. YKL- 40 is an inflammatory glycoprotein involved in the pathogenesis of endothelial dysfunction and thereby atherosclerosis. In this work, we aimed at illustrating the possible role of miR-24 and its target YKL-40 in the pathogenesis of the CVS morbidity associated with SLE.

Methods

This work was conducted on 40 SLE patients and 40 healthy controls. Quantitative real-time PCR (qPCR) was done to estimate the expression level of miRNA-24 in serum. In addition, we measured the serum level of YKL-40 using ELISA.

Results

miR-24-fold change was found to be down-regulated, whereas serum YKL- 40 was up-regulated among SLE patients with observed significant and negative correlation between the two parameters.

Conclusion

Our study provided an insight about the role of miR-24 and its target serum YKL-40 protein in the development of SLE-related inflammation and atherosclerosis.

Emerging Molecular Markers Towards Potential Diagnostic Panels for Lupus

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease which can affect various tissues and organs, posing significant challenges for clinical diagnosis and treatment. The etiology of SLE is highly complex with contributions from environmental factors, stochastic factors as well as genetic susceptibility. The current criteria for diagnosing SLE is based primarily on a combination of clinical presentations and traditional lab testing. However, these tests have suboptimal sensitivity and specificity. They are unable to indicate disease cause or guide physicians in decision-making for treatment. Therefore, there is an urgent need to develop a more accurate and robust tool for effective clinical management and drug development in lupus patients. It is fortunate that the emerging Omics have empowered scientists in the discovery and identification of potential novel biomarkers of SLE, especially the markers from blood, urine, cerebrospinal fluids (CSF), and other bodily fluids. However, many of these markers have not been carefully validated for clinical use. In addition, it is apparent that individual biomarkers lack sensitivity or specificity. This review summarizes the sensitivity, specificity and diagnostic value of emerging biomarkers from recent studies, and discusses the potential of these markers in the development of biomarker panel based diagnostics or disease monitoring system in SLE.

Radix Paeoniae Rubra Ameliorates Lupus Nephritis in Lupus-Like Symptoms of Mrl Mice by Reducing Intercellular Cell Adhesion Molecule-1, Vascular Cell Adhesion Molecule-1, and Platelet Endothelial Cell Adhesion Molecule-1 Expression

OBJECTIVE

Vasculitis is the basic pathological change of systemic lupus erythematosus (SLE). Radix Paeoniae Rubra (RPR), a traditional Chinese herb with the function of reducing blood stasis, has anti-inflammatory and immunoregulatory properties. This study explored the effects of RPR on the kidneys of lupus-like symptoms of mrl (MRL/lpr) mice from the perspective of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and platelet endothelial cell adhesion molecule-1 (PECAM-1).

METHODS

Eighteen MRL/lpr lupus model mice were randomly divided into three groups, the model control group, prednisone-treated group, and RPR-treated group, and 6 C57BL/ 6 mice were classified as a control group. After the mice had been treated for 12 weeks, the expression of ICAM-1, VCAM-1 and PECAM-1in the kidney was determined by immunohistochemistry and Reverse Transcription-Polymerase Chain Reaction (RT-PCR).

RESULTS

After 12 weeks, there were significant differences in body weight in the model, prednisone and RPR groups compared with the normal group (P <0.05). Pathological observation: Compared with the model group, the proliferation of inflammatory cells infiltrated glomeruli and interstitial cells in prednisone and RPR groups were reduced, and renal pathological damage was reduced. Compared with the model group, urine protein level of prednisone and RPR groups were reduced with no significance (P> 0.05). The mRNA expression levels of ICAM-1 and VCAM-1 were significantly reduced in the prednisone group and RPR group compared with the model group (P <0.05 or P <0.01). Meanwhile, the immunohistochemistry expressions of ICAM-1 and VCAM- 1 expressed in the kidney were significantly reduced in the prednisone group and RPR group (P <0.01 or P <0.05). However, The mRNA expression level and the immunohistochemistry expressions of PECAM-1 expressed in the kidney were reduced in each treatment group (prednisone group and RPR group), but these differences were not significant (P>0.05).

CONCLUSIONS

ICAM-1, VCAM-1 and PECAM-1 expression in the model group was found to be significantly increased. In addition, RPR could reduce the expression of ICAM-1, VCAM-1 and PECAM-1 in MRL/lpr lupus mice as effectively as prednisone, which may result in the dosage reduction of prednisone, thus decreasing the toxicity and improving the efficacy of prednisone - based treatment of SLE.

Clinical and Immunological Biomarkers for Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is characterized by immune system dysfunction and is clinically heterogeneous, exhibiting renal, dermatological, neuropsychiatric, and cardiovascular symptoms. Clinical and physiological assessment is usually inadequate for diagnosing and assessing pathophysiological processes in SLE. Clinical and immunological biomarkers could play a critical role in improving diagnosis, assessment, and ultimately, control of SLE. This article reviews clinical and immunological biomarkers that could diagnose and monitor disease activity in SLE, with and without organ-specific injury. In addition, novel SLE biomarkers that have been discovered through “omics” research are also reviewed.

Elevated Urinary and Blood Vascular Cell Adhesion Molecule-1 as Potential Biomarkers for Active Systemic Lupus Erythematosus: A Meta-analysis

OBJECTIVE

Due to the inconsistent results of current studies on the association between urinary and blood vascular cell adhesion molecule-1 (VCAM-1) and systemic lupus erythematosus (SLE) disease activity, we conducted this study and analyzed its influencing factors.

METHODS

A literature search was conducted in PubMed, EMBASE, Web of Science, and Cochrane Library. Data were extracted from eligible studies to calculate standardized mean differences (SMD) with 95% confidence intervals (CI). Cochrane Q test and I2 statistics were used to examine heterogeneity. The sources of heterogeneity were assessed through sensitivity analysis and subgroup analysis. Publication bias was evaluated by funnel plots and Egger's test.

RESULTS

A total of 15 studies met the inclusion criteria, including 473 active SLE patients and 674 inactive SLE patients. The random effects model was used for data analysis. In both urine and blood samples, VCAM- 1 level in active SLE patients was significantly higher than those in inactive SLE patients (urine: SMD: 0.769; 95% CI: 0.260-1.278; blood: SMD=0.655, 95% CI: 0.084-1.226). No publication bias was found in this study.

CONCLUSION

Compared with inactive SLE patients, patients with active SLE have higher levels of VCAM-1 in both urine and blood. VCAM-1 may be a potential indicator of SLE disease activity.

Clinico-pathological associations of serum VCAM-1 and ICAM-1 levels in patients with lupus nephritis

OBJECTIVE

We investigated the clinico-pathological associations of serum VCAM-1 and ICAM-1 levels in patients with biopsy-proven Class III/IV±V lupus nephritis (LN).

METHODS

Serum VCAM-1 and ICAM-1 levels were determined by ELISAs. Sera from patients with non-renal SLE or non-lupus chronic kidney disease (CKD), and healthy subjects served as controls.

RESULTS

Seropositivity rate for VCAM-1 and ICAM-1 was 93.10% and 37.93% respectively at the time of nephritic flare, and 44.83% and 13.79% respectively at remission, with both showing higher levels during flare (P < 0.05, for both). VCAM-1 level correlated with proteinuria, serum creatinine, and anti-dsDNA antibodies, and inversely correlated with C3. VCAM-1 level also correlated with leukocyte infiltration and fibrinoid necrosis/karyorrhexis scores in active LN kidney biopsies. ICAM-1 level correlated with proteinuria, but not anti-dsDNA or C3, nor histopathological features. VCAM-1 level increased 4.5 months before renal flare, while ICAM-1 increase coincided with flare, and both decreased after treatment. ROC analysis showed that VCAM-1 distinguished active LN from healthy subjects, LN in remission, active non-renal lupus, and CKD (ROC AUC of 0.98, 0.86, 0.93 and 0.90 respectively). VCAM-1 level in combination with either proteinuria or C3 was superior in distinguishing active LN from remission compared to the measurement of individual markers. Serum ICAM-1 level distinguished active LN from healthy subjects and LN patients in remission (ROC AUC of 0.75 and 0.66 respectively), but did not distinguish between renal versus non-renal lupus. ICAM-1 level in combination with markers of endothelial cell activation (syndecan-1, hyaluronan and thrombomodulin) was superior to proteinuria, anti-dsDNA, or C3 in distinguishing active LN from quiescent disease.

CONCLUSION

Our findings suggest potential utility of serum VCAM-1 and ICAM-1 in clinical management. Monitoring VCAM-1 may facilitate early diagnosis of flare. Combining selected biomarkers may be advantageous in diagnosing active LN. VCAM-1 may have a pathogenic role in renal parenchymal inflammation in active LN.

Urinary activated leukocyte cell adhesion molecule as a novel biomarker of lupus nephritis histology

Background

Lupus nephritis (LN) is one of the most severe complications of SLE patients. We aim to validate urinary ALCAM as a biomarker in predicting renal disease histpathology in a Chinese lupus cohort.

Methods

In this cross-sectional study, a total of 256 patients and controls were recruited. Urinary levels of ALCAM were determined by ELISA. Renal histopathology was reviewed by an experienced renal pathologist.

Results

Urinary ALCAM levels were significantly increased in active LN patients when compared to active SLE patients without renal involvement (p < 0.001), inactive LN patients (p = 0.023), inactive SLE patients without renal involvement (p < 0.001), and healthy controls (p < 0.001). Correlation analysis revealed a positive correlation between urinary ALCAM and general disease activity—SLEDAI score (r = 0.487, p < 0.001), as well as renal disease activity—rSLEDAI (r = 0.552, p < 0.001) and SLICC RAS (r = 0.584, p < 0.001). Urinary ALCAM also correlated with lab parameters including 24-h urine protein, hemoglobin, and complement 3. Moreover, urinary ALCAM levels were significantly increased in class III and IV (proliferative) LN as compared to those in class V (membranous) LN. It outperformed conventional biomarkers (anti-dsDNA antibody, C3, C4, proteinuria) in discriminating the two groups of LN. On renal histopathology, urinary ALCAM levels correlated positively with activity index (r = 0.405, p < 0.001) but not chronicity index (r = 0.079, p = 0.448).

Conclusion

Urinary ALCAM is a potential biomarker for predicting renal pathology activity in LN and may serve as a valuable surrogate marker of renal histopathology.

Effects of coal-fired PM2.5 on the expression levels of atherosclerosis-related proteins and the phosphorylation level of MAPK in ApoE-/- mice

Background

Air pollution increases the morbidity and mortality of cardiovascular disease (CVD). Atherosclerosis (AS) is the pathological basis of most CVD, and the progression of atherosclerosis and the increase of fragile plaque rupture are the mechanism basis of the relationship between atmospheric particulate pollution and CVD. The aim of the present study was to investigate the effects of coal-fired fine particulate matter (PM_2.5) on the expression levels of atherosclerosis-related proteins (von Willebrand factor (vWF), Endothelin-1 (ET-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin, and to explore the role and mechanism of the progression of atherosclerosis induced by coal-fired PM_2.5 via the mitogen-activated protein kinase (MAPK) signaling pathways.

Methods

Different concentrations of PM_2.5 were given to apolipoprotein-E knockout (ApoE^−/−) mice via intratracheal instillation for 8 weeks. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of vWF, ET-1 in serum of mice. Immunohistochemistry was used to observe the expression and distribution of ICAM-1 and E-selectin in the aorta of mice. Western blot was used to investigate the phosphoylation of proteins relevant to MAPK signaling pathways.

Results

Coal-fired PM_2.5 exacerbated atherosclerosis induced by a high-fat diet. Fibrous cap formation, foam cells accumulation, and atherosclerotic lesions were observed in the aortas of PM_2.5-treated mice. Coal-fired PM_2.5 increased the protein levels of ET-1, ICAM-1, and E-selectin, but there was no significant difference in the vWF levels between the PM_2.5-treatment mice and the HFD control mice. Coal-fired PM_2.5 promoted the phosphorylation of p38, c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) in aortic tissues of mice.

Conclusion

Coal-derived PM_2.5 exacerbated the formation of atherosclerosis in mice, increased the expression levels of atherosclerosis-related proteins in mice serum, and promoted the phosphorylation of proteins relevant to MAPK signaling pathway. Thus, MAPK signaling pathway may play a role in the atherosclerosis pathogenesis induced by Coal-derived PM_2.5.

Immune gene expression in kidney biopsies of lupus nephritis patients at diagnosis and at renal flare

BACKGROUND

Up to 50% of lupus nephritis (LN) patients experience renal flares after their initial episode of LN. These flares contribute to poor renal outcomes. We postulated that intrarenal immune gene expression is different in flares compared with de novo LN, and conducted these studies to test this hypothesis.

METHODS

Glomerular and tubulointerstitial immune gene expression was evaluated in 14 patients who had a kidney biopsy to diagnose LN and another biopsy at their first LN flare. Ten healthy living kidney donors were included as controls. RNA was extracted from laser microdissected formalin-fixed paraffin-embedded kidney biopsies. Gene expression was analyzed using the Nanostring nCounter® platform and validated by quantitative real-time polymerase chain reaction. Differentially expressed genes were analyzed by the Ingenuity Pathway Analysis and Panther Gene Ontology tools.

RESULTS

Over 110 genes were differentially expressed between LN and healthy control kidney biopsies. Although there was considerable molecular heterogeneity between LN biopsies at diagnosis and flare, for about half the LN patients gene expression from the first LN biopsy clustered with the repeated LN biopsy. However, in all patients, a set of eight interferon alpha-controlled genes had a significantly higher expression in the diagnostic biopsy compared with the flare biopsy. In contrast, nine tumor necrosis factor alpha-controlled genes had higher expression in flare biopsies.

CONCLUSIONS

There is significant heterogeneity in immune-gene expression of kidney tissue from LN patients. There are limited but important differences in gene expression between LN flares, which may influence treatment decisions.

Soluble Vascular Cell Adhesion Molecule-1 Is Associated With Disease Activity in Adult-Onset Minimal Change Disease

BACKGROUND

Cell adhesion molecules have been documented to be elevated in numerous immune inflammatory diseases. Minimal change disease (MCD) is an immune disorder. This study aimed to evaluate whether levels of soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble E-selectin (sE-selectin) reflect disease activity in adult-onset MCD.

METHODS

A sandwich enzyme-linked immunosorbent assay was used to measure the soluble adhesion molecules in 40 patients with nephrotic-range proteinuria and biopsy-proven MCD, obtained at the time of diagnosis and during remission. Thirty-five age- and sex-matched healthy volunteers served as controls.

RESULTS

Patients with MCD during the active stage showed significantly higher levels of sVCAM-1 and sE-selectin when compared to controls. Moreover, sVCAM-1 had significantly positive correlations with both urine protein and serum cholesterol, and was negatively associated with serum albumin. Multiple analyses showed that serum albumin was an independent predictor of sVCAM-1. The correlations between sE-selectin and other clinical parameters were not statistically significant. At follow-up, these markers systematically decreased as the disease went into remission, but the increase in sVCAM-1 persisted even in patients obtaining complete remission for 6 months.

CONCLUSIONS

Patients with active MCD had increased levels of sVCAM-1 and sE-selectin. The correlation between sVCAM-1 and proteinuria, serum albumin and cholesterol and its decline during remission indicate that sVCAM-1 is associated with disease activity.

Cytochrome P450: Polymorphisms and Roles in Cancer, Diabetes and Atherosclerosis

Cytochromes P450s (CYPs) constitute a superfamily of enzymes that catalyze the metabolism of drugs and other substances. Endogenous substrates of CYPs include eicosanoids, estradiol, arachidonic acids, cholesterol, vitamin D and neurotransmitters. Exogenous substrates of CYPs include the polycyclic aromatic hydrocarbons and about 80% of currently used drugs. Some isoforms can activate procarcinogens to ultimate carcinogens. Genetic polymorphisms of CYPs may affect the enzyme catalytic activity and have been reported among different populations to be associated with various diseases and adverse drug reactions. With regard of drug metabolism, phenotypes for CYP polymorphism range from ultrarapid to poor metabolizers. In this review, we discuss some of the most clinically important CYPs isoforms (CYP2D6, CYP2A6, CYP2C19, CYP2C9, CYP1B1 and CYP1A2) with respect to gene polymorphisms and drug metabolism. Moreover, we review the role of CYPs in renal, lung, breast and prostate cancers and also discuss their significance for atherosclerosis and type 2 diabetes mellitus.

Increased adhesion molecule levels in systemic lupus erythematosus: relationships with severity of illness, autoimmunity, metabolic syndrome and cortisol levels

Background

This study was performed to assess adhesion molecules in systemic lupus erythematosus (SLE).

Methods

This case-control study examined 126 SLE patients and 48 healthy individuals. Blood levels of six adhesion molecules, cortisol, nuclear autoantibody (ANA) and anti-double stranded DNA (anti-dsDNA) titers were measured, while disease activity was assessed using the SLE Disease Activity Index (SLEDAI) score.

Results

Platelet endothelial cell adhesion molecule 1 (PECAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin, P-selectin, and plasminogen activator inhibitor type-1 (PAI-1) were significantly higher in SLE patients than in controls. Binary logistic regression analysis showed that PECAM-1 and PAI-1 predicted SLE with a sensitivity of 86.5% and a specificity of 81.3%. ANA titers were significantly and positively associated with PECAM-1, VCAM-1, E-selectin, and PAI-1, whereas there were no associations between anti-dsDNA titers and adhesion molecules. Cortisol was negatively associated with PCAM-1 and ICAM-1. There were significant associations between metabolic syndrome (MetS) and E-selectin and PAI-1. 14.8% of the variance in the SLEDAI score was explained by the regression on PECAM-1 and MetS.

Conclusions

Our data show that adhesion molecules, especially PECAM-1, are significantly associated with SLE and disease activity, suggesting that they play a role in SLE pathophysiology. While MetS, ANA titers and cortisol levels modulate adhesion molecule levels, these associations do not explain the increased levels of adhesion molecules in SLE. Increased levels of adhesion molecules are new drug targets in SLE.

Urine angiostatin and VCAM-1 surpass conventional metrics in predicting elevated renal pathology activity indices in lupus nephritis

AIM

The goal of this study is to investigate how urinary angiostatin, vascular cell adhesion molecule 1 (VCAM-1) and established measures of renal function relate to specific histologic findings in paired kidney biopsy samples from patients with lupus nephritis (LN).

METHOD

Urine samples were collected from 54 LN patients together with paired kidney biopsy samples and examined for urinary angiostatin and VCAM-1 protein levels. Nonparametric tests were used to examine the association of both urinary biomarkers and established traditional laboratory markers of renal function with nine specific renal histologic features seen in LN, including glomerular leukocyte infiltration, endocapillary proliferation, cellular crescents, fibrinoid necrosis, wire loops, interstitial inflammation, glomerulosclerosis, fibrous crescents, tubular atrophy and interstitial fibrosis.

RESULTS

Compared to traditional renal disease metrics, both urinary angiostatin and VCAM-1 exhibited outstanding potential (area under the curve 0.97, 0.98, respectively) to predict renal biopsy activity index score ≥ 7, which is associated with poor long-term prognosis. Whereas urine VCAM-1 was most significantly associated with fibrous crescents, urine angiostatin was most significantly associated with endocapillary proliferation, cellular crescents, fibrinoid necrosis and fibrous crescents in concurrent renal biopsies.

CONCLUSION

Urinary angiostatin and VCAM-1 are predictive of specific histological changes in concurrent LN renal biopsies. Both urinary biomarkers are good candidates for use as noninvasive measures of renal pathology activity changes in LN.

Organ-specific biomarkers in lupus

Systemic lupus erythematosus (SLE) is a complex and highly heterogeneous disease, which affects multiple organs, including joints, skin, kidneys, heart, hematopoietic system, and nerve system. While the etiopathogenesis of SLE still remains unclear, genetic susceptibilities and aberrant epigenetic modifications are believed to be involved. For precision therapy, it is necessary to assess accurately and objectively organ involvements and disease activity, which is difficult by current clinical laboratory tests. Biomarkers, which are a biologic, genetic, epigenetic or a chemical characteristic and conveniently detectable, serve as measures of disease diagnosis, activity, prognosis, and manifestation prediction, thereby providing instruction for individualized therapy. In addition, biomarkers differ according to different manifestations, since the disease activity index and treatments vary significantly. For example, unlike other non-renal SLE, lupus nephritis requires significant immunosuppressive drugs. Over the past decades, the research on biomarkers in lupus has been strengthened and numerous promising biomarkers have been identified at levels of genomics, transcriptomics and proteomics. In this review, we summarize the conventional and novel biomarkers in the tissue-specific manner, and discuss their roles in specific organ diagnosis, future manifestation prediction, disease activity assessment and their correlation with histology results. By doing so, it aims to shed a light on individualized treatment.

Lupus nephritis biomarkers

Lupus nephritis (LN), a potentially destructive outcome of SLE, is a real challenge in the management of SLE because of the difficulty in diagnosing its subclinical onset and identifying relapses before serious complications set in. Conventional clinical parameters such as proteinuria, GFR, urine sediments, anti-dsDNA and complement levels are not sensitive or specific enough for detecting ongoing disease activity in lupus kidneys and early relapse of nephritis. There has long been a need for biomarkers of disease activity in LN. Such markers ideally should be capable of predicting early sub-clinical flares and could be used to gauge response to therapy, thus obviating the need for serial renal biopsies with their possible hazardous complications. Since urine can be readily obtained, it lends itself as an obvious biological substrate. In this review, the use of urine and serum as sources of lupus nephritis biomarkers is described, and the results of biomarker discovery studies using candidate and proteomic approaches are summarized.

Antibody-Array-Based Proteomic Screening of Serum Markers in Systemic Lupus Erythematosus: A Discovery Study

A discovery study was carried out where serum samples from 22 systemic lupus erythematosus (SLE) patients and matched healthy controls were hybridized to antibody-coated glass slide arrays that interrogated the level of 274 human proteins. On the basis of these screens, 48 proteins were selected for ELISA-based validation in an independent cohort of 28 SLE patients. Whereas AXL, ferritin, and sTNFRII were significantly elevated in patients with active lupus nephritis (LN) relative to SLE patients who were quiescent, other molecules such as OPN, sTNFRI, sTNFRII, IGFBP2, SIGLEC5, FAS, and MMP10 exhibited the capacity to distinguish SLE from healthy controls with ROC AUC exceeding 90%, all with p < 0.001 significance. These serum markers were next tested in a cohort of 45 LN patients, where serum was obtained at the time of renal biopsy. In these patients, sTNFRII exhibited the strongest correlation with eGFR (r = -0.50, p = 0.0014) and serum creatinine (r = 0.57, p = 0.0001), although AXL, FAS, and IGFBP2 also correlated with these clinical measures of renal function. When concurrent renal biopsies from these patients were examined, serum FAS, IGFBP2, and TNFRII showed significant positive correlations with renal pathology activity index, while sTNFRII displayed the highest correlation with concurrently scored renal pathology chronicity index (r = 0.57, p = 0.001). Finally, in a longitudinal cohort of seven SLE patients examined at ∼3 month intervals, AXL, ICAM-1, IGFBP2, SIGLEC5, sTNFRII, and VCAM-1 demonstrated the ability to track with concurrent disease flare, with significant subject to subject variation. In summary, serum proteins have the capacity to identify patients with active nephritis, flares, and renal pathology activity or chronicity changes, although larger longitudinal cohort studies are warranted.

Biomarkers in lupus nephritis

Lupus nephritis (LN) has significant impact on the outcome of patients with systemic lupus erythematosus (SLE). In the absence of any new breakthrough for management of LN over the last few years, using existing treatment modalities in a more effective manner is the mainstay of improving outcomes. For effectively using the drugs, disease activity needs to be assessed accurately and more objectively, which is not possible with present clinical assessment tools. Biomarkers help in accurate assessment of disease activity and enable the physician to individualize the therapy. Conventional disease activity markers have limitations which need to be addressed and research in the area of biomarker discovery in LN has immensely expanded over the last two decades as evident by the literature. Moreover, biomarkers for LN should be different from the markers of overall disease activity as LN requires significant immunosuppression, unlike other non-renal manifestations of SLE. Newly discovered biomarkers exhibit qualities pertaining to different aspects of disease activity and damage. In this review, we discuss the established as well as new biomarkers of SLE in the light of their role in LN diagnosis, follow-up, prediction of renal flare and correlation with renal histology findings.

Niacin Suppresses Progression of Atherosclerosis by Inhibiting Vascular Inflammation and Apoptosis of Vascular Smooth Muscle Cells

Background

Niacin is a broad-spectrum lipid-regulating drug used for the clinical therapy of atherosclerosis; however, the mechanisms by which niacin ameliorates atherosclerosis are not clear.

Material/Methods

The effect of niacin on atherosclerosis was assessed by detection of atherosclerotic lesion area. Adhesion molecules in arterial endothelial cells were determined by using qRT-PCR and Western blot analysis. The levels of serum inflammatory cytokines in ApoE^−/− mice were detected by using ELISA. We detected the expression levels of phosphorylated nuclear factors-κB (NF-κB) p65 in aortic endothelial cells of mice using Western blot analysis. Furthermore, we investigated the anti-inflammation effect and endothelium-protecting function of niacin and their regulatory mechanisms in vitro.

Results

Niacin inhibited the progress of atherosclerosis and decreased the levels of serum inflammatory cytokines and adhesion molecules in ApoE^−/− mice. Niacin suppressed the activity of NF-κB and apoptosis of vascular smooth muscle cells (VSMCs). Furthermore, niacin induced phosphorylated focal adhesion kinase (FAK) and FAK inhibitor PF-573228 reduced the level of Bcl-2 and elevated the level of cleaved caspase-3 in VSMCs.

Conclusions

Niacin inhibits vascular inflammation and apoptosis of VSMCs via inhibiting the NF-κB signaling and the FAK signaling pathway, respectively, thus protecting ApoE^−/− mice against atherosclerosis.

Systemic lupus erythematosus: An update for ophthalmologists

Systemic lupus erythematosus (SLE) is a life-threatening multisystem inflammatory condition that may affect almost any part of the eye. We provide an update for the practicing ophthalmologist comprising a systematic review of the recent literature presented in the context of current knowledge of the pathogenesis, diagnosis, and treatment of this condition. We review recent advances in the understanding of the influence of genetic and environmental factors on the development of SLE. Recent changes in the diagnostic criteria for SLE are considered. We assess the potential for novel molecular biomarkers to find a clinical application in disease diagnosis and stratification and in the development of therapeutic agents. We discuss limited forms of SLE and their differentiation from other collagen vascular disorders and review recent evidence underlying the use of established and novel therapeutics in this condition, including specific implications regarding monitoring for ocular toxicity associated with antimalarials.

Biomarkers for childhood-onset systemic lupus erythematosus

Childhood-onset systemic lupus erythematosus (cSLE) is a systemic autoimmune disease characterized by the presence of autoantibodies. cSLE often affects multiple organs in the body and is known to have a poorer prognosis than adult-onset disease (Azevedo et al. 2014). Current laboratory tests are clearly insufficient for identifying and monitoring the disease. Recent studies have yielded novel biomarkers for cSLE which can be used for monitoring disease activity and response to treatment. The most encouraging biomarkers will be discussed herein and include cell-bound complement activation products, some genomic profiles, and urinary proteins such as neutrophil gelatinase-associated lipocalin, monocyte chemoattractant protein-1, and others. Previous studies suggested that a combination of the novel biomarkers might help to enhance sensitivity and specificity for early diagnosis, disease monitoring, and prediction of cSLE flares.