Clinical and laboratory characteristics of early-onset and delayed-onset lupus nephritis patients: A single-center retrospective study

BACKGROUND

Lupus nephritis (LN) manifests systemic lupus erythematosus (SLE) and is characterized by various clinical and laboratory features. This study aimed to comprehensively evaluate the characteristics of LN patients according to the time of LN diagnosis: early-onset (LN diagnosed within one year from SLE diagnosis) vs. delayed-onset (LN diagnosed more than one year after SLE diagnosis).

METHODS

We conducted a retrospective analysis of medical records from all SLE patients treated at the University Hospital in Kraków, Poland, from 2012 to 2022. We collected data on demographic, clinical, and laboratory characteristics, including histological findings, treatment modalities, and disease outcomes. Statistical analyses were performed to identify factors impacting LN development and prognosis.

RESULTS

Among 331 LN patients, early-onset was diagnosed in 207 (62.54%) and delayed-onset was documented in 122 cases (36.86%). In 2 (0.6%) LN cases, the time of first kidney manifestation in the SLE course was unknown. Delayed-onset LN had a higher female-to-male ratio and younger age at SLE diagnosis. This group was associated with more severe clinical manifestations. In turn, studied subgroups did not differ in internist comorbidities, kidney histopathology, and family history regarding autoimmune diseases. Delayed-onset LN exhibited a higher frequency of anti-dsDNA, anti-Smith, anti-Ro, anti-RNP, and anti-cardiolipin IgG autoantibodies. During a 14-year follow-up period, 16 patients died. Mortality rate and causes of death were comparable in both analyzed subgroups.

CONCLUSIONS

More severe clinical manifestations in delayed-onset LN prompt strict monitoring of non-LN SLE patients to diagnose and treat kidney involvement early. Also, recognizing the higher frequency of autoantibodies such as anti-dsDNA or anti-Smith in delayed-onset LN underscores the potential value of autoantibody profiling as a diagnostic and prognostic tool.

Polygenic Risk Score Predicts Earlier-Onset Adult Systemic Lupus Erythematosus and First-Year Renal Diseases in a Taiwanese Cohort

OBJECTIVES

This study aimed to develop a predictive model using polygenic risk score (PRS) to forecast renal outcomes for adult systemic lupus erythematosus (SLE) in a Taiwanese population.

METHODS

Patients with SLE (n=2782) and matched non-SLE controls (n=11 128) were genotyped using Genome-Wide TWB 2.0 single-nucleotide polymorphism (SNP) array. PRS models (C+T, LDpred2, Lassosum, PRSice-2, PRS-continuous shrinkage (CS)) were constructed for predicting SLE susceptibility. Logistic regression was assessed for C+T-based PRS association with renal involvement in patients with SLE.

RESULTS

In the training set, C+T-based SLE-PRS, only incorporating 27 SNPs, outperformed other models with area under the curve (AUC) values of 0.629, surpassing Lassosum (AUC=0.621), PRSice-2 (AUC=0.615), LDpred2 (AUC=0.609) and PRS-CS (AUC=0.602). Additionally, C+T-based SLE-PRS demonstrated consistent predictive capacity in the testing set (AUC=0.620). Individuals in the highest quartile exhibited earlier SLE onset (39.06 vs 44.22 years, p<0.01), higher Systemic Lupus Erythematosus Disease Activity Index scores (3.00 vs 2.37, p=0.04), elevated risks of renal involvement within the first year of SLE diagnosis, including WHO class III-IV lupus nephritis (OR 2.36, 95% CI 1.47 to 3.80, p<0.01), estimated glomerular filtration rate <60 mL/min/1.73m2 (OR 1.49, 95% CI 1.18 to 1.89, p<0.01) and urine protein-to-creatinine ratio >150 mg/day (OR 2.07, 95% CI 1.49 to 2.89, p<0.01), along with increased seropositivity risks, compared with those in the lowest quartile. Furthermore, among patients with SLE with onset before 50 years, the highest PRS quartile was significantly associated with more serious renal diseases within the first year of SLE diagnosis.

CONCLUSIONS

PRS of SLE is associated with earlier onset, renal involvement within the first year of SLE diagnosis and seropositivity in Taiwanese patients. Integrating PRS with clinical decision-making may enhance lupus nephritis screening and early treatment to improve renal outcomes in patients with SLE.

Renal relapse in children and adolescents with childhood-onset lupus nephritis: a 20-year study

OBJECTIVES

There is little data on renal relapse in childhood-onset LN (cLN). We investigate the incidence, predictive factors and outcomes related to renal relapse.

METHODS

We conducted a retrospective cohort study of all cLN diagnosed at ≤18 years between 2001-2021 to investigate the incidence and outcomes related to renal relapse.

RESULTS

Ninety-five Chinese cLN patients (91% proliferative LN) were included. Induction immunosuppression was prednisolone and CYC [n = 36 (38%)] or MMF [n = 33 (35%)]. Maintenance immunosuppression was prednisolone and MMF [n = 53 (54%)] or AZA [n = 29 (31%)]. The rates of complete remission/partial remission (CR/PR) at 12 months were 78.9%/7.4%. Seventy renal relapses occurred in 39 patients over a follow-up of 10.2 years (s.d. 5.9) (0.07 episode/patient-year). Relapse-free survival was 94.7, 86.0, 80.1, 71.2, 68.3, 50.3 and 44.5% at 1, 2, 3, 4, 5, 10 and 20 years, respectively. Multivariate analysis showed that LN diagnosis <13.1 years [adjusted hazard ratio (HRadj) 2.59 995% CI 1.27, 5.29), P = 0.01], AZA maintenance [HRadj 2.20 (95% CI 1.01, 4.79), P = 0.05], PR [HRadj 3.9 (95% CI 1.03, 9.19), P = 0.01] and non-remission [HRadj 3.08 (95% CI 1.35, 11.3), P = 0.04] at 12 months were predictive of renal relapse. Renal relapse was significantly associated with advanced chronic kidney disease (stages 3-5) and end-stage kidney disease (17.9% vs 1.8%, P < 0.01). Furthermore, patients with renal relapse showed an increased incidence of infections (30.8% vs 10.7%, P = 0.02), osteopenia (38.5% vs 17.9%, P = 0.04) and hypertension (30.8% vs 7.1%, P < 0.01).

CONCLUSION

Renal relapse is common among cLN, especially among young patients, and is associated with an increased incidence of morbidity and mortality. Attaining CR and the use of MMF appear to decrease the incidence of renal relapse.

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.

Prevalence and outcomes of end-stage kidney disease in patients with systemic lupus erythematous: a population-based study

This study aims to examine the prevalence and outcomes of end-stage kidney disease (ESKD) among systemic lupus erythematosus (SLE) patients. SLE patients identified from the national administrative datasets were linked to the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) to identify the ESKD cases. Period prevalence of ESKD among SLE patients was calculated. The risk of developing ESKD by ethnicity was explored with Cox Proportional Hazards model. The adjusted hazard ratio (HR) of all-cause mortality for Māori, Pacific, Asian compared to European/others was estimated. Of the 2837 SLE patients, 210 (7.4%) developed ESKD. The average period prevalence of ESKD among SLE patients was 5.7%. Men had twice the prevalence rate of ESKD than women (10.0% vs 5.2%). Māori and Pacific had higher prevalence rate than Asian and European/others (9.4%, 9.8% vs 4.4% and 3.8%). The adjusted HR of developing ESKD for men compared to women was 3.37 (95% CI 1.62-7.02). The adjusted HR of developing ESKD for Māori and Pacific compared to European/others was 4.63 (95% CI 1.61-13.29) and 4.66 (95% CI 1.67-13.00), respectively. Compared to European/others, Māori had an HR of 2.17 (95% CI 1.18-4.00) for all-cause mortality. SLE patients had a high prevalence rate of ESKD. Men, Māori, and Pacific patients with SLE were more likely to develop ESKD. Māori patients with ESKD had poorer survival than other patients. Interventions are needed to reduce the risk of ESKD and to improve the survival of ESKD patients for the disadvantaged groups.

Predictors of renal relapse in Koreans with lupus nephritis after achieving complete response: a 35-years of experience at a single center

BACKGROUND/AIMS

Renal relapse has known to be a poor prognostic factor in patients with lupus nephritis (LN), but there were few studies that identified the risk factors of renal relapse in real world. We conducted this study based on 35-years of experience at a single center to find out predictors of renal relapse in Korean patients with LN after achieving complete response (CR).

METHODS

We retrospectively analyzed the clinical, laboratory, pathologic and therapeutic parameters in 296 patients of LN who reached CR. The cumulative risk and the independent risk factors for renal relapse were examined by Kaplan-Meier methods and Cox proportional hazards regression analyses, respectively.

RESULTS

The median follow-up period from CR was 123 months. Renal relapse had occurred in 157 patients. Renal relapse occurred in 38.2%, 57.6% and 67.9% of patients within 5-, 10-, and 20-year, respectively. The age at diagnosis of SLE and LN were significantly younger, and the proportions of severe proteinuria and serum hypoalbuminemia were higher in patients with renal relapse. Interestingly, the proportion of receiving cytotoxic maintenance treatment was higher in patients with renal relapse. In Cox proportional hazards regression analyses, only young-age onset of LN (by 10 years, HR = 0.779, p = 0.007) was identified to independent predictor of renal relapse.

CONCLUSION

Young-age onset of LN was only independent predictor and the patients with severe proteinuria and serum hypoalbuminemia also tended to relapse more, despite of sufficient maintenance treatment. Studies on more effective maintenance treatment regimens and duration are needed to reduce renal relapse.

Managing Lupus Nephritis in Children and Adolescents

Lupus nephritis is an important manifestation of systemic lupus erythematosus, which leads to chronic kidney disease, kidney failure, and can result in mortality. About 35%-60% of children with systemic lupus erythematosus develop kidney involvement. Over the past few decades, the outcome of patients with lupus nephritis has improved significantly with advances in immunosuppressive therapies and clinical management. Nonetheless, there is a paucity of high-level evidence to guide the management of childhood-onset lupus nephritis, because of the relatively small number of patients at each centre and also because children and adolescents are often excluded from clinical trials. Children and adults differ in more ways than just size, and there are remarkable differences between childhood- and adult-onset lupus nephritis in terms of disease severity, treatment efficacy, tolerance to medications and most importantly, psychosocial perspective. In this article, we review the 'art and science' of managing childhood-onset lupus nephritis, which has evolved in recent years, and highlight special considerations in this specific patient population.

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.

Proximity extension assay proteomics and renal single cell transcriptomics uncover novel urinary biomarkers for active lupus nephritis

OBJECTIVE

To identify urinary biomarkers that can distinguish active renal involvement in Lupus Nephritis (LN), a severe manifestation of systemic lupus erythematosus (SLE).

METHODS

Urine from 117 subjects, comprised of inactive SLE, active non-renal lupus, active LN, and healthy controls, were subjected to Proximity Extension Assay (PEA) based comprehensive proteomics followed by ELISA validation in an independent, ethnically diverse cohort. Proteomic data is also cross-referenced to renal transcriptomic data to elucidate cellular origins of biomarkers.

RESULTS

Systems biology analyses revealed progressive activation of cytokine signaling, chemokine activity and coagulation pathways, with worsening renal disease. In addition to validating 30 previously reported biomarkers, this study uncovers several novel candidates. Following ELISA validation in an independent cohort of different ethnicity, the six most discriminatory biomarkers for active LN were urinary ICAM-2, FABP4, FASLG, IGFBP-2, SELE and TNFSF13B/BAFF, with ROC AUC ≥80%, with most correlating strongly with clinical disease activity. Transcriptomic analyses of LN kidneys mapped the likely origin of these proteins to intra-renal myeloid cells (CXCL16, IL-1RT2, TNFSF13B/BAFF), T/NK cells (FASLG), leukocytes (ICAM2) and endothelial cells (SELE).

CONCLUSION

In addition to confirming the diagnostic potential of urine ALCAM, CD163, MCP1, SELL, ICAM1, VCAM1, NGAL and TWEAK for active LN, this study adds urine ICAM-2, FABP4, FASLG, IGFBP-2, SELE, and TNFSF13B/BAFF as additional markers that warrant systematic validation in larger cross-sectional and longitudinal cohorts.

Renal and survival benefits of seventeen prescribed Chinese herbal medicines against oxidative-inflammatory stress in systemic lupus erythematosus patients with chronic kidney disease: a real-world longitudinal study

Background: Systemic lupus erythematosus (SLE) significantly links to LN, a type of CKD with high mortality despite modern Western treatments. About 70% of SLE patients develop LN, and 30% advance to end-stage renal disease (ESRD). Concerns about glucocorticoid side effects and LN worsening due to oxidative stress prompt alternative treatment searches. In Taiwan, over 85% of SLE patients opt for complementary methods, especially Chinese herbal medicine (CHM). We pinpointed seventeen CHMs for SLE (PRCHMSLE) with antioxidative and anti-inflammatory properties from national health insurance data (2000-2017). Our primary aim was to assess their impact on renal and survival outcomes in SLE patients progressing to CKD (SLE-CKD), with a secondary focus on the risks of hospitalization and hyperkalemia. Methods: We established a propensity-matched cohort of 1,188 patients with SLE-CKD, comprising 594 PRCHMSLE users and 594 nonusers. We employed Cox proportional hazards models and restricted mean survival time (RMST) analyses to assess the renal and survival outcomes of PRCHMSLE users. Moreover, we performed pooling and network analyses, specifically focusing on the renal effects linked to PRCHMSLE. Results: PRCHMSLE use was associated with decreased adjusted hazard ratios for ESRD (0.45; 95% confidence interval, 0.25-0.79, p = 0.006), all-cause mortality (0.56; 0.43-0.75, p < 0.0001), non-cardiovascular mortality (0.56; 0.42-0.75, p < 0.0001), and hospitalization (0.72; 0.52-0.96, p = 0.009). Hyperkalemia risk did not increase. Significant differences in RMST were observed: 0.57 years (95% confidence interval, 0.19-0.95, p = 0.004) for ESRD, 1.22 years (0.63-1.82, p < 0.0001) for all-cause mortality, and 1.21 years (0.62-1.80, p < 0.0001) for non-cardiovascular mortality, favoring PRCHMSLE use. Notably renoprotective PRCHMSLE included Gan-Lu-Ying, Anemarrhena asphodeloides Bunge [Asparagaceae; Rhizoma Anemarrhenae] (Zhi-Mu), Rehmannia glutinosa (Gaertn.) DC. [Orobanchaceae; Radix Rehmanniae] (Sheng-Di-Huang), Jia-Wei-Xiao-Yao-San, and Paeonia suffruticosa Andr. [Paeoniaceae; Cortex Moutan] (Mu-Dan-Pi). Network analysis highlighted primary treatment strategies with central components like Liu-Wei-Di-Huang-Wan, Paeonia suffruticosa Andr. [Paeoniaceae; Cortex Moutan] (Mu-Dan-Pi), Anemarrhena asphodeloides Bunge [Asparagaceae; Rhizoma Anemarrhenae] (Zhi-Mu), Rehmannia glutinosa (Gaertn.) DC. [Orobanchaceae; Radix Rehmanniae] (Sheng-Di-Huang), and Zhi-Bai-Di-Huang-Wan. Conclusion: This work underscores the pronounced renal and survival benefits associated with the seventeen PRCHMSLE in the treatment of SLE-CKD, concurrently mitigating the risks of hospitalization and hyperkalemia. This highlights their potential as alternative treatment options for individuals with this condition.

Response to belimumab among patients with refractory lupus nephritis: a real-world observational retrospective multicenter study

OBJECTIVES

Belimumab is a biological agent approved for the treatment of active lupus nephritis (LN), but its efficacy on refractory lupus nephritis (LN) is unknown. This study aims to evaluate the efficacy and safety of belimumab in Chinese patients with refractory LN.

METHODS

This multicenter, observational, and retrospective study enrolled patients with refractory LN who failed induction therapy with steroids, cyclophosphamide, mycophenolate, and calcineurin inhibitors and received 24-week belimumab treatment before data analysis. Treatment outcomes include the overall clinical response (physician judgment, disease activity, organ damage) and renal response (complete renal response, partial renal response, no renal response). Laboratory indices and adverse events were recorded as well.

RESULTS

Of the 45 patients enrolled in the study, 6 (13.3%) achieved complete renal response, 19 (42.2%) achieved partial renal response, and the overall renal response rate was 55.6%. Median rSLEDAI decreased from 12 (IQR 8-12) at baseline to 8 (IQR 4-8) (p < 0.0001), 4 (IQR 4-8) (p < 0.0001) at 12 and 24 weeks. Mean urinary protein decreased more than 50% from 3.2 g/24 h at baseline to 1.0 g/24 h at 24 weeks (p < 0.0001). The conditions of hypoalbuminemia and hypocomplementemia had also gradually improved. The levels of autoantibodies showed a significant downward trend. Additionally, 9 (20.0%) patients successfully reduced the dosage of prednisone to a safe range, and 3 of them achieved their treatment goal of prednisone cessation. The mean prednisone dosage decreased from 32.7 mg/day at baseline to 18.6 mg/day (p < 0.0001), 13.3 mg/day (p < 0.0001) at 12 and 24 weeks. There were 3 adverse events reported, including 2 cases of infection, and 1 case of allergy. No serious events occurred during the follow-up.

CONCLUSIONS

Belimumab is effective and safe when used in clinical practice, which can be considered as an add-on therapy for refractory LN. Key Points • A multicenter observational study in the real clinical settings of China. • First revealed the efficacy and safety of belimumab in Chinese patients with refractory LN.

Chronic kidney disease: the missing concept in the 2019 EULAR/ERA-EDTA recommendations for lupus nephritis

Chronic kidney disease (CKD) is diagnosed when glomerular filtration rate (GFR) falls below 60 ml/min/1.73 m2 or urinary albumin:creatinine ratio (UACR) reaches ≥30 mg/g, as these two thresholds indicate a higher risk of adverse health outcomes, including cardiovascular mortality. CKD is classified as mild, moderate or severe, based on GFR and UACR values, and the latter two classifications convey a high or very high cardiovascular risk, respectively. Additionally, CKD can be diagnosed based on abnormalities detected by histology or imaging. Lupus nephritis (LN) is a cause of CKD. Despite the high cardiovascular mortality of patients with LN, neither albuminuria nor CKD are discussed in the 2019 European League Against Rheumatism (EULAR)/European Renal Association-European Dialysis and Transplant Association recommendations for the management of LN or the more recent 2022 EULAR recommendations for cardiovascular risk management in rheumatic and musculoskeletal diseases. Indeed, the proteinuria target values discussed in the recommendations may be present in patients with severe CKD and a very high cardiovascular risk who may benefit from guidance detailed in the 2021 European Society of Cardiology guidelines on cardiovascular disease prevention in clinical practice. We propose that the recommendations should move from a conceptual framework of LN as an entity separate from CKD to a framework in which LN is considered a cause of CKD and evidence generated from large CKD trials applies unless demonstrated otherwise.

Canadian patient experiences of lupus nephritis: a qualitative analysis

OBJECTIVE

Lupus nephritis (LN) is one of the most severe manifestations of SLE; however, we know little about the lived experience of LN. This research investigates patient experiences and perspectives of (1) LN diagnosis; (2) living with LN; and (3) LN healthcare and treatment.

METHODS

Patients aged ≥18 years with biopsy-proven pure or mixed International Society of Nephrology/Renal Pathology Society class III, IV or V LN were purposefully recruited from a Canadian lupus cohort to participate in semistructured in-depth interviews.

RESULTS

Thirty patients with LN completed the interviews. The mean (SD) age was 42.1 (16.4) years, and 86.7% were female. Participants described challenges seeking, receiving and adjusting to a LN diagnosis, and some reported that their diagnosis process took weeks to years. While 16 participants were provided resources by healthcare providers to help them through the process of diagnosis, the need for accessible LN-specific information at diagnosis was highlighted (n=18). Participants also described the unpredictability of living with LN, particularly related to impacts on physical and mental health, relationships, leisure activities, employment and education, and family planning. While most (n=26) participants reported a positive impression of their care, the side effects of LN medications and the need to increase patient and societal awareness/understanding of LN were highlighted in the context of healthcare and treatment.

CONCLUSIONS

The unpredictability of living with LN, the heavy treatment burden and a lack of patient/societal awareness substantially affect the lived experience of LN. These findings will inform the development of LN-specific patient resources to increase understanding of LN and improve well-being for patients.

Identification of driver genes in lupus nephritis based on comprehensive bioinformatics and machine learning

Background

Lupus nephritis (LN) is a common and severe glomerulonephritis that often occurs as an organ manifestation of systemic lupus erythematosus (SLE). However, the complex pathological mechanisms associated with LN have hindered the progress of targeted therapies.

Methods

We analyzed glomerular tissues from 133 patients with LN and 51 normal controls using data obtained from the GEO database. Differentially expressed genes (DEGs) were identified and subjected to enrichment analysis. Weighted gene co-expression network analysis (WGCNA) was utilized to identify key gene modules. The least absolute shrinkage and selection operator (LASSO) and random forest were used to identify hub genes. We also analyzed immune cell infiltration using CIBERSORT. Additionally, we investigated the relationships between hub genes and clinicopathological features, as well as examined the distribution and expression of hub genes in the kidney.

Results

A total of 270 DEGs were identified in LN. Using weighted gene co-expression network analysis (WGCNA), we clustered these DEGs into 14 modules. Among them, the turquoise module displayed a significant correlation with LN (cor=0.88, p<0.0001). Machine learning techniques identified four hub genes, namely CD53 (AUC=0.995), TGFBI (AUC=0.997), MS4A6A (AUC=0.994), and HERC6 (AUC=0.999), which are involved in inflammation response and immune activation. CIBERSORT analysis suggested that these hub genes may contribute to immune cell infiltration. Furthermore, these hub genes exhibited strong correlations with the classification, renal function, and proteinuria of LN. Interestingly, the highest hub gene expression score was observed in macrophages.

Conclusion

CD53, TGFBI, MS4A6A, and HERC6 have emerged as promising candidate driver genes for LN. These hub genes hold the potential to offer valuable insights into the molecular diagnosis and treatment of LN.

Long-term outcomes with rituximab as add-on therapy in severe childhood-onset lupus nephritis

BACKGROUND

Long-term data pertaining to rituximab as add-on therapy in childhood-onset lupus nephritis (cLN) is scarce.

METHODS

A retrospective cohort study was conducted on all patients with proliferative cLN, diagnosed ≤ 18 years and between 2005 and 2021, who received rituximab for LN episodes that were life/organ threatening and/or treatment resistant to standard immunosuppression.

RESULTS

Fourteen patients with cLN (female, n = 10) were included, with median follow-up period of 6.9 years. LN episodes (class III, n = 1; class IV, n = 11; class IV + V, n = 2) requiring rituximab occurred at 15.6 years (IQR 12.8-17.3), urine protein:creatinine ratio was 8.2 mg/mg (IQR 3.4-10.1) and eGFR was 28 mL/min/1.73 m2 (IQR 24-69) prior to rituximab treatment. Ten and four patients received rituximab at 1500 mg/m2 and 750 mg/m2, which were given at 46.5 days (IQR 19-69) after commencement of standard therapies. Treatment with rituximab resulted in improvements in proteinuria (ps < 0.001), eGFR (ps < 0.01) and serological parameters, including haemoglobin levels, complement 3 levels and anti-dsDNA antibodies, compared with baseline. Rates of complete/partial remission at 6-, 12- and 24-month post-rituximab were 28.6/42.8%, 64.2/21.4% and 69.2/15.3%. All three patients who required acute kidney replacement therapy became dialysis-free after rituximab. Relapse rate following rituximab was 0.11 episodes/patient-year. There was no lethal complication or severe infusion reaction. Hypogammaglobulinaemia was the most frequent complication (45%) but was mostly asymptomatic. Neutropenia and infections were observed in 20% and 25% of treatments. Upon last follow-up, three (21%) and two (14%) patients developed chronic kidney disease (stage 2, n = 2; stage 4; n = 1) and kidney failure, respectively.

CONCLUSION

Add-on rituximab is an effective and safe rescue therapy for cLN patients with life-/organ-threatening manifestations or treatment-resistance. A higher resolution version of the Graphical abstract is available as Supplementary information.

Nrf2/HO-1 as a therapeutic target in renal fibrosis

Chronic kidney disease (CKD) is one of the most prevalent chronic diseases and affects between 10 and 14 % of the world's population. The World Health Organization estimates that by 2040, the disease will be fifth in prevalence. End-stage CKD is characterized by renal fibrosis, which can eventually lead to kidney failure and death. Renal fibrosis develops due to multiple injuries and involves oxidative stress and inflammation. In the human body, nuclear factor erythroid 2-related factor 2 (Nrf2) plays an important role in the expression of antioxidant, anti-inflammatory, and cytoprotective genes, which prevents oxidative stress and inflammation damage. Heme oxygenase (HO-1) is an inducible homolog influenced by heme products and after exposure to cellular stress inducers such as oxidants, inflammatory chemokines/cytokines, and tissue damage as an outcome or downstream of Nrf2 activation. HO-1 is known for its antioxidative properties, which play an important role in regulating oxidative stress. In renal diseases-induced tissue fibrosis and xenobiotics-induced renal fibrosis, Nrf2/HO-1 has been targeted with promising results. This review summarizes these studies and highlights the interesting bioactive compounds that may assist in attenuating renal fibrosis mediated by HO-1 activation. In conclusion, Nrf2/HO-1 signal activation could have a renoprotective effect strategy against CKD caused by oxidative stress, inflammation, and consequent renal fibrosis.

Efficacy and safety of multi-target therapy in children with lupus nephritis

BACKGROUND

To analyze the efficacy and safety of multi-target therapy in children with lupus nephritis (LN).

METHODS

In our retrospective study from January 2009 to December 2021, the multi-target therapy of glucocorticoids, MMF and tacrolimus was adopted as induction therapy or re-induction therapy for 36 LN children who had combined proliferative and membranous LN or for who were ineffective to combination therapy of glucocorticoids with IV-CYC or MMF for at least 6 months. The clinical and pathological data were collected and analyzed.

RESULTS

The levels of 24-h urinary protein, anti-dsDNA antibody and SLE disease activity index were decreased, while the levels of albumin and complement 3 were increased after multi-target therapy. More than 90% of LN children achieved partial or complete remission within 6 months. In terms of adverse effects, there was no significant difference between the level of eGFR before and after multi-target therapy. During the follow-up period, four children had infection, two children had hyperuricemia, and one child had liver dysfunction. All of them improved after symptomatic therapy.

CONCLUSIONS

Multi-target therapy could be an effective treatment option with minimal adverse effects for LN children who are refractory to initial first-line induction therapies or had combined proliferative and membranous LN.

IMPACT

The multi-target therapy of glucocorticoids, mycophenolate mofetil and tacrolimus was adopted in 36 children with lupus nephritis. Multi-target therapy could be an effective treatment option for lupus nephritis children who are refractory to initial first-line induction therapies or had combined proliferative and membranous lupus nephritis. Adverse effects of multi-target therapy were infrequent and minimal that can be improved by symptomatic therapy.

Clinicopathological characteristics and outcomes of lupus nephritis patients with scanty immune depositions in kidney biopsies

BACKGROUND

The clinicopathological features, outcomes, and pathogenesis of lupus nephritis with scanty immune deposits in the kidney biopsy remain unclear.

METHODS

Four hundred ninety-eight biopsy-proven lupus nephritis patients were included, and clinical and pathological data were collected. The primary endpoint was mortality, while the secondary endpoint was doubling baseline serum creatinine or end-stage renal disease. Associations between scanty immune deposits lupus nephritis and adverse outcomes were analyzed by Cox regression models.

RESULTS

Among 498 lupus nephritis patients, 81 were diagnosed with scanty immune deposits. Patients with scanty immune deposits had significantly higher serum albumin and serum complement C4 than those with immune complex deposits. The proportion of anti-neutrophil cytoplasmic antibodies was similar between the two groups. In addition, patients with scanty immune deposits showed less proliferative features at kidney biopsy and lower activity index score, accompanied by milder mesangial cell and matrix hyperplasia, endothelial cell hyperplasia, nuclear fragmentation, and glomerular leukocyte infiltration. Patients in this group also had a milder degree of foot process fusion. Overall, renal survival and patient survival showed no significant difference between the two groups. 24-h proteinuria and chronicity index were significant risk factors for renal survival, and 24-h proteinuria and positive anti-neutrophil cytoplasmic antibodies were risk factors for patient survival in scanty immune deposits lupus nephritis patients.

CONCLUSIONS

Compared with other lupus nephritis patients, scanty immune deposits lupus nephritis patients had significantly lower activity features on kidney biopsy, but have similar outcomes. Positive anti-neutrophil cytoplasmic antibodies may be a risk factor for patient survival in scanty immune deposits lupus nephritis patients.

Endothelial cell activation and glycocalyx shedding - potential as biomarkers in patients with lupus nephritis

Lupus nephritis (LN) is a common and severe manifestation of systemic lupus erythematosus and an important cause of acute and chronic kidney injury. Early diagnosis of LN and preventing relapses are key to preserving renal reserve. However, due to the complexity and heterogeneity of the disease, clinical management remains challenging. Kidney biopsy remains the gold standard for confirming the diagnosis of LN and subsequent assessment of kidney histopathology, but it is invasive and cannot be repeated frequently. Current clinical indicators of kidney function such as proteinuria and serum creatinine level are non-specific and do not accurately reflect histopathological changes, while anti-dsDNA antibody and C3 levels reflect immunological status but not kidney injury. Identification of novel and specific biomarkers for LN is prerequisite to improve management. Renal function deterioration is associated with changes in the endothelial glycocalyx, a delicate gel-like layer located at the interface between the endothelium and bloodstream. Inflammation induces endothelial cell activation and shedding of glycocalyx constituents into the circulation. This review discusses the potential role of soluble glycocalyx components as biomarkers of active LN, especially in patients in whom conventional serological and biochemical markers do not appear helpful.

Role of the transcription factor Fli-1 on the CXCL10/CXCR3 Axis

The transcription factor Fli-1, a member of the ETS family of transcription factors, is implicated in the pathogenesis of lupus disease. Reduced Fli-1 expression in lupus mice leads to decreased renal Cxcl10 mRNA levels and renal infiltrating CXCR3+ T cells that parallels reduced renal inflammatory cell infiltration and renal damage. Inflammatory chemokine CXCL10 is critical for attracting inflammatory cells expressing the chemokine receptor CXCR3. The CXCL10/CXCR3 axis plays a role in the pathogenesis of various inflammatory diseases including lupus. Our data here demonstrate that renal CXCL10 protein levels are significantly lower in Fli-1 heterozygous MRL/lpr mice compared to wild-type MRL/lpr mice. Knockdown of Fli-1 significantly reduced CXCL10 secretion in mouse and human endothelial cells, and human mesangial cells, upon LPS or TNFα stimulation. The Fli-1 inhibitor, Camptothecin, significantly reduced CXCL10 production in human monocyte cells upon interferon stimulation. Four putative Ets binding sites in the Cxcl10 promoter showed significant enrichment for FLI-1; however, FLI-1 did not directly drive transcription from the human or mouse promoters, suggesting FLI-1 may regulate CXCL10 expression indirectly. Our results also suggest that the DNA binding domain of FLI-1 is necessary for regulation of human hCXCR3 promotor activity in human T cells and interactions with co-activators. Together, these results support a role for FLI-1 in modulating the CXCL10-CXCR3 axis by directly or indirectly regulating the expression of both genes to impact lupus disease development. Signaling pathways or drugs that reduce FLI-1 expression may offer novel approaches to lupus treatment.

Research progress in functional magnetic resonance imaging assessment of lupus nephritis kidney injury

Lupus nephritis is one of the most common and severe complications of systemic lupus erythematosus and is also a major predictor of poor prognosis and mortality. Lupus nephritis has the characteristics of insidious onset, complex pathological types, rapid progression of organ damage, and easy recurrence. Currently, kidney damage in lupus nephritis is usually assessed based on urine analysis, renal biopsy, and glomerular filtration rates. However, they all have certain limitations, making it difficult to diagnose lupus nephritis early and assess its severity and progression. With the rapid development of functional magnetic resonance, multiple functional imaging techniques are expected to provide more useful information for the pathophysiological development, early diagnosis, progression, prognosis, and renal function evaluation of lupus nephritis. This article reviews the principle of multiple functional magnetic resonance imaging and the research status of evaluating renal function in lupus nephritis.

[Diagnostic and therapy of lupus nephritis - 2023]

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

Weaning Maintenance Therapy in Lupus Nephritis: For Whom, When, and How?

Lupus nephritis (LN) is one of the main determinants of the severity of systemic lupus erythematosus (SLE). LN flares can lead to organ damage with chronic kidney disease (CKD) or even end-stage kidney disease (ESKD) and impair patients' survival. The "treat-to-target" strategy, which aims at obtaining and maintaining remission or low disease activity of SLE to alleviate symptoms and prevent organ damage, also refers to the control of residual activity in the kidney. But damage in SLE can also come from treatments, and toxicities related to long-term use of treatments should be prevented. This may contribute to the frequent nonadherence in patients with SLE. The de-escalation or even weaning of treatments whenever possible, or "think-to-untreat" (T2U) strategy, is to be considered in patients with LN. This possibility of treatment weaning in LN was explored in retrospective cohorts, on the basis of long-term clinical remission. It was also proposed prospectively with a kidney-biopsy-based approach, combining clinical and pathologic remission to secure treatment weaning. The WIN-Lupus trial was the first randomized controlled trial comparing the continuation to the discontinuation of maintenance immunosuppressive therapy (IST) after 2 to 3 years in patients with LN in remission. It showed a higher risk of severe SLE flares in patients who discontinued treatment, but also a possibility of weaning without flare in some patients, who need to be better identified. We propose here a narrative review of the available literature on the weaning of treatment in LN and discuss how to secure a T2U strategy.

Disease modification achievement in patients with lupus nephritis in a real-life setting: mission impossible?

OBJECTIVE

A preliminary definition of disease modification (DM) in lupus nephritis (LN) was recently developed focusing on long-term remission and damage prevention, with minimal treatment-associated toxicity. We aimed to further specify aspects of DM criteria in LN, assess DM achievement in a real-world setting and examine potential DM predictors and long-term outcomes.

METHODS

We collected clinical/laboratory and histological inception cohort data from biopsy-proven LN patients (82% females) with ≥72 months follow-up at two joint academic centres. Specific criteria for 24-hour proteinuria, estimated glomerular filtration rate (eGFR), renal flares and glucocorticoids dose were set at three time frames (months 0-12, 13-60 and 72) to assess DM. In the first model, DM was achieved if patients fulfilled all four criteria at all three time frames (achievers). In the second model, the continued glucocorticoids reduction criterion was excluded. Logistic regression analyses were performed. Possible different trends in DM achievement between past and recent decades were also investigated.

RESULTS

DM was achieved by 60% of patients, increased to 70% when glucocorticoids excluded from DM criteria. 24-hour proteinuria at 9 months predicted DM achievement (OR 0.72, 95% CI 0.53 to 0.97, p=0.03), but none of baseline characteristics. Among patients with >72 month follow-up, non-achievers had worse renal outcomes (flares, >30% proteinuria increase, eGFR decline) than achievers at the end of follow-up (median 138 months). Patients diagnosed between 1992 and 2005 were found to have significantly lower percentages of DM achievement and met less often the glucocorticoids dose reduction criterion in all three time frames, compared with those diagnosed between 2006 and 2016 (p=0.006 and p<0.01, respectively).

CONCLUSIONS

DM was achieved by only 60% of LN patients in a real-life setting, partly due to lack of glucocorticoids dose target attainment, while DM failure was associated with worse long-term renal outcomes. This may imply limitations in the effectiveness or implementation of current LN treatments, supporting the need for novel therapeutic strategies.

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.

Healthcare Resource Utilization and Associated Costs in Patients With Systemic Lupus Erythematosus Diagnosed With Lupus Nephritis

BACKGROUND

Lupus nephritis (LN) is among the most severe organ manifestations of systemic lupus erythematosus (SLE), affecting between 31% and 48% of patients, usually within five years of SLE diagnosis. SLE without LN is associated with a high economic burden on the healthcare system, and although data are limited, several studies have shown that SLE with LN could increase this burden.  Aim: We aimed to compare the economic burden of LN versus SLE without LN among patients managed in routine clinical practices in the USA and describe the clinical course of these patients.

MATERIALS AND METHODS

This was a retrospective observational study of patients with commercial or Medicare Advantage health insurance. It included 2310 patients with LN and 2310 matched patients who had SLE without LN; each patient was followed for 12 months after diagnosis (the patient's index date). Outcome measures included healthcare resource utilization (HCRU), direct healthcare costs, and SLE clinical manifestations.  Results: In all healthcare settings, the mean (SD) use of all-cause healthcare resources was significantly higher in the LN versus SLE without LN cohort, including the mean number of ambulatory visits (53.9 (55.1) vs 33.0 (26.0)), emergency room visits (2.9 (7.9) vs 1.6 (3.3)), inpatient stays (0.9 (1.5) vs 0.3 (0.8)), and pharmacy fills (65.0 (48.3) vs 51.2 (42.6)) (all p<0.001). Total all-cause costs per patient in the LN cohort were also significantly higher compared with the SLE without LN cohort ($50,975 (86,281) vs $26,262 (52,720), p<0.001), including costs for inpatient stays and outpatient visits. Clinically, a significantly higher proportion of patients with LN experienced moderate or severe SLE flares compared with the SLE without LN cohort (p<0.001), which may explain the difference in HCRU and healthcare costs.

CONCLUSION

All-cause HCRU and costs were higher for patients with LN than for matched patients with SLE without LN, highlighting the economic burden associated with LN.

Incidence, Prevalence, and Mortality of Lupus Nephritis: A Population-Based Study Over Four Decades Using the Lupus Midwest Network

OBJECTIVE

There is a paucity of population-based studies investigating the epidemiology of lupus nephritis (LN) in the US and long-term secular trends of the disease and its outcomes. We aimed to examine the epidemiology of LN in a well-defined 8-county region in the US.

METHODS

Patients with incident LN between 1976 and 2018 in Olmsted County, Minnesota (1976-2009) and an 8-county region in southeast Minnesota (2010-2018) were identified. Age- and sex-specific incidence rates and point prevalence over 4 decades, adjusted to the projected 2000 US population, were determined. Standardized mortality ratios (SMRs), survival rates, and time to end-stage renal disease (ESRD) were estimated.

RESULTS

There were 72 patients with incident LN between 1976 and 2018, of whom 76% were female and 69% were non-Hispanic White. Mean ± SD age at diagnosis was 38.4 ± 16.24 years. Average annual LN incidence per 100,000 population between 1976 and 2018 was 1.0 (95% CI 0.8-1.3) and was highest in patients ages 30-39 years. Between the 1976-1989 and 2000-2018 time periods, overall incidence of LN increased from 0.7 to 1.3 per 100,000, but this was not statistically significant. Estimated LN prevalence increased from 16.8 per 100,000 in 1985 to 21.2 per 100,000 in 2015. Patients with LN had an SMR of 6.33 (95% CI 3.81-9.89), with no improvement in the mortality gap in the last 4 decades. At 10 years, survival was 70%, and 13% of LN patients had ESRD.

CONCLUSION

The incidence and prevalence of LN in this area increased in the last 4 decades. LN patients have poor outcomes, with high rates of ESRD and mortality rates 6 times that of the general population.

Risk factors for subsequent lupus nephritis in patients with juvenile-onset systemic lupus erythematosus: a retrospective cohort study

BACKGROUND

Lupus nephritis (LN) is a crucial organ involvement in systemic lupus erythematosus (SLE). Patients with LN have higher morbidity and mortality rates than those without. Among all patients with LN, 20-40% had delayed onset, but the data for patients with juvenile-onset SLE (jSLE), who have a higher percentage of LN than patients with adult-onset SLE (aSLE), were limited. This study aimed to determine the risk factors for subsequent LN in patients with jSLE.

METHODS

A retrospective cohort study was conducted between 2008 and 2018 in a single tertiary medical centre. Patients with diagnosed jSLE were reviewed. We investigated those without LN at diagnosis and whether they developed LN afterward. The primary outcome was the development of subsequent LN. Clinical manifestations at diagnosis, serial laboratory data, and treatments were reviewed during follow-up periods.

RESULTS

Among the 48 patients with jSLE without initial LN, 20 developed subsequent LN later (Group 1), whereas 28 remained free of LN (Group 2). There was no difference in the percentage of initial manifestations except for more discoid rashes in Group 2 patients. In the Cox regression model, elevated average anti-double-stranded DNA (dsDNA) antibody, low average serum complements, and high average erythrocyte sedimentation rate (ESR) levels during follow-up were predictors of subsequent LN. After adjusting for these factors in multivariable analyses, only high average anti-dsDNA antibody and high average ESR levels remained predictive of subsequent LN. For every 100 IU/ml increase in anti-dsDNA antibody, the risk for subsequent LN in jSLE increases by 1.29 times (hazard ratio = 1.29, 95% confidence interval 1.055-1.573).

CONCLUSION

Persistently high anti-dsDNA antibody and ESR levels during the follow-up period were risk factors for subsequent LN in patients with jSLE.

Pathogenesis of lupus nephritis: the contribution of immune and kidney resident cells

PURPOSE OF REVIEW

Lupus nephritis is associated with significant mortality and morbidity. We lack effective therapeutics and biomarkers mostly because of our limited understanding of its complex pathogenesis. We aim to present an overview of the recent advances in the field to gain a deeper understanding of the underlying cellular and molecular mechanisms involved in lupus nephritis pathogenesis.

RECENT FINDINGS

Recent studies have identified distinct roles for each resident kidney cell in the pathogenesis of lupus nephritis. Podocytes share many elements of innate and adaptive immune cells and they can present antigens and participate in the formation of crescents in coordination with parietal epithelial cells. Mesangial cells produce pro-inflammatory cytokines and secrete extracellular matrix contributing to glomerular fibrosis. Tubular epithelial cells modulate the milieu of the interstitium to promote T cell infiltration and formation of tertiary lymphoid organs. Modulation of specific genes in kidney resident cells can ward off the effectors of the autoimmune response including autoantibodies, cytokines and immune cells.

SUMMARY

The development of lupus nephritis is multifactorial involving genetic susceptibility, environmental triggers and systemic inflammation. However, the role of resident kidney cells in the development of lupus nephritis is becoming more defined and distinct. More recent studies point to the restoration of kidney resident cell function using cell targeted approaches to prevent and treat lupus nephritis.

Efficacy and Safety of Belimumab in Patients With Lupus Nephritis: Subgroup Analyses of a Phase 3 Randomized Trial in the East Asian Population

RATIONALE & OBJECTIVE

Belimumab improved kidney outcomes in patients with active lupus nephritis (LN) in BLISS-LN, leading to its approval in the United States and the European Union. As data on treatment of East Asian patients with LN are limited, we evaluated the efficacy and safety of belimumab in the BLISS-LN East Asian subgroup.

STUDY DESIGN

Prespecified subgroup analysis of BLISS-LN, a phase 3, placebo-controlled, randomized 104-week trial.

SETTING & PARTICIPANTS

Adults with biopsy-proven, active LN were randomized (1:1) to belimumab or placebo, plus standard therapy.

INTERVENTION

Patients were administered intravenous belimumab 10mg/kg, or placebo, plus standard therapy (oral glucocorticoids and either cyclophosphamide for induction followed by azathioprine for maintenance, or mycophenolate mofetil for both induction and maintenance). At the investigator's discretion, 1-3 intravenous pulses of methylprednisolone, 500-1,000mg each, could be administered during induction.

OUTCOMES

The primary end point was primary efficacy renal response (PERR; ie, urinary protein-creatinine ratio≤0.7g/g, estimated glomerular filtration rate no more than 20% below preflare value or≥60mL/min/1.73m², and no treatment failure) at week 104. Key secondary end points included complete renal response (CRR; urinary protein-creatinine ratio<0.5g/g, estimated glomerular filtration rate no more than 10% below preflare value or≥90mL/min/1.73m², and no treatment failure) at week 104; PERR at week 52; time to kidney-related event or death; and safety.

ANALYTICAL APPROACH

PERR and CRR were analyzed using a logistic regression model, and time to a kidney-related event or death was analyzed using a Cox proportional hazards regression model.

RESULTS

142 patients from mainland China, Hong Kong, South Korea, and Taiwan were included (belimumab, n=74; placebo, n=68). At week 104, more belimumab than placebo patients achieved PERR (53% vs 37%; OR, 1.76 [95% CI, 0.88-3.51]) and CRR (35% vs 25%; OR, 1.73 [95% CI, 0.80-3.74]). At week 52, more belimumab than placebo patients achieved PERR (62% vs 37%; OR, 2.74 [95% CI, 1.33-5.64]). Belimumab reduced the risk of a kidney-related event or death compared with placebo at any time (HR, 0.37 [95% CI, 0.15-0.91]). Safety was similar across treatment groups.

LIMITATIONS

Small sample size and lack of formal significance testing.

CONCLUSIONS

Safety and efficacy profiles were consistent with BLISS-LN overall population, supporting benefits of belimumab treatment in the East Asian subgroup with LN.

FUNDING

This study was funded by GSK (GSK study no. BEL114054).

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT01639339.

A Preliminary Predictive Model for Proliferative Lupus Nephritis in Juvenile Systemic Lupus Erythematosus

Proliferative lupus nephritis, which is diagnosed by renal biopsy, has significant impact on the treatment choices and long-term prognosis of juvenile SLE (jSLE). Renal biopsies are however not always possible or available, thus leading to an ongoing search for alternative biomarkers. This study aimed to develop a clinical predictive machine learning model using routine standard parameters as an alternative tool to evaluate the probability of proliferative lupus nephritis (ISN/RPS Class III or IV). Data were collected retrospectively from jSLE patients seen at Selayang Hospital from 2004 to 2021. A total of 22 variables including demographic, clinical and laboratory features were analyzed. A recursive feature elimination technique was used to identify factors to predict pediatric proliferative lupus nephritis. Various models were then used to build predictive machine learning models and assessed for sensitivity, specificity and accuracy. There were 194 jSLE patients (165 females), of which 111 had lupus nephritis (54 proliferative pattern). A combination of 11 variables consisting of gender, ethnicity, fever, nephrotic state, hypertension, urine red blood cells (RBC), C3, C4, duration of illness, serum albumin, and proteinuria demonstrated the highest accuracy of 79.4% in predicting proliferative lupus nephritis. A decision-tree model performed the best with an AROC of 69.9%, accuracy of 73.85%, sensitivity of 78.72% and specificity of 61.11%. A potential clinically useful predictive model using a combination of 11 non-invasive variables to collectively predict pediatric proliferative lupus nephritis in daily practice was developed.

Clinical and Economic Burden of Systemic Lupus Erythematosus in the Years Preceding End-Stage Kidney Disease Diagnosis: A Retrospective Observational Study

INTRODUCTION

This study aimed to describe the clinical burden, healthcare resource utilisation (HCRU) and healthcare costs for patients with systemic lupus erythematosus (SLE) in the 12-60 months preceding an end-stage kidney disease (ESKD) diagnosis in the USA.

METHODS

This retrospective observational study identified adult patients with SLE with newly diagnosed ESKD between 1 March 2012 and 31 December 2018 using administrative claims data. Clinical characteristics, mean all-cause HCRU (i.e. any HCRU visit and pharmacy fill) and total all-cause healthcare costs (comprising medical and pharmacy costs in 2019 US dollars) were assessed during the 12 months pre-ESKD diagnosis and yearly during the 5 years pre-ESKD diagnosis among patients with ≥ 5 years of continuous health plan enrolment.

RESULTS

Of the 1356 patients included, 51.2% had severe SLE, 71.2% had lupus nephritis (LN) and 20.6% underwent kidney biopsy during the 12 months pre-ESKD. The mean (standard deviation [SD]) number of HCRU visits during the 12 months pre-ESKD was 78.0 (64.1) per patient. The mean (SD) total healthcare costs per patient in the 12 months pre-ESKD diagnosis was $64,887 (106,822), driven by medical costs $51,764 (96,458). The proportions of patients with severe SLE, LN and those undergoing biopsy increased from year 5 to year 1 pre-ESKD diagnosis. The mean (SD) number of HCRU visits increased from year 5 (61.6 [54.0]) to year 1 (83.2 [62.1]) pre-ESKD. Mean (SD) total healthcare costs rose year on year from year 5 ($34,890 [74,346]) to year 1 ($73,236 [114,584]) pre-ESKD.

CONCLUSION

There were substantial clinical burden and healthcare costs among patients with SLE in the 12 months pre-ESKD diagnosis. The clinical burden and healthcare costs generally increased with each year approaching ESKD diagnosis. Early interventions for patients with SLE could prevent the development of ESKD, mitigating the burden of the disease.

Rituximab in the real-world treatment of lupus nephritis: A retrospective cohort study in Japan

OBJECTIVES

Although recommended in established international guidelines for lupus nephritis (LN), rituximab is not officially approved for LN treatment, making all such use off-label. The Japan College of Rheumatology (JCR) conducted a retrospective observational study on real-world efficacy and safety of rituximab treatment for LN in Japan.

METHODS

Clinical data were collected from 47 hospitals for LN patients treated with rituximab to retrospectively investigate dosing schedule, efficacy, and safety.

RESULTS

This retrospective analysis included 115 patients: 84 (73%) received 375 mg/m2 weekly up to four doses, and 31 (27%) received 1000 mg/body in one or two doses 2 weeks apart. Rituximab significantly improved findings for urinalysis, systemic lupus erythematosus serology, and systemic lupus erythematosus disease activity and was assessed as 'extremely effective' in 24.8% of patients and 'effective' in 60.2%. The renal response by the JCR-I criteria was 52.5% for overall response rate (ORR) (complete renal response rate 20.8% and partial renal response rate 31.7%) and that by the JCR-II criteria was 49.5% (21.8% and 27.7%, respectively). Corticosteroid dose was significantly reduced. Rituximab was well tolerated, with frequent but manageable adverse events of infusion reaction and infection.

CONCLUSIONS

Rituximab is effective for the treatment of Japanese patients with LN refractory to conventional therapy.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Predicting diagnostic gene expression profiles associated with immune infiltration in patients with lupus nephritis

Objective

To identify potential diagnostic markers of lupus nephritis (LN) based on bioinformatics and machine learning and to explore the significance of immune cell infiltration in this pathology.

Methods

Seven LN gene expression datasets were downloaded from the GEO database, and the larger sample size was used as the training group to obtain differential genes (DEGs) between LN and healthy controls, and to perform gene function, disease ontology (DO), and gene set enrichment analyses (GSEA). Two machine learning algorithms, least absolute shrinkage and selection operator (LASSO) and support vector machine-recursive feature elimination (SVM-RFE), were applied to identify candidate biomarkers. The diagnostic value of LN diagnostic gene biomarkers was further evaluated in the area under the ROC curve observed in the validation dataset. CIBERSORT was used to analyze 22 immune cell fractions from LN patients and to analyze their correlation with diagnostic markers.

Results

Thirty and twenty-one DEGs were screened in kidney tissue and peripheral blood, respectively. Both of which covered macrophages and interferons. The disease enrichment analysis of DEGs in kidney tissues showed that they were mainly involved in immune and renal diseases, and in peripheral blood it was mainly enriched in cardiovascular system, bone marrow, and oral cavity. The machine learning algorithm combined with external dataset validation revealed that C1QA(AUC = 0.741), C1QB(AUC = 0.758), MX1(AUC = 0.865), RORC(AUC = 0.911), CD177(AUC = 0.855), DEFA4(AUC= 0.843)and HERC5(AUC = 0.880) had high diagnostic value and could be used as diagnostic biomarkers of LN. Compared to controls, pathways such as cell adhesion molecule cam, and systemic lupus erythematosus were activated in kidney tissues; cell cycle, cytoplasmic DNA sensing pathways, NOD-like receptor signaling pathways, proteasome, and RIG-1-like receptors were activated in peripheral blood. Immune cell infiltration analysis showed that diagnostic markers in kidney tissue were associated with T cells CD8 and Dendritic cells resting, and in blood were associated with T cells CD4 memory resting, suggesting that CD4 T cells, CD8 T cells and dendritic cells are closely related to the development and progression of LN.

Conclusion

C1QA, C1QB, MX1, RORC, CD177, DEFA4 and HERC5 could be used as new candidate molecular markers for LN. It may provide new insights into the diagnosis and molecular treatment of LN in the future.

Prescribing Patterns of Hydroxychloroquine and Glucocorticoids Among Lupus Patients After New-Onset End-Stage Renal Disease

OBJECTIVE

Optimal strategies for managing lupus medications after end-stage renal disease (ESRD) have not been addressed. The objective was to identify the current US-wide prescribing patterns of hydroxychloroquine (HCQ) and oral glucocorticoids (GS) among systemic lupus erythematosus (SLE) patients with incident ESRD enrolled in the US Renal Data System (USRDS) registry.

METHODS

We identified incident ESRD patients age ≥18 years with SLE as a primary cause of ESRD between January 2006 and June 2013. Patients who were started on dialysis at ESRD onset and enrolled in Medicare Part D within 93 days as required by Medicare were included.

RESULTS

Among the 2,654 new-onset ESRD patients with Part D, the median duration of follow-up was 761 days (interquartile range [IQR] 374-1,375). At baseline, 1,076 patients (41%) were not receiving HCQ or GS, 220 (8%) were prescribed HCQ alone, 509 (19%) were prescribed both HCQ and GS, and 849 (32%) were prescribed GS alone. Of the 1,983 patients who either never received or discontinued HCQ after ESRD onset, 667 (34%) continued GS to the end of the follow-up period. The median GS dose was lower for patients taking HCQ (14 mg [IQR 9-21]) compared to patients who were never prescribed HCQ (15 mg [IQR 9-27]) or patients who discontinued HCQ after ESRD (17 mg [IQR 10-27]; P = 0.001).

CONCLUSION

Approximately one-third of patients with lupus nephritis and new-onset ESRD received GS monotherapy at high doses. As GS-related complications contribute to hospitalizations and deaths in SLE ESRD, changing these prescribing practices may improve morbidity and mortality outcomes.

Lupus, DNA Methylation, and Air Pollution: A Malicious Triad

The pathogenesis of systemic lupus erythematosus (SLE) remains elusive to this day; however, genetic, epigenetic, and environmental factors have been implicated to be involved in disease pathogenesis. Recently, it was demonstrated that in systemic lupus erythematosus (SLE) patients, interferon-regulated genes are hypomethylated in naïve CD4⁺ T cells, CD19⁺ B lymphocytes, and CD14⁺ monocytes. This suggests that interferon-regulated genes may have been epigenetically poised in SLE patients for rapid expression upon stimulation by different environmental factors. Additionally, environmental studies have identified DNA (hypo)methylation changes as a potential mechanism of environmentally induced health effects in utero, during childhood and in adults. Finally, epidemiologic studies have firmly established air pollution as a crucial SLE risk factor, as studies showed an association between fine particulate matter (PM_2.5) and traditional SLE biomarkers related to disease flare, hospital admissions, and an increased SLEDAI score. In this review, the relationship between aberrant epigenetic regulation, the environment, and the development of SLE will be discussed.

The influence of repeated flares in response to therapy and prognosis in lupus nephritis

Background

Repeated renal flares in lupus nephritis (LN) have been associated with worse long-term kidney function. This study aimed to assess the impact of repeated LN flares in response to therapy, kidney and patient prognosis.

Methods

All patients from a biopsy-proven LN cohort between 2008 and 2018 were segregated into three groups according to the number of LN flares when they entered our cohort: first LN flare, second LN flare or third LN flare. The following outcomes were evaluated by unadjusted and adjusted time-to-event analyses: complete and partial response, disease relapses, progression to decline of 30% of the estimated glomerular filtration rate (eGFR), doubling of serum creatinine, end-stage kidney disease and patient survival.

Results

A total of 441 patients were included: 257 (58%) in their first LN flare, 102 (23%) in their second LN flare and 82 (19%) in their third LN flare. There were significant differences in LN flare presentation in age, eGFR, serum albumin, pyuria and hematuria among groups. The National Institutes of Health chronicity indices and the percentage of patients with vascular lesions were higher in groups at progressive LN flares. In the adjusted analyses, complete and partial response rates decreased, as well as kidney and patient survival, at a progressive number of LN flares. No differences in the dynamic course of all surveillance laboratory parameters were observed in the first year after initial therapy among LN flare groups.

Conclusions

A progressive number of LN flares is associated with a lower response to therapy and an adverse prognosis for kidney function and patient survival.

Mer-tyrosine kinase: a novel susceptibility gene for SLE related end-stage renal disease

OBJECTIVE

Lupus nephritis (LN) is a common and severe manifestation of SLE. The genetic risk for nephritis and progression to end-stage renal disease (ESRD) in patients with LN remains unclear. Herein, we aimed to identify novel genetic associations with LN, focusing on subphenotypes and ESRD.

METHODS

We analysed genomic data on 958 patients with SLE (discovery cohort: LN=338) with targeted sequencing data from 1832 immunological pathway genes. We used an independent multiethnic cohort comprising 1226 patients with SLE (LN=603) as a replication dataset. Detailed functional annotation and functional epigenomic enrichment analyses were applied to predict functional effects of the candidate variants.

RESULTS

A genetic variant (rs56097910) within the MERTK gene was associated with ESRD in both cohorts, meta-analysis OR=5.4 (2.8 to 10.6); p=1.0×10-6. We observed decreased methylation levels in peripheral blood cells from SLE patients with ESRD, compared with patients without renal SLE (p=2.7×10-4), at one CpG site (cg16333401) in close vicinity to the transcription start site of MERTK and located in a DNAse hypersensitivity region in T and B cells. Rs56097910 is linked to altered MERTK expression in kidney tissue in public eQTL databases. Two loci were replicated for association with proliferative LN: PRDM1 (rs6924535, pmeta=1.6×10-5, OR=0.58) and APOA1BP (NAXE) (rs942960, pmeta=1.2×10-5, OR=2.64).

CONCLUSION

We identified a novel genetic risk locus, MERTK, associated with SLE-ESRD using the data from two large SLE cohorts. Through DNA methylation analysis and functional annotation, we showed that the risk could be mediated through regulation of gene expression. Our results suggest that variants in the MERTK gene are important for the risk of developing SLE-ESRD and suggest a role for PRDM1 and APOA1BP in proliferative LN.

Long-Term Outcomes of Children and Adolescents With Biopsy-Proven Childhood-Onset Lupus Nephritis

Introduction

Long-term data pertaining to childhood-onset lupus nephritis (cLN) remain extremely scarce.

Methods

We conducted a retrospective cohort study of biopsy-proven cLN with onset age <18 years diagnosed from 2001 to 2020 to ascertain the long-term patient and kidney survival rates, and the incidence of advanced chronic kidney disease (CKD) (estimated glomerular filtration rate [eGFR] <60 ml/min per 1.73 m²).

Results

A total of 92 subjects (78 female; age 13.7 ± 3.3 years; all Chinese) were included, with follow-up duration of 10.3 years (interquartile range, 5.8-15.9). Of these, 83 children (90%) had proliferative lupus nephritis (LN) (Class III/IV ± V). Mycophenolate was used for induction in 36%, whereas 34% received cyclophosphamide (CYC); 55% received mycophenolate as maintenance immunosuppression. The rates of complete remission (CR) and partial remission (PR) at 6 months and 12 months, respectively, were 65% and 20% and 78% and 8%. Two patients died (mortality rate 2.1/1000 patient-years), with a standardized mortality ratio of 22.3. Three patients (3.2%) developed end-stage kidney disease (ESKD), and advanced CKD occurred in 5 patients (5.4%). Survival rates without advanced CKD, ESKD, or death were 96.7%, 94.2%, 92.7%, 83.2% and 83.2% at 1 year, 5 years, 10 years, 15 years, and 20 years, respectively. Multivariate analysis revealed that severe kidney failure necessitating dialysis at presentation (adjusted hazard ratio 37.7, 95% confidence interval [CI] 4.0-355.6, P = 0.002), nonresponse (NR) after 12 months of treatment (adjusted hazard ratio 11.2, 95% CI 2.3-54.9, P = 0.003), and multiple nephritis flares (adjusted hazard ratio 2.6, 95% CI 1.1-6.2, P = 0.03) were predictive of advanced CKD, ESKD, or death. Other adverse outcomes included infections (2.9 episodes/100 patient-years), osteopenia (32%), hypertension (17%), short stature (14%), and avascular necrosis (7%).

Conclusion

The long-term outcomes of cLN appeared to have improved in the present era with effective immunosuppression, cautious drug tapering, and assurance of medication adherence. There is still an unacceptably high prevalence of adverse outcomes.

Novel and emerging treatment strategies for lupus nephritis

INTRODUCTION

Lupus nephritis (LN) is a key predictor for kidney failure and death in patients with systemic lupus erythematosus (SLE). While conventional immunosuppressive treatments have improved the outcome of LN, novel therapies continue to emerge. These new agents target specific immune-reactive cells (B cell repertoire or T lymphocytes) and crucial cytokines/signalling pathways in LN pathogenesis.

AREAS COVERED

New therapeutic approaches that target specific immune-reactive cells (B cell repertoire or T lymphocytes), crucial cytokines and their signalling pathways in LN pathogenesis.

EXPERT OPINION

Although earlier studies of rituximab fail to show benefit, a newer generation anti-CD20 biologic, obinutuzumab, is promising in LN. Inhibition of B-cell activating factor by belimumab confers superior renal response when added to the standard of care (SOC) regimens, leading to its recent approval for LN. Therapies targeting plasma cells (proteasome inhibitors, anti-CD38) in LN are being developed. A newer generation calcineurin inhibitor, voclosporin, when combined with SOC, results in better renal responses in LN. Other innovative strategies include targeting type I interferon, co-stimulatory signals, complement cascade (anti-C5b) and intracellular proliferation signals (e.g. mTOR, JAK1/2, BTK). While these novel agents improve the short-term renal responses without increased toxicities, long-term data on disease progression and safety remain to be established. Patient stratification by clinical phenotypes, biomarkers and molecular profiles helps enhance the efficacy and cost-effectiveness of novel therapies of LN.

Genome-wide association study of SNP- and gene-based approaches to identify susceptibility candidates for lupus nephritis in the Han Chinese population

Background

Lupus nephritis (LN) is one of the most common and serious complications of systemic lupus erythaematosus (SLE). Genetic factors play important roles in the pathogenesis of LN and could be used to predict who might develop LN. The purpose of this study was to screen for susceptible candidates of LN across the whole genome in the Han Chinese population.

Methods

592 LN patients and 453 SLE patients without renal damage were genotyped at 492,970 single nucleotide polymorphisms (SNPs) in the genome-wide association study (GWAS). Fifty-six SNPs were selected for replication in an independent cohort of 188 LN and 171 SLE without LN patients. Further quantitative real-time (qRT) PCR was carried out in 6 LN patients and 6 healthy controls. Gene-based analysis was conducted using the versatile gene-based test for GWAS. Subsequently, enrichment and pathway analyses were performed in the DAVID database.

Results

The GWAS analysis and the following replication research identified 9 SNPs showing suggestive correlation with LN (P&lt;10-4). The most significant SNP was rs12606116 (18p11.32), at P=8.72×10−6. The qRT-PCR results verified the mRNA levels of LINC00470 and ADCYAP1, the closest genes to rs12606116, were significantly lower in LN patients. From the gene-based analysis, 690 genes had suggestive evidence of association (P&lt;0.05), including LINC00470. The enrichment analysis identified the involvement of transforming growth factor beta (TGF-β) signalings in the development of LN. Lower plasma level of TGF-β1 (P&lt;0.05) in LN patients and lower expression of transforming growth factor beta receptor 2 in lupus mice kidney (P&lt;0.05) futher indicate the involvement of TGF-β in LN.

Conclusions

Our analyses identified several promising susceptibility candidates involved in LN, and further verification of these candidates was necessary.

Urinary serpin-A3 is an early predictor of clinical response to therapy in patients with proliferative lupus nephritis

We have previously reported that urinary excretion of serpin-A3 (uSerpA3) is significantly elevated in patients with active lupus nephritis (LN). Here, we evaluated the course of uSerpA3 during the first year of treatment and its association with response to therapy in patients with proliferative LN. The observational longitudinal study included 60 Mexican adults with proliferative LN followed during the first year after LN flare. uSerpA3 was detected by Western blot analysis at flare and after 3, 6, and 12 mo. The response to therapy was determined 1 yr after the LN flare. We evaluated the correlation between uSerpA3 and histological parameters at LN flare. The temporal association between uSerpA3 and response to therapy was analyzed with linear mixed models. uSerpA3 prognostic performance for response was evaluated with receiver-operating characteristic curves. Among the 60 patients studied, 21 patients (35%) were class III and 39 patients (65%) were class IV. uSerpA3 was higher in class IV than in class III LN (6.98 vs. 2.89 dots per in./mg creatinine, P = 0.01). Furthermore, uSerpA3 correlated with the histological activity index (r = 0.29, P = 0.02). There was a significant association between the temporal course of uSerpA3 and response to therapy. Responders showed a significant drop in uSerpA3 at 6 mo compared with LN flare (P < 0.001), whereas nonresponders persisted with elevated uSerpA3. Moreover, uSerpA3 was significantly lower at flare in responders compared with nonresponders (2.69 vs. 6.98 dots per in./mg creatinine, P < 0.05). Furthermore, uSerpA3 was able to identify nonresponders since 3 mo after LN flare (area under the curve: 0.77). In conclusion, uSerpA3 is an early indicator of kidney inflammation and predictor of the clinical response to therapy in patients with proliferative LN.NEW & NOTEWORTHY LN requires aggressive immunosuppression to improve long-term outcomes. Current indicators of remission take several months to normalize, prolonging treatment regiments in some cases. Serpin-A3 is present in urine of patients with proliferative LN. We evaluated the excretion of serpin-A3 in serial samples of patients with proliferative LN during the first year after flare. We found that uSerpA3 correlates with kidney inflammation and its decline at early points predicts the response to therapy 1 yr after flare.

Sex differences in systemic lupus erythematosus (SLE): an inception cohort of the Chinese SLE Treatment and Research Group (CSTAR) registry XVII

BACKGROUND

The onset and clinical presentation of systemic lupus erythematosus (SLE) are sex-related. Few studies have investigated the distinctions in clinical characteristics and treatment preferences in male and female SLE patients in the initial cohort. This study aimed to improve the understanding of Chinese SLE patients by characterizing the different sexes of SLE patients in the inception cohort.

METHODS

Based on the initial patient cohort established by the Chinese SLE Treatment and Research Group, a total of 8713 patients (795 men and 7918 women) with newly diagnosed SLE were enrolled between April 2009 and March 2021. Of these, 2900 patients (347 men and 2553 women) were eligible for lupus nephritis (LN). A cross-sectional analysis of the baseline demographic characteristics, clinical manifestations, laboratory parameters, organ damage, initial treatment regimens, and renal pathology classification was performed according to sex.

RESULTS

In the SLE group, as compared to female patients, male patients had a later age of onset (male vs. female: 37.0 ± 15.8 years vs. 35.1 ± 13.7 years, P  = 0.006) and a higher SLE International Collaborative Clinic/American College of Rheumatology damage index score (male vs. female: 0.47 ± 1.13 vs. 0.34 ± 0.81, P  = 0.015), LN (male vs. female: 43.6% vs. 32.2%, P < 0.001), fever (male vs. female: 18.0% vs. 14.6%, P  = 0.010), thrombocytopenia (male vs. female: 21.4% vs. 18.5%, P  = 0.050), serositis (male vs. female: 14.7% vs. 11.7%, P  = 0.013), renal damage (male vs. female: 11.1% vs. 7.4%, P < 0.001), and treatment with cyclophosphamide (CYC) (P < 0.001). The frequency of leukopenia (male vs. female: 20.5% vs. 25.4%, P  = 0.002) and arthritis (male vs. female: 22.0% vs. 29.9%, P < 0.001) was less in male patients with SLE. In LN, no differences were observed in disease duration, SLE Disease Activity Index score, renal biopsy pathological typing, or 24-h urine protein quantification among the sexes. In comparisons with female patients with LN, male patients had later onset ages (P  = 0.026), high serum creatinine (P < 0.001), higher end-stage renal failure rates (P  = 0.002), musculoskeletal damage (P  = 0.023), cardiovascular impairment (P  = 0.009), and CYC use (P  = 0.001); while leukopenia (P  = 0.017), arthritis (P  = 0.014), and mycophenolate usage (P  = 0.013) rates were lower.

CONCLUSIONS

Male SLE patients had more severe organ damage and a higher LN incidence compared with female SLE patients; therefore, they may require more aggressive initial treatment compared to female patients.

Predictors of infection requiring hospitalization in patients with systemic lupus erythematosus: a time-to-event analysis

OBJECTIVES

To evaluate the predictors of serious infection in patients with systemic lupus erythematosus (SLE).

METHODS

Serious infections were identified in SLE patients in a prospectively-followed single centre cohort. Associations of serious infection with disease-related variables and medication use were analysed using Cox and related regression models.

RESULTS

346 patients were followed for a mean (SD) of 6.6 (3.7) years. 86 episodes of serious infection were observed, with an incidence rate of 3.8 episodes per 100 person-years. Patients who had serious infection had higher baseline SLE Damage Index (SDI) and Charlston Comorbidity Index (CCI); they were also more likely to have high disease activity status (HDAS), and higher disease activity in multiple clinical domains, higher flare rates, higher time-adjusted prednisolone dose exposure, and less time in lupus low disease activity state (LLDAS). Patients who have received cyclophosphamide, rituximab and mycophenolate were more likely to have experienced serious infection. After multivariable adjustment in Cox regression analysis, cyclophosphamide, higher SDI score, and higher disease activity were associated with an increased hazard of first serious infection. History of previous serious infection conferred the highest risk. Lymphopenia was also a modest but statistically significant predictor of serious infection.

CONCLUSION

History of previous serious infection was the strongest predictor of serious infection in our SLE cohort. This study also suggests that clinical factors such as damage accrual, disease activity, and choice of immunosuppressant, can each have an independent risk in predicting serious infection particularly the first episode.

GBP2 acts as a member of the interferon signalling pathway in lupus nephritis

Lupus nephritis (LN) is a common and serious clinical manifestation of systemic lupus erythematosus. However, the pathogenesis of LN is not fully understood. The currently available treatments do not cure the disease and appear to have a variety of side effects in the long term. The purpose of this study was to search for key molecules involved in the LN immune response through bioinformatics techniques to provide a reference for LN-specific targeted therapy. The GSE112943 dataset was downloaded from the Gene Expression Omnibus database, and 20 of the samples were selected for analysis. In total, 2330 differentially expressed genes were screened. These genes were intersected with a list of immune genes obtained from the IMMPORT immune database to obtain 128 differentially expressed immune-related genes. Enrichment analysis showed that most of these genes were enriched in the interferon signalling pathway. Gene set enrichment analysis revealed that the sample was significantly enriched for expression of the interferon signalling pathway. Further analysis of the core gene cluster showed that nine genes, GBP2, VCAM1, ADAR, IFITM1, BST2, MX2, IRF5, OAS1 and TRIM22, were involved in the interferon signalling pathway. According to our analysis, the guanylate binding protein 2 (GBP2), interferon regulatory factor 5 and 2′-5′-oligoadenylate synthetase 1 (OAS1) genes are involved in three interferon signalling pathways. At present, we do not know whether GBP2 is associated with LN. Therefore, this study focused on the relationship between GBP2 and LN pathogenesis. We speculate that GBP2 may play a role in the pathogenesis of LN as a member of the interferon signalling pathway. Further immunohistochemical results showed that the expression of GBP2 was increased in the renal tissues of LN patients compared with the control group, confirming this conjecture. In conclusion, GBP2 is a member of the interferon signalling pathway that may have implications for the pathogenesis of LN and serves as a potential biomarker for LN.