B-cell depletion with obinutuzumab for the treatment of proliferative lupus nephritis: a randomised, double-blind, placebo-controlled trial

Sustained depression of B cell counts in lupus nephritis after treatment with rituximab and/or belimumab is associated with fewer disease flares

OBJECTIVE

To study the risk of lupus nephritis flare (LNF) or severe lupus flare (SLF) as a function of B cell count kinetics in lupus nephritis (LN) patients after they achieve at least a partial renal response (PRR) with induction treatment that includes rituximab (RTX) and/or belimumab (BLM).

METHODS

We performed a retrospective analysis of a cohort of 19 patients with severe LN that received a B cell agent (BCA), RTX and/or BLM, as part of an initial treatment regimen for an LN flare and had subsequent CD19+ B cell measurements in peripheral blood. We then characterized the follow-up periods, after B cell depressions occurred and PRR were achieved, by the corresponding trajectories of B cell counts (BCC). Time periods with sustained low BCC were type 1 (T1) episodes, while those with repletion of BCC>100 cells/μL were called type 2 (T2) episodes. Time periods with rapid BCC repletion, defined as >50 cells/μL in ≤6 months, were called T2b episodes. Corresponding C3, C4, and anti-dsDNA levels were recorded for each episode. The time from PRR until an event, either a LNF or SLF, or to censoring, either at the end of the study period or the end of available patient follow-up, was assessed for each episode type. Kaplan-Meier survival analysis was used to compare time to flare between T1 and T2 episodes.

RESULTS

There were 26 episodes of B cell depression. Seventeen (65%) were T1 and 9 (35%) were T2. Compared to T1 episodes, T2 episodes were 9.0 times more likely to result in flare over the follow-up period (hazard ratio (HR) = 9.0, 95% CI for HR = 2.2-36.7); this risk was even larger for T2b vs T1 episodes. Median BCC was 14 cells/μL in T1 and 160 cells/μL in T2 episodes. Both C3 and C4 levels significantly increased over the duration of the episode in T1 episodes only.

CONCLUSION

Sustained low BCC was associated with prolonged serologic and clinical response, whereas repletion, and particularly rapid repletion, of B cells after treatment with BCA was associated with subsequent disease flare.

Chimeric antigen receptor T cell therapy for autoimmune disease

Infusion of T cells engineered to express chimeric antigen receptors (CARs) that target B cells has proven to be a successful treatment for B cell malignancies. This success inspired the development of CAR T cells to selectively deplete or modulate the aberrant immune responses that underlie autoimmune disease. Promising results are emerging from clinical trials of CAR T cells targeting the B cell protein CD19 in patients with B cell-driven autoimmune diseases. Further approaches are being designed to extend the application and improve safety of CAR T cell therapy in the setting of autoimmunity, including the use of chimeric autoantibody receptors to selectively deplete autoantigen-specific B cells and the use of regulatory T cells engineered to express antigen-specific CARs for targeted immune modulation. Here, we highlight important considerations, such as optimal target cell populations, CAR construct design, acceptable toxicities and potential for lasting immune reset, that will inform the eventual safe adoption of CAR T cell therapy for the treatment of autoimmune diseases.

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.

Systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multisystemic autoimmune disease characterised by the presence of autoantibodies towards nuclear antigens, immune complex deposition, and chronic inflammation at classic target organs such as skin, joints, and kidneys. Despite substantial advances in the diagnosis and management of SLE, the burden of disease remains high. It is important to appreciate the typical presentations and the diagnostic process to facilitate early referral and diagnosis for patients. In most patients, constitutional, mucocutaneous, and musculoskeletal symptoms represent the earliest complaints; these symptoms can include fatigue, lupus-specific rash, mouth ulcers, alopecia, joint pain, and myalgia. In this Seminar we will discuss a diagnostic approach to symptoms in light of the latest classification criteria, which include a systematic evaluation of clinical manifestations (weighted within each domain) and autoantibody profiles (such as anti-double-stranded DNA, anti-Sm, hypocomplementaemia, or antiphospholipid antibodies). Non-pharmacotherapy management is tailored to the individual, with specific lifestyle interventions and patient education to improve quality of life and medication (such as hydroxychloroquine or immunosuppressant) adherence. In the last decade, there have been a few major breakthroughs in approved treatments for SLE and lupus nephritis, such as belimumab, anifrolumab, and voclosporin. However the disease course remains variable and mortality unacceptably high. Access to these expensive medications has also been restricted across different regions of the world. Nonetheless, understanding of treatment goals and strategies has improved. We recognise that the main goal of treatment is the achievement of remission or low disease activity. Comorbidities due to both disease activity and treatment adverse effects, especially infections, osteoporosis, and cardiovascular disease, necessitate vigilant prevention and management strategies. Tailoring treatment options to achieve remission, while balancing treatment-related comorbidities, are priority areas of SLE management.

Advancing autoimmune Rheumatic disease treatment: CAR-T Cell Therapies - Evidence, Safety, and future directions

INTRODUCTION

Despite advancements in managing autoimmune rheumatic diseases (ARDs) with existing treatments, many patients still encounter challenges such as inadequate responses, difficulty in maintaining remission, and side effects. Chimeric Antigen Receptor (CAR) T-cell therapy, originally developed for cancer, has now emerged as a promising option for cases of refractory ARDs.

METHODS

A search of the literature was conducted to compose a narrative review exploring the current evidence, potential safety, limitations, potential modifications, and future directions of CAR-T cells in ARDs.

RESULTS

CAR-T cell therapy has been administered to patients with refractory ARDs, including systemic lupus erythematosus, antisynthetase syndrome, and systemic sclerosis, demonstrating significant improvement. Notable responses include enhanced clinical symptoms, reduced serum autoantibody titers, and sustained remissions in disease activity. Preclinical and in vitro studies using both animal and human samples also support the efficacy and elaborate on potential mechanisms of CAR-T cells against antineutrophil cytoplasmic antibody-associated vasculitis and rheumatoid arthritis. While cautious monitoring of adverse events, such as cytokine release syndrome, is crucial, the therapy appears to be highly tolerable. Nevertheless, challenges persist, including cost, durability due to potential CAR-T cell exhaustion, and manufacturing complexities, urging the development of innovative solutions to further enhance CAR-T cell therapy accessibility in ARDs.

CONCLUSIONS

CAR-T cell therapy for refractory ARDs has demonstrated high effectiveness. While no significant warning signs are currently reported, achieving a balance between therapeutic efficacy and safety is vital in adapting CAR-T cell therapy for ARDs. Moreover, there is significant potential for technological advancements to enhance the delivery of this treatment to patients, thereby ensuring safer and more effective disease control for patients.

[CAR T-cell therapy in rheumatology-What we know so far?]

Autoreactive B‑cells play a key role in the pathogenesis of autoimmune diseases, such systemic lupus erythematosus (SLE). An efficient depletion of B‑cells therefore plays a special role in autoimmune diseases, especially in cases with a severe course of the disease. Treatment with chimeric antigen receptor (CAR) T‑cells, which was originally developed for the treatment of B‑cell lymphomas and leukemias, provides the possibility to deplete B‑cells even in deep tissues. The initial results from case series with this procedure for SLE, myositis and systemic sclerosis were very positive. This review article gives an overview of the course, mechanism of action, results so far and the research agenda of CAR T‑cell therapy in autoimmune diseases.

Management of systemic lupus erythematosus: a systematic literature review informing the 2023 update of the EULAR recommendations

OBJECTIVES

To analyse the new evidence (2018-2022) for the management of systemic lupus erythematosus (SLE) to inform the 2023 update of the European League Against Rheumatism (EULAR) recommendations.

METHODS

Systematic literature reviews were performed in the Medline and the Cochrane Library databases capturing publications from 1 January 2018 through 31 December 2022, according to the EULAR standardised operating procedures. The research questions focused on five different domains, namely the benefit/harm of SLE treatments, the benefits from the attainment of remission/low disease activity, the risk/benefit from treatment tapering/withdrawal, the management of SLE with antiphospholipid syndrome and the safety of immunisations against varicella zoster virus and SARS-CoV2 infection. A Population, Intervention, Comparison and Outcome framework was used to develop search strings for each research topic.

RESULTS

We identified 439 relevant articles, the majority being observational studies of low or moderate quality. High-quality randomised controlled trials (RCTs) documented the efficacy of the type 1 interferon receptor inhibitor, anifrolumab, in non-renal SLE, and belimumab and voclosporin, a novel calcineurin inhibitor, in lupus nephritis (LN), when compared with standard of care. For the treatment of specific organ manifestations outside LN, a lack of high-quality data was documented. Multiple observational studies confirmed the beneficial effects of attaining clinical remission or low disease activity, reducing the risk for multiple adverse outcomes. Two randomised trials with some concerns regarding risk of bias found higher rates of relapse in patients who discontinued glucocorticoids (GC) or immunosuppressants in SLE and LN, respectively, yet observational cohort studies suggest that treatment withdrawal might be feasible in a subset of patients.

CONCLUSION

Anifrolumab and belimumab achieve better disease control than standard of care in extrarenal SLE, while combination therapies with belimumab and voclosporin attained higher response rates in high-quality RCTs in LN. Remission and low disease activity are associated with favourable long-term outcomes. In patients achieving these targets, GC and immunosuppressive therapy may gradually be tapered. Cite Now.

B-cell depletion in autoimmune diseases

B cells have a pivotal function in the pathogenesis of autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis and systemic lupus erythematosus. In autoimmune disease, B cells orchestrate antigen presentation, cytokine production and autoantibody production, the latter via their differentiation into antibody-secreting plasmablasts and plasma cells. This article addresses the current therapeutic strategies to deplete B cells in order to ameliorate or potentially even cure autoimmune disease. It addresses the main target antigens in the B-cell lineage that are used for therapeutic approaches. Furthermore, it summarises the current evidence for successful treatment of autoimmune disease with monoclonal antibodies targeting B cells and the limitations and challenges of these approaches. Finally, the concept of deep B-cell depletion and immunological reset by chimeric antigen receptor T cells is discussed, as well as the lessons from this approach for better understanding the role of B cells in autoimmune disease.

Causal association of plasma circulating metabolites with nephritis: a Mendelian randomization study

Background

Nephritis is a pivotal catalyst in chronic kidney disease (CKD) progression. Although epidemiological studies have explored the impact of plasma circulating metabolites and drugs on nephritis, few have harnessed genetic methodologies to establish causal relationships.

Methods

Through Mendelian randomization (MR) in two substantial cohorts, spanning large sample sizes, we evaluated over 100 plasma circulating metabolites and 263 drugs to discern their causal effects on nephritis risk. The primary analytical tool was the inverse variance weighted (IVW) analysis. Our bioinformatic scrutiny of GSE115857 (IgA nephropathy, 86 samples) and GSE72326 (lupus nephritis, 238 samples) unveiled anomalies in lipid metabolism and immunological characteristics in nephritis. Thorough sensitivity analyses (MR-Egger, MR-PRESSO, leave-one-out analysis) were undertaken to verify the instrumental variables' (IVs) assumptions.

Results

Unique lipoprotein-related molecules established causal links with diverse nephritis subtypes. Notably, docosahexaenoic acid (DHA) emerged as a protective factor for acute tubulointerstitial nephritis (ATIN) (OR1 = 0.84, [95% CI 0.78-0.90], p1 = 0.013; OR2 = 0.89, [95% CI 0.82-0.97], p2 = 0.007). Conversely, multivitamin supplementation minus minerals notably increased the risk of ATIN (OR = 31.25, [95% CI 9.23-105.85], p = 0.004). Reduced α-linolenic acid (ALA) levels due to lipid-lowering drugs were linked to both ATIN (OR = 4.88, [95% CI 3.52-6.77], p < 0.001) and tubulointerstitial nephritis (TIN) (OR = 7.52, [95% CI 2.78-20.30], p = 0.042). While the non-renal drug indivina showed promise for TIN treatment, the use of digoxin, hydroxocobalamin, and liothyronine elevated the risk of chronic tubulointerstitial nephritis (CTIN). Transcriptome analysis affirmed that anomalous lipid metabolism and immune infiltration are characteristic of IgA nephropathy and lupus nephritis. The robustness of these causal links was reinforced by sensitivity analyses and leave-one-out tests, indicating no signs of pleiotropy.

Conclusion

Dyslipidemia significantly contributes to nephritis development. Strategies aimed at reducing plasma low-density lipoprotein levels or ALA supplementation may enhance the efficacy of existing lipid-lowering drug regimens for nephritis treatment. Renal functional status should also be judiciously considered with regard to the use of nonrenal medications.

Chimeric antigen receptors: "CARs" in the fast lane for rheumatology

PURPOSE OF REVIEW

Recent advances in hematology-oncology have pioneered cell-mediated elimination of pathologic B-cell populations employing chimeric antigen receptor (CAR) T cells. In this review, we discuss recent adoption of CAR-T treatment for severe refractory autoimmune disease. We highlight unique aspects of the autoimmune model and review current clinical data regarding treatment of rheumatologic disease.

RECENT FINDINGS

To date, several CAR-Ts are FDA approved for Multiple Myeloma and B-cell malignancies and have demonstrated extraordinary clinical responses in refractory disease. Realizing the central role of B-cells in certain autoimmune diseases, CAR-T is now being explored for achieving drug-free remission induction, and potentially cure, of several rheumatologic diseases. The largest experience to date in the field of autoimmunity, building off the University Hospital Erlangen groups' earlier success treating a single patient with CD19-CAR in severe refractory SLE, Mackensen et al. enrolled five patients in a compassionate use program. Following autologous CD19-CAR T infusion, they demonstrated drug-free clinical and laboratory remission for at least 12 months in all five patients, with reconstitution of B cells expressing a naïve phenotype.

SUMMARY

CAR-T treatment has shown striking drug-free responses in severe lupus and other autoimmune diseases, creating a need for further exploration and development.

Emerging biologic therapies for systemic lupus erythematosus

PURPOSE OF REVIEW

The approval of belimumab and anifrolumab has expanded the scope of treatment for systemic lupus erythematosus (SLE) patients. However, many patients remain refractory to currently available therapies and suffer from drug toxicities. This review will discuss approved and target-specific therapeutics in development that bring hope for better SLE treatments.

RECENT FINDINGS

Since the last review on this subject in the journal, the FDA has approved anifrolumab and belimumab for SLE and lupus nephritis (LN), respectively. A fully humanized anti-CD20, obinutuzumab, met the primary end point in a phase II trial in LN. A Tyk2 inhibitor, deucravacitinib, and an antibody targeting plasmacytoid dendritic cells, litifilimab, met the primary end point in phase II trials in SLE and cutaneous lupus erythematosus (CLE). Ustekinumab and baricitinib met the primary end point in phase II but not in phase III trials.

SUMMARY

While many drug candidates which met the end points in phase II trials have failed phase III trials, the number of target-specific therapies for SLE has continued to expand.

Safety of Obinutuzumab in Children With Autoimmune Encephalitis and Early B-Cell Repopulation on Rituximab

BACKGROUND

Rituximab (RTX) resistance or early B-cells repopulation were observed in children but only few publications reported the use of Obinutuzumab and no recommendations were made concerning the dosage for children.

METHODS

This study was a single-center retrospective cohort study of all the children followed-up in the Pediatric Neurology Department of Necker-Enfants malades Hospital in Paris, France, and treated with obinutuzumab, between November 1, 2019, and November 1, 2021.

RESULTS

A total of eight children (three females, median age 4.5 years) were treated. Seven patients presented with autoimmune encephalitis and one with myeloradiculitis. The median delay of B-cell repopulation after a course of RTX was 87 days (range 41 to 160). A switch to obinutuzumab (anti-CD20) was performed for eight children. The median duration between the first RTX infusion and obinutuzumab administration was 6.6 months. The dosage regimen for obinutuzumab was one infusion of 1000 mg/1.73 m2, that is to say 580 mg/m2 (maximum 1000 mg/infusion), by extrapolation from the adult dosage. The median delay of B-cell repopulation after one course of obinutuzumab was 230 days (range 66 to 303 days) vs 87 days after one course of RTX (P < 0.01). None of the patients presented side effects with obinutuzumab treatment. All patients had a favorable evolution at the last-follow up. Median follow-up was 1.6 years.

CONCLUSIONS

This study reports the use of obinutuzumab in neurological inflammatory diseases in a pediatric population. Obinutuzumab seems to have a better biological efficacy than RTX with a longer time of B-cell repopulation.

Obinutuzumab Pretreatment as a Novel Approach to Mitigate Formation of Anti-Drug Antibodies Against Cergutuzumab Amunaleukin in Patients with Solid Tumors

PURPOSE

The immunocytokine cergutuzumab amunaleukin (CEA-IL2v) showed manageable safety and favorable pharmacodynamics in phase I/Ib trials in patients with advanced/metastatic carcinoembryonic antigen-positive (CEA+) solid tumors, but this was accompanied by a high incidence of anti-drug antibodies (ADA). We examined B-cell depletion with obinutuzumab as a potential mitigation strategy.

EXPERIMENTAL DESIGN

Preclinical data comparing B-cell depletion with rituximab versus obinutuzumab are summarized. Substudies of phase I/Ib trials investigated the effect of obinutuzumab pretreatment on ADA development, safety, pharmacodynamics, and antitumor activity of CEA-IL2v ± atezolizumab in patients with advanced/metastatic or unresectable CEA+ solid tumors who had progressed on standard of care.

RESULTS

Preclinical data showed superior B-cell depletion with obinutuzumab versus rituximab. In clinical studies, patients received CEA-IL2v monotherapy with (n = 16) or without (n = 6) obinutuzumab pretreatment (monotherapy study), or CEA-IL2v + atezolizumab + obinutuzumab pretreatment (n = 5; combination study). In the monotherapy study, after four cycles (every 2 weeks treatment), 0/15 evaluable patients administered obinutuzumab pretreatment had ADAs versus 4/6 patients without obinutuzumab. Obinutuzumab pretreatment with CEA-IL2v monotherapy showed no new safety signals and pharmacodynamic data suggested minimal impact on T cells and natural killer cells. Conversely, increased liver toxicity was observed in the combination study (CEA-IL2v + atezolizumab + obinutuzumab pretreatment).

CONCLUSIONS

These preliminary findings suggest that obinutuzumab pretreatment before CEA-IL2v administration in patients with CEA+ solid tumors may be a feasible and potent ADA mitigation strategy, with an acceptable safety profile, supporting broader investigation of obinutuzumab pretreatment for ADA mitigation in other settings.

Do we really need cyclophosphamide for lupus nephritis?

A 14-year-old patient presents with hematuria and proteinuria. Clinical evaluation reveals a positive anti-nuclear antibody titer, positive anti-double stranded DNA antibody and hypocomplementemia. Systemic lupus erythematosus (SLE) is diagnosed based on the 2019 EULAR/ACR (European League Against Rheumatism/American College of Rheumatology) classification criteria (Aringer et al. Arthritis Rheumatol 71:1400-1412, 2019). A kidney biopsy is performed that confirms the presence of immune complex glomerulonephritis, ISN-RPS (International Society of Nephrology/Renal Pathology Society) class IV (Bajema et al. Kidney Int 93:789-796, 2018). According to the latest clinical practice guidelines (Rovin et al. Kidney Int 100:753-779, 2021; Fanouriakis et al. Ann Rheum Dis 83:15-29, 2023), there are alternatives to treating this patient with cyclophosphamide. But what if this patient also presented with oliguria and volume overload requiring intensive care and dialysis? What if this patient also presented with altered mental status and seizures, and was diagnosed with neuropsychiatric lupus? What if this patient was also diagnosed with a pulmonary hemorrhage and respiratory failure? The clinical practice guidelines do not address these scenarios that are not uncommon in patients with SLE. Moreover, in some countries worldwide, patients do not have the privilege of access to biologics or more expensive alternatives. The purpose of this review is to evaluate the contemporary options for initial treatment of nephritis in patients with SLE.

Improving Kidney Disease Care: One Giant Leap for Nephrology

Nephrology is an ever-evolving field of medicine. The importance of such a discipline is related to the high clinical impact of kidney disease. In fact, abnormalities of kidney function and/or structure are common in the general population, reaching an overall prevalence of about 10%. More importantly, the onset of kidney damage is related to a strikingly high risk of cardiovascular events, mortality, and progression to kidney failure which, in turn, compromises quality and duration of life. Attempts to comprehend the pathogenesis and molecular mechanisms involved in kidney disease occurrence have prompted the development and implementation of novel drugs in clinical practice with the aim of treating the 'specific cause' of kidney disease (including chronic kidney disease, glomerular disease, and genetic kidney disorders) and the main immunological complications following kidney transplantation. Herein, we provide an overview of the principal emerging drug classes with proved efficacy in the context of the aforementioned clinical conditions. This can represent a simplified guide for clinical nephrologists to remind them of the vast and heterogeneous armamentarium of drugs that should be used in the present and the future to improve the management of patients suffering from kidney disease.

Targeting pathogenic CD8+ tissue-resident T cells with chimeric antigen receptor therapy in murine autoimmune cholangitis

Primary biliary cholangitis (PBC) is a cholestatic autoimmune liver disease characterized by autoreactive T cell response against intrahepatic small bile ducts. Here, we use Il12b-/-Il2ra-/- mice (DKO mice) as a model of autoimmune cholangitis and demonstrate that Cd8a knockout or treatment with an anti-CD8α antibody prevents/reduces biliary immunopathology. Using single-cell RNA sequencing analysis, we identified CD8+ tissue-resident memory T (Trm) cells in the livers of DKO mice, which highly express activation- and cytotoxicity-associated markers and induce apoptosis of bile duct epithelial cells. Liver CD8+ Trm cells also upregulate the expression of several immune checkpoint molecules, including PD-1. We describe the development of a chimeric antigen receptor to target PD-1-expressing CD8+ Trm cells. Treatment of DKO mice with PD-1-targeting CAR-T cells selectively depleted liver CD8+ Trm cells and alleviated autoimmune cholangitis. Our work highlights the pathogenic role of CD8+ Trm cells and the potential therapeutic usage of PD-1-targeting CAR-T cells.

Predictors and prognostic factors influencing outcomes of anti-CD20 monoclonal antibodies in systemic lupus erythematosus: A systematic review update

BACKGROUND

Anti-C20 monoclonal antibodies (MAb), such as rituximab, are commonly used for the treatment of patients with severe or refractory systemic lupus erythematosus (SLE) but clinical outcomes are highly variable. We aimed to provide an update of a systematic review of predictive and prognostic factors of anti-CD20 MAb treatment in SLE.

METHODS

A systematic literature search was undertaken to identify predictive and prognostic factors of clinical response following treatment with anti-CD20 therapies in SLE patients. Studies examining rituximab published prior to 2015 were excluded. Risk of bias was assessed for randomized controlled trials (RCTs) using the Cochrane Collaboration (RoB2) tool for RCTs and the Quality In Prognosis Studies Tool (QUIPS) for cohort studies. A narrative synthesis of the evidence was undertaken and quality of evidence (QoE) was assessed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

From 850 studies identified, 17 studies met the inclusion criteria. A further 8 studies were identified and included through search updates. There were two post-hoc analyses of RCTs of rituximab, one RCT of ocrelizumab and one of obinutuzumab; and 16 cohort studies examining rituximab treatment. The overall QoE was low or very low. There was wide heterogeneity in definitions of clinical disease activity and outcome measures, non-standardized laboratory cut-offs, failure to account for confounders and multiple subgroup analyses of differing outcomes. B cell depletion as well as novel biomarkers, such as S100 proteins, FCGR genotype, anti-vimentin and anti-drug antibodies showed some evidence of prognostic value but QoE was limited due to moderate to high risk of bias, early phase of investigation and imprecision of results.

CONCLUSION

There has been no validation of previously identified prognostic factors to guide outcome in anti-CD20 treated lupus patients. Hypothesis-driven studies of several novel markers however, demonstrate prognostic value and require replication and validation to support their use in routine clinical practice.

PROSPERO REGISTRATION NUMBER

CRD42020220339.

CD19 Chimeric Antigen Receptor T Cell Treatment: Unraveling the Role of B Cells in Systemic Lupus Erythematosus

B cell generation of autoantibodies is a crucial step in the pathogenesis of systemic lupus erythematosus (SLE). After their differentiation in the bone marrow, B cells populate the secondary lymphatic organs, where they undergo further maturation leading to the development of memory B cells as well as antibody-producing plasmablasts and plasma cells. Targeting B cells is an important strategy to treat autoimmune diseases such as SLE, in which B cell tolerance is disturbed and autoimmune B cells and autoantibodies emerge. This review discusses the functional aspects of antibody- and cell-based B cell-depleting therapy in SLE. It thereby particularly focuses on lessons learned from chimeric antigen receptor (CAR) T cell treatment on the role of B cells in SLE for understanding B cell pathology in SLE. CAR T cells model a deep B cell depletion and thereby allow understanding the role of aberrant B cell activation in the pathogenesis of SLE. Furthermore, the effects of B cell depletion on autoantibody production can be better described, ie, explaining the concept of different cellular sources of (auto-) antibodies in the form of short-lived plasmablasts and long-lived plasma cells, which differ in their susceptibility to B cell depletion and require different targeted therapeutic approaches. Finally, the safety of deep B cell depletion in autoimmune disease is discussed.

Emerging therapeutic targets in systemic sclerosis

Systemic sclerosis is an autoimmune connective tissue disease which is characterised by vascular perturbations, inflammation, and fibrosis. Although huge progress recently into the underlying molecular pathways that are perturbed in the disease, currently no therapy exists that targets the fibrosis element of the disease and consequently there is a huge unmet medical need. Emerging studies reveal new dimensions of complexity, and multiple aberrant pathways have been uncovered that have shed light on disturbed signalling in the disease, primarily in inflammatory pathways that can be targeted with repurposed drugs. Pre-clinical animal models using these inhibitors have yielded proof of concept for targeting these signalling systems and progressing to clinical trials. This review will examine the recent evidence of new perturbed pathways in SSc and how these can be targeted with new or repurposed drugs to target a currently intractable disease.

Noninvasive biomarkers for lupus nephritis

Lupus nephritis (LN) is one of the most severe clinical manifestations of systemic lupus erythematosus (SLE). Notably, the clinical manifestations of LN are not always consistent with the histopathological findings. Therefore, the diagnosis and activity monitoring of this disease are challenging and largely depend on invasive renal biopsy. Renal biopsy has side effects and is associated with the risk of bleeding and infection. There is a growing interest in the development of novel noninvasive biomarkers for LN. In this review, we summarize most of the LN biomarkers discovered so far by correlating current knowledge with future perspectives. These biomarkers fundamentally reflect the biological processes of kidney damage and repair during disease. Furthermore, this review highlights the role of urinary cell phenotype detection in the diagnosis, monitoring, and treatment of LN and summarizes the limitations and countermeasures of this test.

Novel and potential future therapeutic options in systemic autoimmune diseases

Autoimmune inflammation is caused by the loss of tolerance to specific self-antigens and can result in organ-specific or systemic disorders. Systemic autoimmune diseases affect a significant portion of the population with an increasing rate of incidence, which means that is essential to have effective therapies to control these chronic disorders. Unfortunately, several patients with systemic autoimmune diseases do not respond at all or just partially respond to available conventional synthetic disease-modifying antirheumatic drugs and targeted therapies. However, during the past few years, some new medications have been approved and can be used in real-life clinical settings. Meanwhile, several new candidates appeared and can offer promising novel treatment options in the future. Here, we summarize the newly available medications and the most encouraging drug candidates in the treatment of systemic lupus erythematosus, rheumatoid arthritis, Sjögren's disease, systemic sclerosis, systemic vasculitis, and autoimmune myositis.

Reciprocal regulation of SIRT1 and AMPK by Ginsenoside compound K impedes the conversion from plasma cells to mitigate for podocyte injury in MRL/lpr mice in a B cell-specific manner

Background

Deposition of immune complexes drives podocyte injury acting in the initial phase of lupus nephritis (LN), a process mediated by B cell involvement. Accordingly, targeting B cell subsets represents a potential therapeutic approach for LN. Ginsenoside compound K (CK), a bioavailable component of ginseng, possesses nephritis benefits in lupus-prone mice; however, the underlying mechanisms involving B cell subpopulations remain elusive.

Methods

Female MRL/lpr mice were administered CK (40 mg/kg) intragastrically for 10 weeks, followed by measurements of anti-dsDNA antibodies, inflammatory chemokines, and metabolite profiles on renal samples. Podocyte function and ultrastructure were detected. Publicly available single-cell RNA sequencing data and flow cytometry analysis were employed to investigate B cell subpopulations. Metabolomics analysis was adopted. SIRT1 and AMPK expression were analyzed by immunoblotting and immunofluorescence assays.

Results

CK reduced proteinuria and protected podocyte ultrastructure in MRL/lpr mice by suppressing circulating anti-dsDNA antibodies and mitigating systemic inflammation. It activated B cell-specific SIRT1 and AMPK with Rhamnose accumulation, hindering the conversion of renal B cells into plasma cells. This cascade facilitated the resolution of local renal inflammation. CK facilitated the clearance of deposited immune complexes, thus reinstating podocyte morphology and mobility by normalizing the expression of nephrin and SYNPO.

Conclusions

Our study reveals the synergistic interplay between SIRT1 and AMPK, orchestrating the restoration of renal B cell subsets. This process effectively mitigates immune complex deposition and preserves podocyte function. Accordingly, CK emerges as a promising therapeutic agent, potentially alleviating the hyperactivity of renal B cell subsets during LN.

Managing Lupus Nephritis in Children and Adolescents

Lupus nephritis is an important manifestation of systemic lupus erythematosus, which leads to chronic kidney disease, kidney failure, and can result in mortality. About 35%-60% of children with systemic lupus erythematosus develop kidney involvement. Over the past few decades, the outcome of patients with lupus nephritis has improved significantly with advances in immunosuppressive therapies and clinical management. Nonetheless, there is a paucity of high-level evidence to guide the management of childhood-onset lupus nephritis, because of the relatively small number of patients at each centre and also because children and adolescents are often excluded from clinical trials. Children and adults differ in more ways than just size, and there are remarkable differences between childhood- and adult-onset lupus nephritis in terms of disease severity, treatment efficacy, tolerance to medications and most importantly, psychosocial perspective. In this article, we review the 'art and science' of managing childhood-onset lupus nephritis, which has evolved in recent years, and highlight special considerations in this specific patient population.

A new therapeutic target for systemic lupus erythematosus: the current landscape for drug development of a toll-like receptor 7/8 antagonist through academia-industry-government collaboration

Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by inflammation in multiple organs. A few treatments for SLE currently exist, including antimalarials, glucocorticoids, immunosuppressants, and two recently approved antibody agents; however, an unmet medical need remains for SLE. In addition, developing new drugs targeting SLE is a challenge since no specific biomarkers exist for the prediction of disease progression or drug response. A new drug candidate, E6742, is a specific antagonist of the toll-like receptors 7/8. To address the challenges for drug development in SLE, the process of developing E6742 utilizes a unique system of the Japan Agency for Medical Research and Development (AMED), the Cyclic Innovation for Clinical Empowerment (CiCLE) program. In the CiCLE program, a Phase 1 study in healthy adults was completed (NCT04683185) and a Phase 1/2 study in patients with SLE is on-going (NCT05278663). One of the potential benefits of this program is to conduct academia-led clinical research to identify specific biomarkers for E6742 in parallel with clinical studies (UMIN000042037). The aim of this review is to present current progress within the strategic collaboration of the AMED CiCLE program that optimize clinical development for patients with SLE.

Management of the sensitized pediatric renal transplant candidate

Kidney transplantation is the treatment of choice for patients with ESRD as it is associated with improved patient survival and better quality of life, especially in children. There are several barriers to a successful transplant including organ shortage, anatomic barriers, and immunologic barriers. One of the biggest immunologic barriers that precludes transplantation is sensitization, when patients have antibodies prior to transplantation, resulting in positive crossmatches with donor. 30%-40% of adult patients on the wait list are sensitized. There is a growing number of pediatric patients on the wait list who are sensitized. This poses a unique challenge to the pediatric transplant community. Therefore, attempts to perform desensitization to remove or suppress pathogenic HLA antibodies resulting in acceptable crossmatches, and ultimately a successful transplant, while reducing the risk of acute rejection, are much needed in these children. This review article aims to address the management of such patients both prior to transplantation, with strategies to overcome sensitization, and after transplantation with monitoring for allograft rejection and other complications.

CD19 CAR T-Cell Therapy in Autoimmune Disease - A Case Series with Follow-up

BACKGROUND

Treatment for autoimmune diseases such as systemic lupus erythematosus (SLE), idiopathic inflammatory myositis, and systemic sclerosis often involves long-term immune suppression. Resetting aberrant autoimmunity in these diseases through deep depletion of B cells is a potential strategy for achieving sustained drug-free remission.

METHODS

We evaluated 15 patients with severe SLE (8 patients), idiopathic inflammatory myositis (3 patients), or systemic sclerosis (4 patients) who received a single infusion of CD19 chimeric antigen receptor (CAR) T cells after preconditioning with fludarabine and cyclophosphamide. Efficacy up to 2 years after CAR T-cell infusion was assessed by means of Definition of Remission in SLE (DORIS) remission criteria, American College of Rheumatology-European League against Rheumatism (ACR-EULAR) major clinical response, and the score on the European Scleroderma Trials and Research Group (EUSTAR) activity index (with higher scores indicating greater disease activity), among others. Safety variables, including cytokine release syndrome and infections, were recorded.

RESULTS

The median follow-up was 15 months (range, 4 to 29). The mean (±SD) duration of B-cell aplasia was 112±47 days. All the patients with SLE had DORIS remission, all the patients with idiopathic inflammatory myositis had an ACR-EULAR major clinical response, and all the patients with systemic sclerosis had a decrease in the score on the EUSTAR activity index. Immunosuppressive therapy was completely stopped in all the patients. Grade 1 cytokine release syndrome occurred in 10 patients. One patient each had grade 2 cytokine release syndrome, grade 1 immune effector cell-associated neurotoxicity syndrome, and pneumonia that resulted in hospitalization.

CONCLUSIONS

In this case series, CD19 CAR T-cell transfer appeared to be feasible, safe, and efficacious in three different autoimmune diseases, providing rationale for further controlled clinical trials. (Funded by Deutsche Forschungsgemeinschaft and others.).

Longitudinal patterns and predictors of response to standard-of-care therapy in lupus nephritis: data from the Accelerating Medicines Partnership Lupus Network

BACKGROUND

Leveraging the Accelerating Medicines Partnership (AMP) Lupus Nephritis (LN) dataset, we evaluated longitudinal patterns, rates, and predictors of response to standard-of-care therapy in patients with lupus nephritis.

METHODS

Patients from US academic medical centers with class III, IV, and/or V LN and a baseline urine protein/creatinine (UPCR) ratio ≥ 1.0 (n = 180) were eligible for this analysis. Complete response (CR) required the following: (1) UPCR < 0.5; (2) normal serum creatinine (≤ 1.3 mg/dL) or, if abnormal, ≤ 125% of baseline; and (3) prednisone ≤ 10 mg/day. Partial response (PR) required the following: (1) > 50% reduction in UPCR; (2) normal serum creatinine or, if abnormal, ≤ 125% of baseline; and (3) prednisone dose ≤ 15 mg/day.

RESULTS

Response rates to the standard of care at week 52 were CR = 22.2%; PR = 21.7%; non-responder (NR) = 41.7%, and not determined (ND) = 14.4%. Only 8/180 (4.4%) patients had a week 12 CR sustained through week 52. Eighteen (10%) patients attained a week 12 PR or CR and sustained their responses through week 52 and 47 (26.1%) patients achieved sustained PR or CR at weeks 26 and 52. Week 52 CR or PR attainment was associated with baseline UPCR > 3 (ORadj = 3.71 [95%CI = 1.34-10.24]; p = 0.012), > 25% decrease in UPCR from baseline to week 12 (ORadj = 2.61 [95%CI = 1.07-6.41]; p = 0.036), lower chronicity index (ORadj = 1.33 per unit decrease [95%CI = 1.10-1.62]; p = 0.003), and positive anti-dsDNA antibody (ORadj = 2.61 [95%CI = 0.93-7.33]; p = 0.069).

CONCLUSIONS

CR and PR rates at week 52 were consistent with the standard-of-care response rates observed in prospective registrational LN trials. Low sustained response rates underscore the need for more efficacious therapies and highlight how critically important it is to understand the molecular pathways associated with response and non-response.

Engineered immune cells as therapeutics for autoimmune diseases

Current treatment options for autoimmune disease (AID) are essentially immunosuppressive, inhibiting the inflammatory cascade, without curing the disease. Therapeutic monoclonal antibodies (mAbs) that target B cells showed efficacy, emphasizing the importance of B lymphocytes in autoimmune pathogenesis. Treatments that eliminate more potently B cells would open a new therapeutic era for AID. Immune cells can now be bioengineered to express constructs that enable them to specifically eradicate pathogenic B lymphocytes. Engineered immune cells (EICs) have shown therapeutic promise in both experimental models and in clinical trials in AID. Next-generation platforms are under development to optimize their specificity and improve safety. The profound and durable B cell depletion achieved reinforces the view that this biotherapeutic option holds promise for treating AID.

CAR-T cells for treating systemic lupus erythematosus: A promising emerging therapy

Chimeric Antigen Receptor T-cell therapy (CAR-T), currently employed routinely for treating B-cell malignancies, has emerged as a groundbreaking approach in addressing severe autoimmune diseases, especially for systemic lupus erythematosus (SLE). The immunological rationale for targeting B lymphocytes in autoimmune diseases is well-established, demonstrating success in numerous autoantibody-mediated autoimmune conditions through targeted therapies over several years. However, this approach has often proven ineffective in the context of systemic lupus erythematosus. Recent data on CAR-T usage in lupus, revealed promising results including rapid and prolonged remission without treatment, highlighting the potential of CAR-T therapy in severe lupus cases. This article provides a comprehensive overview of CAR-T cells, tracing their evolution from hematological malignancies to their recent applications in autoimmune disorder, especially in lupus. Clinical trials within a regulated framework are now imperative to assess the procedural aspects in order to validate the considerable promise of CAR-T cell therapy in the field of autoimmune diseases. This includes evaluating safety and long-term efficacy and security of the procedure, the benefit-risk ratio in the field of autoimmunity, the availability and cost-related issues associated with this emerging cellular therapy procedure.

Kidney Outcomes and Preservation of Kidney Function With Obinutuzumab in Patients With Lupus Nephritis: A Post Hoc Analysis of the NOBILITY Trial

OBJECTIVE

To determine whether adding obinutuzumab to standard-of-care lupus nephritis (LN) therapy could improve the likelihood of long-term preservation of kidney function and do so with less glucocorticoids.

METHODS

Post hoc analyses of the phase II NOBILITY trial were performed. Time to unfavorable kidney outcome (a composite of treatment failure, doubling of serum creatinine, or death), LN flare, first 30% and 40% declines in estimated glomerular filtration rate (eGFR) from baseline, and chronic eGFR slope during the trial were compared between patients with active LN who were randomized to take obinutuzumab (n = 63) or placebo (n = 62) in combination with mycophenolate mofetil and glucocorticoids. The number of patients who achieved complete renal response (CRR) on 7.5 mg or less per day of prednisone was also determined.

RESULTS

Obinutuzumab reduced the risk of developing the composite kidney outcome by 60%, LN flare by 57%, and first eGFR decline of 30% or 40% by 80% and 91%, respectively. Patients receiving obinutuzumab had a significantly slower decline in eGFR than patients receiving placebo, with an annualized eGFR slope advantage of 4.1 ml/min/1.73 m2 /year (95% confidence interval 0.14-8.08). Overall, 38% of patients receiving obinutuzumab compared with 16% of patients receiving placebo achieved CRR at week 76 while receiving 7.5 mg or less per day of prednisone (P < 0.01); at week 104, the difference did not achieve significance (38% vs 22%; P = 0.06).

CONCLUSION

Post hoc analyses of NOBILITY demonstrated that compared with standard-of-care therapy, obinutuzumab treatment resulted in superior preservation of kidney function and prevention of LN flares. More patients achieved CRR at week 76 with less glucocorticoid use in the obinutuzumab group.

Population-wide long-term study of incidence, renal failure, and mortality rates for lupus nephritis

OBJECTIVE

Given limited regional data, we investigate the state-wide epidemiology, renal and patient outcomes for lupus nephritis (LN) in Western Australia (WA).

METHODS

Patients hospitalized with incident SLE (≥2 diagnostic codes in the state-wide WA Health Hospital Morbidity Data Collection) in the period 1985-2015 were included (n = 1480). LN was defined by the presence of glomerulonephritis and/or raised serum creatinine. Trends over three study decades for annual incidence rate (AIR)/100.000 population, mortality (MR), and end-stage renal disease (ESRD) rates/100 person years were analyzed by least square regression and compared with a matched control group (n = 12 840).

RESULTS

Clinical evidence of LN developed in 366 SLE patients (25.9%) after a median disease duration of 10 months (IQR 0-101) with renal biopsy performed in 308 (84.2%). The AIR for LN (0.63/100.000) did not change significantly over time (R2  = .11, p = .85), while point prevalence reached 11.9/100.000 in 2015. ESRD developed in 14.1% (n = 54) of LN patients vs. 0.2% in non-LN SLE patients and 0.05% in controls (all p ≤ 0.01). ESRD rates increased over time in LN patients (0.4 to 0.7, R2 = .52, p = .26). The odds ratio for death was 8.81 (CI 3.78-22.9) for LN and 6.62 (CI 2.76-17.9) for non-LN SLE patients compared to controls and MR for LN patients increased over time (1.3 to 2.2, R2 = .84, p = .26).

CONCLUSIONS

The incidence rate of LN in WA remained unchanged over 30 years. A lack of improvement in renal failure and mortality rates illustrates the pressing need for better long-term treatment options and/or strategies in LN.

Targeted therapies for lupus nephritis: Current perspectives and future directions

ABSTRACT

Lupus nephritis (LN), a severe manifestation of systemic lupus erythematosus, poses a substantial risk of progression to end-stage renal disease, with increased mortality. Conventional therapy for LN relies on broad-spectrum immunosuppressants such as glucocorticoids, mycophenolate mofetil, and calcineurin inhibitors. Although therapeutic regimens have evolved over the years, they have inherent limitations, including non-specific targeting, substantial adverse effects, high relapse rates, and prolonged maintenance and remission courses. These drawbacks underscore the need for targeted therapeutic strategies for LN. Recent advancements in our understanding of LN pathogenesis have led to the identification of novel therapeutic targets and the emergence of biological agents and small-molecule inhibitors with improved specificity and reduced toxicity. This review provides an overview of the current evidence on targeted therapies for LN, elucidates the biological mechanisms of responses and failure, highlights the challenges ahead, and outlines strategies for subsequent clinical trials and integrated immunomodulatory approaches.

Kidney involvement in systemic lupus erythematosus: From the patient assessment to a tailored treatment

In the last few years, several studies have provided new evidence for the diagnosis, management, and follow-up of patients with lupus nephritis. Evidence showing dissociation between clinical and histological findings has prompted reevaluation of the role of the kidney biopsy as a tool for diagnosis and follow-up. In therapeutics, four immunosuppressive schemes now have supporting evidence for use as initial therapy. Current challenges include individualized selection of the best immunosuppressive regimen, an unmet need for non-invasive biomarkers of disease activity to inform treatment responses and guide subsequent therapy, holistic patient management in this complex, multisystem disease, and ultimately the development of more targeted therapies directed at specific effector pathways driving glomerular inflammation and damage in order to improve treatment response. In this communication, we review the diagnostic and therapeutic approach to lupus nephritis, as well as evaluation of response to therapy and disease control.

Cytokine and reactivity profiles in SLE patients following anti-CD19 CART therapy

Chimeric antigen receptor (CAR) T cells targeting CD19+ B cells have demonstrated efficacy in refractory systemic lupus erythematosus (SLE). Although initial clinical data suggest that anti-CD19 CAR T cell therapy is well tolerated and highly effective, the immunologic consequences of CAR T cell therapy in SLE patients remain unclear. We profiled serum in six refractory SLE patients prior to and 3 months following CAR T cell infusion. Three months post T cell infusion, the inflammatory cytokines IL-6 and TNFα decreased in patient sera. This was accompanied by elevations in serum IL-7 and BAFF. Furthermore, SLE-associated antibodies dropped profoundly in five of six patients. Last, consistent with other reports of CD19 CAR T therapy in B cell malignancies, we were able to show marginal impact of anti-CD19 CART therapy on pre-existing humoral immune responses in SLE patients. Together, these results provide insights into the mechanisms of efficacy of anti-CD19 CAR T cell therapy in SLE.

Canadian patient experiences of lupus nephritis: a qualitative analysis

OBJECTIVE

Lupus nephritis (LN) is one of the most severe manifestations of SLE; however, we know little about the lived experience of LN. This research investigates patient experiences and perspectives of (1) LN diagnosis; (2) living with LN; and (3) LN healthcare and treatment.

METHODS

Patients aged ≥18 years with biopsy-proven pure or mixed International Society of Nephrology/Renal Pathology Society class III, IV or V LN were purposefully recruited from a Canadian lupus cohort to participate in semistructured in-depth interviews.

RESULTS

Thirty patients with LN completed the interviews. The mean (SD) age was 42.1 (16.4) years, and 86.7% were female. Participants described challenges seeking, receiving and adjusting to a LN diagnosis, and some reported that their diagnosis process took weeks to years. While 16 participants were provided resources by healthcare providers to help them through the process of diagnosis, the need for accessible LN-specific information at diagnosis was highlighted (n=18). Participants also described the unpredictability of living with LN, particularly related to impacts on physical and mental health, relationships, leisure activities, employment and education, and family planning. While most (n=26) participants reported a positive impression of their care, the side effects of LN medications and the need to increase patient and societal awareness/understanding of LN were highlighted in the context of healthcare and treatment.

CONCLUSIONS

The unpredictability of living with LN, the heavy treatment burden and a lack of patient/societal awareness substantially affect the lived experience of LN. These findings will inform the development of LN-specific patient resources to increase understanding of LN and improve well-being for patients.

B cell-intrinsic Myd88 regulates disease progression in murine lupus

Nucleic acid-specific Toll-like receptors (TLRs) have been implicated in promoting disease pathogenesis in systemic lupus erythematosus (SLE). Whether such TLRs mediate disease onset, progression, or both remains undefined; yet the answer to this question has important therapeutic implications. MyD88 is an essential adaptor that acts downstream of IL-1 family receptors and most TLRs. Both global and B cell-specific Myd88 deficiency ameliorated disease in lupus-prone mice when constitutively deleted. To address whether Myd88 was needed to sustain ongoing disease, we induced B cell-specific deletion of Myd88 after disease onset in MRL.Faslpr mice using an inducible Cre recombinase. B cell-specific deletion of Myd88 starting after disease onset resulted in ameliorated glomerulonephritis and interstitial inflammation. Additionally, treated mice had reduced autoantibody formation and an altered B cell compartment with reduced ABC and plasmablast numbers. These experiments demonstrate the role of MyD88 in B cells to sustain disease in murine lupus. Therefore, targeting MyD88 or its upstream activators may be a viable therapeutic option in SLE.

Obinutuzumab in Frequently Relapsing and Steroid-Dependent Nephrotic Syndrome in Children

BACKGROUND

B-cell depletion with rituximab induces sustained remission in children with steroid-dependent or frequently relapsing nephrotic syndrome. However, most patients relapse after B-cell recovery, and some patients do not achieve B-cell depletion. Obinutuzumab is a second-generation anti-CD20 antibody designed to overcome such situations in B-cell malignancies and was recently reported to be safe and effective in other autoimmune diseases affecting the kidneys.

METHODS

We retrospectively report 41 children with steroid-dependent or frequently relapsing nephrotic syndrome treated with a single low-dose infusion of obinutuzumab at Robert-Debre Hospital between April 2018 and December 2020. Participants were treated because of rituximab resistance or relapse after rituximab and received a single infusion of 300 mg/1.73 m 2 obinutuzumab with cessation of oral immunosuppressors within 2 months.

RESULTS

B-cell depletion was achieved in all participants and lasted a median of 8.3 months (interquartile range, 6.4-11.1), a duration exceeding that for last rituximab treatment. At 12 and 24 months, 92% (38/41) and 68% (28/41) of patients, respectively, were in sustained remission. Mild infusion reactions occurred in five participants (12%) and neutropenia in nine (21%). No significant decrease in IgG level was reported during treatment, and whereas IgM levels decreased in 34 patients (83%), they were normal at last follow-up in 32 (78%).

CONCLUSIONS

These results identified low-dose obinituzumab as a promising treatment option in children with steroid-dependent or frequently relapsing nephrotic syndrome, including those resistant to rituximab. The tolerance profile of obinutuzumab was similar to that of rituximab, but hemogram and immunoglobulin levels should be monitored.

Long-term outcomes with rituximab as add-on therapy in severe childhood-onset lupus nephritis

BACKGROUND

Long-term data pertaining to rituximab as add-on therapy in childhood-onset lupus nephritis (cLN) is scarce.

METHODS

A retrospective cohort study was conducted on all patients with proliferative cLN, diagnosed ≤ 18 years and between 2005 and 2021, who received rituximab for LN episodes that were life/organ threatening and/or treatment resistant to standard immunosuppression.

RESULTS

Fourteen patients with cLN (female, n = 10) were included, with median follow-up period of 6.9 years. LN episodes (class III, n = 1; class IV, n = 11; class IV + V, n = 2) requiring rituximab occurred at 15.6 years (IQR 12.8-17.3), urine protein:creatinine ratio was 8.2 mg/mg (IQR 3.4-10.1) and eGFR was 28 mL/min/1.73 m2 (IQR 24-69) prior to rituximab treatment. Ten and four patients received rituximab at 1500 mg/m2 and 750 mg/m2, which were given at 46.5 days (IQR 19-69) after commencement of standard therapies. Treatment with rituximab resulted in improvements in proteinuria (ps < 0.001), eGFR (ps < 0.01) and serological parameters, including haemoglobin levels, complement 3 levels and anti-dsDNA antibodies, compared with baseline. Rates of complete/partial remission at 6-, 12- and 24-month post-rituximab were 28.6/42.8%, 64.2/21.4% and 69.2/15.3%. All three patients who required acute kidney replacement therapy became dialysis-free after rituximab. Relapse rate following rituximab was 0.11 episodes/patient-year. There was no lethal complication or severe infusion reaction. Hypogammaglobulinaemia was the most frequent complication (45%) but was mostly asymptomatic. Neutropenia and infections were observed in 20% and 25% of treatments. Upon last follow-up, three (21%) and two (14%) patients developed chronic kidney disease (stage 2, n = 2; stage 4; n = 1) and kidney failure, respectively.

CONCLUSION

Add-on rituximab is an effective and safe rescue therapy for cLN patients with life-/organ-threatening manifestations or treatment-resistance. A higher resolution version of the Graphical abstract is available as Supplementary information.

Treatment of systemic lupus erythematosus: new therapeutic options

Systemic lupus erythematosus (SLE) is a systemic autoimmune inflammatory disease of unknown cause, with heterogeneity in its clinical presentation, as well as variability in its clinical course and prognosis. The current goal of treatment is to achieve disease remission or a state of low activity, and thereby improve the patient's quality of life. Biological therapy in lupus, unlike other entities, although it has not been fully established, in recent years it has burst onto the scene with important therapeutic novelties. This review aims to update the therapeutic tools for the treatment of SLE focusing on the new molecules that have achieved the objectives of their clinical trials.

Clinical advances in immunotherapy for immune-mediated glomerular diseases

BACKGROUND AND OBJECTIVE

Due to the suboptimal therapeutic efficacy and potential adverse effects associated with traditional immunosuppressive medications, there has been an increasing emphasis on the development and utilization of immunotherapies. This paper aims to provide clinicians with valuable insights for selecting appropriate therapeutic approaches and contribute to the development of novel immunotherapeutic drugs.

MAIN BODY

This paper categorizes the immunotherapeutic drugs that are used for the treatment of immune-mediated glomerular diseases into three groups: immunotherapies targeting antigen-presenting cells (anti-CD80), immunotherapies targeting T/B cells (anti-CD20, anti-CD22, BAFF and APRIL inhibitors, CD40-CD40L inhibitors, proteasome inhibitors, Syk inhibitors, and Btk inhibitors), and immunotherapies targeting the complement system (C5 inhibitors, C5a/C5aR inhibitors, C3 inhibitors, MASP2 inhibitors, factor B inhibitors, and factor D inhibitors). The article then provides a comprehensive overview of advances related to these immunotherapeutic drugs in clinical research.

CONCLUSION

Certain immunotherapeutic drugs, such as rituximab, belimumab, and eculizumab, have exhibited notable efficacy in treating specific immune-mediated glomerular diseases, thereby providing novel therapeutic approaches for patients. Nonetheless, the efficacy of numerous immunotherapeutic drugs remains to be substantiated.

Clinical research progress of novel biologics for the treatment of lupus nephritis

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the loss of immune tolerance. Lupus nephritis (LN) is one of the most common manifestations of severe organ damage in SLE, and also an important cause of disability and death. Its pathogenesis is associated with immune abnormalities such as immune cells, cytokines, and immune complex deposition. Traditional immunosuppressive therapy has been unable to meet the treatment needs of patients while bringing them toxic effects. In recent years, targeted therapies have emerged, and several novel biologics have gradually entered people's sight. This review will briefly introduce the pathogenesis of LN and the mechanism of biological targets, and summarize and analyze the clinical trials of new biologics for treating LN. Although not all biologics show positive results in clinical trials, the experience learned from these trials can help researchers adjust and plan future trial programs to seek better treatment methods.

CAR T-cell therapy in autoimmune diseases

Despite the tremendous progress in the clinical management of autoimmune diseases, many patients do not respond to the currently used treatments. Autoreactive B cells play a key role in the pathogenesis of autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis. B-cell-depleting monoclonal antibodies, such as rituximab, have poor therapeutic efficacy in autoimmune diseases, mainly due to the persistence of autoreactive B cells in lymphatic organs and inflamed tissues. The adoptive transfer of T cells engineered to target tumour cells via chimeric antigen receptors (CARs) has emerged as an effective treatment modality in B-cell malignancies. In the last 2 years treatment with autologous CAR T cells directed against the CD19 antigen has been introduced in therapy of autoimmune disease. CD19 CAR T cells induced a rapid and sustained depletion of circulating B cells, as well as in a complete clinical and serological remission of refractory systemic lupus erythematosus and dermatomyositis. In this paper, we discuss the evolving strategies for targeting autoreactive B cells via CAR T cells, which might be used for targeted therapy in autoimmune diseases.

Single cell spatial transcriptomic profiling of childhood-onset lupus nephritis reveals complex interactions between kidney stroma and infiltrating immune cells

Children with systemic lupus erythematosus (SLE) are at increased risk of developing kidney disease, termed childhood-onset lupus nephritis (cLN). Single cell transcriptomics of dissociated kidney tissue has advanced our understanding of LN pathogenesis, but loss of spatial resolution prevents interrogation of in situ cellular interactions. Using a technical advance in spatial transcriptomics, we generated a spatially resolved, single cell resolution atlas of kidney tissue (>400,000 cells) from eight cLN patients and two controls. Annotated cells were assigned to 35 reference cell types, including major kidney subsets and infiltrating immune cells. Analysis of spatial distribution demonstrated that individual immune lineages localize to specific regions in cLN kidneys, including myeloid cells trafficking to inflamed glomeruli and B cells clustering within tubulointerstitial immune hotspots. Notably, gene expression varied as a function of tissue location, demonstrating how incorporation of spatial data can provide new insights into the immunopathogenesis of SLE. Alterations in immune phenotypes were accompanied by parallel changes in gene expression by resident kidney stromal cells. However, there was little correlation between histologic scoring of cLN disease activity and glomerular cell transcriptional signatures at the level of individual glomeruli. Finally, we identified modules of spatially-correlated gene expression with predicted roles in induction of inflammation and the development of tubulointerstitial fibrosis. In summary, single cell spatial transcriptomics allows unprecedented insights into the molecular heterogeneity of cLN, paving the way towards more targeted and personalized treatment approaches.

The plethora of immunomodulatory drugs: opportunities for immune-mediated kidney diseases

In recent decades, insights into the molecular pathways involved in disease have revolutionized the treatment of autoimmune diseases. A plethora of targeted therapies have been identified and are at varying stages of clinical development in renal autoimmunity. Some of these agents, such as rituximab or avacopan, have been approved for the treatment of immune-mediated kidney disease, but kidney disease lags behind more common autoimmune disorders in new drug development. Evidence is accumulating as to the importance of adaptive immunity, including abnormalities in T-cell activation and signaling, and aberrant B-cell function. Furthermore, innate immunity, particularly the complement and myeloid systems, as well as pathologic responses in tissue repair and fibrosis, play a key role in disease. Collectively, these mechanistic studies in innate and adaptive immunity have provided new insights into mechanisms of glomerular injury in immune-mediated kidney diseases. In addition, inflammatory pathways common to several autoimmune conditions exist, suggesting that the repurposing of some existing drugs for the treatment of immune-mediated kidney diseases is a logical strategy. This new understanding challenges the clinical investigator to translate new knowledge into novel therapies leading to better disease outcomes. This review highlights promising immunomodulatory therapies tested for immune-mediated kidney diseases as a primary indication, details current clinical trials and discusses pathways that could be targeted in the future.

Efficacy and safety of novel biologics in the treatment of lupus nephritis based on registered clinical trials: a systematic review and network meta-analysis

To compare the clinical effectiveness and safety of novel biologics for the treatment of lupus nephritis based on a reticulated meta-analysis approach. Registered clinical trials in 4 major databases (PubMed, Embase, Web of Science, The Cochrane Register of Clinical Trials) and ClinicalTrials.gov were systematically searched with a search time frame of build to June 2022. And we screened registered randomized controlled clinical trials of biologics for the treatment of lupus nephritis according to the protocol's nadir criteria. Trials were evaluated for quality using the Cochrane Risk of Bias Assessment Tool, and data were statistically analyzed using Stata 16.0 and Review Manager 5.3 software to compare and rank differences in effectiveness and safety between the biologics. A total of 10 registered randomized controlled clinical trials involving 2148 subjects were included in this study. The interventions were ranked from best to worst in terms of the primary outcome indicator of effectiveness, renal complete remission: belimumab > anifrolumab (900 + 300) mg > obinutuzumab > ocrelizumab 400 mg > abatacept 30/10 mg/kg > belimumab + rituximab > abatacept 10/10 mg/kg > abatacept (30/10 + 10/10) mg/kg > placeo > ocrelizumab 1000 mg > rituximab > anifrolumab 300 mg, belimumab was superior to placebo [OR = 1.75, 95% CI (1.13, 2.70)] and anifrolumab 300 mg [OR = 3.27, 95% CI (1.05, 10.14)], anifrolumab (900 + 300) mg was superior to anifrolumab 300 mg [OR = 3.56, 95% CI (1.30, 9.76)], and all were statistically significant. The ranking of each intervention in terms of overall renal remission for secondary outcome indicators from best to worst was: obinutuzumab > belimumab + rituximab > anifrolumab (900 + 300) mg > ocrelizumab 1000 mg > ocrelizumab 400 mg > belimumab > rituximab 1000 mg > abatacept 30/10 mg/kg > abatacept (30/10 + 10/10) mg/kg > placeo > abatacept 10/10 mg/kg > anifrolumab 300 mg, obinutuzumab was superior to placebo [OR = 2.27, 95% CI (1.11, 4.67)] and belimumab was also superior to placebo [OR = 1.56, 95% CI (1.07, 2.27)], and all were statistically significant. In terms of safety, with a focus on serious adverse events and serious infections, the results were: Serious adverse events at 1 year of monitoring occurred better with ocrelizumab 1000 mg than ocrelizumab 400 mg [OR = 0.51, 95% CI (0.29, 0.89)] and were statistically different; serious adverse events at 2 years of monitoring infection adverse events occurred better with obinutuzumab than with abatacept (30/10 + 10/10) mg/kg [OR = 0.24, 95% CI (0.07, 0.81)] and were statistically different. The safety of the new biologics in combination with conventional standard therapies is generally good, but it is belimumab and obinutuzumab that are most effective in achieving complete and overall remission in the kidney. This study protocol has been registered with PROSPERO, with a registration number of CRD42021262498.

Biomarkers Associated with Drugs for the Treatment of Lupus Nephritis

The constant updating of lupus drug treatment guidelines has led to a question. How can the efficacy of treatment be more effectively monitored? Systemic lupus erythematosus (SLE) is a complex autoimmune disease that often presents clinically with multi-organ involvement, and approximately 30% of patients with SLE develop lupus nephritis (LN). Therefore, it is important to better track disease progression and drug efficacy. Now, kidney biopsy is still the gold standard for diagnosing and guiding the treatment of LN, but it is invasive and expensive. If simple, non-invasive and effective biomarkers can be found, drug intervention and prognosis can be better monitored and targeted. In this review, we focus on LN and explore biomarkers related to LN therapeutics, providing clinicians with more possibilities to track the therapeutic effect of drugs, improve treatment options and assess patient outcomes.

Advances in the management of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a severe multisystem autoimmune disease that can cause injury in almost every body system. While considered a classic example of autoimmunity, it is still relatively poorly understood. Treatment with immunosuppressive agents is challenging, as many agents are relatively non-specific, and the underlying disease is characterized by unpredictable flares and remissions. This State of The Art Review provides a comprehensive current summary of systemic lupus erythematosus based on recent literature. In basic and translational science, this summary includes the current state of genetics, epigenetics, differences by ancestry, and updates about the molecular and immunological pathogenesis of systemic lupus erythematosus. In clinical science, the summary includes updates in diagnosis and classification, clinical features and subphenotypes, and current guidelines and strategies for treatment. The paper also provides a comprehensive review of the large number of recent clinical trials in systemic lupus erythematosus. Current knowns and unknowns are presented, and potential directions for the future are suggested. Improved knowledge of immunological pathogenesis and the molecular differences that exist between patients should help to personalize treatment, minimize side effects, and achieve better outcomes in this difficult disease.

Lupus Nephritis in Children: Novel Perspectives

Childhood-onset systemic lupus erythematosus is an inflammatory and autoimmune condition characterized by heterogeneous multisystem involvement and a chronic course with unpredictable flares. Kidney involvement, commonly called lupus nephritis, mainly presents with immune complex-mediated glomerulonephritis and is more frequent and severe in adults. Despite a considerable improvement in long-term renal prognosis, children and adolescents with lupus nephritis still experience significant morbidity and mortality. Moreover, current literature often lacks pediatric-specific data, leading clinicians to rely exclusively on adult therapeutic approaches. This review aims to describe pediatric lupus nephritis and provide an overview of the novel perspectives on the pathogenetic mechanisms, histopathological classification, therapeutic approach, novel biomarkers, and follow-up targets in children and adolescents with lupus nephritis.

Management of Lupus Nephritis: New Treatments and Updated Guidelines

Management of lupus nephritis has evolved considerably over the past years. Here, we provide a comprehensive review of clinical trials that form the basis for the Kidney Disease: Improving Global Outcomes and EULAR/ERA-EDTA updated guidelines and present day trials that will change the landscape of lupus nephritis therapy in years to come. In addition, we highlight the issues related to cost of therapy, resistant disease, and downstream adverse effects of specific therapies.