Efficacy and safety of rituximab in patients with active proliferative lupus nephritis: the Lupus Nephritis Assessment with Rituximab study

Management of lupus nephritis: a systematic literature review informing the 2019 update of the joint EULAR and European Renal Association-European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations

Objectives

To analyse the current evidence for the management of lupus nephritis (LN) informing the 2019 update of the EULAR/European Renal Association-European Dialysis and Transplant Association recommendations.

Methods

According to the EULAR standardised operating procedures, a PubMed systematic literature review was performed, from January 1, 2012 to December 31, 2018. Since this was an update of the 2012 recommendations, the final level of evidence (LoE) and grading of recommendations considered the total body of evidence, including literature prior to 2012.

Results

We identified 387 relevant articles. High-quality randomised evidence supports the use of immunosuppressive treatment for class III and class IV LN (LoE 1a), and moderate-level evidence supports the use of immunosuppressive treatment for pure class V LN with nephrotic-range proteinuria (LoE 2b). Treatment should aim for at least 25% reduction in proteinuria at 3 months, 50% at 6 months and complete renal response (<500–700 mg/day) at 12 months (LoE 2a-2b). High-quality evidence supports the use of mycophenolate mofetil/mycophenolic acid (MMF/MPA) or low-dose intravenous cyclophosphamide (CY) as initial treatment of active class III/IV LN (LoE 1a). Combination of tacrolimus with MMF/MPA and high-dose CY are alternatives in specific circumstances (LoE 1a). There is low-quality level evidence to guide optimal duration of immunosuppression in LN (LoE 3). In end-stage kidney disease, all methods of kidney replacement treatment can be used, with transplantation having the most favourable outcomes (LoE 2b).

Conclusions

There is high-quality evidence to guide the initial and subsequent phases of class III/IV LN treatment, but low-to-moderate quality evidence to guide treatment of class V LN, monitoring and optimal duration of immunosuppression.

Rituximab-associated hypogammaglobulinemia in autoimmune rheumatic diseases: a single-center retrospective cohort study

B-cell targeted therapies, such as rituximab (RTX), are used widely in autoimmune rheumatic diseases (AIRD). RTX can cause hypogammaglobulinemia and predispose patients to infections. Herein, we asked whether the underlying diagnosis influences the risk for hypogammaglobulinemia in patients treated with RTX. All patients who received RTX infusions and carried a diagnosis of rheumatoid arthritis (RA), ANCA-associated vasculitis (AAV), or connective tissue disease (CTD) were included in this single-center retrospective cohort study. We used STATA® for analysis: Chi-square test was used for comparing categorical variables. Based on distribution, continuous variables were compared using the t test/ANOVA or the Wilcoxon/Kruskal-Wallis tests. Of the 163 patients who received RTX for an AIRD, 60 with pre- and post- RTX immunoglobulins were analyzed. A higher incidence of post-treatment hypogammaglobulinemia was seen in AAV (45%) compared to RA (22%) and CTD (9.1%) groups (p = 0.03). Glucocorticoid exposure of 10 mg or more was identified as a significant risk factor for hypogammaglobulinemia. Finally, we observed a higher number of clinically significant infections per person in the AAV group than in the RA and CTD groups. We observed an increased incidence of hypogammaglobulinemia in the RTX-treated AAV group, with almost half of patients developing post-RTX hypogammaglobulinemia. The rate of infections per person was highest in the AAV group. Screening immunoglobulins were not consistently measured pre- and post-RTX. Results highlight a need for increased awareness of the role of immunoglobulin measurement before maintenance doses of RTX, especially in patients with AAV and steroid exposure.

B cells as target for immunotherapy in rheumatic diseases - current status

This mini-review is a short overview of different therapeutical strategies targeting B cells in systemic autoimmune rheumatic diseases, mainly: rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and primary Sjogren Syndrome (pSS). Many strategies and their rationale are discussed in this review: B cells' depletion (anti-CD20, anti-CD22), long-lived plasma cells depletion (anti-CD19, anti-CD27, anti-CD38 and anti-CD138), changing activation of B cells (anti-BAFF) and inhibiting proteasomes in plasma cells (bortezomib). The past successful therapies and less successful are shown, and the possible reasons for failures are discussed.

Efficacy and safety of voclosporin versus placebo for lupus nephritis (AURORA 1): a double-blind, randomised, multicentre, placebo-controlled, phase 3 trial

BACKGROUND

Voclosporin, a novel calcineurin inhibitor approved for the treatment of adults with lupus nephritis, improved complete renal response rates in patients with lupus nephritis in a phase 2 trial. This study aimed to evaluate the efficacy and safety of voclosporin for the treatment of lupus nephritis.

METHODS

This multicentre, double-blind, randomised phase 3 trial was done in 142 hospitals and clinics across 27 countries. Patients with a diagnosis of systemic lupus erythematosus with lupus nephritis according to the American College of Rheumatology criteria, and a kidney biopsy within 2 years that showed class III, IV, or V (alone or in combination with class III or IV) were eligible. Patients were randomly assigned (1:1) to oral voclosporin (23·7 mg twice daily) or placebo, on a background of mycophenolate mofetil (1 g twice daily) and rapidly tapered low-dose oral steroids, by use of an interactive web response system. The primary endpoint was complete renal response at 52 weeks defined as a composite of urine protein creatinine ratio of 0·5 mg/mg or less, stable renal function (defined as estimated glomerular filtration rate [eGFR] ≥60 mL/min/1·73 m² or no confirmed decrease from baseline in eGFR of >20%), no administration of rescue medication, and no more than 10 mg prednisone equivalent per day for 3 or more consecutive days or for 7 or more days during weeks 44 through 52, just before the primary endpoint assessment. Safety was also assessed. Efficacy analysis was by intention-to-treat and safety analysis by randomised patients receiving at least one dose of study treatment. The trial is registered with ClinicalTrials.gov, NCT03021499.

FINDINGS

Between April 13, 2017, and Oct 10, 2019, 179 patients were assigned to the voclosporin group and 178 to the placebo group. The primary endpoint of complete renal response at week 52 was achieved in significantly more patients in the voclosporin group than in the placebo group (73 [41%] of 179 patients vs 40 [23%] of 178 patients; odds ratio 2·65; 95% CI 1·64-4·27; p<0·0001). The adverse event profile was balanced between the two groups; serious adverse events occurred in 37 (21%) of 178 in the voclosporin group and 38 (21%) of 178 patients in the placebo group. The most frequent serious adverse event involving infection was pneumonia, occurring in 7 (4%) patients in the voclosporin group and in 8 (4%) patients in the placebo group. A total of six patients died during the study or study follow-up period (one [<1%] patient in the voclosporin group and five [3%] patients in the placebo group). None of the events leading to death were considered by the investigators to be related to the study treatments.

INTERPRETATION

Voclosporin in combination with MMF and low-dose steroids led to a clinically and statistically superior complete renal response rate versus MMF and low-dose steroids alone, with a comparable safety profile. This finding is an important advancement in the treatment of patients with active lupus nephritis.

FUNDING

Aurinia Pharmaceuticals.

Current Status of the Evaluation and Management of Lupus Patients and Future Prospects

The vastly diverse nature of systemic lupus erythematosus (SLE) poses great challenges to clinicians and patients, as well as to research and drug development efforts. Precise management of lupus patients would be advanced by the ability to identify specific abnormalities operative in individual patients at the time of encounter with the clinician. Advances in new technologies and bioinformatics have greatly improved the understanding of the pathophysiology of SLE. Recent research has focused on the discovery and classification of sensitive and specific markers that could aid early accurate diagnosis, better monitoring of disease and identification of appropriate therapy choices based on specific dysregulated molecular pathways. Here, we summarize some of the advances and discuss the challenges in moving toward precise patient-centric management modalities in SLE.

Iguratimod: Novel Molecular Insights and a New csDMARD for Rheumatoid Arthritis, from Japan to the World

Iguratimod (IGU) is a conventional synthetic disease-modifying anti-rheumatic drug (csDMARD) routinely prescribed in Japan since 2012 to patients with rheumatoid arthritis (RA). Iguratimod acts directly on B cells by inhibiting the production of inflammatory cytokines (tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-8, IL-17), thereby suppressing the production of immunoglobulin and inhibiting the activity of nuclear factor kappa-light chain enhancer of activated B cells. In Japan, it is one of the most used csDMARDs in daily practice, but it is not recommended as a treatment for RA due to the lack of large-scale evidence established overseas. However, recent reports on the novel pharmacological effects of IGU on lymphocytes and synovial fibroblasts, as well as its efficacy in daily practice, have increased its importance as a drug for the treatment of RA. In this review, we highlighted the basic and clinical studies in IGU and discuss its potential as a new therapeutic agent for the treatment of RA.

Biologics in the treatment of Sjogren's syndrome, systemic lupus erythematosus, and lupus nephritis

PURPOSE OF REVIEW

It is an understatement to say that drug approvals in systemic lupus erythematosus (SLE), lupus nephritis, and Sjogren's syndrome have lagged far behind those in other autoimmune diseases, such as rheumatoid arthritis and psoriatic arthritis. Reasons for this are multiple and include the molecular and clinical heterogeneity of these conditions; confounding by background medications, especially corticosteroids; and clinical trial endpoints. However, the tides are changing, and there have been several bright spots in our attempts to bring more efficacious drugs to our patients.

RECENT FINDINGS

Several positive phase II and phase III trials in SLE and lupus nephritis with drugs such as anifrolumab, voclosporin, belimumab, and obinutuzumab will no doubt eventually generate regulatory approvals for most, if not all, of these drugs. Although early in development, the promising results in Sjogren's syndrome with iscalimab and ianalumab should make the Sjogren's syndrome community quite hopeful of future drug approvals.

SUMMARY

In this review, we highlight recent study results in Sjogren's syndrome, SLE, and lupus nephritis, emphasizing investigational therapies in late stage development, but we also provide a glimpse into drugs of the future.

Transcriptomic studies of systemic lupus erythematosus

The management of systemic lupus erythematosus (SLE) remains challenging for clinicians because of the clinical heterogeneity of this disease. In attempts to identify useful biomarkers for the diagnosis of and treatment strategies for SLE, previous microarray and RNA sequencing studies have demonstrated several disease-relevant signatures in SLE. Of these, the interferon (IFN) signature is complex, involving IFNβ- and IFNγ-response genes in addition to IFNα-response genes. Some studies revealed that myeloid lineage/neutrophil and plasma cell signatures as well as the IFN signature were correlated with disease activity, lupus nephritis, and complications of pregnancy, although some of these findings remain controversial. Cell-type-specific gene expression analysis revealed the importance of an exhaustion signature in CD8+ T cells for SLE outcome. Recent single-cell RNA sequencing analyses of SLE blood and tissues demonstrated molecular heterogeneity and identified several distinct subpopulations as key players in SLE pathogenesis. Further studies are required to identify novel treatment targets and determine precise patient stratification in SLE. In this review, we discuss the findings and limitations of SLE transcriptomic studies.

Lupus Pneumonitis Therapy Masks Coronavirus (COVID-19)

Introduction

Coronavirus pneumonitis can mimic, or present as, lupus pneumonitis. Lupus may cause inflammation of the myocardium. Lupus pneumonitis high-dose steroid therapy may mask coronavirus (COVID-19). Case Study. The patient is a 65 y/o Hispanic female with lupus pneumonitis complicated by COVID-19. Her diagnosis was confirmed by a renal biopsy. She had nephritic and nephrotic syndrome. She was hospitalized a month earlier with shortness of breath with pulmonary infiltrates and was treated with steroids. The symptoms resolved quickly with shrinking consolidations and infiltrates. The patient returned to the office for shortness of breath with a presumptive diagnosis of recurrent lupus pneumonitis from steroid taper. The patient had a CT scan of the chest that revealed upper lobe interstitial and peripheral infiltrates. The radiologist felt that this was suspicious for coronavirus pneumonitis, and the patient was placed in isolation and continued therapy for lupus pneumonitis. She deteriorated, became hypoxic, and ventilated.

Conclusion

All lupus pneumonitis patients, in fact all lupus patients in general (personal experience), on high-dose steroid therapy should be tested for COVID-19 to ensure proper diagnosis and therapy planning.

Advances in Lupus Nephritis Pathogenesis: From Bench to Bedside

Systemic lupus erythematosus (SLE) is the prototype of autoimmune disorders caused by a loss of tolerance to endogenous nuclear antigens triggering an aberrant autoimmune response targeting various tissues. Lupus nephritis (LN), a major cause of morbidity and mortality in patients with SLE, affects up to 60% of patients. The recent insights into the genetic and molecular basis of SLE and LN paved the way for newer therapies to be developed for these patients. Apart from the traditional B-cell-centered view of this disease pathogenesis, acknowledging that multiple extrarenal and intrarenal pathways contribute to kidney-specific autoimmunity and injury may help refine the individual therapeutic and prognostic characterization of such patients. Accordingly, the formerly induction-maintenance treatment strategy was recently challenged with the exciting results obtained from the trials that evaluated add-on therapy with voclosporin, belimumab, or Obinutuzumab. The scope of this review is to provide an insight into the current knowledge of LN pathogenesis and future therapeutic strategies.

The Type II Anti-CD20 Antibody Obinutuzumab (GA101) Is More Effective Than Rituximab at Depleting B Cells and Treating Disease in a Murine Lupus Model

OBJECTIVE

Depleting pathogenic B cells could treat systemic lupus erythematosus (SLE). However, depleting B cells in an inflammatory setting such as lupus is difficult. This study was undertaken to investigate whether a type II anti-CD20 monoclonal antibody (mAb) with a different mechanism of action, obinutuzumab (GA101), is more effective than a type I anti-CD20 mAb, rituximab (RTX), in B cell depletion in lupus, and whether efficient B cell depletion results in amelioration of disease.

METHODS

We treated lupus-prone MRL/lpr mice expressing human CD20 on B cells (hCD20 MRL/lpr mice) with either RTX or GA101 and measured B cell depletion under various conditions, as well as multiple clinical end points.

RESULTS

A single dose of GA101 was markedly more effective than RTX in depleting B cells in diseased MRL/lpr mice (P < 0.05). RTX overcame resistance to B cell depletion in diseased MRL/lpr mice with continuous treatments. GA101 was more effective in treating hCD20 MRL/lpr mice with early disease, as GA101-treated mice had reduced glomerulonephritis (P < 0.05), lower anti-RNA autoantibody titers (P < 0.05), and fewer activated CD4+ T cells (P < 0.0001) compared to RTX-treated mice. GA101 also treated advanced disease, and continual treatment prolonged survival. Using variants of GA101, we also elucidated B cell depletion mechanisms in vivo in mice with lupus.

CONCLUSION

Albeit both anti-CD20 antibodies ameliorated early disease, GA101 was more effective than RTX in important parameters, such as glomerulonephritis score. GA101 proved beneficial in an advanced disease model, where it prolonged survival. These data support clinical testing of GA101 in SLE and lupus nephritis.

The clinical efficacy of Rituximab administration in autoimmunity disorders, primary immunodeficiency diseases and malignancies

Rituximab (RTX), as a monoclonal antibody-based immunotherapeutic intervention targeting CD20 on B cells, has proven efficacy in the treatment of patients with some immune-mediated diseases. In the present review, we provided information on the immunobiological mechanisms of signaling for RTX and its clinical applications, according to the immune-pathophysiology involved in the microenvironment of multiple diseases. We highlighted combination therapy, dose schedules, and laboratory monitoring, as well as the associated common and rare side effects to avoid. We also discussed the efficacy and safety of RTX-based therapeutic strategies and whether RTX therapy can be used as a promising treatment regimen for autoimmune diseases, primary immunodeficiency diseases, and malignancies. Our review highlights and supports the importance of collaboration between basic medical researchers and clinical specialists when considering the use of RTX in the treatment of various immune-mediated disorders.

Stem Cell Therapy as a Treatment for Autoimmune Disease-Updates in Lupus, Scleroderma, and Multiple Sclerosis

PURPOSE OF REVIEW

Evidence for hematopoietic stem cell transplantation (HCT) in autoimmune disease has been building since the 1990s; however, many clinicians may not yet be aware of its applications to autoimmune disease. We review the basic tenets of HCT and evidence for autologous HCT in multiple sclerosis (MS), systemic sclerosis (SSc), and lupus with an emphasis on recent advanced phase trials.

RECENT FINDINGS

In MS, the phase 3 randomized MIST trial and the phase 2 randomized ASTIMS trial demonstrated the efficacy of autologous HCT in refractory MS over disease-modifying therapies and mitoxantrone, respectively. In SSc, the phase 3 randomized ASTIS trial and the phase 2 randomized SCOT trial demonstrated the efficacy of autologous HCT in advanced SSc compared to cyclophosphamide. The evidence for HCT in autoimmune diseases continues to grow, particularly in MS and SSc. In lupus, large, comparative trials are still needed. Across autoimmune diseases, questions that still remain to be answered include optimizing patient selection to limit TRM, the appropriate use of MAC, and the necessity for graft manipulation. Furthermore, collaboration between disease-specific and transplant physicians is imperative to expand the appropriate use of HCT in routine clinical practice.

Belimumab: a step forward in the treatment of systemic lupus erythematosus

Introduction: Systemic Lupus Erythematosus (SLE) is a chronic B cell-mediated autoimmune disease which can potentially involve several organs and systems. The development of SLE is associated with a complexity of genetic, hormonal and environmental factors leading to immune deregulation and production of autoantibodies. Therefore, novel therapies have focused on B cells as key effectors of SLE pathogenesis. Belimumab is a fully humanized monoclonal antibody that antagonizes B-lymphocyte stimulator (BLyS); it is the first and the only biological drug approved for SLE in over 50 years.Areas covered: In this review we discuss the pharmacological properties of belimumab, new recommendations for its use in clinical practice and its evidence of efficacy and safety based on clinical trial and real-life data.Expert opinion: Efficacy and safety of belimumab in clinical practice have been well established. To date, it is known that early introduction of belimumab in SLE can maximize the efficacy of the drug. A number of questions are still open, such as the timing of belimumab discontinuation and its possible association with other biological drugs, which need to be assessed in future studies.

Treatment of exostosin 1-associated membranous lupus nephritis with multiple low doses of rituximab: A case report

RATIONALE

Membranous glomerulonephritis (MN) is the leading cause of nephrotic syndrome in adults and is classified as primary or secondary. Secondary MN accounts for 20% to 30% of all MN cases and can arise from a number of conditions, including autoimmune diseases. Recently exostosin 1/exostosin 2 (EXT1/EXT2) have been identified as the common antigens in secondary autoimmune MN and are present in cases of pure membranous lupus nephritis (LN). The treatment of EXT1/EXT2-associated MN remains elusive.

PATIENT CONCERNS

We present the case of a 15-year-old female who presented with nephrotic syndrome, positive ANA and dsDNA, and low serum complements. A renal biopsy revealed pure membranous nephritis with IgG and C3 deposition. EXT1 was found along the glomerular capillary walls and stained positive, while phospholipase A2 receptor (PLA2R) and thrombospondin type-1 domain-containing 7A (THSD7A) were negative.

DIAGNOSIS

The patient was diagnosed with ETX1-associated membranous LN.

INTERVENTIONS

She was treated with prednisone and multiple low-dose rituximab (4 200 mg doses, approximately every 2 months, based on CD19+ cells counts).

OUTCOMES

The patient had complete remission within 8 months later, and she remained in remission for the 16-month period of follow-up.

LESSONS

To our knowledge, this is the first case of EXT1-associated MN that has been successfully treated by multiple low-dose rituximab. Further studies can investigate the optimal dosage and treatment protocol.

Safety and efficacy of low-dose intravenous arsenic trioxide in systemic lupus erythematosus: an open-label phase IIa trial (Lupsenic)

BACKGROUND

Lupus animal model has shown that arsenic trioxide (ATO), a treatment of acute promyelocytic leukaemia, could be effective in SLE. This is the first clinical study to determine the safety and efficacy of a short course of intravenous ATO in patients with active SLE.

METHODS

This phase IIa, open-label, dose-escalating study enrolled 11 adult SLE patients with a non-organ threatening disease, clinically active despite conventional therapy. Patients received 10 IV infusions of ATO within 24 days. The first group received 0.10 mg/kg per injection, with dose-escalating to 0.15 mg/kg in a second group, and to 0.20 mg/kg in a third group. The primary endpoint was the occurrence of adverse events (AEs) and secondary endpoints were the number of SLE Responder Index 4 (SRI-4) responders at week 24 and reduction of corticosteroid dosage. In an exploratory analysis, we collected long-term data for safety and attainment of lupus low disease activity state (LLDAS).

RESULTS

Four serious AEs occurred (grade 3 neutropenia, osteitis, neuropathy), 2 of which were attributable to ATO (neutropenia in the 2 patients treated with mycophenolate). Two patients suffered a severe flare during the last 4 weeks of the trial. At W24, five patients among 10 were SRI-4 responders. Overall, mean corticosteroid dosage decreased from 11.25 mg/day at baseline to 6 mg/day at W24 (P < 0.01). In the long term, 6 patients attained LLDAS at W52, which continued at last follow-up (median LLDAS duration 3 years, range 2-4).

CONCLUSIONS

A short course of ATO has an acceptable safety profile in SLE patients and encouraging efficacy.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01738360  registered 30 November 2012.

Molecular Signatures of Kidney Antibody-Secreting Cells in Lupus Patients With Active Nephritis Upon Immunosuppressive Therapy

OBJECTIVE

This study was undertaken to characterize kidney and urine antibody-secreting cells (ASCs) from patients with active lupus nephritis, before and after induction therapy.

METHODS

We included patients with biopsy-proven active lupus nephritis and performed anti-CD138 staining of kidney biopsy samples to visualize ASCs. We performed single-cell gene expression profiling on sorted ASCs from fresh biopsy samples using multiplex reverse transcriptase-polymerase chain reaction. We used a gene set that allowed for the study of ASC maturation from plasmablasts to long-lived plasma cells. We quantified urine ASCs from untreated patients with lupus nephritis at diagnosis and after 6 months of prospective follow-up during induction therapy.

RESULTS

The number of kidney CD138+ ASCs in 46 untreated patients with lupus nephritis was correlated with a low estimated glomerular filtration rate and with tubulointerstitial damage. Most kidney ASCs from 3 untreated patients had a plasmablast molecular signature; in contrast, in 4 patients with refractory lupus nephritis, the kidney ASCs were mainly long-lived plasma cells, representing an ASC transcriptional profile similar to that in the bone marrow of 2 healthy donors. Some urine ASCs with a plasmablast signature were detected in patients with untreated active lupus nephritis. The presence of urine ASCs at 6 months was associated with treatment failure.

CONCLUSION

Our results suggest potential for ASC-directed therapy in refractory lupus nephritis.

Lupus Membranous Nephropathy

Background

Lupus membranous nephropathy (LMN) is a rare disease, usually associated with nephrotic syndrome.

Methods

We reviewed the literature by searching for the following terms on Pubmed.gov: lupus nephritis, membranous nephropathy (MN), lupus membranous nephropathy, nephrotic syndrome, and Class V lupus nephritis.

Results

The histology of LMN at light microscopy is similar to that of primary MN. Cases of MN associated with focal or diffuse proliferation are not considered LMN by the International Society of Nephrology/Renal Pathology Society classification. Immunofluorescence study of LMN shows deposits of all immunoglobulins and complement. Tubulo-reticular structures, extraglomerular deposits, subepithelial, and scanty subendothelial deposits can be seen on electron microscopy. Phospholipase A2 receptor deposits are usually but not necessarily absent in LMN. The pathogenesis is still not completely understood. The inflammatory milieu of lupus may favor the development of autoantigens and intraglomerular assembly of immune complexes. These are more often associated with mesangial or endocapillary hypercellular lesions. Alternatively, autoantibodies may bind autoantigens in the glomerular subepithelium, triggering a signaling cascade leading to LMN. A central role in the development of podocyte injury and proteinuria is played by the components of complement C5b-C9. CKD progression in LMN is slow but may be accelerated by the frequency of renal flares. Persistent nephrotic syndrome and/or the frequent use of corticosteroids may lead to a series of life-threatening complications.

Discussion

Treatment of arterial hypertension, dyslipidemia, and diabetes are of paramount importance. Besides specific therapies of these complications, hydroxychloroquine and vitamin D supplementation are recommended. Immunosuppression should be limited to patients with nephrotic proteinuria. The most frequently used drugs are corticosteroids, calcineurin inhibitors, cyclophosphamide, mycophenolate, and rituximab, alone or combined. Early detection and treatment of renal flares is of paramount importance to prevent CKD progression.

Cellular aspects of the pathogenesis of lupus nephritis

PURPOSE OF REVIEW

Lupus nephritis is a common severe manifestation of systemic lupus erythematosus. Despite recent advances in therapeutics and understanding of its pathogenesis, there are still substantial unmet needs. This review discusses recent discoveries in these areas, especially the role of tubulointerstitial inflammation (TII) in lupus nephritis.

RECENT FINDINGS

Non-white ethnicity is still a major risk and poor prognostic factor in lupus nephritis. TII and fibrosis have been found to be associated with worse renal outcome but the current lupus nephritis treatment guidelines and trials are based on the degree of glomerular inflammation. In combination with mycophenolate mofetil, a B-cell-targeted therapy (belimumab) and a calcineurin inhibitor (voclosporin) have shown efficacy in recent lupus nephritis trials. However, response rates have been modest. While lupus glomerulonephritis results from immune complex deposition derived from systemic autoantibodies, TII arises from complex processes associated with in situ adaptive cell networks. These include local antibody production, and cognate or antigen-induced interactions between T follicular helper cells, and likely other T-cell populations, with antigen presenting cells including B cells, myeloid dendritic cells and plasmacytoid dendritic cells.

SUMMARY

Better understanding of the pathogenesis of TII will identify novel therapeutic targets predicted to improve outcomes in our patients with lupus nephritis.

The Use of Glucocorticoids in Lupus Nephritis: New Pathways for an Old Drug

Glucocorticoids therapy has greatly improved the outcome of lupus nephritis patients. Since their discovery, their adverse effects have counterbalanced their beneficial anti-inflammatory effects. Glucocorticoids exert their effects through both genomic and non-genomic pathways. Differential activation of these pathways is clinically relevant in terms of benefit and adverse effects. Ongoing aims in lupus nephritis treatment development focus on a better use of glucocorticoids combined with immunosuppressant drugs and biologics. Newer regimens aim to decrease the peak glucocorticoid dose, allow a rapid glucocorticoid tapering, and intend to control disease activity with a lower cumulative glucocorticoid exposure. In this review we discuss the mechanisms, adverse effects and recent strategies to limit glucocorticoid exposure without compromising treatment efficacy.

Obinutuzumab in Kidney Transplantation: Effect on B-cell Counts and Crossmatch Tests

BACKGROUND

Resistance to the action of rituximab (RTX) has been documented in several diseases. More recently, obinutuzumab (OBZ) has shown promise where RTX has failed in oncology and lupus nephritis. Unlike RTX, OBZ is a weak activator of complement, which may avoid the false-positive complement-dependent cytotoxicity (CDC) crossmatch tests after RTX infusions.

METHODS

The aim of this study was to explore the effect of OBZ on B-cell depletion in kidney-transplant candidates and its impact on crossmatch test results. We included 12 patients: who were either highly sensitized kidney-transplant candidates or kidney-transplant recipients presenting with antibody-mediated rejection. Six received OBZ and 6 received RTX. CD-19 counts, flow cytometry and CDC crossmatch tests were run immediately before and at 2 weeks after drug infusion.

RESULTS

OBZ reduced CD-19 counts: median reduction was 98%. B-cell CDC crossmatch test results became positive following RTX infusion but were not affected by OBZ infusion.

CONCLUSIONS

OBZ effectively depleted B-cell counts in sensitized kidney-transplant candidates and, unlike RTX, had no effect on CDC crossmatch results.

Biologic therapies for the treatment of systemic lupus erythematosus

Systemic lupus erythematosus is a typical autoimmune disease with a complex etiology, including the interaction of genetic/epigenetic factors and environmental and hormonal factors with innate immune cells or B/T lymphocytes. Studies on possible therapeutic targets have been conducted in recent decades, motivated by developments in immunology and molecular engineering. The current treatment guidelines recommend conventional immunomodulation with glucocorticoid and antimalarial agents depending on disease severity. However, targeted therapy based on the diverse disease pathophysiology is still not established and widely applied. Furthermore, although rituximab, belimumab, and other conventional immunomodulators have been approved by the Food and Drug Administration and are widely used, several clinical trials testing other biological products have failed to show satisfactory results. This review introduces novel biological agents that can potentially improve therapeutic performance in patients with systemic lupus erythematosus. These agents include humanized anti-CD20, anti-CD22, and anti-CD40L antibody; interferon α inhibitor; rigerimod; Bruton’s tyrosine kinase; and immunocomplex blockers.

Management of Lupus Nephritis

Lupus nephritis (LN) is a frequent and severe manifestation of systemic lupus erythematosus. The main goal of the management of LN is to avoid chronic kidney disease (CKD). Current treatment strategies remain unsatisfactory in terms of complete renal response, prevention of relapses, CKD, and progression to end-stage kidney disease. To improve the prognosis of LN, recent data suggest that we should (i) modify our treat-to-target approach by including, in addition to a clinical target, a pathological target and (ii) switch from conventional sequential therapy to combination therapy. Here, we also review the results of recent controlled randomized trials.

B Cell Aberrance in Lupus: the Ringleader and the Solution

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease with high heterogeneity but the common characterization of numerous autoantibodies and systemic inflammation which lead to the damage of multiple organs. Aberrance of B cells plays a pivotal role in the immunopathogenesis of SLE via both antibody-dependent and antibody-independent manners. Escape of autoreactive B cells from the central and peripheral tolerance checkpoints, over-activation of B cells and their excessive cytokines release which drive T cells and dendritic cells stimulation, and dysregulated surface molecules, as well as intracellular signal pathways involved in B cell biology, are all contributing to B cell aberrance and participating in the pathogenesis of SLE. Based on that rationale, targeting aberrance of B cells and relevant molecules and pathways is expected to be a promising strategy for lupus control. Multiple approaches targeting B cells through different mechanisms have been attempted, including B-cell depletion via monoclonal antibodies against B-cell-specific molecules, blockade of B-cell survival and activation factors, suppressing T-B crosstalk by interrupting costimulatory molecules and inhibiting intracellular activation signaling cascade by targeting pathway molecules in B cells. Though most attempts ended in failure, the efficacy of B-cell targeting has been encouraged by the FDA approval of belimumab that blocks B cell-activating factor (BAFF) and the recommended use of anti-CD20 as a remedial therapy in refractory lupus. Still, quantities of clinical trials targeting B cells or relevant molecules are ongoing and some of them have displayed promising preliminary results. Additionally, advances in multi-omics studies help deepen our understandings of B cell biology in lupus and may promote the discovery of novel potential therapeutic targets. The combination of real-world data with basic research achievements may pave the road to conquering lupus.

A Prospective Study on Long-Term Clinical Outcomes of Patients With Lupus Nephritis Treated With an Intensified B-Cell Depletion Protocol Without Maintenance Therapy

Background

We aimed to investigate the safety and efficacy of an intensified B-cell depletion induction therapy (IBCDT) without immunosuppressive maintenance regimen compared with standard of care in biopsy-proven lupus nephritis (LN).

Methods

Thirty patients were administered an IBCDT (4 weekly rituximab [RTX] 375 mg/m² and 2 more doses after 1 and 2 months; 2 infusions of 10 mg/kg cyclophosphamide [CYC], 3 methylprednisolone pulses), followed by oral prednisone (tapered to 5 mg/d by the third month). No immunosuppressive maintenance therapy was given. Thirty patients matched for LN class and age were selected as controls: 20 received 3 methylprednisolone pulses days followed by oral prednisone and mycophenolate mofetil (MMF) 2 to 3 g/d, whereas 10 were given the Euro Lupus CYC. MMF (1-2 g/daily) or azathioprine (AZA, 1-2 mg/kg/day) were given for > 3 years as a maintenance therapy.

Results

At 12 months, complete renal remission was observed in 93% of patients on IBCDT, in 62.7% on MMF, and in 75% on CYC (P = 0.03); the dose of oral prednisone was lower in the IBCDT group (mean ± SD 2.9 ± 5.0 mg/dl) than MMF (10.5 ± 8.0 mg/d, P < 0.01) or CYC group (7.5 ± 9.0 mg/d, P < 0.01). Mean follow-up after treatment was 44.5 months (interquartile range [IQR] 36-120 months), 48.6 months (IQR 36-120 months), and 45.3 (IQR 36-120 months) for IBCDT, MMF, and CYC, respectively. At their last follow-up visit, we observed no significant differences in proteinuria and serum creatinine, nor in the frequency of new flares among the 3 groups.

Conclusion

In biopsy-proven LN, the IBCDT without further immunosuppressive maintenance therapy was shown to be as effective as conventional regimen of MMF or CYC followed by >3-year maintenance either MMF or AZA regimen. Moreover, the use of IBCDT was associated with a marked reduction of glucocorticoid cumulative dose.

Targeted Biologic Therapy for Systemic Lupus Erythematosus: Emerging Pathways and Drug Pipeline

Following the approval of belimumab, the first drug to be approved for systemic lupus erythematosus (SLE) in over 50 years, advances in our understanding of the pathogenesis of the disease have led to a remarkable number of clinical trials for investigational drugs, each with a unique mechanism of action. These include, but are not limited to, antibodies targeting B or T cells or their interaction, dendritic cells, interferon, and other cytokines. Frustratingly, this boost of studies has not been accompanied by a corresponding success and subsequent approval of novel agents, for reasons only partly attributed to the efficacy of the drugs per se. Successful phase II trials are often followed by failed phase III studies, which typically require many more patients. Nevertheless, recent successes, such as the ustekinumab and baricitinib trials and the positive results from the phase III TULIP-2 study of anifrolumab, provide room for cautious optimism. In this review, we attempt to draw the current landscape of the drug pipeline in SLE, focusing on the rationale behind each drug development, its mechanism of action, and the available preclinical and clinical data. We also highlight lessons learned from failed attempts that have helped to optimize clinical trial design for this challenging disease. We conclude with a look into the future, commenting on the surge of studies in the field of biomarkers and the use of omics technologies in lupus, which aim to pinpoint different disease phenotypes and, ideally, identify subsets of patients with disease that will respond to different biologic drugs.

Treating systemic lupus erythematosus in the 21st century: new drugs and new perspectives on old drugs

Besides treating acute flares, the management of SLE should aim at preventing organ damage accrual and drug-associated harms, improving health-related quality of life and prolonging survival. At present, therapy is based on combinations of antimalarials (mainly HCQ), considered the backbone of SLE treatment, glucocorticoids and immunosuppressive drugs. However, these regimens are not universally effective and a substantial degree of damage can be caused by exposure to glucocorticoids. In this review we provide a critical appraisal of the efficacy and safety of available treatments as well as a brief discussion of potentially novel compounds in patients with SLE. We emphasize the use of methylprednisolone pulses for moderate–severe flares, followed by low–moderate doses of oral prednisone with quick tapering to maintenance doses of ≤5 mg/day, as well as the prompt institution of immunosuppressive drugs in the setting of severe disease but also as steroid-sparing agents. Indications for the use of biologic agents, namely belimumab and rituximab, in refractory or organ-threatening disease are also presented. We conclude by proposing evidence- and experience-based treatment strategies tailored to the clinical scenario and prevailing organ involvement that can aid clinicians in managing this complex disease.

Analysis of trends and causes of death in SLE patients over a 40-years period in a cohort of patients in the United Kingdom

BACKGROUND

Systemic Lupus Erythematosus (SLE) an autoimmune rheumatic disease with a complex pathogenesis, remains potentially life-threatening. SLE patients have increased morbidity and premature mortality compared to non-SLE patients. The five-year survival rate has improved from <50% in the 1950s to >90% in the 1980s. Lupus patients still have a mortality risk three times that of the general population.

OBJECTIVES

To provide a detailed analysis of the causes of death, main characteristics and trends in the management of the deceased SLE patients from the lupus clinic at the University College London Hospital (UCLH); during the past four decades.

METHODS

This was a non-interventional, retrospective study based on historical real-world data from paper and electronic records of patients followed up at UCLH. The analysis focused on data collected between 1st January 1978 and 31th December 2018. We collected the: causes of death, duration of disease, key laboratory and clinical parameters and the treatment received. We compared the results from the four decades to ascertain trends in the causes of mortality. All statistical analyses were performed using the Statistical Package for Social Sciences (SPSS), version 22.0. The 95% confidence intervals for the means of data were calculated.

RESULTS

111 SLE patients (15%), died during follow-up. Their median age was 51 years (interquartile range (IQR) = 38-63 years) and the median duration of disease, 15 years (IQR = 8.5-24 years). The main causes of death in the past 40 years were infection (31.7%), cancer (26.7%) and cardiovascular disease (CVD) (21.8%). 93.6% of these patients were immunosupressed. During the 40-year period, there were several therapeutic developments notably the introduction of mycophenolate mofetil (MMF) and rituximab; the latter initially only given to patients when more conventional inmunosupressants had failed, but more recently offered to patients at diagnosis. There was a statistically significant increase in the use of hydroxycloroquine (HCQ), MMF and rituximab. In contrast, the use of Azathioprine (AZA) and steroids, hardly changed over time.

CONCLUSIONS

This retrospective review shows how epidemiological factors, causes of death and treatment of SLE patients have changed during the last 40 years in the UCLH cohort.

Rituximab - The first twenty years

It is now two decades since Rituximab was first used in the treatment of patients with systemic lupus erythematosus. There have been many challenges but in spite of failing to meet its primary endpoints in two clinical trials it is widely used for many aspects of lupus, its side-effects and the possibility that combining it with Benlysta may be of value. We also consider the proposal that it may provide a useful initial therapy. In this review, we consider the place of Rituximab in the treatment of lupus and anticipate how developments in fully-humanized anti-CD20 monoclonals may well extend the "therapeutic life" of B-cell depletion as a viable treatment option.

Therapeutic Targeting of Autoreactive B Cells: Why, How, and When?

B lymphocytes play critical roles in the development of autoimmunity, acting as autoantibody manufacturers, antigen-presenting cells, and producers of cytokines. Pan-B cell depletion has demonstrated efficacy in treatment of many autoimmune disorders, but carries with it an unfavorable safety profile due to global immune suppression. Hence, attention has turned to the potential of autoantigen-specific B cell targeted therapies, which would deplete or silence pathogenic self-antigen-reactive cells while sparing B cells needed for immune defense. Here, we discuss the antigen-specific B cell-targeted approaches that are under development or are under consideration, that could be employed to allow for more precise therapy in the treatment of autoimmunity. Lastly, we discuss some of the challenges associated with antigen-specific B cell targeting that may impact their clinical applicability.

Efficacy and safety of rituximab in the treatment of connective tissue disease-related interstitial lung disease

Interstitial lung disease (ILD) represents a severe pulmonary complication of connective tissue diseases, rheumatoid arthritis (RA), and antineutrophil cytoplasmic antibody-associated vasculitis. Treatment of ILD, mainly based on immunosuppression, remains challenging. Rituximab (RTX), a monoclonal antibody binding to CD20, is considered a valuable therapeutic choice in cases of refractory ILD. Here, we review the available efficacy and safety data on the use of RTX in the treatment of rheumatic disease-related ILD. Despite controversial efficacy data, RTX seems to be able to stabilize or improve ILD related to RA and antisynthetase syndrome and in established and severe ILD complicating systemic sclerosis. Fewer data are available regarding ILD related to Sjögren syndrome, systemic lupus erythematosus, and antineutrophil cytoplasmic antibody-associated vasculitis. To date, few prospective studies are available and randomized trials are still ongoing with the purpose of exploring the role of RTX in this condition, including the supposed relationship between efficacy and ILD radiologic patterns and safety data, up to now derived mainly from RA studies. Despite an overall acceptable safety profile, concerns remain regarding an increased infectious disease risk in patients with ILD as well as possible lung toxicity and the increased rate of immune-mediated reactions in patients with connective tissue diseases. In conclusion, RTX is a relevant therapeutic option for rheumatic disease-related ILD despite the existing uncertainties; ongoing trials are expected to clarify its use.

The peptide symporter SLC15a4 is essential for the development of systemic lupus erythematosus in murine models

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease representing a serious unmet medical need. The disease is associated with the loss of self-tolerance and exaggerated B cell activation, resulting in autoantibody production and the formation of immune complexes that accumulate in the kidney, causing glomerulonephritis. TLR7, an important mediator of the innate immune response, drives the expression of type-1 interferon (IFN), which leads to expression of type-1 IFN induced genes and aggravates lupus pathology. Because the lysosomal peptide symporter slc15a4 is critically required for type-1 interferon production by pDC, and for certain B cell functions in response to TLR7 and TLR9 signals, we considered it as a potential target for pharmacological intervention in SLE. We deleted the slc15a4 gene in C57BL/6, NZB, and NZW mice and found that pristane-challenged slc15a4-/- mice in the C57BL/6 background and lupus prone slc15a4-/- NZB/W F1 mice were both completely protected from lupus like disease. In the NZB/W F1 model, protection persisted even when disease development was accelerated with an adenovirus encoding IFNα, emphasizing a broad role of slc15a4 in disease initiation. Our results establish a non-redundant function of slc15a4 in regulating both innate and adaptive components of the immune response in SLE pathobiology and suggest that it may be an attractive drug target.

Emerging B-Cell Therapies in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic, multisystem, autoimmune disease of unknown etiology, whose hallmark is the production of autoantibodies. B cells are promising targets for novel SLE therapies. In 2011, belimumab (Benlysta®), a fully humanized monoclonal antibody inhibiting B-cell activation and proliferation, was the first medication in 50 years to be approved by the US Food and Drug Administration to treat adult SLE. This review discusses the current experience with B-cell-targeted therapies, including those targeting B-cell-surface antigens (rituximab, ocrelizumab, ofatumumab, obinutuzumab, obexelimab, epratuzumab, daratumumab), B-cell survival factors (belimumab, tabalumab, atacicept, blisibimod), or B-cell intracellular functions (ibrutinib, fenebrutinib, proteasome inhibitors), for the management of SLE. It focuses on ongoing clinical trials and real-world post-marketing use, where available, including their safety profiles, and concludes with our recommendations for B-cell-centric approaches to the management of SLE.

Infectious Complications in Patients with Primary Glomerulonephritis over 10 Years: A Single-Center Experience in Turkey

INTRODUCTION

Infections can play an important role in the mortality and morbidity of patients with glomerulonephritis. However, the frequency of infectious complications in primary glomerulonephritis and their burden to the healthcare managements are not clear.

METHODS

We evaluated the infectious complications in patients with biopsy-proven focal segmental glomerulosclerosis, membranous glomerulonephritis, IgA nephropathy, minimal change disease, membranoproliferative glomerulonephritis, and chronic glomerulonephritis during the last 10 years in a single center. We recorded the demographic, clinical, and laboratory characteristics; treatment modalities; infectious episodes; and infection-related mortality and morbidity of the patients.

RESULTS

Of the patients, 154 (63.6%) received immunosuppressive treatment and 88 (34.4%) were followed up under conservative treatment. Overall, 118 infectious episodes were noted in 64 patients, with an infection rate of 0.20 per patient-year. Total infectious complications were higher in the immunosuppressive group than in the conservative group (42.1 vs. 23.3%, p = 0.005). Infection-related hospitalizations were also higher in the immunosuppressive group (p = 0.01). The most frequently infected area was the lungs (15.7%). Although bacterial infections were the most common in both groups, 14.9% of the immunosuppressive group had cytomegalovirus (CMV) replication. Age >50 years (OR 2.19, p = 0.03), basal serum albumin <2.5 g/dL (OR 2.28, p = 0.02), cyclophosphamide (OR 2.43, p = 0.02), and cyclosporine (OR 2.30, p = 0.03) were independently associated with experiencing infectious episodes.

CONCLUSIONS

Because of high seropositivity for CMV in Turkey, it might be a wise approach to use prophylactic antiviral drugs in patients treated with immunosuppressive treatments. Close monitoring of patients with primary glomerulonephritis, especially those treated with immunosuppressive therapy, is important for reducing infection-related morbidity and mortality.

Anti-CD20 monoclonal antibodies in Systemic Lupus Erythematosus

Systemic Lupus Erythematosus (SLE) is an autoimmune inflammatory condition with a wide spectrum of disease manifestations and severities, resulting in significant morbidity and mortality. The aetiopathogenesis of SLE is complex. Young women and certain ethnicities are commonly affected, suggesting a significant hormonal and genetic influence. Diverse immunological abnormalities have been described. A characteristic abnormality is the presence of autoantibodies, implicating a central role for B cells in disease pathogenesis and/or perpetuation. Whilst conventional therapies have improved outcomes, a great unmet need remains. Recently, biological therapies are being explored. B-cell depletion therapy with rituximab has been in use off-label for nearly two decades. Inconsistent results between uncontrolled and controlled studies have raised doubts about its efficacy. In this review, we will focus on B cell abnormalities and the rationale behind B-cell depletion therapy with anti-CD20 monoclonal antibody (mAb), rituximab, will be explored including an evaluation of clinical and trial experience. Finally, we will discuss the mechanistic basis for considering alternative anti-CD20 mAbs.

B cell depletion therapies in autoimmune disease: advances and mechanistic insights

In the past 15 years, B cells have been rediscovered to be not merely bystanders but rather active participants in autoimmune aetiology. This has been fuelled in part by the clinical success of B cell depletion therapies (BCDTs). Originally conceived as a method of eliminating cancerous B cells, BCDTs such as those targeting CD20, CD19 and BAFF are now used to treat autoimmune diseases, including systemic lupus erythematosus and multiple sclerosis. The use of BCDTs in autoimmune disease has led to some surprises. For example, although antibody-secreting plasma cells are thought to have a negative pathogenic role in autoimmune disease, BCDT, even when it controls the disease, has limited impact on these cells and on antibody levels. In this Review, we update our understanding of B cell biology, review the results of clinical trials using BCDT in autoimmune indications, discuss hypotheses for the mechanism of action of BCDT and speculate on evolving strategies for targeting B cells beyond depletion.

CD62L on blood basophils: a first pre-treatment predictor of remission in severe lupus nephritis

BACKGROUND

Basophils were recently shown to contribute to lupus nephritis (LN). This study assessed blood basophil activation markers (BAMs) for the diagnosis of LN severity and as pre-treatment prognostic markers of the response to treatment in patients with severe LN.

METHOD

The diagnostic study included all the patients of a monocentric prospective observational cohort built with consecutive patients diagnosed with LN on the basis of a renal biopsy. The prognostic study selected patients of this cohort according to the following inclusion criteria: ≥18 years old, Class III or IV A ± C ± Class V or pure Class V LN at the time of inclusion and treated with an induction treatment for LN. Clinical data and BAMs were obtained at the time of the kidney biopsy. LN remission status was recorded 12 months after induction therapy initiation. Associations between baseline data and histological severity of LN or LN remission were assessed using logistic regression.

RESULTS

No significant association was found between BAMs and the histological severity of LN in 101 patients. Among the 83 patients included in the prognostic study, 64 reached renal remission. CD62L expression on blood basophils at baseline was independently negatively associated with remission at 12 months [odds ratio = 0.26, 95% confidence interval 0.08-0.82, P = 0.02 for quantitative CD62L expression >105 (geometric fluorescent intensity) gMFI]. CD62L <105 gMFI was associated with a probability of 0.87 of LN remission in the next 12 months after the start of induction therapy.

CONCLUSION

Pre-treatment CD62L expression on blood basophils could be a first predictive biomarker of renal response to induction therapy at 12 months in patients with severe LN.

The growing role of precision medicine for the treatment of autoimmune diseases; results of a systematic review of literature and Experts' Consensus

Autoimmune diseases (AIDs) share similar serological, clinical, and radiological findings, but, behind these common features, there are different pathogenic mechanisms, immune cells dysfunctions, and targeted organs. In this context, multiple lines of evidence suggest the application of precision medicine principles to AIDs to reduce the treatment failure. Precision medicine refers to the tailoring of therapeutic strategies to the individual characteristics of each patient, thus it could be a new approach for management of AIDS which considers individual variability in genes, environmental exposure, and lifestyle. Precision medicine would also assist physicians in choosing the right treatment, the best timing of administration, consequently trying to maximize drug efficacy, and, possibly, reducing adverse events. In this work, the growing body of evidence is summarized regarding the predictive factors for drug response in patients with AIDs, applying the precision medicine principles to provide high-quality evidence for therapeutic opportunities in improving the management of these patients.

Systemic lupus erythematosus: The search for the ideal biomarker

During the last decades, there has been an increased interest in the discovery and validation of biomarkers that reliably reflect specific aspects of lupus. Although many biomarkers have been developed, few of them have been validated and used in clinical practice, but with unsatisfactory performances. Thus, there is still a need to rigorously validate many of these novel promising biomarkers in large-scale longitudinal studies and also identify better biomarkers not only for lupus diagnosis but also for monitoring and predicting upcoming flares and response to treatment. Besides serological biomarkers, urinary and cerebrospinal fluid biomarkers have emerged for assessing both renal and central nervous system involvement in systemic lupus erythematosus, respectively. Also, novel omics techniques help us to understand the molecular basis of the disease and also allow the identification of novel biomarkers which may be potentially useful for guiding new therapeutic targets.

Lupus nephritis: clinical presentations and outcomes in the 21st century

Lupus nephritis (LN) is a frequent and severe manifestation of SLE. Along the decades, the epidemiology of LN and its clinical presentation have been changing. However, even though retrospective cohort studies report a decreased mortality rate and an improvement in the disease prognosis, the percentage of patients progressing into end stage renal disease (ESRD) keeps steady despite the improvements in therapeutic strategies. Current in-use medications have been available for decades now, yet over the years, regimens for optimizing their efficacy and minimizing toxicity have been developed. Therapeutic research is now moving towards the direction of precision medicine and several new drugs, targeting selectively different pathogenetic pathways, are currently under evaluation with promising results. In this review, we address the main changes and persistent unmet needs in LN management throughout the past decades, with a focus on prognosis and upcoming treatments.

Novel strategies to target the humoral alloimmune response

Antibody-mediated rejection (ABMR) represents a major cause of late allograft loss in solid organ transplantation worldwide. This process is driven by donor-specific antibodies (DSA), which develop either de-novo or, in sensitized patients, are preformed at the time of transplantation. Effective targeting of ABMR has been hampered by a lack of robust randomized controlled trials (RCT), required for the regulatory approval of new therapeutics. In this review, we discuss the evidence behind the present "standard" of care and recent progress in the development of novel strategies targeting different aspects of the alloimmune humoral response, including naïve and memory B-cell activation, the germinal centre reaction, plasma cell survival and antibody effector functions. In particular, we focus on co-stimulation blockade and its combination with next-generation proteasome inhibitors, new depleting monoclonal antibodies (anti-CD19, anti-BCMA, anti-CD38, anti-CD138), interleukin-6 blockade, complement inhibition and DSA degradation. These treatment modalities, when used in the appropriate clinical context and combination, have the potential to finally improve long-term allograft survival.

Phase II Randomized Trial of Rituximab Plus Cyclophosphamide Followed by Belimumab for the Treatment of Lupus Nephritis

Objective

To assess the safety, mechanism of action, and preliminary efficacy of rituximab followed by belimumab in the treatment of refractory lupus nephritis (LN).

Methods

In a multicenter, randomized, open‐label clinical trial, 43 patients with recurrent or refractory LN were treated with rituximab, cyclophosphamide (CYC), and glucocorticoids followed by weekly belimumab infusions until week 48 (RCB group), or treated with rituximab and CYC but no belimumab infusions (RC group). Patients were followed up until week 96. Percentages of total and autoreactive B cell subsets in the patients’ peripheral blood were analyzed by flow cytometry.

Results

Treatment with belimumab did not increase the incidence of adverse events in patients with refractory LN. At week 48, a complete or partial renal response occurred in 11 (52%) of 21 patients receiving belimumab, compared to 9 (41%) of 22 patients in the RC group who did not receive belimumab (P = 0.452). Lack of improvement in or worsening of LN was the major reason for treatment failure. B cell depletion occurred in both groups, but the percentage of B cells remained lower in those receiving belimumab (geometric mean number of B cells at week 60, 53 cells/μl in the RCB group versus 11 cells/μl in the RC group; P = 0.0012). Percentages of total and autoreactive transitional B cells increased from baseline to week 48 in both groups. However, percentages of total and autoreactive naive B cells decreased from baseline to week 48 in the belimumab group compared to the no belimumab RC group (P = 0.0349), a finding that is consistent with the observed impaired maturation of naive B cells and enhanced censoring of autoreactive B cells.

Conclusion

The addition of belimumab to a treatment regimen with rituximab and CYC was safe in patients with refractory LN. This regimen diminished maturation of transitional to naive B cells during B cell reconstitution, and enhanced the negative selection of autoreactive B cells. Clinical efficacy was not improved with rituximab and CYC in combination with belimumab when compared to a therapeutic strategy of B cell depletion alone in patients with LN.

The Dawn of a New Era of Therapies in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a complicated multisystem autoimmune disease that is associated with significant mortality and morbidity in the younger population. The development of novel therapies of SLE lag behinds other autoimmune inflammatory rheumatic diseases because of its clinical and immunological heterogeneities, the complexity of outcome assessments in multiple systems, and difficulty in optimizing the design of clinical trials. Despite the futility of quite a number of clinical trials, we are seeing the dawn of novel therapeutics in SLE, given the promising results of the newer-generation anti-CD20, anti-CD40L biologics, and calcineurin inhibitors (CNIs), as well as anti-cytokine biologics, Jakinibs, and the mammalian target of rapamycin (mTOR) inhibitors. The initial success of the Jakinibs and combination regimens in SLE illustrates the importance of targeting multiple pathogenetic mechanisms. The results of the ongoing phase III clinical trials in SLE are eagerly awaited.

A novel BAFF antagonist, BAFF-Trap, effectively alleviates the disease progression of systemic lupus erythematosus in MRL/lpr mice

Abnormal B cells, which produce antibodies against self-antigens, play a key role in the pathogenesis of autoimmune diseases, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). B-cell activating factor (BAFF) is closely associated with abnormal B cells and participates in B cell-mediated autoimmune diseases; thus, neutralizing BAFF is an effective method for treating these diseases. Our group designed a novel fusion protein, BAFF-Trap, that contains the BAFF-binding domains of two BAFF receptors (TACI and BAFF-R) and the Fc domain of human IgG1. In this study, we showed that BAFF-Trap significantly decreased the autoantibody levels, BAFF concentrations and B cells numbers in MRL/lpr mice. BAFF-Trap suppressed the expression of pro-inflammatory cytokines in the kidney and decreased the frequencies of T cell subsets and dendritic cells. Furthermore, BAFF-Trap reduced proteinuria and IgG deposition, relieved glomerular damage in the kidney, and markedly improved the survival rate of mice. These results indicated that BAFF-Trap may be a potential drug for the treatment of SLE.

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

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

B-cell depletion or belimumab or voclosporin for lupus nephritis?

PURPOSE OF REVIEW

Despite ground-breaking innovations for most autoimmune diseases, the treatment of lupus nephritis has remained largely the same for decades because none of the tested drugs demonstrated superiority over standard-of-care in randomized controlled clinical trials.

RECENT FINDINGS

Recently, the Belimumab in Subjects with Systemic Lupus Erythematosus - Lupus Nephritis trial tested belimumab, an inhibitor of B-cell activating factor, as an add-on therapy to steroids and either mycophenolate mofetil (MMF) or cyclophosphamide when given IV monthly over a period of 104 weeks at an effect size of 11% for a Primary Efficacy Renal Response. The NOBILITY trial reported positive results for the B-cell-depleting agent obinutuzumab as an add-on therapy to steroids and MMF when given IV every 6 months over a period of 76 weeks at an effect size of 22% for a complete renal response (CRR). The AURORA trial reported positive results for the calcineurin inhibitor voclosporin as an oral add-on therapy to low dose steroids and MMF when given twice daily over a period of 52 weeks at an effect size of 18.5% for a CRR.

SUMMARY

These studies will change the treatment landscape of lupus nephritis. In which way is discussed in this article.

Management of Severe Refractory Systemic Lupus Erythematosus: Real-World Experience and Literature Review

Systemic lupus erythematosus (SLE) is a highly heterogeneous disease affecting multiple organs and is characterized by an aberrant immune response. Although the mortality of SLE has decreased significantly since the application of glucocorticoids, severe or refractory SLE can potentially cause irreversible organ damage and contribute to the disease morbidity and mortality. Early recognition of severe SLE or life-threatening conditions is of great challenge to clinicians since the onset symptoms can be rapid and aggressive, involving the visceral organs of the neuropsychiatric, gastrointestinal, hematologic, renal, pulmonary, and cardiovascular systems, etc. Additionally, SLE patients with specific comorbidities and detrimental complications could lead to a clinical dilemma and contribute to poor prognosis. Prompt and adequate treatment for severe refractory SLE is crucial for a better prognosis. However, as evidence from well-designed randomized controlled trials is limited, this review aims to provide real-world evidence based on cohort studies from Peking Union Medical College Hospital, the national tertiary referral center in China, together with the literature, on clinical characteristics, risks and prognostic factors, and treatment strategies for severe and/or refractory SLE.

Analysis of Trans-Ancestral SLE Risk Loci Identifies Unique Biologic Networks and Drug Targets in African and European Ancestries

Systemic lupus erythematosus (SLE) is a multi-organ autoimmune disorder with a prominent genetic component. Individuals of African ancestry (AA) experience the disease more severely and with an increased co-morbidity burden compared to European ancestry (EA) populations. We hypothesize that the disparities in disease prevalence, activity, and response to standard medications between AA and EA populations is partially conferred by genomic influences on biological pathways. To address this, we applied a comprehensive approach to identify all genes predicted from SNP-associated risk loci detected with the Immunochip. By combining genes predicted via eQTL analysis, as well as those predicted from base-pair changes in intergenic enhancer sites, coding-region variants, and SNP-gene proximity, we were able to identify 1,731 potential ancestry-specific and trans-ancestry genetic drivers of SLE. Gene associations were linked to upstream and downstream regulators using connectivity mapping, and predicted biological pathways were mined for candidate drug targets. Examination of trans-ancestral pathways reflect the well-defined role for interferons in SLE and revealed pathways associated with tissue repair and remodeling. EA-dominant genetic drivers were more often associated with innate immune and myeloid cell function pathways, whereas AA-dominant pathways mirror clinical findings in AA subjects, suggesting disease progression is driven by aberrant B cell activity accompanied by ER stress and metabolic dysfunction. Finally, potential ancestry-specific and non-specific drug candidates were identified. The integration of all SLE SNP-predicted genes into functional pathways revealed critical molecular pathways representative of each population, underscoring the influence of ancestry on disease mechanism and also providing key insight for therapeutic selection.