Clinical efficacy and safety of sirolimus in systemic lupus erythematosus: a real-world study and meta-analysis

Current cell therapies for systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease in which multiple organs are damaged by the immune system. Although standard treatment options such as hydroxychloroquine (HCQ), glucocorticoids (GCs), and other immunosuppressive or immune-modulating agents can help to manage symptoms, they do not offer a cure. Hence, there is an urgent need for the development of novel drugs and therapies. In recent decades, cell therapies have been used for the treatment of SLE with encouraging results. Hematopoietic stem cell transplantation, mesenchymal stem cells, regulatory T (Treg) cell, natural killer cells, and chimeric antigen receptor T (CAR T) cells are advanced cell therapies which have been developed and evaluated in clinical trials in humans. In clinical application, each of these approaches has shown advantages and disadvantages. In addition, further studies are necessary to conclusively establish the safety and efficacy of these therapies. This review provides a summary of recent clinical trials investigating cell therapies for SLE treatment, along with a discussion on the potential of other cell-based therapies. The factors influencing the selection of common cell therapies for individual patients are also highlighted.

Potential therapies targeting metabolic pathways in systemic lupus erythematosus

The pathophysiology of systemic lupus erythematosus (SLE) is multifactorial and involves alterations in metabolic pathways, including glycolysis, lipid metabolism, amino acid metabolism, and mitochondrial dysfunction. Increased glycolysis in SLE T cells, which is associated with elevated glucose transporter 1 expression, suggests targeting glucose transporters and hexokinase as potential treatments. Abnormalities in lipid metabolism, particularly in lipid rafts and enzymes, present new therapeutic targets. This review discusses how changes in glutaminolysis and tryptophan metabolism affect T-cell function, suggesting new therapeutic interventions, as well as mitochondrial dysfunction in SLE, which increases reactive oxygen species. The review also emphasizes that modulating metabolic pathways in immune cells is a promising approach for SLE treatment, and can facilitate personalized therapies based on individual metabolic profiles of patients with SLE. The review provides novel insights into strategies for managing SLE.

Beyond FOXP3: a 20-year journey unravelling human regulatory T-cell heterogeneity

The initial idea of a distinct group of T-cells responsible for suppressing immune responses was first postulated half a century ago. However, it is only in the last three decades that we have identified what we now term regulatory T-cells (Tregs), and subsequently elucidated and crystallized our understanding of them. Human Tregs have emerged as essential to immune tolerance and the prevention of autoimmune diseases and are typically contemporaneously characterized by their CD3+CD4+CD25high CD127lowFOXP3+ phenotype. It is important to note that FOXP3+ Tregs exhibit substantial diversity in their origin, phenotypic characteristics, and function. Identifying reliable markers is crucial to the accurate identification, quantification, and assessment of Tregs in health and disease, as well as the enrichment and expansion of viable cells for adoptive cell therapy. In our comprehensive review, we address the contributions of various markers identified in the last two decades since the master transcriptional factor FOXP3 was identified in establishing and enriching purity, lineage stability, tissue homing and suppressive proficiency in CD4+ Tregs. Additionally, our review delves into recent breakthroughs in innovative Treg-based therapies, underscoring the significance of distinct markers in their therapeutic utilization. Understanding Treg subsets holds the key to effectively harnessing human Tregs for immunotherapeutic approaches.

Sirolimus for the treatment of patients with refractory connective tissue disease-related thrombocytopenia: a pilot study

OBJECTIVE

CTD-related immune thrombocytopenia (CTD-ITP) represents an unmet medical need because the drugs that are available are only partly effective and have considerable side-effects. The aim of this study was to assess the efficacy and safety of sirolimus in refractory CTD-ITP patients.

METHODS

We did a single-arm, open-label, pilot study of sirolimus in patients with CTD-ITP unresponsive to, or intolerant of, conventional medications. Patients received oral sirolimus for 6 months at a starting dose of 0.5-1 mg per day, with dose adjusted according to tolerance and to maintain a therapeutic range of 6-15 ng/ml. The primary efficacy end point was changes in platelet count, and overall response assessed according to the ITP International Working Group Criteria. Safety outcomes included tolerance as assessed by the occurrence of common side-effects.

RESULTS

Between November 2020 and February 2022, 12 consecutively hospitalized patients with refractory CTD-ITP were enrolled and prospectively followed. Of these, six patients (50%) achieved complete response, two (16.7%) achieved partial response, and four (33.3%) were no response under therapy. Three of four patients with primary Sjögren's syndrome and two of three patients with systemic lupus erythematosus achieved overall response. One of two patients with overlapping Sjögren's syndrome and systemic lupus erythematosus achieved complete response at 6 months. No severe drug-related toxicities were observed.

CONCLUSION

Our results do support sirolimus as an alternative regimen for refractory CTD-ITP patients, including systemic lupus erythematosus and primary SS.

Immunotherapeutic approaches for systemic lupus erythematosus: early overview and future potential

Systemic lupus erythematosus (SLE) is a complex autoimmune disease. Current SLE therapies include immunosuppressants, antimalarial drugs, non-steroidal anti-inflammatory drugs (NSAIDs), and corticosteroids, but these treatments can cause substantial toxicities to organs and may not be effective for all patients. In recent years, significant progress has been made in the treatment of SLE using immunotherapy, including Benlysta and Saphnelo. These advances in immunotherapy hold promise for SLE patients, providing new therapeutic options that may offer better clinical benefit and effectiveness. Simultaneously, several new biological therapies focusing on cytokines, peptides, targeted antibodies, and cell-based approaches are under clinical evaluation and have shown immense potential for the treatment of SLE. However, the complexity of SLE immunopathogenesis and disease heterogeneity present significant challenges in the development of effective immunological therapies. This review aims to discuss past experiences and understanding of diverse immunological targeting therapies for SLE and highlight future perspectives for the development of novel immunological therapies.

Refractory systemic lupus erythematosus with chylous effusion successfully treated with sirolimus: a case report and literature review

Chylous effusion is a rare manifestation of systemic lupus erythematosus (SLE). When it does occur in SLE, it is generally well treated with standard pharmacologic or surgical measures. We present a decade of management in a case of SLE with lung affliction and development of refractory bilateral chylous effusion and pulmonary arterial hypertension (PAH). In the first years, the patient was treated under a Sjogren syndrome diagnose. After few years, her respiratory condition worsened due to chylous effusion and PAH. Immunosuppression therapy (methylprednisolone) was reintroduced, and vasodilator therapy commenced. With this, her cardiac function remained stable, but respiratory function continuously worsened despite several therapy trials with different combinations of immunosuppressant (glucocorticoids, resochin, cyclophosphamide and mycophenolate mofetil). On top of pleural effusion worsening, the patient developed ascites and severe hypoalbuminaemia. Even though albumin loss was stabilized with monthly octreotide applications, the patient remained respiratory insufficient and in need of continuous oxygen therapy. At that point, we decided to introduce sirolimus on top of glucocorticoids and mycophenolate mofetil therapy. Her clinical status, radiological finding, and lung function gradually improved and she became respiratory sufficient at rest. The patient remains in our follow-up and has been stable on given therapy for over 3 years despite overcoming a severe COVID-19 pneumonia in 2021. This case adds to the body of evidence of sirolimus effectiveness in patients with refractory systemic lupus and is, to our best knowledge, the first case to report its successful application in a patient with SLE and refractory chylous effusion.

Promising Experimental Treatments for Lupus Nephritis: Key Talking Points and Potential Opportunities

Lupus nephritis (LN) is a frequent and serious complication of systemic lupus erythematosus (SLE), impairing patients' quality of life and significantly increasing mortality. Despite optimizing the use of conventional immunosuppressants and other biological drugs, its management remains unsatisfactory. This is mainly due to the heterogeneity of SLE, but also to insufficiently effective treatment regimens and clinical trial limitations (strict criteria, low number of patients included, and side effects). Most clinical trials of new biological therapies have failed to meet their primary endpoints in both general SLE and LN, with only two biological drugs (belimumab and anifrolumab) being approved by the Food and Drug Administration (FDA) for the treatment of SLE. Recently, several Phase II randomized controlled trials have evaluated the efficacy and safety of new biologics in LN, and some of them have demonstrated an improvement in clinical and laboratory measures. Multi-target therapies are also being successfully developed and encourage a belief that there will be an improvement in LN outcomes.

Rapamycin treatment induces tubular proteinuria: role of megalin-mediated protein reabsorption

Introduction: Rapamycin is an immunosuppressor that acts by inhibiting the serine/threonine kinase mechanistic target of rapamycin complex 1. Therapeutic use of rapamycin is limited by its adverse effects. Proteinuria is an important marker of kidney damage and a risk factor for kidney diseases progression and has been reported in patients and animal models treated with rapamycin. However, the mechanism underlying proteinuria induced by rapamycin is still an open matter. In this work, we investigated the effects of rapamycin on parameters of renal function and structure and on protein handling by proximal tubule epithelial cells (PTECs). Methods: Healthy BALB/c mice were treated with 1.5 mg/kg rapamycin by oral gavage for 1, 3, or 7 days. At the end of each treatment, the animals were kept in metabolic cages and renal function and structural parameters were analyzed. LLC-PK1 cell line was used as a model of PTECs to test specific effect of rapamycin. Results: Rapamycin treatment did not change parameters of glomerular structure and function. Conversely, there was a transient increase in 24-h proteinuria, urinary protein to creatinine ratio (UPCr), and albuminuria in the groups treated with rapamycin. In accordance with these findings, rapamycin treatment decreased albumin-fluorescein isothiocyanate uptake in the renal cortex. This effect was associated with reduced brush border expression and impaired subcellular distribution of megalin in PTECs. The effect of rapamycin seems to be specific for albumin endocytosis machinery because it did not modify renal sodium handling or (Na⁺+K⁺)ATPase activity in BALB/c mice and in the LLC-PK1 cell line. A positive Pearson correlation was found between megalin expression and albumin uptake while an inverse correlation was shown between albumin uptake and UPCr or 24-h proteinuria. Despite its effect on albumin handling in PTECs, rapamycin treatment did not induce tubular injury measured by interstitial space and collagen deposition. Conclusion: These findings suggest that proteinuria induced by rapamycin could have a tubular rather than a glomerular origin. This effect involves a specific change in protein endocytosis machinery. Our results open new perspectives on understanding the undesired effect of proteinuria generated by rapamycin.

Disturbance of neuron-microglia crosstalk mediated by GRP78 in Neuropsychiatric systemic lupus erythematosus mice

OBJECTIVES

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a serious phenotype of systemic lupus erythematosus (SLE). The disturbance of neuron-microglia crosstalk is recently revealed in many neuropsychiatric diseases but was not well studied in NPSLE. We found glucose regulatory protein 78 (GRP78), a marker of endoplasmic reticulum stress, was significantly increased in the cerebrospinal fluid (CSF) of our NPSLE cohort. We, therefore, investigated whether GRP78 can act as a mediator between the neuron-microglia crosstalk and is involved in the pathogenic process of NPSLE.

METHODS

Serum and CSF parameters were analyzed in 22 NPSLE patients and controls. Anti-DWEYS IgG was injected intravenously into mice to establish a model of NPSLE. Behavioral assessment, histopathological staining, RNA-seq analyses, and biochemical assays were performed to examine the neuro-immunological alterations in the mice. Rapamycin was intraperitoneally administered to define the therapeutic effect.

RESULTS

The level of GRP78 was elevated significantly in the CSF of the patients with NPSLE. An increase in GRP78 expression, accompanied by neuroinflammation and cognitive impairment, was also found in the brain tissues of the NPSLE model mice induced by anti-DWEYS IgG deposition on hippocampal neurons. In vitro experiments demonstrated that anti-DWEYS IgG could stimulate neurons to release GRP78, which activated microglia via TLR4/MyD88/NFκB pathway to produce more pro-inflammatory cytokines and promote migration and phagocytosis. Rapamycin ameliorated GRP78-inducing neuroinflammation and cognitive impairment in anti-DWEYS IgG-transferred mice.

CONCLUSION

GRP78 acts as a pathogenic factor in neuropsychiatric disorders via interfering neuron-microglia crosstalk. Rapamycin may be a promising therapeutic candidate for NPSLE.

Association between glomerular mTORC1 activation and crescents formation in lupus nephritis patients

OBJECTIVE

This study aims to explore the association between glomerular mammalian target of rapamycin complex 1 (mTORC1) pathway activation and crescents' degree in lupus nephritis (LN) patients.

METHODS

A total of 159 biopsy-proven LN patients were enrolled in this retrospective study. The clinical and pathological data of them were collected at the time of renal biopsy. mTORC1 pathway activation was measured by immunohistochemistry, expressed by the mean optical density (MOD) of p-RPS6 (ser235/236), and multiplexed immunofluorescence. The association of mTORC1 pathway activation with clinico-pathological features especially renal crescentic lesions, and the composite outcomes in LN patients was further analyzed.

RESULTS

mTORC1 pathway activation could be detected in the crescentic lesions and was positively correlated with the percentage of crescents (r = 0.479, P < 0.001) in LN patients. Subgroup analysis showed mTORC1 pathway was more activated in patients with cellular or fibrocellular crescentic lesions (P < 0.001), but not fibrous crescentic lesions (P = 0.270). The optimal cutoff value of the MOD of p-RPS6 (ser235/236) was 0.0111299 for predicting the presence of cellular-fibrocellular crescents in >7.39% of the glomeruli by the receiver operating characteristic curve. Cox regression survival analysis showed that mTORC1 pathway activation was an independent risk factor for the worse outcome (defined by composite endpoints of death, end-stage renal disease and a decrease of >30% in eGFR from baseline).

CONCLUSION

Activation of mTORC1 pathway was closely associated with the cellular-fibrocellular crescentic lesions and could be a prognostic marker in LN patients.

Rapamycin improves Graves' orbitopathy by suppressing CD4+ cytotoxic T lymphocytes

CD4+ cytotoxic T lymphocytes (CTLs) were recently implicated in immune-mediated inflammation and fibrosis progression of Graves' orbitopathy (GO). However, little is known about therapeutic targeting of CD4+ CTLs. Herein, we studied the effect of rapamycin, an approved mTOR complex 1 (mTORC1) inhibitor, in a GO mouse model, in vitro, and in patients with refractory GO. In the adenovirus-induced model, rapamycin significantly decreased the incidence of GO. This was accompanied by the reduction of both CD4+ CTLs and the reduction of orbital inflammation, adipogenesis, and fibrosis. CD4+ CTLs from patients with active GO showed upregulation of the mTOR pathway, while rapamycin decreased their proportions and cytotoxic function. Low-dose rapamycin treatment substantially improved diplopia and the clinical activity score in steroid-refractory patients with GO. Single-cell RNA-Seq revealed that eye motility improvement was closely related to suppression of inflammation and chemotaxis in CD4+ CTLs. In conclusion, rapamycin is a promising treatment for CD4+ CTL-mediated inflammation and fibrosis in GO.

A mechanistic target of rapamycin inhibitor, everolimus safely ameliorated lupus nephritis in a patient complicated with tuberous sclerosis

A 26-year-old woman with tuberous sclerosis complex (TSC) received outpatient treatment for the complication of systemic lupus erythematosus (SLE) at our hospital. She visited our hospital with a chief complaint of pitting oedema in bilateral lower legs for 3 days. The urinalysis showed massive proteinuria with a lot of white blood cell casts. The blood tests revealed hypoalbuminaemia, hypercholesterolaemia, hypocomplementaemia, and elevated anti-double-stranded DNA antibody titre. Renal biopsy was not performed because of multiple renal angiomyolipomas, which was one of the features of TSC. She was diagnosed with a nephrotic state due to lupus nephritis. Although she had a standard therapy with high-dose corticosteroid and mycophenolate mofetil and tacrolimus, complete remission had not been achieved leading to a steroid-dependent nephrotic syndrome. During the follow-up, the angiomyolipomas became larger and had a risk of rupture at the age of 29 years. Everolimus, a mechanistic target of rapamycin (mTOR) inhibitor, was started for the treatment of angiomyolipomas, and mycophenolate mofetil and tacrolimus were terminated instead. The activity of lupus nephritis was surprisingly ameliorated, and the amount of corticosteroid successfully tapered. Everolimus has been continued for 6 years without severe side effects. Accumulating evidence suggests that the activated mTOR pathway plays a key role in the pathogenesis of SLE. We reported the long-term efficacy and safety of everolimus for refractory SLE in a patient with TSC for the first time. This case suggests that everolimus can be a promising option for the treatment of lupus nephritis.

New insights in systemic lupus erythematosus: From regulatory T cells to CAR-T-cell strategies

Systemic lupus erythematous is a heterogeneous autoimmune disease with potentially multiorgan damage. Its complex etiopathogenesis involves genetic, environmental, and hormonal factors, leading to a loss of self-tolerance with autoantibody production and immune complex formation. Given the relevance of autoreactive B lymphocytes, several therapeutic approaches have been made targeting these cells. However, the disease remains incurable, reflecting an unmet need for effective strategies. Novel therapeutic concepts have been investigated to provide more specific and sustainable disease modification compared with continued immunosuppression. Autologous hematopoietic stem cell transplantation has already provided the proof-of-concept that immunodepletion can lead to durable treatment-free remissions, albeit with significant treatment-related toxicity. In the future, chimeric antigen receptor-T-cell therapies, for example, CD19 chimeric antigen receptor-T, may provide a more effective lymphodepletion and with less toxicity than autologous hematopoietic stem cell transplantation. An emerging field is to enhance immune tolerance by exploiting the suppressive capacities of regulatory T cells, which are dysfunctional in patients with systemic lupus erythematous, and thus resemble promising candidates for adoptive cell therapy. Different approaches have been developed in this area, from polyclonal to genetically engineered regulatory T cells. In this article, we discuss the current evidence and future directions of cellular therapies for the treatment of systemic lupus erythematous, including hematopoietic stem cell transplantation and advanced regulatory T-cell-based cellular therapies.

Clinical efficacy and safety of sirolimus in childhood-onset systemic lupus erythematosus in real world

To investigate the effectiveness and safety of sirolimus in childhood-onset systemic lupus erythematosus in a real world. This is a retrospective real world clinical study. All childhood-onset systemic lupus erythematosus patients treated with sirolimus in Children's Hospital of Hebei Province China were analyzed. They were treated with sirolimus and followed up regularly. The patients had systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score, levels of antidouble-stranded DNA antibody, complement components C3 and C4, 24-hour proteinuria and corticosteroid reduction were recorded at baseline and at 6, 12, and 18 months. Adverse events were also collected. Thirty-two patients were enrolled in the study. SLEDAI-2K were improved on all time-points (P < .05). Complement levels increased and the levels of antidouble-stranded DNA antibody decreased during treatment. The mean dose of prednisone tapered and achieved significant reduction after 12 months therapy (15.4 ± 5.8 mg/d to 4.8 ± 2.1 mg/d; P < .05). Sirolimus was well tolerated and only 5 patients (15.6%) experienced adverse events, all of which were classified as infections (2 bacterial infection and 3 viral infections). No deaths, severe infusion reactions, or hypersensitivity reactions were found. Sirolimus use was associated with a decrease in disease activity and ability to tolerate tapering of oral glucocorticoid dose with a favorable risk-benefit profile.

Novel and emerging treatment strategies for lupus nephritis

INTRODUCTION

Lupus nephritis (LN) is a key predictor for kidney failure and death in patients with systemic lupus erythematosus (SLE). While conventional immunosuppressive treatments have improved the outcome of LN, novel therapies continue to emerge. These new agents target specific immune-reactive cells (B cell repertoire or T lymphocytes) and crucial cytokines/signalling pathways in LN pathogenesis.

AREAS COVERED

New therapeutic approaches that target specific immune-reactive cells (B cell repertoire or T lymphocytes), crucial cytokines and their signalling pathways in LN pathogenesis.

EXPERT OPINION

Although earlier studies of rituximab fail to show benefit, a newer generation anti-CD20 biologic, obinutuzumab, is promising in LN. Inhibition of B-cell activating factor by belimumab confers superior renal response when added to the standard of care (SOC) regimens, leading to its recent approval for LN. Therapies targeting plasma cells (proteasome inhibitors, anti-CD38) in LN are being developed. A newer generation calcineurin inhibitor, voclosporin, when combined with SOC, results in better renal responses in LN. Other innovative strategies include targeting type I interferon, co-stimulatory signals, complement cascade (anti-C5b) and intracellular proliferation signals (e.g. mTOR, JAK1/2, BTK). While these novel agents improve the short-term renal responses without increased toxicities, long-term data on disease progression and safety remain to be established. Patient stratification by clinical phenotypes, biomarkers and molecular profiles helps enhance the efficacy and cost-effectiveness of novel therapies of LN.

Predicting the effect of sirolimus on disease activity in patients with systemic lupus erythematosus using machine learning

WHAT IS KNOWN AND OBJECTIVES

The present study aimed to predict the effect of sirolimus on disease activity in patients with systemic lupus erythematosus (SLE) using machine learning and to recommend appropriate sirolimus dosage regimen for patients with SLE.

METHODS

The E_max model was selected for machine learning, where the evaluation indicator was the change rate of systemic lupus erythematosus disease activity index from baseline value.

RESULTS

A total 103 patients with SLE were included for modelling, where the E_max , ET₅₀ were -53.9%, 1.53 months in the final model respectively, and the evaluation of the final model was good. Further simulation found that the follow-up time to achieve 25%, 50%, 75% and 80% (plateau) E_max of sirolimus effecting on disease activity in patients with SLE were 0.51, 1.53, 4.59 and 6.12 months, respectively. In addition, the sirolimus dosage was flexible and adjusted according to drug concentration, where the intersection of sirolimus concentration range included in this study was about 8-10 ng/ml.

WHAT IS NEW AND CONCLUSIONS

This study was the first time to predict the effect of sirolimus on disease activity in patients with SLE and in order to achieve better therapeutic effect maintaining a concentration of 8-10 ng/ml sirolimus for at least 6.12 months was necessary.

Neuropsychiatric lupus erythematosus: Focusing on autoantibodies

Patients with systemic lupus erythematosus (SLE) frequently suffer from nervous system complications, termed neuropsychiatric lupus erythematosus (NPLE). NPLE accounts for the poor prognosis of SLE. Correct attribution of NP events to SLE is the primary principle in managing NPLE. The vascular injuries and neuroinflammation are the fundamental neuropathologic changes in NPLE. Specific autoantibody-mediated central nerve system (CNS) damages distinguish NPLE from other CNS disorders. Though the central antibodies in NPLE are generally thought to be raised from the periphery immune system, they may be produced in the meninges and choroid plexus. On this basis, abnormal activation of microglia and disease-associated microglia (DAM) should be the common mechanisms of NPLE and other CNS disturbances. Improved understanding of both characteristic and sharing features of NPLE might yield further options for managing this disease.

Immunomodulatory and Antiaging Mechanisms of Resveratrol, Rapamycin, and Metformin: Focus on mTOR and AMPK Signaling Networks

Aging results from the progressive dysregulation of several molecular pathways and mTOR and AMPK signaling have been suggested to play a role in the complex changes in key biological networks involved in cellular senescence. Moreover, multiple factors, including poor nutritional balance, drive immunosenescence progression, one of the meaningful aspects of aging. Unsurprisingly, nutraceutical and pharmacological interventions could help maintain an optimal biological response by providing essential bioactive micronutrients required for the development, maintenance, and the expression of the immune response at all stages of life. In this regard, many studies have provided evidence of potential antiaging properties of resveratrol, as well as rapamycin and metformin. Indeed, in vitro and in vivo models have demonstrated for these molecules a number of positive effects associated with healthy aging. The current review focuses on the mechanisms of action of these three important compounds and their suggested use for the clinical treatment of immunosenescence and aging.

Autophagy in lupus nephritis: A delicate balance between regulation and disease

Autophagy is a highly regulated process wherein an unwanted cargo of damaged and dysfunctional cytoplasmic components is removed, delivered to lysosomes for degradation, and released back into the cytoplasm. Accumulating evidence suggests an important role of autophagy in the pathophysiology of systemic lupus erythematosus, with profound effects on both innate and adaptive immunity. Autophagy downregulation results in the inhibition of antigen presenting cells, reduced release of neutrophil extracellular traps and decreased activation of effector T and B cells, leading to reduced autoantibody production and attenuated type 1 interferon signaling. However, defective autophagy may accelerate the production of other inflammatory cytokines and reduce the clearance of apoptotic cells, promoting lupus development. In addition, autophagy dysfunction can concur to the pathogenesis of kidney injury in lupus nephritis. Autophagy is a pivotal mechanism to maintain podocyte integrity and endothelial cell survival. Several animal models have demonstrated that defective autophagy leads to podocyte injury and can promote an endothelial pro-inflammatory and atherogenic phenotype. Moreover, autophagy is a key homeostatic regulator of renal tubular cells, and recent evidence has pointed out that chronic autophagy deficiency may accelerate kidney fibrosis. Targeting autophagy may theoretically improve lupus nephritis outcomes, but novel, non-invasive methods to measure and monitor autophagic activity are urgently needed. In addition, the extent and timing of autophagy inhibition still require additional studies before clinical translation may be attempted. In this review, we will also discuss the effect of several clinically available drugs that can regulate the autophagic flux and their effect in lupus nephritis patients.

Successful treatment of sirolimus in a Chinese patient with refractory LN and APS: a case report

It has been reported that the mammalian target of rapamycin (mTOR) pathway is involved in the pathogenesis of systemic lupus erythematosus (SLE), and increasing evidence has shown the effect of mTOR-targeted therapies with sirolimus in SLE. The objective of this study was to report the successful treatment of sirolimus in a Chinese patient with refractory lupus nephritis (LN) and anti-phospholipid antibody syndrome (APS). A 44-year-old female with a previous diagnosis of autoimmune hemolytic anemia (AIHA) and APS secondary to SLE presented with lupus nephritis refractory to cyclophosphamide and mycophenolate. Renal biopsy met the criteria of WHO class III LN complicated by acute tubular injury and immunofluorescence confirmed the activation of the mTOR pathway. Treatment with the mTOR inhibitor sirolimus was initiated in this patient. Complete remission (CR) was achieved after 6 months, and flare-free remission was maintained for the next 3.5 years. The literature on the efficacy of sirolimus in patients with LN was reviewed. Although the available evidence is limited to retrospective studies with small sample sizes, sirolimus appeared to be efficacious in some patients with refractory LN. Well-designed clinical trials are warranted, and pathology-guided precision medicine might assist in guiding physicians’ treatment decisions.

Sirolimus versus tacrolimus for systemic lupus erythematosus treatment: results from a real-world CSTAR cohort study

OBJECTIVE

The effectiveness and safety of sirolimus for SLE treatment have been shown in some uncontrolled studies. However, a comparison of sirolimus with other classic immunosuppressants has not been reported. We conducted the study to compare the effectiveness and safety of sirolimus versus tacrolimus for SLE treatment.

METHODS

A real-world cohort study was conducted. Patients with clinically active SLE who were prescribed sirolimus or tacrolimus were enrolled. Propensity score matching was used to ensure equivalent disease conditions and background medications. SLE disease activity indices, serological parameters, steroid doses, modification of other immunosuppressants, renal effectiveness and adverse events were compared between the two groups at 3-month, 6-month, 9-month and 12-month follow-up visits.

RESULTS

Data from 52 patients in each of the sirolimus and tacrolimus groups were analysed. Indices regarding the effectiveness of sirolimus, including Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) scores, physician's global assessment (PhGA) scores, and proportion of patients with SLEDAI-2K reduction of ≥4 and PhGA increase of <0.3, were equivalent to those of tacrolimus at all follow-up timepoints (all p≥0.05). Greater improvements in complement levels were observed in the sirolimus group at 3 and 6 months. Higher percentages of patients with prednisone doses ≤7.5 mg/day were observed in the sirolimus group at all timepoints. Seventeen adverse events in the sirolimus group were recorded. None was severe or led to drug discontinuation.

CONCLUSIONS

Overall, sirolimus was as effective as tacrolimus in the treatment of SLE. Sirolimus had better effects on serological improvement and glucocorticoid tapering. Sirolimus was well tolerated in patients with SLE.

miR-20a Overexpression in Adipose-Derived Mesenchymal Stem Cells Promotes Therapeutic Efficacy in Murine Lupus Nephritis by Regulating Autophagy

Objective

Lupus nephritis is the most common and severe complication of systemic lupus erythematosus. The aim of our study was to investigate the efficacy of miR-20a overexpressing adipose-derived stem cell (ADSC) transplantation in murine lupus nephritis (LN) and explore potential molecular mechanisms.

Methods

Mouse ADSCs were transfected with a miR-20a lentiviral vector to obtain miR-20a overexpression ADSCs (miR-20a-ADSCs). We first observed the influence of miR-20a on ADSC viability and apoptosis in vitro. B6.MRL/lpr mice were administered ADSC/miR-20a-ADSC intravenously every week from age 30 to 33 weeks, and the lupus and normal control groups received PBS on the same schedule.

Results

miR-20a expression increased in miR-20a-ADSC-derived exosomes, and miR-20a overexpression promoted ADSC proliferation and inhibited apoptosis. Compared with ADSCs, miR-20a-ADSC treatment significantly improved serologic and histologic abnormalities, as evidenced by reduced serum creatinine, anti-dsDNA antibody, 24 h urine protein levels, nephritis scores, and C3/IgG deposits. Furthermore, miR-20a-ADSC treatment resulted in downregulated Akt, mTOR, and p62 expression and upregulated miR-20a, Beclin 1, and LC3 II/I expression compared with ADSC treatment. After treatment with miR-20a-ADSC, a significant increase in the number of autophagosomes within podocytes was observed, along with upregulated expression of podocin and nephrin, compared with the ADSC group.

Conclusions

miR-20a-ADSC transplantation prevents the development of lupus nephritis and significantly ameliorates already-established disease, and its mechanism is related to autophagy by targeting the miR-20a-regulated mTOR pathway.

Improvement of renal and non-renal SLE outcome measures on sirolimus therapy - A 21-year follow-up study of 73 patients

The safety, tolerance, and selected renal and non-renal outcome measures were evaluated in 73 SLE patients who received sirolimus therapy for more than 3 months in our institution over the past 21 years. In 12 patients who had lupus nephritis, proteinuria (p = 0.0287), hematuria (p = 0.0232), anti-DNA antibody levels (p = 0.0028) and steroid use were reduced (p = 0.0200). In the non-renal cohort of 61 patients, anti-DNA antibody levels (p = 0.0332) and steroid use were reduced (p = 0.0163). Both in the renal and non-renal cohorts, C3 (renal p = 0.0070; non-renal p = 0.0021) and C4 complement levels were increased (renal p = 0.0063; non-renal p = 0.0042) Adverse effects of mouth sores (2/73), headaches (1/73), and gastrointestinal discomfort were noted in a minority of patients (6/73). Sirolimus was only discontinued in two of 73 patients due to headache and recurrent infections, respectively. This study suggests that sirolimus is well tolerated and exerts long-term therapeutic efficacy in controlling renal and non-renal manifestations of SLE.