Lupus nephritis: When and how often to biopsy and what does it mean?

A nomogram to predict the risk of proliferative lupus nephritis in patients with systemic lupus erythematosus involving the kidneys

Proliferative lupus nephritis (PLN) is a serious organ-threatening manifestation of systemic lupus erythematosus (SLE) that is associated with high mortality and renal failure. Here, we analyzed data from 1287 SLE patients with renal manifestations, including 780 of which were confirmed as proliferative or non-proliferative LN patients by renal biopsy, divided into a training cohort (547 patients) and a validation cohort (233 patients). By applying a least absolute shrinkage and selection operator (LASSO) regression approach combined with multivariate logistic regression analysis to build a nomogram for prediction of PLN that was then assessed by receiver operating characteristic (ROC) curves, calibration curves, and clinical decision curves (DCA) in both the training and validation cohorts. The area under the ROC curve (AUC) of the model in the training cohort was 0.921 (95% confidence interval (CI): 0.895-0.946), the AUC of internal validation in the training cohort was 0.909 and the AUC of external validation was 0.848 (95% CI: 0.796-0.900). The nomogram showed good performance as evaluated using calibration and DCA curves. Taken together, our results indicate that our nomogram that comprises 12 significantly relevant variables could be clinically valuable to prognosticate on the risk of PLN in SLE, so as to improve patient prognoses.

Machine learning models predicts risk of proliferative lupus nephritis

Objective

This study aims to develop and validate machine learning models to predict proliferative lupus nephritis (PLN) occurrence, offering a reliable diagnostic alternative when renal biopsy is not feasible or safe.

Methods

This study retrospectively analyzed clinical and laboratory data from patients diagnosed with SLE and renal involvement who underwent renal biopsy at West China Hospital of Sichuan University between 2011 and 2021. We randomly assigned 70% of the patients to a training cohort and the remaining 30% to a test cohort. Various machine learning models were constructed on the training cohort, including generalized linear models (e.g., logistic regression, least absolute shrinkage and selection operator, ridge regression, and elastic net), support vector machines (linear and radial basis kernel functions), and decision tree models (e.g., classical decision tree, conditional inference tree, and random forest). Diagnostic performance was evaluated using ROC curves, calibration curves, and DCA for both cohorts. Furthermore, different machine learning models were compared to identify key and shared features, aiming to screen for potential PLN diagnostic markers.

Results

Involving 1312 LN patients, with 780 PLN/NPLN cases analyzed. They were randomly divided into a training group (547 cases) and a testing group (233 cases). we developed nine machine learning models in the training group. Seven models demonstrated excellent discriminatory abilities in the testing cohort, random forest model showed the highest discriminatory ability (AUC: 0.880, 95% confidence interval(CI): 0.835-0.926). Logistic regression had the best calibration, while random forest exhibited the greatest clinical net benefit. By comparing features across various models, we confirmed the efficacy of traditional indicators like anti-dsDNA antibodies, complement levels, serum creatinine, and urinary red and white blood cells in predicting and distinguishing PLN. Additionally, we uncovered the potential value of previously controversial or underutilized indicators such as serum chloride, neutrophil percentage, serum cystatin C, hematocrit, urinary pH, blood routine red blood cells, and immunoglobulin M in predicting PLN.

Conclusion

This study provides a comprehensive perspective on incorporating a broader range of biomarkers for diagnosing and predicting PLN. Additionally, it offers an ideal non-invasive diagnostic tool for SLE patients unable to undergo renal biopsy.

Advances in the pharmacological management of systemic lupus erythematosus

INTRODUCTION

Despite setbacks in clinical trials for systemic lupus erythematosus (SLE), three drugs have been approved for SLE and lupus nephritis (LN) treatment in the past decade. Several ongoing clinical trials, some viewed optimistically by the scientific community, underscore the evolving landscape. Emerging clinical data have established specific therapeutic targets in routine clinical practice for treating SLE, aiming to improve long-term outcomes.

AREAS COVERED

Research related to treatment of SLE and LN is discussed, focusing on randomized clinical trials during the last 5 years and recommendations for the management of SLE published by the European Alliance of Associations for Rheumatology (EULAR), American College of Rheumatology (ACR), Asia Pacific League of Associations for Rheumatology (APLAR), and Pan-American League of Associations of Rheumatology (PANLAR).

EXPERT OPINION

The landscape of SLE and LN treatments is evolving, as new drugs and combination treatment approaches redefine the traditional concepts of induction and maintenance treatment phases. As the therapeutic armamentarium in SLE continues to expand, the research focus is shifting from the imperative for new therapies to advancing our understanding of optimal treatment selection for individual patients, steering toward precision medicine strategies.

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.

Urinary biomarkers associated with podocyte injury in lupus nephritis

The most prevalent and devastating form of organ damage in systemic lupus erythematosus (SLE) is lupus nephritis (LN). LN is characterized by glomerular injury, inflammation, cell proliferation, and necrosis, leading to podocyte injury and tubular epithelial cell damage. Assays for urine biomarkers have demonstrated significant promise in the early detection of LN, evaluation of disease activity, and tracking of reaction to therapy. This is because they are non-invasive, allow for frequent monitoring and easy self-collection, transport and storage. Podocyte injury is believed to be a essential factor in LN. The extent and type of podocyte injury could be connected to the severity of proteinuria, making podocyte-derived cellular debris and injury-related urinary proteins potential markers for the diagnosis and monitoring of LN. This article focuses on studies examining urinary biomarkers associated with podocyte injury in LN, offering fresh perspectives on the application of biomarkers in the early detection and management of LN.

Changes in macrophage infiltration and podocyte injury in lupus nephritis patients with repeated renal biopsy: Report of three cases

BACKGROUND

In this study, we retrospectively analysed macrophage infiltration and podocyte injury in three patients with diffuse proliferative lupus nephritis (LN) who underwent repeated renal biopsy.

CASE SUMMARY

Clinical data of three diffuse proliferative LN patients with different pathological characteristics (case 1 was LN IV-G (A), case 2 was LN IV-G (A) + V, and case 3 was LN IV-G (A) + thrombotic microangiopathy) were reviewed. All patients underwent repeated renal biopsies 6 mo later, and renal biopsy specimens were studied. Macrophage infiltration was assessed by CD68 expression detected by immunohistochemical staining, and an immunofluorescence assay was used to detect podocin expression to assess podocyte damage. After treatment, Case 1 changed to LN III-(A), Case 2 remained as type V LN lesions, and Case 3, which changed to LN IV-S (A), had the worst prognosis. We observed reduced macrophage infiltration after therapy. However, two of the patients with active lesions after treatment still showed macrophage infiltration in the renal interstitium. Before treatment, the three patients showed discontinuous expression of podocin. Notably, the integrity of podocin was restored after treatment in Case 1.

CONCLUSION

It may be possible to reverse podocyte damage and decrease the infiltrating macrophages in LN patients through effective treatment.

Role of [68Ga]-pentixafor positron emission tomography/computed tomography imaging in assessing disease activity in patients with lupus nephritis: A pilot study

OBJECTIVE

The primary objective of our study was to evaluate renal uptake of 68Ga-pentixafor in patients with lupus nephritis. Eighteen patients who satisfied the inclusion criteria were included in our study.

METHODS

The study participants were patients with histopathologically confirmed lupus nephritis who were referred to our department for 68Ga-pentixafor PET/CT scan. We studied the renal images in these patients for uptake patterns based on purely visual as well as semi-quantitative parameters. The visual parameters included uptake relative to the spleen and liver. Semi-quantitative analysis involved the uptake as given by SUVmax. These parameters were correlated with the patients' biochemical as well as histological parameters. Kendall's tau-b test was used to look for an association between renal uptake by visual assessment and histopathological findings. Mean SUVmax values were compared by using the Mann-Whitney U test and a p value < .05 was considered to be statistically significant.

RESULTS

No significant association between the mean renal SUVmax of the bilateral kidneys in pentixafor PET and histopathological class was observed. We did not observe any heterogeneity in uptake patterns that could be attributed to the disease process in our patients.

CONCLUSION

68Ga-pentixafor PET is not a suitable imaging modality for assessment of disease activity in lupus nephritis patients. There is a void in non-invasive testing for patients with this chronic and often disabling condition which calls for further research in this area.

Decipher the Immunopathological Mechanisms and Set Up Potential Therapeutic Strategies for Patients with Lupus Nephritis

Lupus nephritis (LN) is one of the most severe complications in patients with systemic lupus erythematosus (SLE). Traditionally, LN is regarded as an immune complex (IC) deposition disease led by dsDNA-anti-dsDNA-complement interactions in the subendothelial and/or subepithelial basement membrane of glomeruli to cause inflammation. The activated complements in the IC act as chemoattractants to chemically attract both innate and adaptive immune cells to the kidney tissues, causing inflammatory reactions. However, recent investigations have unveiled that not only the infiltrating immune-related cells, but resident kidney cells, including glomerular mesangial cells, podocytes, macrophage-like cells, tubular epithelial cells and endothelial cells, may also actively participate in the inflammatory and immunological reactions in the kidney. Furthermore, the adaptive immune cells that are infiltrated are genetically restricted to autoimmune predilection. The autoantibodies commonly found in SLE, including anti-dsDNA, are cross-reacting with not only a broad spectrum of chromatin substances, but also extracellular matrix components, including α-actinin, annexin II, laminin, collagen III and IV, and heparan sulfate proteoglycan. Besides, the glycosylation on the Fab portion of IgG anti-dsDNA antibodies can also affect the pathogenic properties of the autoantibodies in that α-2,6-sialylation alleviates, whereas fucosylation aggravates their nephritogenic activity. Some of the coexisting autoantibodies, including anti-cardiolipin, anti-C1q, anti-ribosomal P autoantibodies, may also enhance the pathogenic role of anti-dsDNA antibodies. In clinical practice, the identification of useful biomarkers for diagnosing, monitoring, and following up on LN is quite important for its treatments. The development of a more specific therapeutic strategy to target the pathogenic factors of LN is also critical. We will discuss these issues in detail in the present article.

Development of an instrument to predict proliferative histological class in lupus nephritis based on clinical and laboratory data

OBJECTIVES

To compare the correlations of histological class inferences based on clinical manifestations and laboratory tests between rheumatologists and nephrologists, to determine the associations of clinical and laboratory data with histological classes and to develop an instrument that can assist histological class identification in lupus nephritis (LN).

METHODS

Retrospective study based on medical records of 80 systemic lupus erythematosus patients (SLICC criteria classification, 2012) who underwent kidney biopsy between 2010 and 2017. Two rheumatologists and two nephrologists received clinical and laboratory data and answered questions regarding which histological class was expected on kidney biopsy. Kappa (K) coefficient was used to assess agreement between evaluators. A decision tree was constructed using the chi-square interaction detector and logistic regression was performed for the development of the proliferative histological class predictor instrument.

RESULTS

The mean age and disease duration were 33 ± 10.3 years and 11.5 ± 6.7 years, respectively. The level of agreement between the evaluators and kidney biopsy was poor (global K 0.364 ± 0.029; p < .001). Analyzing clinical and laboratory variables as predictors of proliferative histological class, patients with abnormal urinary sediment and positive anti-dsDNA antibodies presented 13.96 and 4.96 times higher risks of presenting class III or IV, respectively (p < 0.001). Our instrument has a sensitivity of 87.8% and specificity of 80%, using abnormal urinary sediment, anti-dsDNA antibodies, and serum creatinine as variables.

CONCLUSIONS

Rheumatologists and nephrologists with experience in treating LN generated evaluations that correlated weakly with kidney biopsy. When kidney biopsy is unavailable or is contraindicated for medical reasons, instruments based on clinical and laboratory predictors may be helpful.

The Value of Cell-Free Circulating DNA Profiling in Patients with Skin Diseases

Liquid biopsy, also known as fluid biopsy or fluid-phase biopsy, is the sampling and analysis of the blood, cerebrospinal fluid, saliva, pleural fluid, ascites, and urine. Compared with tissue biopsy, liquid biopsy technology has the advantages of being noninvasive, having strong repeatability, enabling early diagnosis, dynamic monitoring, and overcoming tumor heterogeneity. However, interest in cfDNA and skin diseases has not expanded until recently. In this review, we present an overview of the literature related to the basic biology of cfDNA in the field of dermatology as a biomarker for early diagnosis, monitoring disease activity, predicting progression, and treatment response.

Silent Lupus Nephritis: Renal Histopathological Profile and Early Detection with Urinary Monocyte Chemotactic Protein 1

Objective

Lupus nephritis (LN) affects almost half of all individuals with systemic lupus erythematosus (SLE). Overt LN (OLN) symptoms might vary from asymptomatic microscopic hematuria to renal failure. However, when there are no clinical or laboratory indicators of renal involvement, some people with silent LN (SLN) may have pathological evidence of renal involvement identified by renal biopsy. Monocyte Chemotactic Protein 1 (MCP-1) is a chemotactic factor that promotes leukocyte migration to the kidney. MCP-1 urine levels (uMCP-1) have been demonstrated to be high in individuals with active LN. The purpose of this study was to discover the occurrence of SLN, as well as the possible variations between overt LN (OLN) and SLN across SLE patients based on the histopathological assessment, as well as the role of uMCP-1 in the early detection of SLN.

Methods

An overall of 144 patients with SLE were included in the current research. Patients were subsequently divided into two groups: individuals who did not have clinical evidence of LN (84 patients) and those with OLN (60 patients). All the patients were subjected to the following investigations: uMCP-1, erythrocyte sedimentation rate (ESR), complement C3 (C3), complement C4 (C4), creatinine, albumin/creatinine ratio (uACR), creatinine clearance, quantitative assessment of proteinuria by 24-hour urine proteinuria (24hr UP) and percutaneous renal biopsy.

Results

Sixty patients from group I (71.4%) showed glomerular lesions on renal biopsy (SLN), and class II was the predominant class. uMCP-1 had a sensitivity of 95.2% and a specificity of 98% in the detection of SLN, and uMCP-1 values were markedly higher in patients with OLN in comparison to SLN.

Conclusion

The actual frequency of SLN may be higher than expected. High levels of uMCP-1 may have warranted the early activity of LN. uMCP-1 can be used as a non-invasive, useful tool for the prediction 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.

Controversies in Systemic Lupus Erythematosus 2021: Changing the Paradigm in the Management of Lupus Nephritis

ABSTRACT

Lupus nephritis (LN) affects about a third of patients with systemic lupus erythematosus. Although the use of conventional therapy has significantly improved the prognosis of LN, the response to treatment remains suboptimal, with high rates of relapse and the occurrence of end-stage kidney disease. The implementation of new diagnostic and treatment strategies aimed at improving these outcomes represents a necessary paradigm shift in the management of LN.Herein, we discuss different points of view regarding these still unresolved issues; these comments represent a debate that took place during the virtual congress of the Pan American League of Associations for Rheumatology (PANLAR) and which was organized by the PANLAR Lupus Study Group, GLADEL (Grupo Latino Americano De Estudio del Lupus) on August 15, 2021.

Belimumab for systemic lupus erythematosus - Focus on lupus nephritis

In recent years, advances in the treatment and management of patients with systemic lupus erythematosus (SLE) have improved their life expectancy and quality of life. However, lupus nephritis (LN) still represents a major life-threatening complication of the disease. Belimumab (BEL), a fully human monoclonal IgG1λ antibody neutralizing soluble B cell activating factor, was approved more than ten years ago as add-on therapy in adults and pediatric patients with a highly active, autoantibody-positive disease despite standard of care (SoC). Recently, the superiority of the addition of BEL to SoC was also demonstrated in LN. In this review, we provide a comprehensive overview of the study landscape, available therapeutic options for SLE (focusing on BEL in renal and non-renal SLE), and new perspectives in the treatment field of this disease. A personalized treatment approach will likely become available with the advent of novel therapeutic agents for SLE and 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.

Urinary galectin-3 binding protein (G3BP) as a biomarker for disease activity and renal pathology characteristics in lupus nephritis

Objective

There is an urgent need to identify novel biomarkers of LN to reflect renal histological changes. This study aims to investigate urinary G3BP levels in LN patients and their association with renal disease activity both clinically and pathologically.

Methods

This is a cross-sectional study. A total of 119 lupus nephritis patients were recruited. Thirty patients with chronic kidney diseases (CKD) and 27 healthy volunteers were also recruited as controls. Urinary G3BP was tested by ELISA. Renal histopathology was reviewed by an experienced renal pathologist. Other clinical variables were collected through chart review.

Results

The levels of uG3BP were significantly increased in active LN patients compared to those in inactive LN (p<0.001), CKD patients (p=0.01), and healthy controls (p<0.001). ROC analysis indicated a good discrimination ability of uG3BP to differentiate active LN from CKD patients (AUC=0.7), inactive LN (AUC=0.76), or healthy controls (AUC=0.87). uG3BP was positively correlated with SLEDAI (ρ=0.352, p<0.001), rSLEDAI (ρ=0.302, p<0.001), and SLICC RAS (ρ=0.465, p<0.001), indicating a role as a biomarker of disease activity. It also correlated with clinical parameters, including 24-h urine protein, ESR, and serum C3 levels. In patients with 24-h urine protein > 3.0 g/24h, uG3BP levels were higher in proliferative LN than in membranous LN (p=0.04). They could discriminate the two pathogenic types of LN (AUC=0.72), and they also positively correlated with AI (ρ=0.389, p=0.008) and scores of hyaline deposits (ρ=0.418, p=0.006). While in patients with 24-h urine protein ≤ 3.0 g/24h, uG3BP levels were not significantly different between proliferative and membranous LN, and there was no apparent relationship between uG3BP levels with AI or with scores of hyaline deposits, but they correlated positively with scores of cellular/fibrocellular crescents (ρ=0.328, p=0.04).

Conclusion

uG3BP is a non-invasive biomarker for clinically and histologically reflecting disease activity. It is associated with active histological changes and can be used as a surrogate biomarker when the renal biopsy is impractical.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02763-4.

Indications and considerations for kidney biopsy: an overview of clinical considerations for the non-specialist

Around 3 million people in the UK have chronic kidney disease and 20% of hospital admissions are complicated by acute kidney injury. Decline in kidney function is not a diagnosis; it is essential to identify and treat underlying causes of acute and chronic kidney disease to either achieve recovery or slow the decline of kidney function. Thorough clinical assessment and simple investigations help determine the category of kidney injury (pre-renal, intrinsic or post-renal) and inform the need for kidney biopsy, which can provide significant information in the evaluation of suspected intrinsic kidney disease, supporting diagnosis, guiding prognosis and management, and identifying disease relapse. The procedure is invasive and not without risk, which although small has the potential to be both organ- and life-threatening. This review outlines roles of kidney biopsy for the non-specialist, with focus of its role in patients with diabetes, lupus, myeloma and in the older patient.

Retrospective review of the clinical and laboratory data in silent lupus nephritis

PURPOSE

To determine the ratio of renal disease necessitating immunosuppressive treatment in lupus patients who are clinically asymptomatic by means of renal disease. It was also examined whether silent lupus nephritis is associated with any of the non-renal clinical findings.

METHODS

All kidney biopsies performed in lupus patients between 1990 and 2009 at the Rheumatology Department of Ege University Faculty of Medicine were retrospectively screened. Among the 258 kidney biopsies screened, 54 had no clinical renal findings but had active disease together with anti-dsDNA positivity and/or hypocomplementemia. Patients were classified into two groups who require and do not require immunosuppressive therapy according to their final pathological results at biopsy. The frequency of serious renal involvement in the sample was calculated. Then subgroups were compared with each other in terms of the clinical and laboratory features using Statistical Package for Social Sciences version 13 software.

RESULTS

Thirteen of the 54 patients (24%) had severe renal involvement requiring immunosuppressant therapy. When the groups were compared to each other, it was found that serositis and hematologic involvement were significantly more frequent in patients who needed immunosuppressive treatment (42.9% versus 10.0%; p = 0.003 and 64.3% versus 37.5; p = 0.039).

CONCLUSION

Even in the absence of clinical renal manifestations, active patients at high risk of renal disease such as hypocomplementemia, anti-ds DNA positivity may have severe renal disease requiring immunosuppressive treatment. Thus, renal biopsy indications in lupus patients should better be revaluated.

One-year renal outcome in lupus nephritis patients with acute kidney injury: a nomogram model

OBJECTIVE

To develop a short-term renal outcome prediction model for acute kidney injury (AKI) in patients with lupus nephritis.

METHODS

Two lupus AKI cohorts from 2 independent centers during 2013-2019 were included, i.e., a derivation cohort from a rheumatology center and a validation cohort from a nephrology center. Clinical characteristics and renal histologic features were obtained. The outcome measurement was the recovery of kidney function within 12-month. Lasso regression was used for feature selection. Prediction models with or without pathology were built and nomogram was plotted. Model evaluation including calibration curve and decision curve analysis was performed.

RESULTS

130 patients and 96 patients were included in the derivation and validation cohorts, of which 82 and 73 patients received renal biopsy, respectively. The prognostic nomogram model without pathology included determinants of SLE duration, days from AKI onset to treatment and baseline creatinine level (C-index 0.85 (95%CI 0.78∼0.91) and 0.79 (95%CI 0.70∼0.88) for the 2 cohorts). Combination of histologic interstitial tubular fibrosis in the nomogram gave an incremental predictive performance (C-index 0.93 vs 0.85, p = 0.039) in the derivation cohort, but failed to improve the performance in the validation cohort (C-index 0.81 vs 0.79, p = 0.78). Decision curve analysis suggested clinical benefit of the prediction models.

CONCLUSION

The predictive nomogram models might facilitate more accurate management for lupus patients with AKI.

History of Proliferative Glomerulonephritis Predicts End Stage Kidney Disease in Pure Membranous Lupus Nephritis

OBJECTIVES

Pure membranous (class V) lupus nephritis (LN) is considered a less aggressive phenotype, but tissue fibrosis and chronic kidney disease may still develop. This study aimed to elucidate the prognostic value of a history of class switch in pure membranous LN.

METHODS

We included LN patients with at least two clinically indicated kidney biopsies. New onset of end stage kidney disease (ESKD) was defined as estimated glomerular filtration rate < 15 ml/min/1.73m2, initiation of dialysis, or kidney transplantation.

RESULTS

Among 220 patients (542 biopsies), 199 (90%) were female, and 118 (54%) were African American, 59 (27%) Caucasian, with median age of 28 years at the first kidney biopsy. Patients with pure class V in a first biopsy converted to proliferative LN in 41% of cases. Pure class V in a repeat biopsy was preceded by proliferative LN in 52%. Trajectory analysis of up to 4 repeat biopsies revealed that ISN class switch may happen at any time, even after multiple biopsies with the same class. New onset ESKD was observed within 2 years in 5/56 (9%) patients with pure class V in a repeat biopsy. All 5 patients had proliferative LN in the first biopsy (log rank p= 0.024).

CONCLUSIONS

The conversion from proliferative to membranous (and vice-versa) is frequent in SLE. It can occur at any time in the course of disease, limiting the prognostic value of the first biopsy. Evidence of prior proliferative LN is key as it is associated with higher risk of ESKD in non-proliferative LN.

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.

Long-term Outcome of Lupus Nephritis: A Single Center Study

Introduction

There is paucity of data on long-term outcome of lupus nephritis (LN) from south India. Our study looks at long term outcomes in patients with biopsy proven LN with terms of response to therapy, flare, mortality, treatment-related complications, outcome and post flare analysis. We also analyzed the factors which predicted the outcome.

Methods

A retrospective observational study was conducted from 2005 to 2012 at St. John's Medical college and hospital, Bangalore. Patients received treatment as per NIH protocol. Patients of LN who regularly visited OPD were included. Statistical analysis was done by using SPSS 19 software.

Results

At end of 84 ± 6 months (N = 59), 38 subjects showed complete remission (CR), 6 partial remission (PR), 3 developed chronic kidney disease, 2 developed end-stage kidney disease (ESKD), and 10 died. In outcome of flare (N = 15), 7 had nephrotic flare, 3 had refractory flare, 3 showed nephritic flare with 2 developing ESKD. Change of LN class was 3 subjects had changed to class II from class IV, 1 to class II from class V, 7 to class III from class IV, 2 to class IV from class V, and 2 to class IV from class VI. Factors predicting poor outcomes were serum creatinine, hypertension at presentation, and failure to achieve remission in 1 year. 7 subjects conceived, of which 4 of them were treated with azathioprine (AZA) and 3 of them who were on mycophenolate mofetil and was changed to AZA. 4 subjects had successful pregnancy outcome, 2 had preeclampsia, and 1 subject had missed abortion.

Conclusion

At end of 84 ± 6 months, patient survival rate was 84%.

The Asia-Pacific League of Associations for Rheumatology consensus statements on the management of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is prevalent in Asia and carries a variable prognosis among patients across the Asia-Pacific region, which could relate to access to health care, tolerability of medications, and adherence to therapies. Because many aspects of SLE are unique among patients from this region, the Asia-Pacific League of Associations for Rheumatology developed the first set of consensus recommendations on the management of SLE. A core panel of 13 rheumatologists drafted a set of statements through face-to-face meeting and teleconferences. A literature review was done for each statement to grade the quality of evidence and strength of recommendation. 29 independent specialists and three patients with SLE were then recruited for a modified Delphi process to establish consensus on the statements through an online voting platform. A total of 34 consensus recommendations were developed. Panellists agreed that patients with SLE should be referred to a specialist for the formulation of a treatment plan through shared decision making between patients and physicians. Remission was agreed to be the goal of therapy, but when it cannot be achieved, a low disease activity state should be aimed for. Patients should be screened for renal disease, and hydroxychloroquine is recommended for all Asian people with SLE. Major organ manifestations of SLE should be treated with induction immunosuppression and subsequently maintenance; options include cyclophosphamide, mycophenolate mofetil, azathioprine, and calcineurin inhibitors, in combination with glucocorticoids. Biologics, combination regimens, plasma exchange, and intravenous immunoglobulins should be reserved for cases of refractory or life-threatening disease. Anticoagulation therapy with warfarin is preferred to the direct oral anticoagulants for thromboembolic SLE manifestations associated with a high-risk antiphospholipid antibody profile.

Immune-Related Urine Biomarkers for the Diagnosis of Lupus Nephritis

The kidney is one of the main organs affected by the autoimmune disease systemic lupus erythematosus. Lupus nephritis (LN) concerns 30-60% of adult SLE patients and it is significantly associated with an increase in the morbidity and mortality. The definitive diagnosis of LN can only be achieved by histological analysis of renal biopsies, but the invasiveness of this technique is an obstacle for early diagnosis of renal involvement and a proper follow-up of LN patients under treatment. The use of urine for the discovery of non-invasive biomarkers for renal disease in SLE patients is an attractive alternative to repeated renal biopsies, as several studies have described surrogate urinary cells or analytes reflecting the inflammatory state of the kidney, and/or the severity of the disease. Herein, we review the main findings in the field of urine immune-related biomarkers for LN patients, and discuss their prognostic and diagnostic value. This manuscript is focused on the complement system, antibodies and autoantibodies, chemokines, cytokines, and leukocytes, as they are the main effectors of LN pathogenesis.

Collagen Type III and VI Remodeling Biomarkers Are Associated with Kidney Fibrosis in Lupus Nephritis

Background

Lupus nephritis (LN) occurs in <40% of patients with SLE. Reliable biomarkers of kidney damage are needed to identify patients with SLE at risk of developing LN to improve screening, treat the disease earlier, and halt progression to kidney failure. Novel biomarkers of extracellular matrix remodeling were evaluated as markers of kidney fibrosis and disease activity in patients with LN.

Methods

Biomarkers of the interstitial collagen type III (PRO-C3) and type VI (PRO-C6) formation and of collagen type III (C3M) degradation were evaluated in the serum and urine of 40 patients with LN, 20 patients with SLE but without LN, 20 healthy controls, and ten biopsy controls (histologic kidney inflammation/damage without SLE). Their association with histologic markers of interstitial fibrosis and tubular atrophy, with inflammatory cell infiltration and with disease activity and chronicity in the patients with LN was assessed.

Results

Despite PRO-C3 (serum) and PRO-C6 (serum and urine) being significantly elevated in patients with LN compared with healthy controls, the markers did not differentiate patients with LN from those with SLE. C3M (urine) levels were not different in LN compared with the other groups. C3M (urine) strongly correlated and PRO-C6 (serum and urine) inversely correlated with kidney function (eGFR). The biomarkers of interstitial collagen turnover PRO-C6 (serum) and C3M (urine) correlated with histologic markers of interstitial fibrosis, tubular atrophy, and monocyte infiltration.

Conclusions

Noninvasive collagen turnover biomarkers are promising tools to identify patients with SLE with kidney histologic modifications.

Lupus Membranous Nephropathy

Background

Lupus membranous nephropathy (LMN) is a rare disease, usually associated with nephrotic syndrome.

Methods

We reviewed the literature by searching for the following terms on Pubmed.gov: lupus nephritis, membranous nephropathy (MN), lupus membranous nephropathy, nephrotic syndrome, and Class V lupus nephritis.

Results

The histology of LMN at light microscopy is similar to that of primary MN. Cases of MN associated with focal or diffuse proliferation are not considered LMN by the International Society of Nephrology/Renal Pathology Society classification. Immunofluorescence study of LMN shows deposits of all immunoglobulins and complement. Tubulo-reticular structures, extraglomerular deposits, subepithelial, and scanty subendothelial deposits can be seen on electron microscopy. Phospholipase A2 receptor deposits are usually but not necessarily absent in LMN. The pathogenesis is still not completely understood. The inflammatory milieu of lupus may favor the development of autoantigens and intraglomerular assembly of immune complexes. These are more often associated with mesangial or endocapillary hypercellular lesions. Alternatively, autoantibodies may bind autoantigens in the glomerular subepithelium, triggering a signaling cascade leading to LMN. A central role in the development of podocyte injury and proteinuria is played by the components of complement C5b-C9. CKD progression in LMN is slow but may be accelerated by the frequency of renal flares. Persistent nephrotic syndrome and/or the frequent use of corticosteroids may lead to a series of life-threatening complications.

Discussion

Treatment of arterial hypertension, dyslipidemia, and diabetes are of paramount importance. Besides specific therapies of these complications, hydroxychloroquine and vitamin D supplementation are recommended. Immunosuppression should be limited to patients with nephrotic proteinuria. The most frequently used drugs are corticosteroids, calcineurin inhibitors, cyclophosphamide, mycophenolate, and rituximab, alone or combined. Early detection and treatment of renal flares is of paramount importance to prevent CKD progression.

Steroid treatment promotes an M2 anti-inflammatory macrophage phenotype in childhood lupus nephritis

BACKGROUND

M1-type proinflammatory macrophages (MΦ) promote glomerular injury in lupus nephritis (LN). However, whether this phenotype is altered by steroid therapy is unclear. Therefore, we investigated the effect of steroid treatment on MΦ phenotype in LN.

METHODS

Patients with LN (7-18 years old) were divided into 2 groups: those with no treatment (N) before biopsy (n = 17) and those who underwent steroid (S) treatment (3-73 days) before biopsy (n = 15). MΦ number and phenotype were assessed by immunofluorescence. In vitro studies used monocyte-derived MΦ from healthy volunteers.

RESULTS

Age at biopsy, urine findings, and kidney function (eGFR) were comparable between the two groups. Biopsies in N group had higher levels of active lesions such as endocapillary hypercellularity, necrosis, and cellular crescent formation (p < 0.05). The total CD68+ MΦ infiltrate was comparable between N and S groups. However, N group had more M1 MΦ (CD68+ CD86+ cells) (p < 0.05) and fewer M2 MΦ (CD68+ CD163+ cells) (p < 0.05), giving a 6-fold increase in the M2/M1 ratio in S vs. N groups. Dexamethasone treatment of cultured MΦ induced upregulation of CD163 expression, increased production of anti-inflammatory (IL-10, IL-19) and profibrotic factors (FGF-22, PDGF), and upregulated the scavenger receptor, stabilin-1. Upregulation of stabilin-1 in CD163+ M2 MΦ was confirmed in biopsies from S group.

CONCLUSIONS

Initial steroid treatment induces MΦ phenotypic change from proinflammatory M1 to anti-inflammatory or profibrotic M2 in LN with acute/active lesions. Although steroid treatment is effective for resolution of M1-medated injury, promotion of fibrotic lesions via M2 MΦ is a potential downside of steroid single therapy in LN.

Association of Urinary Matrix Metalloproteinase 7 Levels With Incident Renal Flare in Lupus Nephritis

OBJECTIVE

Flares of lupus nephritis (LN) are frequent and associated with impaired renal prognosis. One major management obstacle in LN flare is the lack of effective methods to identify at-risk patients earlier in their disease course. This study was undertaken to test the utility of measurement of urinary matrix metalloproteinase 7 (MMP-7) for the dynamic surveillance of renal disease activity and prediction of renal flares in LN.

METHODS

A prospective, 2-stage cohort study was performed in patients with LN. Urinary MMP-7 levels at the time of biopsy were evaluated in 154 patients with newly diagnosed LN in 2 independent cohorts. Urinary MMP-7 levels were assessed for correlation with renal histologic activity. Furthermore, after a minimum period of 12 months of renal disease remission, urinary MMP-7 levels were monitored bimonthly for 2 years in 65 patients with LN. The association between urinary MMP-7 levels and development of LN flare was analyzed.

RESULTS

Urinary MMP-7 levels were elevated in patients with LN. A higher urinary MMP-7 level in LN was associated with greater renal histologic activity. As a marker for identifying LN patients with more severe renal histologic activity (i.e., a histologic activity index of ≥7), the level of urinary MMP-7 outperformed other clinical markers and improved their predictive performance, thus linking urinary MMP-7 levels to renal disease activity. Furthermore, among patients who had follow-up measurements of urinary MMP-7 after achievement of long-term remission of renal disease activity, an elevated urinary MMP-7 level during follow-up was independently associated with an increased risk of LN flare. This elevation in the urinary MMP-7 level hinted at the risk of an LN flare at an earlier time point prior to indications using conventional laboratory measures. Thus, use of the urinary MMP-7 level in conjunction with other clinical measures improved the prognostic value for prediction of an LN flare.

CONCLUSION

Urinary MMP-7 levels in LN are correlated with renal histologic activity. An elevated urinary MMP-7 level detected after achievement of long-term renal disease remission is associated with a higher risk of incident renal flare in patients with LN.

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.

Secondary Membranous Nephropathy. A Narrative Review

Membranous nephropathy (MN) is a common cause of proteinuria and nephrotic syndrome all over the world. It can be subdivided into primary and secondary forms. Primary form is an autoimmune disease clinically characterized by nephrotic syndrome and slow progression. It accounts for ~70% cases of MN. In the remaining cases MN may be secondary to well-defined causes, including infections, drugs, cancer, or autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), urticarial vasculitis, sarcoidosis, thyroiditis, Sjogren syndrome, systemic sclerosis, or ankylosing spondylitis. The clinical presentation is similar in primary and secondary MN. However, the outcome may be different, being often related to that of the original disease in secondary MN. Also, the treatment may be different, being targeted to the etiologic cause in secondary MN. Thus, the differential diagnosis between primary and secondary MN is critical and should be based not only on history and clinical features of the patient but also on immunofluorescence and electron microscopy analysis of renal biopsy as well as on the research of circulating antibodies. The identification of the pathologic events underlying a secondary MN is of paramount importance, since the eradication of the etiologic factors may be followed by remission or definitive cure of MN. In this review we report the main diseases and drugs responsible of secondary MN, the outcome and the pathogenesis of renal disease in different settings and the possible treatments.

Value of monitoring urine ammonia at time of biopsy in patients with lupus nephritis

Objective

Although lupus nephritis (LN) is mostly characterized by glomerular involvement, tubular injury is indispensable in its pathogenesis and progression. The purpose of this study is to examine associations between urinary acidification function and clinical and pathological features in LN.

Methods

A total of 103 patients with renal biopsy-proven LN were included, and clinical parameters and laboratory data were obtained from the medical records. Plasma samples, 24-h urine samples and the urinary acidification function, including urine pH, titratable acid, and ammonia, were collected within 3 days before the day of renal biopsy. The correlations between defects of acid excretion and clinical and pathological features were then assessed. Logistic regression analysis was used to assess factors associated with the presence of nephrotic range proteinuria.

Results

The urine ammonia level was inversely correlated with SLEDAI-2 K scores, rSLEDAI scores, serum creatinine levels and proteinuria, while it was positively correlated with eGFR. And urine titratable acid was only inversely correlated with rSLEDAI scores and proteinuria. Moreover, urine ammonia had significant negative correlations with AI scores, interstitial inflammatory cell infiltration, CI scores, glomerular sclerosis, fibrous crescents, tubular atrophy and interstitial fibrosis. And urine titratable acid was mainly inversely correlated with CI scores. Furthermore, univariate logistic analyses identified that both urine titratable acid and ammonia were correlated with the presence of nephrotic range proteinuria. After the adjustment for chronicity index and eGFR in a multivariate logistic analysis, only urine titratable acid was still identified as an independent risk factor for the occurrence of nephrotic range proteinuria.

Conclusions

Urine ammonia was associated with clinical and pathological features of chronicity and tubulointerstitial disease activity among patients with lupus nephritis. Furthermore, the strong association between urinary protein and titratable acid excretion at the time of kidney biopsy is significant even after adjusting for the chronicity index and eGFR at biopsy.

Renal disorders in rheumatologic diseases: the spectrum is changing (Part 1: connective tissue diseases)

The kidney is frequently involved by autoimmune rheumatic diseases. The renal manifestations may be variable, ranging from asymptomatic proteinuria and microscopic haematuria to nephrotic syndrome and rapidly progressive glomerulonephritis or vasculitis. In a number of cases the kidney involvement is related to the treatment of the original disease and may represent a major cause of morbidity and mortality. Thus, it is important for nephrologists and rheumatologists to remember that dysfunction of the kidney may be part of the primary systemic disorder or consequence of its pharmacotherapy. In the first part of this review we will analyse the kidney involvement in four autoimmune connective tissue diseases: systemic lupus erythematosus, Sjögren syndrome, polymyositis/dermatomyositis, and systemic sclerosis. Renal disease is common in lupus and is a main cause of morbidity and mortality. About 10% of patients with Sjögren syndrome may present interstitial nephritis or, more rarely, glomerulonephritis. Myoglobinuria and acute kidney injury is a frequent complication of polymyositis. Renal disease is one of the most serious complications of systemic sclerosis and may present with a dramatic renal crisis, characterized by malignant hypertension, oligo-anuria, and microangiopathic thrombocytopenic anaemia.

MicroRNA-125a-Loaded Polymeric Nanoparticles Alleviate Systemic Lupus Erythematosus by Restoring Effector/Regulatory T Cells Balance

Systemic lupus erythematosus (SLE), a common lethal autoimmune disease, is characterized by effector/regulatory T cells imbalance. Current therapies are either inefficient or have severe side effects. MicroRNA-125a (miR-125a) can stabilize Treg-mediated self-tolerance by targeting effector programs, but it is significantly downregulated in peripheral T cells of patients with SLE. Therefore, overexpression of miR-125a may have therapeutic potential to treat SLE. Considering the stability and targeted delivery of miRNA remains a major challenge in vivo, we constructed a monomethoxy (polyethylene glycol)-poly(d,l-lactide-co-glycolide)-poly(l-lysine) (mPEG-PLGA-PLL) nanodelivery system to deliver miR-125a into splenic T cells. Results demonstrate that miR-125a-loaded mPEG-PLGA-PLL (PEAL_miR-125a) nanoparticles (NPs) exhibit good biocompatibility and protect miR-125a from degradation, thereby prolonging the circulatory time of miRNA in vivo. In addition, PEAL_miR-125a NPs are preferentially enriched in a pathological spleen and efficiently deliver miR-125a into the splenic T cells in SLE mice models. The PEAL_miR-125a NPs treatment significantly alleviates SLE disease progression by reversing the imbalance of effector/regulatory T cells. Collectively, the PEAL_miR-125a NPs show excellent therapeutic efficacy and safety, which may provide an effective treatment for SLE.

Double Negative B Cell Is Associated With Renal Impairment in Systemic Lupus Erythematosus and Acts as a Marker for Nephritis Remission

Objective: Recent studies on double negative B cells (DN B cells) suggested that they have potential pathogenic roles in systemic lupus erythematosus (SLE). This study aimed to determine the circulating DN B cells in SLE patients and analyzed the clinical significance of this cell subset. Methods: Fifty-seven SLE patients and fifty healthy controls (HCs) were recruited in this study. Among the 57 SLE patients, 25 had lupus nephritis (LN). All patients were followed up for 24 weeks. Peripheral B cell subsets were analyzed by flow cytometry. Results: DN B cells were significantly elevated in the SLE patients, especially in the patients with LN (p < 0.01). DN B showed a positive correlation with 24-h urine protein excretion (24 h-UPE) levels (r = 0.444, p = 0.034) in LN patients, and inversely correlated with evaluated glomerular filtration rate (eGFR) (r = -0.351, p = 0.011). DN B cells had a positive correlation with plasma cells (r = 0.484, p < 0.001) and memory B cells (r = 0.703, p < 0.001). After treatment, decreased DN B cells were associated with LN alleviation (p = 0.002). In the follow-up, the remission rate of LN patients with decreased DN B cells was significantly higher than LN patients with increased DN B cells (83.33 vs. 25.00%, p = 0.030) at week 24. Conclusions: This study suggests that the peripheral DN B cells are positively correlated with the severity of renal damage in LN patients and may potentially be used as a prognostic marker in LN.

A nationwide survey on clinical practice patterns and bleeding complications of percutaneous native kidney biopsy in Japan

Background

Practice patterns and bleeding complications of percutaneous native kidney biopsy (PNKB) have not recently been investigated and the Japanese Society of Nephrology performed a nationwide questionnaire survey in 2018.

Methods

The survey consisted of nine sections about PNKB: (1) general indications; (2) indications for high-risk patients; (3) informed consent; (4) pre-biopsy evaluation; (5) procedures; (6) sedation; (7) post-biopsy hemostasis, bed rest, and examinations; (8) bleeding complications; and (9) specimen processing. A supplementary survey examined bleeding requiring transcatheter arterial embolization (TAE).

Results

Overall, 220 directors of facilities (nephrology facility [NF], 168; pediatric nephrology facility [PF], 52) completed the survey. Indications, procedures, and monitoring protocols varied across facilities. Median lengths of hospital stay were 5 days in NFs and 6 days in PFs. Gauge 14, 16, 18 needles were used in 5%, 56%, 33% in NFs and 0%, 63%, 64% in PFs. Mean limits of needle passes were 5 in NFs and 4 in PFs. The bed rest period was 16–24 h in 60% of NFs and 65% of PFs. Based on 17,342 PNKBs, incidence rates of macroscopic hematuria, erythrocyte transfusion, and TAE were 3.1% (NF, 2.8%; PF, 6.2%), 0.7% (NF, 0.8%; PF, 0%), and 0.2% (NF, 0.2%; PF, 0.06%), respectively. Forty-six percent of facilities processed specimens all for light microscopy, immunofluorescence, and electron microscopy, and 21% processed for light microscopy only. Timing of bleeding requiring TAE varied among PNKB cases.

Conclusion

Wide variations in practice patterns of PNKB existed among facilities, while PNKBs were performed as safely as previously reported.

Electronic supplementary material

The online version of this article (10.1007/s10157-020-01869-w) contains supplementary material, which is available to authorized users.

Initial renal histology and early response predict outcomes of Brazilian lupus nephritis patients

Objective

We analyzed baseline and follow-up characteristics related to poorer renal outcomes in a Brazilian cohort of admixture race patients with lupus nephritis.

Methods

Overall, 280 outpatients with a diagnosis of systemic lupus erythematosus and previous kidney biopsy of lupus nephritis were recruited from August 2015 to December 2018 and had baseline laboratory and histologic data retrospectively analyzed; patients were then followed-up and data were recorded. The main outcome measure was the estimated glomerular filtration rate at last follow-up. Secondary analyses assessed the impact of initial kidney histology and treatment in long-term kidney survival.

Results

Median duration of lupus nephritis was 60 months (interquartile range: 27–120); 40 (14.3%) patients presented progressive chronic kidney disease (estimated glomerular filtration rate <30 and ≥10 ml/min/1.73 m2) or end-stage kidney disease at last visit. Adjusted logistic regression analysis showed that class IV lupus nephritis (odds ratio 14.91; 95% confidence interval 1.77–125.99; p = 0.01) and interstitial fibrosis ≥25% at initial biopsy (odds ratio 5.87; 95% confidence interval 1.32–26.16; p = 0.02), lack of complete or partial response at 12 months (odds ratio 16.3; 95% confidence interval 3.74–71.43; p < 0.001), and a second renal flare (odds ratio 4.49; 95% confidence interval 1.10–18.44; p = 0.04) were predictors of progressive chronic kidney disease. In a Kaplan-Meier survival curve we found that class IV lupus nephritis and interstitial fibrosis ≥25% were significantly associated with end-stage kidney disease throughout follow-up (hazard ratio 2.96; 95% confidence interval 1.3–7.0; p = 0.036 and hazard ratio 4.96; 95% confidence interval 1.9–12.9; p < 0.0001, respectively).

Conclusion

In this large cohort of admixture race patients, class IV lupus nephritis and chronic interstitial damage at initial renal biopsy together with non-response after 1 year of therapy and relapse were associated with worse long-term renal outcomes.

An Exosomal Urinary miRNA Signature for Early Diagnosis of Renal Fibrosis in Lupus Nephritis

For lupus nephritis (LN) management, it is very important to detect fibrosis at an early stage. Urinary exosomal miRNAs profiling can be used as a potential multi-marker phenotyping tool to identify early fibrosis. We isolated and characterised urinary exosomes and cellular pellets from patients with biopsy-proven LN (n = 45) and healthy controls (n = 20). LN chronicity index (CI) correlated with urinary exosomal miR-21, miR-150, and miR-29c (r = 0.565, 0.840, −0.559, respectively). This miRNA profile distinguished low CI from moderate-high CI in LN patients with a high sensitivity and specificity (94.4% and 99.8%). Furthermore, this multimarker panel predicted an increased risk of progression to end-stage renal disease (ESRD). Pathway analysis identified VEGFA and SP1 as common target genes for the three miRNAs. Immunohistochemistry in LN renal biopsies revealed a significant increase of COL1A1 and COL4A1 correlated with renal chronicity. SP1 decreased significantly in the high-CI group (p = 0.002). VEGFA levels showed no differences. In vitro experiments suggest that these miRNA combinations promote renal fibrosis by increasing profibrotic molecules through SP1 and Smad3/TGFβ pathways. In conclusion, a urinary exosomal multimarker panel composed of miR-21, miR-150, and miR-29c provides a non-invasive method to detect early renal fibrosis and predict disease progression in LN.

Anti-α-enolase antibody combined with β2 microglobulin evaluated the incidence of nephritis in systemic lupus erythematosus patients

OBJECTIVE

Anti-α-enolase antibody (Ab) combined with β2 microglobulin (β2-MG) were investigated to predict the incidence of nephritis in systemic lupus erythematosus (SLE) patients.

METHODS

Levels of serum anti-α-enolase Ab and urinary β2-MG were detected in 115 SLE patients, 29 SLE patients with nephritis and 70 healthy controls by ELISA and immunoturbidimetry, respectively. Furthermore, the correlation between anti-α-enolase Ab combined with β2-MG and the incidence of nephritis in SLE patients was evaluated by correlation analysis.

RESULTS

The optical density value of serum anti-α-enolase Ab in SLE patients with nephritis (0.84) was greatly increased compared with SLE patients (0.76) or healthy controls (0.54). Moreover, the levels of urinary β2-MG in SLE patients with nephritis (6.75 mg/L) were increased compared with SLE patients (3.45 mg/L) or healthy controls (1.48 mg/L). There was a positive correlation between the level of anti-α-enolase Ab and β2-MG ( r = 0.754). Furthermore, anti-α-enolase Ab combined with β2-MG for evaluating the incidence of nephritis in SLE patients had the best assessment of the effectiveness (area under the receiver operating characteristic curve (AUC): 92.7%) compared with only anti-α-enolase Ab (AUC: 80.9%) or β2-MG (AUC: 84.5%).

CONCLUSION

These data suggested that anti-α-enolase Ab may be a potential indicator for the prediction of nephritis in SLE patients.

Repeat kidney biopsy for lupus nephritis: an important step forward

There is scant controlled data to guide the use of repeat kidney biopsies to guide therapy in glomerular disease. De Rosa et al. assessed the value of a repeat biopsy during remission in estimating the risk of subsequent relapse of lupus nephritis. They demonstrated the feasibility of a per-protocol repeat biopsy study with prespecified subsequent therapy. Their results will inform the design of future studies of repeat biopsies in lupus nephritis and other kidney diseases.

Changing patterns in clinical-histological presentation and renal outcome over the last five decades in a cohort of 499 patients with lupus nephritis

OBJECTIVES

To evaluate changes in demographic, clinical and histological presentation, and prognosis of lupus nephritis (LN) over time.

PATIENTS AND METHODS

We studied a multicentre cohort of 499 patients diagnosed with LN from 1970 to 2016. The 46-year follow-up was subdivided into three periods (P): P1 1970-1985, P2 1986-2001 and P3 2002-2016, and patients accordingly grouped based on the year of LN diagnosis. Predictors of patient and renal survival were investigated by univariate and multivariate proportional hazards Cox regression analyses. Survival curves were compared using the log-rank test.

RESULTS

A progressive increase in patient age at the time of LN diagnosis (p<0.0001) and a longer time between systemic lupus erythematosus onset and LN occurrence (p<0.0001) was observed from 1970 to 2016. During the same period, the frequency of renal insufficiency at the time of LN presentation progressively decreased (p<0.0001) and that of isolated urinary abnormalities increased (p<0.0001). No changes in histological class and activity index were observed, while chronicity index significantly decreased from 1970 to 2016 (p=0.023). Survival without end-stage renal disease (ESRD) was 87% in P1, 94% in P2% and 99% in P3 at 10 years, 80% in P1 and 90% in P2 at 20 years (p=0.0019). At multivariate analysis, male gender, arterial hypertension, absence of maintenance immunosuppressive therapy, increased serum creatinine, and high activity and chronicity index were independent predictors of ESRD.

CONCLUSIONS

Clinical presentation of LN has become less severe in the last years, leading to a better long-term renal survival.

Autoimmunity in 2016

The number of peer-reviewed articles published during the 2016 solar year and retrieved using the "autoimmunity" key word remained stable while gaining a minimal edge among the immunology articles. Nonetheless, the quality of the publications has been rising significantly and, importantly, acquisitions have become available through scientific journals dedicated to immunology or autoimmunity. Major discoveries have been made in the fields of systemic lupus erythematosus, rheumatoid arthritis, autoimmunity of the central nervous system, vasculitis, and seronegative spondyloarthrithritides. Selected examples include the role of IL17-related genes and long noncoding RNAs in systemic lupus erythematosus or the effects of anti-pentraxin 3 (PTX3) in the treatment of this paradigmatic autoimmune condition. In the case of rheumatoid arthritis, there have been reports of the role of induced regulatory T cells (iTregs) or fibrocytes and T cell interactions with exciting implications. The large number of studies dealing with neuroimmunology pointed to Th17 cells, CD56(bright) NK cells, and low-level TLR2 ligands as involved in multiple sclerosis, along with a high salt intake or the micriobiome-derived Lipid 654. Lastly, we focused on the rare vasculitides to which numerous studies were devoted and suggested that unsuspected cell populations, including monocytes, mucosal-associated invariant T cells, and innate lymphoid cells, may be crucial to ANCA-associated manifestations. This brief and arbitrary discussion of the findings published in 2016 is representative of a promising background for developments that will enormously impact the work of laboratory scientists and physicians at an exponential rate.

Immunosuppressive Effect of B7-H4 Pathway in a Murine Systemic Lupus Erythematosus Model

B7-H4, one of the co-stimulatory molecules of the B7 family, has been shown to play an important role in negatively regulating the adaptive immune response by inhibiting the proliferation, activation, and cytokine production of T cells. In this study, we investigate the role of B7-H4 in development of systemic lupus erythematosus (SLE). We investigated a murine model of SLE using transfer of bone marrow-derived dendritic cells (BMDCs) that were incubated with activated syngeneic lymphocyte-derived DNA. The recipient mouse produced anti-ds-DNA antibodies as well as displayed splenomegaly and lymphadenopathy as shown by significantly increased weights, and the kidneys showed lupus-like pathological changes include urine protein and glomerulonephritis with hyperplasia in glomeruli and increased mesangial cells and vasculitis with perivascular cell infiltration, glomerular deposition of IgG and complement C3. We showed that B7-H4 deficiency in BMDCs could cause greater production of anti-ds-DNA antibodies in transferred mice, and the lymph tissue swelling and the kidney lesions were also exacerbated with B7-H4 deficiency. Treatment with a B7-H4 antagonist antibody also aggravated the lupus model. Conversely, B7-H4 Ig alleviated the lupus manifestations. Therefore, we conclude that B7-H4 is a negative check point for the development of SLE in this murine model. These results suggest that this approach may have a clinical potential in treating human SLE.

Does pregnancy have any impact on long term damage accrual and on the outcome of lupus nephritis?

No data are available about the impact of pregnancy on the long-term outcome of lupus nephritis. Thirty-two women with lupus nephritis with a 10-year follow-up after their first pregnancy ("women who gave birth") and 64 matched controls with the same follow-up and who never had pregnancies ("controls") were compared for the occurrence of SLE flares, chronic kidney disease (CKD), and SLICC/ACR Damage Index (SDI) in the post pregnancy period. The same evaluations were done before and after pregnancy in women who gave birth. The predictors of CKD and damage accrual in the whole population were studied. All patients were Caucasians and had biopsy proven LN. At conception and after 10 years, in both groups, less than 10% of patients had active renal disease (p = ns). Controls had more frequent arterial hypertension (p = 0.025). Between the two groups there was no difference in SLE flares and in CKD free survival curves (p = 0.6 and p = 0.37) during the 10-year follow-up. In both groups, the temporal trend, based on annual evaluation, of glomerular filtration rate and serum creatinine shows a significant decrease and increase respectively. However, the women who gave birth persistently maintained better values of renal function than controls during the whole follow-up (P = 0.00001). There was no difference in the CKD-free survival curves. SDI did not increase significantly in women who gave birth in comparison to controls. All the above mentioned clinical parameters were comparable before and after pregnancy in the women who gave birth. Among the basal clinical characteristics, high serum creatinine and occurrence of SLE flares predicted CKD, whereas low levels of C3, pre-existing damage score, and occurrence of SLE flares predicted SDI increase. Pregnancy was not a predictor of CKD or SDI increase. Carrying a pregnancy during inactive lupus nephritis does not seem to increase the rate of SLE flares, worsen renal prognosis or increase SDI significantly in the very long-term.

The value of repeat biopsy in lupus nephritis flares

Whether a repeat renal biopsy is helpful during lupus nephritis (LN) flares remains debatable. In order to analyze the clinical utility of repeat renal biopsy in this complex situation, we retrospectively reviewed our series of 54 LN patients who had one or more repeat biopsies performed only on clinical indications. Additionally, we reviewed 686 well-documented similar cases previously reported (PubMed 1990-2015).The analysis of all patients reviewed showed that histological transformations are common during a LN flare, ranging from 40% to 76% of cases. However, the prevalence of transformations and the clinical value of repeat biopsy vary when they are analyzed according to proliferative or nonproliferative lesions.The great majority of patients with class II (78% in our series and 77.5% in the literature review) progressed to a higher grade of nephritis (classes III, IV, or V), resulting in worse renal prognosis. The frequency of pathological conversion in class V is lower (33% and 43%, respectively) but equally clinically relevant, since almost all cases switched to a proliferative class. Therefore, repeat biopsy is highly advisable in patients with nonproliferative LN at baseline biopsy, because these patients have a reasonable likelihood of switch to a proliferative LN that may require more aggressive immunosuppression.In contrast, the majority of patients (82% and 73%) with proliferative classes in the reference biopsy (III, IV or mixed III/IV + V), remained into proliferative classes on repeat biopsy. Although rebiopsy in this group does not seem as necessary, it is still advisable since it will allow us to identify the 18% to 20% of patients that switch to a nonproliferative class. In addition, consistent with the reported clinical experience, repeat biopsy might also be helpful to identify selected cases with clear progression of proliferative lesions despite the initial treatment, for whom it is advisable to intensify inmunosuppression. Thus, our experience and the literature data support that repeat biopsy also brings more advantges than threats in this group.The results of the repeat biopsy led to a change in the immunosuppresive treatment in more than half of the patients on average, intensifying it in the majority of the cases, but also reducing it in 5% to 30%.

Acute Kidney Injury Recognition in Low- and Middle-Income Countries

Acute kidney injury (AKI) is increasingly common around the world. Because of the low availability of effective therapies and resource limitations, early preventive and therapeutic measures are essential to decrease morbidity, mortality, and cost. Timely recognition and diagnosis of AKI requires a heightened degree of suspicion in the appropriate clinical and environmental context. In low- and middle-income countries (LMICs), early detection is impaired by limited resources and low awareness. In this article, we report the consensus recommendations of the 18th Acute Dialysis Quality Initiative meeting in Hyderabad, India, on how to improve recognition of AKI. We expect these recommendations will lead to an earlier and more accurate diagnosis of AKI, and improved research to promote a better understanding of the epidemiology, etiology, and histopathology of AKI in LMICs.