Decreases in anti-double-stranded DNA levels are associated with concurrent flares in patients with systemic lupus erythematosus

Differential efficacy of human mesenchymal stem cells based on source of origin

Mesenchymal stem cells (MSCs) are useful in tissue repair but also possess immunomodulatory properties. Murine and uncontrolled human trials suggest efficacy of MSCs in treating lupus. Autologous cells are preferable; however, recent studies suggest that lupus-derived MSCs lack efficacy in treating disease. Thus, the optimum derivation of MSCs for use in lupus is unknown. It is also unknown which in vitro assays of MSC function predict in vivo efficacy. The objectives for this study were to provide insight into the optimum source of MSCs and to identify in vitro assays that predict in vivo efficacy. We derived MSCs from four umbilical cords, four healthy bone marrows (BMs), and four lupus BMs. In diseased MRL/lpr mice, MSCs from healthy BM and umbilical cords significantly decreased renal disease, whereas lupus BM MSCs only delayed disease. Current in vitro assays did not differentiate efficacy of the different MSCs. However, differences in MSC efficacy were observed in B cell proliferation assays. Our results suggest that autologous MSCs from lupus patients are not effective in treating disease. Furthermore, standard in vitro assays for MSC licensing are not predictive of in vivo efficacy, whereas inhibiting B cell proliferation appears to differentiate effective MSCs from ineffective MSCs.

An integrated extrapolation of long-term outcomes in systemic lupus erythematosus: analysis and simulation of the Hopkins lupus cohort

OBJECTIVE

The aim of this study was to develop an SLE disease model that simulates long-term outcomes of SLE to estimate the long-term effectiveness and cost-effectiveness of SLE treatments.

METHODS

Longitudinal data from 1354 patients from the Hopkins Lupus Cohort were included in the analysis. Statistical models were created to estimate disease activity [Safety of Estrogen in Lupus Erythematosus National Assessment (SELENA) SLEDAI scale] and prednisone dose over time using linear regression. Survival models for organ damage and mortality were created. The models were combined in a predictive simulation of SLE organ damage and mortality. Predictions were assessed against the Hopkins Lupus Cohort data.

RESULTS

The analyses found that change in the annual average SLEDAI score was associated with the previous annual average SLEDAI score, renal involvement, age, male gender, African American ethnicity, anaemia, haematological involvement, increased DNA binding and low complement. The annual average prednisone dose increased for every unit increase in annual average SLEDAI. Organ damage and mortality modelling demonstrated that adjusted mean SLEDAI and binary SLEDAI organ involvement indicators predicted mortality, cardiovascular, renal, neuropsychiatric, pulmonary, gastrointestinal, ocular and skin damage. The cumulative average prednisone dose was associated with risk of cardiovascular, ocular, musculoskeletal, neuropsychiatric and gastrointestinal damage, gonadal failure and diabetes mellitus. The simulation reproduced mean SLEDAI and organ damage scores from the Hopkins Lupus Cohort.

CONCLUSION

Longitudinal modelling of an SLE cohort confirmed relationships between risk factors and long-term outcomes in SLE. The models serve to estimate the probability of SLE outcomes over time and can be used to estimate the effectiveness and cost-effectiveness of new treatments.

Increased urinary interleukin 22 binding protein levels correlate with lupus nephritis activity

OBJECTIVE

Interleukin 22 (IL-22) plays an important role in the promotion of antimicrobial immunity. However, dysregulated IL-22 action leads to inflammation and is involved in autoimmune diseases, including systemic lupus erythematosus (SLE). IL-22 binding protein (IL-22BP) is a soluble inhibitory IL-22 receptor and may represent a crucial regulator of IL-22. We investigated the expression and potential significance of serum and urinary IL-22BP levels in patients with SLE.

METHODS

A total of 112 patients with SLE and healthy control subjects participated in our study. Patients were classified according to kidney involvement and disease activity based on clinical and laboratory measures such as urinary sediment, proteinuria, kidney function, complement factor 3 (C3), C4, anti-dsDNA, disease activity index, and renal SLE disease activity index. The concentrations of IL-22BP and IL-22 were measured by ELISA. The expression of IL-22BP in the renal tissue was detected by immunohistochemistry.

RESULTS

Patients with active renal disease had urinary levels of IL-22BP higher than (1) patients with active SLE but no renal involvement, (2) patients with a history of lupus nephritis in remission with no systemic disease activity and no history of renal involvement, and (3) control subjects. There was no difference in serum levels of IL-22BP among the groups. Urinary levels of IL-22BP in patients with active renal disease were positively correlated with SLE Disease Activity Index, Systemic Lupus International Collaborating Clinics renal activity score, and histological activity index. IL-22BP was highly expressed in renal tissue of patients with active renal disease. After 6 months of treatment, urinary IL-22BP levels decreased significantly in patients with complete response, but remained unchanged in those with partial or no response.

CONCLUSION

Urinary but not serum IL-22BP levels were associated with active renal disease. Urinary levels of IL-22BP might be a potential marker for the presence of renal involvement in patients with SLE.

Correlation between cell free DNA levels and medical evaluation of disease progression in systemic lupus erythematosus patients

High levels of cell free DNA (cfDNA) in human blood plasma have been described in patients with autoimmune diseases. The aim of this study was to determine the levels of cfDNA in systemic lupus erythematosus (SLE) patients and to assess fluctuations of cfDNA concentrations compared to the course of disease progression under standard treatment. Therefore, nuclear cfDNA concentrations in plasma were measured in 59 SLE patients and 59 healthy controls. Follow-up blood plasma was collected from 27 of the 59 SLE patients. Patients were characterised by clinical parameters (antinuclear antibodies (ANA), anti-dsDNA-antibodies, C3, C4, and CRP), SLE disease activity index (SLEDAI) and medical therapy. Our results showed that cfDNA concentrations were significantly higher in SLE patients compared to healthy individuals. Levels of cfDNA assessed in serial samples correlated significantly with the medical evaluation of disease activity in SLE patients. Our results could implicate cfDNA as a global marker for disease activity.

Peptidylarginine deiminase inhibition disrupts NET formation and protects against kidney, skin and vascular disease in lupus-prone MRL/lpr mice

OBJECTIVES

An imbalance between neutrophil extracellular trap (NET) formation and degradation has been described in systemic lupus erythematosus (SLE), potentially contributing to autoantigen externalisation, type I interferon synthesis and endothelial damage. We have demonstrated that peptidylarginine deiminase (PAD) inhibition reduces NET formation and protects against lupus-related vascular damage in the New Zealand Mixed model of lupus. However, another strategy for inhibiting NETs--knockout of NOX2--accelerates lupus in a different murine model, MRL/lpr. Here, we test the effects of PAD inhibition on MRL/lpr mice in order to clarify whether some NET inhibitory pathways may be consistently therapeutic across models of SLE.

METHODS

NET formation and autoantibodies to NETs were characterised in lupus-prone MRL/lpr mice. MRL/lpr mice were also treated with two different PAD inhibitors, Cl-amidine and the newly described BB-Cl-amidine. NET formation, endothelial function, interferon signature, nephritis and skin disease were examined in treated mice.

RESULTS

Neutrophils from MRL/lpr mice demonstrate accelerated NET formation compared with controls. MRL/lpr mice also form autoantibodies to NETs and have evidence of endothelial dysfunction. PAD inhibition markedly improves endothelial function, while downregulating the expression of type I interferon-regulated genes. PAD inhibition also reduces proteinuria and immune complex deposition in the kidneys, while protecting against skin disease.

CONCLUSIONS

PAD inhibition reduces NET formation, while protecting against lupus-related damage to the vasculature, kidneys and skin in various lupus models. The strategy by which NETs are inhibited will have to be carefully considered if human studies are to be undertaken.

Mesangial cell-binding activity of serum immunoglobulin g in patients with lupus nephritis

In vitro data showed that immunoglobulin G (IgG) from patients with lupus nephritis (LN) could bind to cultured human mesangial cells (HMC). The clinical relevance of such binding was unknown. Binding of IgG and subclasses was measured in 189 serial serum samples from 23 patients with Class III/IV±V LN (48 during renal flares, 141 during low level disease activity (LLDA)). 64 patients with non-lupus glomerular diseases (NLGD) and 23 healthy individuals were used as controls. HMC-binding was measured with cellular ELISA and expressed as OD index. HMC-binding index of total IgG was 0.12±0.09, 0.36±0.25, 0.59±0.37 and 0.74±0.42 in healthy subjects, NLGD, LN patients during LLDA, and LN flares respectively (P = 0.046, LN flare vs. LLDA; P<0.001, for healthy controls or NLGD vs. LN during flare or LLDA). Binding of serum IgG₁ to HMC was 0.05±0.05, 0.15±0.11, 0.41±0.38 and 0.55±0.40 for the corresponding groups respectively (P = 0.007, LN flare vs. remission; P<0.001, for healthy controls or NLGD vs. LN during flare or remission). IgG₂, IgG₃ and IgG₄ from patients and controls did not show significant binding to HMC. Total IgG and IgG₁ HMC-binding index correlated with anti-dsDNA level (r = 0.26 and 0.39 respectively, P<0.001 for both), and inversely with C3 (r = −0.17 and −0.45, P<0.05 for both). Sensitivity/specificity of total IgG or IgG₁ binding to HMC in predicting renal flares were 81.3%/39.7% (ROC AUC 0.61, P = 0.03) and 83.8%/41.8% (AUC 0.63, P = 0.009) respectively. HMC-binding by IgG_1, but not total IgG, correlated with mesangial immune deposition in LN renal biopsies under electron microscopy. Our results showed that binding of serum total IgG and IgG₁ in LN patients correlates with disease activity. The correlation between IgG₁ HMC-binding and mesangial immune deposition suggests a potential pathogenic significance.

Elevated signal transducers and activators of transcription 1 correlates with increased C-C motif chemokine ligand 2 and C-X-C motif chemokine 10 levels in peripheral blood of patients with systemic lupus erythematosus

INTRODUCTION

The present study examines the levels of recently reported biomarkers, adenosine deaminase acting on RNA (ADAR), C-C motif chemokine ligand 2 (CCL2), C-X-C motif chemokine 10 (CXCL10), signal transducers and activators of transcription 1 (STAT1), and miR-146a in systemic lupus erythematosus (SLE) patients over multiple visits.

METHODS

Peripheral blood leukocytes were collected from 65 healthy donors and 103 SLE patients, 60 of whom had samples from 2 or more visits. Total RNA was isolated and analyzed for the expression of mRNA and microRNA using Taqman real time PCR assays. Relative expression of I-IFN signature genes, chemokines, and miR-146a were determined by the ΔΔCT method. Results were correlated with clinical data and analyzed by Wilcoxon/Kruskal-Wallis test and Fisher's exact test.

RESULTS

Levels of ADAR, CCL2, CXCL10, and STAT1 in SLE were significantly elevated compared with the healthy controls (P <0.0001). ADAR, CCL2, and CXCL10 showed significant correlation with IFN score in both healthy donors (P <0.0033) and SLE patients (P <0.0001). In SLE patients, miR-146a level was not significantly different from healthy controls nor correlated to the IFN score. Two STAT1 populations were identified: a low STAT1 and a high STAT1 group. High STAT1 patient visits displayed higher (P ≤0.0020) levels of CCL2 and CXCL10 than the low STAT1 patient visits. STAT1 levels correlated with IFN score in low STAT1 group but not in high STAT1 group. More importantly, high STAT1 levels appeared as an enhancer of CCL2 and CXCL10 as indicated by the significantly stronger correlation of CCL2 and CXCL10 with IFN score in high STAT1 patient visits relative to low STAT1 patient visits.

CONCLUSION

Our data indicate a novel role for STAT1 in the pathogenesis of SLE as an expression enhancer of CCL2 and CXCL10 in SLE patients with high levels of STAT1. Future study is needed to examine the exact role of STAT1 in the etiology of SLE.

A surge in anti-dsDNA titer predicts a severe lupus flare within six months

OBJECTIVE

Rising anti-double-stranded (ds) DNA titers have been shown by some, but not all, studies to be predictive of disease flares in systemic lupus erythematosus (SLE). We hypothesized that a rapid and substantial rise in anti-dsDNA titer (anti-dsDNA surge) would be a good predictor of a clinically important SLE flare.

METHODS

A matched case-control study was conducted in an academic rheumatology practice setting. Our primary endpoint was the occurrence of a severe SELENA-SLEDAI (SS) flare within six months of an anti-dsDNA surge, and secondary endpoints were mild/moderate SS flares, as well as BILAG A and B renal flares. Cases were identified as those patients whose disease course included a surge of anti-dsDNA, defined as an increase of anti-dsDNA titer by the Crithidia luciliae immunofluorescence (CLIF) assay from 0 to 3+/4+, or from 1+ to 4+, within a period of less than 12 months. The date of the anti-dsDNA surge was defined as Day 0. Two control SLE patients were identified for each case and were matched for age, sex, race, and visit date closest to case Day 0, but without an anti-dsDNA surge. Logistic regression models were used to detect associations between anti-dsDNA surges and severe SS flares.

RESULT

A higher proportion of cases, compared to controls, experienced a severe SS flare within six months of Day 0 (OR 6.3 (95% confidence intervals 2.0-19.9), p = 0.02). Associations with all flares and hospitalizations for flares were also observed. However, an anti-dsDNA surge was not predictive of a renal flare.

CONCLUSION

An anti-dsDNA surge predicts the subsequent development of a severe SS flare within six months. Physicians should closely monitor such patients and treat promptly at the first sign of clinical activity.

Assessment of disease activity, damage and quality of life in systemic lupus erythematosus: new aspects

Systemic lupus erythematosus (SLE) is a multisystem auto-immune disorder that results from a combination of genetic, environmental and hormonal factors. The heterogeneity of disease presentation and course in different individuals and the variability in the disease progression/fluctuations within the same patient have made finding a unifying assessment tool difficult. It is currently accepted that assessment of patients with SLE cannot be accomplished with a single index. Formal evaluation of three aspects of the disease, disease activity, disease damage and patient-related quality of life (QoL), is required. In the recent decade, the pathogenesis of SLE at the cellular and molecular levels has been the subject of much research. Robust assessment tools are needed to correlate the presence of various serological markers with disease activity. In addition, multiple clinical trials of new therapies have necessitated validated measures that can give a sensitive response index. This review focusses on the SLE assessment tools currently in use and their translational application in clinical research and trials.

Changes in Farr radioimmunoassay and EliA fluorescence immunoassay anti-dsDNA in relation to exacerbation of SLE

Measuring anti-dsDNA levels could support treatment adjustment during follow-up of patients with systemic lupus erythematosus (SLE). We investigated whether patients with exacerbations of SLE showed changes in anti-double-stranded DNA (anti-dsDNA) levels prior to the exacerbation using the Farr and EliA assay and examined which assay showed highest specificity and predictive value for exacerbations. Changes in anti-dsDNA of ≥ 25% prior to exacerbation were considered of clinical significance. Exacerbations were retrospectively abstracted from medical records. Eighteen of 48 patients showed one or more exacerbations. We found 22 exacerbations with complete lab work-up, all accompanied by ≥ 25% change in anti-dsDNA in one or both assays. Only 10 exacerbations showed concordant changes in anti-dsDNA in both assays. Changes in anti-dsDNA had a low predictive value for exacerbations of SLE, but the specificity of anti-dsDNA changes for patients with exacerbations was higher for EliA than Farr. We conclude that despite the limited relation between anti-dsDNA changes and exacerbations of SLE, anti-dsDNA testing could still support clinical decision making when used in the correct setting. We conclude that EliA is preferable over Farr for assaying anti-dsDNA during follow-up of patients with SLE because of higher specificity, less "hands-on" time and absence of radioactivity.

Detection of autoantibodies in a point-of-care rheumatology setting

Autoimmune rheumatic diseases are common and confront society with serious medical, social, and financial burdens imposed by their debilitating nature. Many autoimmune diseases are associated with a particular set of autoantibodies, which have emerged as highly useful to define and classify disease, predict flares, or monitor efficacy of therapy. However, current practice for monitoring autoantibodies is protracted, labor-intensive, and expensive. This review provides an overview on the value of point-of-care (POC) biosensor technology in the diagnosis and management of patients with autoimmune rheumatic diseases. Real-time measurement of autoantibodies will clearly benefit the rheumatology practice in emergency and urgent care settings, where definitive diagnosis is essential for initiation of correct critical care therapy. Immediate serological information in clinic will provide considerable value for long-term patient care and an opportunity for an instant, result-deduced therapeutic action, avoiding delays and improving compliance, especially in field-based and remote areas. We describe the particular autoantibodies that are useful disease and activity markers and would, therefore, be attractive to POC applications. Already existing biosensors and platforms that show promise for autoantibody testing are summarized and comparatively evaluated. As POC assessment is gaining momentum in several areas of patient care, we propose that rheumatology is poised to benefit from this innovative and affordable technology.

Peptidylarginine deiminase inhibition is immunomodulatory and vasculoprotective in murine lupus

Recent evidence suggests that enhanced neutrophil extracellular trap (NET) formation activates plasmacytoid dendritic cells and serves as a source of autoantigens in SLE. We propose that aberrant NET formation is also linked to organ damage and to the premature vascular disease characteristic of human SLE. Here, we demonstrate enhanced NET formation in the New Zealand mixed 2328 (NZM) model of murine lupus. NZM mice also developed autoantibodies to NETs as well as the ortholog of human cathelicidin/LL37 (CRAMP), a molecule externalized in the NETs. NZM mice were treated with Cl-amidine, an inhibitor of peptidylarginine deiminases (PAD), to block NET formation and were evaluated for lupus-like disease activity, endothelial function, and prothrombotic phenotype. Cl-amidine treatment inhibited NZM NET formation in vivo and significantly altered circulating autoantibody profiles and complement levels while reducing glomerular IgG deposition. Further, Cl-amidine increased the differentiation capacity of bone marrow endothelial progenitor cells, improved endothelium-dependent vasorelaxation, and markedly delayed time to arterial thrombosis induced by photochemical injury. Overall, these findings suggest that PAD inhibition can modulate phenotypes crucial for lupus pathogenesis and disease activity and may represent an important strategy for mitigating cardiovascular risk in lupus patients.

Unmet medical needs in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease of diverse manifestations, with onset usually in young women in the third to fourth decade of life. The chronic nature of this relapsing remitting disease leads to organ damage accrual over time. Mortality and morbidity are increased in patients with SLE compared with the general population. Therapeutic advances over the last few decades have led to significant improvements in patient outcomes. Five-year survival has improved to over 90% from a low of 50% in the 1950s. However, multiple aspects of the management of SLE patients are still far from optimal. Early diagnosis remains a challenge; diagnostic delays leading to delay in definitive treatment are common. Monitoring treatment remains problematic due to the paucity of sensitive biomarkers. Current treatment regimens rely heavily on corticosteroids, even though corticosteroids are well known to cause organ damage. Treatment of refractory disease manifestations such as nephritis, recalcitrant cutaneous lesions and neurological involvement require new approaches with greater efficacy. Cognitive dysfunction is common in SLE patients, but early recognition and adequate treatment are yet to be established. Premature accelerated atherosclerosis remains a leading cause of morbidity and mortality. Fatigue is one of the most disabling symptoms, and contributes to the poor quality of life in patients with SLE. Ongoing research in SLE faces many challenges, including enrollment of homogeneous patient populations, use of reliable outcome measures and a standard control arm. The current review will highlight some of the outstanding unmet challenges in the management of this complex disease.

Laser in situ keratomileusis in patients with collagen vascular disease: a review of the literature

PURPOSE

To evaluate the current United States Food and Drug Administration (FDA) recommendations regarding laser in situ keratomileusis (LASIK) surgery in patients with collagen vascular diseases (CVD) and assess whether these patients make appropriate candidates for laser vision correction, and offer treatment recommendations based on identified clinical data.

METHODS

A literature search was conducted using PubMed, Medline, and Ovid to identify all existing studies of LASIK in patients with collagen vascular diseases. The search was conducted without date limitations. Keywords used for the search included MeSH terms: laser in situ keratomileusis, LASIK, refractive surgery, ocular surgery, and cataract surgery connected by "and" with the following MeSH and natural-language terms: collagen vascular disease, rheumatic disease, systemic disease, rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome, seronegative spondyloarthropathy, HLA B27, ankylosing spondylitis, reactive arthritis, psoriatic arthritis. The abstracts for all studies meeting initial search criteria were reviewed; relevant studies were included. No prospective studies were found; however, four retrospective case studies were identified that examined LASIK surgery in patients with CVD. Several case reports were also identified in similar fashion.

RESULTS

The FDA considers CVD a relative contraindication to LASIK surgery, due largely to the ocular complications associated with disease in the CVD spectrum. However, recent studies of LASIK in patients with CVD indicate LASIK may be safe for patients with very well-controlled systemic disease, minimal ocular manifestations, and no clinical signs or history of dry-eye symptoms.

CONCLUSION

LASIK surgery may be safe in patients with rheumatoid arthritis or systemic lupus erythematosus and the seronegative spondyloarthropathies if stringent preoperative criteria are met. Evidence suggests patients with Sjögren's syndrome are not suitable candidates for LASIK.

Simultaneous positivity for anti-DNA, anti-nucleosome and anti-histone antibodies is a marker for more severe lupus nephritis

OBJECTIVE

The purpose of this study is to examine autoantibody profile of systemic lupus erythematosus (SLE) patients with lupus nephritis (LN) and to establish the correlation between the antibody reactivity and disease activity of LN.

METHODS

Autoantibodies and serological parameters were measured and analyzed in 589 SLE patients. The associations of the co-positivity of anti-dsDNA, -nucleosome and -histone antibodies (3-pos) with clinical, serological and outcome parameters were analyzed.

RESULTS

At the study entry, the prevalence for anti-dsDNA (61.52 % vs. 34.11 %, P < 0.0001), anti-nucleosome (56.09 % vs. 37.21 %, P = 0.0002) and anti-histone (49.35 % vs. 33.33 %, P = 0.0013) antibodies in patients with LN were significantly higher than that in patients without LN. Patients with 3-pos had a higher proportion of proliferative renal lesions (class III + IV). The incidence of a poor renal outcome (7.14 % vs. 2.52 %, P = 0.0174) in LN patients with 3-pos was significantly higher than those without 3-pos. Moreover, the rate of remission (73.63 % vs. 82.37 %, P = 0.0245) was significantly reduced and recurrence increased (58.90 % vs. 23.44 %, P < 0.0001) in 3-pos patients as compared to that in non 3-pos within the LN group.

CONCLUSION

Our data indicate a strong association between the 3-pos and renal disease activities, especially proliferative glomerulonephritis. The ability of 3-pos to predict renal flares may lead to major additional benefits in the follow-up of these patients.

Mannose binding lectin: a biomarker of systemic lupus erythematosus disease activity

Introduction

A role for mannose binding lectin (MBL) in autoimmune diseases has been demonstrated earlier and elevated level of MBL has been shown in systemic lupus erythematosus (SLE) patients. In the current study, we investigated MBL as a potential biomarker for disease activity in SLE.

Methods

In a case control study SLE patients (93 females) and 67 age, sex, ethnicity matched healthy controls were enrolled. Plasma MBL levels were quantified by enzyme linked immunosorbent assay (ELISA). Clinical, serological and other markers of disease activity (C3, C4 and anti-dsDNA) were measured by standard laboratory procedures.

Results

Plasma MBL levels were significantly high in SLE patients compared to healthy controls (P < 0.0001). MBL levels were variable in different clinical categories of SLE. Lower levels were associated with musculoskeletal and cutaneous manifestations (P = 0.002), while higher and intermediate MBL levels were significantly associated with nephritis in combination with other systemic manifestations (P = 0.01 and P = 0.04 respectively). Plasma MBL correlated with systemic lupus erythematosus disease activity index (SLEDAI) (P = 0.0003, r = 0.36), anti-dsDNA (P < 0.0001, r = 0.54), proteinuria (P < 0.0001, r = 0.42) and negatively correlated with C3 (P = 0.007, r = -0.27) and C4 (P = 0.01, r = -0.29).

Conclusions

Plasma MBL is a promising marker in the assessment of SLE disease activity.

Monocyte chemoattractant-1 as a urinary biomarker for the diagnosis of activity of lupus nephritis in Brazilian patients

OBJECTIVE

Monocyte chemotactic protein (MCP-1), involved in the pathogenesis of lupus nephritis (LN), has recently been indicated as a new biomarker of kidney activity in systemic lupus erythematosus (SLE). Our aim was to assess urinary MCP-1 (uMCP-1) as a biomarker of renal activity in patients with SLE and to compare it to other disease activity markers, using the ELISA.

METHODS

Seventy-five female Brazilian patients with SLE and a control group participated in our study. Patients with SLE were distributed among 3 groups according to kidney involvement and classified according to disease activity based on clinical and laboratory measures such as urinary sediment, proteinuria, kidney function, C3, C4, anti-dsDNA, disease activity index, and renal SLE disease activity index. The serum and uMCP-1 concentrations were measured by sandwich ELISA.

RESULTS

In the A-LN group (active lupus nephritis: SLE with kidney involvement), the concentration of uMCP-1 was significantly higher than in other groups. A cutoff point was established using the results of the control group to apply this test in the detection of LN. A-LN had a higher frequency of positive results for uMCP-1 in comparison to the other groups (p < 0.001). To detect disease activity in patients with LN, a new cutoff was determined based on the results of patients with SLE with kidney involvement. Setting specificity at 90%, the sensitivity of the test was 50%.

CONCLUSION

The high specificity makes uMCP-1 a useful test as a predictor of kidney activity in SLE, especially when associated to other measures used in clinical practice.

Biomarkers for systemic lupus erythematosus

In recent years, biomarkers have shown significant promise in helping decision-making in drug development. Systemic lupus erythematosus (SLE) is a complicated and highly heterogeneous disease that involves all organs. Only one drug, belimumab, has been approved by the US Food and Drug Administration to treat SLE during the last 50 years and there remains a high unmet medical need to develop new and effective therapies to benefit different patient populations in SLE. Due to the extreme heterogeneity of the disease and the complex and rigorous process to validate individual biomarkers, there is currently a very limited number of consensus biomarkers to aid the treatment decision-making in SLE. This review provides a snapshot of some biomarkers in the field that have the potential to make a big impact on drug development and/or treatment decisions by physicians. These include: type I interferon (IFN) gene signature as a pharmacodynamic marker and potential predictive marker for anti-type I IFN therapy; anti-double stranded DNA as a disease marker and potential predictive marker for flares; the complements and neutrophil signatures as disease marker of SLE; and TWEAK (a tumor necrosis factor family member produced by macrophages) and MCP-1 as potential markers to predict renal flares. Most of these markers need carefully planned and prospective studies with high statistical power to confirm their respective utilities. With the development and application of powerful new technologies, more successful biomarkers will emerge in SLE. This could improve the management of patients in the clinic and facilitate the development of novel and more effective therapeutics for this difficult-to-treat disease.

Circulating anti-double-stranded DNA antibody-secreting cells in patients with systemic lupus erythematosus: a novel biomarker for disease activity

Antibodies against double-stranded DNA (dsDNA) are widely used to diagnose systemic lupus erythematosus (SLE) and evaluate its activity in patients. This study was undertaken to examine the clinical utility of circulating anti-dsDNA antibody-secreting cells for evaluating SLE patients. Anti-dsDNA antibody-secreting cells quantified using an enzyme-linked immunospot assay were detected in the spleen, bone marrow and peripheral blood from MRL/ lpr but not in control BALB/c mice. Circulating anti-dsDNA antibody-secreting cells were detected in 29 (22%) of 130 patients with SLE, but in none of 49 with non-SLE connective-tissue disease or 18 healthy controls. The presence of circulating anti-dsDNA antibody-secreting cells was associated with persistent proteinuria, high SLE disease activity index and systemic lupus activity measures, and a high serum anti-dsDNA antibody titre measured with an enzyme-linked immunosorbent assay. The positive predictive value for active disease was 48% for circulating anti-dsDNA antibody-secreting cells versus 17% for serum anti-dsDNA antibodies. A prospective cohort of patients with circulating anti-dsDNA antibodies and inactive SLE showed that the cumulative disease flare-free rate was significantly lower in patients with than without circulating anti-dsDNA antibody-secreting cells ( p < 0.001). Circulating anti-dsDNA antibody-secreting cells are a useful biomarker for assessing disease activity in SLE patients.

Increased serum β2-microglobulin is associated with clinical and immunological markers of disease activity in systemic lupus erythematosus patients

The objective of this study was to explore the relationship between serum levels of β2-microglobulin (β2MG), which some studies suggest reflect disease activity in systemic lupus erythematosus (SLE), and various clinical and immunological markers of disease activity in SLE. Twenty-six SLE patients and 10 healthy controls were included. Disease activity was assessed by: SLEDAI, 24 hr-proteinuria, circulating levels of complement C3, anti-double-stranded DNA (anti-dsDNA), β2MG and various pro-inflammatory and anti-inflammatory cytokines (IL-6, IL-8, IL-10, IL-18) measured with a multiplex assay, IFN-α assessed with a reporter gene assay, and a combined expression score of 12 IFN-α inducible genes in peripheral blood mononuclear cells.

Median serum levels of β2MG were significantly higher in SLE patients vs controls (2.8 mg/L, range: 1.1–21.6 and 1.2 mg/L, range: 0.9–1.7, respectively, p < 0.001). β2MG was correlated with SLEDAI score ( R = 0.68, p < 0.001), 24 hr-proteinuria ( R = 0.64, p < 0.001), and complement C3 ( R = −0.52, p = 0.007). The cytokines were significantly correlated with β2MG: IL-6 ( R = 0.45, p = 0.02), IL-8 ( R = 0.75, p < 0.001), IL-10 ( R = 0.67, p < 0.001) and IL-18 ( R = 0.71, p < 0.001) as were serum IFN-α ( R = 0.45, p = 0.02) and the IFN-α inducible gene-score ( R = 0.51, p = 0.01). The results support that β2MG may serve as a marker of disease activity in SLE. The correlations with the measured cytokines indicate that increased β2MG in SLE reflects immunological activity.

Frequency of class III and IV nephritis in systemic lupus erythematosus without clinical renal involvement: an analysis of predictive measures

OBJECTIVE

To determine the frequency of International Society of Nephrology/Renal Pathology Society (ISN/RPS) class III or IV lupus nephritis in patients with systemic lupus erythematosus (SLE) without clinical renal involvement.

METHODS

We investigated the renal pathology of 195 patients with SLE, including 86 patients without clinical renal involvement.

RESULTS

Lupus nephritis other than class I was found in 58% of the patients without clinical renal involvement, and class III and IV nephritis was found in 15% of these patients. To reveal the predictive measures involved in class III or IV lupus nephritis, we explored the clinical measures in patients with SLE who did not have clinical renal involvement. Anti-dsDNA antibody titers were significantly higher (p = 0.0266) and C3 values were significantly lower (p = 0.0073) in patients with class III or IV lupus nephritis than in patients without class III or IV lupus nephritis. The sensitivity and specificity values were 77% and 73%, respectively, for cutoff levels of both 40 IU/ml for anti-dsDNA antibodies and 55 mg/dl for C3 (OR 8.8, p = 0.0011).

CONCLUSION

The frequency of nephritis, including ISN/RPS class III and IV, was unexpectedly high in SLE patients without clinical renal involvement. ISN/RPS class III or IV lupus nephritis could be hidden in patients with SLE who present both a high titer of anti-dsDNA antibody and a low concentration of C3, even when they have clinically normal urinary findings and renal function.

Anti-C1q antibodies have higher correlation with flares of lupus nephritis than other serum markers

OBJECTIVE

Autoantibodies are important in the diagnosis and classification of systemic lupus erythematosus (SLE), but whether they correlate with changes in disease activity within individual patients is controversial. We assessed the association between changes in SLE global and renal activity and changes in several autoantibodies and cell adhesion molecules in patients with SLE.

METHODS

Stored sera collected at two or three clinic visits from each of 49 SLE patients (91% female, 59% African-American, 31% Caucasian, 10% other ethnicity, 38% under 30 years, 41% between 30-44 years, and 21% 45-63 years) were analyzed. The visits were chosen to include one visit with proteinuria, and one or two without, for each patient. Global disease activity was measured by the Physician's Global Assessment (PGA), SELENA-SLEDAI (SLE Disease Activity Index modified to exclude anti-dsDNA and complement) and renal activity assessed by urine protein (by urine dipstick) and Renal Activity Score. Sera were assayed for anti-C1q, anti-chromatin, anti-dsDNA, anti-ribosomal P, monocyte chemotactic protein-1 (MCP-1), vascular cell adhesion molecule (VCAM) intercellular adhesion molecule (ICAM) and complement. The associations between changes in disease activity and changes in biomarker levels were assessed.

RESULTS

In terms of global disease activity, anti-C1q had the highest association with the PGA (p = 0.09) and was strongly associated with modified SELENA-SLEDAI (p = 0.009). In terms of renal activity, anti-C1q had the highest association with proteinuria (p = 0.079), and was strongly associated with Renal Activity Score (p = 0.006).

CONCLUSION

Anti-C1q performed the best of the potential biomarkers, being significantly associated with the modified SELENA-SLEDAI and with the Renal Activity Score. This study indicates the potential superior utility of anti-C1q over anti-dsDNA and other measures to track renal activity.

Correlation between Systemic Lupus Erythematosus Disease Activity Index, C3, C4 and Anti-dsDNA Antibodies

BACKGROUND

Therapeutic decisions in systemic lupus erythematosus (SLE) are based on the disease activity and nature of organ involvement. There are various clinical and laboratory methods to assess the lupus flares.

METHODS

Fifty one SLE patients with active disease (lupus flare) were studied. Systemic lupus erythematosus disease activity index (SLEDAI), C3, C4 and anti-double stranded DNA levels were estimated and repeated monthly till remission. After remission these tests were done three monthly. Values of serological parameters were then correlated with SLEDAI score.

RESULT

Thirteen (25.4%) patients had predominantly renal involvement while 38 (74.6%) patients had non-renal affliction. Musculoskeletal and mucocutaneous symptoms were the commonest features of lupus flare (90%). It was observed that 12 out of 13 (92.3%) patients with active renal involvement had low C3 levels and 11 (84.6%) had low C4 levels. The anti-dsDNA levels were elevated in all patients with predominant renal flare. In non-renal flare anti-dsDNA titre was raised only in 35% cases. Low C3 and C4 levels were noticed in 43% and 53% of non-renal flares respectively. Significant positive correlation was noticed between SLEDAI score and anti-dsDNA levels (0.01 level two-tailed prediction) and a significant negative correlation was observed with SLEDAI and C3, C4 levels (0.01 and 0.05 levels, two-tailed prediction) in our patients. On subgroup analysis it was noticed that this correlation is stronger for renal lupus. Negative correlation of SLEDAI and complement levels was not observed in non-renal flares.

CONCLUSION

Calculation of SLEDAI is a vital clinical tool for assessment of SLE patients. Serial estimation of anti-dsDNA titre, C3 and C4 levels help us diagnose lupus flare and make appropriate therapeutic decisions in patients with high SLEDAI score.

Efficacy and safety of belimumab in patients with active systemic lupus erythematosus: a randomised, placebo-controlled, phase 3 trial

BACKGROUND

Systemic lupus erythematosus is a heterogeneous autoimmune disease that is associated with B-cell hyperactivity, autoantibodies, and increased concentrations of B-lymphocyte stimulator (BLyS). The efficacy and safety of the fully human monoclonal antibody belimumab (BLyS-specific inhibitor) was assessed in patients with active systemic lupus erythematosus.

METHODS

Patients (aged ≥18 years) who were seropositive with scores of at least 6 on the Safety of Estrogens in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) were enrolled in a multicentre phase 3 study, which was done in Latin America, Asia-Pacific, and eastern Europe. Patients were randomly assigned by use of a central interactive voice response system in a 1:1:1 ratio to belimumab 1 mg/kg or 10 mg/kg, or placebo by intravenous infusion in 1 h on days 0, 14, and 28, and then every 28 days until 48 weeks, with standard of care. Patients, investigators, study coordinators, and sponsors were masked to treatment assignment. Primary efficacy endpoint was improvement in the Systemic Lupus Erythematosus Responder Index (SRI) at week 52 (reduction ≥4 points in SELENA-SLEDAI score; no new British Isles Lupus Assessment Group [BILAG] A organ domain score and no more than 1 new B organ domain score; and no worsening [<0·3 increase] in Physician's Global Assessment [PGA] score) versus baseline. Method of analysis was by modified intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00424476.

FINDINGS

867 patients were randomly assigned to belimumab 1 mg/kg (n=289) or 10 mg/kg (n=290), or placebo (n=288). 865 were treated and analysed in the belimumab (1 mg/kg, n=288; 10 mg/kg, n=290) and placebo groups (n=287). Significantly higher SRI rates were noted with belimumab 1 mg/kg (148 [51%], odds ratio 1·55 [95% CI 1·10-2·19]; p=0·0129) and 10 mg/kg (167 [58%], 1·83 [1·30-2·59]; p=0·0006) than with placebo (125 [44%]) at week 52. More patients had their SELENA-SLEDAI score reduced by at least 4 points during 52 weeks with belimumab 1 mg/kg (153 [53%], 1·51 [1·07-2·14]; p=0·0189) and 10 mg/kg (169 [58%], 1·71 [1·21-2·41]; p=0·0024) than with placebo (132 [46%]). More patients given belimumab 1 mg/kg (226 [78%], 1·38 [0·93-2·04]; p=0·1064) and 10 mg/kg (236 [81%], 1·62 [1·09-2·42]; p=0·0181) had no new BILAG A or no more than 1 new B flare than did those in the placebo group (210 [73%]). No worsening in PGA score was noted in more patients with belimumab 1 mg/kg (227 [79%], 1·68 [1·15-2·47]; p=0·0078) and 10 mg/kg (231 [80%], 1·74 [1·18-2·55]; p=0·0048) than with placebo (199 [69%]). Rates of adverse events were similar in the groups given belimumab 1 mg/kg and 10 mg/kg, and placebo: serious infection was reported in 22 (8%), 13 (4%), and 17 (6%) patients, respectively, and severe or serious hypersensitivity reactions on an infusion day were reported in two (<1%), two (<1%), and no patients, respectively. No malignant diseases were reported.

INTERPRETATION

Belimumab has the potential to be the first targeted biological treatment that is approved specifically for systemic lupus erythematosus, providing a new option for the management of this important prototypic autoimmune disease.

FUNDING

Human Genome Sciences and GlaxoSmithKline.

Anti-dsDNA-NcX ELISA: dsDNA-loaded nucleosomes improve diagnosis and monitoring of disease activity in systemic lupus erythematosus

INTRODUCTION

The objective of this study was to compare the clinical usefulness of the new anti-double-stranded DNA nucleosome-complexed enzyme-linked immunosorbent assay (Anti-dsDNA-NcX ELISA), which is based on dsDNA-loaded nucleosomes as antigens, with established test systems based on dsDNA or nucleosomes alone for systemic lupus erythematosus (SLE) diagnostics and determination of disease activity.

METHODS

Sera from a cohort of 964 individuals comprising 207 SLE patients, 357 disease controls and 400 healthy donors were investigated using the Anti-dsDNA-NcX ELISA, Farr assay, Anti-dsDNA ELISA, Anti-nucleosome ELISA and Crithidia luciliae immunofluorescence (CLIF) assay, all of which are tests available from EUROIMMUN Medizinische Labordiagnostika AG (Lübeck, Germany). Receiver operating characteristic curve analyses were performed to compare the sensitivity and specificity of each assay. The test results yielded by these assays in a group of 165 fully characterized SLE patients were compared with the corresponding medical records.

RESULTS

The Anti-dsDNA-NcX ELISA was found to have a sensitivity of 60.9% and a specificity of 98.9% in all 964 individuals at the manufacturer's cutoff of 100 U/ml. At a comparable specificity of 99%, the sensitivity amounted to 59.9% for the Anti-dsDNA-NcX ELISA, 54.1% for the Farr assay, 53.6% for the antinucleosome ELISA and 35.8% for the anti-dsDNA ELISA. The CLIF assay had a sensitivity of 28.0% and a specificity of 98.2%. The Anti-dsDNA-NcX ELISA correlated mostly with global disease activity in a cross-sectional analysis. In a longitudinal analysis of 20 patients with 69 patient visits, changes in Anti-dsDNA-NcX ELISA and antinucleosome ELISA results correlated highly with changes in disease activity over time.

CONCLUSIONS

The use of dsDNA-complexed nucleosomes as antigens in ELISA leads to optimized determination of diagnosis and disease activity in SLE patients and is available for clinical practice.

Improvement in health-related quality of life in patients with SLE following sustained reductions in anti-dsDNA antibodies

Patients with systemic lupus erythematosus experience a decreased health-related quality of life due to disease activity, multisystem organ involvement and frequent hospitalization. High levels of anti-double-stranded DNA antibodies are associated with renal disease, a primary cause of morbidity and mortality in systemic lupus erythematosus, and progressive cognitive dysfunction. Post hoc analyses of two clinical trials of abetimus sodium identified responders with sustained reductions in anti-double-stranded DNA antibodies. At 6 and 12 months, responders reported improvement in health-related quality of life, as measured by the Medical Outcomes Survey Short Form 36, compared with no change or deterioration in nonresponders. Sustained reductions in anti-double-stranded DNA antibodies, regardless of treatment group, led to clinically meaningful improvements in patient-reported health-related quality of life.

Prolonged Serologically Active Clinically Quiescent Systemic Lupus Erythematosus: Frequency and Outcome

Objective.

Some patients with systemic lupus erythematosus (SLE) are clinically quiescent despite persistent serologic activity. We determined the frequency of serologically active clinically quiescent (SACQ) SLE and its outcomes in prospectively followed patients with SLE.

Methods.

Patients with SLE followed between July 1970 and April 2008 with visits ≤ 18 months apart were identified. SACQ was defined as a ≥ 2-year sustained period without clinical activity with persistent serologic activity (increased anti-dsDNA and/or hypocomplementemia), during which antimalarials but neither steroids nor immunosuppressives were permissible. Characteristics of patients with an SACQ period and its features were analyzed. To determine flare predictors, anti-dsDNA and complement levels in SACQ patients who experienced flare were compared to levels in those who did not. Descriptive statistics were used; comparisons were made using t tests and chi-squared tests.

Results.

Of the patients studied, 56/924 (6.1%) were SACQ. They differed significantly from the non-SACQ SLE population only in the presenting SLE Disease Activity Index 2000 (7.34 vs 10.1 in non-SACQ), and frequency of steroid use (33.9% vs 60.8% in non-SACQ) and immunosuppressive use (3.6% vs 19.4% in non-SACQ) at first visit. Median SACQ period was 158 weeks. Thirty-three (58.9%) patients who were SACQ experienced flare (at median 155 weeks), 6 (10.7%) became clinically and serologically quiescent (236 weeks), and 17 continued to be SACQ (159 weeks). Common flare manifestations were arthritis, mucous membrane involvement, and sterile pyuria. Fluctuations in anti-dsDNA or complement levels did not predict flare.

Conclusion.

Fifty-nine percent of SACQ patients experienced flare, but after a median of 3 years. Fluctuations in complement and anti-dsDNA levels did not predict flare, thus treatment decisions in these patients must rely upon close clinical observation. Alternative predictive biomarkers warrant study.

The use of laboratory methods in differential diagnosis and treatment of SLE and antiphospholipid syndrome

The detection of autoantibodies has become an important component in the diagnosis and management of systemic lupus erythematosus (SLE) and antiphospholipid syndrome. Their importance lies in the fact that they are not only markers of the disease and used as part of a diagnostic panel, but many of them also show correlation with disease activity. All antibody testing should be interpreted in the context of the clinical features. The antinuclear antibodies test is an effective screening assay in patients with clinical features of SLE. The combination of antinuclear antibodies test, dsDNA and ENA (Ro, La, Sm, RNP) antibodies help to establish the diagnosis of most patients with SLE. New antibodies, such as antinucleosomes and anti-C1q, appear to be useful for SLE diagnosis, monitoring disease activity and predicting renal flares, particularly in dsDNA-negative patients. Anticardiolipin antibodies and lupus anticoagulant are the tests most commonly used in the diagnosis of antiphospholipid syndrome. However, the use of anti-beta(2)-glycoprotein I as a routine diagnostic test remains controversial.

Predictors of the rate of change in disease activity over time in LUMINA, a multiethnic US cohort of patients with systemic lupus erythematosus: LUMINA LXX

The objectives of the present study were (1) to clarify and quantify the relationship between age and disease duration with the rate of change in disease activity over time in patients with systemic lupus erythematosus (SLE) and (2) to explore other possible factors associated with this rate of change. To this end, SLE patients from LUMINA were studied if they had at least three visits in which disease activity (Systemic Lupus Activity Measure-Revised [SLAM-R]) had been ascertained. Variables associated with the rate (slope) of change in disease activity (obtained by regressing the SLAM-R score against the length of time from diagnosis to visit date) were examined by univariable and multivariable analyses. Five hundred and forty two of the 632 patients had at least three SLAM-R score. In multivariable analyses, Whites exhibited the fastest decline in disease activity, Texan Hispanics exhibited the slowest, trailed by the African Americans. Longer disease duration and HLA-DRB1*1503 positivity were associated with a slower decline whereas a greater number of American College of Rheumatology criteria and abnormal laboratory parameters (white blood cell counts, hematocrit and serum creatinine) were associated with a faster decline. These findings complement existing knowledge on SLE disease activity and are potentially useful to clinicians managing these patients.

SLE disease patterns in a Danish population-based lupus cohort: an 8-year prospective study

In 1995 all systemic lupus erythematosus (SLE) patients in the county of Funen were retrieved from four separate and independent sources as part of an 8-year prospective study to determine the pattern of disease activity and damage accumulation in a community based lupus cohort of predominantly Scandinavian ancestry. Incident cases were subsequently identified by surveillance of these sources. Established and new cases underwent annual, structured interviews, clinical examination and blood sampling. The Systemic Lupus Erythematosus Diseases Activity Index SLEDAI and Systemic Lupus International Collaborating Clinics SLICC scores were calculated. Flares were defined as modified — SLEDAI ≥ 4.

The annual flare rate in definite SLE (D-SLE) was 0.21 (95%CI 0.18—0.24) versus 0.03 (95%CI 0.01—0.07) in incomplete SLE (I-SLE). Forty-three per cent of the entire study population had no disease exacerbations. Infections requiring hospital admission and thrombocytopenia were significantly more frequent among patients with relapsing disease (p < 0.04—0.01). Patients with flares had slightly shorter disease duration and were younger at disease onset than patients with a quiescent course. The most recently diagnosed patients had the lowest annual rate of damage accrual.

According to flare rate, two major subsets of almost equal size were identified — one having a long quiescent course, the other exhibiting relapses alternating with remissions. An increased risk of flares was associated with short disease duration and younger age at disease onset, infections requiring hospital admission and thrombocytopenia. Temporal damage increment was the lowest in the most recently diagnosed patients. Lupus (2010) 19, 239—246.

Interferon-regulated chemokines as biomarkers of systemic lupus erythematosus disease activity: a validation study

OBJECTIVE

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by unpredictable flares of disease activity and irreversible damage to multiple organ systems. An earlier study showed that SLE patients carrying an interferon (IFN) gene expression signature in blood have elevated serum levels of IFN-regulated chemokines. These chemokines were associated with more-severe and active disease and showed promise as SLE disease activity biomarkers. This study was designed to validate IFN-regulated chemokines as biomarkers of SLE disease activity in 267 SLE patients followed up longitudinally.

METHODS

To validate the potential utility of serum chemokine levels as biomarkers of disease activity, we measured serum levels of CXCL10 (IFNgamma-inducible 10-kd protein), CCL2 (monocyte chemotactic protein 1), and CCL19 (macrophage inflammatory protein 3beta) in an independent cohort of 267 SLE patients followed up longitudinally over 1 year (1,166 total clinic visits).

RESULTS

Serum chemokine levels correlated with lupus activity at the current visit (P = 2 x 10(-10)), rising at the time of SLE flare (P = 2 x 10(-3)) and decreasing as disease remitted (P = 1 x 10(-3)); they also performed better than the currently available laboratory tests. Chemokine levels measured at a single baseline visit in patients with a Systemic Lupus Erythematosus Disease Activity Index of < or =4 were predictive of lupus flare over the ensuing year (P = 1 x 10(-4)).

CONCLUSION

Monitoring serum chemokine levels in SLE may improve the assessment of current disease activity, the prediction of future disease flares, and the overall clinical decision-making.

Correlation between clinical activity and serological markers in a wide cohort of patients with systemic lupus erythematosus: an eight-year prospective study

Titers of serum anti-double-stranded DNA antibodies (anti-dsDNA Abs) and C3 and C4 are used for monitoring systematic lupus erythematosus (SLE) patients. Here, we assessed the relationship between the clinical activity index (SLEDAI) and serum titers of anti-dsDNA Abs, C3, and C4 in an 8-year prospective study conducted in 194 SLE patients. The association of anti-dsDNA Abs and complement with M-SLEDAI was significant but low. Ninety-eight of the 194 patients were selected because they were followed for at least 5 years. We observed four types of clinical-serological patterns: parallelism between serum and clinical activity (n = 24), clinical quiescence with partial serum activity (n = 30), clinical quiescence but serologically fully active (n = 18), and clinical activity but serologically quiescent (n = 21). The serological markers evaluated are of limited utility in the monitoring of SLE patients and their use must be individualized.

Neutrophil gelatinase-associated lipocalin is a predictor of the course of global and renal childhood-onset systemic lupus erythematosus disease activity

OBJECTIVE

To determine whether neutrophil gelatinase-associated lipocalin (NGAL) can predict worsening of global and renal disease activity in childhood-onset systemic lupus erythematosus (SLE).

METHODS

One hundred eleven patients with childhood-onset SLE were enrolled in a longitudinal, prospective study with quarterly study visits and had at least 3 study visits. At each visit, global disease activity was measured using 3 external standards: the numerically converted British Isles Lupus Assessment Group (BILAG) index, the SLE Disease Activity Index 2000 update score, and the physician's assessment of global disease activity. Renal and extrarenal disease activity were measured by the respective domain scores. The disease course over time was categorized at the most recent visit (persistently active, persistently inactive, improved, or worsening). Plasma and urinary NGAL levels were measured by enzyme-linked immunosorbent assay, and urinary NGAL levels were standardized to the urinary creatinine concentration. The longitudinal changes in NGAL levels were compared with the changes in SLE disease activity using mixed-effect models.

RESULTS

Significant increases in standardized urinary NGAL levels of up to 104% were detected up to 3 months before worsening of lupus nephritis (as measured by all 3 external standards). Plasma NGAL levels increased significantly by as much as 26% up to 3 months before worsening of global SLE disease activity as measured by all 3 external standards. Plasma NGAL levels increased significantly by 26% as early as 3 months prior to worsening of lupus nephritis as measured by the BILAG renal score.

CONCLUSION

Serial measurement of urinary and plasma NGAL levels may be valuable in predicting impending worsening of global and renal childhood-onset SLE disease activity.

The impact of flare on disease costs of patients with systemic lupus erythematosus

OBJECTIVE

To evaluate both direct and indirect costs of systemic lupus erythematosus (SLE) patients with and without flares from a societal perspective, and to investigate the impact of the severity and clinical manifestations of flares on direct/indirect costs.

METHODS

A retrospective cost-of-illness study was performed on 306 SLE patients. Participants completed questionnaires on sociodemographics, employment status, and out-of-pocket expenses. Health resources consumption was recorded by chart review and patient self-reported questionnaire. The total number of flares and involved organs during the preceding 12 months were recorded. Multiple linear regression was performed to determine the cost predictors.

RESULTS

Patients with flares were younger, had shorter disease duration, and had higher disease activity at the time of the assessment. The overall incidence of lupus flares was 0.24 episodes per patient-year. Patients with flares used more health care resources and incurred significantly higher annual direct and indirect costs. The mean total costs per patient-year were 2-fold higher for patients with flares ($22,580 versus $10,870 [2006 US dollars]; P < 0.0005). Multiple regression analysis showed that the number of flares was an independent explanatory variable associated with increased direct costs. Patients with multiorgan flares or renal/neuropsychiatric flares incurred higher direct costs compared with those with single-organ flares or with other organ flares.

CONCLUSION

Patients with flares incur higher direct and indirect costs compared with those without flares. Major organ flares incur higher disease costs than other organ flares. Treatments that effectively control disease activity and prevent flares, especially major organ flares, may reduce the high costs associated with flare in SLE.

Prevalence of flare and influence of demographic and serologic factors on flare risk in systemic lupus erythematosus: a prospective study

OBJECTIVE

We determined the prevalence of and risk factors for British Isles Lupus Activity Group (BILAG) flare in patients with systemic lupus erythematosus (SLE).

METHODS

We followed 299 patients for 1 year with the BILAG scores calculated using British Lupus Integrated Prospective System software and confirmed with manual calculation.

RESULTS

"A" flares occurred at a rate of 0.254/year, "B" flares 1.637/year, and A or B flares 1.765/year. The most common A flares were renal and mucocutaneous. The most common B flares were hematologic, renal, mucocutaneous, and musculoskeletal. Risk factors for a later A or B flare in the hematological system included: low C3 (p < 0.0001), low C4 (p = 0.0004), and positive anti-double-stranded (ds)DNA (p = 0.003); in the mucocutaneous system: low C3 (p = 0.02) and low C4 (p = 0.0004); and in the renal system: low C3 (p = 0.02) and low C4 (p = 0.02). In a stepwise regression model, only ethnicity (p = 0.02) and low C4 (p = 0.0002) remained as independent predictors of later A or 2B flares.

CONCLUSION

The organ system distribution of A and B flares is very different, with A flares more common in renal and mucocutaneous, and B flares more common in hematologic and renal systems. A or 2B flares are significantly more common in African Americans and in patients with abnormal serologies (low C3, low C4, or high anti-dsDNA). If flare is an outcome in an SLE clinical trial, these factors must be balanced by taking them into account at baseline in terms of randomization, or by statistical adjustment in final analyses.

Biomarkers for lupus nephritis: the quest continues

Current treatment of severe lupus nephritis is unsatisfactory in terms of both outcome and toxicity. To improve the efficacy and decrease the adverse effects of immunosuppression, it would be ideal to be able to predict the course and pathology of lupus nephritis and adjust therapy appropriately. This will require biomarkers that reflect disease activity. Recently, significant effort has been put into identifying biomarkers that can anticipate impending lupus renal flare, forecast development of chronic kidney disease, or reflect kidney histology at the time of flare. Although these biomarkers are potentially useful, to date none has been clinically validated in a large, prospective cohort of patients with SLE. This article reviews the current status of lupus nephritis biomarker investigation and articulates a perspective of how future efforts should be focused.

Urine osteoprotegerin and monocyte chemoattractant protein-1 in lupus nephritis

OBJECTIVE

Renal biopsy is the "gold standard" to determine renal activity in systemic lupus erythematosus (SLE), but it is expensive, invasive, and carries risk. Osteoprotegerin (OPG) is produced by the heart, lungs, kidney, and bone. Monocyte chemoattractant protein-1 (MCP-1), a chemotactic cytokine, is involved in the progression of glomerular and tubulointerstitial injury. We investigated both urine OPG and MCP-1 as potential biomarkers for lupus nephritis.

METHODS

Our subjects, 87 patients with SLE (88% women; 48% African American, 41% Caucasian, 11% other), mean age 44 years, were followed monthly to quarterly. Urinary OPG (pg/ml) and MCP-1 (pg/ml) were measured (Luminex MAP bead assay).

RESULTS

OPG concentrations were strongly associated with global disease activity and with both renal activity on a visual analog scale (VAS) (p = 0.0006) and renal disease activity descriptors of the SELENA SLEDAI, including hematuria (p = 0.001) and a positive anti-dsDNA (p = 0.013). MCP-1 was also associated with the renal VAS (p = 0.032), renal disease activity descriptors of SELENA SLEDAI, including hematuria (p = 0.027), and with a positive anti-dsDNA (p = 0.016). We also examined the relationship between the biomarkers and having a urine protein to creatinine ratio (pr/cr) > or = 0.5. Among patients with medium or high OPG, 46% had urine pr/cr > or = 0.5, compared to only 23% among those with low OPG (p = 0.032). The 2 biomarkers were strongly correlated with each other (Spearman correlation coefficient 0.77, p < 0.0001).

CONCLUSION

The lack of availability of urine biomarkers has hampered development of new therapies for lupus nephritis. Urine MCP-1 and OPG were both associated with measures of lupus renal disease activity. Medium or high levels of OPG were predictive of a urine protein/creatinine ratio of > or = 0.5. Further study, including longitudinal assessment and correlation with concurrent renal biopsies, is necessary before this assay can be used in the routine clinic setting.