Soluble Mediators as Therapeutic Targets in Systemic Lupus Erythematosus: Cytokines, Immunoglobulin Receptors, and the Complement System

Lipid anti-lipid antibody responses correlate with disease activity in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder characterized by broad clinical manifestations including cardiovascular and renal complications with periodic disease flares and significant morbidity and mortality. One of the main contributing factors to the pathology of SLE is the accumulation and impaired clearance of immune complexes of which the principle components are host auto-antigens and antibodies. The contribution of host lipids to the formation of these autoimmune complexes remains poorly defined. The aim of the present study was to identify and analyze candidate lipid autoantigens and their corresponding anti-lipid antibody responses in a well-defined SLE patient cohort using a combination of immunological and biophysical techniques. Disease monitoring in the SLE cohort was undertaken with serial British Isles Lupus Assessment Group (BILAG) scoring. Correlations between specific lipid/anti-lipid responses were investigated as disease activity developed from active flares to quiescent during a follow up period. We report a significant negative correlation between anti-lipid antibodies for 24S-hydroxycholesterol, cardiolipin and phosphatidylserine with SLE disease activity. Taken together, these data suggest that lipid autoantigens represent a new family of biomarkers that can be employed to monitor disease activity plus the efficacy of therapeutic intervention in SLE.

[Novel therapeutic possibilities in systemic lupus erythematosus]

Systemic lupus erythematosus (SLE) is an autoimmune disorder involving different organs and organ systems with consequent characteristic clinical and serologic symptoms. Despite of the improvement in lupus survival, approximately 10-20% of patients do not respond to traditional immune suppressive therapies. Relapses are more frequent; e.g. after cyclophosphamide therapy diffuse proliferative nephritis flares in 1/3 of patients. Different immune competent cells and inflammatory mediators participate in the pathogenesis of SLE involving both the adaptive and innate immunity. Several pathogenic elements and mechanisms may serve as therapeutic targets, consequently. Authors summarize novel therapeutic possibilities and their mechanisms regarding the pathogenesis of SLE. Immune modulation of B and T cells, co-stimulatory pathways, cytokine network, soluble mediators and autologous hemopoietic stem cell transplantation are discussed.

Cytokines and their receptors as biomarkers of systemic lupus erythematosus

Systemic lupus erythematosus is the most clinically diverse autoimmune disease. Owing to its heterogeneous presentation, clinical management of systemic lupus erythematosus remains as one of the greatest challenges. Therefore, there is a great need to assess disease activity accurately. Biomarkers can be objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes or pharmacologic responses to a therapeutic intervention, and may also predict the risk of the disease, confirm diagnosis, monitor disease activity and provide prognostic information. Cytokines play an important and diverse role in the immune dysregulation in systemic lupus erythematosus. Measuring serum levels of soluble IL-2 receptor, IL-6, IL-10, soluble TNF receptor and IFN-alpha/IFN-induced genes may be promising biomarkers of disease activity in systemic lupus erythematosus.

LJP-394 (abetimus sodium) in the treatment of systemic lupus erythematosus

Renal disease is one of the most severe aspects of systemic lupus erythematosus (SLE), potentially leading to irreversible kidney failure. The standard of care for severe lupus nephritis involves the use of high-dose corticosteroids, cyclophosphamide and other immunosuppressive drugs. Although these drugs are effective in controlling disease activity in the majority of patients, up to 25% of patients treated with cyclophosphamide-based protocols develop renal insufficiency and end-stage renal disease, and treatment discontinuation is associated with the occurrence of flares. Furthermore, these therapies are associated with a high incidence of short- and long-term side effects. LJP-394 (abetimus sodium) is an investigational agent specifically designed to decrease anti-dsDNA antibody levels, and it is under development for the prevention of nephritic flares in patients with SLE since the early 1990s. The drug has been evaluated in 13 clinical trials that evaluated > 800 patients with SLE, over a 10-year time span. It is likely that LJP-394 might have a role in the prevention of renal flares in SLE patients, and if the initial data is confirmed in an ongoing trial, this drug could represent either a substitute for immunosuppressive drugs or could allow a reduction of their dose, thereby reducing the risks of short- and long-term side effects. This paper reviews the principal aspects of chemistry, pharmacokinetics, efficacy and safety of LJP-394, and analyses studies on animal models and clinical studies conducted in the last few years.

Emerging drug therapies for systemic lupus erythematosus

Despite the tremendous improvement in survival of systemic lupus erythematosus (SLE) in the past few decades, manifestations of the disease that are refractory to conventional therapies and treatment-related complications are still major causes of mortality and morbidity. In recent years, we have seen an explosive development of newer therapeutic modalities for various rheumatic diseases including SLE. Novel therapies for SLE should aim at targeting more specifically the immunopathogenetic pathways to achieve higher efficacy and reduce therapy related toxicities. This article reviews the emerging therapeutic modalities that have been used or are being tried in patients with SLE.