B cell activating factor (BAFF): Structure, functions, autoimmunity and clinical implications in Systemic Lupus Erythematosus (SLE)

Challenges and advances in the management of inflammation in atherosclerosis

INTRODUCTION

Atherosclerosis, traditionally considered a lipid-related disease, is now understood as a chronic inflammatory condition with significant global health implications.

OBJECTIVES

This review aims to delve into the complex interactions among immune cells, cytokines, and the inflammatory cascade in atherosclerosis, shedding light on how these elements influence both the initiation and progression of the disease.

METHODS

This review draws on recent clinical research to elucidate the roles of key immune cells, macrophages, T cells, endothelial cells, and clonal hematopoiesis in atherosclerosis development. It focuses on how these cells and process contribute to disease initiation and progression, particularly through inflammation-driven processes that lead to plaque formation and stabilization. Macrophages ingest oxidized low-density lipoprotein (oxLDL), which partially converts to high-density lipoprotein (HDL) or accumulates as lipid droplets, forming foam cells crucial for plaque stability. Additionally, macrophages exhibit diverse phenotypes within plaques, with pro-inflammatory types predominating and others specializing in debris clearance at rupture sites. The involvement of CD4+ T and CD8+ T cells in these processes promotes inflammatory macrophage states, suppresses vascular smooth muscle cell proliferation, and enhances plaque instability.

RESULTS

The nuanced roles of macrophages, T cells, and the related immune cells within the atherosclerotic microenvironment are explored, revealing insights into the cellular and molecular pathways that fuel inflammation. This review also addresses recent advancements in imaging and biomarker technology that enhance our understanding of disease progression. Moreover, it points out the limitations of current treatment and highlights the potential of emerging anti-inflammatory strategies, including clinical trials for agents such as p38MAPK, tumor necrosis factor α (TNF-α), and IL-1β, their preliminary outcomes, and the promising effects of canakinumab, colchicine, and IL-6R antagonists.

CONCLUSION

This review explores cutting-edge anti-inflammatory interventions, their potential efficacy in preventing and alleviating atherosclerosis, and the role of nanotechnology in delivering drugs more effectively and safely.

Proteomic analysis of B cells in peripheral lymphatic system reveals the dynamics during the systemic lupus erythematosus progression

In this study, we conducted a comprehensive proteomic analysis of B cells from the spleen, mesenteric lymph nodes (mLN), and peripheral blood mononuclear cells (PBMC) in a time-course model of systemic lupus erythematosus (SLE) using female MRL/lpr mice. By combining fluorescence-activated cell sorting (FACS) and 4D-Data-Independent Acquisition (4D-DIA) mass spectrometry, we quantified nearly 8000 proteins, identifying significant temporal and tissue-specific proteomic changes during SLE progression. PBMC-derived B cells exhibited early proteomic alterations by Week 9, while spleen-derived B cells showed similar changes by Week 12. We identified key regulatory proteins, including BAFF, BAFFR, and NFKB2, involved in B cell survival and activation, as well as novel markers such as CD11c and CD117, which have previously been associated with other immune cells. The study highlights the dynamic reprogramming of B cell proteomes across different tissues, with distinct contributions to SLE pathogenesis, providing valuable insights into the molecular mechanisms underlying B cell dysregulation in lupus. These findings offer potential therapeutic targets and biomarkers for SLE.

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.

Development of Diffuse Large B Cell Lymphoma in a Patient with Systemic Lupus Erythematosus within Two Years after the Initiation of Anifrolumab and Mycophenolate Mofetil Treatment

Anifrolumab is a newly developed biological agent for patients with moderate-to-severe systemic lupus erythematosus (SLE). Anifrolumab neutralizes the signaling pathways mediated by type I interferons (IFNs), which are involved in viral clearance and anticancer immunity. Although susceptibility to viral infections has been reported in patients treated with anifrolumab, whether anifrolumab treatment increases the cancer risk in patients with SLE is unknown. We herin report a case of SLE that manifested as aggressive diffuse large B-cell lymphoma (DLBCL) after treatment with anifrolumab. The neutralization of type I IFNs by anifrolumab may promote the development of DLBCL owing to defective anticancer immunity.

Early decrease of T-bet+ B cells during subcutaneous belimumab predicts response to therapy in systemic lupus erythematosus patients

Systemic lupus erythematosus (SLE) is characterized by B cell dysregulation and expansion of atypical B cells that may correlate with disease manifestations and activity. This study investigated the impact of subcutaneous (sc) Belimumab (BLM) on the peripheral B cell compartment and on the functional properties of CD21low, T-bet+ and CD11c+ atypical B cells, in 21 active SLE patients over a 12-month period. At baseline, active SLE patients displayed reduced unswitched IgM memory B cells and expansion of atypical B cells, compared to healthy donors and to SLE patients in remission. sc BLM therapy promptly restored B cell homeostasis with a reduction of T-bet+ B cells, observed early in patients responsive to therapy. These findings highlight the pathogenic role of T-bet+ B cells in SLE disease and suggest their potential utility as biomarker of clinical response.

Advances in maintenance therapies for neuromyelitis optica spectrum disorders: A new era of targeted drugs

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a rare inflammatory demyelinating disease of the central nervous system, mainly affecting the optic nerve and spinal cord, with a high rate of recurrence and disability. The spectrum of possibilities for NMOSD maintenance therapies has increased recently due to the development of novel medications based on a deeper understanding of its pathogenesis.

METHODS

Clinical and preclinical advances in NMOSD maintenance therapies were searched in PubMed up until July 20, 2024.

RESULTS

We reviewed the treatment options including approved monoclonal antibodies, clinical trial drugs, and preclinical targets. Both randomized clinical trials and real-word studies have evaluated the safety and efficacy of monoclonal antibodies against complement, IL-6 receptor and B cells. Drugs in the early stage of clinical trials are mainly focused on small molecule targeted drugs and cell-based therapies. Additionally, preclinical studies aimed to explore new targets, such as aquaporin blocking antibodies, based on experiences in cell cultures and animal models.

CONCLUSIONS

From biologics to small molecules and cells, researchers have endeavored to provide better medical care for NMOSD patients. With the emergence of more and more targeted drugs, it is anticipated that the treatment of NMOSD will enter a new era.

Kidney transplantation in Lupus Nephritis: a comprehensive review of challenges and strategies

PURPOSE OF REVIEW: Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE), significantly impacting patient outcomes. Despite advances in immunosuppressive therapies, many patients progress to end-stage renal disease (ESRD), and kidney transplantation becomes essential for improving survival. However, the unique characteristics of autoimmune diseases make the timing of kidney transplantation and post-transplant management challenging. This review evaluates authoritative guidelines and recent studies to identify optimal timing for kidney transplantation and effective pre- and post-transplant management measures for patients with LN. RECENT FINDINGS: Advancements in immunosuppressive therapies, including calcineurin inhibitors, Voclosporin, and biologic agents such as belimumab, have significantly improved LN management. Emerging biomarkers, such as urinary MCP-1 and BAFF, offer promising tools for monitoring LN activity and predicting recurrence risk post-transplantation. Current guidelines emphasize the importance of achieving disease quiescence before transplantation, while new evidence supports the benefits of preemptive transplantation and personalized immunosuppressive regimens in improving patient and graft survival. This review highlights the latest evidence and strategies for optimizing kidney transplantation outcomes in LN patients, focusing on timing, immunosuppression, and disease monitoring.

Telitacicept for systemic lupus erythematosus with post‑surgical papillary thyroid carcinoma: A case report

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a complex etiology primarily linked to abnormalities in B lymphocytes within the human body, resulting in the production of numerous pathogenic autoantibodies. Telitacicept is a relatively novel humanized, recombinant transmembrane activator, calcium modulator and cyclophilin ligand interactor fused with the Fc portion (TACI-Fc). It works by competitively inhibiting the TACI site, neutralizing the activity of B-cell lymphocyte stimulator and A proliferation-inducing ligand. This, in turn, inhibits the development and survival of plasma cells and mature B cells. A 28-year-old female was admitted to the Department of Rheumatology and Immunology (People's Hospital of Longhua; Shenzhen, China) in June 2021 due to systemic edema for more than a month and hair loss lasting for a week. After comprehensive examination, the patient was diagnosed with SLE with hematological system involvement, serositis, lupus nephritis and secondary antiphospholipid syndrome. After receiving medications including glucocorticoids, mycophenolate mofetil and cyclosporine, the patient's white blood cells, platelets, hemoglobin, urinary protein and multiple serositis returned to normal. However, the levels of complement 3 (C3) and C4 did not significantly improve. Subsequently, the patient underwent thyroid ultrasound examination, which suggested thyroid nodules. After thyroid puncture biopsy, the patient was diagnosed with papillary thyroid carcinoma (PTC). After surgical resection, the patient was confirmed to have PTC by pathological biopsy, with no lymph node metastasis. At two months after surgery, the patient was treated with telitacicept, and the complement levels not only returned to normal but also remained stable for a long time. The present case was the first to report the use of telitacicept for the successful treatment of a patient with SLE with post-surgical PTC, providing a potential therapeutic option for SLE with a prior history of carcinoma. The role of telitacept in this field requires further research and attention.

Memory B cells and their transcriptomic profiles associated with belimumab resistance in systemic lupus erythematosus in the maintenance phase

The factors contributing to the treatment efficacy of belimumab in patients with systemic lupus erythematosus (SLE) in the maintenance phase are unknown. Here, we collected blood samples from patients with SLE (n=44) treated with belimumab before and three and six months after treatment. RNA-Seq of whole blood was performed, and gene expression was quantified. Immune cell type enrichment analysis estimated immune cell subtype proportions and gene expression in each subtype. The Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) < 4 at six months was set as the primary efficacy criterion. Non-responders exhibited upregulated B cell proliferation signals before treatment, associated with an increased number of memory B cells. A higher proportion of memory B cells before treatment predicted poor response (p=5.1×10-4). This was also associated with changes in disease activity and glucocorticoid dose at six months compared with baseline. Belimumab did not affect memory B cell proportion during the treatment time course, in contrast to naïve B cells. Higher memory B cell proportion was associated with higher type-I interferon (IFN) scores and lower white blood cell and complement C4 levels. Transcriptomic analysis of memory B cells in non-responders revealed significant upregulation of immunoglobulin genes (Ig). Memory B cells and high Ig expression in them were identified as a treatment-resistant factor of belimumab in SLE patients. Lower C4 and white blood cell counts may serve as clinical markers of higher memory B cells.

CAR-T cell targeting three receptors on autoreactive B cells for systemic lupus erythematosus therapy

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by dysregulated B cell activation, autoantibody production, and nephritis. B cell activating factor (BAFF) overexpression enhances autoreactive B-cell survival, driving autoimmunity. BAFF specific belimumab and CD20 specific rituximab antibodies are used for SLE therapy but are not curative, highlighting the need for alternative B cell depletion therapies. Here, we use BAFF ligand based chimeric antigen receptor T (CAR-T) cells targeting BAFFr, BCMA and TACI expressed on mature B cells and plasma cells. BAFF CAR-T cells efficiently killed B cells after co-culture with peripheral blood mononuclear cells (PBMCs) from SLE patients and in a patient derived SLE xenograft humanized mouse model developed by injecting patient PBMCs into immunocompromised mice. We also generated murine CD8+ T cells expressing human BAFF CAR to test their therapeutic efficacy in spontaneous (MRL/lpr) and pristane induced mouse models of SLE. In both models, BAFF CAR-T cells mediated persistent elimination of mature B cells, resulting in a decrease in the production of autoantibodies (IgM, IgG, Anti-ANA, and Anti-dsDNA IgG) and proteinuria along with prolonged survival. Adoptive transfer of B cells from control MRL/lpr lupus mice to previously BAFF CAR-T treated MRL/lpr lupus mice showed continued depletion of B cells and prolonged survival. Potential advantages of BAFF CAR-T therapy include avoiding B cell aplasia as BAFF receptors are not expressed by early B cells and preventing the escape of long-lived plasma cells post BAFF CAR-T therapy as they express receptors of BAFF. These data demonstrate the potential for a cellular immunotherapy based approach to induce remission of SLE pathogenesis using BAFF-CAR-T therapy.

Improvement of high-density lipoprotein atheroprotective properties in patients with systemic lupus erythematosus after belimumab treatment

OBJECTIVE

Chronic inflammatory diseases, like Systemic Lupus Erythematosus (SLE), carry an increased risk for atherosclerosis and cardiovascular events, accompanied by impairment of atheroprotective properties of high-density lipoprotein (HDL). In SLE, serum B cell-activating factor (BAFF), a cytokine implicated in disease progression, has been correlated with subclinical atherosclerosis. We investigated the impact of treatment with belimumab -an anti-BAFF monoclonal antibody- on HDL atheroprotective properties and composition in SLE patients.

METHODS

Serum samples were collected from 35 SLE patients with active disease despite conventional therapy, before and after 6-month add-on treatment with belimumab, and 26 matched healthy individuals. We measured cholesterol efflux and antioxidant capacities, paraoxonase-1 (PON1) activity, serum amyloid A1 (SAA1), myeloperoxidase (MPO) and lipid peroxidation product levels of HDL. LC-MS/MS was performed to analyse the HDL lipidome.

RESULTS

Following treatment with belimumab, cholesterol efflux and antioxidant capacities of HDL were significantly increased in SLE patients and restored to levels of control subjects. HDL-associated PON1 activity was also increased, whereas lipid peroxidation products were decreased following treatment. HDL cholesterol efflux and antioxidant capacities correlated negatively with the disease activity. Changes were noted in the HDL lipidome of SLE patients following belimumab treatment, as well as between SLE patients and healthy individuals, and specific changes in lipid species correlated with functional parameters of HDL.

CONCLUSIONS

HDL of SLE patients with active disease displays impaired atheroprotective properties accompanied by distinct lipidomic signatures compared with controls. Belimumab treatment may improve the HDL atheroprotective properties and modify the HDL lipidomic signature in SLE patients, thus potentially mitigating atherosclerosis development.

Predictors of renal flares in systemic lupus erythematosus: a post-hoc analysis of four phase III clinical trials of belimumab

OBJECTIVE

The objective of this study was to identify predictors of renal flares in patients with SLE treated for active extra-renal disease.

METHODS

Data from four clinical trials of belimumab in SLE (BLISS-52, NCT00424476; BLISS-76, NCT00410384; BLISS-NEA, NCT01345253; BLISS-SC, NCT01484496) were used. Patients were assigned to belimumab or placebo on top of standard therapy. We investigated the performance of predictors of renal flares through weeks 52-76 using proportional hazards regression analysis.

RESULTS

Of 3225 participants, 192 developed at least one renal flare during follow-up, with the first occurring after a median time of 197 days. Current/former renal involvement [hazards ratio (HR): 15.4; 95% CI: 8.3-28.2; P < 0.001], low serum albumin levels (HR 0.9; 95% CI: 0.8-0.9; P < 0.001), proteinuria (HR: 1.6; 95% CI: 1.5-1.7; P < 0.001), and low C3 levels (HR: 2.9; 95% CI: 2.1-4.1; P < 0.001) at baseline appeared robust determinants of impending renal flares. Anti-dsDNA positivity yielded an increased hazard for renal flares (HR: 2.1; 95% CI: 1.4-3.2; P < 0.001), which attenuated after adjustments. Anti-Sm positivity was associated with renal flares in the placebo (HR: 3.7; 95% CI: 2.0-6.9; P < 0.001) but not in the belimumab subgroup, whereas anti-ribosomal P positivity was associated with renal flares in the belimumab subgroup only (HR: 2.8; 95% CI: 1.5-5.0; P = 0.001).

CONCLUSION

A history of renal involvement, high baseline proteinuria, hypoalbuminaemia, and C3 consumption were robust determinants of impending renal flares. In addition to anti-dsDNA, anti-Sm and anti-ribosomal P protein antibody positivity may have value in surveillance of renal SLE.

Risk factors associated with thrombocytopenia in systemic lupus erythematosus: A systematic review and meta-analysis

BACKGROUND

Systemic lupus erythematosus (SLE) frequently manifests with thrombocytopenia (TP), a hematologic complication that heightens the risk of severe outcomes and increases mortality. This meta-analysis aims to evaluate the potential risk factors associated with TP in SLE patients, providing insights into the demographic features, clinical features, and laboratory findings that contribute to this condition.

METHODS

A comprehensive literature search was conducted across eight databases from inception to September 1, 2024. Study quality was assessed using the Newcastle-Ottawa Scale. Meta-analysis was conducted using univariate and multivariate analyses with Revman 5.3, while heterogeneity was addressed through subgroup and sensitivity analyses. Publication bias was assessed using funnel plots and Egger tests via Stata 15.0.

RESULTS

Seventeen high-quality studies meeting the inclusion criteria were incorporated into this meta-analysis. Independent risk factors for TP in SLE included age (Demographic Features), serositis, splenomegaly, blood system involvement, and renal involvement (Clinical Features), as well as cardiac involvement, anemia, leukocytopenia, low C3/C4, ACA, and CRP (Laboratory Findings). Arthritis and rash were protective factors. Subgroup analysis addressed heterogeneity caused by unit and sample size differences. Sensitivity analysis comparing the consistency between fixed-effects model (FEM) and random-effects model (REM) confirmed the reliability of the findings, and both funnel plots and Egger tests suggested no publication bias.

CONCLUSION

This meta-analysis identified several potential independent risk factors for TP in SLE. Early screening and timely intervention for patients with these risk factors are essential to reduce the likelihood of TP, prevent severe organ damage, and improve overall prognosis.

Monoclonal antibodies - A repertoire of therapeutics

Antibodies are a class of biomolecules armed with extraordinary diversity, unmatched in the biological world by any other class of molecules. This characteristic feature equips antibodies to recognize, bind, and eliminate an infinite number of pathogens/antigens facilitated by their effector functions. The repertoire of natural binding specificities of antibodies (Abs) is greater than the calculated estimate of ∼1012 in humans, as a naive, single antigen-binding site may bind more than one antigen employing the plasticity in antigen-antibody interactions, potentiating Abs to fight infinite pathogenic insults and restrict the development of cancers. Additionally, advanced technological interventions, by allowing manipulation of the germline and acquired specificities of human/animal immunoglobulins (Ig) have contributed immensely to broaden their existing repertoire and scope of clinical applications. The available natural repertoire of Ig and Ig-like molecules in other animals, e.g., mice, horses, cows, pigs, rabbits, camels, llamas, etc., further diversified the source of unique antigen-binding specificities. The recombinant DNA technology, in association with hybridoma , transgenic, and phage display technologies, has helped create a parallel repertoire of unique antibody molecules [animal Abs, camelid heavy chain Abs (hcAbs), chimeric Abs, chimeric hcAbs, humanized Abs, humanized nanobody (Nb)-hcAbs, human Abs, etc.], monoclonal Ab (mAb) derived fragments [antigen-binding-fragment (Fab), single-chain-variable-fragment (scFv), variable-fragement (Fv), single-variable-domain of hcAbs (VHH), bispecific scFv, diabodies, triabodies, intrabodies, bispecific Fabs, tri-specific Fabs, etc.), and immunoconjugates generated by fusing/conjugating mAb fragments with enzyme, toxin, prodrug etc., molecules. The current chapter provides a detailed description of the natural and engineered antibody repertoires and discusses various strategies using which these molecules are being inducted as novel immunotherapeutics for treating a significant number of human diseases.

Differential Expression of tRNA-Derived Small RNA Markers of Antidepressant Response and Functional Forecast of Duloxetine in MDD Patients

BACKGROUND/OBJECTIVES

Duloxetine, despite being a leading treatment option for major depressive disorder (MDD), exhibits a relatively low adequate response rate when used as a monotherapy, and the fundamental molecular mechanisms remain largely elusive. tRNA-derived small RNA (tsRNA) is a particularly interesting and new class of molecules that is becoming increasingly noticeable for investigation.

METHODS

We integrated small RNA sequencing with bioinformatics approaches to dissect the expression profiles of tsRNAs and decipher their functional roles post-duloxetine treatment. Subsequently, molecular docking experiments were carried out to validate the potential functions.

RESULTS

Ten tsRNAs significantly changed in the duloxetine response group after an 8-week therapy. Correlation analyses revealed that these tsRNAs predominantly interacted with miRNAs across multiple biological pathways and processes, such as the ECM-receptor interaction and B cell activation. Molecular docking analysis corroborated the binding capabilities of duloxetine with key proteins associated with ECM1 and BAFF, respectively.

CONCLUSIONS

The identified changes in tsRNAs can precisely mirror the response of duloxetine in MDD treatment, offering novel insights into the underlying mechanisms of duloxetine action.

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.

Hyperreactive B cells instruct their elimination by T cells to curb autoinflammation and lymphomagenesis

B cell immunity carries the inherent risk of deviating into autoimmunity and malignancy, which are both strongly associated with genetic variants or alterations that increase immune signaling. Here, we investigated the interplay of autoimmunity and lymphoma risk factors centered around the archetypal negative immune regulator TNFAIP3/A20 in mice. Counterintuitively, B cells with moderately elevated sensitivity to stimulation caused fatal autoimmune pathology, while those with high sensitivity did not. We resolved this apparent paradox by identifying a rheostat-like cytotoxic T cell checkpoint. Cytotoxicity was instructed by and directed against B cells with high intrinsic hyperresponsiveness, while less reactive cells were spared. Removing T cell control restored a linear relationship between intrinsic B cell reactivity and lethal lymphoproliferation, lymphomagenesis, and autoinflammation. We thus identify powerful T cell-mediated negative feedback control of inherited and acquired B cell pathogenicity and define a permissive window for autoimmunity to emerge.

Comparative efficacy and safety of different recommended doses of telitacicept in patients with systemic lupus erythematosus in China: a systematic review and meta-analysis

Background

Telitacicept, a new biological agent, was approved in China for treating systemic lupus erythematosus (SLE) in 2021. Its optimal dosing for treating SLE remains unclear. Therefore, the aim of this meta-analysis is to evaluate the efficacy and safety of various telitacicept doses in SLE treatment.

Methods

PubMed, EMBASE, Cochrane libraries, Web of science, China National Knowledge Infrastructure (CNKI), VIP, Wanfang, and Sinomed were searched for the controlled trials that studied the efficacy and safety of telitacicept on SLE patients from their initiation to April 30, 2024. The analysis included three randomized controlled trials (RCT) with 606 participants. We used fixed-effects models for meta-analyses and the risk ratios (RRs) and corresponding 95% confidence intervals (CIs) to evaluate the effectiveness and safety. Heterogeneity was assessed and quantified using I2.

Results

All telitacicept dosages (80 mg, 160 mg, 240 mg) significantly improved SLE Responder Index 4 (SRI4) responses compared to the control group (RR = 2.20, 95%CI:1.50-3.21, p < 0.0001; RR = 2.18, 95%CI: 1.82-2.62, p < 0.00001; RR = 2.44, 95%CI: 1.67-3.56, p < 0.00001, respectively). The 80 mg, 160 mg, and 240 mg groups also showed better improvement on SELENA-SLE Disease Activity Index (SELENA-SLEDAI) scores (RR = 1.63, 95%CI: 1.23-2.17, p = 0.0008; RR = 1.72, 95%CI: 1.45-2.04, p < 0.00001; RR = 1.73, 95%CI: 1.30-2.30, p = 0.0002, respectively) and Physician Global Assessment (PGA) scores (RR = 1.25, 95%CI: 1.09-1.44, p = 0.002; RR = 1.39, 95%CI: 1.25-1.55, p < 0.00001; RR = 1.24, 95%CI: 1.09-1.42, p = 0.002, respectively). Furthermore, 160 mg group exhibited higher British Isles Lupus Assessment Group (BILAG) score than the control group (RR = 1.11, 95%CI: 1.01-1.22, p = 0.03). As for security, 160 mg telitacicept group had higher incidence of adverse events (AEs) than the control group (RR = 1.10, 95%CI: 1.03-1.18, p = 0.007).

Conclusion

Telitacicept combined with standard therapy presents potential benefits but there are certain safety concerns with certain dosages of telitacicept, warranting further investigation for optimal dosing strategies in SLE management.

Systematic review registration

INPLASY.COM, identifier INPLASY202440101.

LXRα agonist differentially regulates BAFF expression and biological effects in RAW264.7 cells depending on growth status: LXRα activation and BAFF signaling in RAW264.7 cells

B- cell-activating factor (BAFF), which is essential for the survival and development of B cells, is mainly produced by myeloid cells such as macrophages. Abnormal macrophage infiltration and high BAFF expression in kidney allografts are associated with the occurrence and development of antibody-mediated rejection (ABMR). Nuclear hormone receptor Liver X receptors (LXRs), is a nonnegligible participant in regulating cholesterol metabolism and inflammatory responses. Nowadays the effects of LXRα activation on macrophages have been widely studied, however the effects of LXRα activation on BAFF expression and cell function due to the change of BAFF signaling have not yet been fully investigated. In the present study, LXRα activation alone was found to downregulate BAFF expression in quiescent RAW 264.7 cells, whereas LXRα agonist significantly upregulated BAFF expression in cells pretreated with lipopolysaccharide (LPS) for 6 h. The increased BAFF signaling promoted M1 polarization and enhanced cell viability, migration, and phagocytic ability. LXRα can directly bind to the BAFF promoter region and decrease BAFF expression in RAW264.7 cells. LXRα activation enhanced mitochondrial metabolism, which promoted BAFF expression in the LPS-activated cells. Our results indicate that subtle changes in the microenvironment would affect the biological function of macrophages, in which a variety of BAFF signaling pathways may also be involved, providing a new perspective on exploring the mechanism of allograft rejection and uncovering the potential reason for the unstable efficacy of anti-BAFF preparations in kidney transplant recipients.

Real-world efficacy of belimumab in systemic lupus erythematosus: a prospective cohort from a single centre in China

OBJECTIVE

The objective of this study was to explore the efficacy and safety of belimumab among Chinese patients with SLE in a real-world setting.

METHODS

A prospective cohort study was performed, and SLE patients taking belimumab on a background of standard-of-care (SoC) treatment were consecutively enrolled from July 2021 to December 2022. Based on baseline characteristics, the patients were divided into three groups: the newly diagnosed group, the relapsed group and the refractory group. Patients in the newly diagnosed group were newly diagnosed with SLE within 4 weeks of starting belimumab. Patients in the relapse group had experienced a severe flare. Refractory patients were patients with unsatisfactory GC taper and/or disease activity control. Clinical data were collected, and disease assessments were conducted regularly. Newly diagnosed patients with SoC alone and healthy controls (HCs) were also enrolled.

RESULTS

A total of 123 SLE patients were included in the analysis, with a median follow-up period of 12 months (range 3-18 months). Thirty-three out of 123 patients were newly diagnosed, 32 had relapsed disease, and 58 had refractory disease. The SLE Responder Index 4 (SRI-4) response was achieved with good tolerance by 55.77% of patients at 3 months, 56.63% at 6 months, 63.24% at 9 months, 63.64% at 12 months and 57.14% at 18 months. Serological parameters (anti-dsDNA and C3/C4), SLEDAI-2K and daily prednisone intake were improved overall and in each group. Of the three groups, the newly diagnosed group had the highest SRI-4 rate as well as the greatest improvement in serological parameters and SLEDAI-2K. Compared with newly diagnosed patients with SoC alone, the cumulative prednisone intake of newly diagnosed patients taking belimumab was significantly decreased.

CONCLUSION

Our data supported the efficacy of belimumab in Chinese SLE patients in a real-life setting. Our study also provided new evidence indicating remarkable achievement of the SRI-4 response during belimumab therapy in newly diagnosed SLE patients.

CAR T-cell therapy for systemic lupus erythematosus: current status and future perspectives

Systemic lupus erythematosus (SLE) and lupus nephritis (LN) are debilitating autoimmune disorders characterized by pathological autoantibodies production and immune dysfunction, causing chronic inflammation and multi-organ damage. Despite current treatments with antimalarial drugs, glucocorticoids, immunosuppressants, and monoclonal antibodies, a definitive cure remains elusive, highlighting an urgent need for novel therapeutic strategies. Recent studies indicate that chimeric antigen receptor T-cell (CAR-T) therapy has shown promising results in treating B-cell malignancies and may offer a significant breakthrough for non-malignant conditions like SLE. In this paper, we aim to provide an in-depth analysis of the advancements in CAR-T therapy for SLE, focusing on its potential to revolutionize treatment for this complex disease. We explore the fundamental mechanisms of CAR-T cell action, the rationale for its application in SLE, and the immunological underpinnings of the disease. We also summarize clinical data on the safety and efficacy of anti-CD19 and anti-B cell maturation antigen (BCMA) CAR-T cells in targeting B-cells in SLE. We discuss the clinical implications of these findings and the potential for CAR-T therapy to improve outcomes in severe or refractory SLE cases. The integration of CAR-T therapy into the SLE treatment paradigm presents a new horizon in autoimmunity research and clinical practice. This review underscores the need for continued exploration and optimization of CAR-T strategies to address the unmet needs of SLE patients.

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.

Advances in B Cell Targeting for Treating Muscle-Specific Tyrosine Kinase-Associated Myasthenia Gravis

Myasthenia gravis (MG) is a typical autoimmune disease of the nervous system. It is characterized by skeletal muscle weakness and fatigue due to impaired neuromuscular junction transmission mediated by IgG autoantibodies. Muscle-specific receptor tyrosine kinase-associated MG (MuSK-MG), a rare and severe subtype of MG, is distinguished by the presence of anti-MuSK antibodies; it responds poorly to traditional therapies. Recent research on MuSK-MG treatment has focused on specific targeted therapies. Since B cells play a critical pathogenic role in producing autoantibodies and inflammatory mediators, they are often considered the preferred target for treating MuSK-MG. Currently, various B cell-targeted drugs have been developed to treat MuSK-MG; they have shown good therapeutic effects. This review explores the evolving landscape of B cell-targeted therapies in MuSK-MG, focusing on their mechanisms, efficacy, and safety, and the current limitations associated with their use. We discuss current B cell-targeted therapies aimed at depleting or modulating B cells via both direct and indirect approaches. Furthermore, we focus on novel and promising strategies such as Chimeric Autoantibody Receptor T cell therapy, which explicitly targets MuSK-specific B cells without compromising general humoral immunity. Finally, this review provides an outlook on the potential benefits and limitations of B cell-targeted therapy in developing new therapies for MuSK-MG. We conclude by discussing future research efforts needed to optimize these therapies, expand treatment options, and improve long-term outcomes in MuSK-MG management.

The Latest Progress in the Application of Telitacicept in Autoimmune Diseases

Introduction

Humoral immunity plays a key role in the pathogenesis of autoimmune diseases, and B-lymphocyte activating factor (BAFF) and a proliferation-inducing ligand (APRIL) are essential for the maintenance of B-lymphocyte reservoirs and humoral immunity. In March 2021, telitacicept, the world's first dual target three-channel biologic, was approved in China for the treatment of SLE and is currently in clinical trials exploring multiple indications for other autoimmune diseases.

Areas Covered

This article summarizes the mechanism of action, pharmacokinetics, and clinical efficacy of telitacicept for the treatment of multiple autoimmune diseases.

Expert Opinion

So far, the efficacy and safety of telitacicept in autoimmune diseases have been fully demonstrated in clinical practice. There are still many unresolved issues regarding the timing of initiation and discontinuation, still needs to be evaluated in future studies.

Serum BAFF levels are associated with the prognosis of idiopathic membranous nephropathy

OBJECTIVE

High serum levels of B-cell activation factor (BAFF) and a proliferation-inducing ligand (APRIL) have been observed in patients with idiopathic membranous nephropathy (iMN); however, their relationships with disease severity and progression remain unclear.

METHODS

Patients with iMN diagnosed via renal biopsy were enrolled in this study. The concentrations of BAFF and APRIL were determined using ELISA kits. Proteinuria remission, including complete remission (CR) and partial remission (PR), and renal function deterioration were defined as clinical events. The Cox proportional hazards method was used to analyze the relationship between cytokine levels and disease progression.

RESULTS

Seventy iMN patients were enrolled in this study, with a median follow-up time of 24 months (range 6-72 months). The serum levels of BAFF and APRIL were higher in iMN patients than in healthy controls but lower than those in minimal change disease (MCD) patients. The serum BAFF level was positively correlated with the serum APRIL level, serum anti-phospholipase A2 receptor (anti-PLA2R) antibody level, and 24-h proteinuria and negatively correlated with the serum albumin (ALB) level. However, no significant correlation was observed between the serum APRIL level and clinical parameters. According to the multivariate Cox proportional hazards regression model adjusted for sex, age, systolic blood pressure (SBP), estimated glomerular filtration rate (eGFR), immunosuppressive agent use, 24-h proteinuria, APRIL level, and anti-PLA2R antibody, only the serum BAFF level was identified as an independent predictor of PR (HR, 0.613; 95% CI, 0.405-0.927; p = 0.021) and CR of proteinuria (HR, 0.362; 95% CI, 0.202-0.648; p < 0.001).

CONCLUSIONS

A high serum BAFF level is associated with severe clinical manifestations and poor disease progression in patients with iMN.

The molecular subtypes of autoimmune diseases

Autoimmune diseases (ADs) are characterized by their complexity and a wide range of clinical differences. Despite patients presenting with similar symptoms and disease patterns, their reactions to treatments may vary. The current approach of personalized medicine, which relies on molecular data, is seen as an effective method to address the variability in these diseases. This review examined the pathologic classification of ADs, such as multiple sclerosis and lupus nephritis, over time. Acknowledging the limitations inherent in pathologic classification, the focus shifted to molecular classification to achieve a deeper insight into disease heterogeneity. The study outlined the established methods and findings from the molecular classification of ADs, categorizing systemic lupus erythematosus (SLE) into four subtypes, inflammatory bowel disease (IBD) into two, rheumatoid arthritis (RA) into three, and multiple sclerosis (MS) into a single subtype. It was observed that the high inflammation subtype of IBD, the RA inflammation subtype, and the MS "inflammation & EGF" subtype share similarities. These subtypes all display a consistent pattern of inflammation that is primarily driven by the activation of the JAK-STAT pathway, with the effective drugs being those that target this signaling pathway. Additionally, by identifying markers that are uniquely associated with the various subtypes within the same disease, the study was able to describe the differences between subtypes in detail. The findings are expected to contribute to the development of personalized treatment plans for patients and establish a strong basis for tailored approaches to treating autoimmune diseases.

Double-filtration plasmapheresis reduces type I interferon bioavailability and inducing activity in systemic lupus erythematosus

Type I interferons (IFN-Is) play a significant role in systemic lupus erythematosus (SLE) pathogenesis. Double-filtration plasmapheresis (DFPP) is a treatment option for SLE; however, its effect on IFN-Is remains unclear. Therefore, we investigated the effects of DFPP on IFN-Is. Plasma from patients with SLE (n = 11) who regularly underwent DFPP was analysed using a cell-based reporter system to detect the bioavailability and inducing activity of IFN-I. The concentration of plasma dsDNA was measured, and western blotting analysis was used to assess the phosphorylation of the STING pathway. A higher IFN-I bioavailability and inducing activity were observed in patients compared to healthy controls, and both parameters decreased after DFPP. The reduction in IFN-I-inducing activity was particularly prominent in patients with high disease activity. Notably, this reduction was not observed in STING-knockout reporter cells. Additionally, plasma dsDNA levels decreased after DFPP treatment, suggesting that inhibition of the STING pathway was responsible for the observed decrease in activity. Western blotting analysis revealed suppression of STING pathway phosphorylation after DFPP. DFPP reduced IFN-I bioavailability and the inducing activity of plasma. This reduction is likely attributable to the inhibition of the STING pathway through the elimination of dsDNA.

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.

Targeting the TNF and TNFR superfamilies in autoimmune disease and cancer

The first anti-tumour necrosis factor (TNF) monoclonal antibody, infliximab (Remicade), celebrated its 25th anniversary of FDA approval in 2023. Inhibitors of TNF have since proved clinically efficacious at reducing inflammation associated with several autoimmune diseases, including rheumatoid arthritis, psoriasis and Crohn's disease. The success of TNF inhibitors raised unrealistic expectations for targeting other members of the TNF superfamily (TNFSF) of ligands and their receptors, with difficulties in part related to their more limited, variable expression and potential redundancy. However, there has been a resurgence of interest and investment, with many of these cytokines or their cognate receptors now under clinical investigation as targets for modulation of autoimmune and inflammatory diseases, as well as cancer. This Review assesses TNFSF-targeted biologics currently in clinical development for immune system-related diseases, highlighting ongoing challenges and future directions.

Split-design approach enhances the therapeutic efficacy of ligand-based CAR-T cells against multiple B-cell malignancies

To address immune escape, multi-specific CAR-T-cell strategies use natural ligands that specifically bind multiple receptors on malignant cells. In this context, we propose a split CAR design comprising a universal receptor expressed on T cells and ligand-based switch molecules, which preserves the natural trimeric structure of ligands like APRIL and BAFF. Following optimization of the hinges and switch labeling sites, the split-design CAR-T cells ensure the native conformation of ligands, facilitating the optimal formation of immune synapses between target cancer cells and CAR-T cells. Our CAR-T-cell strategy demonstrates antitumor activities against various B-cell malignancy models in female mice, potentially preventing immune escape following conventional CAR-T-cell therapies in the case of antigen loss or switching. This ligand-based split CAR design introduces an idea for optimizing CAR recognition, enhancing efficacy and potentially improving safety in clinical translation, and may be broadly applicable to cellular therapies based on natural receptors or ligands.

Systemic lupus erythematosus: pathogenesis and targeted therapy

Systemic lupus erythematosus (SLE) is a multifaceted autoimmune disorder characterized by dysregulated immune responses and autoantibody production, which affects multiple organs and varies in clinical presentation and disease severity. The development of SLE is intricate, encompassing dysregulation within the immune system, a collapse of immunological tolerance, genetic susceptibilities to the disease, and a variety of environmental factors that can act as triggers. This review provides a comprehensive discussion of the pathogenesis and treatment strategies of SLE and focuses on the progress and status of traditional and emerging treatment strategies for SLE. Traditional treatment strategies for SLE have mainly employed non-specific approaches, including cytotoxic and immunosuppressive drugs, antimalarials, glucocorticoids, and NSAIDs. These strategies are effective in mitigating the effects of the disease, but they are not a complete cure and are often accompanied by adverse reactions. Emerging targeted therapeutic drugs, on the other hand, aim to control and treat SLE by targeting B and T cells, inhibiting their activation and function, as well as the abnormal activation of the immune system. A deeper understanding of the pathogenesis of SLE and the exploration of new targeted treatment strategies are essential to advance the treatment of this complex autoimmune disease.

Antiphospholipid Antibodies as Key Players in Systemic Lupus Erythematosus: The Relationship with Cytokines and Immune Dysregulation

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by an overproduction of cytokines, such as interleukins and interferons, contributing to systemic inflammation and tissue damage. Antiphospholipid syndrome is a thrombo-inflammatory autoimmune disease affecting a third of SLE patients. We performed an in-depth analysis of the available literature, and we highlighted the complex interplay between immunity, inflammation, and thrombosis, the three major pathogenic pathways that are trapped in a mutually reinforcing destructive loop.

Progress of rituximab in the treatment of systemic lupus erythematosus and lupus nephritis

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with heterogeneous clinical manifestations, often leading to significant morbidity and mortality, particularly due to lupus nephritis (LN). The standard therapeutic approach involving mycophenolate mofetil, cyclophosphamide, and glucocorticoids has shown limitations due to cumulative toxicity and side effects. The introduction of biologic agents, especially rituximab (RTX), a chimeric monoclonal antibody targeting CD20+ B cells, has revolutionized the treatment landscape. This review synthesized the current understanding of B cells' role in SLE and LN and evaluates RTX's therapeutic impact. B cells contribute to disease pathogenesis through autoantibody production and immune complex formation, leading to tissue damage. RTX's mechanisms of action, including Complement-Dependent cytotoxicity (CDC), antibody-dependent cell-mediated cytotoxicity (ADCC), and induction of apoptosis, have demonstrated efficacy in both SLE and LN treatment. Clinical studies have reported remission rates and improved renal outcomes with RTX use, although challenges such as human anti-chimeric antibody development and optimal dosing persist. The review emphasized the need for continued research to elucidate RTX's long-term benefits and risks, and to explore personalized treatment strategies that incorporate B cell biology for better disease management in SLE and LN.

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.

Immune-mediating and immunosuppressive pharmacotherapies for proliferative lupus nephritis

INTRODUCTION

Proliferative lupus nephritis is a common and severe complication of systemic lupus erythematosus. Affected patients are at an increased risk of developing chronic kidney disease, end-stage kidney disease, and extra-renal comorbidities. In recent years, the prognosis for patients with proliferative lupus nephritis has improved thanks to advancements in management regimens. Despite these advances, lupus nephritis continues to present therapeutic complexities and unmet needs.

AREAS COVERED

Research was conducted across major databases to identify the most relevant articles pertaining to immune-mediating and immunosuppressive therapies in lupus nephritis.

EXPERT OPINION

The prognosis for patients with proliferative lupus nephritis remains severe. Some drugs used in this disease may be unable to control activity, and most of them have a low therapeutic index and may cause severe and life-threatening side effects. Nonetheless, better management of traditional drugs and the introduction of novel therapies have improved renal prognosis and reduced local and systemic adverse events in patients with proliferative lupus nephritis.

Neutrophil extracellular traps in homeostasis and disease

Neutrophil extracellular traps (NETs), crucial in immune defense mechanisms, are renowned for their propensity to expel decondensed chromatin embedded with inflammatory proteins. Our comprehension of NETs in pathogen clearance, immune regulation and disease pathogenesis, has grown significantly in recent years. NETs are not only pivotal in the context of infections but also exhibit significant involvement in sterile inflammation. Evidence suggests that excessive accumulation of NETs can result in vessel occlusion, tissue damage, and prolonged inflammatory responses, thereby contributing to the progression and exacerbation of various pathological states. Nevertheless, NETs exhibit dual functionalities in certain pathological contexts. While NETs may act as autoantigens, aggregated NET complexes can function as inflammatory mediators by degrading proinflammatory cytokines and chemokines. The delineation of molecules and signaling pathways governing NET formation aids in refining our appreciation of NETs' role in immune homeostasis, inflammation, autoimmune diseases, metabolic dysregulation, and cancer. In this comprehensive review, we delve into the multifaceted roles of NETs in both homeostasis and disease, whilst discussing their potential as therapeutic targets. Our aim is to enhance the understanding of the intricate functions of NETs across the spectrum from physiology to pathology.

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.

Targeting chronic lymphocytic leukemia with B-cell activating factor receptor CAR T cells

The challenge of disease relapsed/refractory (R/R) remains a therapeutic hurdle in chimeric antigen receptor (CAR) T-cell therapy, especially for hematological diseases, with chronic lymphocytic leukemia (CLL) being particularly resistant to CD19 CAR T cells. Currently, there is no approved CAR T-cell therapy for CLL patients. In this study, we aimed to address this unmet medical need by choosing the B-cell activating factor receptor (BAFF-R) as a promising target for CAR design against CLL. BAFF-R is essential for B-cell survival and is consistently expressed on CLL tumors. Our research discovered that BAFF-R CAR T-cell therapy exerted the cytotoxic effects on both CLL cell lines and primary B cells derived from CLL patients. In addition, the CAR T cells exhibited cytotoxicity against CD19-knockout CLL cells that are resistant to CD19 CAR T therapy. Furthermore, we were able to generate BAFF-R CAR T cells from small blood samples collected from CLL patients and then demonstrated the cytotoxic effects of these patient-derived CAR T cells against autologous tumor cells. Given these promising results, BAFF-R CAR T-cell therapy has the potential to meet the long-standing need for an effective treatment on CLL patients.

Tertiary lymphoid structures in diseases: immune mechanisms and therapeutic advances

Tertiary lymphoid structures (TLSs) are defined as lymphoid aggregates formed in non-hematopoietic organs under pathological conditions. Similar to secondary lymphoid organs (SLOs), the formation of TLSs relies on the interaction between lymphoid tissue inducer (LTi) cells and lymphoid tissue organizer (LTo) cells, involving multiple cytokines. Heterogeneity is a distinguishing feature of TLSs, which may lead to differences in their functions. Growing evidence suggests that TLSs are associated with various diseases, such as cancers, autoimmune diseases, transplant rejection, chronic inflammation, infection, and even ageing. However, the detailed mechanisms behind these clinical associations are not yet fully understood. The mechanisms by which TLS maturation and localization affect immune function are also unclear. Therefore, it is necessary to enhance the understanding of TLS development and function at the cellular and molecular level, which may allow us to utilize them to improve the immune microenvironment. In this review, we delve into the composition, formation mechanism, associations with diseases, and potential therapeutic applications of TLSs. Furthermore, we discuss the therapeutic implications of TLSs, such as their role as markers of therapeutic response and prognosis. Finally, we summarize various methods for detecting and targeting TLSs. Overall, we provide a comprehensive understanding of TLSs and aim to develop more effective therapeutic strategies.

Lupus Nephritis from Pathogenesis to New Therapies: An Update

Lupus Nephritis (LN) still represents one of the most severe complications of Systemic Lupus Erythematosus (SLE) and a major risk factor for morbidity and mortality. However, over the last few years, several studies have paved the way for a deeper understanding of its pathogenetic mechanisms and more targeted treatments. This review aims to provide a comprehensive update on progress on several key aspects in this setting: pathogenetic mechanisms of LN, including new insight into the role of autoantibodies, complement, vitamin D deficiency, and interaction between infiltrating immune cells and kidney resident ones; the evolving role of renal biopsy and biomarkers, which may integrate information from renal histology; newly approved drugs such as voclosporin (VOC) and belimumab (BEL), allowing a more articulate strategy for induction therapy, and other promising phase III-immunosuppressive (IS) agents in the pipeline. Several adjunctive treatments aimed at reducing cardiovascular risk and progression of chronic renal damage, such as antiproteinuric agents, represent an important complement to IS therapy. Furthermore, non-pharmacological measures concerning general lifestyle and diet should also be adopted when managing LN. Integrating these therapeutic areas requires an effort towards a holistic and multidisciplinary approach. At the same time, the availability of an increasingly wider armamentarium may translate into improvements in patient's renal outcomes over the next decades.

Belimumab-induced periungual pyogenic granulomas: A case report

Pyogenic granuloma (PG) is a benign vascular neoformation, presenting as a painful red nodule on the skin, mucosa or nail apparatus. It is usually related to local complications such as bleedings and superinfections. The etiology of PG remains still unclear, and several triggers can lead to its formation. In case of multiple lesions, systemic conditions and drugs remain the main causes. Antineoplastic treatments, retinoids, antiretrovirals, hormones and anticonvulsants are frequently implicated in PG formation. In literature, PG has been rarely described in the course of biological treatment due to rheumatological disease. The present case report describes the development of polydactolous PGs in a 21-year-old woman with juvenile systemic lupus erythematosus (jSLE) during treatment with belimumab, a monoclonal antibody directed against BlyS. The clinical presentation, in particular the timing and the multiplicity of the lesions, and the improvement after belimumab discontinuation allowed us to consider PG as drug-induced. This case highlights the importance of considering PG as a potential complication of rheumatologic treatments.

Real-world efficacy of belimumab in achieving remission or low-disease activity in systemic lupus erythematosus: A retrospective study

OBJECTIVES

We investigated the effect of belimumab (BEL) on achieving low disease activity (LDA) and remission as an additive molecular-targeting agent to standard of care (SoC) in patients with systemic lupus erythematosus (SLE).

METHODS

Clinical information was retrospectively collected from patients with SLE who received BEL additive to SoC (BEL + SoC), and from patients treated with SoC alone as a control arm. Disease activity was measured by SLE-disease activity score (SLE-DAS). The proportion of patients in LDA and remission at 12 months was compared after propensity score matching. The factors contributing to LDA and remission achievement were identified by Cox proportional hazard model.

RESULTS

BEL + SoC significantly reduced SLE-DAS at 6 months, with a significantly higher proportion of patients achieving LDA and remission at 12 months compared to SoC alone. The presence of arthritis at baseline was significantly associated with achieving LDA and remission. Additionally, both treatment groups experienced a significant reduction in daily glucocorticoid dose.

CONCLUSIONS

Adding BEL to SoC was beneficial for patients with arthritis, leading to higher proportion of achieving LDA and remission, while also reducing their glucocorticoid dose. Our results indicate the utility of BEL in a treat-to-target approach for SLE patients in a real-world setting.

Efficacy and safety of telitacicept therapy in systemic lupus erythematosus with hematological involvement

OBJECTIVE

To evaluate the efficacy and safety of telitacicept in SLE patients specifically with hematological involvement.

METHOD

A total of 22 patients with SLE and hematological involvement were included in this study. These patients received telitacicept in addition to standard therapy. We compared their demographic characteristics, clinical manifestations, and laboratory indicators before and after the administration of telitacicept.

RESULTS

A total of 22 patients received telitacicept treatment for a median duration of 10.4 months (ranging from 6 to 19 months). Following telitacicept therapy, significant improvements were observed in various parameters compared to baseline. Specifically, white blood cell count increased from (3.98 ± 1.80) 109/L to (6.70 ± 2.47) 109/L, (P = 0.002), hemoglobin levels increased from (100 ± 19) g/L to (125 ± 22) g/L, (P < 0.001), and platelet count increased from (83 ± 60) 109/L to (161 ± 81) 109/L, (P = 0.004). SLE Disease Activity Index (SLEDAI) scores decreased from 12(5,15) to 0(0,4), (P < 0.001). Additionally, C3 and C4 levels showed improvement. Telitacicept treatment also resulted in a significant reduction in serum IgG levels and daily prednisone dosage. Only one adverse event (4.5%) was reported during the treatment, which was a urinary tract infection.

CONCLUSION

The combination of telitacicept and standard treatment demonstrated significant improvements in anemia, as well as increased leukocyte and platelet levels in patients with SLE and hematological involvement. Importantly, the observed adverse events were manageable and controllable. Key Points • Telitacicept effectively improves anemia, clinical outcomes, and increases leukocyte and platelet counts. • Treatment with telitacicept leads to decreased levels of lgG, IgA, anti-dsDNA, and SLEDAI scores, while serum complement C3 and C4 returned to normal. • During the follow-up period there were observed changes in individual parameters, clinical symptoms, and organ involvement, all without significant adverse events.

The bidirectional relationship of depression and disturbances in B cell homeostasis: Double trouble

Major depressive disorder (MDD) is a recurrent, persistent, and debilitating neuropsychiatric syndrome with an increasing morbidity and mortality, representing the leading cause of disability worldwide. The dysregulation of immune systems (including innate and adaptive immune systems) has been identified as one of the key contributing factors in the progression of MDD. As the main force of the humoral immunity, B cells have an essential role in the defense against infections, antitumor immunity and autoimmune diseases. Several recent studies have suggested an intriguing connection between disturbances in B cell homeostasis and the pathogenesis of MDD, however, the B-cell-dependent mechanism of MDD remains largely unexplored compared to other immune cells. In this review, we provide an overview of how B cell abnormality regulates the progression of MMD and the potential consequence of the disruption of B cell homeostasis in patients with MDD. Abnormalities of B-cell homeostasis not only promote susceptibility to MDD, but also lead to an increased risk of developing infection, malignancy and autoimmune diseases in patients with MDD. A better understanding of the contribution of B cells underlying MDD would provide opportunities for identification of more targeted treatment approaches and might provide an overall therapeutic benefit to improve the long-term outcomes of patients with MDD.

Effects of porcine epidemic diarrhea virus infection on CD21+ B cells activation

Porcine epidemic diarrhea virus (PEDV) is a devastating pathogen of acute- gastrointestinal infectious diseases, which can cause vomiting, diarrhea, dehydration and high morbidity and mortality among neonatal piglets. Humoral immunity plays a vital role in the host anti-PEDV infection process, but the mechanism of PEDV-induced B-cell immune response remains unknown. In this study, the effects of PEDV infection on CD21+ B cell activation were systematically analyzed through animal experiments. Enzyme-linked immunosorbent assays (ELISA) revealed that low levels of serum-specific IgA, IgM, or IgG were detected in piglets after PEDV infection, respectively. Serum interleukin (IL)-6 levels increased significantly at 4 d after infection, and the levels of IL-4, B-cell activating factor (BAFF), interferon (IFN)-γ, transforming growth factor (TGF)-β and IL-10 decreased at 7 d after infection. Fluorescence-activated cell sorting (FACS) showed that expression levels of CD21, MHC Ⅱ, CD40, and CD38 on B cell surfaces were significantly higher. In contrast, the proportions of CD21+IgM+ B cells were decreased in peripheral blood mononuclear cells (PBMCs) from the infected piglets. No differences were found in the percentage of CD21+CD80+ and CD21+CD27+ B cells in PBMCs from the infected piglets. In addition, the number of CD21+B cells in PBMCs stimulated with PEDV in vitro was significantly lower. No significant change in the mRNA expression of BCR molecules was found while the expression levels of paired immunoglobulin-like receptor B (PIR-B), B cell adaptor molecule of 32 kDa (Bam32) and BAFF were decreased. In conclusion, our research demonstrates that virulent strains of PEDV profoundly impact B cell activation, leading to alterations in phenotypic expression and BCR signaling molecules. Furthermore, this dysregulation results in compromised specific antibody secretion and perturbed cytokine production, highlighting the intricate immunological dysfunctions induced by PEDV infection.

Rituximab alleviates pediatric systemic lupus erythematosus associated refractory immune thrombocytopenia: a case-based review

A complication of pediatric systemic lupus erythematosus (pSLE) is immune thrombocytopenia (ITP). Although corticosteroids and immunoglobulins are frequently used as preliminary treatments, some patients do not respond to them. Rituximab has been reported to be safe and effective in the treatment of pSLE complicated with refractory ITP. Research is currently underway to determine the optimal rituximab dose for these individuals. We report a case of a child with SLE-associated ITP (SLE-ITP) who was successfully treated with rituximab. Rituximab is likely the most viable therapeutic option for refractory SLE-ITP. Furthermore, a comprehensive review of the relevant literature was performed and a concise overview of the pathogenesis and available treatment modalities for pediatric patients diagnosed with SLE and concurrent ITP was provided.

Humoral immune disorders affect clinical outcomes of oral lichen planus

OBJECTIVES

The molecular characteristics of oral lichen planus (OLP) are still unclear, and it is not possible to distinguish the clinical outcome of OLP patients in a short period of time for follow-up. Here, we investigate the molecular characteristics of lesions in patients with stable lichen planus (SOLP) and recalcitrant erosive oral lichen planus (REOLP).

METHODS

Our clinical follow-up cohort was split into SOLP and REOLP groups based on the follow-up clinical data. The core modules associated with the clinical information were identified by weighted gene co-expression network analysis (WGCNA). The OLP cohort samples were divided into two groups by molecular typing, and a prediction model for OLP was created by training neural networks with the neuralnet package.

RESULTS

We screened 546 genes in five modules. After doing a molecular type of OLP, it was determined that B cells might have a significant impact on the clinical outcome of OLP. In addition, by means of machine learning, a prediction model was developed to predict the clinical regression of OLP with greater accuracy than the existing clinical diagnostic.

CONCLUSIONS

Our study revealed humoral immune disorders may make an important contribution to the clinical outcome of OLP.

Correlation Between B-Cell Activating Factor of the Tumor Necrosis Factor Family Level in Serum and Immune Inflammation in Patients with Neuropsychiatric Systemic Lupus Erythematosus and its Clinical Value

OBJECTIVE

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a form of SLE associated with severe NP syndromes causing mortality and morbidity. Respecting the fundamental of BAFF in NPSLE pathophysiology, we investigated its clinical value.

METHODS

Totally 105 NPSLE and 101 SLE cases without NPSLE (non-NPSLE, control) were included. Serum BAFF/TNF-α/IL-6/IL-10 levels were measured using ELISA kits. T lymphocytes were detected by flow cytometry. The independent influencing factors for NPSLE, and the auxiliary diagnostic efficacy and the ability of BAFF levels to predict adverse prognosis of NPSLE patients were analyzed by multiple factor logistic regression, and ROC curve and survival curve.

RESULTS

In NPSLE patients, serum BAFF level was increased and positively correlated with SLEDAI-2k, serum proinflammatory cytokines, while negatively correlated with CD4+T/CD8+T cells, and anti-inflammatory cytokine. High serum BAFF protein level was associated with a higher risk of developing NPSLE. The AUC of serum BAFF > 301.7 assisting in NPSLE diagnosis was 0.8196. Furthermore, high levels of serum BAFF were associated with a higher risk of adverse outcomes in NPSLE patients.          .

CONCLUSION

Serum BAFF level in NPSLE patients was correlated with lymphocytes and high serum BAFF protein level could assist in diagnosis and to predict adverse outcomes in NPSLE patients.

Neutrophil depletion attenuates antibody-mediated rejection in a renal transplantation mouse model

Antibody-mediated rejection (AMR) can cause graft failure following renal transplantation. Neutrophils play a key role in AMR progression, but the exact mechanism remains unclear. We investigated the effect of neutrophils on AMR in a mouse kidney transplantation model. The mice were divided into five groups: syngeneic transplantation (Syn), allograft transplantation (Allo), and three differently treated AMR groups. The AMR mouse model was established using skin grafts to pre-sensitize recipient mice. Based on the AMR model, Ly6G-specific monoclonal antibodies were administered to deplete neutrophils (NEUT-/- + AMR) and TACI-Fc was used to block B-cell-activating factor (BAFF)/a proliferation-inducing ligand (APRIL) signaling (TACI-Fc + AMR). Pathological changes were assessed using hematoxylin-eosin and immunohistochemical staining. Banff values were evaluated using the Banff 2015 criteria. Donor-specific antibody (DSA) levels were assessed using flow cytometry, and BAFF and APRIL concentrations were measured using ELISA. Compared to the Syn and Allo groups, a significantly increased number of neutrophils and increased C4d and IgG deposition were observed in AMR mice, accompanied by elevated DSA levels. Neutrophil depletion inhibited inflammatory cell infiltration and reduced C4d and IgG deposition. Neutrophil depletion significantly decreased DSA levels after transplantation and suppressed BAFF and APRIL concentrations, suggesting a mechanism for attenuating AMR-induced graft damage. Similar results were obtained after blockading BAFF/APRIL using a TACI-Fc fusion protein. In summary, neutrophil infiltration increased in the AMR mouse renal transplantation model. Neutrophil depletion or blockading the BAFF/APRIL signaling pathway significantly alleviated AMR and may provide better options for the clinical treatment of AMR.

Mapping theme evolution and identifying hotspots in biomarkers of systemic lupus erythematosus based on global research

Objective: To perform a bibliometric analysis in the field of biomarkers for systemic lupus erythematosus. Methods: Publications were from Web of Science. Microsoft Excel, VOSviewer, Science Mapping Analysis software Tool, CiteSpace and Tableau were used for analysis. Results: A total of 1112 publications were identified; 1503 institutions from 69 countries contributed, with the highest outputs from China and Karolinska University Hospital. Petri had a tremendous impact. Academic collaborations were localized. Lupus and Arthritis & Rheumatology were the top two journals in terms of publications and citations. Lymphocyte, autoantibody, type I interferon, genetic polymorphisms and urinary biomarkers have been high-frequency themes. Conclusion: Global collaboration needs to be further strengthened. Immune cell, cytokine and gene-level research as a whole and noninvasive tests are the future trends.