Membranous lupus nephritis

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

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

Long-term renal outcomes of patients with non-proliferative lupus nephritis

BACKGROUND/AIMS

Although non-proliferative lupus nephritis (LN) (class I, II or V) has been considered as a less severe type of LN, data on long-term renal prognosis are limited. We investigated the long-term outcomes and prognostic factors in non-proliferative LN.

METHODS

We retrospectively reviewed patients with systemic lupus erythematosus who were diagnosed with LN class I, II, V, or II + V by kidney biopsy from 1997 to 2021. A poor renal outcome was defined as an estimated glomerular filtration rate (eGFR) of < 60 mL/min/1.73 m2.

RESULTS

We included 71 patients with non-proliferative LN (class I = 4; class II = 17; class V = 48; class II+V = 2), and the overall rate of poor renal outcomes was 29.6% (21/71). The univariate analysis indicated that older age, low eGFR at 6 or 12 months, failure to reach complete remission at 6 months, and LN chronicity score > 4 or activity score > 6 were significantly associated with poor renal outcomes. The multivariate analysis revealed that low eGFR at 6 months (HR 0.971, 95% CI 0.949-0.991; p = 0.014) was significantly associated with poor renal outcomes.

CONCLUSION

Poor renal outcomes occurred in approximately 30% of patients with non-proliferative LN after long-term follow-up. More active management may be needed for non-proliferative LN, especially for patients with eGFR < 60 mL/ min/1.73 m2 at 6 months follow-up after LN diagnosis.

EXT1 and NCAM1-associated membranous lupus nephritis in a cohort of patients undergoing repeat kidney biopsies

BACKGROUND

Exostosin 1/2 (EXT1/2) and neural cell adhesion molecule 1 (NCAM1) associated membranous lupus nephritis (MLN) may represent distinct disease phenotypes with prognostic significance.

METHODS

We searched our archives for patients with systemic lupus erythematous (SLE) and at least two kidney biopsies demonstrating MLN. Each biopsy was stained for EXT1 and NCAM1 and scored as positive or negative. Histopathologic and clinical data were reviewed.

RESULTS

We identified 31 patients with a clinical diagnosis of SLE and at least two kidney biopsies with MLN. A total of 28 patients (90%) showed concordant staining for EXT1 and NCAM1 in both biopsies; 8 patients (26%) were EXT1 positive and NCAM1 negative, 18 patients (58%) were EXT1 negative and NCAM1 negative and 2 patients (7%) were EXT1 negative and NCAM1 positive. A total of three patients (10%) had discordant EXT1 staining between their first and last biopsies; two patients (7%) were EXT1 positive in their first biopsy and EXT1 negative in the last biopsy and one patient (3%) was EXT1 negative in his first biopsy and EXT1 positive in the last biopsy. Compared with the EXT1-negative cohort at the time of the first biopsy, the EXT1-positive cohort had a higher average estimated glomerular filtration rate (eGFR; 141 versus 108 mL/min/1.73 m2; P = 0.04), lower average percent global glomerulosclerosis (0.5 versus 12%; P = 0.05), lower average interstitial fibrosis and tubular atrophy (2.5 versus 11.7%; P = 0.06) and lower average total National Institutes of Health (NH) chronicity scores (0.75 versus 2.33; P = 0.05). On long-term follow-up, the rate of change in eGFR did not significantly differ between the two groups (P = 0.24). One EXT1-positive patient (12.5%) developed stage 4 chronic kidney disease (CKD) or end-stage kidney disease (ESKD) compared with four patients (20%) in the EXT-negative group and two of the three EXT1-discordant patients (P = 0.38).

CONCLUSIONS

We performed the largest retrospective repeat-biopsy study to evaluate EXT1 and NCAM1 autoantigens in MLN. Our data demonstrate that EXT1 positivity is associated with better kidney function at the time of diagnosis and raises the possibility that EXT1 status may change throughout the disease course of MLN.

Molecular signatures of intrarenal complement receptors C3AR1 and C5AR1 correlate with renal outcome in human lupus nephritis

OBJECTIVE

Lupus nephritis is one of the most common and serious complications of systemic lupus erythematosus (SLE). Lupus nephritis is a major cause of kidney failure in patients with SLE, attributed to increased morbidity and mortality. The in situ deposition of intrarenal immune complexes promotes the accumulation of inflammatory cells and causes kidney injury.

METHODS

We here extracted transcriptome array datasets for expression of complement molecules in human lupus nephritis. Furthermore, we performed gene set enrichment analysis to identify molecular signatures associated with follow-up kidney function in lupus nephritis.

RESULTS

Within the glomerular compartment, intrarenal mRNA expression levels of C3AR1 (p=0.0333) and C5AR1 (p=0.0167) correlated with treatment success reflected by kidney function recovery specifically in class III lupus nephritis, while no such association was observed in class II or class IV lupus nephritis. Interestingly, mRNA expression levels of either glomerular C3AR1 or C5AR1 resulted in identical gene set and signalling pathways enrichments in human lupus nephritis, including interferon signalling and signalling by interleukins. Direct comparison of C3AR1 and C5AR1 confirmed a strong association between glomerular mRNA expression levels of both complement receptors (r=0.8955, p<0.0001).

CONCLUSIONS

This study provides additional insights into signalling pathways associated with intrarenal synthesis of complement components in lupus nephritis that might be also affected by targeted therapy of the complement system. These results require confirmation but may contribute to a personalised treatment approach in distinct classes of human lupus nephritis.

Efficacy and safety of intravenous immunoglobulin in patients with lupus nephritis: A systematic review of the literature

INTRODUCTION AND OBJECTIVE

Intravenous immunoglobulin (IVIg) is an anti-inflammatory drug with an unclear role in the treatment of patients with lupus nephritis (LN). This systematic review evaluates the evidence for IVIg in the care of patients with LN.

METHODOLOGY

A systematic search was done in the PubMed, EMBASE, BVS and OVID databases - All EBM Reviews following the PRISMA methodology (registration in PROSPERO CRD42021236662). The variables were extracted: indications for use, dosage, partial or complete response, adverse reactions, initiation of renal replacement therapy, reduction of proteinuria, and mortality. The quality assessment was done with the "The Joanna Briggs Institute (JBI) Critical Appraisal tools for use in Systematic Reviews Checklist". In addition, synthesis reports were prepared through the Synthesis Without Meta-analysis - SWiM guide.

RESULTS

A total of 2328 articles were obtained (28 were considered for inclusion). When the studies were evaluated, IVIg therapy was found to be between 60% to 70% effective (except for patients with class V LN) with overall responses (complete + partial) even for patients who are refractory to first line treatment. Normalization (<0.5 g) of nephrotic proteinuria occurred in 24% of cases with infrequent adverse events and a mortality plus dialysis composite of 11.5% and 24.1% (most representative study).

CONCLUSION

In patients with LN refractory to conventional treatment or co-infection situations, the reported data seem to demonstrate effectiveness of IVIg therapy. There are few adverse reactions and caution is exercised when using it on patients with class V NL. However, given the lack of controlled studies with long-term follow-up, these data should be interpreted cautiously thus encouraging the development of high-quality RCTs.

Proteomic profiling of kidney samples in patients with pure membranous and proliferative lupus nephritis

Renal injury in lupus nephritis (LN) does not manifest as one uniform entity. The clinical presentation, management, and prognosis of membranous LN (MLN) differ from that of the proliferative LN (PLN). Differentiating the molecular mechanisms involved in MLN and PLN and discovering the reliable biomarkers for early diagnosis and target therapy are important. We compared the kidney protein expression patterns of 11 pure MLN and 12 pure PLN patients on formalin-fixed paraffin-embedded (FFPE) kidney tissues using label-free liquid chromatography-mass spectrometry (LC-MS) for quantitative proteomics analysis. FunRich software was used to identify proteins in differentially expressed pathways. Quantitative comparisons of differentially expressed proteins in each patient were further analyzed based on protein intensity levels determined by LC-MS. The protein-protein interaction (PPI) network of the differentially expressed genes (DEGs) was established through Search Tool for the Retrieval of Interacting Genes database (STRING) website, visualized by Cytoscape. A total of 5112 proteins were identified. In total, 12 significantly upregulated (fold change ≥2, p < 0.05) proteins were identified in the MLN group and 220 proteins (fold change ≥2, p < 0.05) were upregulated in the PLN group. Further analysis showed that the most significant upregulated pathway involved in MLN was histone deacetylase (HDAC) class I pathway, and the three most significant upregulated pathways in PLN were interferon signaling, interferon gamma signaling, and the immune system. Next, we selected sirtuin-2 (SIRT2) in MLN, and vascular cell adhesion protein 1 (VCAM1) and Bcl-xl in PLN for further mass spectrometry (MS) intensity and PPI analysis. SIRT2 expression was significantly increased in the MLN group compared with the PLN group, and VCAM1, Bcl-xl expression was significantly increased in the PLN group compared with the MLN group, based on MS intensity. These results may help to improve our understanding of the underlying molecular mechanisms of MLN and PLN and provide potential targets for the diagnosis and treatment of different subclasses of LN.

New Insights Into an Overlooked Entity: Long-Term Outcomes of Membranous Lupus Nephritis From a Single Institution Inception Cohort

Introduction

Pure membranous lupus nephritis (MLN) accounts for 10–20% of total cases of lupus nephritis and is generally associated with a better patient and renal survival compared to proliferative classes. Studies of MLN are limited by small sample size and heterogeneity of included populations since patients with pure MLN and those with mixed classes are usually examined together.

Aim of the Study

To describe clinical and laboratory characteristics of patients with pure MLN, therapeutic regimens, response to treatment, renal relapses, and their long-term renal survival and to define prognostic factors of remission and relapse.

Methods

We retrospectively studied an inception cohort of 27 patients with histologically proven pure MLN. Clinical, laboratory and therapeutical parameters were recorded at diagnosis, at different time points (3–6–9–12–18–24–36–72 months) during the course of the disease, at time of renal flare, and at last follow up visit.

Results

48.1% (13/27) of patients were treated with mycophenolic acid (MPA), 29.6% (8/27) with cyclophosphamide (CYC), and 3.7% (1/27) with cyclosporine (all in combination with corticosteroids). Five patients (18.5%) did not receive any immunosuppressive treatment. Mean duration of treatment was 4.7 ± 2.3 years. Median time to complete remission was 9 months (IQR = 7) and median time to partial remission was 4 months (IQR = 4). No clinical or laboratory parameter was found to be significantly associated with time to remission. Time to remission was not significantly affected by either of the two treatment regimens (CYC and MPA) (p = 0.43). Renal flare was observed in 6 (22%) of the 27 patients in a median time of 51 months (IQR = 63). Proteinuria >1 g/24 h at 1 year significantly correlated with risk of flare (OR 20, p = 0.02). After a median follow up period of 77 months, all patients had an eGFR > 60 ml/min/1.73 m² (mean eGFR 100 ± 32 ml/min/1.73 m²).

Conclusions

In a small cohort of patients with pure MLN, long-term renal survival was very good. With the limitation of the small sample size, we could not find any baseline clinical, biochemical or therapeutic factor that could predict time to remission. Proteinuria > 1 g/24 h at 1 year should be further examined in larger cohorts as a possible predictor of flare.

Lupus Membranous Nephropathy

Background

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

Methods

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

Results

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

Discussion

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

Outcomes of membranous and proliferative lupus nephritis - analysis of a single-centre cohort with more than 30 years of follow-up

Objectives

To compare membranous lupus nephritis (MLN) and proliferative lupus nephritis (PLN) with respect to survival, demographic, clinical and laboratory characteristics; and to investigate predictors of renal and patient survival.

Methods

Single-centre retrospective observational study. Patients with biopsy-proven PLN, MLN and mixed lupus nephritis were included. Groups were compared using appropriate statistical tests and survival was analysed through the Kaplan-Meier method. Cox regression analysis was performed to investigate predictors of renal and patient survival.

Results

A total of 187 patients with biopsy-proven lupus nephritis (135 with PLN, 38 with MLN and 14 with mixed LN) were followed for up to 42 years (median 12 years). There was a higher proportion of MLN amongst Afro-Caribbeans than amongst Caucasians (31% vs 15%, P = 0.010). Patients with MLN had significantly lower anti-dsDNA antibodies (P = 0.001) and higher C3 levels (P = 0.018) at diagnosis. Cumulative renal survival rates at 5, 10, 15 and 20 years were 91, 81, 75 and 66% for PLN and 100, 97, 92 and 84% for MLN, respectively (P = 0.028). Cumulative patient survival at 5, 10, 15 and 20 years was 94, 86, 80 and 76%, with no difference between PLN and MLN. Urinary protein-creatinine ratio above 42 mg/mmol and eGFR below 76 ml/min/1.73 m², one year after the diagnosis of LN, were the strongest predictors of progression to end-stage renal disease. eGFR below 77 ml/min/1.73 m², at one year, development of end-stage renal disease and Afro-Caribbean ethnicity were associated with higher mortality.

Conclusion

Patients with MLN and PLN differ significantly regarding serological profiles and renal survival, suggesting different pathogenesis. Renal function at year one predicts renal and patient survival.

Lupus nephritis: clinical presentations and outcomes in the 21st century

Lupus nephritis (LN) is a frequent and severe manifestation of SLE. Along the decades, the epidemiology of LN and its clinical presentation have been changing. However, even though retrospective cohort studies report a decreased mortality rate and an improvement in the disease prognosis, the percentage of patients progressing into end stage renal disease (ESRD) keeps steady despite the improvements in therapeutic strategies. Current in-use medications have been available for decades now, yet over the years, regimens for optimizing their efficacy and minimizing toxicity have been developed. Therapeutic research is now moving towards the direction of precision medicine and several new drugs, targeting selectively different pathogenetic pathways, are currently under evaluation with promising results. In this review, we address the main changes and persistent unmet needs in LN management throughout the past decades, with a focus on prognosis and upcoming treatments.

Secondary Membranous Nephropathy. A Narrative Review

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

Clinical presentation and outcomes of childhood-onset membranous lupus nephritis

BACKGROUND

Best practices for managing childhood-onset membranous lupus nephritis (MLN) are not yet established. Most studies involve primarily or exclusively adult cohorts or pediatric cohorts with combinations of pure or mixed membranous and proliferative nephritis.

METHODS

We performed a single-center cohort study of consecutively diagnosed children with pure MLN from 1990 and 2016. Patients received care in Houston, Texas, one of the most diverse metropolitan areas in North America. Renal outcomes were obtained using consensus definitions from the Childhood Arthritis and Rheumatology Research Alliance (CARRA). Logistic regression was used to detect predictors of complete renal response.

RESULTS

A total of 56 children with MLN were identified (82% females, 44% black, 35% Hispanic) with a median follow-up time of 4.1 years. The mean age of MLN onset was 13.7 ± 3.4 years. On initial presentation 69% had nephrotic syndrome and 11% had acute kidney injury. Glucocorticoids were prescribed in 96% of patients and anti-malarials in 88%. Mycophenolate mofetil was the most common non-steroid immunosuppressive agent (69%), followed by rituximab (25%), cyclophosphamide (18%), and azathioprine (9%). Renin-angiotensin aldosterone system blocking agents were prescribed in 78% of patients. Of 37 patients with ≥2 years of follow-up, 74% achieved complete renal response at 24 months. No predictor variable of complete renal response was identified in this small cohort. Renal flares occurred in 48% of patients (86% proteinuric, 14% nephritic). On subsequent renal biopsy, 13% patients had developed proliferative nephritis.

CONCLUSIONS

This single-center cohort of childhood-onset MLN showed favorable outcomes. Utilizing pediatric renal outcomes definitions, we found that response rates were high, as were rates of renal flare.

Value of immunohistochemical expression of podocalyxin in active lupus nephritis

Podocalyxin is an electronegative sialoglycoprotein that prevents the podocyte foot process from collapsing. The aim of this study was to detect an association between the glomerular immunohistochemical (IHC) expression of podocalyxin and the degree of podocyte effacement detected by electron microscopy, and to evaluate the role of podocalyxin IHC expression as a novel marker for disease activity in lupus nephritis (LN).

METHODS

Thirty-two renal biopsies of active lupus nephritis patients were studied. Clinical assessment by the systemic lupus activity measure (SLAM-R) score and laboratory data were included [serum creatinine, 24-h urinary protein, antinuclear antibodies (ANA), anti-double-strand DNA antibodies (anti-dsDNA), C3 and C4]. Light (L/M) and electron microscopic (E/M) examination was conducted. Podocyte loss was evaluated by immunohistochemistry with monoclonal anti-podocalyxin antibodies by means of a semiquantitative score that was graded from 0 to 4+ according to the percentage of glomerular involvement.

RESULTS

22 cases (68.8%) with LN class IV, 6 (18.8%) with class III and 4 (12.5%) with class V. The mean age was (25.41±10.13) years. There was a significant negative correlation between IHC podocalyxin score and LN class, and NIH activity parameters such as leukocyte infiltration, endocapillary proliferation, fibrinoid necrosis and cellular crescent and disease activity index but not chronicity index. There was a highly significant negative correlation between IHC podocalyxin and podocyte effacement by E/M (rs=-0.903, P=0.000), and E/M immune deposits (r=-0.53, P=0.001), and a significant association with degree of proteinuria, ANA and SLAM score (P<0.05).

CONCLUSIONS

Podocyte loss indicated by podocalyxin immunohistochemical expression reflects the degree of activity and severity of LN and the degree of podocyte effacement by E/M.

Presentation and outcome of paediatric membranous non-proliferative lupus nephritis

BACKGROUND

Studies of paediatric patients with membranous lupus nephritis (MLN) have yielded variable results, mostly due to the inclusion of mixed, i.e. proliferative nephritis. The aim of this study was to describe clinical and laboratory findings at the diagnosis of paediatric non-proliferative MLN, report the outcome and identify predictors of remission.

METHODS

A single-center cohort study of consecutive children diagnosed with non-proliferative MLN was performed. Clinical and laboratory measures and treatment regimens were obtained in prospective standardized assessments. Renal outcome was measured by renal parameters and steroid requirement. Predictors for remission and time to remission were determined.

RESULTS

A total of 30 children were identified with a median follow-up time 4.1 years. Of 21 patients followed for more than 2 years, 19 (90 %) achieved clinical remission, and 16 (76 %) achieved a state of maintained clinical remission on low-dose prednisone. Three patients developed proliferative nephritis on subsequent renal biopsy. Lower albumin at the time of biopsy was correlated with a lower rate of remission and longer time to remission.

CONCLUSIONS

Among our paediatric patient cohort the outcome of non-proliferative MLN in systemic lupus erythematosus was good. The majority of patients did not require aggressive immunosuppressive treatment to reach a stable disease state on low-dose steroid treatment.

Immunoadsorption: a new strategy to induce remission in membranous lupus nephritis

We report the case of an 11-year-old previously healthy girl who presented for microscopic hematuria and nephrotic proteinuria with normal renal function, which persisted after 6 months of steroids, angiotensin-converting enzyme inhibitors (ACEi)/angiotensin receptor blockers, hydroxychloroquine, mycophenolic acid and a low-salt diet. A serum investigation suggested lupus nephritis and a renal biopsy, performed 2 weeks after the first proteinuria detection, revealed membranous lupus nephritis. We decided to perform ten sessions of daily immunoadsorption. Proteinuria decreased significantly over these ten sessions from 8 to 0.12 g/l. After the tenth immunoadsorption session, the patient received the first rituximab (RTX) infusion leading to complete B-cell depletion. The patient was maintained on ACEi associated with mycophenolic acid and hydroxychloroquine. Three RTX reinjections were performed when CD19-positive cells reappeared in peripheral blood. Despite complete B-cell recovery and positive anti-dsDNA-Ab, the patient remained in complete remission 18 months after the initial diagnosis with negative proteinuria and a normal renal function.

Podocyte involvement in lupus nephritis based on the 2003 ISN/RPS system: a large cohort study from a single centre

OBJECTIVE

The podocyte lesion in LN is still an intriguing controversy. We assess the associations between podocyte lesions and clinico-pathological features in a large cohort of LN patients.

METHODS

The clinico-pathological data of 202 patients with renal biopsy-proven LN were retrospectively studied. The degree of podocyte lesions was assessed morphologically and its correlations with clinico-pathological parameters were further analysed.

RESULTS

The podocyte foot processes of most LN patients significantly effaced, reflected by the median foot process width (FPW) of 1397.39 nm, and 13 patients met the histological criteria of lupus podocytopathy. The FPW was correlated with proteinuria (r = 0.509, P < 0.001) and the cut-off value of FPW, >1240 nm, could differentiate nephrotic proteinuria from non-nephrotic proteinuria with sensitivity 81.5% and specificity 62.7%. The FPW varied significantly with different types of LN, and the patients with combined LN presented with the most severe lesions. The complete remission rate was significantly higher and the long-term renal outcome was better in the group with calcineurin inhibitors than that with other regimens in patients with FPW >1240 nm.

CONCLUSION

Podocyte damage was common in LN. Pure lupus podocytopathy might act as an extreme form of lupus podocyte lesion, and more patients might present with severe podocyte effacement concealed in different types of LN, which needs further investigation.

Identification of urinary metabolites that distinguish membranous lupus nephritis from proliferative lupus nephritis and focal segmental glomerulosclerosis

Introduction

Systemic lupus erythematosus (SLE or lupus) is a chronic autoimmune disease, and kidney involvement with SLE, a.k.a. lupus nephritis (LN), is a frequent and severe complication of SLE that increases patient morbidity and mortality. About 50% of patients with SLE encounter renal abnormalities which, if left untreated, can lead to end-stage renal disease. Kidney biopsy is considered the criterion standard for diagnosis and staging of LN using the International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification, which was developed to help predict renal outcomes and assist with medical decision-making. However, kidney biopsy-based classification of LN is highly invasive and impractical for real-time monitoring of LN status. Here, nuclear magnetic resonance (NMR) spectroscopy-based metabolic profiling was used to identify urinary metabolites that discriminated between proliferative and pure membranous LN as defined by the ISN/RPS classification, and between LN and primary focal segmental glomerulosclerosis (FSGS).

Methods

Metabolic profiling was conducted using urine samples of patients with proliferative LN without membranous features (Class III/IV; n = 7) or pure membranous LN (Class V; n = 7). Patients with primary FSGS and proteinuria (n = 10) served as disease controls. For each patient, demographic information and clinical data was obtained and a random urine sample collected to measure NMR spectra. Data and sample collection for patients with LN occurred around the time of kidney biopsy. Metabolic profiling analysis was done by visual inspection and principal component analysis.

Results

Urinary citrate levels were 8-fold lower in Class V LN compared to Class III/IV patients, who had normal levels of urinary citrate (P < 0.05). Class III/IV LN patients had > 10-fold lower levels of urinary taurine compared to Class V patients, who had mostly normal levels (P < 0.01). Class V LN patients had normal urinary hippurate levels compared to FSGS patients, who completely lacked urinary hippurate (P < 0.001).

Conclusions

This pilot study indicated differences in urinary metabolites between proliferative LN and pure membranous LN patients, and between LN and FSGS patients. If confirmed in larger studies, these urine metabolites may serve as biomarkers to help discriminate between different classes of LN, and between LN and FSGS.

Mycophenolate mofetil in the treatment of lupus nephritis

Lupus nephritis is a complication of systemic lupus erythematosus, which has significant morbidity and mortality. The accepted standard of treatment for severe lupus nephritis is cyclophosphamide for induction of remission. This has significant adverse effects including severe infection and amenorrhea. In addition, although cyclophosphamide induces remission, long-term mortality does not seem to be altered. Mycophenolate mofetil (MMF) is an immunosuppressive agent originally used in solid organ transplantation, which has been compared with cyclophosphamide in trials for lupus nephritis. Randomized trials with MMF have been relatively small, although pooled data seem to suggest that it is at least as effective as cyclophosphamide in inducing remission. In addition, MMF has also been associated with a reduced risk of infection and amenorrhea, although this finding is not universal. MMF appears to be associated with more diarrhea compared with cyclophosphamide. MMF is likely to be a useful treatment for lupus nephritis, although available trial data are limited due to the small size of previous studies. A large trial (the Aspreva Lupus Management Study) is currently underway to attempt to establish the place of MMF in treatment of lupus nephritis.

Lupus nephritis mimicking pyelonephritis in pregnancy

BACKGROUND

Systemic lupus erythematosis (SLE) is a multisystemic autoimmune connective tissue disorder that presents with a wide range of clinical manifestations including renal involvement. Routine prenatal care includes assessment of renal function.

CASE

A 29-year-old nullipara presented at 17 weeks with fever, vomiting, and costovertebral angle tenderness 1 week after being treated for a presumed urinary tract infection. On presentation, new-onset hypertension was noted. Inpatient evaluation established a diagnosis of SLE with lupus nephritis. The pregnancy ended with intrauterine fetal demise.

CONCLUSION

SLE is a disease with complex and protean clinical manifestations. It should appear on the differential when more common disease processes are ruled out. Routine prenatal care can detect otherwise silent and undiagnosed renal disease, and with early intervention improve prognosis.

Mycophenolate mofetil and intravenous cyclophosphamide are similar as induction therapy for class V lupus nephritis

Class V lupus nephritis (LN) occurs in one-fifth of biopsy-proven cases of systemic lupus erythematosus. To study the effectiveness of treatments in this group of patients, we pooled analysis of two large randomized controlled multicenter trials of patients with diverse ethnic and racial background who had pure class V disease. These patients received mycophenolate mofetil (MMF) or intravenous cyclophosphamide (IVC) as induction therapy for 24 weeks, with percentage change in proteinuria and serum creatinine as end points. Weighted mean differences, pooled odds ratios, and confidence intervals were calculated by using a random-effects model. A total of 84 patients with class V disease were divided into equal groups, each group had comparable entry variables but one received MMF and one received IVC. Within these groups, 33 patients on MMF and 32 patients on IVC completed 24 weeks of treatment. There were no differences between the groups in mean values for the measured end points. Similarly, no difference was found regarding the number of patients who did not complete the study or who died. In patients with nephrotic syndrome, no difference was noted between those treated with MMF and IVC regarding partial remission or change in urine protein. Hence we found that the response to MMF as induction treatment of patients with class V LN appears to be no different from that to IVC.

Membranous lupus nephritis in Chinese children--a case series and review of the literature

We retrospectively reviewed the cases of 13 lupus nephritis children with pure membranous glomerulonephritis (MGN; Group A) and ten children with mixed proliferative and membranous nephritis (Group B). The children were identified through a territory-wide survey of patients between 1990 and 2003. All were ethnic Chinese. Age at diagnosis ranged from 3.7 to 18.6 years (Group A) and from 9.6 to 22.1 years (Group B). Female-to-male ratios were 12:1 (Group A) and 9:1 (Group B). Group A patients were more often nephrotic than Group B patients (11/13 vs. 5/10, p = 0.17). The glomerular filtration rate (GFR) at presentation was normal in all but two patients (one from each group). For induction, Group B patients consistently received prednisolone and cyclophosphamide; in contrast, the cytotoxic regimens in Group A patients varied from cyclophosphamide (five patients), mycophenolate mofetil (two patients), azathiorpine plus cyclosporine (one patient), and azathioprine alone (one patient). After a median follow-up of 7.6-7.8 years, one Group A patient had died of fulminant lupus. One survivor in Group B had a GFR < 90 ml/min per 1.73 m(2). Proteinuria persisted in five Group A patients and two Group B patients. In conclusion, Group B patients had good prognosis in terms of survival and proteinuria control. The only death occurred in Group A, and five of the 12 survivors in this group had persistent proteinuria. Further studies are needed to define the best treatment for pure lupus MGN.

Clinical approach to lupus nephritis: recent advances

Kidney involvement is common in systemic lupus erythematosus (SLE). Its clinical presentations are highly variable, ranging from mild asymptomatic proteinuria and/or hematuria to rapidly progressive uremia. Histological evidence of lupus nephritis is present in most patients with SLE, even when they do not yet have clinical manifestations. Current classification ISN/RPS 2003 (International Society of Nephrology/Renal Pathology Society) of lupus nephritis was promoted by a widely perceived need to re-examine existing classification, provide clearer distinctions between the histological classes, and improve diagnostic reproducibility and interobserver agreement. Lupus nephritis is a serious disease whose prognosis can usually be improved dramatically by treatment, but treatment is potentially toxic, prolonged, and complex. Current treatment regimens combine corticosteroids with cyclophosphamide, azathioprine or ciclosporin; mycophenolate mofetil has received much recent attention as a potentially immune suppressive agent and less aggressive immunosuppressive regimens can be prescribed. SLE patients should be regular followed to detect early kidney involvement.

Rituximab in severe lupus nephritis: early B-cell depletion affects long-term renal outcome

BACKGROUND AND OBJECTIVES

Standard treatment for lupus nephritis, including corticosteroids and cyclophosphamide, is efficient but is still associated with refractory or relapsing disease, or severe deleterious effects. Rituximab, a monoclonal chimeric anti-B cell antibody, is increasingly used in patients with lupus nephritis, but reported series were small and had a short follow-up.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The authors analyzed clinical and histologic data of 20 patients who were treated with rituximab for lupus nephritis and followed up for at least 12 mo.

RESULTS

Nineteen women and one man received rituximab as induction treatment for an active class IV (15 cases) or class V (5 cases) lupus nephritis. Rituximab was given for lupus nephritis refractory to standard treatment (12 cases), for relapsing disease (6 cases), or as first-line treatment (2 cases). Three patients received cyclophosphamide concomitantly with rituximab. Ten received new injections of rituximab as maintenance therapy. Side effects included mainly five infections and four moderate neutropenias. After a median follow-up of 22 mo, complete or partial renal remission was obtained in 12 patients (60%). Lupus nephritis relapsed in one patient, who responded to a new course of rituximab. The achievement of B cell depletion 1 mo after rituximab, which negatively correlated with black ethnicity and hypoalbuminemia, was strongly associated with renal response. Rapidly progressive glomerulonephritis did not respond to rituximab.

CONCLUSION

Rituximab is an interesting therapeutic option in relapsing or refractory lupus nephritis when early B cell depletion is obtained.

Efficacy and safety of TNF-blocker therapy in systemic lupus erythematosus

BACKGROUND

There is still unmet medical need in the therapy of severe organ manifestations of patients with systemic lupus erythematosus (SLE). Therapeutic agents targeting pro-inflammatory cytokines may be an interesting option.

OBJECTIVE

To review available data on the efficacy and safety of tumour necrosis factor (TNF) blockade in SLE.

METHODS

A review of the literature was conducted.

RESULTS/CONCLUSIONS

Open-label experience suggests that TNF blockade is effective in SLE patients with arthritis, nephritis and skin disease. In particular, nephritis may remain in long-term remission after just four infusions of infliximab administered. Despite the induction of lupus-specific autoantibodies, short-term therapy with infliximab in combination with azathioprine appears feasible and relatively safe. The data call for controlled clinical trials, at least one of which has been initiated.

Tacrolimus for the treatment of systemic lupus erythematosus with pure class V nephritis

OBJECTIVES

The treatment of pure membranous (class V) lupus nephropathy remains unsatisfactory. We studied the efficacy and safety of tacrolimus in the treatment of membranous nephritis secondary to SLE.

METHODS

We recruited 18 consecutive SLE patients (tacrolimus group) with recently confirmed biopsy-proven class V lupus nephritis. They were treated with a tailing dose of oral prednisolone and tacrolimus 0.1-0.2 mg/kg/day for 6 months, followed by maintenance prednisolone and AZA. The rate of resolution of proteinuria and SLEDAI were compared with 19 historical controls treated with oral cyclophosphamide or AZA (control group). All patients were followed for 12 months.

RESULTS

Baseline clinical characteristics were comparable between the groups. For the tacrolimus group, the complete and partial remission rates were 27.8 and 50.0%, respectively at 12 weeks; for the control group, they were 15.8 and 47.4%, respectively (overall chi-square test, P = 0.5). However, tacrolimus group had faster resolution of proteinuria than the control group by the general linear model with repeated measures (P = 0.032). At 12 weeks, proteinuria was reduced by 76.2 +/- 17.0% for the tacrolimus group and 47.1 +/- 51.1% for the control group (P = 0.028). Serial change in renal function and SLEDAI score did not differ between the groups. During the study period, four patients of the tacrolimus group, and 11 of the control group, developed lupus flare (P = 0.027). There was no serious adverse effect in the tacrolimus group.

CONCLUSIONS

A 6-month course of tacrolimus is a safe and effective treatment of pure class V (membranous) lupus nephritis. As compared with conventional cytotoxic treatment, tacrolimus possibly results in a faster resolution of proteinuria, and a lower risk of lupus flare within 1 yr. The long-term effect and optimal regimen of tacrolimus require further study.

Pharmacotherapy of lupus nephritis: time for a consensus?

BACKGROUND

The optimal therapy for lupus nephritis has been the subject of considerable debate.

OBJECTIVE

To provide evidence- and expert-based recommendations.

METHODS

To review the literature and the European League Against Rheumatism recommendations.

RESULTS

Risk stratification based on histological, demographical, clinical and laboratory characteristics allows the identification of patients at high risk for loss of renal function, and thus more likely to benefit from more aggressive therapy. Achieving remission within the first months of treatment, irrespective of the agent used, correlates with good long-term renal outcomes; maintenance of remission can be achieved with less toxic therapies. Aggressive management of atherosclerosis risk factors and renoprotective therapy for those patients with chronic renal disease improve long-term survival and prognosis.

Mycophenolate mofetil as induction and maintenance therapy for lupus nephritis: rationale and protocol for the randomized, controlled Aspreva Lupus Management Study (ALMS)

The Phase III Aspreva Lupus Management Study (ALMS) will investigate mycophenolate mofetil (MMF) therapy for lupus nephritis (LN). Eligibility criteria include: 12-75 years of age; diagnosis of systemic lupus erythematosus according to revised American College of Rheumatology criteria; and biopsy-demonstrated LN (Class III-V). Randomized patients will receive open-label induction therapy with MMF or cyclophosphamide in combination with corticosteroids for 24 weeks. The primary efficacy endpoint is treatment response [decreased proteinuria and stabilized (within 25% of baseline) or improved serum creatinine level]. Patients achieving response or complete remission (normalization of all parameters) will be rerandomized to double-blind, placebo-controlled maintenance treatment with MMF or azathioprine, both plus corticosteroids. The maintenance phase primary endpoint is time to treatment failure. To detect a 15% rate improvement in the MMF group compared with cyclophosphamide, and to provide 90% power, a total of 358 patients will be required for the induction phase. On the basis of a projected 278 rerandomized patients, the maintenance phase will have 90% power to detect a difference between treatment groups assuming azathioprine and MMF three-year failure rates of 59.5% and 40.7%, respectively. Aspreva Lupus Management Study may provide invaluable comparative data on the efficacy and safety of MMF as LN induction and maintenance therapy.

Long-term outcome of Chinese patients with membranous lupus nephropathy

A retrospective analysis of the long-term outcome of patients with membranous lupus nephropathy (MLN) was conducted. One hundred Chinese patients, 90 females and 10 males with a mean age of 32 ± 9 years, with systemic lupus erythematosus and biopsy-proven MLN (ISN/RPS2003 classification criteria) were enrolled in this study. The patient and renal survivals were estimated by the Kaplan—Meier method and the risk factors associated with end-stage renal failure (ESRF) were assessed by the Cox proportional hazards regression analysis. The mean follow-up of all patients was 77.6 ± 56 months. During follow-up, two patients died. Patient survival at 5 and 10 years was 98%. Renal survival at 5 and 10 years was 96.1% and 92.7%, respectively. Severe tubular-intersticial lesion (HR 66.514), nephrotic range proteinuria (HR 19.159) and refractoriness to treatments (HR 9.834) were independent risk factors for developing ESRF. Three of the six patients with ESRF had severe tubular-interstitial lesions on initial biopsy. Twenty-one patients underwent a repeat biopsy after 33months' (median time) follow-up, eight (38.1%) of these (class V superimposed class IV in 5, class V superimposed class III in 2 and class VI in 1) had transformed and three (37.5%) of them progressed to ESRF. Complications included infection (13%), thrombosis (3%), avascular necrosis (3%), diabetes mellitus (4%) and skin cancer (1%). The rate of patient and renal survival was high in this group of patients with MLN.

[Lupus membranous nephropathy]

The systemic lupus erythematosus associated renal hystopathological complexity and its clinical translation, are still a diagnostic challenge with therapeutical implications which, however, include new options in the last few years within the immunosupression compass. The new insights elicited by research work attempt to give some light on renal biopsy performance, its relationship with the arrogated clinical spectrum, its prognosis and on the lupus nephropathy new treatments currently under ongoing clinical trials, some of them showing encouraging results. The lupus membranous nephropathy, recognized as an anatomopathological entity more than 4 decades ago, means a specific pattern in the whole renal lupus histologycal range and, in many aspects, an etiopathogenic enigma.

Upregulated expression of cardiac ankyrin-repeated protein in renal podocytes is associated with proteinuria severity in lupus nephritis

Cardiac ankyrin-repeated protein (CARP) was originally identified as a protein specifically expressed in cardiomyocytes, but has recently been found to be upregulated in some muscle diseases including muscular dystrophy and myopathy, suggesting that CARP may be induced in some pathologic conditions. In this study, we immunohistochemically analyzed 69 renal biopsy samples from patients with glomerular diseases and 2 individuals with normal kidney. We found that CARP was expressed in renal podocytes at a high level in 10 of 13 cases of crescentic glomerulonephritis, 7 of 19 cases of diabetic nephropathy, and 12 of 20 cases of lupus nephritis, although it was not expressed in endocapillary glomerulonephritis, minimal change disease, thin basement membrane disease, membranous glomerulonephritis, and normal kidney. Interestingly, in lupus nephritis, CARP expression tended to be induced in cases exhibiting nephrotic syndrome, but less so in cases without nephrotic syndrome, suggesting that CARP expression is correlated with the severity of proteinuria. Furthermore, we found that CARP was not expressed in membranous glomerulonephritis but evidently expressed in most cases of membranous lupus nephritis. Although membranous glomerulonephritis and membranous lupus nephritis are sometimes morphologically indistinguishable, it is suggested that their pathologic mechanisms differ. Therefore, we propose that examination of CARP expression is useful for precise differential diagnosis of membranous glomerulonephritis and membranous lupus nephritis.

Retrospective analysis of patients with lupus nephritis: data from a large clinical immunological center in Hungary

The aim of this study was to review the development, histological type and outcome of 117 patients with lupus nephritis managed and followed by the Division of Clinical Immunology, 3rd Department of Internal Medicine, University of Debrecen, Debrecen, Hungary. The method used was a retrospective study in 117 patients with lupus nephritis followed between 1974 and 2004. The average occurrence of lupus nephritis was 3 (women) and 4.4 (men) years later after the diagnosis of systemic lupus erythematosus, 43 (46.2%) patients had class IV lupus nephritis. The initial therapy was intravenous cyclophosphamide treatment for 6 months in 37 (31.6%) patients. End-stage renal disease had developed in nine (7.6%) patients. The 5-year survival rate was 99.1%. Despite the well-known and proved risk factors like hypertension, high serum creatinine, renal failure at onset or membranous glomerulonephritis, the outcome of the disease in our patient population was more favourable than one would expect according to the data available in the literature. The authors would like to draw attention to the importance of systematic care of patients with systemic lupus erythematosus, which may lead to a better clinical outcome.

Optimum therapeutic approaches for lupus nephritis: what therapy and for whom?

The optimum therapy for patients with lupus nephritis is a hotly debated topic. Prospective randomized studies in patients with proliferative lupus nephritis have established the superiority of cyclophosphamide to azathioprine, both of which are used in combination with corticosteroids. Although high-dose, intermittent administration of cyclophosphamide (pulse therapy) has significantly reduced the toxicity associated with this drug, premature ovarian failure and infections remain considerable problems. Short-term to intermediate-term, randomized controlled trials have shown that mycophenolate mofetil is a good option for the induction and maintenance of remission in lupus nephritis patients. Additional longer-term trials involving more patients and stricter outcomes based on renal function are needed, however, before claims that mycophenolate mofetil is superior to cyclophosphamide can be substantiated. Until such data are available, physicians caring for patients with lupus nephritis can use mycophenolate mofetil as induction or maintenance therapy for selected patients under close observation. Small noncontrolled trials with short-term follow-up suggest that up to 50% of patients who are refractory to cyclophosphamide might have a clinically significant response to rituximab, a monoclonal antibody directed against B cells.

Prognosis of lupus membranous nephropathy in children

The occurrence of membranous nephropathy in pediatric series of systemic lupus erythematosus has been reported only rarely, probably due to a very low frequency. One hundred fifty-four children who were seen in 100 French pediatric centers between January 2002 and April 2005 were included. Fifteen (12 girls and three boys) out of the 81 (18.5 %) children with renal involvement presented histological features of membranous nephropathy. Their ages ranged from six to 15 years old (mean=11.3) at the age of SLE diagnosis and 8/15 children were of African origin. Isolated membranous nephropathy was observed in nine patients, of whom five patients displayed a complete recovery following immunosuppressive treatment. Associated proliferative lesions were observed on the first kidney specimen in two patients and in a further renal biopsy in four other patients, leading to a less favorable course of lupus nephropathy.

Mycophenolate mofetil is effective in reducing lupus glomerulonephritis proteinuria

Mycophenolate mofetil (MMF) significantly reduces proteinuria in experimental model of human membranous nephropathy (Heymann nephritis). Twenty consecutive SLE patients with persistent isolated severe proteinuria and/or proteinuric flare were studied for 18 months of MMF therapy. All of them presented stable renal function and 12 had biopsy proven membranous glomerulonephritis (WHO class V). The starting daily dose for MMF was 1.5 g to a maximum of 3 g. Patients were divided into: partial response, >or=50% decrease of baseline proteinuria; complete response, normal proteinuria levels (less than 0.3 g/24 h); flare, increase of at least 50% of the mean baseline proteinuria. All 20 SLE patients (100%) presented a 50% reduction of baseline proteinuria which was achieved in 8.2+/-3.3 months of MMF therapy, at a mean daily dose of 2.3+/-0.5 g. A significant decrease in 24-h protein excretion was observed compared to entry (3.47+/-1.26 vs. 1.33+/-0.67 g, P<0.0001) as well as a correspondent increase of serum albumin (3.2+/-0.4 vs. 3.7+/-0.4 mg/dl, P=0.02) and reduction of prednisone dose (33.7+/-20.0 to 18.6+/-14.1 mg/day, P=0.01). Complete response was observed in 11 SLE patients (55%) in 12.2+/-3.0 months of therapy with a significant decrease in proteinuria (P<0.0001), prednisone dose (P<0.0001) and an increase of serum albumin (P=0.003). Interestingly, initial proteinuria or serum albumin levels did not identify patients with complete response and those with partial response at the end of the study (P=0.543 and 0.657, respectively). Our pilot prospective study suggests that MMF appears to be effective in reducing severe persistent proteinuria in lupus glomerulonephritis, even in patients unresponsive to other immunosuppressive treatments.