Novel Approaches to Therapy for SLE

Efficacy and safety of Janus kinase inhibitors in systemic and cutaneous lupus erythematosus: A systematic review and meta-analysis

BACKGROUND

Janus kinase (JAK) inhibitors have been proven to be effective and safe in various autoimmune diseases. However, there is still a lack of comprehensive evidence regarding their efficacy and safety in systemic and cutaneous lupus erythematosus.

METHODS

We searched for systemic and cutaneous lupus erythematosus patients who were treated with JAK inhibitors in PubMed, Embase, Web of Science, and the Cochrane Library until February 28, 2023. The quality of clinical trials was assessed using the Cochrane risk-of-bias tool. Meta-analysis was conducted when at least three studies had comparable measures of outcome. If meta-analysis was not feasible, a descriptive review was carried out.

RESULTS

We included 30 studies, consisting of 10 randomized controlled trials and 20 case series or reports, with a total of 2,460 patients. JAK inhibitors were found to be more effective than placebo in systemic lupus erythematosus (SLE) based on the percentage of achieving SLE Responder Index (SRI)-4 response (RR = 1.18; 95% CI 1.07 to 1.31; p = 0.001), British Isles Lupus Assessment Group -based Composite Lupus Assessment (BICLA) response (RR = 1.16; 95% CI 1.02 to 1.31; p = 0.02), Lupus Low Disease Activity State (LLDAS) (RR = 1.28; 95% CI 1.07 to 1.54; p = 0.008), and Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2 K) remission of arthritis or rash (RR = 1.09; 95% CI 1.00 to 1.18; p = 0.04), particularly in treating musculoskeletal and mucocutaneous involvement. However, the effect of JAK inhibitors on cutaneous lupus erythematosus was uncertain. JAK inhibitors and placebo had a similar incidence of adverse events (RR = 1.01; 95% CI 0.97 to 1.04; p = 0.65).

CONCLUSION

JAK inhibitors could be a potential treatment option for systemic and cutaneous lupus erythematosus, particularly in treating cutaneous and musculoskeletal lesions of SLE. JAK inhibitors had a safe profile.

Targeting IL-10 in auto-immune diseases

IL-10 is a multifunctional cytokine secreted by a variety of cells. It not only inhibits activation of monocyte/macrophage system and synthesis of monocyte cytokine and inflammatory cytokine but also promotes the proliferation and maturation of non-monocyte-dependent T cell, stimulating proliferation of antigen-specific B cell. Increasing evidence indicates that IL-10 plays an important role in both the onset and development of auto-immune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjogren's syndrome (SS), multiple sclerosis (MS), Crohn's disease (CD), and psoriasis. However, the exact mechanisms of IL-10 in auto-immune diseases remain unclear. In the present review, we will summarize the biological effects of IL-10, as well as its role and therapeutic potential in auto-immune diseases.

VGX-1027 modulates genes involved in lipopolysaccharide-induced Toll-like receptor 4 activation and in a murine model of systemic lupus erythematosus

VGX-1027 [(S,R)-3-phenyl-4,5-dihydro-5-isoxasole acetic acid] is a small molecule compound with immunomodulatory properties, which favourably influences the development of immuno-inflammatory and autoimmune diseases in different animal models such as type 1 diabetes mellitus, pleurisy, rheumatoid arthritis and inflammatory bowel disease. However, the precise mechanism of action of VGX-1027 remains to be ascertained. With this aim, we have studied the immunomodulatory effects of VGX-1027 in vitro, using a genome-wide oligonucleotide microarray approach, and in vivo, using the NZB/NZW F1 model of systemic lupus erythematosus. Microarray data revealed that the administration of VGX-1027 profoundly affected the immune response to exogenous antigens, by modulating the expression of genes that are primarily involved in antigen processing and presentation as well as genes that regulate immune activation. When administered in vivo VGX-1027 ameliorated the course of the disease in the NZB/NZW F1 mice, which correlated with higher per cent survival and improved clinical and histopathological signs. The data presented herein support the theory that VGX-1027 modulates immunity, probably by inhibiting inflammatory antigen presentation and so limiting immune cell expansion.

Why can't we find a new treatment for SLE?

No new therapy for systemic lupus erythematosus has been approved. In the last decade, the development of several novel compounds has been pursued for lupus, but so far nothing has been proven to be effective. This review discusses some of the reasons why it may be so difficult to demonstrate that a novel therapy is effective for this disease. These include the complexity of the disease itself; the lack of reliable outcome measures; our limited understanding of the pathogenesis of the disease; the propensity of lupus patients to have bad outcomes and to react to medicines in unusual ways; the heterogeneity of the patient population; the unpredictable course of disease in individual patients; and the lack of reliable biomarkers. Although some of the tested targeted compounds that are apparently based on strong preclinical and mechanistic data may indeed not be effective therapies for SLE, it is hard not to believe that among the various specific agents now being tested that at least some of them should downregulate the abnormal immunoregulation characteristic of SLE, and thus be clinically effective. We need to be persistent and imaginative in identifying these effective agents and proving their efficacy so that they may be widely used in our lupus populations.

Nuclear factor of activated T cells (NFAT) mediates CD154 expression in megakaryocytes

Platelets are an abundant source of CD40 ligand (CD154), an immunomodulatory and proinflammatory molecule implicated in the onset and progression of several inflammatory diseases, including systemic lupus erythematosus (SLE), diabetes, and cardiovascular disease. Heretofore considered largely restricted to activated T cells, we initiated studies to investigate the source and regulation of platelet-associated CD154. We found that CD154 is abundantly expressed in platelet precursor cells, megakaryocytes. We show that CD154 is expressed in primary human CD34+ and murine hematopoietic precursor cells only after cytokine-driven megakaryocyte differentiation. Furthermore, using several established megakaryocyte-like cells lines, we performed promoter analysis of the CD154 gene and found that NFAT, a calcium-dependent transcriptional regulator associated with activated T cells, mediated both differentiation-dependent and inducible megakaryocyte-specific CD154 expression. Overall, these data represent the first investigation of the regulation of a novel source of CD154 and suggests that platelet-associated CD154 can be biochemically modulated.

B cell targeted therapy in autoimmunity

Autoimmunity results from a break in self-tolerance involving humoral and/or cell-mediated immune mechanisms. Part of the pathological consequence of a failure in central and/or peripheral tolerance, results from survival and activation of self-reactive B cells. Such B cells produce tissue-damaging pathogenic autoantibodies, and subsequent formation of complement-fixing immune complexes that contribute to tissue damage. Current pharmacological strategies for treating autoimmune diseases involve global use of broad-acting immunosuppressants that with long term use have associated toxicities. The present drive in drug development is towards therapies that target a specific biological pathway or pathogenic cell population. This review focuses on some of the emerging therapies based on co-stimulation blockers, and compounds which contribute to a specific B cells depletion, based on studies in animal models and human clinical studies.

B cells move to centre stage: novel opportunities for autoimmune disease treatment

The B-cell arm of the immune system has long been appreciated for its crucial role in pathogen resistance, but in the study of many autoimmune diseases, T cells have dominated the limelight for decades. However, the development of the B-cell-depleting antibody rituximab as a lymphoma therapy has provided a tool to probe the contribution made by B cells in several immune disorders. Recently, the success of B-cell depletion with rituximab in the treatment of rheumatoid arthritis has stimulated investigation of its effects in several other immune disorders, and considerable interest in the potential of drugs that can modulate B-cell function for the treatment of such diseases in general. This article discusses the role of B cells in a range of autoimmune disorders, including rheumatoid arthritis and systemic lupus erythematosus, and analyses approaches to therapeutic B-cell manipulation.

Coexistence of thyroid autoimmunity with other autoimmune diseases: friend or foe? Additional aspects on the mosaic of autoimmunity

Autoimmunity encompasses a wide spectrum of diseases from organ-specific diseases like Hashimoto thyroiditis, to systemic diseases such as systemic lupus erythematosus. These diseases are characterized by inflammation and the production of a wide range of autoantibodies directed against multiple autoantigens. Although their etiology is still poorly understood, genetic, immunological, hormonal, and environmental factors are major predisposing and triggering factors. These multiple factors, like pieces in a mosaic, may interplay in different forms, leading to the expression of various autoimmune manifestations and diseases. This phenomenon, which has been referred by us as the "mosaic of autoimmunity", illuminates the diversity of autoimmune manifestations among susceptible individuals. From this theoretical framework we conducted a wide search of the literature, on the prevalence of thyroid autoimmunity, the commonest of the autoimmune conditions, among other autoimmune diseases, and discuss the possible clinical significance of this association.

IgA and IgG tissue transglutaminase antibodies in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) and coeliac disease (CD) are diseases of an autoimmune origin that share the human leukocyte HLA-B8 and HLA-DR3 histocompatibility antigens, yet the co-association of CD with SLE is mainly based on case reports. Thus, the real prevalence of CD in SLE is unclear. The aim of this study was to determine the prevalence of antitissue transglutaminase (anti-tTG) in SLE and the relation between SLE and CD. In this case-control study, 100 patients with SLE, and 120 healthy subjects were studied. Sera from all participants were analysed for the presence of IgA and IgG anti-tTG antibodies using a human recombinant tissue transglutaminase (tTG) immuno-enzymatic assay. Anti-tTG positive patients and controls were further tested for antiendomysial (EMA) antibodies by an indirect immunofluorescence and HLA typing (DQalpha1*0501-DQbeta1*0201 allele determination). Subjects who had EMA or the mentioned allele, underwent duodenal biopsy to confirm a possible diagnosis of CD. Anti-tTG antibodies (IgA or IgG isotypes) were found in three of the 100 SLE patients (overall prevalence of 3%): one had the IgA and two the IgG isotypes. Only 1 of 120 healthy subjects (0.8%) had a low positive reaction for IgA anti-tTG. Only the IgA anti-tTG positive SLE patient was diagnosed as having CD based on a positive IgA-EMA and small bowel biopsy findings. The two IgG anti-tTG positive SLE patients and the IgA anti-tTG positive healthy subject were classified as false positives (EMA negative and HLA DQalpha1*0501-DQbeta1*0201 allele negative). In conclusion, anti-tTG antibodies were found at a low rate in SLE patients and mostly did not indicate the presence of CD. Thus, serological screening for CD is not recommended in SLE, unless a clinical suspicion of CD is present.