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

Extracellular mitochondrial components as new biomarkers for lupus nephritis

Major reason for mortality among systemic lupus erythematosus patients is renal failure due to the deposition of immune complexes in the glomeruli. Being a chronic disease with multiple relapses and remissions across the lifespan, it's important to know the degree of nephritis for diagnosis as well as the long-term clinical management of the patients. Currently, renal biopsy is being used as the gold standard to diagnose and define the stages of the disease. However, renal biopsy being invasive only provides a localized picture of nephritis, and has the risk of bleeding. Additionally, it is also cost-intensive. Hence, a reliable, non-invasive biomarker is required for lupus nephritis. This study has evaluated extracellular mitochondrial components, including cell-free mitochondria, and cell-free mitochondrial DNA as probable biomarkers of the degree of nephritis. Both showed a significant correlation with proteinuria and protein-creatinine ratio. Our study substantiates their usage as clinical biomarkers of nephritis upon their validation in a larger cohort of lupus nephritis patients and other forms of nephritis. Although the current data suggest using cell-free mitochondria as a biomarker of lupus nephritis is better than the cell-free mitochondrial DNA.

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.

Anti-C1q antibodies: a biomarker for diagnosis and management of lupus nephritis. A narrative review

Nephritis is a frequent and severe complication of Systemic Lupus Erythematous (SLE). The clinical course of lupus nephritis (LN) is usually characterized by alternating phases of remission and exacerbation. Flares of LN can lead to deterioration of kidney function, necessitating timely diagnosis and therapy. The presence of autoantibodies against C1q (anti-C1qAb) in the sera of SLE patients has been reported in various studies. Some research suggests that the presence and changes in the titer of anti-C1qAb may be associated with the development of LN, as well as with LN activity and renal flares. However, the exact role of anti-C1qAb in LN remains a subject of debate. Despite variability in the results of published studies, anti-C1qAb hold promise as noninvasive markers for assessing LN activity in SLE patients. Measuring anti-C1qAb levels could aid in diagnosing and managing LN during periods of both inactive disease and renal flares. Nevertheless, larger controlled trials with standardized laboratory assays are necessary to further establish the utility of anti-C1qAb in predicting the reactivation and remission of LN and guiding treatment strategies.

Interstitial fibrosis increases the risk of end-stage kidney disease in patients with lupus nephritis

OBJECTIVE

To evaluate the risk of end-stage kidney disease (ESKD) in lupus nephritis (LN) patients using tubulointerstitial lesion scores.

METHODS

Clinical profiles and histopathological presentations of 151 biopsy-proven LN patients were retrospectively examined. Risk factors of ESKD based on characteristics and scoring of their tubulointerstitial lesions (e.g. interstitial inflammation [II], tubular atrophy [TA], and interstitial fibrosis [IF]) were analyzed.

RESULTS

The mean age of 151 LN patients was 36 years old, and 136 (90.1%) were female. The LN cases examined included: class I/II (n = 3, 2%), class III/IV (n = 119, 78.8%), class V (n = 23, 15.2%), and class VI (n = 6, 4.0%). The mean serum creatinine level was 1.4 mg/dl. Tubulointerstitial lesions were recorded in 120 (79.5%) patients. Prior to receiving renal biopsy, 9 (6.0%) patients developed ESKD. During the follow-up period (mean, 58 months), an additional 47 patients (31.1%) progressed to ESKD. Multivariate analyses identified serum creatinine (hazard ratio [HR]: 1.7, 95% confidence interval [CI]: 1.42-2.03, p < 0.001) and IF (HR: 3.2, 95% CI: 1.58-6.49, p = 0.001) as independent risk factors of ESKD. Kaplan-Meier analysis further confirmed a heightened risk of ESKD associated with IF.

CONCLUSION

Tubulointerstitial involvement is commonly observed in histopathological presentation of LN. However, IF, rather than II, or TA, was found to increase the risk of ESKD in our cohort. Therefore, to predict renal outcome in LN patients prior to adjusting immunosuppressive treatment, degree of IF should be reviewed.

A Comprehensive and Practical Approach to the Management of Lupus Nephritis in the Current Era

Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE) and is one of the leading causes of morbidity and mortality in patients with SLE. It is estimated that up to 60% of individuals with SLE will develop LN, which can manifest at any stage of a patient's life; however, it commonly emerges early in the course of SLE and tends to exhibit a more aggressive phenotype in men compared to women. Black and Hispanic patients are more likely to progress to kidney failure than white patients. LN is characterized by kidney inflammation and chronic parenchymal damage, leading to impaired kidney function and potential progression to kidney failure. This article provides a comprehensive overview of the epidemiology, pathogenesis, clinical presentation, diagnosis, and management of LN, highlighting the importance of early recognition and treatment of LN to prevent progressive, irreversible kidney damage and improve patient outcomes. Additionally, the article discusses current and emerging therapies for LN, including traditional immunosuppressive agents, biological agents, and novel therapies targeting specific pathways involved in LN pathogenesis, to provide a practical guide for clinicians in properly diagnosing LN and determining a patient-centered treatment plan.

Efficacy and safety of Shenqi Dihuang decoction for lupus nephritis: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Lupus Nephritis (LN) is a serious complication of systemic lupus erythematosus (SLE). However, the treatment of lupus nephritis using traditional Chinese medicine remains controversial.

AIM OF THE STUDY

To assess the efficacy and safety of Shenqi Dihuang decoction in the treatment of LN and review the clinical guidelines.

MATERIALS AND METHODS

Six databases (China National Knowledge Infrastructure, Wanfang, PubMed, China Biology Medicine, the Cochrane Library, and Embase) were searched from their inception to September 10, 2022, for randomized controlled trials on the treatment of lupus nephritis using Shenqi Dihuang decoction. We conducted a meta-analysis of random effects using Review Manager 5.4 and assessed the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach.

RESULTS

A total of 15,790 citations were identified, from which 14 eligible randomized controlled trials that enrolled 1002 participants were selected for this systematic review. Low-to-moderate certainty of evidence indicated that when compared with Western medicine, Shenqi Dihuang decoction combined with Western medicine was associated with favorable effects on clinical efficacy (risk ratio (RR) = 1.25, 95% confidence interval (CI): 1.15-1.37), vascular endothelial growth factor (mean difference (MD) = -30.90, 95% CI: -40.18 to -21.63), serum level (MD = -4.81 μmol L-1, 95% CI: -17.14 to 7.53), complement C3 (MD = -0.14 g L-1, 95% CI: -0.23 to -0.04), erythrocyte sedimentation rate (MD = -11.87 mm h-1, 95% CI: -22.01 to -1.73), and SLE disease activity score (MD = -3.38, 95% CI: -4.15 to -2.61), and exhibited a lower risk of infection (RR = 0.2, 95% CI: 0.05-0.90), gastrointestinal reaction (RR = 0.47, 95% CI: 0.17-1.28), and insomnia (RR = 0.29, 95% CI: 0.09-0.92).

CONCLUSIONS

This systematic review provides a potential reference for understanding the efficacy and safety of Shenqi Dihuang decoction combined with Western medicine for treating patients with lupus nephritis. However, owing to the limited quality of the studies included in this review, lack of mycophenolate mofetil control, and high heterogeneity among the included studies, the current findings should be interpreted with caution. Therefore, the efficacy and safety of Shenqi Dihuang decoction in patients with PN still require further verification through future high-quality clinical studies.

Effect of Sustained Clinical Remission on the Risk of Lupus Flares and Impaired Kidney Function in Patients With Lupus Nephritis

Introduction

This retrospective study on patients with biopsy-proven lupus nephritis (LN) aimed to assess the probability of sustained clinical remission (sCR) and to investigate sCR effects on disease flares and impaired kidney function (IKF).

Methods

sCR was defined as clinical-Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) = 0 and estimated glomerular filtration rate (eGFR) >60 ml/min per 1.73 m2 lasting ≥1 year; IKF: eGFR <60 ml/min per 1.73 m2 for >3 months. We analyzed the probability of achieving and maintaining sCR, and the yearly risk of flare. Cox models were used to identify predictors of sCR and IKF with variables analyzed as time-dependent covariates when appropriate.

Results

Of 303 patients followed-up with for 14.8 (interquartile range: 9.8-22) years, 257 (84.8%) achieved sCR. The probability of achieving sCR progressively increased over time reaching 90% at 15 years. Baseline age (hazard ratio [HR]: 1.017; 95% confidence interval [CI]: 0.005-1.029; P = 0.004), hydroxychloroquine intake (HR: 1.385; 95% CI: 1.051-1.825; P = 0.021), and absence of arterial hypertension (HR: 0.699; 95% CI: 0.532-0.921; P = 0.011) were independent predictors of sCR. Among patients who achieved sCR, 142 (55.3%) developed a lupus flare after a median time of 3.6 (2.3-5.9) years. In the remaining 115 patients, sCR persisted for 9.5 (5.8-14.5) years. The probability of sCR to persist at 15 years was 38%. SLE flare risk decreased to 10%, 5%, and 2% in patients with sCR lasting <5, 5 to 10, and >10 years, respectively. At the last observation, 57 patients (18.81%) had IKF. sCR achievement (HR: 0.18, P < 0.001) and its duration (HR: 0.83, P < 0.001) were protective against IKF.

Conclusion

sCR is an achievable target in LN management and protects against IKF. The longer the sCR, the higher the chance of its persistence and the lower the risk of SLE flares.

BCD020 rituximab bioanalog compared to standard treatment in juvenile systemic lupus erythematosus: The data of 12 months case-control study

BACKGROUND

Systemic lupus erythematosus (SLE) is the most frequent and serious systemic connective tissue disease. Nowadays there is no clear guidance on its treatment in childhood. There are a lot of negative effects of standard-of-care treatment (SOCT), including steroid toxicity. Rituximab (RTX) is the biological B-lymphocyte-depleting agent suggested as a basic therapy in pediatric SLE.

AIM

To compare the benefits of RTX above SOCT.

METHODS

The data from case histories of 79 children from the Saint-Petersburg State Pediatric Medical University from 2012 to 2022 years, were analyzed. The diagnosis of SLE was established with SLICC criteria. We compared the outcomes of treatment of SLE in children treated with and without RTX. Laboratory data, doses of glucocorticosteroids, disease activity measured with SELENA-SLEDAI, and organ damage were assessed at the time of initiation of therapy and one year later.

RESULTS

Patients, treated with RTX initially had a higher degree of disease activity with prevalence of central nervous system and kidney involvement, compared to patients with SOCT. One year later the disease characteristics became similar between groups with a more marked reduction of disease activity (SELENA-SLEDAI activity index) in the children who received RTX [-19 points (17; 23) since baseline] compared to children with SOCT [-10 (5; 15.5) points since baseline, P = 0.001], the number of patients with active lupus nephritis, and daily proteinuria. During RTX therapy, infectious diseases had three patients; one patient developed a bi-cytopenia.

CONCLUSION

RTX can be considered as the option in the treatment of severe forms of SLE, due to its ability to arrest disease activity compared to SOCT.

Underlying Mechanisms and Treatment of Hypertension in Glomerular Diseases

PURPOSE OF REVIEW

This review aims to explore the underlying mechanisms that lead to hypertension in glomerular diseases and the advancements in treatment strategies and to provide clinicians with valuable insights into the pathophysiological mechanisms and evidence-based therapeutic approaches for managing hypertension in patients with glomerular diseases.

RECENT FINDINGS

In recent years, there have been remarkable advancements in our understanding of the immune and non-immune mechanisms that are involved in the pathogenesis of hypertension in glomerular diseases. Furthermore, this review will encompass the latest data on management strategies, including RAAS inhibition, endothelin receptor blockers, SGLT2 inhibitors, and immune-based therapies. Hypertension (HTN) and cardiovascular diseases are leading causes of mortality in glomerular diseases. The latter are intricately related with hypertension and share common pathophysiological mechanisms. Hypertension in glomerular disease represents a complex and multifaceted interplay between kidney dysfunction, immune-mediated, and non-immune-mediated pathology. Understanding the complex mechanisms involved in this relationship has evolved significantly over the years, shedding light on the pathophysiological processes underlying the development and progression of glomerular disease-associated HTN, and is crucial for developing effective therapeutic strategies and improving patients' outcomes.

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.

Association of Mitochondrial Pyruvate Carrier with the Clinical and Histological Features in Lupus Nephritis

Background

Mounting evidence suggests that mitochondrial dysfunction contributes to lupus nephritis (LN) pathogenesis. Mitochondrial pyruvate carrier 1 (MPC1) and mitochondrial pyruvate carrier 2 (MPC2) mediating pyruvate transport from the cytoplasm to the mitochondrial matrix, determines the cell survival and cellular energy supply. Here, we aimed to investigate the association of mitochondrial pyruvate carrier expression with the clinical and histological features in LN.

Methods

Patients with biopsy-proven proliferative LN (class III and class IV, n=18) and membranous LN (class V, n=18) were included. Expression of MPC1 and MPC2 were examined by immunohistochemistry. MPC protein levels in the two groups were evaluated by the Student's t-test. Correlation analysis between MPC levels and clinicopathological features was performed by Spearman's rank correlation.

Results

Both MPC1 and MPC2 were exclusively expressed in renal tubules of enrolled LN. Significantly lower MPC1 and MPC2 were observed in patients with proliferative LN compared to membranous LN. In addition, the MPC1 and MPC2 were negatively correlated with SLEDAI-2K score, renal function, and renal pathology activity index.

Conclusion

Both MPC1 and MPC2 were localized in renal tubules, and decreased MPC content was more pronounced in proliferative LN than membranous LN. MPC levels were significantly correlated with renal functions and renal pathology activity.

Is per-protocol kidney biopsy required in lupus nephritis?

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

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

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

Lupus Nephritis in Children: Novel Perspectives

Childhood-onset systemic lupus erythematosus is an inflammatory and autoimmune condition characterized by heterogeneous multisystem involvement and a chronic course with unpredictable flares. Kidney involvement, commonly called lupus nephritis, mainly presents with immune complex-mediated glomerulonephritis and is more frequent and severe in adults. Despite a considerable improvement in long-term renal prognosis, children and adolescents with lupus nephritis still experience significant morbidity and mortality. Moreover, current literature often lacks pediatric-specific data, leading clinicians to rely exclusively on adult therapeutic approaches. This review aims to describe pediatric lupus nephritis and provide an overview of the novel perspectives on the pathogenetic mechanisms, histopathological classification, therapeutic approach, novel biomarkers, and follow-up targets in children and adolescents with lupus nephritis.

Recommendations for Improving Systemic Lupus Erythematosus Care From Black Adults: A Qualitative Study

Importance

Racial inequities in incidence, morbidity, and mortality are a defining feature of systemic lupus erythematosus (SLE). Health care systems are integral to addressing these inequities. However, qualitative evidence that highlights Black SLE care experiences is limited.

Objective

To identify opportunities for improving SLE care based on the experiences and perspectives of Black adults with SLE.

Design, Setting, and Participants

In this qualitative study, an interpretive description approach was used and data were analyzed using inductive thematic analysis. Semistructured interviews with Black adults in Michigan who were diagnosed with SLE were conducted. Interviews occurred from November 2, 2021, to July 19, 2022, and data analysis occurred from May 6, 2022, to April 12, 2023.

Main Outcomes and Measures

Deidentified transcripts from the interviews were analyzed to develop themes that focused on opportunities to improve quality of care and symptom management.

Results

The participants included 30 Black adults with SLE (97% women; mean age, 41 years; range, 18-65 years). Four main themes were identified: (1) awareness of SLE signs and symptoms before diagnosis (participants emphasized delays in diagnosis and how knowledge concerning SLE could be limited in their families and communities); (2) patient-clinician interactions (participants faced discrimination in health care settings and talked about the value of coordinated and supportive health care teams); (3) medication adherence and health effects (participants experienced a range of adverse effects from medications that treat SLE and described how monitoring medication use and efficacy could inform tailored care approaches); and (4) comprehensive care plans after diagnosis (participants reported persistent pain and other symptoms despite treatment). In the context of disease management, participants emphasized the importance of behavioral change and the negative impact of social risk factors.

Conclusions and Relevance

The findings of this qualitative study suggest how limited information about SLE, experiences of racism, treatment regimens, and social risk factors may affect Black people with SLE. Future research should further engage and include Black communities within the context of treatment and intervention development to reduce racial inequities.

Flares in Lupus Nephritis: Risk Factors and Strategies for Their Prevention

PURPOSE OF REVIEW

Discuss the prognostic significance of kidney flares in patients with lupus nephritis, associated risk factors, and possible preventative strategies.

RECENT FINDINGS

Recently performed clinical trials and observational cohort studies underscore the high frequency of relapses of kidney disease, following initial response, in patients with proliferative and/or membranous lupus nephritis. Analysis of hard disease outcomes such as progression to chronic kidney disease or end-stage kidney disease, coupled with histological findings from repeat kidney biopsy studies, have drawn attention to the importance of renal function preservation that should be pursued as early as lupus nephritis is diagnosed. In this respect, non-randomized and randomized evidence have suggested a number of factors associated with reduced risk of renal flares such as attaining a very low level of proteinuria (< 700-800 mg/24 h by 12 months), using mycophenolate over azathioprine, adding belimumab to standard therapy, maintaining immunosuppressive/biological treatment for at least 3 to 5 years, and using hydroxychloroquine. Other factors that warrant further clarification include serological activity and the use of repeat kidney biopsy to guide the intensity and duration of treatment in selected cases. The results from ongoing innovative studies integrating kidney histological and clinical outcomes, together with an expanding spectrum of therapies in lupus nephritis, are expected to facilitate individual medical care and long-term disease and patient prognosis.

SGLT2 inhibitors alleviated podocyte damage in lupus nephritis by decreasing inflammation and enhancing autophagy

OBJECTIVES

The protective role of sodium glucose cotransporter 2 (SGLT2) inhibitors in renal outcomes has been revealed by large cardiovascular outcome trials among patients with type 2 diabetes. However, the effect of SGLT2 inhibitors on lupus nephritis (LN) and its underlying mechanisms remain unknown.

METHODS

We applied empagliflozin treatment to lupus-prone MRL/lpr mice to explore the renal protective potential of SGLT2 inhibitors. An SGLT2 knockout monoclonal podocyte cell line was generated using the CRISPR/Cas9 system to examine the cellular and molecular mechanisms.

RESULTS

In MRL/lpr mice treated with empagliflozin, the levels of mouse anti-dsDNA IgG-specific antibodies, serum creatinine and proteinuria were markedly decreased. For renal pathology assessment, both the glomerular and tubulointerstitial damages were lessened by administration of empagliflozin. The levels of SGLT2 expression were increased and colocalised with decreased synaptopodin in the renal biopsy samples from patients with LN and MRL/lpr mice with nephritis. The SGLT2 inhibitor empagliflozin could alleviated podocyte injury by attenuating inflammation and enhanced autophagy by reducing mTORC1 activity. Nine patients with LN treated with SGLT2 inhibitors with more than 2 months of follow-up showed that the use of SGLT2 inhibitors was associated with a significant decrease in proteinuria from 29.6% to 96.3%. Moreover, the estimated glomerular filtration rate (eGFR) was relatively stable during the treatment with SGLT2 inhibitors.

CONCLUSION

This study confirmed the renoprotective effect of SGLT2 inhibitors in lupus mice, providing more evidence for non-immunosuppressive therapies to improve renal function in classic autoimmune kidney diseases such as LN.

Renal Histopathology Associated With Kidney Failure and Mortality in Patients With Lupus Nephritis: A Long-Term Real-World Data Study

OBJECTIVE

Lupus nephritis (LN), a common manifestation of systemic lupus erythematosus, is associated with a higher risk of kidney failure and death. The renal pathology of LN helps elucidate the severity of inflammation and the extent of irreversible damage. We aimed to identify histologic variables that correlate with risks of kidney failure and mortality.

METHODS

Between 2006 and 2019, a total of 526 patients with LN were enrolled. Renal pathology was classified according to the International Society of Nephrology/Renal Pathology Society classification. Components of activity and chronicity indices were analyzed to determine which variables correlated with an increased risk of kidney failure and death, with the adjustment of potential confounders.

RESULTS

During the follow-up period (median 7.5, IQR 3.5-10.7 years), 58 patients progressed to kidney failure and 64 died. In the multivariate Cox regression analysis, tubular atrophy (hazard ratio [HR] 2.28, 95% CI 1.66-3.14) and tubulointerstitial inflammation (HR 3.13, 95% CI 1.34-7.33) predicted kidney failure. The renal outcome was even worse if tubular atrophy and tubulointerstitial inflammation coexisted (10-year kidney survival rate: 63.22%). The presence of cellular crescents was associated with an increased risk of death in male patients with LN (HR 1.91, 95% CI 1.02-3.57), whereas the presence of fibrous crescents predicted death in female patients with LN (HR 5.70, 95% CI 1.61-20.25).

CONCLUSION

Histologic variables of renal biopsy in LN could be regarded as prognostic indicators for kidney failure and mortality.

Urine L-selectin reflects clinical and histological renal disease activity and treatment response in lupus nephritis across multi-ethnicity

Objective

There is an urgent need for novel biomarkers in lupus nephritis (LN). We report a non-invasive urinary biomarker, L-selectin, in two independent multi-ethnic cohorts.

Methods

uL-selectin was tested cross-sectionally in a Chinese cohort (n=255) and a US cohort (n=219) of SLE patients and controls using ELISA. A longitudinal cohort includes 20 active Chinese LN patients.

Results

uL-selectin was significantly increased in active LN patients compared to active non-renal SLE, inactive LN, inactive non-renal SLE, chronic kidney disease patients, and healthy controls. uL-selectin positively correlated with global and renal disease activities as well as histological activity index and chronicity index (CI). Low uL-selectin was an independent predictor for high CI. During follow-up, uL-selectin levels decreased significantly in the complete renal remission group.

Conclusion

uL-selectin is a novel biomarker of disease activity and renal histopathology in LN across multiple ethnicities. It also reflects treatment response in LN patients during follow up.

Lupus nephritis or not? A simple and clinically friendly machine learning pipeline to help diagnosis of lupus nephritis

OBJECTIVE

Diagnosis of lupus nephritis (LN) is a complex process, which usually requires renal biopsy. We aim to establish a machine learning pipeline to help diagnosis of LN.

METHODS

A cohort of 681 systemic lupus erythematosus (SLE) patients without LN and 786 SLE patients with LN was established, and a total of 95 clinical, laboratory data and 17 meteorological indicators were collected. After tenfold cross-validation, the patients were divided into training set and test set. The features selected by collective feature selection method of mutual information (MI) and multisurf were used to construct the models of logistic regression, decision tree, random forest, naive Bayes, support vector machine (SVM), light gradient boosting (LGB), extreme gradient boosting (XGB), and artificial neural network (ANN), the models were compared and verified in post-analysis.

RESULTS

Collective feature selection method screens out antistreptolysin (ASO), retinol binding protein (RBP), lupus anticoagulant 1 (LA1), LA2, proteinuria and other features, and the hyperparameter optimized XGB (ROC: AUC = 0.995; PRC: AUC = 1.000, APS = 1.000; balance accuracy: 0.990) has the best performance, followed by LGB (ROC: AUC = 0.992; PRC: AUC = 0.997, APS = 0.977; balance accuracy: 0.957). The worst performance is naive Bayes model (ROC: AUC = 0.799; PRC: AUC = 0.822, APS = 0.823; balance accuracy: 0.693). In the composite feature importance bar plots, ASO, RF, Up/Ucr, and other features play important roles in LN.

CONCLUSION

We developed and validated a new and simple machine learning pathway for diagnosis of LN, especially the XGB model based on ASO, LA1, LA2, proteinuria, and other features screened out by collective feature selection.

Mortality and causes of death in systemic lupus erythematosus over the last decade: Data from a large population-based study

OBJECTIVE

To assess mortality rates (MRs), standardized mortality ratios, and causes of death in systemic lupus erythematosus (SLE) in a population-based study.

METHODS

We analyzed linked administrative health databases of the Veneto Region (Italy, 4,900,000 residents). SLE was defined by any hospital diagnosis or healthcare copayment exemption for SLE. We analyzed mortality from January 1st, 2012, until December 31st, 2021. MRs per 1000 were stratified by year, sex, and age group. Standardized mortality ratios were derived by comparing MRs of the general regional population. Causes of death were coded using the ICD-10 coding system and they were grouped in: SLE, infectious diseases, cardiovascular diseases (CVD), cancer, or others.

RESULTS

Among 4283 SLE prevalent cases, 603 deaths occurred, corresponding to an average annual standardized MR of 18.6 per 1000 person/year (95% CI 17.0-20.2). Out of 1092 incident SLE patients, 90 died with a peak in the first year after diagnosis (MR 26.5 per 10,000 person/month). Standardized mortality ratio was 2.65 (95% CI 2.13-3.26) overall, and highest among younger patients (<45 years: 5.59, 95% CI 2.05-12.4). Five- and 8-year survival were 91% and 89%, respectively. About half of the deaths had CVD or cancer as underlying cause, whereas infections were less frequently reported.

CONCLUSIONS

Although the medium-term survival since diagnosis is good, SLE mortality is still higher than that of the general population, especially in youngest patients. Nowadays, CVD seems to be the major cause of deaths in SLE, whereas infections account for a low proportion of deaths, at least in Western countries.

Elevated serum levels of human epididymis protein 4 in adult patients with proliferative lupus nephritis

Background

This study aimed to access whether serum human epididymis protein 4 (HE4) level could identify lupus nephritis (LN) pathological classes in adults and children.

Methods

The serum HE4 levels of 190 healthy subjects and 182 patients with systemic lupus erythematosus (SLE) (61 adult-onset LN [aLN], 39 childhood-onset LN [cLN], and 82 SLE without LN) were determined using Architect HE4 kits and an Abbott ARCHITECT i2000SR Immunoassay Analyzer.

Results

Serum HE4 level was significantly higher in the aLN patients (median, 85.5 pmol/L) than in the patients with cLN (44 pmol/L, P < 0.001) or SLE without LN (37 pmol/L, P < 0.001), or the healthy controls (30 pmol/L, P < 0.001). Multivariate analysis showed that serum HE4 level was independently associated with aLN. Stratified by LN class, serum HE4 level was significantly higher in the patients with proliferative LN (PLN) than in those with non-PLN, and this difference was found only in aLN (median, 98.3 versus 49.3 pmol/L, P = 0.021) but not in cLN. Stratified by activity (A) and chronicity (C) indices, the aLN patients with class IV (A/C) possessed significantly higher serum HE4 levels than those with class IV (A) (median, 195.5 versus 60.8 pmol/L, P = 0.006), and this difference was not seen in the class III aLN or cLN patients.

Conclusion

Serum HE4 level is elevated in patients with class IV (A/C) aLN. The role of HE4 in the pathogenesis of chronic lesions of class IV aLN needs further investigation.

Predictors of treatment outcomes in lupus nephritis with severe acute kidney injury and requirement of dialytic support

INTRODUCTION/OBJECTIVES

Acute kidney injury (AKI) with the requirement of kidney replacement therapy (KRT) portends a poor prognosis for kidney function in lupus nephritis (LN). This study evaluated the kidney function recovery rates, the rates of reinitiation of KRT, and factors associated with these outcomes in LN.

METHOD

All consecutive patients hospitalized for LN with KRT requirement between 2000 and 2020 were included. Their clinical and histopathologic characteristics were retrospectively registered. The outcomes and associated factors were evaluated by multivariable Cox regression analysis.

RESULTS

Among 140 patients, 75 (54%) recovered kidney function, with recovery rates of 50.9% and 54.2% by 6 and 12 months of therapy. The factors associated with a lower probability of recovery included a previous history of LN flares, worse eGFR and higher proteinuria at presentation, immunosuppression with azathioprine, and hospitalizations within 6 months of therapy initiation. There was no difference in the kidney function recovery rates between mycophenolate and cyclophosphamide treatment schemes. Out of 75 patients who recovered kidney function, 37 (49%) reinitiated KRT, with KRT reinitiation rates of 27.2% and 46.5% by 3 and 5 years. Seventy-three (52%) patients had at least one hospitalization within 6 months of initial therapy, 52 (72%) of them secondary to infectious events.

CONCLUSIONS

Approximately 50% of patients with LN and KRT requirement recover kidney function within 6 months. The risk-to-benefit ratio decisions may be aided by clinical and histological factors. These patients require close follow-up as ≈50% of those who recover kidney function will reinitiate dialysis in the long term. Key Points • Approximately 50% of patients with severe acute lupus nephritis with the need for kidney replacement therapy requirement recover their kidney function. • The factors associated with a lower probability of recovery of kidney function include a previous history of LN flares, worse eGFR and higher proteinuria at presentation, immunosuppression with azathioprine, and hospitalizations within 6 months of therapy initiation. • Patients who recover kidney function will require close follow-up as around 50% of them will eventually reinitiate kidney replacement therapy.

Treatment of lupus nephritis: consensus, evidence and perspectives

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

Efficacy and Safety of Biologic Agents for Lupus Nephritis: A Systematic Review and Meta-analysis

OBJECTIVES

The aim of this study was to examine the effect and safety of biological agents for lupus nephritis (LN).

METHODS

PubMed, EMBASE, and the Cochrane Library databases were searched from their inception up to November 2021. The outcomes were overall response, complete remission, proteinuria, renal activity index, and adverse events (AEs). Only randomized controlled trials (RCTs) were included.

RESULTS

Nine RCTs (1645 patients) were included. The RCTs evaluated abatacept (n = 2), belimumab (n = 1), obinutuzumab (n = 1), atacicept (n = 1), IL-2 (n = 1), ocrelizumab (n = 1), and rituximab (n = 2). The use of biological agents was associated with higher likelihoods of achieving an overall response (relative risk [RR], 1.26; 95% confidence interval [CI], 1.15-1.39; p < 0.001; I2 = 14.3%; pQ = 0.301) and a complete response (RR, 1.33; 95% CI, 1.16-1.54; p < 0.001; I2 = 41.8%; pQ = 0.056). The use of biological agents was not associated with improvements in the urinary protein-to-creatinine ratio (weighted mean difference, 3.83; 95% CI, -3.71 to 11.38; p = 0.319; I2 = 99.4%; pQ < 0.001). The use of biological agents in patients with LN was also not associated with an increased risk of any AEs (RR, 1.01; 95% CI, 0.98-1.04; p = 0.519; I2 = 0.0%; pQ = 0.533), serious AEs (RR, 0.95; 95% CI, 0.82-1.09; p = 0.457; I2 = 0.0%; pQ = 0.667), grade >3 AEs (RR, 0.91; 95% CI, 0.67-1.22; p = 0.522; I2 = 0.0%; pQ = 0.977), infections (RR, 1.09; 95% CI, 0.99-1.20; p = 0.084; I2 = 0.0%; pQ = 0.430), and deaths (RR, 0.67; 95% CI, 0.36-1.24; p = 0.200; I2 = 0.0%; pQ = 0.439). The meta-regression analysis showed that follow-up duration and the sample size did not influence the complete response rate, whereas publications in 2012 to 2014 influence the rate compared with 2015 to 2020.

CONCLUSIONS

Biological agents seem to be effective and safe for managing patients with LN.

[Lupus nephritis: from diagnosis to treatment]

Renal involvement in systemic lupus erythematosus (SLE), so-called lupus nephritis (LN), is one of the most frequent organ manifestations with an incidence of approximately 40-60%. It is not uncommon for renal involvement to be the initial manifestation of SLE or to occur in the first 5-10 years after diagnosis of SLE. Urinalysis is useful in screening for the presence of LN, demonstrating proteinuria or active sediment with acanthocytes. Histologic confirmation of LN, and thus the LN class present, is currently the gold standard for confirming the diagnosis. In addition, knowledge of the LN class is a relevant component of adequate treatment planning in SLE patients with LN. In particular, early diagnosis and rapid response to therapy are of prognostic importance for the preservation of renal function as well as morbidity and mortality of the mostly young patients at the time of initial diagnosis. Thus, the focus of therapy is to achieve complete remission, as well as to avoid active disease phases. Due to a complex pathogenesis and at the same time a very heterogeneous clinical presentation, with six different histological classes of LN, there are different therapeutic targets. This in turn results in a significant expansion of the study landscape in the field of LN with an increasing understanding of the signaling pathways and influencing factors, and fortunately in a growing armamentarium of available targeted therapy options. Simultaneously, new insights into drug therapy to inhibit progression of chronic renal disease are opening up supportive therapy options that can further improve preservation of renal function.

Kidney Biopsy in Pregnant Women with Glomerular Diseases: Focus on Lupus Nephritis

Despite significant improvements of renal and obstetrical management, pregnancies in women with glomerular diseases and with lupus nephritis continue to be associated with increased complications both for the mother and the fetus as compared to those of pregnancies in healthy women. To reduce the risk of these complications, planning pregnancy in a phase of stable remission of the underlining disease is necessary. A kidney biopsy is an important event in any phase of pregnancy. A kidney biopsy can be of help during counselling before pregnancy in cases of incomplete remission of the renal manifestations. In these situations, histological data may differentiate active lesions that require the reinforcement of therapy from chronic irreversible lesions that may increase the risk of complications. In pregnant women, a kidney biopsy can identify new-onset systemic lupus erythematous (SLE) and necrotizing or primitive glomerular diseases and distinguish them from other, more common complications. Increasing proteinuria, hypertension, and the deterioration of kidney function during pregnancy may be either due to a reactivation of the underlying disease or to pre-eclampsia. The results of the kidney biopsy suggest the need to initiate an appropriate treatment, allowing the progression of the pregnancy and the fetal viability or the anticipation of delivery. Data from the literature suggest avoiding a kidney biopsy beyond 28 weeks of gestation to minimize the risks associated with the procedure vs. the risk of preterm delivery. In case of the persistence of renal manifestations after delivery in women with a diagnosis of pre-eclampsia, a renal kidney assessment allows the final diagnosis and guides the therapy.

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.

Peripheral Eosinophil Count Associated with Disease Activity and Clinical Outcomes in Hospitalized Patients with Lupus Nephritis

INTRODUCTION

The aim of this study was to evaluate the association of peripheral eosinophil (EOS) count with disease activity and kidney outcomes in lupus nephritis (LN) patients.

METHODS

A total of 453 hospitalized and biopsy-proven LN patients at our hospital from 2006 to 2013 were enrolled, of which 388 patients had repeated measurements of EOS. Relationships were explored between average EOS and disease activity at baseline, using the systemic lupus erythematosus disease activity (SLEDAI) and activity index (AI) on kidney biopsy. Follow-up data were available through December 2016. The primary outcome measure was a composite of doubling of serum creatinine and end-stage kidney disease after a median follow-up of 51 months.

RESULTS

The mean age of the enrolled 388 LN patients was 33.1 ± 10.8 years old, and 335 (86%) were female. The median average peripheral EOS count was 0.033 (0.015-0.057) ×109/L. Mean AI and SLEDAI score were 6.8 ± 2.5 and 14.9 ± 5.4, respectively. Logistic regression models showed that decreased average EOS was independently associated with higher AI (≥6) and higher SLEDAI (≥15) (odds ratio [OR] 0.93, 95% confidence interval [CI] 0.90-0.97; and OR 0.96, 95% CI: 0.93-0.99, respectively). There was a parabolic relationship between average EOS and the primary outcome, with hazard ratio (HR) > 1 for both levels ≤0.033 and >0.16 × 109/L.

CONCLUSION

Lower EOS count was independently associated with severe disease activity and kidney progression in LN.

Consensus document of the Spanish Group for the Study of the Glomerular Diseases (GLOSEN) for the diagnosis and treatment of lupus nephritis

A significant number of patients with systemic lupus erythematosus (between 20% and 60% according to different reported series) develop lupus nephritis in the course of its evolution, which directly influences their quality of life and vital prognosis. In recent years, the greater knowledge about the pathogenesis of systemic lupus and lupus nephritis has allowed relevant advances in the diagnostic approach and treatment of these patients, achieving the development of drugs specifically aimed at blocking key pathogenic pathways of the disease. Encouragingly, these immunomodulatory agents have shown in well-powered, randomized clinical trials good clinical efficacy in the medium-term, defined as proteinuria remission and preservation of kidney function, with an acceptable safety profile and good patient tolerability. All this has made it possible to reduce the use of corticosteroids and other potentially more toxic therapies, as well as to increase the use of combined therapies. The present consensus document carried out by the Glomerular Diseases Working Group of the Spanish Society of Nephrology (GLOSEN), collects in a practical and summarized, but rigorous way, the best currently available evidence about the diagnosis, treatment, and follow-up of lupus nephritis patients, including cases of special situations, with the main objective of providing updated information and well-founded clinical recommendations to treating physicians, to improve the diagnostic and therapeutic approach to our patients.

Response to therapy at 6 months predicts long-term renal outcome in lupus nephritis with poor kidney function

OBJECTIVE

It is unclear whether aggressive treatment would benefit lupus nephritis (LN) with poor renal function, which has been excluded from most clinical trials. We aimed at demonstrating their clinicopathological features and prognosis.

METHODS

From August 2012 to December 2018, patients with active LN with poor renal function (estimated glomerular filtration rate (eGFR) between 15 and 59 mL/min/1.73 m²) receiving induction therapy were included. Complete response (CR) was defined as proteinuria <0.5 g/24 hours, while partial response (PR) was defined as ≥50% proteinuria reduction to subnephrotic levels (<3.5 g/24 hours), with (near) normal eGFR. The primary outcome was end-stage renal disease (ESRD). The significant variables were selected via the least absolute shrinkage and selection operator method to construct prediction models for ESRD and treatment response.

RESULTS

A total of 107 patients were included. At 6 months, 18.7%, 38.3% and 43.0% of patients achieved CR, PR and no response (NR), respectively. During a median follow-up of 60 months, 40.2% ended up with reduced renal function (eGFR <60 mL/min/1.73 m²) and 14.0% progressed to ESRD. The proportions of NR at 6 months were significantly higher in these patients compared with those with recovered renal function (p<0.001). In multivariable analysis, baseline eGFR ≤33 mL/min/1.73 m² (HR 3.499, 95% CI 1.044 to 11.730), fibrous crescent (HR 3.439, 95% CI 1.029 to 11.490) and NR at 6 months (HR 17.070, 95% CI 2.155 to 135.240) independently predicted ESRD (C-index 0.911, 95% CI 0.866 to 0.956). Further, baseline hypertension (HR 2.517, 95% CI 0.820 to 8.580), SLE duration>3 months (2.517, 1.012-7.226) and chronicity index (HR 1.757, 95% CI 1.371 to 2.414) predicted NR at 6 months (C-index 0.833, 95% CI 0.756 to 0.910).

CONCLUSIONS

In patients with LN with poor renal function, no response at 6 months predicts a poor long-term renal outcome.

B Cell Kinetics upon Therapy Commencement for Active Extrarenal Systemic Lupus Erythematosus in Relation to Development of Renal Flares: Results from Three Phase III Clinical Trials of Belimumab

Renal flares constitute major determinants of poor prognosis in people living with systemic lupus erythematosus (SLE). The aim of the present study was to investigate changes in B cell subsets in relation to renal flares upon initiation of standard therapy (ST) plus belimumab or placebo in patients with SLE. Using data from the BLISS-76, BLISS-SC, and BLISS Northeast Asia trials, we investigated associations of relative to baseline rapid (through week 8) and early (through week 24) percentage changes in circulating CD19⁺ B cell subsets characterised through flow cytometry, anti-dsDNA antibodies, and complement levels with the occurrence of renal flares over one year. Patients who developed renal flares showed more prominent rapid decreases in CD19⁺CD20⁺CD138⁺ short-lived plasma cells (-50.4% vs. -16.7%; p = 0.019) and CD19⁺CD20^-CD27^bright plasmablasts (-50.0% vs. -29.9%; p = 0.020) compared to non-flaring patients, followed by a subsequent return. Less prominent rapid reductions in CD19⁺CD27^-CD24^brightCD38^bright transitional B cells (-42.9% vs. -75.0%; p = 0.038) and CD19⁺CD20^-CD138⁺ peripheral long-lived plasma cells (-11.3% vs. -29.2%; p = 0.019) were seen in belimumab-treated-but not placebo-treated-patients who developed renal flares compared to belimumab-treated patients who did not. Rapid and early changes in anti-dsDNA or complement levels showed no clear association with renal flares. In summary, a rapid drop followed by a subsequent return in circulating short-lived plasma cells and plasmablasts upon treatment for active extra-renal SLE portended renal flares, indicating a need for therapeutic adjustments in patients showing such B cell patterns. Rapid decreases in transitional B cells and peripheral long-lived plasma cells upon belimumab therapy commencement may signify a greater protection against renal flares. B cell kinetics may prove useful in early drug evaluation.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

OBJECTIVE

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

METHOD

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

RESULT

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

CONCLUSION

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

Persistent Isolated C3 Hypocomplementemia as a Strong Predictor of End-Stage Kidney Disease in Lupus Nephritis

Introduction

Proliferative lupus nephritis (LN) progresses to end-stage kidney disease (ESKD) in roughly 10% of the cases despite treatment. Other than achieving <0.8 g/24h proteinuria at 12 months after treatment, early biomarkers predicting ESKD or death are lacking. Recent studies encompassing not only LN have highlighted the central role of the alternative complement pathway (ACP), with or without histological evidence of thrombotic microangiopathy (TMA), as a key promotor of renal death.

Methods

We assessed whether persistent isolated C3 hypocomplementemia (PI-LowC3), that is not accompanied by C4 hypocomplementemia, 6 months after kidney biopsy, is associated with an increased risk of death or ESKD in proliferative LN.

Results

We retrospectively followed-up 197 patients with proliferative LN (51 with PI-LowC3) for a median of 4.5 years (interquartile-range: 1.9-9.0), 11 of whom died and 22 reached ESKD. After adjusting for age, gender, ethnicity, hypertension, mycophenolate, or cyclophosphamide use, PI-LowC3 was associated with a hazard ratio [HR] of the composite outcome ESKD or death of 2.46 (95% confidence interval [CI]: 1.22-4.99, P = 0.012). These results were confirmed even after controlling for time-varying estimated glomerular filtration rate (eGFR) measurements in joint longitudinal-survival multiple regression models. After accounting for the competing risk of death, PI-LowC3 patients showed a strikingly increased risk of ESKD (adjusted HR 3.41, 95% CI: 1.31-8.88, P = 0.012).

Conclusion

Our findings support the use of PI-LowC3 as a low-cost readily available biomarker, allowing clinicians to modify treatment strategies early in the course of disease and offering a rationale for complement blockade trials in this particularly at-risk subgroup of LN patients.

Predictors of Early Response, Flares, and Long-Term Adverse Renal Outcomes in Proliferative Lupus Nephritis: A 100-Month Median Follow-Up of an Inception Cohort

Objective: To define predictors of response, time to response, flares, and long-term renal outcome in an inception cohort of proliferative lupus nephritis (PLN). Methods: We included 100 patients (80% female; mean age 31 ± 13 years) with biopsy-proven PLN (III, IV, III/IV + V). Clinical, laboratory, histological and therapeutical parameters were recorded at baseline, 6, 9, 12, 18, 24, 36, 72 months, time of flare, and last follow-up visit. Logistic and Cox-regression models were applied. Results: After induction treatment (69% received cyclophosphamide (CYC) and 27% mycophenolic acid (MPA)), partial (PR) or complete (CR) response was achieved in 59% (26% CR, 33% PR) and 67% (43% CR, 24% PR) of patients at 3 and 6 months, respectively; median time to PR was 3 months (IQR 5) and median time to CR was 6 months (IQR 9). Baseline proteinuria <1.5 g/day correlated with a shorter time to CR (HR 1.77) and with CR at 3, 6, and 9 months (OR 9.4, OR 5.3 and OR 3.7, respectively). During 100-month median follow-up, 33% of patients had ≥1 renal flares (median time: 38 months). Proteinuria >0.8 g/day at 12 months was associated with a higher risk of flares (OR 4.12), while MPA and mixed classes with lower risk (OR 0.14 and OR 0.13, respectively). Baseline proteinuria >2 g/day and 12-month proteinuria >0.8 g/day correlated with a shorter time to flare (HR 2.56 and HR 2.57, respectively). At the end of follow-up, 10% developed stage 3–4 chronic kidney disease (CKD), and 12% end-stage renal disease (ESRD). Twelve-month proteinuria >0.8 g/day (OR 10.8) and interstitial fibrosis/tubular atrophy >25% (OR 7.7) predicted CKD or ESRD at last visit. Conclusions: Baseline proteinuria <1.5 g/day predicted time to CR. Twelve-month proteinuria >0.8 g/day correlated with flares (ever) and time to flare and, along with baseline interstitial fibrosis/tubular atrophy >25%, predicted CKD or ESRD at the last visit.

Severe lupus nephritis in the present days

Lupus nephritis (LN) is one of the most frequent and severe organ manifestations of systemic lupus erythematosus (SLE) that is a chronic autoimmune disease. Despite improvement in patient and renal prognosis, the disease continued to be associated with a high rate of end stage kidney disease. Along the last decades, it seems that the epidemiology of LN and its clinical presentation have progressively changed. The forms with renal insufficiency at presentation seem to have progressively reduced in developed countries in favour of more mild clinical presentations with urinary abnormalities only. To this clinical change does not correspond a less severe histological lesions, in fact, the extent of active lesions at kidney biopsy are unchanged, whereas chronic lesions are becoming less frequent and less severe. Meanwhile, new types of severe LN defined by the variable association of demographic, clinical, histological characteristics at diagnosis or during the follow-up are gradually emerging and require attention in assessing the therapy and prognosis. During the last years, randomized controlled trials have reported the efficacy of new drugs in association with standard therapy to improve the rate of short- and medium-term renal response. One of the advantages is that these results were obtained with reduced dosage of corticosteroids whose protracted use is associated with increase of chronic organ damage. Optimization of therapeutical strategies, tailored on the demographic clinical and histological characteristics, with combination of old and new drugs are urgently needed for severe LN.

Efficiency of Disease and Disease Activity Diagnosis Models of Systemic Lupus Erythematosus Based on Protein Array Analysis

Background

Systemic lupus erythematosus (SLE) has become increasingly common in the clinic and requires complicated evidence of both clinical manifestations and laboratory examinations. Additionally, the assessment and monitoring of lupus disease activity are challenging. We hope to find efficient biomarkers and establish diagnostic models of SLE.

Materials and Methods

We detected and quantified 40 proteins using a quantitative protein array of 76 SLE patients and 21 healthy controls, and differentially expressed proteins were screened out by volcano plot. Logistic regression analysis was used to recognize biomarkers that could be enrolled in the disease diagnosis model and disease activity diagnosis model, and a receiver operating characteristic (ROC) curve was drawn to evaluate the efficiency of the model. A nomogram was depicted for convenient and visualized application of our models in the clinic. Decision curves and clinical impact curves were also plotted to validate our models.

Results

The protein levels of TNF RII, BLC, TNF RI, MIP-1b, eotaxin, MIG, MCSF, IL-8, MCP-1, and IL-10 showed significant differences between patients with SLE and healthy controls. TNF RII and MIP-1b were included in the SLE diagnosis model with logistic regression analysis, and the value of the area under the ROC curve (AUC) was 0.914 (95% confidence interval (CI), 0.859-0.969). TNF RII, BLC, and MIP-1b were enrolled in the disease activity diagnosis model, and the AUC value was 0.823 (95% CI 0.729-0.916). Both of the models that we established showed high efficiency. Additionally, the three protein biomarkers contained in the disease activity distinguish model provided additional benefit to conventional biomarkers in predicting active lupus.

Conclusions

The disease diagnosis model and disease activity diagnosis model that we developed based on protein array chip results showed high efficiency in differentiating patients with SLE from healthy controls and recognizing SLE patients with high disease activity, and they have also been validated. This implied that they might greatly benefit clinical decisions and the treatment of SLE.

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.

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.

Infection profile and risk factors for mortality in patients with end-stage renal disease attributable to systemic lupus erythematosus: a two-center integrated study

Objective

Renal impairment is a significant complication of systemic lupus erythematosus (SLE). Additionally, infection in patients with end-stage renal disease (ESRD) attributable to SLE is common, and it increases the risk of mortality. This study explored the infection profile and risk factors for mortality in patients with ESRD attributable to SLE.

Methods

In this retrospective, observational study of 125 hospitalized patients, demographic, clinical, laboratory, treatment, and prognosis data were retrieved and analyzed.

Results

The 125 cases included 98 pulmonary infections (78.4%), 14 urinary infections (11.2%), and 13 intestinal infections (10.4%). Twenty-six patients died within 1 month after enrollment. Univariate Cox regression and Kaplan–Meier analyses revealed several possible indicators potentially influencing patient survival. Furthermore, multivariate Cox regression analysis identified a higher SLE Disease Activity Index-2000 score, recent higher-dose glucocorticoid use, hypertension, and catheter indwelling as risk factors for higher mortality.

Conclusions

Infections were common in patients with advanced SLE and ESRD, and several risk factors might increase the risk of mortality. Once infection is identified, empiric antibiotics should be initiated immediately, and subsequent antibiotics should be applied per the results of drug sensitivity testing to clear the infection.

Cross-species transcriptome analysis for early detection and specific therapeutic targeting of human lupus nephritis

Objectives

Patients with lupus nephritis (LN) are in urgent need for early diagnosis and therapeutic interventions targeting aberrant molecular pathways enriched in affected kidneys.

Methods

We used mRNA-sequencing in effector (spleen) and target (kidneys, brain) tissues from lupus and control mice at sequential time points, and in the blood from 367 individuals (261 systemic lupus erythematosus (SLE) patients and 106 healthy individuals). Comparative cross-tissue and cross-species analyses were performed. The human dataset was split into training and validation sets and machine learning was applied to build LN predictive models.

Results

In murine SLE, we defined a kidney-specific molecular signature, as well as a molecular signature that underlies transition from preclinical to overt disease and encompasses pathways linked to metabolism, innate immune system and neutrophil degranulation. The murine kidney transcriptome partially mirrors the blood transcriptome of patients with LN with 11 key transcription factors regulating the cross-species active LN molecular signature. Integrated protein-to-protein interaction and drug prediction analyses identified the kinases TRRAP, AKT2, CDK16 and SCYL1 as putative targets of these factors and capable of reversing the LN signature. Using murine kidney-specific genes as disease predictors and machine-learning training of the human RNA-sequencing dataset, we developed and validated a peripheral blood-based algorithm that discriminates LN patients from normal individuals (based on 18 genes) and non-LN SLE patients (based on 20 genes) with excellent sensitivity and specificity (area under the curve range from 0.80 to 0.99).

Conclusions

Machine-learning analysis of a large whole blood RNA-sequencing dataset of SLE patients using human orthologs of mouse kidney-specific genes can be used for early, non-invasive diagnosis and therapeutic targeting of LN. The kidney-specific gene predictors may facilitate prevention and early intervention trials.

Renal response and its predictive factors of lupus nephritis: a 2-year real-world study of 56 hospital-based patients

OBJECTIVES

Our aim was to evaluate the renal response rate of patients with lupus nephritis (LN) undergoing standard treatment during a 2-year follow-up and to investigate its predictive factors.

METHODS

A prospective cohort study that enrolled 56 clinically diagnosed LN patients with urinary protein positivity was carried out. All patients underwent standard treatment. All patients were followed up at 6-month intervals for 2 years. Data on renal response and clinical characteristics were collected and analyzed.

RESULTS

Among 56 patients, 27 (48.2%) and 13 (23.2%) patients achieved complete renal response (CR) and partial renal response (PR) at 6 months after induction therapy, respectively, and 42 (75.0%) and 4 (7.1%) patients developed CR and PR at 2 years. Among patients who achieved PR at 6 months, 90.0% achieved CR at 24 months, while only 37.5% of the patients who were unresponsive at 6 months achieved CR. In the multivariable Cox proportional-hazards model, female (OR 6.51, 95% CI 1.23-34.52, p = 0.028), disease duration (OR 0.84, 95% CI 0.73-0.98, p = 0.021), achieving PR within 6 months (OR 8.09, 95% CI 2.06-31.73, p = 0.003), and urine protein/creatinine ratio (UPCR) (OR 0.998, 95% CI 0.996-1.000, p = 0.025) were found to be predictive factors of CR.

CONCLUSION

A total of 48.2% of patients achieved CR at 6 months of induction therapy, and the response rates gradually increased to 60.7%, 64.3%, and 75.0% at 12, 18, and 24 months. Besides, female, disease duration, partial response within 6 months, and UPCR were predictive factors for a complete renal response. Key Points • We evaluate the renal response rates in Chinese patients with lupus nephritis in the real world for 2 years. • A total of 48.2% and 75.0% of patients achieved a complete response after standard treatment for 6 months and 2 years. • Female, disease duration, partial response within 6 months, and UPCR are predictors of complete renal response.

Gain-of-function TLR7 and loss-of-function A20 gene variants identify a novel pathway for Mendelian lupus and lupus nephritis

Systemic lupus erythematosus (SLE) is a chronic and inflammatory autoimmune disease of unknown origin that may cause kidney disease, i.e. lupus nephritis (LN). Within a wider trend towards an expanding field of genetic causes of kidney disease, two recent reports have emphasized the role of Mendelian autoimmune disorders in causing LN both in children and in young adults. Loss-of-function (LOF) variants of tumor necrosis factor alpha–induced protein 3 (TNFAIP3) and gain of function (GOF) variants of Toll-like receptor 7 (TLR7) cause SLE and LN, respectively. Interestingly, both genes regulate the same signaling route, as A20, the protein encoded by TNFAIP3, inhibits nuclear factor ĸB (NF-ĸB) activation while TLR7 promoted NF-ĸB activation. Moreover, TNFAIP3 and TLR7 variants are relatively frequent, potentially contributing to polygenic risk for LN. Finally, they both may be expressed by kidney cells, potentially contributing to the severity of kidney injury in persons who have already developed autoimmunity. The fact that both genes regulate the same pathway may lead to novel therapeutic approaches targeting the shared molecular pathway.

Long-term outcome and predictors of long-term outcome in patients with lupus nephritis managed at a tertiary hospital in Mumbai

AIM

Study the long-term outcome of the patients with LN and identify the baseline factors that can predict the long-term outcome of these patients.

METHODS

All biopsy-proven LN patients who attended our regular 'lupus nephritis' clinic from 2013 to 2021 were studied. Data of these patients were collected from the hospital patient records. Standard therapy was given as per the KDIGO guidelines, and the renal response was evaluated according to KDIGO outcome criteria. Cox' regression analysis was used to determine predictors of chronic kidney disease (persistent doubling of serum creatinine with creatinine ≥1.5 mg%). Kaplan-Meier analysis was used for renal survival.

RESULTS

Eighty patients with at least 1 year of follow-up were included. Median age of onset was 24 years (IQR18-35). Median follow up was 6.5 years (IQR 3-10). World Health Organisation renal biopsy profile was Class I 1(1.2 %), Class II 6(7.5 %), Class III 9(11.2 %), Class IV 36(45 %), Class V 18(22.5 %) and Mixed Class IV + V 10 (12%). Complete remission was achieved in 63.75%, 70 % and 66.6% patients at 1, 2 and 5 years, respectively. Survival with normal renal function was 88.5 %, 85.8% and 60 % at 5, 10 and 15 years, respectively. Risk factors for poor outcome on univariate analysis were presence of Raynaud's phenomena-hazard ratio(HR) 7.78 (CI 1.944-31.207; p < .004), baseline hypertension-HR 5.356 (CI 1.479-19.403; p < .011), tubulointerstitial involvement-HR 1.076 (CI 1.032-1.222; p < .001), time to complete response-HR 1.036 (CI 1.036-1.067; p < .02 ), serum creatinine at 6 months HR 10.51 (CI 2.19-50.39; p < .003), failure to achieve complete response at 2 years HR 6.271 (CI 1.567-25.092; p < .009) and the number of nephritic flares HR 1.868(CI 1.103-3.164 ; p < .02). Renal relapses were quite common, with 1.8 flares per 10 patient-years of follow up. Infection was the most common cause of death, with bacterial lower respiratory infections and pulmonary tuberculosis being the most common.

CONCLUSIONS

Apart from conventional risk factors, other predictive factors like the presence of Raynaud's phenomenon, tubulointerstitial fibrosis and tubular atrophy on kidney biopsy, and initial response to induction therapy by 6 months have a significant impact on the long-term outcome in patients with LN.

Differences and similarities of proliferative and non-proliferative forms of biopsy-proven lupus nephritis: Single centre, cross-disciplinary experience

OBJECTIVE

We aimed to compare clinical features, outcomes, treatments, and to define the predictive factors of complete renal response (CRR) in patients with proliferative and non-proliferative lupus nephritis (LN).

METHODS

Patients with systemic lupus erythematosus (SLE) followed between 2014 and 2020 at Hacettepe University Hospitals and who had a kidney biopsy were the subject of the study. One hundered and sixteen patients' kidney biopsies reported as LN were evaluated retrospectively. Clinical characteristics and laboratory values at the time of kidney biopsy, histopathological forms of LN, and renal response (complete or partial) were recorded. We analyzed the association between CRR rates during the 2-year follow-up after induction therapy and the predictive factors for CRR.

RESULTS

Of 116 (93 females, 23 males) patients, 95 (81.9%) were in the proliferative group (class III and IV) and 21 (18.1%) were in the non-proliferative group (class II and V). In the proliferative group, the percentage of the patients with elevated basal creatinine levels, median daily proteinuria, anti-double-stranded DNA (dsDNA) positivity, low C3 and C4 levels, the presence of active urinary sediment, and median renal SLE Disease Activity Index (SLEDAI) scores at the time of kidney biopsy were significantly higher than the non-proliferative group. Renal response status during the 2-year follow-up after induction therapy was available for 99 patients. During this time, 70 (70.7%) patients had achieved CRR and time-to-CRR was similar between the proliferative and non-proliferative groups (p = 0.64, log-rank test). The Cox proportional hazards model showed that achievement of CRR was associated with female gender [HR: 2.15 (1.19-3.89 95% CI), p = 0.011], newly diagnosed SLE with renal biopsy [HR: 2.15 (1.26-3.67 95% CI), p = 0.005], hypertension [HR: 0.40 (0.27-0.94 95% CI), p = 0.032], eGFR increase [HR: 1.01 (1.00-1.01 95% CI), p = 0.046], and the presence of active urinary sediment [HR: 0.46 (0.22-0.96 95% CI), p = 0.039].

CONCLUSIONS

Achieving CRR was similar in proliferative and non-proliferative LN patients, although certain laboratory parameters differed at the onset. Our results indicated the importance of kidney biopsy in the decision-making of treatment of SLE patients with renal involvement and that the defined factors associated with CRR achievement help to predict good renal response.

A nationwide analysis of renal and patient outcomes for adults with lupus nephritis in Japan

BACKGROUND

The prognosis of lupus nephritis (LN) has improved following the introduction of effective immunosuppressive therapy and progress in supportive care. This study examined recent renal and patient prognosis for adults with LN in Japan.

METHODS

We conducted a nationwide retrospective cohort study of LN patients who received a renal biopsy between 2007 and 2012 that were registered in the Japan Renal Biopsy Registry. Of 623 registered adults with LN from 25 institutions and their affiliated or community hospitals, 489 were eligible for this study.

RESULTS

The median age at renal biopsy was 39 years, and 82.2% of patients were female. Renal biopsies were performed in 348 patients with new-onset LN, 106 with relapse LN, and 35 with refractory LN. The distribution of ISN/RPS 2003 Classes was as follows: I 1.6%; II 5.3%; III (± V) 27.0%; IV (± V) 47.0%; V 18.4%; VI 0.6%. During the median observation period of 63.8 months, 36 patients (7.3%) reached a doubling of serum creatinine or end-stage kidney disease (ESKD), and 28 patients (5.7%) died. The 5 year renal and patient survival rates were 93.9% and 94.7%, respectively. Multivariate analysis revealed body mass index (BMI) and estimated glomerular filtration rate (eGFR) were independent risk factors for a doubling of serum creatinine in ESKD. Age and eGFR were independent risk factors for death.

CONCLUSION

Recent prognosis for adults with LN are relatively good in Japan. Risk factors for impaired renal function are BMI and eGFR at renal biopsy, while age and eGFR are risk factors for death.

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.