Chapter 12: Lupus nephritis

Renal disease in pediatric rheumatology

PURPOSE OF REVIEW

This review will provide updates in the outcomes in the common rheumatologic diseases with kidney involvement. Covered are also advances in therapeutics for the use of pediatric rheumatologic diseases with kidney involvement, as well as the potential kidney complications from other rheumatologic diseases and their medications.

RECENT FINDINGS

Two of the more common rheumatologic diseases with kidney involvement, lupus and vasculitis, continue to show inadequate response to initial therapy of renal disease and practice continues to be driven by results of adult studies.

SUMMARY

There is a continued need for pediatric specific studies in rheumatologic diseases with kidney involvement as outcomes continue to be inadequate. Despite recently approved treatments for adults with rheumatic diseases and kidney involvement, therapeutic options in pediatrics remain limited, contributing to the overall morbidity and mortality.

Deep learning model to predict lupus nephritis renal flare based on dynamic multivariable time-series data

OBJECTIVES

To develop an interpretable deep learning model of lupus nephritis (LN) relapse prediction based on dynamic multivariable time-series data.

DESIGN

A single-centre, retrospective cohort study in China.

SETTING

A Chinese central tertiary hospital.

PARTICIPANTS

The cohort study consisted of 1694 LN patients who had been registered in the Nanjing Glomerulonephritis Registry at the National Clinical Research Center of Kidney Diseases, Jinling Hospital from January 1985 to December 2010.

METHODS

We developed a deep learning algorithm to predict LN relapse that consists of 59 features, including demographic, clinical, immunological, pathological and therapeutic characteristics that were collected for baseline analysis. A total of 32 227 data points were collected by the sliding window method and randomly divided into training (80%), validation (10%) and testing sets (10%). We developed a deep learning algorithm-based interpretable multivariable long short-term memory model for LN relapse risk prediction considering censored time-series data based on a cohort of 1694 LN patients. A mixture attention mechanism was deployed to capture variable interactions at different time points for estimating the temporal importance of the variables. Model performance was assessed according to C-index (concordance index).

RESULTS

The median follow-up time since remission was 4.1 (IQR, 1.7-6.7) years. The interpretable deep learning model based on dynamic multivariable time-series data achieved the best performance, with a C-index of 0.897, among models using only variables at the point of remission or time-variant variables. The importance of urinary protein, serum albumin and serum C3 showed time dependency in the model, that is, their contributions to the risk prediction increased over time.

CONCLUSIONS

Deep learning algorithms can effectively learn through time-series data to develop a predictive model for LN relapse. The model provides accurate predictions of LN relapse for different renal disease stages, which could be used in clinical practice to guide physicians on the management of LN patients.

Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

Distinct transcriptomic and metabolomic profiles characterize NSAID-induced urticaria/angioedema patients undergoing aspirin desensitization

BACKGROUND

There is limited data on the mechanisms of aspirin desensitization in patients with nonsteroidal anti-inflammatory drug (NSAID)-induced urticaria/angioedema (NIUA).

OBJECTIVES

We sought to characterize the transcriptomic and metabolomic profiles of patients with NIUA undergoing aspirin desensitization.

METHODS

PBMCs and plasma were separated from the blood of patients with NIUA undergoing aspirin desensitization for coronary artery disease and NSAID-tolerant controls. RNA was isolated from PBMCs and subjected to messenger RNA (mRNA)- and long noncoding RNA (lncRNA)-sequencing. Plasma samples were analyzed using LC-MS/MS for metabolite shifts using a semitargeted metabolomics panel.

RESULTS

Eleven patients with NIUA and 10 healthy controls were recruited. The mRNA gene profiles of predesensitization versus postdesensitization and healthy control versus postdesensitization did not differ significantly. However, we identified 739 mRNAs and 888 lncRNAs as differentially expressed from preaspirin desensitization patients and controls. A 12-mRNA gene signature was trained using a machine learning algorithm to distinguish between controls, postdose, and predose samples. Ingenuity Pathway Analysis identified 5 canonical pathways that were significantly enriched in preaspirin desensitization samples. IL-22 was the most upregulated pathway. To investigate the potential regulatory roles of the differentially expressed lncRNA on the mRNAs, 9 lncRNAs and 12 mRNAs showed significantly correlated expression patterns in the IL-22 pathway. To validate the transcriptomics data, IL-22 was measured in the plasma samples of the subjects using ELISA. IL-22 was significantly higher in preaspirin desensitization patients compared with controls. In parallel, metabolomic analysis revealed stark differences in plasma profiles of preaspirin desensitization patients and healthy controls. In particular, 2-hydroxybenzoic acid (salicylic acid) was significantly lower in preaspirin desensitization patients compared with healthy controls.

CONCLUSIONS

This is the first study to combine both transcriptomic and metabolomic approaches in patients with NIUA, which contributes to a deeper understanding about the pathogenesis of NIUA and may potentially pave the way toward a molecular diagnosis of NSAID hypersensitivity.

A Long-Term follow-up Study of Lupus Nephritis in a Single Tertiary Care Centre

Introduction

Lupus nephritis (LN) is an immune complex glomerulonephritis, which is a very serious complication of systemic lupus erythematosus (SLE) as it can progress to end-stage kidney disease (ESKD).

Methods

In this study of 92 renal biopsy-proven LN, the patients were followed up for a minimum period of 2 years with a mean follow-up period of 5.4 ± 3.4 years.

Results

The mean serum creatinine of our study population was 1.4 ± 1.53. Our study population included 2 patients with class I lesions, 5 with class II, 22 with Class III, 53 with Class IV, and 10 with Class V lesions. Our therapeutic approach included only oral steroids for class I and class II lesions; for class III, IV, and V lesions, our approach included pulse steroids followed by oral steroids with either intravenous (IV) monthly cyclophosphamide (CYC) or mycophenolate mofetil (MMF). For maintenance, azathioprine or MMF were used along with low-dose oral steroids after 6 months of CYC or MMF. In CYC induction group containing 78 patients (84.7%), 66 patients (84.6%) attained remission (CR + PR), relapse in five patients (6.4%), ESRD on HD in five patients (6.4%), and death in two patients (2.6%).

Conclusion

At the end of the study, in all groups, 79 patients (85.86%) were in remission (CR + PR), six patients (6.5%) were in relapse, five patients (5.4%) had reached the ESKD stage on HD, and two patients (2.2%) died.

Predicting treatment response and clinicopathological findings in lupus nephritis with urine epidermal growth factor, monocyte chemoattractant protein-1 or their ratios

Introduction

There is a need for sensitive and specific biomarkers to predict kidney damage and therapeutic response in lupus nephritis (LN). Monocyte chemoattractant protein-1 (MCP-1) and epidermal growth factor (EGF) are cytokines with divergent roles. EGF or EGF/MCP1 ratio have been shown to correlate with prognosis in primary glomerulonephritis, but there is limited information in lupus nephritis (LN). This study evaluated the roles of MCP-1, EGF or their ratio as biomarkers of histopathology and response to treatment in LN.

Methods

This was a cross-sectional and observational study. Baseline urine MCP-1 and EGF levels in systemic lupus erythematosus (SLE) patients and controls (total n = 101) were compared, and levels were correlated with clinicopathological findings and subsequent response to treatment.

Results

MCP-1 was higher in active LN (n = 69) compared to other SLE groups and controls, whereas EGF was not different. MCP-1 correlated with disease activity (proteinuria, renal SLEDAI, classes III/IV/V, and high activity index.) By contrast, EGF correlated with eGFR, but not with proteinuria, activity index, or class III/IV/V. MCP-1 was higher, and EGF was lower in high chronicity index. EGF/MCP-1 decreased with greater clinicopathological severity. In a subgroup with proliferative LN who completed six months of induction therapy (n = 41), EGF at baseline was lower in non-responders compared to responders, whereas MCP-1 was similar. By multivariable analysis, baseline EGF was independently associated with subsequent treatment response. Area under the curve for EGF to predict response was 0.80 (0.66–0.95). EGF ≥ 65.6 ng/ mgCr demonstrated 85% sensitivity and 71% specificity for response. EGF/MCP-1 did not improve the prediction for response compared to EGF alone.

Conclusion

MCP-1 increased with disease activity, whereas EGF decreased with low GFR and chronic damage. Urine EGF may be a promising biomarker to predict therapeutic response in LN. EGF/MCP-1 did not improve the prediction of response.

Glycol chitosan-based tacrolimus-loaded nanomicelle therapy ameliorates lupus nephritis

Background

Recently, we developed hydrophobically modified glycol chitosan (HGC) nanomicelles loaded with tacrolimus (TAC) (HGC-TAC) for the targeted renal delivery of TAC. Herein, we determined whether the administration of the HGC-TAC nanomicelles decreases kidney injury in a model of lupus nephritis. Lupus-prone female MRL/lpr mice were randomly assigned into three groups that received intravenous administration of either vehicle control, an equivalent dose of TAC, or HGC-TAC (0.5 mg/kg TAC) weekly for 8 weeks. Age-matched MRL/MpJ mice without Fas^lpr mutation were also treated with HGC vehicle and used as healthy controls.

Results

Weekly intravenous treatment with HGC-TAC significantly reduced genetically attributable lupus activity in lupus nephritis-positive mice. In addition, HGC-TAC treatment mitigated renal dysfunction, proteinuria, and histological injury, including glomerular proliferative lesions and tubulointerstitial infiltration. Furthermore, HGC-TAC treatment reduced renal inflammation and inflammatory gene expression and ameliorated increased apoptosis and glomerular fibrosis. Moreover, HGC-TAC administration regulated renal injury via the TGF-β1/MAPK/NF-κB signaling pathway. These renoprotective effects of HGC-TAC treatment were more potent in lupus mice compared to those of TAC treatment alone.

Conclusion

Our study indicates that weekly treatment with the HGC-TAC nanomicelles reduces kidney injury resulting from lupus nephritis by preventing inflammation, fibrosis, and apoptosis. This advantage of a new therapeutic modality using kidney-targeted HGC-TAC nanocarriers may improve drug adherence and provide treatment efficacy in lupus nephritis mice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00857-w.

Performance of the 2019 EULAR/ACR systemic lupus erythematosus classification criteria in a cohort of patients with biopsy-confirmed lupus nephritis

OBJECTIVE

To evaluate the performance of the European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) SLE classification criteria in a cohort of patients with biopsy-confirmed lupus nephritis (LN) and their renal prognosis.

METHODS

Patients with newly diagnosed SLE attending and followed up for >12 months were included. A retrospective review of all patients with renal biopsy fulfilling a consensus expert opinion during 2014 and 2018. Clinical, serological and pathological data were collected and each patient was assigned a high/low criteria scores (HS/LS) group. Survival curves for flare adjusted for multiplicity on renal flares, was applied to the two groups.

RESULTS

Applying EULAR/ACR criteria in our cohort of 126 patients, 6 (4.76%) did not meet the criterion, resulting in a sensitivity of 95.24%. The EULAR/ACR criteria scores was positively correlated with SLE disease activity index scores. Additionally, we noticed that a significant difference in clinical and immunological manifestations between HS and LS group. We observed a higher proportions of class Ⅲ or Ⅳ LN and lower proportions of class Ⅱ or V LN (p=0.034) and pathological higher activity index in HS group (p=0.007). Compared with LS groups, patients involved more severe renal damage and achieved higher rate of complete remission in the HS group. The Kaplan-Meier exploratory analyses, adjusted for LN classification, estimated glomerular filtration rate, activity index and chronicity index and induction and maintenance treatments, showed that patients in the HS group had a tendency of higher renal flare risk than that in the LS group (HR=0.21, p=0.04).

CONCLUSIONS

The EULAR/ACR criteria performed high sensitivity in identifying SLE in this cohort of biopsy-confirmed LN. Patients with LN with high criteria scores had more extrarenal manifestations, and worse renal prognosis in the short and long terms.

Safety and effectiveness of transjugular renal biopsy for systemic lupus erythematosus and antiphospholipid antibody syndrome patients taking antithrombotics

BACKGROUND

Renal biopsy is the cornerstone of systemic lupus erythematosus (SLE) nephritis and antiphospholipid syndrome (APS) nephropathy management. However, transcutaneous renal biopsy (TCRB) is hampered by the antithrombotic treatment frequently prescribed for those diseases. Transjugular renal biopsy (TJRB) offers an attractive alternative for patients at increased risk of bleeding. The primary objective of the study was to describe the safety profile and diagnostic performance of TJRB in SLE and APS patients.

METHODS

All SLE and/or APS patients who underwent a renal biopsy in our department (between January 2004 and October 2016) were retrospectively reviewed. Major complications were death, haemostasis nephrectomy, renal artery embolization, red blood cell transfusion, sepsis and vascular thrombosis; macroscopic haematuria, symptomatic perirenal/retroperitoneal bleeding and renal arteriovenous fistula without artery embolization were considered as minor complications.

RESULTS

Two hundred and fifty-six TJRBs-119 without antithrombotics (untreated), 69 under aspirin and 68 on anticoagulants and 54 TCRBs without antithrombotics-were analysed. Their major and minor complication rates, respectively, did not differ significantly for the four groups: 0 and 8% for untreated TJRBs, 1 and 6% for aspirin-treated, 6 and 10% for anticoagulant-treated and 2 and 2% for TCRBs. The number of glomeruli sampled and the biopsy contribution to establishing a histological diagnosis was similar for the four groups.

CONCLUSIONS

TJRBs obtained from SLE and APS patients taking antithrombotics had diagnostic yields and safety profiles similar to those of untreated TCRBs. Thus, TJRB should be considered for SLE and APS patients at risk of bleeding.

Clinicopathological characteristics and outcome of patients with fibrillary glomerulonephritis: DNAJB9 is a valuable histologic marker

BACKGROUND

Fibrillary glomerulonephritis (FGN) is a rare glomerular disease. DNAJB9 as a new reliable diagnostic marker for the diagnosis of FGN was discovered recently. To investigate the clinicopathological features and prognosis of DNAJB9-positive FGN, we report on a case series in a single center in China.

METHODS

DNAJB9 immunohistochemistry was performed on renal biopsy samples from patients with FGN (n = 7), and non-FGN glomerular diseases (n = 27) were used as controls. The patients with DNAJB9-positive FGN were retrospectively analyzed.

RESULTS

Strong DNAJB9 staining of glomerular extracellular deposits was observed in 6 cases of originally diagnosed FGN. One man and 5 women with a median age of 26 years were studied. The patients presented with renal insufficiency in 1 case, proteinuria in 6 cases, nephrotic syndrome in 3 cases, and microscopic hematuria in 2 cases. The histologic pattern was mesangial proliferative glomerulonephritis in 1 case and membranoproliferative glomerulonephritis in 5 cases. The glomerular deposits stained for polytypic IgG and both kappa and lambda in 3 cases, polytypic IgG without kappa or lambda in 1, monotypic IgG1-kappa in 1 and IgG1-lambda in 1. Extraglomerular deposits were identified in all cases. Congo red positivity was observed in 3 cases. All of the patients received renin-angiotensin-aldosterone system blockade and 5 of them received glucocorticoid and/or immunosuppression. At a median time of 36.2 months after biopsy, 2 cases had partial remission, 3 cases displayed no remission, and 1 case progressed to end-stage renal disease.

CONCLUSIONS

Extraglomerular deposits in the FGN were common. Monotypic FGN was found in young patients with a favorable renal outcome.

Artificial intelligence and machine learning in nephropathology

Artificial intelligence (AI) for the purpose of this review is an umbrella term for technologies emulating a nephropathologist's ability to extract information on diagnosis, prognosis, and therapy responsiveness from native or transplant kidney biopsies. Although AI can be used to analyze a wide variety of biopsy-related data, this review focuses on whole slide images traditionally used in nephropathology. AI applications in nephropathology have recently become available through several advancing technologies, including (i) widespread introduction of glass slide scanners, (ii) data servers in pathology departments worldwide, and (iii) through greatly improved computer hardware to enable AI training. In this review, we explain how AI can enhance the reproducibility of nephropathology results for certain parameters in the context of precision medicine using advanced architectures, such as convolutional neural networks, that are currently the state of the art in machine learning software for this task. Because AI applications in nephropathology are still in their infancy, we show the power and potential of AI applications mostly in the example of oncopathology. Moreover, we discuss the technological obstacles as well as the current stakeholder and regulatory concerns about developing AI applications in nephropathology from the perspective of nephropathologists and the wider nephrology community. We expect the gradual introduction of these technologies into routine diagnostics and research for selective tasks, suggesting that this technology will enhance the performance of nephropathologists rather than making them redundant.

Fibrillary Glomerulonephritis: Clinicopathologic Features and Atypical Cases from a Multi-Institutional Cohort

BACKGROUND AND OBJECTIVES

Fibrillary GN has been defined as an immune complex-mediated GN with amyloid-like fibrils larger than amyloid which are IgG positive and Congo red negative. With discovery of DNAJB9 as a highly sensitive and specific marker for fibrillary GN, the specificity of the morphologic criteria for establishing the diagnosis of fibrillary GN has come into question.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We sought to (1) determine anatomic characteristics that best define fibrillary GN and (2) identify clinical and pathologic features that predict outcomes.

RESULTS

We retrospectively reviewed kidney biopsies from patients diagnosed with fibrillary GN or suspected fibrillary GN between 1997 and 2017 (n=266, 65% female, median age 61). Approximately 11% of kidney biopsies had one or more unusual feature including monotypic deposits, Congo red positivity, or unusual fibril diameter. Fibrillary GN as a possible monoclonal gammopathy of renal significance represented <1% of cases. Immunostaining for DNAJB9 confirmed fibrillary GN in 100% of cases diagnosed as fibrillary GN and 79% of atypical cases diagnosed as possible fibrillary GN. At a median time of 24 months (interquartile range, 8-46 months) after biopsy (n=100), 53% of patients reached the combined primary outcome of ESKD or death, 18% had CKD, and 18% had partial remission. On multivariable analysis, male sex (adjusted hazard ratio [aHR], 3.82; 95% confidence interval [95% CI], 1.97 to 7.37) and eGFR were the most significant predictors of primary outcome (aHR of 8.02 if eGFR <30 ml/min per 1.73 m2 [95% CI, 1.85 to 34.75]; aHR of 6.44 if eGFR 30 to <45 ml/min per 1.73 m2 [95% CI, 1.38 to 29.99]). Immunosuppressive therapy with rituximab was significantly associated with stabilization of disease progression.

CONCLUSIONS

Detection of DNAJB9 is a useful diagnostic tool for diagnosing atypical forms of fibrillary GN. The outcomes for fibrillary GN are poor and progression to ESKD is influenced predominantly by the degree of kidney insufficiency at the time of diagnosis and male sex. Rituximab may help preserve kidney function for select patients with fibrillary GN.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2019_11_04_CJN03870319.mp3.

Longitudinal associations of active renal disease with irreversible organ damage accrual in systemic lupus erythematosus

Objective

To examine longitudinal associations of active lupus nephritis with organ damage accrual in patients with systemic lupus erythematosus (SLE).

Methods

This study was performed using data from a large multinational prospective cohort. Active lupus nephritis at any visit was defined by the presence of urinary casts, proteinuria, haematuria or pyuria, as indicated by the cut-offs in the SLE Disease Activity Index (SLEDAI)-2K, collected at each visit. Organ damage accrual was defined as a change of SLICC-ACR Damage Index (SDI) score >0 units between baseline and final annual visits. Renal damage accrual was defined if there was new damage recorded in renal SDI domains (estimated glomerular filtration rate <50%/proteinuria >3.5 g per 24 h/end-stage kidney disease). Time-dependent hazard regression analyses were used to examine the associations between active lupus nephritis and damage accrual.

Results

Patients ( N = 1735) were studied during 12,717 visits for a median (inter-quartile range) follow-up period of 795 (532, 1087) days. Forty per cent of patients had evidence of active lupus nephritis at least once during the study period, and active lupus nephritis was observed in 3030 (24%) visits. Forty-eight per cent of patients had organ damage at baseline and 14% accrued organ damage. Patients with active lupus nephritis were 52% more likely to accrue any organ damage compared with those without active lupus nephritis (adjusted hazard ratio = 1.52 (95% confidence interval (CI): 1.16, 1.97), p < 0.02). Active lupus nephritis was strongly associated with damage accrual in renal but not in non-renal organ domains (hazard ratios = 13.0 (95% CI: 6.58, 25.5) p < 0.001 and 0.96 (95% CI: 0.69, 1.32) p = 0.8, respectively). There was no effect of ethnicity on renal damage accrual, but Asian ethnicity was significantly associated with reduced non-renal damage accrual.

Conclusion

Active lupus nephritis measured using the SLEDAI-2K domain cut-offs is associated with renal, but not non-renal, damage accrual in SLE.

Utilization of Biomarkers in Lupus Nephritis

Lupus nephritis (LN) occurs in up to 60% of SLE patients, and is a leading cause of disability and death. Current treatment of LN consists of a combination of high dose corticosteroids that non-specifically decrease inflammation and cytotoxic medications that reduce auto-antibody production. That combination of therapy is associated with significant side effects while remission rates remain inadequate. Since the introduction of biologics into the pharmacological armamentarium, there has been hope for less toxic and more effective therapies for LN. Unfortunately, after multiple clinical trials, no biologic has improved efficacy over standard of care therapies for LN. This is likely, in part, due to disease heterogeneity. The utilization of biomarkers in LN may provide a way to stratify patients and guide therapeutic options. In this review, we summarize traditional and novel LN biomarkers and discuss how they may be used to diagnose, stratify, and guide therapy in patients with LN, bringing precision medicine to the forefront of LN therapy.

Real-world electronic health record identifies antimalarial underprescribing in patients with lupus nephritis

Antimalarials (AMs) reduce disease activity and improve survival in patients with systemic lupus erythematosus (SLE), but studies have reported low AM prescribing frequencies. Using a real-world electronic health record cohort, we examined if patient or provider characteristics impacted AM prescribing. We identified 977 SLE cases, 94% of whom were ever prescribed an AM. Older patients and patients with SLE nephritis were less likely to be on AMs. Current age (odds ratio = 0.97, p < 0.01) and nephritis (odds ratio = 0.16, p < 0.01) were both significantly associated with ever AM use after adjustment for sex and race. Of the 244 SLE nephritis cases, only 63% were currently on AMs. SLE nephritis subjects who were currently prescribed AMs were more likely to be followed by a rheumatologist than a nephrologist and less likely to have undergone dialysis or renal transplant (both p < 0.001). Non-current versus current SLE nephritis AM users had higher serum creatinine (p < 0.001), higher urine protein (p = 0.05), and lower hemoglobin levels (p < 0.01). As AMs reduce disease damage and improve survival in patients with SLE, our results demonstrate an opportunity to target future efforts to improve prescribing rates among multi-specialty providers.

Outcomes following mycophenolate mofetil versus cyclophosphamide induction treatment for proliferative juvenile-onset lupus nephritis

Background

Juvenile-onset systemic lupus erythematosus (JSLE) is more severe than adult-onset disease, including more lupus nephritis (LN). Despite differences in phenotype/pathogenesis, treatment is based upon adult trials. This study aimed to compare treatment response, damage accrual, time to inactive LN and subsequent flare, in JSLE LN patients treated with mycophenolate mofetil (MMF) versus intravenous cyclophosphamide (IVCYC).

Methods

UK JSLE Cohort Study participants, ≤16 years at diagnosis, with ≥4 American College of Rheumatology criteria for SLE, with class III or IV LN, were eligible. Mann–Whitney U tests, Fisher's exact test and Chi-squared tests were utilized for statistical analysis.

Results

Of the patients, 34/51 (67%) received MMF, and 17/51 (33%) received IVCYC. No significant differences were identified at 4–8 and 10–14 months post-renal biopsy and last follow-up, in terms of renal British Isles Lupus Assessment Grade scores, urine albumin/creatinine ratio, serum creatinine, ESR, anti-dsDNA antibody, C3 levels and patient/physician global scores. Standardized Damage Index scores did not differ between groups at 13 months or at last follow-up. Inactive LN was attained 262 (141–390) days after MMF treatment, and 151 (117–305) days following IVCYC ( p = 0.17). Time to renal flare was 451 (157–1266) days for MMF, and 343 (198–635) days for IVCYC ( p = 0.47).

Conclusion

This is the largest study to date investigating induction treatments for proliferative LN in children, demonstrating comparability of MMF and IVCYC.

Refractory lupus nephritis: a survey

‘Refractory lupus nephritis’ is a frequently used term but poorly defined. We conducted a survey among nephrologists and rheumatologists to spot the diversity of perceptions of this term and to better understand the clinical practice related to ‘refractory lupus nephritis’. A total of 145 questionnaires completed by lupus nephritis experts were available for analysis, of which 52% were nephrologists, 34% rheumatologists, and 13% internists. Response to induction treatment was mostly assessed after six months (58%), but assessment at three months was more common with the use of the EURO lupus protocol than with other treatment protocols. Rheumatologists used urinary sediment to assess response more frequently than nephrologists (66 vs. 48%, p < 0.05, Chi2), while nephrologists conversely relied significantly more on clinical symptoms (61 vs. 31%, p < 0.0001, Chi2). Non-nephrologists quantified proteinuria preferentially by 24 h urine sampling, while the majority of nephrologists relied on the urinary protein/creatinine ratio (UPCR) or the albumin/creatinine ratio of spot urine samples (59 vs. 38%, p < 0.05, Chi2). A total of 91% were concerned about persistent immunological systemic lupus erythematosus activity. There was less concern about drug adherence, renal scarring, genetic factors or other kidney diseases. Less than 20% check for drug adherence by regularly monitoring drug plasma levels. Nephrologists considered a re-biopsy more often than rheumatologists (58 vs. 38%, p < 0.05, Chi2). Together, among lupus nephritis experts there is considerable diversity in the perception of what the term ‘refractory lupus nephritis’ describes and how it is defined. A consensus definition of ‘refractory lupus nephritis’ is needed.

Investigation on the benefits of mycophenolate mofetil and therapeutic drug monitoring in the treatment of Japanese patients with lupus nephritis

BACKGROUND

Mycophenolate mofetil (MMF) is recommended as a first-line immunosuppressant to treat lupus nephritis (LN). Prognosis and therapeutic response in LN are known to vary depending on race. We investigated the benefits of MMF and therapeutic drug monitoring (TDM) in the treatment of Japanese LN patients.

METHODS

In this retrospective cohort study, a total of 20 patients with LN who started MMF treatment were included. Clinical data were collected regularly after MMF administration. We evaluated complete remission (CR) rate as the primary outcome. Predictors of CR were identified using univariate and multivariate analyses. In the research of TDM, the correlation with the area under the curve (AUC) was analyzed at MMF dose, single-point value, treatment response, and adverse events.

RESULTS

Overall, 70% of cases showed CR; both flare-ups and refractory cases had favorable results. Cases of LN with nephrotic syndrome (NS) or class III/IV + V showed a significantly lower CR rate (p < 0.005). The ratio of maintaining CR after MMF therapy was as high as 85.7%. In multivariate analysis, NS was an independent negative predictor of CR (HR 0.09, 95% confidence interval 0.01-0.81; p = 0.03). The relationship between AUC and MMF dose was low, and AUC correlated with trough level (r = 0.73). AUC tended to be high in the treatment responder (p = 0.09), but did not correlate with adverse events of infection (p = 0.92).

CONCLUSION

MMF is a beneficial treatment option for Japanese LN patients, and further investigation on TDM-based therapy is needed.

Kidney disease in primary anti-phospholipid antibody syndrome

APS is an autoimmune disease defined by the presence of arterial or venous thrombotic events and/or pregnancy morbidity in patients who test positive for aPL. APS can be isolated (primary APS) or associated with other autoimmune diseases. The kidney is a major target organ in APS, and renal thrombosis can occur at any level within the vasculature of the kidney (renal arteries, intrarenal vasculature and renal veins). Histological findings vary widely, including ischaemic glomeruli and thrombotic lesions without glomerular or arterial immune deposits on immunofluorescence. Renal involvement in patients with definite APS is treated with long-term anticoagulants as warfarin, but new treatments are being tried. The aim of this article is to review the links between primary APS and kidney disease.

Recent advances in the understanding of renal inflammation and fibrosis in lupus nephritis

Lupus nephritis is a potentially reversible cause of severe acute kidney injury and is an important cause of end-stage renal failure in Asians and patients of African or Hispanic descent. It is characterized by aberrant exaggerated innate and adaptive immune responses, autoantibody production and their deposition in the kidney parenchyma, triggering complement activation, activation and proliferation of resident renal cells, and expression of pro-inflammatory and chemotactic molecules leading to the influx of inflammatory cells, all of which culminate in destruction of normal nephrons and their replacement by fibrous tissue. Anti-double-stranded DNA (anti-dsDNA) antibody level correlates with disease activity in most patients. There is evidence that apart from mediating pathogenic processes through the formation of immune complexes, pathogenic anti-dsDNA antibodies can bind to resident renal cells and induce downstream pro-apoptotic, pro-inflammatory, or pro-fibrotic processes or a combination of these. Recent data also highlight the critical role of macrophages in acute and chronic kidney injury. Though clinically effective, current treatments for lupus nephritis encompass non-specific immunosuppression and the anti-inflammatory action of high-dose corticosteroids. The clinical and histological impact of novel biologics targeting pro-inflammatory molecules remains to be investigated. Insight into the underlying mechanisms that induce inflammatory and fibrotic processes in the kidney of lupus nephritis could present opportunities for more specific novel treatment options to improve clinical outcomes while minimizing off-target untoward effects. This review discusses recent advances in the understanding of pathogenic mechanisms leading to inflammation and fibrosis of the kidney in lupus nephritis in the context of established standard-of-care and emerging therapies.

Risk of clinical deterioration in patients with lupus nephritis receiving rituximab

Rituximab is a chimeric anti-CD20 monoclonal antibody that is used as an immunosuppressive agent in cyclophosphamide refractory lupus nephritis to induce remission. Although uncontrolled case series suggest efficacy, this is not yet supported by evidence from prospective randomized controlled trials. The objective of this retrospective case series is to report the clinical outcome of seven patients who received rituximab for lupus nephritis in a single centre between 2011 and 2014. One patient had clinical evidence of an uncomplicated response to therapy. A second patient responded well with the first rituximab course, but had transient worsening of renal function and nephrotic syndrome with a second course. The other five patients all had evidence of a clinical deterioration following rituximab. Two had transient worsening of both renal function and nephrotic syndrome, with subsequent evidence of response in one of these. A fifth patient showed evidence of worsening nephrotic syndrome and renal function which then improved but with renal function remaining below the level present before rituximab. A sixth developed rapidly progressive renal failure following rituximab with active nephritis on renal biopsy and required rescue therapy with high dose steroids and cyclophosphamide. A seventh developed a transient worsening of her nephrotic syndrome and an exacerbation of extrarenal symptoms following rituximab. The two patients showing a good response had complete B cell depletion and incomplete depletion may be a factor in the deterioration seen in the other patients. Our experience suggests that rituximab therapy in lupus nephritis is not without risk and patients should be informed of this beforehand. This is particularly important in view of the uncertainty that rituximab will offer a therapeutic benefit.

Long-term outcome of mycophenolate mofetil treatment for patients with microscopic polyangiitis: an observational study in Chinese patients

This study aimed to retrospectively analyze the long-term outcome of mycophenolate mofetil (MMF) therapy for microscopic polyangiitis (MPA) with mild to moderate renal involvement in Chinese patients. Thirty-four MPA patients (24 females, 10 males, aged 44.7 ± 17 years, BVAS score 13.8 ± 3.2, SCr 2.2 ± 1.1 mg/dl) with SCr < 5 mg/dl and who received glucocorticoids plus MMF therapy for inducing and maintaining remission were included in this study. The remission and relapse rates, patient and renal survival rates and adverse events were retrospectively analyzed. We found that 31 (91.2 %) of 34 patients achieved remission and were continuously treated with glucocorticoids plus MMF for maintaining remission. The median duration of MMF treatment was 24 months (IQR 15-53 months) and follow-up time was 86 months (IQR 29-124 months). During the follow-up, 7 (22.6 %) patients relapsed, one patient died, and one patient progressed into end-stage renal disease. The 5-year patient and renal survival rates were 92.8 and 95.2 %, respectively. 11 (32.4 %) patients suffered 16 adverse events, 13 of which were pulmonary infection. In conclusion, glucocorticoids plus MMF regimen as induction and maintenance therapy could achieve high remission rate and good long-term renal survival in MPA patients with mild to moderate renal involvement. Prospective controlled trials with a large sample size are needed to confirm the efficacy of MMF in this population.

Systemic lupus erythematosus: An update for ophthalmologists

Systemic lupus erythematosus (SLE) is a life-threatening multisystem inflammatory condition that may affect almost any part of the eye. We provide an update for the practicing ophthalmologist comprising a systematic review of the recent literature presented in the context of current knowledge of the pathogenesis, diagnosis, and treatment of this condition. We review recent advances in the understanding of the influence of genetic and environmental factors on the development of SLE. Recent changes in the diagnostic criteria for SLE are considered. We assess the potential for novel molecular biomarkers to find a clinical application in disease diagnosis and stratification and in the development of therapeutic agents. We discuss limited forms of SLE and their differentiation from other collagen vascular disorders and review recent evidence underlying the use of established and novel therapeutics in this condition, including specific implications regarding monitoring for ocular toxicity associated with antimalarials.

[Prognosis and therapy of inflammatory rheumatic diseases : Impact of renal manifestations]

BACKGROUND

Inflammatory rheumatic diseases and their treatment cause various renal manifestations requiring modification of treatment.

OBJECTIVES

Discussion of renal manifestations in selected rheumatic diseases, including their impact on general prognosis and therapy.

MATERIALS AND METHODS

Basic literature and expert opinions are analyzed and discussed.

RESULTS

Inflammatory rheumatic diseases and their treatment cause various renal manifestations, including glomerular, tubular, interstitial, and vascular damage. The type of damage determines both, associated clinical symptoms (i.e. hematuria, proteinuria, loss of kidney function) and the renal and overall survival as will be discussed here for rheumatoid arthritis, systemic lupus erythematosus, scleroderma, Sjögrens syndrome, cryoglobulinemia and ANCA-associated vasculitis.

CONCLUSION

Renal manifestations are generally indicators of high disease activity and usually require more intensive treatment of the underlying rheumatic disease. Early and rigorous treatment, which has to be adapted to renal function, is capable of improving renal and overall survival in many of the affected patients.

Glucocorticoid with or without additional immunosuppressant therapy for patients with lupus podocytopathy: a retrospective single-center study

Lupus podocytopathy is a newly recognized class of lupus nephritis characterized by extensive glomerular foot process effacement without capillary wall immune deposits. The treatment response and relapse of glucocorticoid with or without additional immunosuppressive agents has not been well investigated. In this study, 50 patients with lupus podocytopathy were included and received glucocorticoid alone (glucocorticoid monotherapy) or glucocorticoid plus additional immunosuppressive agents (combination therapy) for their induction or maintenance treatment regimens. The treatment response and relapse rate in the two groups were respectively analyzed. We found that the induction treatment with glucocorticoid monotherapy and combination therapy led to remission in 47 patients (94.0%) at 12 weeks treatment, with complete remission (CR) occurring in 38 patients (76.0%). The CR rate compared between glucocorticoid monotherapy and combination therapy showed no difference (76.7% vs 75.0%, p = 0.9), the median time to CR was four weeks (range: 2.0-6.0 weeks) in glucocorticoid monotherapy and 8.0 weeks (range: 3.7-12.0 weeks) in combination therapy (p = 0.076). Twenty-seven of 47 patients (57.4%) relapsed during maintenance, the relapse rate was much higher in the glucocorticoid monotherapy group than in the combination therapy group (89.5% vs 35.7%, p < 0.001), regardless of the induction regimens being glucocorticoid monotherapy or combination therapy. No patient developed end stage renal disease or died during follow-up for 6-125 months (median 62 months). In conclusion, the remission of lupus podocytopathy could be induced by glucocorticoid monotherapy or glucocorticoid plus other immunosuppressive agents, while the remission should be maintained by the combination regimen.

Mycophenolate in refractory and relapsing lupus nephritis

BACKGROUND

Mycophenolate (MF) is effective as induction and maintenance treatment in patients with lupus nephritis (LN). This study evaluates the efficacy and safety of MF in patients with refractory and relapsing LN.

METHODS

Data were retrospectively obtained for 85 patients (35 refractory and 50 relapsing) from 11 nephrology departments in Spain. The primary endpoints were the incidence and cumulative number of renal responses and relapses and their relationship with baseline clinical and analytical data. The secondary endpoint was the appearance of side effects.

RESULTS

The main clinical and analytical variables were similar both in refractory and relapsing LN. Most of the patients had received cyclophosphamide, and all of them switched to MF. 74 patients (87%) achieved a response (69% partial, 31% complete). Age at starting MF, gender, pathological classification, body mass index, blood pressure, baseline renal function, and proteinuria were not associated with achieving response. After stopping MF, 3 of 19 patients (15.7%) relapsed, all at 6 months of follow-up. No differences were found between clinical and analytical variables and number of relapses. Side effects were unremarkable, except for 1 patient, who died of thrombocytopenia and ovarian hemorrhage.

CONCLUSIONS

Switching to MF from other immunosuppressive treatments is effective and safe in refractory and relapsing LN.

The value of repeat kidney biopsy in quiescent Argentinian lupus nephritis patients

BACKGROUND

The duration of maintenance therapy after induction therapy for lupus nephritis has not been rigorously established. A common practice is to maintain immunosuppression for 1-2 years after complete remission, and longer for partial remission. The present work addresses whether a repeat kidney biopsy might be informative in deciding who should continue immunosuppression after complete or partial remission.

METHODS

The practice in a large Buenos Aires nephrology unit is to repeat a kidney biopsy before finalizing the decision to withdraw or continue immunosuppression. This work reports on a cohort of 25 Hispanic patients that had two or more kidney biopsies, the last occurring after at least 24 months of clinically quiescent disease.

RESULTS

Despite normalization of serum creatinine and reduction of proteinuria to <500 mg/d, 30% of patients still had significant activity at the last biopsy. Conversely, 60% of patients with ongoing proteinuria (500-1000 mg/d), or stable but abnormal serum creatinine, had no activity by biopsy. Univariate association analyses demonstrated that improvement in the activity index (AI) of the last biopsy was associated with choice of induction therapy (cyclophosphamide or mycophenolate), improvement in serum creatinine over the first six months of treatment, and improvement in complement component C4. By multivariate regression analyses, two AI prediction models emerged. Cyclophosphamide plus change in serum creatinine or cyclophosphamide plus change in C4 accounted for 50% of the improvement in AI.

CONCLUSION

These data suggest that a repeat biopsy may be useful in making the decision to withdraw or continue maintenance immunosuppression.