Target Therapy in SLE

Omega-3 fatty acids: Current insights into mechanisms of action in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is one of the autoimmune diseases characterized by the lack of self-tolerance and the formation of immune complexes and nuclear autoantigens resulting in inflammation in multiple organs. Nowadays, the major aim of SLE therapy is the control of disease activity. However, the biological heterogeneity between patients and the absence of safe and specific targeted treatments complicate the lupus management. Therefore, the potential prophylactic effects of natural therapy considering the potential side effects of classical pharmacology, also the role of diet therapy in decreasing co-morbidities and improving quality of life in SLE patients could be a promising approach to SLE disease. Omega-3 polyunsaturated fatty acids (omega-3 PUFAs) are one of the agents that are considered for their preventive and therapeutic properties in disease activity of SLE and the related complications. The intake of omega-3 PUFAs likely has a direct relationship with improvements in inflammatory, cardiovascular, depressive, and neuromotor symptoms of the patients. The current review summarizes clinical and preclinical studies with comprehensive insights into the mechanisms of action of omega-3 fatty acids (omega-3 FAs) in Systemic Lupus Erythematosus to provide an update on the negative and positive aspects of the intake of omega-3 FAs in SLE patients.

Identification of polo-like kinase 1 as a therapeutic target in murine lupus

Introduction

The signalling cascades that contribute to lupus pathogenesis are incompletely understood. We address this by using an unbiased activity‐based kinome screen of murine lupus.

Methods

An unbiased activity‐based kinome screen (ABKS) of 196 kinases was applied to two genetically different murine lupus strains. Systemic and renal lupus were evaluated following in vivo PLK1blockade. The upstream regulators and downstream targets of PLK1 were also interrogated.

Results

Multiple signalling cascades were noted to be more active in murine lupus spleens, including PLK1. In vivo administration of a PLK1‐specific inhibitor ameliorated splenomegaly, anti‐dsDNA antibody production, proteinuria, BUN and renal pathology in MRL.lpr mice (P < 0.05). Serum IL‐6, IL‐17 and kidney injury molecule 1 (KIM‐1) were significantly decreased after PLK1 inhibition. PLK1 inhibition reduced germinal centre and marginal zone B cells in the spleen, but changes in T cells were not significant. In vitro, splenocytes were treated with anti‐mouse CD40 Ab or F(ab’)2 fragment anti‐mouse IgM. After 24‐h stimulation, IL‐6 secretion was significantly reduced upon PLK1 blockade, whereas IL‐10 production was significantly increased. The phosphorylation of mTOR was assessed in splenocyte subsets, which revealed a significant change in myeloid cells. PLK1 blockade reduced phosphorylation associated with mTOR signalling, while Aurora‐A emerged as a potential upstream regulator of PLK1.

Conclusion

The Aurora‐A → PLK1 → mTOR signalling axis may be central in lupus pathogenesis, and emerges as a potential therapeutic target.

Predicting lupus low disease activity state and remission in SLE: novel insights

Introduction:Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with extreme heterogeneity, which sometimes may be life-threatening. Principles of treat to target (T2T) in SLE were put forward more recently, leading to better long-term survival and reduced damage accrual.Areas covered: Lupus low disease activity state (LLDAS) and remission are currently the most widely accepted principal goals of SLE-T2T recommendations. In this article, we will deliver the novel insights into the definitions of LLDAS/remission, attainability, and, most importantly, clinical predictors of LLDAS and remission in SLE.Expert opinion: Since the release of the LLDAS and the framework on definitions of remission in SLE, there has been much evidence of a correlation between target attainment or maintenance and better prognosis. In the meantime, researchers are searching for predictors of target attainment. Noteworthy, prospective randomized trials are lacking worldwide to verify the benefits of T2T in various aspects of SLE. The most essential issue is that the optimal definition of the therapeutic target for SLE remains controversial, particularly regarding the maintenance dose of prednisone, the need for immunosuppressive withdrawal, and the requirement for serologic conversion. How to implement T2T principles in clinical practice also needs further investigation.

Impact of the longitudinal quantitative assessment of juvenile systemic lupus erythematosus severity on the disease outcome

OBJECTIVES

This study on juvenile SLE patients aimed to evaluate retrospectively the impact of a tertiary center's management policy of the disease severity on its long-term progression and cumulative damage development as well as provision of quality-driven medical care (QmC).

METHODS

Disease activity was assessed by the Physician Global Assessment and SLEDAI-2K, flares by SELENA/SLEDAI, and damage by the pediatric SLICC/DI at diagnosis, 6 months post-diagnosis, and annually thereafter. At the same time, QmC was evaluated by relevant indices and quality of life was captured by the Greek version of the General Health Questionnaire only at the last visit.

RESULTS

A total of 35 patients (25/35 females) aged at diagnosis 5.5-15.16 years (median 11.83) with a median lag time to diagnosis 1.8 months had a follow-up of 5 (35/35) and 10 years (13/35), respectively. The predominant baseline manifestations were consistent with those previously reported. Out of 35 patients, 24 (68.5%) were clinically inactive at year 5, and 5/13 (38%) at year 10. All patients received immunosuppressives and 7/35 biologics in addition. At the end of their follow-up, damage was found in 9/35 patients, but none of them had a neuropsychiatric disorder. Over the study, 28/35 patients were compliant with the QmC recommendations.

CONCLUSIONS

An early diagnosis combined with a longitudinal quantitative assessment of the disease activity and severity contributes to the continuous evaluation of the disease state. They are the key determinants for the selection of an early, targeted, and personalized management; they restrict the cumulative damage development and contribute to an optimal outcome. Key Points • Juvenile SLE has a heavier introductory profile than in adults and an unpredictable trajectory. • The application of contemporary metric tools for assessing the disease state leads to an objective assessment and regimen selection. • An early diagnosis combined with longitudinal quantitative assessment is a key determinant for an optimal management and a minimal damage development.

Frequencies and predictors of the Lupus Low Disease Activity State and remission in treatment-naïve patients with systemic lupus erythematosus

Objectives

To evaluate the attainability of Lupus Low Disease Activity State (LLDAS) and definitions of remission in SLE (DORIS) in a treatment-naïve cohort of SLE.

Methods

LLDAS5 was defined as LLDAS with a prednisone dose ≤5 mg/day. There were four definitions in DORIS: clinical remission on treatment (RONT), complete RONT, clinical remission off treatment (ROFT) and complete ROFT. The treatment-naïve patients from Peking University First Hospital SLE cohort were enrolled. The time to each state and their annual cumulative probabilities were estimated. The frequencies of patients who achieved each component of LLDAS or DORIS during follow-up were determined. The predictors of time to each state were identified.

Results

A total of 218 patients were included, with a median follow-up of 4.48 years. Respectively, 190 (87.2%), 160 (73.4%), 148 (67.9%), 94 (43.1%), 23 (10.6%) and 18 (8.3%) patients achieved LLDAS, LLDAS5, clinical RONT, complete RONT, clinical ROFT and complete ROFT. The median time to LLDAS, LLDAS5, clinical RONT and complete RONT were 1.4, 2.3, 2.6 and 4.7 years, respectively. Positive anti-dsDNA, RP and anaemia were significantly associated with prolonged time to LLDAS, LLDAS5 or clinical RONT.

Conclusion

Our data confirmed that LLDAS is an attainable early treatment target for SLE. Though with more difficulty, RONT can be achieved in two-thirds of our patients. ROFT may not be an ideal treatment target at present as it is only attained in few patients.

Understanding the dynamics of hydroxychloroquine blood levels in lupus nephritis

Objectives

It is unknown if hydroxychloroquine blood level dynamics impact flare rates in lupus nephritis patients. We prospectively evaluated hydroxychloroquine levels to determine which blood-based patterns are more associated with disease activity.

Methods

In total, 82 lupus nephritis patients under a prescribed hydroxychloroquine dose of 4–5.5 mg/kg actual body weight (maximum 400 mg/day) for ≥3 months were evaluated at baseline and 7 months. Hydroxychloroquine blood levels were determined by liquid chromatography-tandem mass spectrometry. Flare was defined as increase ≥3 in the Systemic Lupus Erythematosus Disease Activity Index 2000 score and/or a change or increase in therapy.

Results

Overall, 9/82(11%) patients had flares during follow-up and had lower baseline hydroxychloroquine blood levels than those without flares (220.4 (53.5–1471.1) vs. 1006.3 (53.5–2137.8) ng/ml, p = 0.013). The hydroxychloroquine blood level cut-off that best predicted flares was 613.5 ng/ml (odds ratio = 8.67, 95% confidence interval: 1.66–45.18, p = 0.006). For 77 (94%) patients, the 7-month hydroxychloroquine level dynamics was evaluated and revealed: 59/77 (77%) had a persistent pattern of adequate (41/77(53%)) or fluctuating (18/77 (23%)) levels, with a low and comparable risk of flares (2/41 (5%) vs. 1/18 (5%), p = 1.000). The remaining group had persistent low levels (18/77 (23%)) and their flare frequency was significantly higher than the adequate group (5/18 (28%) vs. 2/41 (5%), p = 0.023). The frequencies of adequate/inadequate hydroxychloroquine blood levels in patients were comparable at baseline and 7 months (McNemar’s test, p = 0.480).

Conclusion

We provide novel evidence that hydroxychloroquine blood-level patterns (persistently low, adequate, or intermittent) have distinct impacts on flare rates in lupus nephritis patients. These findings reinforce the need of routine hydroxychloroquine measurements to maintain the appropriate blood levels.

Molecular mechanism of celastrol in the treatment of systemic lupus erythematosus based on network pharmacology and molecular docking technology

BACKGROUND

Network pharmacology uses bioinformatics to broaden our understanding of drug actions and thereby advance drug discovery. Here we apply network pharmacology to generate testable hypotheses about the multi-target mechanism of celastrol against systemic lupus erythematosus (SLE).

METHODS

We reconstructed drug-target pathways and networks to predict the likely protein targets of celastrol and the main interactions between those targets and the drug. Then we validated our predictions of candidate targets by performing docking studies with celastrol.

RESULTS

The results suggest that celastrol acts against SLE by regulating the function of several signaling proteins, such as interleukin 10, tumor necrosis factor, and matrix metalloprotein 9, which regulate signaling pathways involving mitogen-activated protein kinase and tumor necrosis factor as well as apoptosis pathways. Celastrol is predicted to affect networks involved mainly in cytokine activity, cytokine receptor binding, receptor ligand activity, receptor regulator activity, and cofactor binding. Molecular docking analysis showed that hydrogen bonding and π-π stacking were the main forms of interaction.

CONCLUSIONS

This network pharmacology strategy may be useful for discovery of multi-target drugs against complex diseases, specifically, it provides protein targets associated with SLE that may be further tested for therapeutic potential by celastrol.

P2X7 receptor: A potential therapeutic target for autoimmune diseases

P2X7 receptor (P2X7R), a distinct ligand-gated ion channel, is a member of purinergic type 2 receptor family with ubiquitous expression in human body. Previous studies have revealed a pivotal role of P2X7R in innate and adaptive immunity. Once activated, it will meditate some vital cascaded responses including the assembly of nucleotide-binding domain (NOD) like receptor protein 3 (NLRP3) inflammasome, non-classical secretion of IL-1β, modulation of cytokine-independent pathways in inflammation such as P2X7R- transglutaminase-2 (TG2) and P2X7R-cathepsin pathway, activation and regulation of T cells, etc. In fact, above responses have been identified to be involved in the development of autoimmunity, specifically, the NLRP3 inflammasome could promote inflammation in massive autoimmune diseases and TG2, as well as cathepsin may contribute to joint destruction and degeneration in inflammatory arthritis. Recently, numerous evidences further suggested the significance of P2X7R in the pathogenesis of autoimmune diseases, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), inflammatory bowel disease (IBD), multiple sclerosis (MS), etc. In this review, we will succinctly discuss the biological characteristics and summarize the recent progress of the involvement of P2X7R in the development and pathogenesis of autoimmune diseases, as well as its clinical implications and therapeutic potential.

Refractory lupus nephritis: When, why and how to treat

Refractory lupus nephritis indicates an inadequate response to lupus nephritis therapy. It implies persisting or worsening disease activity despite therapy, but the definition is complicated by the parameters of response, proteinuria and renal function, that do not discriminate clearly between activity and irreversible damage. Understanding the causes of refractory disease and developing treatment strategies is important because these patients are more likely to develop poor outcomes, especially end stage renal disease. This review explores current concepts and definitions of refractory disease and summarises treatment approaches that have been used in observational cohort studies and case series. We highlight the importance of optimising adherence to the prescribed immunosuppressive and supportive measures and avoidance of diagnostic delay. Treatment options include higher dose glucocorticoid, switching between cyclophosphamide and mycophenolate acid derivates, or addition of rituximab, the latter potentially in combination with belimumab. Less evidence supports extracorporeal treatment (plasma exchange or immunoadsorption), calcineurin inhibitors (cyclosporine A or tacrolimus), intravenous immunoglobulin and stem cell transplantation. Improvements in understanding what refractory disease is and how definitions can be integrated into treatment pathways has the potential to enhance lupus nephritis outcomes.