B cell depletion and inhibition in systemic lupus erythematosus

Therapeutic progress in the targeting of B cells in lupus nephritis: pathogenesis to clinical research

Lupus nephritis (LN) is a common complication in patients with systemic lupus erythematosus (SLE), where the key mechanism is the deposition of immune complexes in the kidneys, leading to renal damage. B lymphocytes play a crucial role in the pathogenesis of lupus nephritis through several pathways. These include the production of autoantibodies, which contribute to the deposition of immune complexes in the kidneys, activation of the complement system, and promotion of local inflammatory responses. Additionally, B cells act as antigen-presenting cells, facilitating T cell activation, and secrete proinflammatory cytokines that further exacerbate inflammation. Moreover, an imbalance in B cell subpopulations can worsen autoimmune damage, highlighting the complex role of B cells in the progression of LN. Targeting B cells has emerged as a promising therapeutic strategy, particularly for patients with relapsed or refractory LN. Recent advances in B cell-targeted therapies have shown significant clinical potential, offering new hope for better disease management. This review highlights the latest progress in B cell-targeted approaches for LN treatment and explores their potential to revolutionize care for this challenging condition.

Urine-derived stem cells from patients alleviate lupus nephritis via regulating macrophage polarization in a CXCL14-dependent manner

AIM

Mesenchymal stem cells (MSC) exhibit hopeful therapeutic potential for the treatment of lupus nephritis (LN). Nevertheless, most MSC are harvested invasively and only transplantation of allogeneic MSC takes effect. Urine-derived stem cells (USC) can be obtained by noninvasive and safe access. Whether USC can be used for autologous stem cell transplantation to treat LN remains unknown.

MATERIALS AND METHODS

USC were harvested from healthy individuals, systemic lupus erythematosus (SLE) patients with no LN (NLN) and LN patients. The biological characteristics and immunomodulatory ability of three USC types were compared. Therapeutic value of USC for LN in MRL/lpr mice and influence of USC on macrophages were assessed. We further explored the mechanism of USC from LN patients (LN-USC) on macrophage polarization.

KEY FINDINGS

LN-USC exhibited faster proliferation and less apoptosis, significantly upregulated regulatory T cells (Treg) and downregulated antibody secreting cells (ASC). Importantly, LN-USC showed the best effect on LN in MRL/lpr mice among the three USC types. Additionally, LN-USC markedly downregulated M1 polarization of macrophages when injected into MRL/lpr mice or co-cultured with human acute monocytic leukemia cell (THP1)-derived M0 macrophages. Moreover, the regulative effect on macrophage polarization and therapeutic efficacy on LN were reversed after knocking down C-X-C motif chemokine ligand 14 (CXCL14) of LN-USC.

SIGNIFICANCE

These results suggested that transplantation of LN-USC alleviated LN in MRL/lpr mice via inhibiting M1 polarization of macrophages in a CXCL14-dependent manner, indicating that USC serve as a prospective candidate for autologous stem cell therapy of LN.

Diverse potential of chimeric antigen receptor-engineered cell therapy: Beyond cancer

BACKGROUND

Chimeric antigen receptor (CAR)-engineered cell therapies have made significant progress in haematological cancer treatment. This success has motivated researchers to investigate its potential applications in non-cancerous diseases, with substantial strides already made in this field.

MAIN BODY

This review summarises the latest research on CAR-engineered cell therapies, with a particular focus on CAR-T cell therapy for non-cancerous diseases, including but not limited to infectious diseases, autoimmune diseases, cardiac diseases and immune-mediated disorders in transplantation. Additionally, the review discusses the current obstacles that need to be addressed for broader clinical applications.

CONCLUSION

With ongoing research and continuous improvements, CAR-engineered cell therapy holds promise as a potent tool for treating various diseases in the future.

KEY POINTS

CAR-engineered cell therapy has expanded beyond cancer to treat autoimmune diseases, infections, cardiac diseases, and transplant-related rejection. The CAR platform is diverse, with various cell types such as CAR-T, CAR-NK, and CAR-M potentially suited for different disease contexts. The safety, efficacy, and practicality of CAR cell therapy in non-cancer diseases remain challenging, requiring further technological optimization and clinical translation.

Dysregulated CDKN2A-MDM2-p53 axis in B cell of systemic lupus erythematosus

BACKGROUND

The complicated autoimmune disease known as systemic lupus erythematosus (SLE) is characterized by abnormal immunological B cell modulation that exhibits enhanced survival. The genes Tp53, MDM2, and CDKN2A (ARF) play crucial roles in cellular regulation. In this study, we aim to elucidate the status of these genes. This might be a factor in the B cells' higher survival rate in SLE.

METHODS

B cells were obtained from the peripheral blood of participants and cultured, with a subset of the cells activated using anti-IgM. The expression levels of Tp53, MDM2, and CDKN2A genes were assessed both at baseline and after activation.

RESULTS

Tp53 and CDKN2A exhibited decreased expression in both baseline and activated B cells, with further decreases observed active and inactive SLE. Conversely, MDM2 demonstrated increased expression in baseline B cells, with a more pronounced increase observed in activated B cells of active SLE. Correlation analysis indicated several significant positive and negative associations, particularly between disease activity indicators and MDM2 expression, as well as among the studied genes.

CONCLUSION

The dysregulation of the CDKN2A-MDM2-p53 axis in B cells of SLE may lead to increased B cell survival due to reduced Tp53 and CDKN2A expression and elevated MDM2 levels. In addition, MDM2 gene expression levels show a significant positive correlation with disease activity indices like anti-dsDNA titer and SLEDAI score in SLE patients.

Organ-based characterization of B cells in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic, inflammatory, and progressive autoimmune disease. The unclear pathogenesis, high heterogeneity, and prolonged course of the disease present significant challenges for effective clinical management of lupus patients. Dysregulation of the immune system and disruption of immune tolerance, particularly through the abnormal activation of B lymphocytes and the production of excessive autoantibodies, lead to widespread inflammation and tissue damage, resulting in multi-organ impairment. Currently, there is no systematic review that examines the specificity of B cell characteristics and pathogenic mechanisms across various organs. This paper reviews current research on B cells in lupus patients and summarizes the distinct characteristics of B cells in different organs. By integrating clinical manifestations of organ damage in patients with a focus on the organ-specific features of B cells, we provide a new perspective on enhancing the efficacy of lupus-targeted B cell therapy strategies.

The advent of chimeric antigen receptor T Cell therapy in recalibrating immune balance for rheumatic autoimmune disease treatment

CAR-T cell therapy, a cutting-edge cellular immunotherapy with demonstrated efficacy in treating hematologic malignancies, also exhibits significant promise for addressing autoimmune diseases. This innovative therapeutic approach holds promise for achieving long-term remission in autoimmune diseases, potentially offering significant benefits to affected patients. Current targets under investigation for the treatment of these conditions include CD19, CD20, and BCMA, among others. However, CAR-T therapy faces difficulties such as time-consuming cell manufacturing, complex and expensive process, and the possibility of severe adverse reactions complicating the treatment, etc. This article examines CAR-T therapy across various rheumatic autoimmune diseases, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjögren's syndrome (SS), systemic sclerosis (SSc), antisynthetase syndrome (ASS), and ANCA-associated vasculitis (AAV), highlighting both therapeutic advancements and ongoing challenges.

The emerging role of BLyS/APRIL in autoimmune diseases: Biological characteristics, functions, and therapeutic potential

Autoimmune diseases (AIDs) are common diseases in the world. Some cases are difficult to cure and can only delay the progression of the diseases. The B lymphocyte stimulator (BLyS)/a proliferation-inducing ligand (APRIL) plays an important role in B cell homeostasis, regulation of both innate and adaptive immune responses. After binding to their receptors, BLyS/APRIL primarily affects the survival and development of marginal, transitional, and mature B cells. Of note, elevated BLyS/APRIL is seen in many AIDs, such as systemic lupus erythematosus, rheumatoid arthritis, immunoglobulin A nephropathy, etc. Moreover, there is evidence that blocking these two cytokines can control the number of serum autoantibodies, promote the depletion of B lymphocytes, inhibit the activation of T cells and dendritic lymphocytes, and reduce inflammatory stress. Currently, some clinical studies are underway targeting BLyS/APRIL inhibitors for the treatment of AIDs. However, due to the scattered knowledge on the relationship between BLyS/APRIL and AIDs, it is necessary to sort out the existing data. Therefore, in this review, we describe the basic biological characteristics and functions of BLyS/APRIL in AIDs, summarize the potential clinical applications of related inhibitors, especially monoclonal antibodies and recombinant fusion proteins targeting BLyS/APRIL in AIDs, and also outline promising research directions.

Single-dose telitacicept therapy for refractory idiopathic membranous nephropathy: A case series

Key Clinical Message

We report three cases of IMN from our center, where patients received a single dose of telitacicept after showing no response to conventional treatments. Although one case did not respond, the other two cases achieved complete or partial remission of proteinuria. These cases illustrates the telitacicept may offer new hope for the treatment of IMN.

Abstract

Despite the variety of treatment options available, effective therapies for refractory membranous nephropathy remain lacking. Recently, some reports have suggested that telitacicept is a new therapeutic option. However, only a few published studies have documented the use of telitacicept for treating idiopathic membranous nephropathy (IMN). We present three cases of IMN from our center, where patients received a single dose of telitacicept after showing no response to conventional treatments, including glucocorticoids, tacrolimus, mycophenolate mofetil, cyclophosphamide, cyclosporine, and rituximab. Although one case did not respond, the other two cases achieved complete or partial remission of proteinuria. Thus, telitacicept may offer new hope for the treatment of refractory membranous nephropathy.

Clinical Practice Mexican Guidelines for the Treatment of Systemic Lupus Erythematosus: 2024 Update

Herein we present the update for the Mexican Guidelines for the Treatment of Systemic Lupus Erythematosus. It involves the participation of several experts along the country, following the GRADE system. We included aspects regarding vaccines, pregnancy and cardiovascular risk which were not presented in the previous guidelines in 2017.

Successful management of belimumab after obinutuzumab in a patient with systemic lupus erythematosus: a case report with an 18-month follow-up

Introduction

Systemic lupus erythematosus (SLE) is a complex autoimmune disease, and despite the availability of multiple treatments, striking a balance between long-term efficacy and side effects remains a major clinical challenge. B-cell-directed therapy has attracted much attention because of its unique mechanism of action. Belimumab and obinutuzumab, as representative drugs for B-cell-directed therapy, have shown their respective advantages for SLE treatment. However, data on combination therapy with obinutuzumab and belimumab are currently unavailable.

Case presentation

We present the severe case report of a patient who was diagnosed with lupus nephritis (LN) with gastrointestinal involvement and developed acute renal failure. The patient responded to the first dose of obinutuzumab but failed to achieve a complete response to LN. The repeated use of obinutuzumab was limited by persistently low IgG levels and frequent infections. This is a real-world challenge that must be addressed. Therefore, the patient was subsequently treated with a novel sequential regimen of obinutuzumab followed by belimumab. After 18 months of follow-up, the patient achieved a complete clinical response with a favourable safety profile, along with the conversion of all autoantibodies from positive to negative and sustained negativity. To date, the patient has achieved a dual clinical and serological response.

Conclusion

There is a reason to believe that this novel combination regimen could be developed as a therapeutic strategy, with the expectation of balancing efficacy and safety.

Telitacicept: A novel horizon in targeting autoimmunity and rheumatic diseases

BLyS and APRIL have the capability to bind to B cells within the body, allowing these cells to evade elimination when they should naturally be removed. While BLyS primarily plays a role in B cell development and maturation, APRIL is linked to B cell activation and the secretion of antibodies. Thus, in theory, inhibiting BLyS or APRIL could diminish the population of aberrant B cells that contribute to SLE and reduce disease activity in patients. Telitacicept functions by binding to and neutralizing the activities of both BLyS and APRIL, thus hindering the maturation and survival of plasma cells and fully developed B cells. The design of telitacicept is distinctive; it is not a monoclonal antibody but a TACI-Fc fusion protein generated through recombinant DNA technology. This fusion involves merging gene segments of the TACI protein, which can target BLyS/APRIL simultaneously, with the Fc gene segment of the human IgG protein. The TACI-Fc fusion protein exhibits the combined characteristics of both proteins. Currently utilized for autoimmune disease treatment, telitacicept is undergoing clinical investigations globally to assess its efficacy in managing various autoimmune conditions. This review consolidates information on the mechanistic actions, dosing regimens, pharmacokinetics, efficacy, and safety profile of telitacicept-a dual-targeted biological agent. It integrates findings from prior experiments and pharmacokinetic analyses in the treatment of RA and SLE, striving to offer a comprehensive overview of telitacicept's research advancements.

The successful use of rituximab in IgA nephropathy patients with podocytopathy: a case series

Background

Immunoglobulin A nephropathy (IgAN) with podocytopathy is a rare pathological type of glomerular disease. The use of rituximab (RTX) in the treatment of glomerular diseases has increased in recent decades, but the efficacy of RTX in the treatment of patients with IgAN and podocytopathy has rarely been reported.

Methods

This was a single-centre retrospective study of IgAN patients with podocytopathy who were treated with RTX as second-line therapy was conducted at our centre from 2019 to 2022. The aim of this study was to investigate the efficacy and safety of RTX in IgAN patients with podocytopathy.

Results

Seven out of eight patients met the criteria for complete remission following RTX therapy. Only one patient experienced adverse events (infectious diarrhoea and pulmonary infection) and experienced relapse 6 months after RTX therapy. The maximum relapse-free time after RTX therapy was 20 months, while the maximum relapse-free time before RTX therapy was only 6 months. The number of relapses before RTX therapy (per year) was one to four; moreover, seven patients did not relapse and maintained remission at the last follow-up despite steroid withdrawal after RTX therapy.

Conclusion

Overall, RTX effectively reduced proteinuria, increased the maximum relapse-free time, reduced the number of relapses per year and helped patients stop steroid use as soon as possible. RTX also helped most patients achieve clinical remission. RTX appears to be an effective and safe alternative for treating IgAN patients with podocytopathy with steroid dependence or frequent relapse.

New and emerging therapies for systemic lupus erythematosus

Systemic Lupus Erythematosus (SLE) and lupus nephritis treatment is still based on non-specific immune suppression despite the first biological therapy for the disease having been approved more than a decade ago. Intense basic and translational research has uncovered a multitude of pathways that are actively being evaluated as treatment targets in SLE and lupus nephritis, with two new medications receiving FDA approval in the last 3 years. Herein we provide an overview of targeted therapies for SLE including medications targeting the B lymphocyte compartment, intracellular signaling, co-stimulation, and finally the interferons and other cytokines.

Targeted Treatment of Diseases of Immune Dysregulation

Increasing molecular knowledge of autoinflammatory and autoimmune disorders has enabled more targeted treatment of these conditions. Treatment of inflammasomopathies is often aimed at interleukin-1 (IL-1) blockade, with potential use of other inhibitors targeting cytokines such as IL-18 and IL-6. Interferonopathies and some disorders with overlap features of autoimmunity and autoinflammation may improve with Janus kinase inhibition. Autoimmune conditions may also respond to inhibition of different cytokines, as well as to inhibition of T and B lymphocytes. Effective treatment is increasingly possible through targeted/precision medicine approaches.

Case report: Successful treatment of refractory membranous nephropathy with telitacicept

Despite various treatment methods, the remission rate of membranous nephropathy remains limited. Refractory membranous nephropathy especially lacks effective treatment plans. Telitacicept achieves comprehensive inhibition of CD20-positive B cells, plasma cells, and T cells, thereby bringing new hope to the treatment of membranous nephropathy and refractory membranous nephropathy. Here, we report a case of a 46-year-old man with membranous nephropathy. Although the combined treatment with glucocorticoid, tacrolimus, mycophenolate mofetil, cyclophosphamide, and rituximab was not successful, the patient achieved complete remission of urinary protein after glucocorticoid combined with telitacicept. This is the first report on the application of telitacicept in the treatment of membranous nephropathy, especially refractory membranous nephropathy. The application of telitacicept in the treatment of membranous nephropathy deserves further attention.

Pathogenic cellular and molecular mediators in lupus nephritis

Kidney involvement in patients with systemic lupus erythematosus - lupus nephritis (LN) - is one of the most important and common clinical manifestations of this disease and occurs in 40-60% of patients. Current treatment regimens achieve a complete kidney response in only a minority of affected individuals, and 10-15% of patients with LN develop kidney failure, with its attendant morbidity and considerable prognostic implications. Moreover, the medications most often used to treat LN - corticosteroids in combination with immunosuppressive or cytotoxic drugs - are associated with substantial side effects. Advances in proteomics, flow cytometry and RNA sequencing have led to important new insights into immune cells, molecules and mechanistic pathways that are instrumental in the pathogenesis of LN. These insights, together with a renewed focus on the study of human LN kidney tissue, suggest new therapeutic targets that are already being tested in lupus animal models and early-phase clinical trials and, as such, are hoped to eventually lead to meaningful improvements in the care of patients with systemic lupus erythematosus-associated kidney disease.