Novel treatments for systemic lupus erythematosus

Anti-α-enolase antibody combined with β2 microglobulin evaluated the incidence of nephritis in systemic lupus erythematosus patients

OBJECTIVE

Anti-α-enolase antibody (Ab) combined with β2 microglobulin (β2-MG) were investigated to predict the incidence of nephritis in systemic lupus erythematosus (SLE) patients.

METHODS

Levels of serum anti-α-enolase Ab and urinary β2-MG were detected in 115 SLE patients, 29 SLE patients with nephritis and 70 healthy controls by ELISA and immunoturbidimetry, respectively. Furthermore, the correlation between anti-α-enolase Ab combined with β2-MG and the incidence of nephritis in SLE patients was evaluated by correlation analysis.

RESULTS

The optical density value of serum anti-α-enolase Ab in SLE patients with nephritis (0.84) was greatly increased compared with SLE patients (0.76) or healthy controls (0.54). Moreover, the levels of urinary β2-MG in SLE patients with nephritis (6.75 mg/L) were increased compared with SLE patients (3.45 mg/L) or healthy controls (1.48 mg/L). There was a positive correlation between the level of anti-α-enolase Ab and β2-MG ( r = 0.754). Furthermore, anti-α-enolase Ab combined with β2-MG for evaluating the incidence of nephritis in SLE patients had the best assessment of the effectiveness (area under the receiver operating characteristic curve (AUC): 92.7%) compared with only anti-α-enolase Ab (AUC: 80.9%) or β2-MG (AUC: 84.5%).

CONCLUSION

These data suggested that anti-α-enolase Ab may be a potential indicator for the prediction of nephritis in SLE patients.

Unmet Needs in the Pathogenesis and Treatment of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune rheumatic disease with a prevalence of approximately 1 in 1000. Over the last 30 years, advances in treatment such as use of corticosteroids and immunosuppressants have improved life expectancy and quality of life for patients with lupus and the key unmet needs have therefore changed. With the reduced mortality from disease activity, development of cardiovascular disease (CVD) has become an increasingly important cause of death in patients with SLE. The increased CVD risk in these patients is partly, but not fully explained by standard risk factors, and abnormalities in the immune response to lipids may play a role. Invariant natural killer T cells, which are triggered specifically by lipid antigens, may protect against progression of subclinical atherosclerosis. However, currently our recommendation is that clinicians should focus on optimal management of standard CVD risk factors such as smoking, blood pressure and lipid levels. Fatigue is one of the most common and most limiting symptoms suffered by patients with SLE. The cause of fatigue is multifactorial and disease activity does not explain this symptom. Consequently, therapies directed towards reducing inflammation and disease activity do not reliably reduce fatigue and new approaches are needed. Currently, we recommend asking about sleep pattern, optimising pain relief and excluding other causes of fatigue such as anaemia and metabolic disturbances. For the subgroup of patients whose disease activity is not fully controlled by standard treatment regimes, a range of different biologic agents have been proposed and subjected to clinical trials. Many of these trials have given disappointing results, though belimumab, which targets B lymphocytes, did meet its primary endpoint. New biologics targeting B cells, T cells or cytokines (especially interferon) are still going through trials raising the hope that novel therapies for patients with refractory SLE may be available soon.

Reduction of CD19 autoimmunity marker on B cells of paediatric SLE patients through repressing PU.1/TNF-α/BAFF axis pathway by miR-155

microRNA-155 (miR-155) is implicated in regulating B-cell activation and survival that is important in systemic lupus erythematosus (SLE) pathogenesis. PU.1, a target for miR-155, is a crucial regulator of B-cell development and enhances Tumour-Necrosis-factor-alpha (TNF-α) expression. TNF-α induces the expression of B-cell-activating-factor (BAFF). BAFF is reported to increase the expression of the autoimmunity marker; CD19. This study aimed to investigate the regulation of expression of PU.1 in pediatric-systemic-lupus-erythematosus (pSLE) patients by miR-155, and hence evaluate its impact on TNF-α/BAFF/CD19 signalling pathway. Screening revealed that PU.1 is upregulated in PBMCs and B-cells of pSLE patients. PU.1 expression directly correlated with systemic-lupus-erythematosus disease-activity-index-2 K SLEDAI-2K. Ectopic expression of miR-155 and knockdown of PU.1 suppressed PU.1, TNF-α and BAFF. Finally, miR-155 decreased the proportion of BAFF-expressing-B-cells and CD19 protein expression. These findings suggest that miR-155 suppresses autoimmunity through transcriptional repression of PU.1 and TNF-α, which in turn suppresses BAFF and CD19 protein expression.

RNA-seq Analysis Reveals Unique Transcriptome Signatures in Systemic Lupus Erythematosus Patients with Distinct Autoantibody Specificities

Systemic lupus erythematosus (SLE) patients exhibit immense heterogeneity which is challenging from the diagnostic perspective. Emerging high throughput sequencing technologies have been proved to be a useful platform to understand the complex and dynamic disease processes. SLE patients categorised based on autoantibody specificities are reported to have differential immuno-regulatory mechanisms. Therefore, we performed RNA-seq analysis to identify transcriptomics of SLE patients with distinguished autoantibody specificities. The SLE patients were segregated into three subsets based on the type of autoantibodies present in their sera (anti-dsDNA+ group with anti-dsDNA autoantibody alone; anti-ENA+ group having autoantibodies against extractable nuclear antigens (ENA) only, and anti-dsDNA+ENA+ group having autoantibodies to both dsDNA and ENA). Global transcriptome profiling for each SLE patients subsets was performed using Illumina® Hiseq-2000 platform. The biological relevance of dysregulated transcripts in each SLE subsets was assessed by ingenuity pathway analysis (IPA) software. We observed that dysregulation in the transcriptome expression pattern was clearly distinct in each SLE patients subsets. IPA analysis of transcripts uniquely expressed in different SLE groups revealed specific biological pathways to be affected in each SLE subsets. Multiple cytokine signaling pathways were specifically dysregulated in anti-dsDNA+ patients whereas Interferon signaling was predominantly dysregulated in anti-ENA+ patients. In anti-dsDNA+ENA+ patients regulation of actin based motility by Rho pathway was significantly affected. The granulocyte gene signature was a common feature to all SLE subsets; however, anti-dsDNA+ group showed relatively predominant expression of these genes. Dysregulation of Plasma cell related transcripts were higher in anti-dsDNA+ and anti-ENA+ patients as compared to anti-dsDNA+ ENA+. Association of specific canonical pathways with the uniquely expressed transcripts in each SLE subgroup indicates that specific immunological disease mechanisms are operative in distinct SLE patients' subsets. This 'sub-grouping' approach could further be useful for clinical evaluation of SLE patients and devising targeted therapeutics.

A fully human monoclonal antibody with novel binding epitope and excellent neutralizing activity to multiple human IFN-α subtypes: A candidate therapy for systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic, heterogeneous autoimmune disease short of effective therapeutic agents. A multitude of studies of SLE in the last decade have accentuated a central role of the interferon alpha (IFN-α) pathway in SLE pathogenesis. We report here a candidate therapeutic neutralizing antibody, AIA22, with a different binding epitope and discrepant neutralizing profile from the anti-multiple IFN-α subtype antibodies currently in clinical trials. AIA22 specifically interacts with multiple IFN-α subtypes, binds to the type I IFN receptor 2 (IFNAR2) recognition region of IFN-α (considered a novel antigen epitope), and effectively neutralizes the activity of almost all of the IFN-α subtypes (with the exception of IFN-α7) both in vitro and in vivo. Concurrently, structural modeling and computational design yielded a mutational antibody of AIA22, AIAmut, which exhibited substantially improved neutralizing activity to multiple IFN-α subtypes.

New therapeutic avenues in SLE

Although the use of corticosteroids and immunosuppressive agents such as cyclophosphamide and mycophenolate has led to reduced mortality in systemic lupus erythematosus (SLE), there is a need for development of new biologic agents to improve outcomes further. The pathogenesis of SLE involves many components of the immune system, notably B cells, T cells, cytokines and innate immunity, which are potential targets for the new biologic therapies. In this study, the rationale for the development of new therapies in SLE and the progress that has been made in each direction of therapy are described. Most progress has been made with agents directed against B cells, especially rituximab and belimumab and the latter has been the subject of two successful randomised clinical trials (RCTs). Anti-T-cell and anti-cytokine therapies are further back in the development process, but promising advances can be anticipated over the next decade.

Drugs in early clinical development for Systemic Lupus Erythematosus

INTRODUCTION

While immunosuppressive therapy has positively impacted the prognosis of systemic lupus erythematosus (SLE), many patients still do not respond to traditional therapy. Thus, active SLE disease remains a significant problem. Furthermore, conventional immunosuppressive treatments for SLE are associated a high risk of side effects. These issues call for improvement in our current therapeutic armamentarium.

AREAS COVERED

In this review, the authors highlight the recent developments in therapies for SLE, and present an overview of drugs which are in early clinical development for SLE. There are many new therapeutic approaches being developed, including those focused on B-cell targets, T-cell downregulation, co-stimulatory blockade, anti-cytokine agents, and kinase inhibition, and Toll-like receptor inhibition. They also discuss peptide therapy as a potential method to re-establish immune tolerance, and some of the challenges ahead in developing and testing novel agents for SLE.

EXPERT OPINION

Many novel agents are currently in development for SLE, but this encouraging news is tempered by several disappointments in clinical trials and provides a timely moment to reflect on the future of therapeutic development in SLE. It seems likely that biological heterogeneity between patients is a major contributor to difficulty in drug design in SLE.

Recent developments in the treatment of patients with systemic lupus erythematosus: focusing on biologic therapies

INTRODUCTION

Major trials hoping to obtain optimal disease control in systemic lupus erythematosus (SLE) are ongoing. Given its complex aetiology and pathogenesis, it is not surprising that multiple therapeutic targets have emerged and that none are uniformly successful.

AREAS COVERED

In this review, we highlight the recent, more significant studies focusing on the use of biologic therapies. There has been great emphasis on the role of B cells in SLE and many uncontrolled studies have encouraged the use of rituximab (an anti-CD20 monoclonal). Disappointingly, two major trials, EXPLORER and LUNAR did not confirm its utility, although doubts have been expressed on their trial design, and other trials using this drug are commencing. In contrast, belimumab, which blocks a B-cell activating factor, did meet its end points in two major randomised controlled clinical trials and has been approved for use in SLE by both the FDA and the European Medicines Agency. Encouraging, albeit preliminary, results with epratuzumab (which blocks CD22) have also been reported.

EXPERT OPINION

In addition to targeting B cells, other approaches including biologics, which modulate T-cell function and block interleukin-6 and interferon-α, have been explored. Finally, we review the recent developments in the use of conventional drugs, such as cyclophosphamide and mycophenolate.