Role of early repeated renal biopsies in lupus nephritis

II Brazilian Society of Rheumatology consensus for lupus nephritis diagnosis and treatment

OBJECTIVE

To develop the second evidence-based Brazilian Society of Rheumatology consensus for diagnosis and treatment of lupus nephritis (LN).

METHODS

Two methodologists and 20 rheumatologists from Lupus Comittee of Brazilian Society of Rheumatology participate in the development of this guideline. Fourteen PICO questions were defined and a systematic review was performed. Eligible randomized controlled trials were analyzed regarding complete renal remission, partial renal remission, serum creatinine, proteinuria, serum creatinine doubling, progression to end-stage renal disease, renal relapse, and severe adverse events (infections and mortality). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to develop these recommendations. Recommendations required ≥82% of agreement among the voting members and were classified as strongly in favor, weakly in favor, conditional, weakly against or strongly against a particular intervention. Other aspects of LN management (diagnosis, general principles of treatment, treatment of comorbidities and refractory cases) were evaluated through literature review and expert opinion.

RESULTS

All SLE patients should undergo creatinine and urinalysis tests to assess renal involvement. Kidney biopsy is considered the gold standard for diagnosing LN but, if it is not available or there is a contraindication to the procedure, therapeutic decisions should be based on clinical and laboratory parameters. Fourteen recommendations were developed. Target Renal response (TRR) was defined as improvement or maintenance of renal function (±10% at baseline of treatment) combined with a decrease in 24-h proteinuria or 24-h UPCR of 25% at 3 months, a decrease of 50% at 6 months, and proteinuria < 0.8 g/24 h at 12 months. Hydroxychloroquine should be prescribed to all SLE patients, except in cases of contraindication. Glucocorticoids should be used at the lowest dose and for the minimal necessary period. In class III or IV (±V), mycophenolate (MMF), cyclophosphamide, MMF plus tacrolimus (TAC), MMF plus belimumab or TAC can be used as induction therapy. For maintenance therapy, MMF or azathioprine (AZA) are the first choice and TAC or cyclosporin or leflunomide can be used in patients who cannot use MMF or AZA. Rituximab can be prescribed in cases of refractory disease. In cases of failure in achieving TRR, it is important to assess adherence, immunosuppressant dosage, adjuvant therapy, comorbidities, and consider biopsy/rebiopsy.

CONCLUSION

This consensus provides evidence-based data to guide LN diagnosis and treatment, supporting the development of public and supplementary health policies in Brazil.

The STING inhibitor (ISD-017) reduces glomerulonephritis in 129.B6.Fcgr2b-deficient mice

The absence of stimulator of interferon genes (STING) in 129.B6.Fcgr2b-deficient mice rescue lupus phenotypes. The administration of a STING inhibitor (ISD017) into the young 129.B6.Fcgr2b-deficient mice prevents lupus nephritis development. This study mainly aimed to evaluate the effects of STING inhibition (ISD107) on established SLE in mice to prove that ISD017 could be a good therapeutic drug to reverse the already set-up autoimmunity and kidney impairment. Twenty-four-week-old Fcgr2b-deficient mice were treated with cyclophosphamide (25 mg/kg, intraperitoneal, once per week), ISD017 (10 mg/kg, intraperitoneal, three times per week), or control vehicle for 8 weeks, and were analyzed for phenotypes. Both ISD017 and cyclophosphamide treatment increased long-term survival and reduced the severity of glomerulonephritis in Fcgr2b-deficient mice. While cyclophosphamide reduced activated B cells (B220+GL-7+), ISD017 decreased activated T cells (CD4+CD69+) and neutrophils (Ly6c+Ly6g+) in Fcgr2b-deficient mice. In addition, ISD017 reduced IL-1β and interferon-inducible genes. In summary, ISD017 treatment in symptomatic 129.B6.Fcgr2b-deficient mice reduced the severity of glomerulonephritis and increased long-term survival. ISD017 worked comparably to cyclophosphamide for treating lupus nephritis in 129.B6.Fcgr2b-deficient mice. ISD017 reduced activated T cells and neutrophils, while cyclophosphamide targeted activated B cells. These results suggested that STING inhibitors can potentially be a new therapeutic drug for treating lupus.

A nomogram predicting the histologic activity of lupus nephritis from clinical parameters

BACKGROUND

The 2021 clinical guidelines of the Kidney Disease: Improving Global Outcomes emphasize the importance of the histological activity index (AI) in the management of lupus nephritis (LN). Patients with LN and a high AI have poor renal outcomes and high rates of nephritic relapse. In this study we constructed prediction models for the AI in LN.

METHODS

The study population comprised 337 patients diagnosed with LN using kidney biopsy. The participants were randomly divided into training and testing cohorts. They were further divided into high-activity (AI >2) and low-activity (AI ≤2) groups. This study developed two clinical prediction models using logistic regression and least absolute shrinkage and selection operator (LASSO) analyses with laboratory test results collected at the time of kidney biopsy. The performance of models was assessed using 5-fold cross-validation and validated in the testing cohort. A nomogram for individual assessment was constructed based on the preferable model.

RESULTS

Multivariate analysis showed that higher mean arterial pressure, lower estimated glomerular filtration rate, lower complement 3 level, higher urinary erythrocytes count and anti-double-stranded DNA seropositivity were independent risk factors for high histologic activity in LN. Both models performed well in the testing cohort regarding the discriminatory ability to identify patients with an AI >2. The average area under the curve of 5-fold cross-validation was 0.855 in the logistic model and 0.896 in the LASSO model. A webtool based on the LASSO model was created for clinicians to enter baseline clinical parameters to produce a probability score of an AI >2.

CONCLUSIONS

The established nomogram provides a quantitative auxiliary tool for distinguishing LN patients with a high AI and helps physicians make clinical decisions in their comprehensive assessment.

Kidney Biopsy in Management of Lupus Nephritis: A Case-Based Narrative Review

Kidney involvement in patients with lupus highly increases morbidity and mortality. In recent years, several reports have emphasized the dissociation between clinical and histological findings and highlighted the role of kidney biopsy as an instrument for diagnosis and follow-up of lupus nephritis. The kidney biopsy at initial diagnosis allows an early diagnosis, assessment of activity and chronicity, and detection of nonimmune complex nephritis. A kidney biopsy repeated months after treatment aids in the detection of persistent histological inflammation, which has been linked to the occurrence of future kidney relapses. A kidney biopsy at a relapse detects histological changes including chronic scarring. Finally, a kidney biopsy in patients with a clinical response undergoing maintenance immunosuppression may aid therapy tapering and/or suspension. The evidence supporting the use of a kidney biopsy in different scenarios across the course of lupus nephritis is heterogeneous, with most reports assessing the value for the diagnosis of a first or relapsing flare. In contrast, less evidence suggests additional therapeutic-modifying information derived from repeat posttreatment biopsies and biopsies to evaluate treatment tapering or suspension. In this clinical case-based review, we examine the role of kidney biopsy as a tool to improve clinical outcomes of patients with lupus nephritis.

Factors Associated with Worsening Interstitial Fibrosis/Tubular Atrophy in Lupus Nephritis Patients Undergoing Repeat Kidney Biopsy

Background

Lupus nephritis (LN) is one of the most severe manifestations of systemic lupus erythematosus (SLE). Interstitial fibrosis/tubular atrophy (IFTA) on kidney biopsies strongly predicts progression to end-stage renal disease. However, factors associated with progression of IFTA are not known. The objective of this study was to evaluate the demographic, clinical, and histopathological factors at the time of index kidney biopsies that are associated with worsening IFTA on repeat biopsies.

Methods

Patients with LN Class I to V or mixed LN on index biopsies who underwent a clinically indicated repeat biopsy between 2004 and 2020 were identified. None-mild IFTA was defined as < 25% acreage of the interstitium affected by fibrosis and atrophy, and moderate-severe IFTA was defined as ≥ 25% of the interstitium affected. Patients with none-mild IFTA on index biopsies who progressed to moderate-severe IFTA on repeat biopsies were defined as progressors. Patients with none-mild IFTA on both biopsies were defined as non-progressors.

Results

Seventy-two patients who underwent clinically indicated repeat kidney biopsies were included, and 35 (49%) were identified as progressors. Compared to non-progressors, progressors had a higher proportion of proliferative LN (20 [57%] vs. 6 [17%], p = 0.002) and crescents (9 [26%] vs. 3 [8%], p = 0.045) on index biopsies. There was no difference regarding the time to repeat biopsy or the baseline characteristics, including eGFR, presence of hypertension and diabetes, urine protein to creatinine ratio, or the initial treatments.

Conclusions

Proliferative LN and the presence of crescents on index biopsies were associated with subsequent IFTA progression on repeat biopsies. This association indicates that glomerular damage is one of the major drivers of tubulointerstitial scarring in SLE. IFTA progression may, in turn, be the driving factor of poor treatment response and progression to chronic kidney disease.

Is per-protocol kidney biopsy required in lupus nephritis?

Baseline kidney biopsy is recommended in lupus nephritis (LN). Biopsy allows to classify different forms of LN and differentiate other forms of renal involvement, such as tubulo-interstitial nephritis or thrombotic microangiopathy. The indications for repeat biopsy are more controversial. Some authors feel that good clinical monitoring is sufficient to assess prognosis and make therapeutic decisions. Based on the recently demonstrated discordance between clinical and histological response, some physicians recommend per-protocol biopsies either at 6 months in stable patients to verify the response to induction therapy, or after one-to-two years to assess treatment efficacy and tune the duration of maintenance therapy. Others recommend repeating kidney biopsy in case of incomplete response or to discriminate between active and chronic lesions. By definition, a per-protocol kidney biopsy differs from a repeat biopsy in that the former is foreseen at fixed timepoints, regardless of the clinical response. Although any decision should always consider the patient's overall clinical condition, there are no doubts that repeat kidney biopsy represents a useful tool in difficult cases to evaluate treatment response, modulate treatment intensity, and predict long-term renal outcome both in quiescent lupus and during flares. How to harmonize per-protocol biopsies in the LN course remains challenging.

When should targeted therapies be used in the treatment of lupus nephritis: Early in the disease course or in refractory patients?

Although the prognosis of lupus nephritis (LN) has improved over the last few decades, 5-20% of patients still progress to kidney failure. Hence, there is an unmet need to improve the management of LN. Two novel drugs, belimumab and voclosporin, have been recently approved for LN and obinutuzumab is in the late stage of development. In randomised controlled trials (RCTs), all these drugs, added to the standard-of-care, were more effective than standard-of-care alone in achieving renal response. Now the question is: should these new drugs be used early in the disease course or just in refractory patients? The main reasons supporting the early use are based on the RCTs that demonstrated benefits when combinatory regimen was initiated early in incident and relapsing patients leading to a higher proportion of patients to achieve renal response, hence reducing nephron loss and the risk of kidney failure. The main reasons supporting the use of the combinatory regimens primarily in relapsing/refractory patients acknowledge that many patients responded well even without add-on medications, allowing a more economic use of innovative and costly drugs. However, good predictors of renal response to standard-of-care are lacking and, thus, the decision of adding new treatments early or just in refractory or relapsing patients has to consider drug access, risks of over or undertreatment, and preservation of kidney function in high-risk individuals.

Kidney involvement in systemic lupus erythematosus: From the patient assessment to a tailored treatment

In the last few years, several studies have provided new evidence for the diagnosis, management, and follow-up of patients with lupus nephritis. Evidence showing dissociation between clinical and histological findings has prompted reevaluation of the role of the kidney biopsy as a tool for diagnosis and follow-up. In therapeutics, four immunosuppressive schemes now have supporting evidence for use as initial therapy. Current challenges include individualized selection of the best immunosuppressive regimen, an unmet need for non-invasive biomarkers of disease activity to inform treatment responses and guide subsequent therapy, holistic patient management in this complex, multisystem disease, and ultimately the development of more targeted therapies directed at specific effector pathways driving glomerular inflammation and damage in order to improve treatment response. In this communication, we review the diagnostic and therapeutic approach to lupus nephritis, as well as evaluation of response to therapy and disease control.

V-Set Immunoglobulin Domain-Containing Protein 4 as a Novel Serum Biomarker of Lupus Nephritis and Renal Pathology Activity

OBJECTIVE

To discover novel serum biomarkers that have diagnostic or predictive value in lupus nephritis (LN).

METHODS

Using a quantitative protein microarray, we screened for high-abundant proteome expression in the serum of patients with LN compared to healthy controls. Top candidates from this screening were validated using a larger cohort of patients with LN compared to a disease control cohort (subjects with other chronic kidney diseases) and a healthy control cohort. Promising markers were then selected using a machine-learning model and further validated with a larger patient cohort. The corresponding autoantibodies and immune complexes containing these proteins were also examined.

RESULTS

In total, 13 proteins were found to be significantly elevated in LN patient serum in the screening, among which 8 proteins were validated by enzyme-linked immunosorbent assay using 81 serum samples from LN patients and control subjects. Three serum markers with LN diagnostic potential were identified using feature importance analysis and further validated using 155 serum samples from LN patients and control subjects. V-set immunoglobulin domain-containing protein 4 (VSIG4) appeared to be the most promising marker in distinguishing LN from healthy controls, with an area under the curve of 0.93. VSIG4 could also discriminate active LN from inactive LN. Furthermore, serum VSIG4 levels were positively correlated with all of the following clinical parameters: the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score (Spearman's rank correlation rs = 0.42, P < 0.001), the renal domain score of the SLEDAI (rs = 0.46, P < 0.001), the urinary protein-to-creatinine ratio (rs = 0.56, P < 0.001), and the serum creatinine level (rs = 0.41, P < 0.001). Importantly, we found that serum VSIG4 levels tracked with LN disease activity longitudinally, and that serum VSIG4 levels reflected the renal pathology activity index (AI), particularly the AI components of crescent formation and hyaline deposits.

CONCLUSION

VSIG4 may be a promising novel serum biomarker and therapeutic target in patients with LN.

[Diagnostic and therapy of lupus nephritis - 2023]

The manuscript summarizes the consensus of the Austrian Society of Nephrology on the diagnosis and therapy of lupusnephritis, which is built on existing studies and literature. We discuss in detail the immunosuppressive treatment in proliferative forms of lupusnephritis (III and IV ± V) and in pure lupusnephritis V with nephrotic-range proteinuria. Furthermore, the supportive medication in lupusnephritis is summarized in the consensus. The figures were designed to provide the reader a guidance through the therapeutical approach in lupusnephritis for the daily practice.

Remission of lupus nephritis: the trajectory of histological response in successfully treated patients

OBJECTIVE

This study investigated changes in kidney histology over time in patients with lupus nephritis (LN) undergoing immunosuppressive treatment.

METHODS

Patients with proliferative±membranous LN were studied. After a diagnostic kidney biopsy (Bx1), patients had protocol biopsy 2 (Bx2) at 9 (6-15) months and protocol biopsy 3 (Bx3) at 42 (28-67) months. Kidney histological activity and chronicity indices (AI, CI) were measured.

RESULTS

AI declined in a biphasic fashion, falling rapidly between Bx1 and Bx2 and then more slowly between Bx2 and Bx3. Patients were divided into those who achieved histological remission, defined as an AI=0 at Bx3 (group 1), and those with persistent histological activity (AI >0) at Bx3 (group 2). The early decline in AI was 1.6 times greater (95% CI 1.30, 1.91) in group 1 than group 2 (p=0.01). Between Bx2 and Bx3, the AI decline was 2.19-fold greater (95% CI 2.09, 2.29) in group 1 versus group 2 (p=7.34×10-5). Individual histological components of the AI resolved at different rates. Inflammatory lesions like glomerular crescents, karyorrhexis and necrosis mostly resolved by Bx2, whereas endocapillary hypercellularity, subendothelial hyaline deposits and interstitial inflammation resolved slowly, accounting for residual histological activity at biopsy 3 in group 2. In contrast, CI increased rapidly, by 0.15 units/month between Bx1 and Bx2, then plateaued. There were no differences in the rate of accumulation of chronic damage between group 1 and group 2. The increase in CI was significantly related to the severity of glomerular crescents (p=0.044), subendothelial hyaline deposits (p=0.002) and interstitial inflammation (p=0.015) at Bx1.

CONCLUSIONS

LN histological activity takes months to years to resolve, providing a rationale for the need of long-term, well-tolerated maintenance immunosuppression. Despite responding, LN kidneys accrue chronic damage early during treatment. This finding provides an explanation for the association of chronic progressive kidney disease with recurrent episodes of LN.

Treatment of lupus nephritis: consensus, evidence and perspectives

Despite the continuing development of immunomodulatory agents and supportive care, the prognosis associated with lupus nephritis (LN) has not improved substantially in the past decade, with end-stage kidney disease still developing in 5-30% of patients within 10 years of LN diagnosis. Moreover, inter-ethnic variation in the tolerance of, clinical response to and level of evidence regarding various therapeutic regimens for LN has led to variation in treatment prioritization in different international recommendations. Modalities that better preserve kidney function and reduce the toxicities of concomitant glucocorticoids are unmet needs in the development of therapeutics for LN. In addition to the conventional recommended therapies for LN, there are newly approved treatments as well as investigational drugs in the pipeline, including the newer generation calcineurin inhibitors and biologic agents. In view of the heterogeneity of LN in terms of clinical presentation and prognosis, the choice of therapies depends on a number of clinical considerations. Molecular profiling, gene-signature fingerprints and urine proteomic panels might enhance the accuracy of patient stratification for treatment personalization in the future.

Urine Galectin-3 binding protein reflects nephritis activity in systemic lupus erythematosus

BACKGROUND

Lupus nephritis (LN) is a major and severe organ involvement in systemic lupus erythematosus (SLE), whose diagnosis and treatment necessitate to perform kidney biopsy, which is an invasive procedure. Non-invasive urine biomarkers are an active area of investigation to support LN diagnosis and management.

OBJECTIVE

To investigate the role of urinary galectin-3 binding protein (u-Gal-3BP) as a candidate biomarker of renal disease in biopsy proven LN.

PATIENTS AND METHODS

Levels of u-Gal-3BP were investigated in a cross-sectional fashion by ELISA in 270 subjects: 86 LN patients, 63 active SLE patients with no kidney involvement, 73 SLE patients with inactive disease and 48 age and sex-matched population-based controls (PBC). Moreover, urine samples were analysed separately by ELISA for additional markers of kidney pathology: neutrophil gelatinase-associated lipocalin (NGAL), osteopontin (OPN), kidney injury molecule-1 (KIM-1) and galectin-3 (Gal-3). The concentrations of all studied molecules were normalized to urine creatinine levels. In 10 patients, post-treatment levels of the biomarkers were measured.

RESULTS

Normalized u-Gal-3BP levels were higher in LN patients compared to the other groups (p < .0001). Comparing different LN classes, u-Gal-3BP levels were higher among patients with proliferative (class III/IV) and membranous (class V) as compared to mesangial (class II) forms (p = .04). In proliferative forms, u-Gal-3BP levels correlated with the activity index in renal biopsies (r = 0.42, p = .004). Moreover, in a subset of 10 patients with repeated kidney biopsy and urine sampling before and after induction treatment, a significant decrease of u-Gal-3BP was observed (p = .03). Among the other markers, KIM-1 was also able to discriminate LN from the other groups, while NGAL, OPN and Gal-3 could not in this cohort.

CONCLUSION

Given its ability to discriminate LN patients from active non-renal and inactive SLE patients, the observed correlation with the activity index in renal biopsies, and its levels declining following treatment, u-Gal-3BP shows promise as a non-invasive urinary biomarker to help detecting and to monitor renal involvement in SLE patients and should be validated in larger cohorts.

High incidence of proliferative and membranous nephritis in SLE patients with low proteinuria in the Accelerating Medicines Partnership

OBJECTIVE

Delayed detection of LN associates with worse outcomes. There are conflicting recommendations regarding a threshold level of proteinuria at which biopsy will likely yield actionable management. This study addressed the association of urine protein:creatinine ratios (UPCR) with clinical characteristics and investigated the incidence of proliferative and membranous histology in patients with a UPCR between 0.5 and 1.

METHODS

A total of 275 SLE patients (113 first biopsy, 162 repeat) were enrolled in the multicentre multi-ethnic/racial Accelerating Medicines Partnership across 15 US sites at the time of a clinically indicated renal biopsy. Patients were followed for 1 year.

RESULTS

At biopsy, 54 patients had UPCR <1 and 221 had UPCR ≥1. Independent of UPCR or biopsy number, a majority (92%) of patients had class III, IV, V or mixed histology. Moreover, patients with UPCR <1 and class III, IV, V, or mixed had a median activity index of 4.5 and chronicity index of 3, yet 39% of these patients had an inactive sediment. Neither anti-dsDNA nor low complement distinguished class I or II from III, IV, V or mixed in patients with UPCR <1. Of 29 patients with baseline UPCR <1 and class III, IV, V or mixed, 23 (79%) had a UPCR <0.5 at 1 year.

CONCLUSION

In this prospective study, three-quarters of patients with UPCR <1 had histology showing class III, IV, V or mixed with accompanying activity and chronicity despite an inactive sediment or normal serologies. These data support renal biopsy at thresholds lower than a UPCR of 1.

Identification and analysis of the predictive urinary exosomal miR-195-5p in lupus nephritis based on renal miRNA-mRNA co-expression network

OBJECTIVE

Lupus nephritis (LN) is the main complication of systemic lupus erythematosus (SLE), causing huge financial burden and poor quality of life. Due to the low compliance of renal biopsy, we aim to find a non-invasive biomarker of LN to optimize its predictive, preventive, and personalized medical service or management.

METHOD

Herein, we provided a bioinformatic screen combined clinical validation strategy for rapidly mining exosomal miRNAs for LN diagnosis and management. We screened out differentially expressed miRNAs (DEMs) and differentially expressed mRNAs (DEGs) in LN database and performed a miRNA-mRNA integrated analysis to select out reliable changed miRNAs in LN tissues by using R and Cytoscape. Urinary exosomes were collected by ultracentrifugation and analyzed by nano-tracking analysis and western blotting. Detection of aquaporin-2 showed the tubular source of urinary exosomes. Urinary exosomal miRNAs were detected by RT-qPCR and the target of miR-195-5p was verified by using bioinformatic, dual-luciferase, and western blotting.

RESULT

15 miRNAs and their 60 target mRNAs were contained in miRNA-mRNA integrated map. Bioinformatic analysis showed these miRNAs were involved in various cellular biological process. Exosomal miR-195-5p, miR-25-3p, miR-429, and miR-218-5p were verified in a small clinical group (n = 47). Urinary exosomal miR-195-5p, miR-25-3p, and miR-429 were downregulated in patients and miR-195-5p could recognize LN patients from SLE with good sensitivity and specificity, showing good potential in LN disease monitoring and diagnosis.

CONCLUSION

We analyzed and obtained a series of differential miRNAs in LN kidney tissues and suggested that urinary exosomal miR-195-5p could serve as a novel biomarker in LN. Further, miR-195-5p-CXCL10 axis could be a therapeutic target of LN.

Lupus nephritis: new progress in diagnosis and treatment

Systemic lupus erythematosus (SLE) is a chronic multifactorial autoimmune disease that affects many organs, including the kidney. Lupus nephritis (LN) is a common manifestation characterized by heterogeneous clinical and histopathological findings, and often associates with poor prognosis. The diagnosis and treatment of LN is challenging, depending largely on renal biopsy, and there is no reliable non-invasive LN biomarker. Up to now, the complete remission rate of LN is only 20%∼30% after receiving six months of standard treatment, which is far from satisfactory. Moreover, adverse reactions to immunosuppressants, especially glucocorticoids, further compromise the prognosis of LN. Biological reagents targetting autoimmune responses and inflammatory pathways, bring hope to the treatment of intractable lupus. The European Renal Association-European Dialysis and Transplant Association (EULAR/ERA-EDTA) and KDIGO (Kidney Disease: Improving Global Outcomes) have been working on and launched the recommendations for the management of LN. In this review, we update our knowledge in the pathogenesis, diagnosis, and management of LN and prospect for the future potential targets in the management of LN.

Predictors of increase in chronicity index and of kidney function impairment at repeat biopsy in lupus nephritis

OBJECTIVES

Based on available data, the histological predictors of long-term outcome of lupus nephritis (LN) are not clearly defined. Aims of this retrospective study were: (i) to evaluate the change of chronicity index from the first to second kidney biopsy and to find the predictors of chronicity index increase and (ii) to detect the clinical/histological features at first and at second kidney biopsy associated with long-term kidney function impairment.

METHODS

Among 203 biopsy proven LN subjects, 61 repeated kidney biopsy 49 months after the first biopsy. The reasons for repeated biopsy were: nephritic flares in 25 (41%), proteinuric flares in 21 (36%) of patients and protocol biopsy in 14 (23%) of cases.

RESULTS

During 23-year follow-up, 25 patients presented a decrease in glomerular filtration rate (eGFR) ≥30%. At repeat biopsy, chronicity index increased in 44 participants (72%) and did not increase in 17 (28%). Nephritic syndrome and serum creatinine >1.6 mg/dL at presentation correlated with chronicity index increase (p=0.031, 0.027, respectively), cyclophosphamide therapy tended to protect against chronicity index increase (p=0.059). Kidney flares occurred in 53.6% of patients with vs 23.5% of those without chronicity index increase (p=0.035). Chronicity index increases of 3.5 points in patients with kidney flares vs 2 in those without flares (p=0.001). At second, but not at first kidney biopsy, two different models predicted eGFR decrease at multivariate analysis. The first included activity index >3 (OR: 3.230; p=0.013) and chronicity index >4 (OR: 2.905; p=0.010), and the second model included moderate/severe cellular/fibrocellular crescents (OR: 4.207; p=0.010) and interstitial fibrosis (OR: 2.525; p=0.025).

CONCLUSION

At second biopsy, chronicity index increased in 3/4 of participants. Its increase was predicted by kidney dysfunction at presentation and occurrence of LN flares. Kidney function impairment was predicted by both activity and chronicity index and by some of their components at repeated biopsy, but not at first biopsy.

Urinary HER2, TWEAK and VCAM-1 levels are associated with new-onset proteinuria in paediatric lupus nephritis

Objective

Lupus nephritis is a key driver of morbidity and mortality in SLE. Detecting active nephritis on a background of pre-existing renal damage is difficult, leading to potential undertreatment and accumulating injury. An unmet need is a biomarker that distinguishes active lupus nephritis, particularly important in paediatrics where minimising invasive procedures is desirable.

Methods

This was a multicentre, prospective study of 113 paediatric patients with biopsy-proven lupus nephritis. Clinical data and urine were obtained every 3–4 months and patients averaged 2 years on study with seven time points. Urine was analysed for human epidermal growth factor receptor 2 (HER2), tumour necrosis factor-like weak inducer of apoptosis and vascular cell adhesion molecule-1 (VCAM-1) by ELISA. We defined active disease as either a rise in serum creatinine ≥0.3 mg/dL from baseline or a rise in renal Systemic Lupus Erythematosus Disease Activity Index score from the previous visit. These markers were also studied in patients with acute kidney injury, juvenile idiopathic arthritis (JIA), amplified pain syndrome and healthy controls.

Results

The rate of active disease was 56% over an average of 2 years of follow-up. HER2 and VCAM-1 were significantly elevated at time points with active disease defined by increased serum creatinine compared with time points with inactive disease or patients who never flared. All three biomarkers were associated with new-onset proteinuria and VCAM-1 was elevated at time points preceding new-onset proteinuria. These biomarkers were not increased in acute kidney injury or JIA.

Conclusion

All three biomarkers were associated with new onset proteinuria and increased VCAM-1 may predict impending proteinuria. These biomarkers provide potential non-invasive measures for monitoring that may be more sensitive to impending flare than conventional measures.

Triglycerides as Biomarker for Predicting Systemic Lupus Erythematosus Related Kidney Injury of Negative Proteinuria

Fewer biomarkers can be used to predict systemic lupus erythematosus (SLE) related kidney injury. This paper presents an apriori algorithm of association rules to mine the predictive biomarkers for SLE-related kidney injury of negative proteinuria. An apriori algorithm of association rules was employed to identify biomarkers, and logistic regression analysis and spearman correlation analysis were used to evaluate the correlation between triglycerides and SLE-related kidney injury of negative proteinuria. Triglycerides were mined out by the apriori algorithm of association rules. The level of triglycerides was significantly higher, and it was an independent risk factor for SLE-related kidney injury. In the high-triglycerides group, the number of patients with SLE-related kidney injury, SLEDAI-2K, urine P-CAST, the level of blood urea nitrogen, serum creatinine, and proteinuria were increased. Triglycerides level was positively correlated with proteinuria and P-CAST and negatively correlated with albumin and IgG. The area under the ROC curve of triglycerides and triglycerides combined proteinuria was 0.72 and 0.82, respectively. Significantly, 50% of SLE-related kidney injuries of negative proteinuria could be identified by high triglycerides levels. High triglycerides level was found at the time of onset of kidney injury, and it was opposite to glomerular filtration rate. Triglycerides may be a potential marker for predicting SLE-related kidney injury, especially in SLE-related kidney injury of negative proteinuria. Triglycerides combined proteinuria could predict SLE-related kidney injury effectively.

Kidney biopsy in lupus nephritis after achieving clinical renal remission: paving the way for renal outcome assessment

The role of repeat kidney biopsy in lupus nephritis (LN) with renal remission is unclear. The aim of this study was to assess this role in a real-life scenario. This retrospective, single-centre study included 56 patients with LN diagnosed from 1998 to 2019, with an initial kidney biopsy (KB1) at the onset of LN and a second kidney biopsy (KB2) after achieving renal remission. A total of 51 (91.1%) patients were women with a median age of 29.9 years [interquartile range (IQR) 23.4–40.6] at the time of LN diagnosis. KB2s were performed after 41.1 months (IQR 30.1–52.5) of KB1. At the time of KB2, complete renal response was achieved in 51 (91.1%) patients. The median activity index decreased from a baseline value of 6.5 (IQR 2.8–11) to 0 (IQR 0–2) (P < .001). The chronicity index worsened from 1 (IQR 0–2) to 2 (IQR 1–3) (P = .01). In patients with proliferative/mixed forms at KB2, the chronicity index median value increased to 3 (IQR 1.5–4), as well as interstitial fibrosis and tubular atrophy \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$\ge $\end{document}25%, from 5.4% to 13.5%. Persistent histological active LN (activity index ≥2) was present in 11 (19.6%) KB2s. There were no differences when comparing immunological parameters between both groups (activity index ≥2 versus <2) at KB2, nor in the percentage of patients who presented renal flare. Immunosuppressive treatment was withdrawn in 35 (62.5%) patients and maintained/switched in 21 (37.5%). Afterward, new renal flare occurred in 9 patients per group (25.7% and 43%, respectively), after a median time of 39 months (IQR 6.5–55) and 7 months (IQR 6–30), respectively. There was no difference in the number of patients who developed chronic kidney disease [n = 14 (25%)] according to the treatment. In conclusion, KB2 provides valuable information to guide immunosuppressive maintenance therapy.

Management practice and treatment outcomes of adult patients with Lupus Nephritis at the Renal Clinic of St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia

Background

Lupus nephritis (LN) is the most common severe complication of systemic lupus erythematosus (SLE) which results in high morbidity and mortality. Up to 60% of adult patients with SLE develop the renal disease with different severity. Even with potent anti-inflammatory and immunosuppressive therapies, many LN patients still progress to chronic kidney disease or end-stage renal disease. Thus, this study aimed to assess the management practice, treatment outcomes and to identify the associated factors of poor renal outcome in adult LN patients at the renal clinic of St. Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia.

Methods

A retrospective cross-sectional study design was used to collect the data using an abstraction tool from patients’ records. The Kidney Disease Improving Global Outcomes (KDIGO) criteria were used to diagnose LN among SLE patients. Logistic regression was used to determine crude and adjusted odds ratio and a p-value of < 0.05 was considered statistically significant. Ethical approval was obtained from the ethical review committee of the School of Pharmacy, Addis Ababa University and institutional review board of St. Paul’s Hospital Millennium Medical College.

Results

Out of 168 study participants enrolled from September 1, 2016 to October 30, 2020, a total of 114 adult LN patients were included for final analysis. The mean (± SD) age of the LN patients at onset was 29.10 ± 9.67 years and 99 (86.8%) of all the patients were females. More than three-fourths (78.9%) of the LN patients had a good prognosis. However, 24 (21.1%) of the patients who didn’t achieve complete or partial remission had a poor prognosis. A kidney biopsy was done for 71 patients at initial presentation with class IV and III as the commonest class. The commonly prescribed immunosuppressive medications were cyclophosphamide as induction therapy in 67 (58.7%) and mycophenolate mofetil (MMF) as maintenance therapy in 76 (66.7%). Gastrointestinal intolerances like abdominal pain, nausea, or diarrhea from MMF were the most common 27(31.2%) treatment-related adverse events reported. Acute kidney injury (AKI) at onset (AOR = 4.83, P = 0.026), high serum creatinine (SCr) at six months (AOR = 0.12, P = 0.003), no response at six months to attain complete remission (AOR = 0.05, P = 0.041) and presence of flare (AOR = 0.04, P = 0.004) were predictors poor treatment outcomes.

Conclusion

Despite good response with the present immunosuppressive regimens, relapse, treatment-related complications and adverse events are major problems that require close monitoring. The results and identified gaps of this study are used as an input to improve the management practice of LN in the study setting. Overall, this study is comparable with other findings and strengthen the present available literatures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02846-z.

A Histology-Guided Approach to the Management of Patients with Lupus Nephritis: Are We There Yet?

Renal involvement is a frequent complication of systemic lupus erythematosus (SLE). It occurs in up to two-thirds of patients, often early during the disease course, and is the most important predictor of the morbidity and mortality of SLE patients. Despite tremendous improvements in the approach of the lupus nephritis (LN) therapy, including the recent approval of two new disease-modifying therapies, up to 50% of patients do not obtain a renal response and up to 25% will eventually progress to end-stage renal disease (ESRD) within 10 years of diagnosis. Given the lack of correlation between clinical features and histological lesions, there is an increasing need for a histology-guided approach to the management of patients with LN. Apart from the initial diagnosis of type and severity of renal injury in SLE, the concept of a repeat kidney biopsy (either in a for-cause or a per-protocol scenario) has begun to gain increasing popularity in the nephrology community. Herein, we will provide a comprehensive overview of the most important areas of utility of the kidney biopsy in patients with LN.

Clinical and histological findings at second but not at first kidney biopsy predict end-stage kidney disease in a large multicentric cohort of patients with active lupus nephritis

Objective

To investigate second kidney biopsy as predictor of end-stage kidney disease (ESKD) in active lupus nephritis (LN).

Methods

Patients with biopsy-proven LN (International Society of Nephrology/Renal Pathology Society 2003) who had undergone a second kidney biopsy between January 1990 and December 2018 were included. Clinical and histological findings at first and at second biopsy were analysed with Cox proportional hazard models to predict ESKD, defined as start of kidney replacement therapy. Survival curves were calculated with Kaplan-Meier method.

Results

Ninety-two patients with LN were included, 87% females, mean follow-up 17.9±10.1 years. Reasons for second kidney biopsy encompassed nephritic flares (n=28, 30.4%), proteinuric flares (n=46, 50%) or lack of renal response (n=18, 19.5%). Class switch from first biopsy occurred in 50.5% of cases, mainly from non-proliferative towards proliferative classes. Class IV remained stable in over 50% of cases. Twenty-five patients (27.2%) developed ESKD, mostly belonging to the nephritic flare group (17/28, 60.7%). Independent predictors of ESKD at second biopsy were activity index (AI; (HR 95% CI) 1.20 (1.03 to 1.41), p=0.022), chronicity index (CI; 1.41 (1.09 to 1.82), p=0.008) and 24h-proteinuria (1.22 (1.04 to 1.42), p=0.013). AI≥2 (log-rank p=0.031), CI >4 (log-rank p=0.001) or proteinuria ≥3.5 g/day (log-rank=0.009) identified thresholds for higher ESKD risk. In a subgroup analysis, glomerular activity and tubular chronicity mostly accounted for AI and CI association with ESKD. No histological or laboratory predictors emerged at first biopsy (95% CI): AI: 0.88 to 1.19; CI: 0.66 to 1.20; proteinuria 0.85 to 1.08.

Conclusions

Findings at second but not at first kidney biopsy in patients with persistently active or relapsing LN inform about ESKD development in a long-term follow-up.

New Treatment Options in Lupus Nephritis

The aim of this study is to report major recent progresses in the treatment of lupus nephritis (LN). Results of controlled randomized trials are discussed in view of the unmet needs in the field. Current treatments of LN are not satisfactory, with a disappointing proportion of 20-30% of patients achieving complete renal response within 6-12 months, and 5-20% developing end-stage kidney disease within ten years. Two drugs (belimumab and voclosporin) have been officially registered by the medical agencies as add on treatment of LN, a first-in-history success after decades of use of non-registered drugs and trial failures. Other targeted therapies (obinutuzumab and anifrolumab) are currently tested in Phase III trials, after interesting results in Phase II studies. Unanswered questions related to the use of these new drugs are discussed. Recent trials have opened new avenues for the treatment of LN which will hopefully reduce the rate of chronic kidney disease.

Treat-to-Target in Lupus Nephritis. What is the Role of the Repeat Kidney Biopsy?

Kidney involvement, termed lupus nephritis (LN), develops in 35-60% of patients with systemic lupus erythematosus, often early during the disease course. When not treated promptly and efficiently, LN may lead to rapid and severe loss of kidney function, being the reason why it is considered one of the most severe lupus manifestations. Despite improved pharmacotherapy, 5-20% of LN patients develop end-stage kidney disease within ten years from the LN diagnosis. While the principal ground of LN therapy is prevention of renal function worsening, resembling a race against nephron loss, consensual agreement upon outcome measures and clinically meaningful short- and long-term targets of LN therapy have yet to be determined. Literature points to the importance of inclusion of tissue-based approaches in the determination of those targets, and evidence accumulates regarding the importance of per-protocol repeat kidney biopsies in the evaluation of the initial phase of therapy and prediction of long-term renal prognosis. The latter leads to the hypothesis that the information gleaned from repeat biopsies may contribute to optimised therapeutic decision making, and, therefore, increased probability to attain complete renal response in the short term, and a more favourable renal prognosis within a longer prospect. The multinational project ReBioLup was recently designed to serve as a key contributor to form evidence about the role of per-protocol repeat biopsies in a randomised fashion and aspires to unify the global LN community towards improved kidney and patient survival.

Change of Renal Gallium Uptake Correlated with Change of Inflammation Activity in Renal Pathology in Lupus Nephritis Patients

Background: Lupus nephritis (LN) often lead to end-stage renal disease in systemic lupus erythematosus patients. This study aimed to investigate the clinical application of renal gallium-67 scans for determining renal histological parameters in LN patients. Methods: Between 2006 and 2018, 237 biopsy-proven and 35 repeat biopsies LN patients who underwent renal gallium scans before or after biopsy were included for analysis. The classification and scoring of LN were assessed according to the International Society of Nephrology/Renal Pathology Society. A delayed 48-h gallium scan was performed and interpreted by semiquantitative methods using left kidney/spine (K/S) ratio. The renal histological results were compared with gallium uptake. Results: Out of 237 participants, 180 (76%) had proliferative LN. Baseline gallium left K/S ratio was significantly higher in class IV LN as compared to class III (median (interquartile range, IQR): 1.16 (1.0–1.3), 0.95 (0.9–1.1), respectively, p < 0.001). Furthermore, changes in gallium uptake between two biopsies were positively correlated with changes activity index (r = 0.357, p = 0.035), endocapillary hypercellularity (r = 0.385, p = 0.032), and neutrophils infiltration (r = 0.390, p = 0.030) in renal pathology. Conclusions: Renal gallium uptake is associated with active inflammation in LN. Changes in renal gallium uptake positively correlated with changes in activity index in renal pathology.

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.

From sequential to combination and personalised therapy in lupus nephritis: moving towards a paradigm shift?

The current treatment paradigm in lupus nephritis consists of an initial phase aimed at inducing remission and a subsequent remission maintenance phase. With this so-called sequential treatment approach, complete renal response is achieved in a disappointing proportion of 20-30% of the patients within 6-12 months, and 5-20% develop end-stage kidney disease within 10 years. Treat-to-target approaches are detained owing to uncertainty as to whether the target should be determined based on clinical, histopathological, or immunopathological features. Until reliable non-invasive biomarkers exist, tissue-based evaluation remains the gold standard, necessitating repeat kidney biopsies for treatment evaluation and therapeutic decision-making. In this viewpoint, we discuss the pros and cons of voclosporin and belimumab as add-on agents to standard therapy, the first drugs to be licenced for lupus nephritis after recent successful randomised phase III clinical trials. We also discuss the prospect of obinutuzumab and anifrolumab, also on top of standard immunosuppression, currently tested in phase III trials after initial auspicious signals. Undoubtably, the treatment landscape in lupus nephritis is changing, with combination treatment regimens challenging the sequential concept. Meanwhile, the enrichment of the treatment armamentarium shifts the need from lack of therapies to the challenge of how to select the right treatment for the right patient. This has to be addressed in biomarker surveys along with tissue-level mapping of inflammatory phenotypes, which will ultimately lead to person-centred therapeutic approaches. After many years of trial failures, we may now anticipate a heartening future for patients with lupus nephritis.

Resorption of immune deposits in membranous lupus nephritis following rituximab vs conventional immunosuppressive treatment

OBJECTIVES

Studies on repeat renal biopsies in membranous LN (MLN) are limited, and evaluation of treatment response is mainly based on proteinuria. EM of renal biopsies from rituximab (RTX)-treated MLN patients has revealed resorption of sub-epithelial ICs. Whether resorption phenomena are useful for treatment evaluation, or differs between treatment regimens is not known. We studied EM findings and clinical treatment response in MLN patients after RTX vs conventional immunosuppressive treatment.

METHODS

Twenty-four patients with MLN and renal biopsies performed before and after treatment were included in this retrospective observational study. Laboratory data were collected at both biopsy occasions. Seven patients had received RTX and 17 had received conventional treatment (CYC, MMF or AZA). Electron micrographs of renal tissue were scored using an arbitrary scale (0-3) for the level of sub-epithelial ICs, resorption of ICs and podocyte fusion.

RESULTS

Sub-epithelial ICs decreased after treatment, however not significantly and with no difference between treatments. The resorption phenomena increased after RTX (P = 0.028), but not after conventional therapy (P = 0.29). Six out of seven (86%) RTX-treated patients had increased resorption vs 7/17 (41%) after conventional therapies (P = 0.047). Clinical responders had more pronounced resorption of ICs vs non-responders (P = 0.022).

CONCLUSIONS

We report increased resorption of ICs in repeat renal biopsies in MLN, especially after RTX treatment. Increased resorption phenomena were associated with clinical response, suggesting that EM findings may be useful for treatment evaluation in MLN. Although of limited size, the study indicates that RTX is effective both clinically and at a tissue level.

Management of Lupus Nephritis

Lupus nephritis (LN) is a frequent and severe manifestation of systemic lupus erythematosus. The main goal of the management of LN is to avoid chronic kidney disease (CKD). Current treatment strategies remain unsatisfactory in terms of complete renal response, prevention of relapses, CKD, and progression to end-stage kidney disease. To improve the prognosis of LN, recent data suggest that we should (i) modify our treat-to-target approach by including, in addition to a clinical target, a pathological target and (ii) switch from conventional sequential therapy to combination therapy. Here, we also review the results of recent controlled randomized trials.

Per-protocol repeat kidney biopsy portends relapse and long-term outcome in incident cases of proliferative lupus nephritis

OBJECTIVES

In patients with LN, clinical and histological responses to treatment have been shown to be discordant. We investigated whether per-protocol repeat kidney biopsies are predictive of LN relapses and long-term renal function impairment.

METHODS

Forty-two patients with incident biopsy-proven active proliferative (class III/IV±V) LN from the database of the UCLouvain were included in this retrospective study. Per-protocol repeat biopsies were performed after a median [interquartile range (IQR)] time of 24.3 (21.3-26.2) months. The National Institutes of Health activity index (AI) and chronicity index (CI) scores were assessed in all biopsies.

RESULTS

Despite a moderate correlation between urinary protein/creatinine ratios (UPCR) and AI scores at repeat biopsy (r = 0.48; P = 0.001), 10 patients (23.8%) with UPCR < 1.0 g/g still had a high degree of histological activity (AI > 3). High AI scores (continuous) in repeat biopsies were associated with an increased probability and/or shorter time to renal relapse (n = 11) following the repeat biopsy [hazard ratio (HR) = 1.2, 95% CI: 1.1, 1.3; P = 0.007], independently of proteinuria levels. High CI scores (continuous) in repeat biopsies were associated with a sustained increase in serum creatinine levels corresponding to ≥120% of the baseline value (HR = 1.8, 95% CI: 1.1, 2.9; P = 0.016) through a median (IQR) follow-up time of 131.5 (73.8-178.2) months, being also the case for acute tubulointerstitial inflammation and interstitial fibrosis/tubular atrophy in repeat but not baseline biopsies.

CONCLUSION

Our results highlight the usefulness of per-protocol repeat biopsies, herein performed after a median time of 24 months from baseline, as an integral part of the treatment evaluation, also in patients showing adequate clinical response.

Lupus nephritis: clinical presentations and outcomes in the 21st century

Lupus nephritis (LN) is a frequent and severe manifestation of SLE. Along the decades, the epidemiology of LN and its clinical presentation have been changing. However, even though retrospective cohort studies report a decreased mortality rate and an improvement in the disease prognosis, the percentage of patients progressing into end stage renal disease (ESRD) keeps steady despite the improvements in therapeutic strategies. Current in-use medications have been available for decades now, yet over the years, regimens for optimizing their efficacy and minimizing toxicity have been developed. Therapeutic research is now moving towards the direction of precision medicine and several new drugs, targeting selectively different pathogenetic pathways, are currently under evaluation with promising results. In this review, we address the main changes and persistent unmet needs in LN management throughout the past decades, with a focus on prognosis and upcoming treatments.

Value of Urinary Neutrophil Gelatinase-Associated Lipocalin versus Conventional Biomarkers in Predicting Response to Treatment of Active Lupus Nephritis

Introduction

Lupus nephritis (LN) affects almost two-thirds of systemic lupus erythematosus (SLE) patients. Despite initial aggressive therapy, up to 25% of patients with LN will progress to permanent renal damage. Conventional serum markers for LN lack the sensitivity of an ideal biomarker. Urinary neutrophil gelatinase-associated lipocalin (UNGAL) is an excellent biomarker for early diagnosis of acute kidney injury and predicting renal outcomes.

Objective

To measure UNGAL among LN patients to correlate its levels with renal disease activity and to investigate its predictive performance in response to induction therapy. Patients and Methods. 40 SLE patients with biopsy-proven LN class III, IV, or V were randomly selected. The study was conducted in the internal medicine department and outpatient clinic in Ain Shams University Hospitals and completed after six months. UNGAL was measured at baseline, three-month follow-up, and after complete induction therapy.

Results

In LN patients at baseline, the mean serum creatinine was 2.57 ± 0.96 mg/dL and the mean UNGAL was 33.50 ± 18.34 ng/dL. Mean UNGAL levels of complete response, partial response, and nonresponse groups were 14.48 ± 2.99 ng/mL, 34.49 ± 4.09 ng/mL, and 62.07 ± 14.44 ng/mL, respectively. Based on the ROC curve, we found a better performance of baseline UNGAL to discriminate the complete response group from partial and nonresponse groups to predict response to induction, outperforming conventional biomarkers. The area under the curve was 0.943, and the best cutoff level was 26.5 ng/mL (92.31% sensitivity and 88.89% specificity).

Conclusion

UNGAL performed better than conventional biomarkers in predicting response to treatment of active LN.

What is the value of repeat kidney biopsies in patients with lupus nephritis?

INTRODUCTION

Recent studies with protocol biopsies have shown a mismatch between clinical and histological remission in lupus nephritis (LN). We aimed to evaluate histological changes in repeat kidney biopsies by clinical indication in patients with LN.

METHODS

We analyzed 107 patients with LN in which a kidney biopsy was performed between 2008 and 2018. Of those, we included 26 (24.2%) who had ≥2 kidney biopsies. Classification was done according to the International Society of Nephrology/Renal Pathology Society.

RESULTS

Mean time between biopsies was 71.5 ± 10.7 months. 73.1% of patients presented a change of class at repeat biopsy; 38.4% to a higher class and 34.6% to a lower class. A significant increase in glomerulosclerosis (% GS) (3.8% vs 18.7%, p = 0.006), interstitial fibrosis (3.8% vs 26.9%, p = 0.021), tubular atrophy (15.4% vs 57.7%, p = 0.001) and chronicity index (CI) (1 vs 3, p < 0.001) was observed at repeat biopsy. Subjects who developed chronic kidney disease progression had a lower rate of complete remission at 12 months (0% vs 37.5%, p = 0.02), higher % GS at first biopsy (7.9% vs 1.2%, p = 0.02) and higher CI (4 vs 2, p = 0.006), tubular atrophy (90% vs 37.6%, p = 0.008), interstitial fibrosis (50% vs 12.5%, p = 0.036) and vascular lesions (60% vs 18.8%, p = 0.031) at second biopsy.

CONCLUSIONS

Our major finding was that patients with LN showed a significant increase in % GS, interstitial fibrosis, tubular atrophy and vascular lesions in repeat biopsies performed by clinical indication. This suggest that a second kidney biopsy may provide valuable and useful information regarding kidney disease progression.

Plasma C4d Correlates With C4d Deposition in Kidneys and With Treatment Response in Lupus Nephritis Patients

Objective

To examine whether C4d plasma levels correlate with treatment response and C4d kidney deposition in systemic lupus erythematosus (SLE) with lupus nephritis (LN).

Methods

C4d plasma levels were analyzed by a unique assay specifically detecting C4d arising from complement activation and C4 plasma levels were quantified with competitive ELISA. SLE patients with LN (71) and active SLE patients without LN (22) plus 145 controls were included. For 52 LN patients samples were available both at baseline and after immunosuppressive treatment. C4d kidney deposition was detected using immunohistochemistry in two matching kidney biopsies of 12 LN patients.

Results

In comparison to population-based controls, plasma C4d levels were significantly increased in SLE patients (0.33 mg/L versus 0.94 mg/ml, p < 0.0001) with significantly higher levels in LN patients (1.02 mg/L) than in non-renal SLE patients (0.57 mg/L, p = 0.004). The C4d/C4 ratio was also significantly higher in LN (11.2) than in non-renal SLE patients (2.5, p = 0.0002). According to ROC curve analysis, C4d was found to be an accurate marker to discriminate LN from non-renal SLE patients (p = 0.004). The C4d/C4 ratio displayed even higher specificity, sensitivity and overall accuracy as marker for LN than C4d and C4 alone. At baseline, C4d levels correlated significantly with urine-albumin to creatinine ratio (r _s = 0.43, p = 0.011) and with renal activity index (r _s = 0.37, p = 0.002). Immunohistochemical staining showed glomerular deposits of C4d in kidney biopsies, which strikingly correlated with plasma C4d levels (r _s = 0.7, p = 0.0002). Plasma C4d declined significantly after treatment in patients that experienced favorable clinical and histopathological response (p < 0.0001), while levels remained mainly unchanged in non-responders.

Conclusion

Plasma C4d discriminates LN from active non-renal SLE, correlates with C4d kidney deposits and appears valuable in monitoring responsiveness to various treatments. The C4d/C4 ratio might be superior to C4d alone.

Systemic lupus erythematosus, lupus nephritis and end-stage renal disease: a pragmatic review mapping disease severity and progression

Objective

The understanding of systemic lupus erythematosus (SLE) and lupus nephritis (LN) pathogenesis remains incomplete. This review assessed LN development in SLE, within-LN progression and progression to end-stage renal disease (ESRD).

Methods

A keyword-based literature search was conducted, and 26 publications were included.

Results

Overall, 7–31% of patients had LN at SLE diagnosis; 31–48% developed LN after SLE diagnosis, most within 5 years. Class IV was the most commonly found LN class and had the worst prognosis. Histological transformation occurred in 40–76% of patients, more frequently from non-proliferative rather than proliferative lesions. Cumulative 5- and 10-year ESRD incidences in patients with SLE were 3% and 4%, respectively, and 3–11% and 6–19%, respectively, in patients with SLE and LN.

Conclusions

Elevated serum creatinine was identified as a predictor of worsening disease state, and progression within LN classes and from SLE/LN to ESRD. This review highlights the substantial risk for developing LN and progressing to ESRD amongst patients with SLE.

An Update on the Diagnosis and Management of Lupus Nephritis

PURPOSE OF REVIEW

Update on the diagnosis, treatment, and monitoring of lupus nephritis.

RECENT FINDINGS

The recent criteria enable the earlier classification of lupus nephritis based on kidney biopsy and compatible serology. Treatment of active nephritis includes low-dose intravenous cyclophosphamide or mycophenolate, followed by maintenance immunosuppression. Recent trials have suggested superiority of regimens combining mycophenolate with either calcineurin inhibitor or belimumab, although their long-term benefit/risk ratio has not been determined. Encouraging results with novel anti-CD20 antibodies confirm the effectiveness of B cell depletion. Achievement of low-grade proteinuria (< 700-800 mg/24 h) at 12-month post-induction is linked to favorable long-term outcomes and could be considered in a treat-to-target strategy. Also, repeat kidney biopsy can guide the duration of maintenance immunosuppression. Lupus nephritis has increased cardiovascular disease burden necessitating risk-reduction strategies. An expanding spectrum of therapies coupled with ongoing basic/translational research can lead to individualized medical care and improved outcomes in lupus nephritis.

Deep Phenotyping of Urinary Leukocytes by Mass Cytometry Reveals a Leukocyte Signature for Early and Non-Invasive Prediction of Response to Treatment in Active Lupus Nephritis

Non-invasive biomarkers are necessary for diagnosis and monitoring disease activity in lupus nephritis (LN) to circumvent risks and limitations of renal biopsies. To identify new non-invasive cellular biomarkers in the urine sediment of LN patients, which may reflect kidney inflammation and can be used to predict treatment outcome, we performed in-depth urinary immune cell profiling by mass cytometry. We established a mass cytometric workflow to comparatively analyze the cellular composition of urine and peripheral blood (PB) in 13 patients with systemic lupus erythematosus (SLE) with active, biopsy-proven proliferative LN. Clinical and laboratory data were collected at the time of sampling and 6 months after induction of therapy in order to evaluate the clinical response of each patient. Six patients with different acute inflammatory renal diseases were included as comparison group. Leukocyte phenotypes and composition differed significantly between urine and paired PB samples. In urine, neutrophils and monocytes/macrophages were identified as the most prominent cell populations comprising together about 30%–83% of nucleated cells, while T and B lymphocytes, eosinophils, and natural killer (NK) cells were detectable at frequencies of <10% each. The majority of urinary T cells showed phenotypical characteristics of activated effector memory T cells (EM) as indicated by the co-expression of CD38 and CD69 – a phenotype that was not detectable in PB. Kidney inflammation was also reflected by tissue-imprinted macrophages, which phenotypically differed from PB monocytes by an increased expression of HLA-DR and CD11c. The presence of activated urinary T cells and macrophages could be used for differential diagnosis of proliferative LN forms and other renal pathologies. Most interestingly, the amount of EM in the urine sediment could be used as a biomarker to stratify LN patients in terms of response to induction therapy. Deep immunophenotypic profiling of urinary cells in LN allowed us to identify a signature of activated T cells and macrophages, which appear to reflect leukocytic infiltrates in the kidney. This explorative study has not only confirmed but also extended the knowledge about urinary cells as a future non-invasive biomarker platform for diagnosis and precision medicine in inflammatory renal diseases.

Prediction of prognosis and renal outcome in lupus nephritis

Lupus nephritis (LN) is a severe manifestation of SLE, characterised by subendothelial and/or subepithelial immune complex depositions in the afflicted kidney, resulting in extensive injury and nephron loss during the acute phase and eventually chronic irreversible damage and renal function impairment if not treated effectively. The therapeutic management of LN has improved during the last decades, but the imperative need for consensual outcome measures remains. In order to design trials with success potentiality, it is important to define clinically important short-term and long-term targets of therapeutic and non-therapeutic intervention. While it is known that early response to treatment is coupled with favourable renal outcomes, early predictors of renal function impairment are lacking. The information gleaned from kidney biopsies may provide important insights in this direction. Alas, baseline clinical and histopathological information has not been shown to be informative. By contrast, accumulating evidence of pronounced discrepancies between clinical and histopathological outcomes after the initial phase of immunosuppression has prompted investigations of the potential usefulness of per-protocol repeat kidney biopsies as an integral part of treatment evaluation, including patients showing adequate clinical response. This approach appears to have merit. Hopefully, clinical, molecular or genetic markers that reliably reflect kidney histopathology and portend the long-term prognosis will be identified. Novel non-invasive imaging methods and employment of the evolving artificial intelligence in pattern recognition may also be helpful towards these goals. The molecular and cellular characterisation of SLE and LN will hopefully result in novel therapeutic modalities, maybe new taxonomy perspectives, and ultimately personalised management.

Contribution of Clinically Indicated Repeat Renal Biopsy in Indian Patients with Lupus Nephritis

Background:

Repeat renal biopsy is usually done for lupus nephritis (LN) flare or resistant disease. We analyzed the changes between first and repeat biopsy and the contribution of repeat biopsy on renal outcome in LN patients.

Methods:

This was a retrospective study carried out at a tertiary care center in India. Sixty-two LN patients who underwent repeat biopsy for clinical indications, between January 2012 to December 2016, were included. Clinical and histological parameters at first and second biopsies were compared. Logistic regression analysis was done to determine parameters on repeat biopsy predicting response at last visit.

Results:

Repeat biopsy was done for relapse in 56% and for resistant disease in 44% patients. Seven (13.7%) out of 51 patients with baseline proliferative histology converted to non-proliferative lesion on second biopsy, while 2 (18.2%) out of 11 with baseline non-proliferative lesion converted to proliferative lesion on second biopsy. On repeat biopsy, the presence of endocapillary proliferation decreased, whereas glomerulosclerosis, interstitial fibrosis/tubular atrophy (IFTA), and glomerular basement membrane thickening increased. At the last visit (median follow-up of 38.6 months after first biopsy and 13.8 months after second biopsy), 79% of patients were in remission and 6.5% needed renal replacement therapy. The presence of IFTA >30% and thrombotic microangiopathy (TMA) on second biopsy independently predicted response at last visit.

Conclusion:

In Indian patients with LN, chronicity markers and superimposed membranous pattern increased on repeat biopsy done for clinical indications. The presence of IFTA and TMA on second biopsy predicted response at last visit.

Lupus nephritis

Lupus nephritis (LN) is a form of glomerulonephritis that constitutes one of the most severe organ manifestations of the autoimmune disease systemic lupus erythematosus (SLE). Most patients with SLE who develop LN do so within 5 years of an SLE diagnosis and, in many cases, LN is the presenting manifestation resulting in the diagnosis of SLE. Understanding of the genetic and pathogenetic basis of LN has improved substantially over the past few decades. Treatment of LN usually involves immunosuppressive therapy, typically with mycophenolate mofetil or cyclophosphamide and with glucocorticoids, although these treatments are not uniformly effective. Despite increased knowledge of disease pathogenesis and improved treatment options, LN remains a substantial cause of morbidity and death among patients with SLE. Within 10 years of an initial SLE diagnosis, 5-20% of patients with LN develop end-stage kidney disease, and the multiple comorbidities associated with immunosuppressive treatment, including infections, osteoporosis and cardiovascular and reproductive effects, remain a concern. Clearly, early and accurate diagnosis of LN and prompt initiation of therapy are of vital importance to improve outcomes in patients with SLE.

Management and treatment of glomerular diseases (part 2): conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

In November 2017, the Kidney Disease: Improving Global Outcomes (KDIGO) initiative brought a diverse panel of experts in glomerular diseases together to discuss the 2012 KDIGO glomerulonephritis guideline in the context of new developments and insights that had occurred over the years since its publication. During this KDIGO Controversies Conference on Glomerular Diseases, the group examined data on disease pathogenesis, biomarkers, and treatments to identify areas of consensus and areas of controversy. This report summarizes the discussions on primary podocytopathies, lupus nephritis, anti-neutrophil cytoplasmic antibody-associated nephritis, complement-mediated kidney diseases, and monoclonal gammopathies of renal significance.

Design and application of single-cell RNA sequencing to study kidney immune cells in lupus nephritis

The immune mechanisms that cause tissue injury in lupus nephritis have been challenging to define. The advent of high-dimensional cellular analyses, such as single-cell RNA sequencing, has enabled detailed characterization of the cell populations present in small biopsy samples of kidney tissue. In parallel, the development of methods that cryopreserve kidney biopsy specimens in a manner that preserves intact, viable cells, has enabled the uniform analysis of tissue samples collected at multiple sites and across many geographic areas and demographic cohorts with high-dimensional platforms. The application of these methods to kidney biopsy samples from patients with lupus nephritis has begun to define the phenotypes of both infiltrating and resident immune cells, as well as parenchymal cells, present in nephritic kidneys. The detection of similar immune cell populations in urine suggests that it might be possible to non-invasively monitor immune activation in kidneys. Once applied to large patient cohorts, these high-dimensional studies might enable patient stratification according to patterns of immune cell activation in the kidney or identify disease features that can be used as surrogate measures of efficacy in clinical trials. Applied broadly across multiple inflammatory kidney diseases, these studies promise to enormously expand our understanding of renal inflammation in the next decade.

The Kidney Biopsy in Systemic Lupus Erythematosus: A View of the Past and a Vision of the Future

The kidney biopsy advanced our understanding of kidney disease in systemic lupus erythematosus. It allowed for better recognition and classification of lupus nephritis (LN). Several LN classifications have been devised in an effort to inform treatment decision and predict prognosis, and these are being further updated. In this review, we will examine the role of diagnostic as well as repeat kidney biopsy in the management of LN, including the potential role of molecular interrogation as a step forward beyond conventional histology to guide the discovery of novel biomarkers and a precision medicine approach to the management of LN.