The kidney biopsy in lupus nephritis: is it still relevant?

Clinical management of lupus in the United States: A claims-based analysis

OBJECTIVES

To understand the evaluation and management of patients coded with lupus in the broad clinical community in the United States.

METHODS

Claims data for diagnoses, procedures, medications, and physician specialties were evaluated for three lupus cohorts [lupus nephritis (LN), systemic lupus erythematosus excluding LN (SLE), and cutaneous lupus erythematosus excluding SLE and LN (CLE)] using the EVERSANA claims databases. Identification of patients was based upon the occurrence of lupus-specific codes, with the requirement that a single patient receive a lupus-related ICD code twice within a six-month period.

RESULTS

Using ICD codes, we were able to identify 28,372 patients coded with LN, 82,744 patients coded with SLE, and 13,920 patients coded with CLE, and subsequently evaluate the journey of patients in each group in the year before and after being coded as having a diagnosis of lupus. For the three lupus cohorts, the basis of diagnosis was not always apparent, as clinical features of lupus were not often obtained, autoantibody testing was not usual, biopsies were uncommon and subspecialty involvement was not routine. In addition, a significant increase in laboratory testing, non-lupus diagnoses, emergency department visits and cost during the year before receiving a lupus code suggested uncertainty in disease recognition. Nevertheless, these patients received two separate lupus coding events within a six-month period, supporting a sustained or repeated diagnosis of lupus by the evaluating clinicians. When compared, the three lupus cohorts differed with regard to frequency of laboratory testing, subspecialty care, skin and renal biopsies, and medication management. Moreover, there was an increase in the cost of care of patients coded with lupus compared to a reference patient population both during the year before and after being coded with a diagnosis of lupus.

CONCLUSION

The data present a comprehensive report of the care of patients coded as having a diagnosis of lupus in the United States, including those outside of specialty centers. Despite the unclear basis of diagnosis in some patients, evaluation and management of patients coded as having a diagnosis of lupus in the general care community does not closely follow the recommended guidelines set forth by professional societies.

CaMK4: Structure, physiological functions, and therapeutic potential

Calcium/calmodulin-dependent protein kinase IV (CaMK4) is a versatile serine/threonine kinase involved in various cellular functions. It regulates T-cell differentiation, podocyte function, tumor cell proliferation/apoptosis, β cell mass, and insulin sensitivity. However, the underlying molecular mechanisms are complex and remain incompletely understood. The aims of this review are to highlight the latest advances in the regulatory mechanisms of CaMK4 underlying T-cell imbalance and parenchymal cell mass in multiple diseases. The structural motifs and activation of CaMK4, as well as the potential role of CaMK4 as a novel therapeutic target are also discussed.

Microvascular Density Analysis of Patients with Inactive Systemic Lupus Erythematosus-A Two-Year Follow-Up Optical Coherence Tomography Angiography Study

Background/Objectives: This study aims to investigate the long-term effect of inactive systemic lupus erythematosus (SLE) on the retinal microcirculation measured via optical coherence tomography angiography (OCT-A). Methods: Twenty-four eyes of 24 patients with inactive SLE under hydroxychloroquine (HCQ) therapy were included. The OCT-A data (mainly vessel density (VD) and foveal avascular zone (FAZ) data of the superficial and of the deep capillary plexus (SCP, DCP) and the choriocapillaris (CC)) were analyzed and compared between the baseline examination (t0) and 2 years later (t1). Results: At t1, VD in the whole en face SCP and in the CC was notably reduced compared to t0 (SCP: p = 0.001, CC: p = 0.013). VD in the DCP, CRT and FAZ area showed no difference at t1 compared to t0 (DCP: p = 0.128, FAZ: p = 0.332, CRT fovea: p = 0.296). Correlation analysis between the increase in cumulative doses of HCQ between t0 and t1 and the VD of the whole en face SCP did not show any correlation (Spearman r = 0.062 (95% CI -0.367; 0.477). Conclusions: SLE patients demonstrated a decrease in the retinal VD of the SCP and CC over a 2-year period. There was no correlation with the change in cumulative doses of HCQ. These results suggest an ongoing effect of the disease on the retinal and choriocapillary microcirculation.

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.

Polyneuritis cranialis as a unique initial presentation of juvenile systemic lupus erythematosus: Case report

Cranial neuropathy is a rare presentation in juvenile (j) SLE and being multiple is even rarer. We describe here an adolescent girl presenting with polyneuritis cranialis (PNC) as an initial presentation of SLE which had not been reported before in literature. She presented with symptoms suggestive of bilateral abducent and hypoglossal neuropathy with nerve conduction studies showing partial axonal neuropathy of left facial and accessory nerves, 6 weeks after common cold. The condition was not associated with any other neurological or systemic manifestations nor features of Sjogren's syndrome. Her condition responded well to pulsed methylprednisolone therapy and plasma exchange. After exclusion of the common causes and owing to the initial positive ANA results and mild proteinuria, renal biopsy was taken and revealed histopathological features of class III lupus nephritis for which mycophenolate mofetil was started at 1200 mg per m2. Our case highlights the importance of considering collagen disorders including SLE in the differential diagnosis of children presenting with PNC in order to allow adequate management and proper follow-up.

An interpretable machine learning pipeline based on transcriptomics predicts phenotypes of lupus patients

Machine learning (ML) has the potential to identify subsets of patients with distinct phenotypes from gene expression data. However, phenotype prediction using ML has often relied on identifying important genes without a systems biology context. To address this, we created an interpretable ML approach based on blood transcriptomics to predict phenotype in systemic lupus erythematosus (SLE), a heterogeneous autoimmune disease. We employed a sequential grouped feature importance algorithm to assess the performance of gene sets, including immune and metabolic pathways and cell types, known to be abnormal in SLE in predicting disease activity and organ involvement. Gene sets related to interferon, tumor necrosis factor, the mitoribosome, and T cell activation were the best predictors of phenotype with excellent performance. These results suggest potential relationships between the molecular pathways identified in each model and manifestations of SLE. This ML approach to phenotype prediction can be applied to other diseases and tissues.

Letter to the editor: testing the effectiveness of MyPROSLE in classifying patients with lupus nephritis

Because of the clinical heterogeneity among patients with systemic lupus erythematosus (SLE), developing molecular profiles that predict clinical features can be useful in creating a personalized approach to treatment. Toro-Domínguez et al. created a web tool to aid in therapeutic decision making for clinicians that predicts clinical features associated with SLE from blood transcriptomic data. Specifically, they present a machine learning model that predicts the presence of proliferative nephritis from blood transcriptomics. Here, we report use of the tool in independent datasets and found that it did not perform sufficiently well to consider replacement of the standard kidney biopsy as a diagnostic procedure.

Lupus nephropathy beyond immunosuppression: Searching for nephro and cardioprotection

Renal involvement in systemic lupus erythematosus (SLE) represents one of the most frequent organ manifestations, often leading to end-stage kidney disease (ESKD). Several therapies have been tested in patients with lupus nephritis (LN) to prevent further organ damage. The effectiveness of immunosuppressive therapy as a treatment for LN is abundant, supported by multiple clinical trials that have shown its efficacy in preventing the development of chronic kidney disease (CKD). In addition to immunosuppressive therapy, several traditional and recent therapies aimed at nephroprotection in patients with proteinuric chronic kidney disease are gaining importance in the setting of LN. Thus, immunosuppressive therapy should be accompanied by nephro- and cardioprotective measures to control cardiovascular risk factors and proteinuria to ensure a better renal prognosis. Despite this, the literature on these specific measures is relatively scarce, with recommendations focused on the blockade of the renin-angiotensin-aldosterone system (RAAS). This review explores the pharmacological options available for cardiovascular and renal protection outside the usual treatment schemes.

Scoring personalized molecular portraits identify Systemic Lupus Erythematosus subtypes and predict individualized drug responses, symptomatology and disease progression

OBJECTIVES

Systemic Lupus Erythematosus is a complex autoimmune disease that leads to significant worsening of quality of life and mortality. Flares appear unpredictably during the disease course and therapies used are often only partially effective. These challenges are mainly due to the molecular heterogeneity of the disease, and in this context, personalized medicine-based approaches offer major promise. With this work we intended to advance in that direction by developing MyPROSLE, an omic-based analytical workflow for measuring the molecular portrait of individual patients to support clinicians in their therapeutic decisions.

METHODS

Immunological gene-modules were used to represent the transcriptome of the patients. A dysregulation score for each gene-module was calculated at the patient level based on averaged z-scores. Almost 6100 Lupus and 750 healthy samples were used to analyze the association among dysregulation scores, clinical manifestations, prognosis, flare and remission events and response to Tabalumab. Machine learning-based classification models were built to predict around 100 different clinical parameters based on personalized dysregulation scores.

RESULTS

MyPROSLE allows to molecularly summarize patients in 206 gene-modules, clustered into nine main lupus signatures. The combination of these modules revealed highly differentiated pathological mechanisms. We found that the dysregulation of certain gene-modules is strongly associated with specific clinical manifestations, the occurrence of relapses or the presence of long-term remission and drug response. Therefore, MyPROSLE may be used to accurately predict these clinical outcomes.

CONCLUSIONS

MyPROSLE (https://myprosle.genyo.es) allows molecular characterization of individual Lupus patients and it extracts key molecular information to support more precise therapeutic decisions.

Lupus nephritis in the XXI century

Lupus nephritis (LN) is the most common organ lesion in systemic lupus erythematosus (SLE), developing in 4050% of patients. Due to immunosuppressive therapy, the survival of patients with SLE has increased significantly over the past 50 years, and the proportion of severe kidney damage in the death structure has decreased. However, LN relapses and complications of immunosuppression, accelerated atherogenesis, concomitant diseases lead to the accumulation of organ damage and an increased risk of death. The article consideres the place of kidney damage in the SLE, the risk factors for LN development, the main renal histopathological changes, it identifies a number of issues that need to be addressed to optimize treatment and improve LN long-term outcomes, including, the revision of pathogenetic therapy regimens with restriction of glucocorticosteroids and prescribing drugs with steroid-sparing activity, the integration of new drugs for LN treatment, wider use of modern nephroprotection capabilities.

Clinical and Immunological Biomarkers for Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is characterized by immune system dysfunction and is clinically heterogeneous, exhibiting renal, dermatological, neuropsychiatric, and cardiovascular symptoms. Clinical and physiological assessment is usually inadequate for diagnosing and assessing pathophysiological processes in SLE. Clinical and immunological biomarkers could play a critical role in improving diagnosis, assessment, and ultimately, control of SLE. This article reviews clinical and immunological biomarkers that could diagnose and monitor disease activity in SLE, with and without organ-specific injury. In addition, novel SLE biomarkers that have been discovered through “omics” research are also reviewed.

Clinical and histopathological features and short-term outcomes of lupus nephritis: a prospective study of 100 Egyptian patients

OBJECTIVE

The short-term outcomes of lupus nephritis (LN) are variable and unpredictable among individuals. We aimed to evaluate the clinical and histopathological features and short-term renal outcomes in LN patients.

METHODS

This was a prospective cohort study carried out at nephrology and rheumatology units in Egypt between 2018 and 2019. A total of 100 patients with biopsy-proven LN were studied. Patients were evaluated for response after six months.

RESULTS

The female-to-male ratio was 8.1:1. About 70% of patients were hypertensive at disease onset, with rates for classes I, II, III, IV, V and VI LN being 1%, 7%, 20%, 53%, 14% and 6%, respectively. Among the immunosuppressive drugs used for induction, mycophenolate mofetil (MMF) represented the most commonly used (44%) followed by cyclophosphamide (CYC; 37%). After six months of follow-up, about two thirds of patients achieved remission. There was no significant difference in remission rate between MMF and CYC. On multivariate analysis, serum creatinine (SCr) at presentation was the most significant predictor of renal recovery. According to the receiver operating characteristic curve, the cut-off value of SCr was 1.6 mg/dL, with a sensitivity of 76% and specificity of 71% predicting renal recovery. Repeat renal biopsy was needed in 10 patients; class and treatment strategy changed in 40% and 70% of them, respectively.

CONCLUSION

Our findings in Egyptian LN patients compare favourably with most studies.

Accelerating Medicines Partnership: Organizational Structure and Preliminary Data From the Phase 1 Studies of Lupus Nephritis

The Accelerating Medicines Partnership (AMP) Lupus Network was established as a partnership between the National Institutes of Health, pharmaceutical companies, nonprofit stakeholders, and lupus investigators across multiple academic centers to apply high-throughput technologies to the analysis of renal tissue, urine, and blood from patients with lupus nephritis (LN). The AMP network provides publicly accessible data to the community with the goal of generating new scientific hypotheses and improving diagnostic and therapeutic tools so as to improve disease outcomes. We present here a description of the structure of the AMP Lupus Network and a summary of the preliminary results from the phase 1 studies. The successful completion of phase 1 sets the stage for analysis of a large cohort of LN samples in phase 2 and provides a model for establishing similar discovery cohorts.

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.

Late-onset biopsy-proven lupus nephritis without other associated autoimmune diseases: severity and long-term outcome

Background/Purpose

Lupus nephritis (LN) usually develops within the first years of systemic lupus erythematosus (SLE) onset and rarely after that. There are scarce studies comparing early- versus late-onset nephritis (before versus after five years of SLE diagnosis). The aim of this study was to compare the severity and long-term outcome (after 7 years) in these two, late-onset and early-onset, nephritis groups.

Methods

This study included 93 patients from rheumatology tertiary centers from Brazil and Italy, all of them with biopsy-proven LN with > 7 years follow-up. Patients were divided in two groups: early-onset nephritis ( n = 75) and late-onset nephritis ( n = 18). Clinical and laboratorial data were obtained using a standardized electronic chart database protocol carried out at 1–6 months interval and established in 2000. Patients >50 years or with concomitant autoimmune diseases were excluded. Variables evaluated at the LN presentation were Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), creatinine, albumin, anti-DNA positivity and nephritis class. Variables evaluated at the long-term outcome (after 7 years) were Systemic Lupus International Collaborating Clinics Damage Index (SDI), creatinine, dialysis and mortality.

Results

The average time of LN presentation was 10.94 ± 3.73 years for the late-onset and 1.20 ± 1.60 years for the early-onset group. Their similar nephritis duration (12.44 ± 3.2 versus 13.28 ± 4.03 years, p = 0.41) and comparable mean ages (49.17 ± 9.9 versus 44.11 ± 10.8 years old, p = 0.06) allow a more accurate comparison. Regarding severity, late-onset was similar to early-onset group: SLEDAI (8 (range: 6–22) versus 12 (range: 2–24), p = 0.47), creatinine (1.36 ± 0.94 versus 1.36 ± 1.13 mg/dl, p = 0.99); albumin (2.84 ± 0.65 versus 2.59 ± 0.84 mg/dl, p = 0.30); proteinuria (3.77 ± 2.18 versus 5.01 ± 4.51 g/vol, p = 0.26); proliferative nephritis (44% ( n = 8) versus 60% ( n = 45), p = 0.23). There was also no difference in the long-term outcomes between groups: SDI (1 (range: 0–5) versus 0.5 (range: 0–5), p = 0.27); creatinine (2.04 ± 2.38 versus 1.69 ± 2.26 mg/dl, p = 0.56); dialysis (22% ( n = 4) versus 13% ( n = 10), p = 0.46) and mortality (0% ( n = 0) versus 12% ( n = 9), p = 0.19).

Conclusion

This study provides novel evidence of comparable long-term outcomes between late-onset and early-onset nephritis, which is most likely explained by the observation that at presentation, the clinical, laboratorial and histological features of late-onset and early-onset nephritis are similar. This suggests that there should be no distinct treatment targets and therapeutic interventions for the late- and early-onset groups.

A Predictive Model for Estimation Risk of Proliferative Lupus Nephritis

BACKGROUND

Lupus nephritis (LN) is classified by renal biopsy into proliferative and nonproliferative forms, with distinct prognoses, but renal biopsy is not available for every LN patient. The present study aimed to establish an alternate tool by building a predictive model to evaluate the probability of proliferative LN.

METHODS

In this retrospective cohort with biopsy-proven LN, 382 patients in development cohort, 193 in internal validation cohort, and 164 newly diagnosed patients in external validation cohort were selected. Logistic regression model was established, and the concordance statistics (C-statistics), Akaike information criterion (AIC), integrated discrimination improvement, Hosmer-Lemeshow test, and net reclassification improvement were calculated to evaluate the performance and validation of models.

RESULTS

The prevalence of proliferative LN was 77.7% in the whole cohort. A model, including age, gender, systolic blood pressure, hemoglobin, proteinuria, hematuria, and serum C3, performed well on good-of-fit and discrimination in the development chohort to predict the risk of proliferative LN (291 for AIC and 0.84 for C-statistics). In the internal and external validation cohorts, this model showed good capability for discrimination and calibration (0.84 and 0.82 for C-statistics, and 0.99 and 0.75 for P values, respectively).

CONCLUSION

This study developed and validated a model including demographic and clinical indices to evaluate the probability of presenting proliferative LN to guide therapeutic decisions and outcomes.

Redefining lupus nephritis: clinical implications of pathophysiologic subtypes

Systemic lupus erythematosus (SLE) is associated with a broad spectrum of clinical and immunologic manifestations, of which lupus nephritis is the most common cause of morbidity and mortality. The development of nephritis in patients with SLE involves multiple pathogenic pathways including aberrant apoptosis, autoantibody production, immune complex deposition and complement activation. The 2003 International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification system for lupus nephritis was widely accepted with high intraobserver and interobserver concordance to guide therapeutic strategy and provide prognostic information. However, this classification system is not based on the underlying disease pathophysiology. Some additional lesions that contribute to disease presentation, including glomerular crescents, podocyte injury, tubulointerstitial lesions and vascular injury, should be recognized. Although outcomes for patients with lupus nephritis have improved over the past 30 years, treatment of this disease remains challenging and is best approached on the basis of the underlying pathogenesis, which is only partially represented by the various pathological phenotypes defined by the ISN/RPS classification. Here, we discuss the heterogeneous mechanisms involved in the pathogenesis of lupus nephritis and how improved understanding of underlying disease mechanisms might help guide therapeutic strategies.

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%.

Long-term Outcome of Lupus Nephritis Class II in Argentine Patients: An Open Retrospective Analysis

Background

There is controversy in medical literature over the outcome of patients with lupus nephritis (LN) class II. The aim of this study was to explore the risk of histological transformation (HT) and possible factors related to negative response to treatment in patients with mesangial LN class II.

Methods

A retrospective and multicenter study was carried out that includes patients who had received a diagnosis of LN class II on their first renal biopsy. Creatinine, urine sediment, and proteinuria were recorded at the time of the first biopsy, 6 months, and 1, 2, and 5 years after the first biopsy. Response to treatment, HT, and long-term outcome were evaluated.

Results

Forty-one patients were included. The manifestation at first biopsy was proteinuria greater than 0.5 g/d in 28 patients (68.29%; 8 [28.57%] of 28 patients had nephrotic syndrome), hematuria in 18 patients (43.90%), and deterioration of renal function in 3 patients (7.31%). During the follow-up (median, 8 years; range, 1–35 years), a new biopsy was performed in 18 patients (43.90%), and in 17 patients (17/18 [94.44%]), there was HT. Median time at rebiopsy was 32 months (range, 11–305 months). Of the 18 patients who had a second biopsy, 10 (55.55%) were on hydroxychloroquine versus 100% (19/19) of patients who did not undergo the procedure (P = 0.001). A year after the first renal biopsy, there are data available from 34 patients; of them, 24 patients (70.58%) had achieved response, and 10 patients (29.41%) had no response (NR) (missing data in 7). A higher 24-hour urinary protein at 6 months was predictor of worse outcome at 1 year, with statistical significance difference for the nonresponder group (median proteinuria, 2.3 g/d [range, 0–4.7 g/d]) compared with responders (median proteinuria, 0.28 g/d [range, 0–1.7 g/d]) (P = 0.0133).

In the long-term follow-up (5 years), HT was the main cause of unfavorable outcome and was measured in 78.57% of patients (11/14 patients).

Conclusions

This series shows a high rate of HT in long-term follow-up. Proteinuria at 6 months made it possible to set aside patients who will have an unfavorable outcome in the long term and who will thus benefit from a more aggressive treatment. The results suggest that hydroxychloroquine had a nephroprotective effect.

Preventing the development of SLE: identifying risk factors and proposing pathways for clinical care

Although challenging, developing evidence-based approaches to an early and accurate diagnosis of systemic lupus erythematosus is a key approach to preventing disease and lupus-associated morbidity and mortality. Advances in our understanding of preclinical and incomplete lupus erythematosus have enabled the identification of risk factors that may predict disease and the development of potential strategies aimed at primary prevention. Emerging data support the notion that there is a temporal disease progression from initial asymptomatic autoimmunity (preclinical lupus) through early clinical features of the disease (incomplete lupus erythematosus) to finally becoming fully classifiable systemic lupus erythematosus (complete lupus erythematosus). Here, we review the demographic, clinical, biomarker as well as genetic and environmental features that are reported to increase the risk of disease progression. Based on these risk factors, we propose a clinical care pathway for patients with early disease. We envisage that such a pathway, through early identification of disease, may improve patient outcomes, while reducing health care costs.

Advances in the diagnosis and classification of systemic lupus erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is the prototype of systemic autoimmune diseases. Patients with SLE display a wide spectrum of clinical and serological findings that can mislead and delay the diagnosis. Diagnostic criteria have not been developed yet, whereas several sets of classification criteria are available; however, none of them has 100% sensitivity and 100% specificity, i.e. the hallmark of diagnostic criteria. Nevertheless, classification criteria are often misused as diagnostic criteria, which may affect earliness of diagnosis and lead to more misdiagnosed cases. Areas covered: In this review, we compare old and new classification criteria, discussing their application and pinpointing their limitations in the management of patients. Moreover, we will focus on current and novel biomarkers for SLE diagnosis, highlighting their predictive value and applicability in clinical practice. Expert commentary: SLE diagnosis still represents a challenge, remaining largely based on a clinical judgment. Besides SLE diagnosis, even its classification is still challenging to date. Indeed, although classification of SLE seems to be achieved more frequently with the 2012 SLICC criteria than with the previous 1997 ACR criteria, this last-updated 2012 set might be improved. Notably, diagnostic and classification criteria should be applied to any subject in the world, and consequently they should include immunological variables validated in different populations, which is still an unmet need.

Validation of the Lupus Nephritis Clinical Indices in Childhood-Onset Systemic Lupus Erythematosus

OBJECTIVE

To validate clinical indices of lupus nephritis activity and damage when used in children against the criterion standard of kidney biopsy findings.

METHODS

In 83 children requiring kidney biopsy, the Systemic Lupus Erythematosus Disease Activity Index renal domain (SLEDAI-R), British Isles Lupus Assessment Group index renal domain (BILAG-R), Systemic Lupus International Collaborating Clinics (SLICC) renal activity score (SLICC-RAS), and SLICC Damage Index renal domain (SDI-R) were measured. Fixed effects and logistic models were calculated to predict International Society of Nephrology/Renal Pathology Society (ISN/RPS) class; low-to-moderate versus high lupus nephritis activity (National Institutes of Health [NIH] activity index [AI]) score: ≤10 versus >10; tubulointerstitial activity index (TIAI) score: ≤5 versus >5; or the absence versus presence of lupus nephritis chronicity (NIH chronicity index) score: 0 versus ≥1.

RESULTS

There were 10, 50, and 23 patients with ISN/RPS class I/II, III/IV, and V, respectively. Scores of the clinical indices did not differentiate among patients by ISN/RPS class. The SLEDAI-R and SLICC-RAS but not the BILAG-R differed with lupus nephritis activity status defined by NIH-AI scores, while only the SLEDAI-R scores differed between lupus nephritis activity status based on TIAI scores. The sensitivity and specificity of the SDI-R to capture lupus nephritis chronicity was 23.5% and 91.7%, respectively. Despite being designed to measure lupus nephritis activity, SLICC-RAS and SLEDAI-R scores significantly differed with lupus nephritis chronicity status.

CONCLUSION

Current clinical indices of lupus nephritis fail to discriminate ISN/RPS class in children. Despite its shortcomings, the SLEDAI-R appears best for measuring lupus nephritis activity in a clinical setting. The SDI-R is a poor correlate of lupus nephritis chronicity.

What is damaging the kidney in lupus nephritis?

Despite marked improvements in the survival of patients with severe lupus nephritis over the past 50 years, the rate of complete clinical remission after immune suppression therapy is <50% and renal impairment still occurs in 40% of affected patients. An appreciation of the factors that lead to the development of chronic kidney disease following acute or subacute renal injury in patients with systemic lupus erythematosus is beginning to emerge. Processes that contribute to end-stage renal injury include continuing inflammation, activation of intrinsic renal cells, cell stress and hypoxia, metabolic abnormalities, aberrant tissue repair and tissue fibrosis. A deeper understanding of these processes is leading to the development of novel or adjunctive therapies that could protect the kidney from the secondary non-immune consequences of acute injury. Approaches based on a molecular-proteomic-lipidomic classification of disease should yield new information about the functional basis of disease heterogeneity so that the most effective and least toxic treatment regimens can be formulated for individual patients.

Unmet medical needs in lupus nephritis: solutions through evidence-based, personalized medicine

Lupus nephritis (LN) remains a kidney disease with significant unmet medical needs despite extensive clinical and translational research over the past decade. These include the need to (i) predict the individual risk for LN in a patient with systemic lupus erythematosus, (ii) identify the best therapeutic option for an individual patient, (iii) distinguish chronic kidney damage from active immunologic kidney injury, (iv) develop efficient treatments with acceptable or no side effects and improve the design of randomized clinical trials so that effective drugs demonstrate efficacy. This review discusses the underlying reasons for these unmet medical needs and options of how to overcome them in the future.

Matching Kidneys and Urines: Establishing Noninvasive Surrogates of Intrarenal Events in Primary Glomerulonephritis

Kidney biopsy is the gold standard procedure for providing diagnostic and prognostic information for patients with glomerular-based diseases, however, the utility of this procedure for assessing longitudinal disease activity is limited. The intense search for noninvasive biomarkers of kidney disease activity and injury is driven in large part by the inherent risks of the kidney biopsy procedure and limited information derived from the morphologic description of biopsy findings. Furthermore, gaps in our understanding of the core intrarenal molecular processes underlying the development and progression of glomerular-based diseases has limited the development of effective targeted therapy. In this review, we discuss the potential utility of molecular analysis of the urine to provide a dynamic window into intrarenal molecular and morphologic responses. We focus on molecular analysis of the urine to identify noninvasive surrogate markers of kidney responses, with the goal of using these biomarkers as more sensitive indicators of progression and tissue-level responses to therapeutic interventions in patients with primary glomerulonephritis.