Lupus nephropathy beyond immunosuppression: Searching for nephro and cardioprotection

[Update on lupus nephritis]

In addition to the butterfly rash, lupus nephritis is the most specific manifestation of systemic lupus erythematosus (SLE). The perspective on this organ manifestation has fundamentally changed as well as the manifestation of SLE itself 40 years after the first multicenter clinical study on lupus nephritis. Even if there is a faint glimpse of hope of a cure, there is still the fight against the problem of nonresponders and also the progressive loss of organ function. This update gives an overview of the current importance of lupus nephritis in the context of the whole SLE disease, of the special features and on the options provided by the new diagnostic and therapeutic developments.

Systemic lupus erythematosus

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

Sodium-glucose cotransporter 2 inhibitors: are they ready for prime time in the management of lupus nephritis?

PURPOSE OF REVIEW

Lupus nephritis is a common complication of systemic lupus erythematosus and is associated with significant morbidity and mortality. The utility of sodium-glucose cotransporter 2 (SGLT2) inhibitors in the management of lupus nephritis is currently uncertain. Here, we summarize the rationale for their use among patient with lupus nephritis.

RECENT FINDINGS

SGLT2 inhibitors were initially developed as antihyperglycemic agents. They have since been shown to have additional, profound effects to slow the progression of chronic kidney disease and lessen the long-term risks of cardiovascular disease in large clinic trials of patients with chronic kidney disease, with and without diabetes, as well as in patients with and without proteinuria. Patients with recent exposure to immunosuppression were excluded from these trials due to concern for risk of infection. In the few, small trials of patients with lupus nephritis, SGLT2 inhibitors were found to be well tolerated. They have been shown to reduce proteinuria and to have modest beneficial effects on blood pressure and BMI among patients with lupus nephritis. They have not been shown to influence disease activity.

SUMMARY

SGLT2 inhibitors may have a role in mitigating the chronic renal and cardiovascular effects of lupus nephritis. They should be introduced after kidney function has been stabilized with appropriate immunosuppression, in conjunction with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. They currently have no role in active disease.

The Inflammatory Profile Orchestrated by Inducible Nitric Oxide Synthase in Systemic Lupus Erythematosus

(1) Background: The pathogenesis of systemic lupus erythematosus (SLE) involves complicated and multifactorial interactions. Inducible nitric oxide synthase overactivation (iNOS or NOS2) could be involved in SLE pathogenesis and progression. This study explored the relationship between NOS2-associated inflammation profiles and SLE phenotypes. (2) Methods: We developed a prospective, case control study that included a group of 86 SLE subjects, a group of 73 subjects with lupus nephritis, and a control group of 60 people. Laboratory determinations included serum C reactive protein (CRP-mg/L), enzymatic activity of NOS2 (U/L), serum levels of inducible factors of hypoxia 1 and 2 (HIF1a-ng/mL, HIF2a-ng/mL), vascular endothelial growth factor VEGF (pg/mL), matrix metalloproteinases 2 and 9 (MMP-2, MMP-9-ng/mL), thrombospondin 1 (TSP-1-ng/mL), and soluble receptor of VEGF (sVEGFR-ng/mL). (3) Results: CRP, NOS2, HIF-1a, HIF-2a, VEGF, MMP-2, and MMP-9 were significantly increased, while TSP-1 and sVEGFR were decreased in the SLE and lupus nephritis groups compared with the control group. The variations in these biomarkers were strongly associated with the decrease in eGFR and increase in albuminuria. (4) Conclusions: The inflammatory phenotype of SLE patients, with or without LN, is defined by NOS2 and hypoxia over-expression, angiogenesis stimulation, and inactivation of factors that induce resolution of inflammation in relation with eGFR decline.