Comparative analysis of SGLT-2 expression in renal vasculitis and lupus nephritis

Progress of SGLT2 inhibitors in the treatment of common immune-related nephropathies

The immune system can lead to a variety of renal diseases through direct or indirect mechanisms. In immune-mediated nephropathy, though standardized treatment, there are still a small number of patients with further decline in renal function, which may even progress to renal failure; sodium-glucose cotransporter protein 2 (SLC5A2,SGLT2) inhibitors not only can significantly reduce blood glucose, but also have an additional protective effect on the kidneys and the heart; this review concludes the potential mechanism of the renal protective effect of SGLT2i and the new advances in the recent years in common immune-mediated nephropathies, which can provide new theoretical references to optimize the therapeutic strategy of common immune-mediated nephropathies.

EULAR recommendations for the management of systemic lupus erythematosus: 2023 update

OBJECTIVES

To update the EULAR recommendations for the management of systemic lupus erythematosus (SLE) based on emerging new evidence.

METHODS

An international Task Force formed the questions for the systematic literature reviews (January 2018-December 2022), followed by formulation and finalisation of the statements after a series of meetings. A predefined voting process was applied to each overarching principle and recommendation. Levels of evidence and strengths of recommendation were assigned, and participants finally provided their level of agreement with each item.

RESULTS

The Task Force agreed on 5 overarching principles and 13 recommendations, concerning the use of hydroxychloroquine (HCQ), glucocorticoids (GC), immunosuppressive drugs (ISDs) (including methotrexate, mycophenolate, azathioprine, cyclophosphamide (CYC)), calcineurin inhibitors (CNIs, cyclosporine, tacrolimus, voclosporin) and biologics (belimumab, anifrolumab, rituximab). Advice is also provided on treatment strategies and targets of therapy, assessment of response, combination and sequential therapies, and tapering of therapy. HCQ is recommended for all patients with lupus at a target dose 5 mg/kg real body weight/day, considering the individual's risk for flares and retinal toxicity. GC are used as 'bridging therapy' during periods of disease activity; for maintenance treatment, they should be minimised to equal or less than 5 mg/day (prednisone equivalent) and, when possible, withdrawn. Prompt initiation of ISDs (methotrexate, azathioprine, mycophenolate) and/or biological agents (anifrolumab, belimumab) should be considered to control the disease and facilitate GC tapering/discontinuation. CYC and rituximab should be considered in organ-threatening and refractory disease, respectively. For active lupus nephritis, GC, mycophenolate or low-dose intravenous CYC are recommended as anchor drugs, and add-on therapy with belimumab or CNIs (voclosporin or tacrolimus) should be considered. Updated specific recommendations are also provided for cutaneous, neuropsychiatric and haematological disease, SLE-associated antiphospholipid syndrome, kidney protection, as well as preventative measures for infections, osteoporosis, cardiovascular disease.

CONCLUSION

The updated recommendations provide consensus guidance on the management of SLE, combining evidence and expert opinion.

A Transcriptome Array-Based Approach to Link SGLT-2 and Intrarenal Complement C5 Synthesis in Diabetic Nephropathy

Diabetic nephropathy is a common microvascular complication of diabetes mellitus. It is characterized by progressive chronic kidney disease (CKD) with decline of kidney function by hyperfiltration. On a mechanistic level, activation of the complement system has been implicated in the pathogenesis of diabetic nephropathy. Therefore, here we pursued a transcriptome array-based approach to link intrarenal SGLT-2 and the synthesis of distinct complement components in diabetic nephropathy. Publicly available datasets for SLC5A2 (encoding SGLT-2) and complement system components were extracted specifically from microdissected tubulointerstitial (healthy controls: n = 31, diabetic nephropathy: n = 17) and glomerular compartments (healthy controls: n = 21, diabetic nephropathy: n = 12). First, we compared tubulointerstitial and glomerular log2SLC5A2 mRNA expression levels and confirmed a predominant synthesis within the tubulointerstitial compartment. Among various complement components and receptors, the only significant finding was a positive association between SLC5A2 and the tubulointerstitial synthesis of the complement component C5 in diabetic nephropathy (p = 0.0109). Finally, intrarenal expression of SLC5A2 was associated predominantly with pathways involved in metabolic processes. Interestingly, intrarenal complement C5 synthesis was also associated with enrichment of metabolic signaling pathways, overlapping with SLC5A2 for "metabolism" and "biological oxidations". These observations could be of relevance in the pathogenesis of diabetic nephropathy and implicate a mechanistic link between SGLT-2 and intrarenal complement synthesis.

Management of systemic lupus erythematosus: A new scenario

The introduction of targeted biological agents in systemic lupus erythematosus (SLE) has created a momentum for improving overall disease management and patients' prognosis. To achieve this, a comprehensive strategy is required spanning the entire patient journey from diagnosis to prevention and management of late complications and comorbidities. In this review, we focus on four aspects that are closely linked to SLE prognosis, namely early disease recognition and treatment initiation, reduction of the cumulative glucocorticoid exposure, attainment of well-defined targets of remission and low disease activity, prevention of flares and, kidney-protective strategies with non-immune-directed agents. We review the recent literature related to these topics in conjunction with the existing treatment recommendations, highlighting areas of uncertainty and providing guidance towards facilitating the care of SLE patients.

SGLT2 inhibitors alleviated podocyte damage in lupus nephritis by decreasing inflammation and enhancing autophagy

OBJECTIVES

The protective role of sodium glucose cotransporter 2 (SGLT2) inhibitors in renal outcomes has been revealed by large cardiovascular outcome trials among patients with type 2 diabetes. However, the effect of SGLT2 inhibitors on lupus nephritis (LN) and its underlying mechanisms remain unknown.

METHODS

We applied empagliflozin treatment to lupus-prone MRL/lpr mice to explore the renal protective potential of SGLT2 inhibitors. An SGLT2 knockout monoclonal podocyte cell line was generated using the CRISPR/Cas9 system to examine the cellular and molecular mechanisms.

RESULTS

In MRL/lpr mice treated with empagliflozin, the levels of mouse anti-dsDNA IgG-specific antibodies, serum creatinine and proteinuria were markedly decreased. For renal pathology assessment, both the glomerular and tubulointerstitial damages were lessened by administration of empagliflozin. The levels of SGLT2 expression were increased and colocalised with decreased synaptopodin in the renal biopsy samples from patients with LN and MRL/lpr mice with nephritis. The SGLT2 inhibitor empagliflozin could alleviated podocyte injury by attenuating inflammation and enhanced autophagy by reducing mTORC1 activity. Nine patients with LN treated with SGLT2 inhibitors with more than 2 months of follow-up showed that the use of SGLT2 inhibitors was associated with a significant decrease in proteinuria from 29.6% to 96.3%. Moreover, the estimated glomerular filtration rate (eGFR) was relatively stable during the treatment with SGLT2 inhibitors.

CONCLUSION

This study confirmed the renoprotective effect of SGLT2 inhibitors in lupus mice, providing more evidence for non-immunosuppressive therapies to improve renal function in classic autoimmune kidney diseases such as LN.

Lupus Nephritis: New and Emerging Biologic and Targeted Therapies

Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE), a polyclonal systemic autoimmunity directed against nuclear and other self-antigens. SLE/LN affects mostly females during childbearing age, which puts them at risk for the progression of chronic kidney disease (CKD), cardiovascular disease, and pregnancy complications. The current management of LN involves the use of drugs with significant toxicities, and despite many attempts at novel drug interventions, the overall treatment efficacy has remained low. In this article, we discuss recent drug approvals and the upcoming pipeline of novel medications tested in clinical trials to improve effectiveness in terms of LN disease activity, LN relapse, and progression of LN-related CKD. In this context, we discuss (1) drugs with the potential to achieve these treatment goals by modulating SLE activity as the driving force for LN (e.g., belimumab, obinutuzumab, anifrolumab, and others); (2) drugs with SLE-non specific renoprotective effects by targeting non-immune mechanisms of LN progression (dapagliflozin, empagliflozin); and (3) drugs with dual immunosuppressive and antiproteinuric effects (voclosporin). Increasing the number of possible drug options will help to improve the management of LN in terms of efficacy and safety, and enable a more personalized treatment approach.

Safety and efficacy of the SGLT2 inhibitor dapagliflozin in patients with systemic lupus erythematosus: a phase I/II trial

OBJECTIVE

Sodium-glucose cotransporter-2 inhibitors have been identified profound renal/cardiac protective effects in different diseases. Here, we assessed the safety and efficacy of dapagliflozin among adult patients with systemic lupus erythematosus (SLE).

METHODS

We conducted a single-arm, open-label, investigator-initiated phase I/II trial of dapagliflozin in Chinese patients with SLE with/without lupus nephritis (LN). Patients received oral dapagliflozin at a daily dose of 10 mg added to the standard of care for 6 months. The primary end point was the safety profile. The secondary efficacy end points were composite assessments of disease activity.

RESULTS

A total of 38 eligible patients were enrolled. Overall, 19 (50%) adverse events (AEs) were recorded, including 8 (21%) AEs leading to drug discontinuation, of which 4 (10.5%) were attributed to dapagliflozin. Two serious AEs (one of major lupus flare and one of fungal pneumonia) were recorded. Lower urinary tract infection was observed in one (2.63%) patient. The secondary end points revealed no improvement of SLE Disease Activity Index scores or proteinuria (among 17 patients with LN); the cumulative lupus flare rate was 18%, and a reduction of ~30% in the prednisone dose was captured. Net changes in body mass index (-0.50 kg/m2), systolic blood pressure (-3.94 mm Hg) and haemoglobin levels (+8.26 g/L) were detected. The overall estimated glomerular filtration rate (eGFR) was stable, and there was an improvement in the eGFR slope among patients with LN with a baseline eGFR <90 mL/min/1.73 m2.

CONCLUSION

Dapagliflozin had an acceptable safety profile in adult patients with SLE. Its possible renal/cardiac protective effects and long-term safety issues in patients with SLE, patients with LN in particular, call for further exploration.

TRIAL REGISTRATION NUMBER

ChiCTR1800015030.