Diagnostic value of urinary monocyte chemoattractant protein-1 in evaluating the activity of lupus nephritis: a meta-analysis

Kidney transplantation in Lupus Nephritis: a comprehensive review of challenges and strategies

PURPOSE OF REVIEW: Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE), significantly impacting patient outcomes. Despite advances in immunosuppressive therapies, many patients progress to end-stage renal disease (ESRD), and kidney transplantation becomes essential for improving survival. However, the unique characteristics of autoimmune diseases make the timing of kidney transplantation and post-transplant management challenging. This review evaluates authoritative guidelines and recent studies to identify optimal timing for kidney transplantation and effective pre- and post-transplant management measures for patients with LN. RECENT FINDINGS: Advancements in immunosuppressive therapies, including calcineurin inhibitors, Voclosporin, and biologic agents such as belimumab, have significantly improved LN management. Emerging biomarkers, such as urinary MCP-1 and BAFF, offer promising tools for monitoring LN activity and predicting recurrence risk post-transplantation. Current guidelines emphasize the importance of achieving disease quiescence before transplantation, while new evidence supports the benefits of preemptive transplantation and personalized immunosuppressive regimens in improving patient and graft survival. This review highlights the latest evidence and strategies for optimizing kidney transplantation outcomes in LN patients, focusing on timing, immunosuppression, and disease monitoring.

Lupus nephritis: Biomarkers

Lupus nephritis (LN) or renal involvement of systemic lupus erythematosus (SLE), is a common manifestation occurring in at least 50 % of SLE patients. LN remains a significant source of morbidity, often leading to progressive renal dysfunction and is a major cause of death in SLE. Despite these challenges, advances in the understanding of the pathogenesis and genetic underpinnings of LN have led to a commendable expansion in available treatments over the past decade. This chapter provides a foundation for the understanding LN pathogenesis, diagnosis, and epidemiology, and guides the reader through recent advances in biomarkers, genetic susceptibility of this intricate condition.

Investigating the value of urinary biomarkers in relation to lupus nephritis histopathology: present insights and future prospects

Lupus nephritis (LN), a leading cause of death in Systemic Lupus Erythematosus (SLE) patients, presents significant diagnostic and prognostic challenges. Although renal pathology offers critical insights regarding the diagnosis, classification, and therapy for LN, its clinical utility is constrained by the invasive nature and limited reproducibility of renal biopsies. Moreover, the continuous monitoring of renal pathological changes through repeated biopsies is impractical. Consequently, there is a growing interest in exploring urine as a non-invasive, easily accessible, and dynamic "liquid biopsy" alternative to guide clinical management. This paper examines novel urinary biomarkers from a renal pathology perspective, encompassing cellular components, cytokines, adhesion molecules, auto-antibodies, soluble leukocyte markers, light chain fragments, proteins, small-molecule peptides, metabolomics, urinary exosomes, and ribonucleic acids. We also discuss the application of combined models comprising multiple biomarkers in assessing lupus activity. These innovative biomarkers and models offer insights into LN disease activity, acute and chronic renal indices, fibrosis, thrombotic microangiopathy, podocyte injury, and other pathological changes, potentially improving the diagnosis, management, and prognosis of LN. These urinary biomarkers or combined models may serve as viable alternatives to traditional renal pathology, potentially revolutionizing the method for future LN diagnosis and observation.

Non-Invasive Biomarkers for Diagnosis, Risk Prediction, and Therapy Guidance of Glomerular Kidney Diseases: A Comprehensive Review

Effective management of glomerular kidney disease, one of the main categories of chronic kidney disease (CKD), requires accurate diagnosis, prognosis of progression, assessment of therapeutic efficacy, and, ideally, prediction of drug response. Multiple biomarkers and algorithms for the assessment of specific aspects of glomerular diseases have been reported in the literature. Though, the vast majority of these have not been implemented in clinical practice or are not available on a global scale due to limited access, missing medical infrastructure, or economical as well as political reasons. The aim of this review is to compile all currently available information on the diagnostic, prognostic, and predictive biomarkers currently available for the management of glomerular diseases, and provide guidance on the application of these biomarkers. As a result of the compiled evidence for the different biomarkers available, we present a decision tree for a non-invasive, biomarker-guided diagnostic path. The data currently available demonstrate that for the large majority of patients with glomerular diseases, valid biomarkers are available. However, despite the obvious disadvantages of kidney biopsy, being invasive and not applicable for monitoring, especially in the context of rare CKD etiologies, kidney biopsy still cannot be replaced by non-invasive strategies.

Lupus Nephritis Biomarkers: A Critical Review

Lupus nephritis (LN), a major complication in individuals diagnosed with systemic lupus erythematosus, substantially increases morbidity and mortality. Despite marked improvements in the survival of patients with severe LN over the past 50 years, complete clinical remission after immunosuppressive therapy is achieved in only half of the patients. Therefore, timely detection of LN is vital for initiating prompt therapeutic interventions and improving patient outcomes. Biomarkers have emerged as valuable tools for LN detection and monitoring; however, the complex role of these biomarkers in LN pathogenesis remains unclear. Renal biopsy remains the gold standard for the identification of the histological phenotypes of LN and guides disease management. However, the molecular pathophysiology of specific renal lesions remains poorly understood. In this review, we provide a critical, up-to-date overview of the latest developments in the field of LN biomarkers.

Biomarkers for systemic lupus erythematosus - a focus on organ damage

INTRODUCTION

Systemic lupus erythematosus (SLE) is complex autoimmune disease with heterogenous manifestations, unpredictable disease course and response to treatment. One of the critical needs in SLE management is the identification of reliable biomarkers that can aid in early diagnosis, accurate monitoring of disease activity, and assessment of treatment response.

AREAS COVERED

In the current review, we focus on the commonly affected organs (skin, kidney, and nervous system) in SLE to summarize the emerging biomarkers that show promise in disease diagnosis, monitoring and treatment response assessment. The subtitles within each organ domain were determined based on the most relevant and promising biomarkers for that specific organ damage.

EXPERT OPINION

Biomarkers have the potential to significantly benefit the management of SLE by aiding in diagnosis, disease activity monitoring, prognosis, and treatment response assessment. However, despite decades of research, none has been validated and implemented for routine clinical use. Novel biomarkers could lead to the development of precision medicine for SLE, guide personalized treatment, and improve patient outcomes. Challenges in biomarker research in SLE include defining clear and clinically relevant questions, accounting for the heterogeneity of SLE, and confirming initial findings in larger, multi-center, multi-ethnic, independent cohorts that reflect real-world clinical scenarios.

The first-year course of urine MCP-1 and its association with response to treatment and long-term kidney prognosis in lupus nephritis

OBJECTIVES

The present study aims to assess the course of uMCP-1 and its association with response to therapy and long-term kidney function in a prospective cohort of adults who received a kidney biopsy for suspicion of active lupus nephritis (LN).

METHODS

Subjects were segregated into a histologically active LN group and a histologically chronic LN group. Both groups were followed for > = 36 months and urine were collected at flare, 3, 6, and 12 months of follow-up. The association between the course of uMCP-1, response to treatment, and progression to 30% loss of the eGFR was evaluated by linear mixed models for repeated measures.

RESULTS

A kidney biopsy was performed on 125 subjects. In 114, the report was consistent with histologically active LN; in 11, with histologically chronic LN. Urine MCP-1 levels were significantly higher in the active LN than in the chronic LN group. Urine MCP-1 levels correlated with the histological findings of cellular crescents, endocapillary hypercellularity, interstitial inflammation, glomerular sclerosis, interstitial fibrosis, and tubular atrophy. The mean estimates of uMCP-1 at flare were higher in the non-response group than in the complete response group, and decreased in the complete/partial response groups by the third month, while they remained elevated in the non-response group. The mean estimates for uMCP-1 were higher at LN flare and remained elevated in patients who progressed to loss of 30% of the eGFR, while they decreased in patients with stable kidney function.

CONCLUSION

The first-year course of uMCP-1 is associated with response to therapy and kidney survival in LN. Key Points •Urine MCP-1 levels differentiate histologically-active lupus nephritis from histologically-chronic lupus nephritis •Urine MCP-1 levels decrease by 3 months of therapy in subjects with a favorable response whose kidney function remains stable long-term •Urine MCP-1 levels remain elevated during the first year of therapy in subjects the will later lose kidney function.

Macrophages in Lupus Nephritis: Exploring a potential new therapeutic avenue

Lupus nephritis (LN) is a serious complication of systemic lupus erythematosus (SLE) that occurs in about half of patients. LN is characterized by glomerular deposition of immune complexes, leading to subendothelial, mesangial and subepithelial electron dense deposits, triggering immune cell infiltration and glomerular as well as tubulointerstitial injury. Monocytes and macrophages are abundantly present in inflammatory lesions, both in glomeruli and the tubulointerstitium. Here we discuss how monocytes and macrophages are involved in this process and how monocytes and macrophages may represent specific therapeutic targets to control LN.

Diagnostic test accuracy of novel biomarkers for lupus nephritis-An overview of systematic reviews

INTRODUCTION

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with multiorgan inflammatory involvement and a mortality rate that is 2.6-fold higher than individuals of the same age and sex in the general population. Approximately 50% of patients with SLE develop renal impairment (lupus nephritis). Delayed diagnosis of lupus nephritis is associated with a higher risk of progression to end-stage renal disease, the need for replacement therapy, and mortality. The initial clinical manifestations of lupus nephritis are often discrete or absent and are usually detected through complementary tests. Although widely used in clinical practice, their accuracy is limited. A great scientific effort has been exerted towards searching for new, more sensitive, and specific biomarkers in recent years. Some systematic reviews have individually evaluated new serum and urinary biomarkers tested in patients with lupus nephritis. This overview aimed to summarize systematic reviews on the accuracy of novel serum and urinary biomarkers for diagnosing lupus nephritis in patients with SLE, discussing how our results can guide the clinical management of the disease and the direction of research in this area.

METHODS

The research question is "What is the accuracy of the new serum and urinary biomarkers studied for the diagnosis of LN in patients with SLE?". We searched for systematic reviews of observational studies evaluating the diagnostic accuracy of new serum or urinary biomarkers of lupus nephritis. The following databases were included: PubMed, EMBASE, BIREME/LILACS, Scopus, Web of Science, and Cochrane, including gray literature found via Google Scholar and PROQUEST. Two authors assessed the reviews for inclusion, data extraction, and assessment of the risk of bias (ROBIS tool).

RESULTS

Ten SRs on the diagnostic accuracy of new serum and urinary BMs in LN were selected. The SRs evaluated 7 distinct BMs: (a) antibodies (anti-Sm, anti-RNP, and anti-C1q), (b) cytokines (TWEAK and MCP-1), (c) a chemokine (IP-10), and (d) an acute phase glycoprotein (NGAL), in a total of 20 review arms (9 that analyzed serum BMs, and 12 that analyzed BMs in urine). The population evaluated in the primary studies was predominantly adults. Two SRs included strictly adults, 5 reviews also included studies in the paediatric population, and 4 did not report the age groups. The results of the evaluation with the ROBIS tool showed that most of the reviews had a low overall risk of bias.

CONCLUSIONS

There are 10 SRs of evidence relating to the diagnostic accuracy of serum and urinary biomarkers for lupus nephritis. Among the BMs evaluated, anti-C1q, urinary MCP-1, TWEAK, and NGAL stood out, highlighting the need for additional research, especially on LN diagnostic panels, and attempting to address methodological issues within diagnostic accuracy research. This would allow for a better understanding of their usefulness and possibly validate their clinical use in the future.

REGISTRATION

This project is registered on the International Prospective Registry of Systematic Reviews (PROSPERO) database (CRD42020196693).

Current Insights on Biomarkers in Lupus Nephritis: A Systematic Review of the Literature

Lupus nephritis (LN) is a major cause of morbidity and mortality among patients with systemic lupus erythematosus (SLE). However, promising emerging biomarkers pave the way toward an improved management of patients with LN. We have reviewed the literature over the past decade, and we herein summarise the most relevant biomarkers for diagnosis, monitoring, and prognosis in LN. An initial systematic search of Medline was conducted to identify pertinent articles. A total of 104 studies were selected to be included in this review. Several diagnostic biomarkers, including MCP-1, TWEAK, NGAL, and uric acid, exhibited good ability to differentiate LN patients from non-renal SLE patients. Several cytokines and chemokines, including IL-10, IL-17, MCP-1, and IP-10, hold promise for assessing LN disease activity, as do cell adhesion molecules (CAMs). Angiogenesis-related and haemostasis-related proteins have also displayed potential for monitoring disease activity. Biomarkers of responses to therapy include Axl, CD163, and BAFF, whereas VCAM-1, ALCAM, and ANCAs have been reported as prognostic markers, along with traditional markers. In addition, novel renal tissue biomarkers may prove to be a useful complement to histological evaluations. The overall heterogeneity of the inclusion criteria and outcome measures across different studies, along with a lack of validation in multi-centre cohorts, call for future collaborative efforts. Nevertheless, we foresee that several biomarkers hold promise toward optimisation of the management of LN, with the use of integrated omics and panels of less invasive biomarkers paving the way towards personalised medicine.

CCR2- and CCR5-mediated macrophage infiltration contributes to glomerular endocapillary hypercellularity in antibody-induced lupus nephritis

OBJECTIVES

LN comprises various glomerular lesions, including endocapillary hypercellularity with macrophage infiltration. In this study, we aimed to clarify the involvement of macrophage-tropic chemokine receptors in the pathogenesis of these glomerular lesions.

METHODS

MRL/lpr mouse-derived monoclonal IgG3 antibody-producing hybridomas, 2B11.3 and B1, were injected intraperitoneally into BALB/c mice [wild type (WT)] to induce endocapillary hypercellularity and wire-loop lesions, respectively. The expression of chemokine and chemokine receptors was analysed by quantitative real-time PCR and IF. The roles of chemokine receptors in these lesions were evaluated using chemokine receptor-deficient mice or a selective CCR5 antagonist, maraviroc.

RESULTS

2B11.3 caused glomerular endocapillary hypercellularity with a significant number of glomerular CD68-positive macrophages. Further, enhanced expression of CCL2, CCL3, CCR2, CCR5 and CX3CR1 was observed in the renal cortex, compared with B1 injection, which induced wire-loop lesions. In 2B11.3-induced glomerular lesions, CD68 -positive glomerular macrophages expressed CCL2, CCL3, CCR2, CCR5 and CX3CR1, while glomerular endothelial cells expressed CCL2, CCL3, CX3CL1 and CCR2. When 2B11.3 was injected, CCR2-/- and CCR5-/-, but not CX3CR1-/-, mice exhibited reduced endocapillary hypercellularity, attenuated glomerular macrophage infiltration and improved serum blood urea nitrogen levels. Only CCR2-/- mice developed wire-loop lesions. B1 injection caused wire-loop lesions in these chemokine receptor-deficient mice to a similar extent as WT. Maraviroc treatment reduced 2B11.3-induced endocapillary hypercellularity and improved serum blood urea nitrogen levels.

CONCLUSION

CCR2 and CCR5 regulate glomerular macrophage infiltration and contribute to the development of glomerular endocapillary hypercellularity in LN. CCR5 inhibition can be a specific therapy for endocapillary hypercellularity without inducing wire-loop lesions.

Diagnostic, predictive and prognostic biomarkers in systemic lupus erythematosus: current insights

PURPOSE OF REVIEW

Biomarkers for diagnosis, monitoring and prognosis still constitute an unmet need for systemic lupus erythematosus (SLE). Focusing on recent findings, this review summarises the current landscape of biomarkers in lupus.

RECENT FINDINGS

Urine activated leukocyte cell adhesion molecule (ALCAM) exhibited good diagnostic ability in SLE and lupus nephritis (LN) whereas cerebrospinal fluid neutrophil gelatinase-associated lipocalin (NGAL) showed promise in neuropsychiatric SLE. Urine ALCAM, CD163 and vascular cell adhesion molecule 1 (VCAM-1) may be useful in surveillance of LN. Urine monocyte chemoattractant protein 1 was found to predict treatment response in SLE, and urine CD163 and NGAL treatment response in LN. Serum complement component 3 (C3) and urinary VCAM-1 have been reported to portend long-term renal prognosis in LN.

SUMMARY

NGAL holds promise as a versatile biomarker in SLE whereas urine ALCAM, CD163 and VCAM-1 displayed good performance as biomarkers in LN. The overall lack of concerted corroboration of leading candidates across multiple cohorts and diverse populations leaves the current biomarker landscape in SLE in an urgent need for further survey and systematic validation.

The lupus nephritis management renaissance

Over the past year, and for the first time ever, the US Food and Drug Administration approved 2 drugs specifically for the treatment of lupus nephritis (LN). As the lupus community works toward understanding how to best use these new therapies, it is also an ideal time to begin to rethink the overall management strategy of LN. In addition to new drugs, this must include how to use kidney biopsies for management and not just diagnosis, how molecular technologies can be applied to interrogate biopsies and how such data can impact management, and how to incorporate LN biomarkers into management paradigms. Herein, we will review new developments in these areas of LN and put them into perspective for disease management now and in the future.

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.