New therapeutics in systemic lupus erythematosus

Rituximab Followed by Belimumab Controls Severe Lupus Nephritis and Bullous Pemphigoid in Systemic Lupus Erythematosus Refractory to Several Combination Therapies

Systemic lupus erythematosus (SLE) and bullous pemphigoid (BP) are chronic autoimmune diseases in which B cells play an important pathogenic role in the different stages of the disease. B cell-targeted therapies have been suggested as a new rational approach for treating SLE. Rituximab (RTX), an anti-CD20 chimeric monoclonal antibody, failed to achieve primary endpoints in two clinical trials (EXPLORER and LUNAR) despite multiple observational and retrospective studies showing its beneficial effect on SLE. Moreover, RTX is recommended in cases of BP that is unresponsive to conventional treatments. Belimumab (BLM), a human immunoglobulin G1 λ monoclonal antibody that inhibits soluble B-lymphocyte stimulator (BlyS)/B-cell activating factor (BAFF), is the only biological treatment approved for standard therapy of refractory autoantibody-positive active SLE. Animal models and a few case reports have supported the efficacy of the combined use of RTX followed by BLM as maintenance therapy in severe lupus nephritis (LN), suggesting that their combined use may be more effective than their single use, without compromising safety. In this study, we describe the clinical case of a SLE patient with predominant renal involvement in overlap with BP, refractory to conventional therapy including RTX alone, achieving significant steroid sparing and clinical remission under sequential treatment of RTX-BLM. Moreover, we describe the first case of BP successfully treated with BLM. This case report may encourage further clinical research studies in B lymphocyte targeted combination therapy in patients affected by SLE with major organ involvement or with refractory disease, suggesting that RTX and BLM sequential therapy may be a valid option for the treatment of SLE manifestations, including conventional therapy and RTX-resistant LN.

IL233, an IL-2-IL-33 hybrid cytokine induces prolonged remission of mouse lupus nephritis by targeting Treg cells as a single therapeutic agent

Lupus glomerulonephritis (GN) is an autoimmune disease characterized by immune complex-deposition, complement activation and glomerular inflammation. In lupus-prone NZM2328 mice, the occurrence of lupus GN was accompanied by a decrease in Treg cells and an increase in proinflammatory cytokine-producing T cells. Because IL-33 in addition to IL-2 has been shown to be important for Treg cell proliferation and ST2 (IL-33 receptor) positive Treg cells are more potent in suppressor activity, a hybrid cytokine with active domains of IL-2 and IL-33 was generated to target the ST2⁺ Treg cells as a therapeutic agent to treat lupus GN. Three mouse models were used: spontaneous and Ad-IFNα- accelerated lupus GN in NZM2328 and the lymphoproliferative autoimmune GN in MRL/lpr mice. Daily injections of IL233 for 5 days prevented Ad-IFNα-induced lupus GN and induced remission of spontaneous lupus GN. The remission was permanent in that no relapses were detected. The remission was accompanied by persistent elevation of Treg cells in the renal lymph nodes. IL233 is more potent than IL-2 and IL-33 either singly or in combination in the treatment of lupus GN. The results of this study support the thesis that IL233 should be considered as a novel agent for treating lupus GN.

Metabolic Factors that Contribute to Lupus Pathogenesis

Systemic lupus erythematosus (SLE) is an autoimmune disease in which organ damage is mediated by pathogenic autoantibodies directed against nucleic acids and protein complexes. Studies in SLE patients and in mouse models of lupus have implicated virtually every cell type in the immune system in the induction or amplification of the autoimmune response as well as the promotion of an inflammatory environment that aggravates tissue injury. Here, we review the contribution of CD4+ T cells, B cells, and myeloid cells to lupus pathogenesis and then discuss alterations in the metabolism of these cells that may contribute to disease, given the recent advances in the field of immunometabolism.

Uveitis in childhood-onset systemic lupus erythematosus patients: a multicenter survey

The aim of this study is to assess uveitis prevalence in a large cohort of childhood-onset systemic lupus erythematosus (cSLE) patients. A retrospective multicenter cohort study including 852 cSLE patients was performed in ten pediatric rheumatology centers (Brazilian cSLE group). An investigator meeting was held and all participants received database training. Uveitis was diagnosed through clinical assessment by the uveitis expert ophthalmologist of each center. Patients with and without uveitis were assessed for lupus clinical/laboratory features and treatments. Uveitis was observed in 7/852 cSLE patients (0.8%). Two of them had ocular complications: cataract and irreversible blindness in one patient and retinal ischemia with subsequent neovascularization and unilateral blindness in another. Uveitis was identified within the first 6 months of cSLE diagnosis in 6/7 patients (86%). Comparison of a subgroup of cSLE patients with (n = 7) and without uveitis (n = 73) and similar length of disease duration showed that patients with uveitis had increased SLEDAI-2K score (19 vs. 6; p < 0.01). In addition, fever (71 vs. 12%; p < 0.01), lymphadenopathy (29 vs. 1.4%; p = 0.02), arthritis (43 vs. 7%; p = 0.02), and use of intravenous methylprednisolone (71 vs. 22%; p = 0.01) were higher in cSLE patients with uveitis, as compared to those without this manifestation, respectively. Presence of fever was significantly associated with uveitis, independently of SLEDAI scores or use of intravenous methylprednisolone pulses, as shown by adjusted regression analysis (adjusted prevalence ratio 35.7, 95% CI 2.4-519.6; p < 0.01). Uveitis was a rare and initial manifestation of active cSLE patients. Early recognition is essential due to the possibility of irreversible blindness.

Specific HDAC6 inhibition by ACY-738 reduces SLE pathogenesis in NZB/W mice

We sought to determine if a selective HDAC6 inhibitor (ACY-738) decreases disease in NZB/W mice. From 22 to 38weeks-of-age, mice were injected intraperitoneally with 5 or 20mg/kg of ACY-738, or vehicle control. Body weight and proteinuria were measured every 2weeks, while sera anti-dsDNA, Ig isotypes, and cytokine levels were measured every 4weeks. Kidney disease was determined by evaluation of sera, urine, immune complex deposition, and renal pathology. Flow cytometric analysis assessed thymic, splenic, bone marrow, and peripheral lymphocyte differentiation patterns. Our results showed HDAC6 inhibition decreased SLE disease by inhibiting immune complex-mediated glomerulonephritis, sera anti-dsDNA levels, and inflammatory cytokine production and increasing splenic Treg cells. Inhibition of HDAC6 increased the percentage of cells in the early-stage developmental fractions of both pro- and pre-B cells. These results suggest that specific HDAC6 inhibition may be able to decrease SLE disease by altering aberrant T and B cell differentiation.

The pathogenesis, diagnosis and treatment of lupus nephritis

PURPOSE OF REVIEW

Renal involvement is a major cause of morbidity and mortality in systemic lupus erythematosus. In this review, we provide an update on recent discoveries in the pathogenesis, diagnosis, and treatment of lupus nephritis.

RECENT FINDINGS

Localized long-lived plasma cells have been identified as playing an important role in lupus nephritis. In addition, the roles of aberrant expression of microRNAs and proinflammatory cytokines have been explored. Early diagnosis is important for effective treatment and multiple biomarkers have been identified; however, none has been yet validated for clinical use. Biomarker panels may turn out to be more accurate than each individual component. Biologic agents for the treatment of lupus nephritis are being studied, including belimumab which was recently approved for nonrenal systemic lupus erythematosus. Rituximab has not proven itself in large, placebo-controlled trials, although it is still being used in refractory cases of lupus nephritis.

SUMMARY

Lupus nephritis is a potentially devastating complication of systemic lupus erythematosus. Immune cells, cytokines, and epigenetic factors have all been recently implicated in lupus nephritis pathogenesis. These recent discoveries may enable a paradigm shift in the treatment of this complex disease, allowing the tailoring of treatment to target specific pathogenic mediators at specific points in time in the progression of disease.

VIDEO ABSTRACT

Resetting the autoreactive immune system with a therapeutic peptide in lupus

Over the last decade there has been a rapid expansion in the use of peptides as drugs. Nowadays, they are being used therapeutically in such diverse areas as endocrinology, neurology, haematology and some types of allergies. In the field of autoimmunity, a few candidates have emerged. Thus, in the pipeline of novel strategies designed to treat patients with systemic lupus erythematosus, the 21-mer peptide P140/Lupuzor raises hopes for the generation of an efficient, specific and safe treatment. This phosphopeptide has successfully completed a phase IIb clinical trial and will enter into a multi-centre, double-blind, placebo-controlled phase III clinical trial. The phase IIb trial showed that after three months of therapy (three subcutaneous injections of 200 µg peptide/patient in addition to standard of care), Lupuzor improved Systemic Lupus Erythematosus Disease Activity Index score of lupus patients under active treatment by 67.6% versus 41.5% in the placebo group ( p < 0.025). After three additional months of follow-up, the improvement rate was 84.2% versus 45.8% ( p < 0.025). The side-effect profile was unproblematic and the drug was well tolerated as evidenced by a very low drop-out rate. P140 does not behave as an immunosuppressant, it acts primarily as a fine immunomodulator of autoreactive CD4+ T cells. Its underlying mechanism of action involves autophagy, a cellular process that implicates lysosomal-dependent recycling of intracellular components and controls the pool of major histocompatibility complex class II-displayed peptides that is presented to CD4+ T cells.

Epigenetics in the treatment of systemic lupus erythematosus: potential clinical application

The current treatments of systemic lupus erythematosus (SLE) have been based on the use of immunosuppressive drugs which are linked to serious side effects. The more effective therapeutic approaches with minimal or no side effects for SLE patients are hard to develop, mainly due to the complexity of the disease. The discovery of pharmacoepigenetics provides a new way to solve this problem. Epigenetic modifications can influence drug efficacy by altering gene expression via changing chromatin structure. Although still in early development, epigenetic studies in SLE are expected to reveal novel therapeutic targets and disease biomarkers in autoimmunity. For example, miRNAs, which have been identified to govern many genes including drug targets, are altered in disease development and after drug administration. This review aims to present an overview of current epigenetic mechanisms involved in the pathogenesis of SLE, and discuss their potential roles in clinical and pharmacological applications.

Upregulated PD-1 Expression Is Associated with the Development of Systemic Lupus Erythematosus, but Not the PD-1.1 Allele of the PDCD1 Gene

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with complicated genetic inheritance. Programmed death 1 (PD-1), a negative T cell regulator to maintain peripheral tolerance, induces negative signals to T cells during interaction with its ligands and is therefore a candidate gene in the development of SLE. In order to examine whether expression levels of PD-1 contribute to the pathogenesis of SLE, 30 patients with SLE and 30 controls were recruited and their PD-1 expression levels in peripheral blood mononuclear cells (PBMCs) were measured via flow cytometry and quantitative real-time-reverse transcription polymerase chain reaction (RT-PCR). Also, whether PD-1 expression levels are associated with the variant of the SNP rs36084323 and the SLE Disease Activity Index (SLEDAI) was studied in this work. The PD-1 expression levels of SLE patients were significantly increased compared with those of the healthy controls. The upregulated PD-1 expression levels in SLE patients were greatly associated with SLEDAI scores. No significant difference was found between PD-1 expression levels and SNP rs36084323. The results suggest that increased expression of PD-1 may correlate with the pathogenesis of SLE, upregulated PD-1 expression may be a biomarker for SLE diagnosis, and PD-1 inhibitor may be useful to SLE treatment.

Aseptic necrosis at multiple localisations in a lupus patient with lymphoma

Avascular or aseptic necrosis is a well-defined entity leading to the degradation of cellular elements of the bone. The pathogenesis of osteonecrosis (ON) is still unknown. There are two main types of ON: traumatic or non-traumatic. Several clinical entities could associate with ON, systemic diseases, environmental factors, pregnancy, systemic autoimmune or rheumatic diseases, thrombophilia, corticosteroid therapy, cytotoxic dugs, infections, metabolic and hematologic diseases, etc. Corticosteroids (CS) are still the most frequently used therapeutic options in the early phase and during flares of these diseases. Inflammatory cytokines and antibodies have been described to participate in the pathogenesis of ON. The infiltrative disorders of the bone marrow could also contribute to the development of ON. Hereby, we describe a female patient with NHL followed by SLE in whom ON has developed at least in two localisations. Lupus flare, long-term CS therapy, lymphoma relapse or the presence of antiphospholipid antibodies were excluded. Although the bi-localised ON could be contributed to immunologic factors or trauma, the exact aetiology in this case could not be elucidated.

Genetics of proteasome diseases

The proteasome is a large, multiple subunit complex that is capable of degrading most intracellular proteins. Polymorphisms in proteasome subunits are associated with cardiovascular diseases, diabetes, neurological diseases, and cancer. One polymorphism in the proteasome gene PSMA6 (-8C/G) is associated with three different diseases: type 2 diabetes, myocardial infarction, and coronary artery disease. One type of proteasome, the immunoproteasome, which contains inducible catalytic subunits, is adapted to generate peptides for antigen presentation. It has recently been shown that mutations and polymorphisms in the immunoproteasome catalytic subunit PSMB8 are associated with several inflammatory and autoinflammatory diseases including Nakajo-Nishimura syndrome, CANDLE syndrome, and intestinal M. tuberculosis infection. This comprehensive review describes the disease-related polymorphisms in proteasome genes associated with human diseases and the physiological modulation of proteasome function by these polymorphisms. Given the large number of subunits and the central importance of the proteasome in human physiology as well as the fast pace of detection of proteasome polymorphisms associated with human diseases, it is likely that other polymorphisms in proteasome genes associated with diseases will be detected in the near future. While disease-associated polymorphisms are now readily discovered, the challenge will be to use this genetic information for clinical benefit.