Silent nephritis in systemic lupus erythematosus

[Risk factors and prognosis of pediatric silent lupus nephritis with class Ⅲ to Ⅴ]

OBJECTIVES

To study the risk factors and prognostic characteristics of pediatric silent lupus nephritis (SLN) with class Ⅲ to V.

METHODS

A retrospective study was conducted to collect clinical data from 30 children diagnosed with SLN at the Department of Pediatrics, Second Xiangya Hospital, Central South University, from May 2007 to April 2023. Based on renal pathological classification, the patients were divided into a class Ⅱ group (12 cases) and a class Ⅲ to Ⅴ group (18 cases). The risk factors for the occurrence of class Ⅲ to Ⅴ SLN were analyzed, and the prognostic characteristics were summarized.

RESULTS

Among the 30 SLN patients, the median follow-up time was 61.50 months. There were no statistically significant differences in the proportions of patients who discontinued glucocorticoids or achieved low disease activity status, nor in the annual decline rate of estimated glomerular filtration rate (eGFR) between the class Ⅱ and class Ⅲ to V groups (P>0.05). However, three patients in the class Ⅱ group progressed to stage 1 chronic kidney disease (CKD), while eight patients in the class III to V group reached stage 1 CKD, and four patients reached stage 2 CKD. Among the 26 female SLN patients, serum complement C3 levels in the class III to V group were lower than those in the class Ⅱ group (P<0.05). Serum C3 levels in SLN patients, as well as in female SLN patients, were negatively correlated with the fluorescence intensity of IgA, IgG, and C3 immune complexes in the kidneys (P<0.05). Additionally, serum C3 levels in female SLN patients were negatively correlated with the renal pathological activity index (P<0.05). Binary logistic regression analysis indicated that being female and having low serum complement C3 levels were risk factors for the occurrence of class Ⅲ to V SLN in children (P<0.05).

CONCLUSIONS

Class Ⅲ to V SLN is not uncommon among SLN children, and there remains a risk of long-term renal function progression. Being female and having low serum complement C3 levels are identified as risk factors for class Ⅲ to V SLN in children.

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.

Role of [68Ga]-pentixafor positron emission tomography/computed tomography imaging in assessing disease activity in patients with lupus nephritis: A pilot study

OBJECTIVE

The primary objective of our study was to evaluate renal uptake of 68Ga-pentixafor in patients with lupus nephritis. Eighteen patients who satisfied the inclusion criteria were included in our study.

METHODS

The study participants were patients with histopathologically confirmed lupus nephritis who were referred to our department for 68Ga-pentixafor PET/CT scan. We studied the renal images in these patients for uptake patterns based on purely visual as well as semi-quantitative parameters. The visual parameters included uptake relative to the spleen and liver. Semi-quantitative analysis involved the uptake as given by SUVmax. These parameters were correlated with the patients' biochemical as well as histological parameters. Kendall's tau-b test was used to look for an association between renal uptake by visual assessment and histopathological findings. Mean SUVmax values were compared by using the Mann-Whitney U test and a p value < .05 was considered to be statistically significant.

RESULTS

No significant association between the mean renal SUVmax of the bilateral kidneys in pentixafor PET and histopathological class was observed. We did not observe any heterogeneity in uptake patterns that could be attributed to the disease process in our patients.

CONCLUSION

68Ga-pentixafor PET is not a suitable imaging modality for assessment of disease activity in lupus nephritis patients. There is a void in non-invasive testing for patients with this chronic and often disabling condition which calls for further research in this area.

Does kidney biopsy in pediatric lupus patients "complement" the management and outcomes of silent lupus nephritis? Lessons learned from a pediatric cohort

BACKGROUND

Silent lupus nephritis (SLN) is systemic lupus erythematosus (SLE) without clinical and laboratory features of kidney involvement but with biopsy-proven nephritis. This study aims to describe and compare the baseline characteristics and outcomes of pediatric SLN with overt LN (OLN) and to identify associated risk factors and biochemical markers.

METHODS

In this retrospective, observational study, multivariate logistic regression and receiver operating characteristic (ROC) analyses studied age, sex, race, serum complements, anti-double-stranded-DNA antibody, anti-Smith antibody, eGFR, and proliferative nephritis.

RESULTS

In our cohort of 69 patients, 47 were OLN, and 22 were SLN. OLN (OR = 4.9, p = 0.03) and non-African Americans (AA) (OR = 13.0, p < 0.01) had higher odds, and increasing C3 and C4 were associated with lower odds of proliferative nephritis (OR 0.95 and 0.65 per one unit increase in C3 and C4, respectively, p < 0.01). They demonstrated a good discriminative ability to detect proliferative nephritis as assessed by the area under the ROC curve (C3 = 0.78, C4 = 0.78). C3 and C4 in proliferative SLN and OLN were comparable and significantly lower than their non-proliferative counterparts. No association was observed between age, sex, anti-double-stranded-DNA antibody, anti-Smith antibody, eGFR, and proliferative nephritis. Proliferative SLN and OLN patients received similar treatments. Adverse events were identified in the proliferative OLN only.

CONCLUSIONS

Lower complement levels are associated with proliferative lesions in pediatric LN-both SLN and OLN. The non-AA population had higher odds of having proliferative nephritis than the AA. Prospective, randomized, long-term follow-up of proliferative SLN patients is needed to ascertain the beneficial effect of early diagnosis and treatment. A higher resolution version of the Graphical abstract is available as Supplementary information.

Apoptosis in lupus nephritis patients: a study of Bcl-2 to assess glomerular and tubular damage

Background

Systemic lupus erythematosus (SLE) is an immune-mediated disease, due to exposure of self-antigens, through impairment of apoptosis and failure of lymphocytic tolerance. Impaired regulation of the pro- and anti-apoptotic gene products which coordinate programmed cell death may result in autoreactive B and T cells and autoimmunity. Genetically engineered mice that over-express the anti-apoptotic molecule Bcl-2, B cell lymphoma 2 (Bcl2) in B-lymphocytes advance a lupus-like illness. Lupus nephritis (LN) is one of the most serious manifestations of this autoimmune disorder. Glomerulonephritis (GN) is caused by either impaired regulation of apoptosis and/or clearance of apoptotic cells leading to a T cell-mediated autoimmune reaction with initiation of pathological immune complex deposits.

Objective

To evaluate the correlation between Bcl2 glomerular and tubular expression and pathological findings and laboratory data in different types of SLE GN.

Results

Compared to the control group, patients with lupus nephritis have significantly higher glomerular, interstitial and tubular expression level (P value < 0.001). BCL2 expression was positively correlated with serum anti-ds-DNA, urine 24-h protein and with the chronicity index. All LN patients had significant glomerular, interstitial and tubular deposits of BCL2, P value < 0.001, P value 0.004, and P value 0.03, respectively.

Conclusion

The intrinsic pathway of apoptosis interferes not only with the pathogenesis of lupus glomerulonephritis but also interferes with the pathogenesis of tubulointerstitial lupus nephritis. tubulointerstitial lesions may not only be a result of glomerular injury but also a significant factor in lupus nephritis.

Levels of Proteinuria and Renal Pathology in Systemic Lupus Erythematosus Patients

According to the current guidelines, renal biopsies are performed in systemic lupus erythematosus (SLE) patients for proteinuria of 0.5 g/24 h or higher. Renal pathology may be present in patients with lower-level proteinuria (<0.5 g/24 h). We aimed to review the renal histopathology in SLE patients, with lower levels of proteinuria. In this retrospective study, we retrieved SLE patients' data, including 24-h urinary protein excretion and renal histopathology results. We compared various parameters in different lupus nephritis (LN) classes and in different levels of proteinuria (urinary protein <0.5 g, 0.5 to <1 g, and ≥1 g per 24 h). Out of 476 patients, 274 (57.6%) had proteinuria of <0.5 g, 44 (9.2%) had 0.5 to <1 g, and 158 (33.2%) had ≥1 g per 24 h. SLE patients with proteinuria of <0.5 g/24 h were found to have LN, including the proliferative classes. Of the 299 LN cases confirmed by a renal biopsy, low-level proteinuria (<0.5 g) was found in 39.8% of all LN patients, in 50% of patients with Class III LN, 33.3% of those with Class IV LN, 31.4% of those with Class V LN, and 41.4% of those with other LN classes (II/V, III/V, and IV/V). Overall, 35.9% (87/242) of patients with the proliferative LN classes (III, IV, V, II/V, III/V and IV/V) had low-level proteinuria of <0.5 g/24 h. SLE patients with low-level proteinuria had significant renal pathology. Our study suggests there is a need to perform renal biopsies at lower levels of proteinuria.

Delivery of AntagomiR-7 through polymer nanoparticles for assisting B Cell to alleviate systemic lupus erythematosus

An autoimmune condition known as systemic lupus erythematosus (SLE) is characterized by B cell hyperresponsiveness and persistent generation of pathogenic autoantibodies that cause damage to various organs and tissues. The treatments available today are either ineffective or have adverse effects. The dysregulation of B cell activation is crucial for the emergence of SLE. MiR-7 explicitly targeted PTEN mRNA in B cells. Treatment with antagomiR-7 reduced B cell hyperresponsiveness and prevented the onset of lupus. As a result, inhibiting miR-7 may be used therapeutically to treat SLE. We developed a SA (sialic acid)-poly (D, L-lactide-co-glycolide) (SA-PLGA) nano delivery system to deliver antagomiR-7 into splenic B cells since the stability and targeted delivery of miRNA remain significant challenges in vivo. Results show that SA-PLGA nanoparticles (SA-PLGA@antagomiR-7) loaded with antagomiR-7 display good biocompatibility and shield antagomiR-7 from degradation, extending the miRNA's duration in circulation in vivo. Additionally, in MRL/Ipr lupus mice, SA-PLGA@antagomiR-7 is successfully delivered to the splenic B cells and preferentially enriched in the diseased spleen in MRL/Ipr lupus mice. The SA-PLGA@antagomiR-7 NPs therapy effectively decreases immunological abnormalities, normalizes splenic B cell subtypes, and suppresses B cell activation. The antagomiR-7 NPs exhibit excellent therapeutic efficiency and high biosafety collectively, which may result in a more effective treatment for SLE.

Lupus nephritis: new progress in diagnosis and treatment

Systemic lupus erythematosus (SLE) is a chronic multifactorial autoimmune disease that affects many organs, including the kidney. Lupus nephritis (LN) is a common manifestation characterized by heterogeneous clinical and histopathological findings, and often associates with poor prognosis. The diagnosis and treatment of LN is challenging, depending largely on renal biopsy, and there is no reliable non-invasive LN biomarker. Up to now, the complete remission rate of LN is only 20%∼30% after receiving six months of standard treatment, which is far from satisfactory. Moreover, adverse reactions to immunosuppressants, especially glucocorticoids, further compromise the prognosis of LN. Biological reagents targetting autoimmune responses and inflammatory pathways, bring hope to the treatment of intractable lupus. The European Renal Association-European Dialysis and Transplant Association (EULAR/ERA-EDTA) and KDIGO (Kidney Disease: Improving Global Outcomes) have been working on and launched the recommendations for the management of LN. In this review, we update our knowledge in the pathogenesis, diagnosis, and management of LN and prospect for the future potential targets in the management of LN.

Retrospective review of the clinical and laboratory data in silent lupus nephritis

PURPOSE

To determine the ratio of renal disease necessitating immunosuppressive treatment in lupus patients who are clinically asymptomatic by means of renal disease. It was also examined whether silent lupus nephritis is associated with any of the non-renal clinical findings.

METHODS

All kidney biopsies performed in lupus patients between 1990 and 2009 at the Rheumatology Department of Ege University Faculty of Medicine were retrospectively screened. Among the 258 kidney biopsies screened, 54 had no clinical renal findings but had active disease together with anti-dsDNA positivity and/or hypocomplementemia. Patients were classified into two groups who require and do not require immunosuppressive therapy according to their final pathological results at biopsy. The frequency of serious renal involvement in the sample was calculated. Then subgroups were compared with each other in terms of the clinical and laboratory features using Statistical Package for Social Sciences version 13 software.

RESULTS

Thirteen of the 54 patients (24%) had severe renal involvement requiring immunosuppressant therapy. When the groups were compared to each other, it was found that serositis and hematologic involvement were significantly more frequent in patients who needed immunosuppressive treatment (42.9% versus 10.0%; p = 0.003 and 64.3% versus 37.5; p = 0.039).

CONCLUSION

Even in the absence of clinical renal manifestations, active patients at high risk of renal disease such as hypocomplementemia, anti-ds DNA positivity may have severe renal disease requiring immunosuppressive treatment. Thus, renal biopsy indications in lupus patients should better be revaluated.

Elevation of serum fibroblast growth factor 23 level in a pediatric patient with lupus nephritis

Fibroblast growth factor 23 (FGF-23), a hormone mainly secreted by osteocytes and osteoblasts, regulates phosphate and vitamin D levels. However, the in vivo significance of FGF-23 is not fully elucidated. This case report describes a 12-year-old girl with systemic lupus erythematosus (SLE), lupus nephritis, and an elevated serum FGF-23 level. The patient was treated with active vitamin D and oral sodium phosphate medications to manage low serum phosphate levels (2.2 mg/dL). Magnetic resonance imaging (MRI) revealed a high-intensity area in the left femur, but somatostatin receptor scintigraphy images did not indicate tumor-induced osteomalacia. SLE treatment using mycophenolate mofetil (1500 mg/day) was initiated, and serum complements levels increased as FGF-23 level increased. Serum FGF-23 level gradually decreased as urinary protein levels decreased after treatment with steroids; however, there was no change in the high-intensity area on MRI. Recent studies have reported that serum FGF-23 level is associated with iron deficiency and inflammation; yet, the mechanism related to these associations is not fully elucidated. The findings from this case suggest that elevated serum FGF-23 levels noted in our patient were related to silent lupus nephritis and lupus nephritis activity.

Kidney outcomes for children with lupus nephritis

Systemic lupus erythematosus is a rare lifelong multi-systemic autoimmune condition. Juvenile-onset SLE (JSLE) is recognized to have a more active disease course when compared with adult-onset disease and patients have a worse long-term survival. Kidney involvement occurs in over 50% of children and treatment decisions are guided by the histological classification. Several international groups have produced treatment protocols that rely on an intense period of immunosuppression to halt the acute kidney inflammatory process, followed by maintenance therapy with close observation for disease improvement and prompt evaluation of disease flares. A reduced glomerular filtration rate at presentation is predictive of later stage chronic kidney disease (CKD) in multivariate analysis. Kidney remission remains suboptimal with only 40-60% of patients achieving complete remission. Kidney flares are seen in over a third of patients. The rate of CKD 5 is reported to be up to 15% and the presence of lupus nephritis (LN) has an established link with an associated increase in mortality. In established kidney failure, transplantation seems to be the optimal kidney replacement modality for this group of patients, ideally after a period of disease quiescence. Modified outcome measures in clinical trials have demonstrated that biologic agents can be effective in this disease. Current biologic agents under investigation include obinutuzimab, belimumab, atacicept, anifrolumab, tocilizumab, eculizumab, dapirolizumab, and abatacept. Future research should focus on discovering early disease biomarkers, including surrogates for later cardiovascular disease, and evaluating biological agents as adjuncts to improve the rates of complete remission and subsequently influence the kidney outcome. The aim of this review article is to summarize the current kidney outcomes for this disease with a view to identifying key areas that may help to reduce the risk of long-term CKD.

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.

The Emerging Role of Renal Tubular Epithelial Cells in the Immunological Pathophysiology of Lupus Nephritis

Systemic lupus erythematosus (SLE) is a systemic, autoimmune disease that can involve virtually any organ of the body. Lupus nephritis (LN), the clinical manifestation of this disease in the kidney, is one of the most common and severe outcomes of SLE. Although a key pathological hallmark of LN is glomerular inflammation and damage, tubulointerstitial lesions have been recognized as an important component in the pathology of LN. Renal tubular epithelial cells are resident cells in the tubulointerstitium that have been shown to play crucial roles in various acute and chronic kidney diseases. In this context, recent progress has been made in examining the functional role of tubular epithelial cells in LN pathogenesis. This review summarizes recent advances in our understanding of renal tubular epithelial cells in LN, the potential role of tubular epithelial cells as biomarkers in the diagnosis, prognosis, and treatment of LN, and the future therapeutic potential of targeting the tubulointerstitium for the treatment of patients with LN.

Low-Level Proteinuria in Systemic Lupus Erythematosus

Introduction

In patients with systemic lupus erythematosus (SLE) without concurrent active urinary sediment or unexplained acute kidney injury (AKI), current guidelines recommend performing a kidney biopsy in those with at least 500 mg/24-hour (European League Against Rheumatism/European Renal Association-European Dialysis and Transplant Association [EULAR/ERA-EDTA]) or 1000 mg/24-hour (American College of Rheumatology [ACR]) proteinuria. To evaluate the relevance of these indications, we studied histopathologic findings in patients with SLE with proteinuria below these cutoffs.

Methods

We retrospectively reviewed the clinical, laboratory and histological characteristics of patients with SLE with <1000 mg/24-hour proteinuria (or mg/g urinary protein-to-creatinine ratio [UPCR]) who underwent their first kidney biopsy between 2003 and 2018.

Results

We identified 87 patients with SLE with proteinuria less than 1000 mg/24-hour (or mg/g UPCR); 52 of 87 (60%) with isolated proteinuria, that is, without AKI or active urinary sediment (hematuria). Histologic evidence of lupus nephritis (LN) was present in 40 of 52 (76%). Of the 40 patients with LN, 12 had class I or II, 14 had class III or IV, 8 had class V, 6 had a combined proliferative and membranous LN. Non-lupus diagnoses included focal segmental glomerulosclerosis, acute interstitial nephritis, and others. Patient’s age, low C3, low C4, and positivity for anti-double-stranded DNA (anti-dsDNA) antibodies predicted the histological diagnosis of LN on univariate logistic regression; however, a multivariate model including these parameters as independent covariates failed to predict LN.

Conclusions

Patients with SLE with low-level proteinuria may have significant lupus- or non–lupus-related kidney disease with management implications. There was a significant burden of severe forms of LN. The presence of LN was not predicted by laboratory abnormalities. Based on our findings, we suggest current guidelines be revised to expand kidney biopsy indications to include isolated proteinuria of any grade.

MicroRNA-125a-Loaded Polymeric Nanoparticles Alleviate Systemic Lupus Erythematosus by Restoring Effector/Regulatory T Cells Balance

Systemic lupus erythematosus (SLE), a common lethal autoimmune disease, is characterized by effector/regulatory T cells imbalance. Current therapies are either inefficient or have severe side effects. MicroRNA-125a (miR-125a) can stabilize Treg-mediated self-tolerance by targeting effector programs, but it is significantly downregulated in peripheral T cells of patients with SLE. Therefore, overexpression of miR-125a may have therapeutic potential to treat SLE. Considering the stability and targeted delivery of miRNA remains a major challenge in vivo, we constructed a monomethoxy (polyethylene glycol)-poly(d,l-lactide-co-glycolide)-poly(l-lysine) (mPEG-PLGA-PLL) nanodelivery system to deliver miR-125a into splenic T cells. Results demonstrate that miR-125a-loaded mPEG-PLGA-PLL (PEAL_miR-125a) nanoparticles (NPs) exhibit good biocompatibility and protect miR-125a from degradation, thereby prolonging the circulatory time of miRNA in vivo. In addition, PEAL_miR-125a NPs are preferentially enriched in a pathological spleen and efficiently deliver miR-125a into the splenic T cells in SLE mice models. The PEAL_miR-125a NPs treatment significantly alleviates SLE disease progression by reversing the imbalance of effector/regulatory T cells. Collectively, the PEAL_miR-125a NPs show excellent therapeutic efficacy and safety, which may provide an effective treatment for SLE.

Interleukin-34 as a marker for subclinical proliferative lupus nephritis

Background

Lupus nephritis (LN) is an ominous manifestation of systemic lupus erythematosus (SLE). Clinical renal affection is present in about 70% of lupus patients, and more patients have histological evidence of renal involvement without clinical manifestations. This study aimed to investigate the potential role of serum interleukin-34 (IL-34) as an early marker for the detection of silent LN.

Methods

Thirty-three lupus patients with silent LN (group I), 37 patients with clinical LN (group II) and 20 controls were included. The SLE Disease Activity Index (SLEDAI), IL-34, anti-dsDNA antibodies and renal biopsy were assessed in all patients.

Results

Serum IL-34 levels were significantly higher in all lupus patients compared to healthy controls ( p < 0.001) and showed a significant positive correlation with SLEDAI score. SLE patients with positive anti-dsDNA antibodies had more active disease according to SLEDAI and higher levels of IL-34 than those with negative anti-dsDNA antibodies. In both studied groups, serum IL-34 levels were significantly higher in patients with proliferative LN (class III and class IV) than those with non-proliferative lupus (class II and class V) and controls. Yet, in both groups, IL-34 was not useful in differentiating active from chronic renal affection.

Conclusion

In lupus patients with insignificant proteinuria, serum levels of IL-34 distinguished the different histological classes of subclinical LN. Serum IL-34 may be used as a surrogate marker for early renal affection in silent LN, especially the proliferative type.

Deep Phenotyping of Urinary Leukocytes by Mass Cytometry Reveals a Leukocyte Signature for Early and Non-Invasive Prediction of Response to Treatment in Active Lupus Nephritis

Non-invasive biomarkers are necessary for diagnosis and monitoring disease activity in lupus nephritis (LN) to circumvent risks and limitations of renal biopsies. To identify new non-invasive cellular biomarkers in the urine sediment of LN patients, which may reflect kidney inflammation and can be used to predict treatment outcome, we performed in-depth urinary immune cell profiling by mass cytometry. We established a mass cytometric workflow to comparatively analyze the cellular composition of urine and peripheral blood (PB) in 13 patients with systemic lupus erythematosus (SLE) with active, biopsy-proven proliferative LN. Clinical and laboratory data were collected at the time of sampling and 6 months after induction of therapy in order to evaluate the clinical response of each patient. Six patients with different acute inflammatory renal diseases were included as comparison group. Leukocyte phenotypes and composition differed significantly between urine and paired PB samples. In urine, neutrophils and monocytes/macrophages were identified as the most prominent cell populations comprising together about 30%–83% of nucleated cells, while T and B lymphocytes, eosinophils, and natural killer (NK) cells were detectable at frequencies of <10% each. The majority of urinary T cells showed phenotypical characteristics of activated effector memory T cells (EM) as indicated by the co-expression of CD38 and CD69 – a phenotype that was not detectable in PB. Kidney inflammation was also reflected by tissue-imprinted macrophages, which phenotypically differed from PB monocytes by an increased expression of HLA-DR and CD11c. The presence of activated urinary T cells and macrophages could be used for differential diagnosis of proliferative LN forms and other renal pathologies. Most interestingly, the amount of EM in the urine sediment could be used as a biomarker to stratify LN patients in terms of response to induction therapy. Deep immunophenotypic profiling of urinary cells in LN allowed us to identify a signature of activated T cells and macrophages, which appear to reflect leukocytic infiltrates in the kidney. This explorative study has not only confirmed but also extended the knowledge about urinary cells as a future non-invasive biomarker platform for diagnosis and precision medicine in inflammatory renal diseases.

Urine TWEAK level as a biomarker for early response to treatment in active lupus nephritis: a prospective multicentre study

Background

TNF-like weak inducer of apoptosis (TWEAK) is a proinflammatory molecule that plays a key role in active inflammation of lupus nephritis (LN). Urine TWEAK (uTWEAK) levels were found to be associated with renal disease activity among patients with LN. Here, we determined whether serial measurements of uTWEAK during induction therapy could predict treatment response or not.

Methods

Spot urine samples were collected from patients with biopsy-proven active LN at time of flare, and 3 and 6 months after flare to assess the uTWEAK levels. All patients received standard immunosuppressive therapy and treatment response was evaluated at 6 months. The performance of uTWEAK as a predictor for treatment response was compared with clinically used biomarkers for patients with LN.

Results

Among 110 patients with LN, there were 29% complete responders (CR), 34% partial responders (PR) and 37% non-responders (NR). On average, uTWEAK level was consistently low in CR, trended down by 3 months in PR and persistently elevated in NR. uTWEAK levels at month 3 were able to predict complete response at month 6 (OR adjusted for age, sex and creatinine=0.34 [95% CI 0.15 to 0.80], the area under the receiver operating characteristic curve [ROC-AUC]=0.68, p=0.02). The optimal threshold for uTWEAK level at month 3 was 0.46 pg/mgCr, discriminating complete response with 70% sensitivity and 63% specificity. Combining uTWEAK and urine protein at month 3 improved predictive performance for complete response at 6 months (ROC-AUC 0.83, p<0.001).

Conclusions

In addition to urine protein, uTWEAK level at 3 months after flare can improve the accuracy in predicting complete response at 6 months of induction therapy.

The potential diagnostic utility of coexpression of Ki-67 and P53 in the renal biopsy in pediatric lupus nephritis

Background

The proliferative activity as well as apoptosis has been suggested to play a role in the pathogenesis of lupus nephritis (LN). The aim of the study was to investigate the coexpression of Ki-67-triggered marked proliferation and P53-induced apoptosis in renal biopsy of childhood lupus nephritis (cLN) and to compare the coexpression of proliferative and apoptotic indices between different subgroups and clinicopathologic patterns of renal disease.

Methods

Renal biopsy specimens of 33 children with lupus nephritis (LN) and 10 healthy subjects were retrospectively evaluated. The type of LN and activity and chronicity indices were determined. Ki-67 and P53 immunostaining were performed. The coexpression of Ki-67 and P53 was compared among different subgroups of LN and correlated with disease activity index, serum creatinine, proteinuria, anticardiolipin antibodies, and complement levels. Histopathological examination of LN was classified based on the International Society of Nephrology/Renal Pathology. Histological LN activity was measured by the National Institutes of Health activity index (NIH-AI).

Results

In comparison with the healthy control group, the coexpression of Ki-67and P53 was greater in cLN (particularly in classes II, III, and IV) than in normal renal tissue. The coexpression of Ki-67and P53 shows a positive correlation with subclasses II, III, and IV of LN (P<0.02) and LN activity index (P<0.03). Moreover, the positive correlation was found between the coexpression of Ki-67 and P53 with erythrocyte sedimentation rate (P<0.02), D-dimer (P<0.03), serum creatinine (P<0.03), proteinuria (P<0.04), and anticardiolipin antibodies (P<0.05) significantly. Unexpectedly, adverse correlation between the coexpression of Ki-67 and P53 with serum C3 (P<0.02) and C4 complement (P<0.03) was significant.

Conclusion

Our data showed that the coexpression of Ki-67-induced marked proliferation and P53-induced apoptosis in proliferative and active phases of cLN could reflect a valuable marker for treatment and remission in cLN patients before reaching the end stage of renal disease.

Lupus nephritis: low urinary DNase I levels reflect loss of renal DNase I and may be utilized as a biomarker of disease progression

Renal DNase I is lost in advanced stages of lupus nephritis. Here, we determined if loss of renal DNase I reflects a concurrent loss of urinary DNase I, and whether absence of urinary DNase I predicts disease progression. Mouse and human DNase I protein and DNase I endonuclease activity levels were determined by western blot, gel, and radial activity assays at different stages of the murine and human forms of the disease. Cellular localization of DNase I was analyzed by immunohistochemistry, immunofluorescence, confocal microscopy, and immunoelectron microscopy. We further compared DNase I levels in human native and transplanted kidneys to determine if the disease depended on autologous renal genes, or whether the nephritic process proceeded also in transplanted kidneys. The data indicate that reduced renal DNase I expression level relates to serious progression of lupus nephritis in murine, human native, and transplanted kidneys. Notably, silencing of renal DNase I correlated with loss of DNase I endonuclease activity in the urine samples. Thus, urinary DNase I levels may therefore be used as a marker of lupus nephritis disease progression and reduce the need for renal biopsies.

Mechanisms of Tissue Injury in Lupus Nephritis

Disease heterogeneity remains a major challenge for the understanding of systemic lupus erythematosus (SLE). Recent work has revealed the important role of nonimmune factors in the development of end-organ damage involvement, shifting the current paradigm that views SLE as a disease inflicted by a disturbed immune system on passive target organs. Here, we discuss the pathogenesis of lupus nephritis in a comprehensive manner, by incorporating the role that target organs play by withstanding and modulating the local inflammatory response. Moreover, we consider the effects that genetic variants exert on immune and nonimmune cells in order to shape the phenotype of the disease in each affected individual.

A Systematic Review and Meta-analysis of Prevalence of Biopsy-Proven Lupus Nephritis

Objectives

This study aims to conduct a meta-analysis to clarify the epidemiologic characteristics of biopsy-proven lupus nephritis (BPLN), including those relating to its prevalence and prognosis.

Patients and methods

A literature search for relevant studies was conducted in the electronic databases of PubMed, Google Scholar, Embase, and Cochrane trial register. The following search terms were used for original articles published between January 1982 and April 2016: "lupus nephritis" or systemic lupus erythematosus ('SLE') or 'systemic lupus erythematous' and "pathology" or 'epidemiology' or prevalence or incidence. Pooled estimates with 95% confidence intervals were calculated.

Results

Nineteen studies were included (mean age of SLE patients at renal biopsy: ~30 years). Of total BPLN patients, 85% were females. BPLN developed in 29% of SLE patients, and accounted for 60% of secondary glomerular diseases in renal biopsy databases. BPLN prevalence among SLE patients was higher in Saudi Arabia compared with pooled Europe/USA data (43% vs 26%, p<0.05). Pooled BPLN prevalence among secondary glomerular diseases patients was higher in Asian/Latin American countries than in Europe (63% vs 34%, p<0.05). Overall five-, 10- and 20-year survival rates of BPLN patients were 94%, 86%, and 71%, respectively, which were higher than those before 1995 (84%, 72%, and 52%, respectively) and lower than those after 1995 (96%, 89%, and 80%, respectively) (all p<0.05). Class IV nephritis, present in 40% of BPLN patients, was a risk factor for renal failure that contributed to poor prognosis.

Conclusion

Lupus nephritis is a common complication of young female patients with SLE, and the most prevalent etiology of secondary glomerular diseases. Attention should be paid to class IV nephritis due to its high frequency and association with poor prognosis.

Modular transcriptional repertoire analyses identify a blood neutrophil signature as a candidate biomarker for lupus nephritis

Objective

LN is a severe complication of SLE. Non-invasive biomarkers are needed for identifying patients at risk of a renal flare, for differentiating proliferative from non-proliferative forms and for assessing prognoses for LN.

Methods

We assessed the link between blood transcriptional signatures and LN using blood samples from patients with biopsy-proven LN, extra-renal SLE flares or quiescent SLE. Healthy controls, and control patients with glomerular diseases or bacterial sepsis were included. Modular repertoire analyses from microarray data were confirmed by PCR.

Results

A modular neutrophil signature (upregulation of module M5.15) was present in 65% of SLE patients and was strongly associated with LN. M5.15 activity was stronger in LN than in extra-renal flares (88 vs 17%). M5.15 was neither correlated to IFN modules, nor to SLEDAI or anti-dsDNA antibodies, but moderately to CS dose. M5.15 activity was associated with severity of LN, was stronger when proliferative, and decreased in patients responding to treatment. M5.15 activation was not caused by higher CS dose because it correlated only moderately to neutrophil count and was also observed among quiescent patients. Among quiescent patients, those with a past history of LN had higher M5.15 activity (50 vs 8%). M5.15 activation was present in patients with bacterial sepsis or ANCA-associated vasculitis, but not in patients with other glomerular diseases. Overall, M5.15 activation was associated with past, present or future flares of LN.

Conclusion

Modular neutrophil signature could be a biomarker for stratifying LN risk and for monitoring its response to treatment.

Trial registration

ClinicalTrials.gov, http://clinicaltrials.gov , NCT00920114.

Urinary Albumin Levels are Independently Associated with Renal Lesion Severity in Patients with Lupus Nephritis and Little or No Proteinuria

Background

Systemic lupus erythematosus (SLE) leads to renal lesions, which may be clinically silent in patients with little or no proteinuria. Early detection of these lesions may improve prognosis, but early markers are controversial. This study aimed to determine renal marker proteins associated with renal lesion severity in patients with lupus nephropathy (LN) and little or no proteinuria.

Material/Methods

Patients with LN and little or no proteinuria (<0.5 g/24 hours) (n=187) that underwent kidney biopsy were grouped according to: low severity (Class I or II; n=116) versus high severity (Class III, IV, or V; n=71). Disease status was determined according to the SLE disease activity index (SLEDAI). Renal marker proteins (serum β2-macroglobulin, urinary β2-macroglobulin, albumin, IgG, and α1-macroglobulin) were measured using radioimmunoassay.

Results

Compared with the low severity group, patients in the high severity group had higher urinary albumin (11.60±8.94 versus 7.08±10.07 μg/mL, p=0.008) and urinary IgG (13.21±9.35 versus 8.74±8.90 μg/mL, p=0.007) levels. Multivariate conditional logistic regression analysis showed that urinary albumin (odds ratio (OR)=1.417, 95% confidence interval (95% CI): 1.145–1.895, p=0.001) and SLEDAI (OR=2.004, 95% CI: 1.264–3.178, p=0.003) were independently associated with severe renal lesions in these patients. Using an optimal cutoff point of urinary albumin of 7.53 μg/mL resulted in 67% sensitivity and 82% specificity for the detection of high severity renal lesions.

Conclusions

Urinary albumin levels and SLEDAI were independently associated with histological severity of renal lesions in patients with LN and little or no proteinuria. These parameters could be used to help select patients for renal biopsy.

Further description of early clinically silent lupus nephritis

Thirty silent lupus nephritis (SLN) patients were compared to 16 individuals bearing overt lupus nephritis (OLN). Results included: years of systemic lupus erythematosus (SLE) diagnosis were significantly earlier (4.6 ± 2.8 years) in SLN than in OLN (7.18 ± 3.61) ( P < 0.05). Neurological compromise, hypertension, normocitic anemia and lymphopenia were significantly prevalent in OLN than in SLN ( P < 0.05). Beside normal urinary sediment and renal function tests, the SLN group showed a moderate increase of both activity (AI) and chronicity (CI) renal pathology index when compared to highly increased AI and CI in OLN ( P < 0.05). Seventy percent of SLN patients were ISN/RPS Classes I (6.6%) and II (63.3%) while 81% of OLN cases were Classes III, IV (37.5%) and V. IgG, IgA, IgM, λchain, C3 and fibrinogen immune deposits were found in 90% or over in both SLN and OLN individuals while in 60% or over, both groups also showed K chain, C1q and C4 deposits. While prevalence of ANA, anti-dsDNA and anti-C1q antibodies were similar in both groups, anti-histone, anti-RNP, CIC and CH50 serum levels were significantly different in OLN versus SLN ( P < 0.05). We strongly suggest that indeed SLN is the earliest stage in the natural history of lupus nephritis.

Spot urine protein/creatinine ratio is unreliable estimate of 24 h proteinuria in lupus nephritis when the histological scores of activity index are higher

OBJECTIVES

The aim of this study was to evaluate the correlation and agreement of spot urine protein/creatinine (P/C) ratio with 24 h proteinuria in patients with lupus nephritis (LN) under different scores of activity index (AI).

METHODS

In total, 90 pairs of 24 h urine and spot urine samples from 90 patients with biopsy-proven LN were analyzed. The correlation and agreement between the two sample types were assessed by Pearson correlation and intra-class correlation coefficient (ICC) using mixed model for repeated measurements, respectively.

RESULTS AND CONCLUSIONS

Overall, 24 h proteinuria correlated strongly with the spot urine P/C ratio (r = 0.671, p < 0.001) with a good agreement (ICC = 0.656, 95% confidence interval (CI): 0.52-0.76). Subgroup analyses revealed that the correlation remained high in all groups (r = 0.825, p < 0.001; r = 0.567, p = 0.001; r = 0.686, p = 0.020), the agreement in group A (low AI) was good (ICC = 0.824, 95% CI: 0.70-0.89), but in group B (middle AI) and group C (high AI), the agreements were weak (ICC = 0.503, 95% CI: 0.19-0.72; ICC = 0.532, 95% CI: 0.06-0.84). Our work suggests that over the range of a higher AI, however, correlation was present but agreement was poor.

Urine VCAM-1 as a marker of renal pathology activity index in lupus nephritis

Introduction

Although renal pathology is highly predictive of the disease course in lupus nephritis, it cannot be performed serially because of its invasive nature and associated morbidity. The goal of this study is to investigate whether urinary levels of CXC ligand 16 (CXCL16), monocyte chemotactic protein-1 (MCP-1) or vascular cell adhesion molecule-1 (VCAM-1) in patients with lupus nephritis are predictive of particular features of renal pathology in renal biopsies obtained on the day of urine procurement.

Methods

CXCL16, MCP-1, and VCAM-1 levels were measured in urine samples from 74 lupus nephritis patients and 13 healthy volunteers. Of the patients enrolled, 24 patients had a concomitant kidney biopsy performed at the time of urine collection. In addition, patients with other renal diatheses were also included as controls.

Results

All three molecules were elevated in the urine of systemic lupus erythematosus patients, although VCAM-1 (area under curve = 0.92) and MCP-1 (area under curve = 0.87) were best at distinguishing the systemic lupus erythematosus samples from the healthy controls, and were also most strongly associated with clinical disease severity and active renal disease. For patients in whom concurrent renal biopsies had also been performed, urine VCAM-1 exhibited the strongest association with the renal pathology activity index and glomerulonephritis class IV, although it correlated negatively with the chronicity index. Interestingly, urinary VCAM-1 was also elevated in anti-neutrophil cytoplasmic antibodies-associated glomerulonephritis, focal segmental glomerulosclerosis and membranous nephropathy but not in minimal-change disease.

Conclusion

Urinary VCAM-1 emerges as a reliable indicator of the activity:chronicity ratios that mark the underlying renal pathology in lupus nephritis. Since VCAM-1 is involved in the acute phase of inflammation when leukocytic infiltration is ongoing, longitudinal studies are warranted to establish whether tracking urine VCAM-1 levels may help monitor clinical and pathological disease activity over time.

A retrospective analysis of clinical presentation of lupus nephritis

INTRODUCTION

Lupus nephritis (LN) is an ominous complication of systemic lupus erythematosus, and the risk factors for the disease progression are not well characterized.

METHODS

In a retrospective study, the authors evaluated the mode of presentation and outcomes of 163 consecutive patients with biopsy-proven LN, who presented to the center between January 1999 and September 2008. Using stepwise logistic regression analysis, the authors assessed risk factors independently associated with response to treatment and to progression to end-stage renal disease (ESRD) in proliferative LN (PLN).

RESULTS

Ninety percent of the patients belonged to minority population. Among 122 patients with class III and IV LN (PLN), 76 patients received intravenous cyclophosphamide and 38 patients received mycophenolate for induction, whereas 34 patients received intravenous cyclophosphamide and 63 patients received mycophenolate for maintenance. Thirty-six (30%) patients with PLN progressed to ESRD, and 3 patients died over a mean follow-up of 37.5 months. In multivariate analysis, chronicity index (CI) (P = 0.0007) and hypertension (P = 0.042) positively correlated with progression to ESRD and death, and CI was associated with increased probability of nonresponse to treatment (P = 0.001). In addition, mycophenolate as maintenance agent was associated with increased likelihood of sustained complete remission and partial remission (P = 0.045).

CONCLUSIONS

In patients with LN, hypertension and a high CI are independent risk factors for progression to ESRD or death. Furthermore, a high CI is associated with poor response, and mycophenolate as a maintenance agent may improve the response to treatment.

Outcome and predictors of kidney disease progression in Puerto Ricans with systemic lupus erythematosus initially presenting with mild renal involvement

OBJECTIVES

The aims of this study were to determine the outcomes and predictors of renal disease progression in Puerto Ricans with systemic lupus erythematosus (SLE) initially presenting mild renal involvement.

METHODS

A retrospective cohort of 61 patients with SLE (per American College of Rheumatology classification) with mild renal involvement was studied. Mild renal disease was defined as glomerular filtration rate (GFR) of 90 mL/min or higher in the presence of proteinuria (>0.25 g/d, but <3.5 g/d), hematuria, and/or urinary cellular casts. Demographic parameters, clinical manifestations, serologic markers, comorbidities, pharmacologic treatments, disease activity, and damage accrual were determined at onset of renal disease. Factors associated with renal disease progression were evaluated using recurrent event survival analysis.

RESULTS

Of 61 patients, 55 (90.2%) were women. The mean (SD) age at renal onset was 29 (11.2) years, and the mean (SD) follow-up period was 5.1 (3.4) years. Thirty-eight patients had a decline in GFR. Thirty-two had a mild decline (GFR = 60-89 mL/min), 5 developed moderate to severe renal insufficiency (GFR = 15-59 mL/min), and 1 evolved to end-stage renal disease (GFR < 15 mL/min). In the Cox model, low C4 levels and proteinuria greater than 0.5 g/d were associated with an earlier decline in GFR.

CONCLUSIONS

Most Puerto Rican patients with SLE initially presenting with mild renal involvement had a decrease in GFR after an average of 5 years of kidney disease, although most had a mild dysfunction. Low C4 levels and proteinuria were predictors of an earlier decline in GFR. We emphasize that awareness of these factors may contribute to early identification of individuals at risk for renal deterioration.

Frequency of class III and IV nephritis in systemic lupus erythematosus without clinical renal involvement: an analysis of predictive measures

OBJECTIVE

To determine the frequency of International Society of Nephrology/Renal Pathology Society (ISN/RPS) class III or IV lupus nephritis in patients with systemic lupus erythematosus (SLE) without clinical renal involvement.

METHODS

We investigated the renal pathology of 195 patients with SLE, including 86 patients without clinical renal involvement.

RESULTS

Lupus nephritis other than class I was found in 58% of the patients without clinical renal involvement, and class III and IV nephritis was found in 15% of these patients. To reveal the predictive measures involved in class III or IV lupus nephritis, we explored the clinical measures in patients with SLE who did not have clinical renal involvement. Anti-dsDNA antibody titers were significantly higher (p = 0.0266) and C3 values were significantly lower (p = 0.0073) in patients with class III or IV lupus nephritis than in patients without class III or IV lupus nephritis. The sensitivity and specificity values were 77% and 73%, respectively, for cutoff levels of both 40 IU/ml for anti-dsDNA antibodies and 55 mg/dl for C3 (OR 8.8, p = 0.0011).

CONCLUSION

The frequency of nephritis, including ISN/RPS class III and IV, was unexpectedly high in SLE patients without clinical renal involvement. ISN/RPS class III or IV lupus nephritis could be hidden in patients with SLE who present both a high titer of anti-dsDNA antibody and a low concentration of C3, even when they have clinically normal urinary findings and renal function.

Major lupus organ involvement: severe lupus nephritis

Lupus nephritis is a common and severe complication of systemic lupus erythematosus. A number of patients have nephritis as a presenting feature that, in its severe form, can shortly lead to end-stage renal disease and/or death. Renal flare usually occurs a few years after the first episode and is remarkably predominant in the Asian population. Frequent monitoring for renal flare enhances early recognition and timely treatment. The mainstay therapy continues to be the prolonged use of cytotoxic/immunosuppressive drugs that have a number of undesirable effects, particularly ovarian failure and development of opportunistic infections. This review will focus on the pathogenesis and the unique genetic factors found in Asian patients with lupus nephritis. Here, we propose an appropriate management scheme for the treatment of lupus nephritis in Asian patients.

Deficiency of activating Fcγ-receptors reduces hepatic clearance and deposition of IC and increases CIC levels in mercury-induced autoimmunity

Background

Inorganic mercury (Hg) induces a T-cell dependent, systemic autoimmune condition (HgIA) where activating Fcγ-receptors (FcγRs) are important for the induction. In this study we examined the influence of activating FcγRs on circulating levels and organ localization of immune complexes (IC) in HgIA.

Methods and Principal Findings

Mercury treated BALB/c wt mice showed a significant but modest increase of circulating IC (CIC) from day 12 until day 18 and day 35 for IgG2a- and IgG1- CIC, respectively. Mercury-treated mice lacking the trans-membrane γ-chain of activating FcγRs (FcRγ^−/−) had significantly higher CIC levels of both IgG1-CIC and IgG2a-CIC than wt mice during the treatment course. The hepatic uptake of preformed CIC was significantly more efficient in wt mice compared to FcγR^−/− mice, but also development of extrahepatic tissue IC deposits was delayed in FcRγ^−/− mice. After 35 days of Hg treatment the proportion of immune deposits, as well as the amounts was significantly reduced in vessel FcRγ^−/− mice compared to wt mice.

Conclusions

We conclude that mice lacking functional activating FcγRs respond to Hg with increased levels and altered quality of CIC compared with wt mice. Lack of functional activating FcγRs delayed the elimination of CIC, but also significantly reduced extrahepatic tissue localization of CIC.

The endoplasmic reticulum stress-inducible protein, Herp, is a potential triggering antigen for anti-DNA response

Anti-dsDNA Abs are highly specific indicators of systemic lupus erythematosus (SLE) and play a pathogenic role in lupus nephritis. Human anti-dsDNA Abs are most likely generated by an Ag-driven mechanism. However, the Ag responsible for triggering anti-dsDNA Ab production has not been identified. To search for proteins that are cross-reactive with anti-dsDNA Abs, we screened a cDNA library from a patient with SLE with single-chain Fv of O-81 human anti-ss/dsDNA mAb by using a two-hybrid system. Homocysteine-induced ER protein (Herp), an endoplasmic reticulum (ER) stress-inducible ER membrane protein, was identified and shown to bind to original O-81 Ab and human lupus anti-dsDNA Abs. Some IgG purified from patients with active SLE by Herp-immobilized affinity chromatography bound to dsDNA. BALB/c mice immunized with Herp showed IgG anti-dsDNA Abs, IgG anti-nucleosome Abs, and glomerular IgG deposition. Herp reactivity was strongly positive in a proportion of PBLs from patients with active SLE, but undetectable in those from healthy controls. Moreover, activation of caspases was observed in the Herp-positive cells, implying that ER stress-induced apoptosis likely occurs in patients with active SLE. Herp is exposed on blebs of ER stress-induced apoptotic cells, suggesting that Herp can be recognized by immune cells. These results indicate that Herp mimics structural determinants of DNA immunologically and can be immunogenic in vivo. Thus, Herp represents a candidate autoantigen for anti-DNA Abs. This study may help explain how common environmental factors induce the production of anti-DNA Abs and contribute the development of SLE.

Investigation of pathological and clinical features of lupus nephritis in 73 autopsied cases with systemic lupus erythematosus

The aims of this study were to analyze the clinical and pathological features of lupus nephritis (LN) and examine the association between these features and pathological condition, treatment, and prognosis. Of the 177 systemic lupus erythematosus patients who died while receiving inpatient care at Juntendo University Hospital between 1960 and 2001, we investigated the clinical features, treatment, and pathological features of 73 of these who underwent pathological autopsy and had a clear medical history. We divided these cases into two groups, i.e., those up to 1979 (Group A) and those during and after 1980 (Group B) in order to investigate changes in tendencies by age. We also divided the cases into three groups by time interval between diagnosis and death to investigate long-term prognosis. Uremia was the direct cause of death in 38.9% of cases in Group A and only 10.8% of cases in Group B. Pathological features showed a tendency to change to a sclerotic lesion as the duration of the disorder became longer. Uremia attributable to LN was the direct cause of death in relatively fewer cases, although it is still found in the majority of LN cases and remains a problem requiring stringent management. The treatment of sclerotic lesions may be an issue that needs further attention.

Efficacy of enteric-coated mycophenolate sodium in patients with resistant-type lupus nephritis: a prospective study

The role of mycophenolate mofetil (MMF) is still controversial in the treatment of cyclophosphamide-resistant proliferative lupus nephritis (PLN). Enteric-coated mycophenolate sodium (EC-MPS) has less gastrointestinal adverse effects than MMF and is, therefore, increasingly utilised in organ transplantation. The aim of this study was to compare the efficacy and safety of EC-MPS versus an extended-course of intravenous cyclophosphamide (ED-IVCY) in resistant-type PLN. Thirty-one, biopsy-proven PLN, patients who failed to respond to an induction of IVCY were enrolled in a prospective, open-labelled, historically controlled study. Patients received 6 month of EC-MPS (720 mg b.i.d.) treatment. The patients in the ED-IVCY group, collected from a database, received a repeated 6-month course of monthly IVCY 0.5–1 g/m2of body surface area. Both groups received 0.5–1 mg/kg/day of prednisolone. Primary outcomes were partial or complete responses. A repeated kidney biopsy was performed to evaluate the histological response. No serious adverse events or patient deaths were observed during the study. Both groups had comparable baseline characteristics. At 6 months, the EC-MPS group had a comparable response rate with the ED-IVCY group. There were significantly less adverse events in the EC-MPS group. Repeated biopsies showed significant improvement in the EC-MPS group. EC-MPS provides salutary efficacy and safety in the treatment of resistant-type PLN and can be a suitably alternative treatment to ED-IVCY.

Surface rheology of hydrophobically modified PEG polymers associating with a phospholipid monolayer at the air-water interface

Surface rheology of irreversibly bound hydrophobically modified poly(ethylene glycol) (PEG) polymers (HMPEG) on a dipalmitoylphosphatidylcholine (DPPC) monolayer is investigated to determine attributes that may contribute to immune recognition. Previously, three comb-graft polymers (HMPEG136-DP3, HMPEG273-DP2.5, and HMPEG273-DP5) adsorbed on liposomes were examined for their strength of adsorption and protection from complement binding. The data supported an optimal ratio between the hydrophilicity of the PEG polymer and the number of hydrophobic anchors. The HMPEG polymers have different polymer brush thicknesses (4.2-5.9 nm) and levels of cooperativity (2.5-5 hydrophobes). The results indicate that an increased viscous force (above 0.25 mN s/m) at the surface may enable the polymers to shield liposomes from protein interactions. Similar rheological behavior is shown for all polymer architectures at low polymer surface coverage (0.5 mg/m2, in the mushroom regime), whereas at high surface coverage (>0.5 mg/m2, in the brush regime), we observe a structural dependence of the surface viscous forces at 40 mN/m. This threshold correlates with a 92% decrease in complement protein binding for liposomes coated with 1 mg/m2 HMPEG273-DP5. This may suggest that surface viscous forces play a role in reducing complement protein binding.

Renin-angiotensin system gene polymorphisms predict the progression to renal insufficiency among Asians with lupus nephritis

The renin-angiotensin system (RAS) is a strong candidate as a mediator for the development and progression of lupus nephritis (LN). We performed an ethnically stratified analysis of 642 systemic lupus erythematosus (SLE) patients to determine whether various functional RAS gene polymorphisms are associated with SLE renal outcomes. Patients were genotyped for two angiotensin-converting enzyme (ACE) gene polymorphisms: Alu insertion/deletion (I/D) and 23 949 (CT)(2/3), and for two angiotensinogen (Atg) gene polymorphisms: M235T and C-532T. Multivariate analyses demonstrated associations between the ACE I/D, ACE (CT)(2/3) and Atg C-532T functional polymorphisms and LN among Asians. In stratified analyses among LN cases according to high vs low glomerular filtration rate (GFR), associations remained significant for the ACE D (odds ratio (OR) 5.9, P=0.001) and (CT)(2) (OR 6.2, P=0.001) alleles among Asian subjects with low GFR. Lastly, we found allelic dose-dependent associations between the ACE I/D (P=0.003), ACE (CT)(2/3) (P=0.005) and Atg M235T (P=0.04) polymorphisms, and GFR analyzed as a continuous variable among Asians. These findings suggest a significant role for ACE and Atg gene sequence variation and severity of LN among Asians with SLE.

The role of kidney biopsy in the management of lupus nephritis

PURPOSE OF REVIEW

This review evaluates the role of kidney biopsy as a tool in the diagnosis, prognostication and therapeutic management of lupus nephritis. The renal biopsy is the only method available for diagnosing and classifying lupus nephritis. However, disagreements persist regarding the appropriate role of a renal biopsy in the management and identification of predictors of short and long-term outcomes.

RECENT FINDINGS

Recent modifications to the classification of lupus nephritis, the emergence of newer scoring indices, and the availability of a variety of therapeutic options predicate a reassessment of the role of the renal biopsy in the management of lupus nephritis, especially for high-risk patients.

SUMMARY

Despite some controversy, the renal biopsy has been shown to provide information over and above that provided by the clinical variables, and remains a pivotal element in optimizing therapy and the rational management of lupus nephritis.

Role of anti-C1q autoantibodies in the pathogenesis of lupus nephritis

Anti-C1q autoantibodies can be found in the sera of patients with several autoimmune diseases, but also in healthy individuals. Although these anti-C1q autoantibodies were already identified several decades ago, they still puzzle both immunologists and nephrologists. The main reason for this puzzling effect are observations that seemed to indicate quite clearly that anti-C1q should be pathogenic to the kidney and the observation on the other hand that anti-C1q autoantibodies can be found in several disease conditions, as well as in healthy individuals, and are then unrelated to overt renal inflammation. This puzzle is the focus of the current review, which will provide an overview of the historical data, define the clinical interests and, importantly, will try to put several aspects in perspective based on recent observations in patients and in murine models. In addition, the paper will discuss therapeutic intervention possibilities regarding anti-C1q-mediated damage in systemic lupus erythematosus, as well as the therapeutic potential of anti-C1q antibodies in other conditions.

Anti-C1q autoantibodies deposit in glomeruli but are only pathogenic in combination with glomerular C1q-containing immune complexes

Anti-C1q autoantibodies are present in sera of patients with several autoimmune diseases, including systemic lupus erythematosus (SLE). Strikingly, in SLE the presence of anti-C1q is associated with the occurrence of nephritis. We have generated mouse anti-mouse C1q mAb's and used murine models to investigate whether anti-C1q autoantibodies actually contribute to renal pathology in glomerular immune complex disease. Administration of anti-C1q mAb JL-1, which recognizes the collagen-like region of C1q, resulted in glomerular deposition of C1q and anti-C1q autoantibodies and mild granulocyte influx, but no overt renal damage. However, combination of JL-1 with a subnephritogenic dose of C1q-fixing anti-glomerular basement membrane (anti-GBM) antibodies enhanced renal damage characterized by persistently increased levels of infiltrating granulocytes, major histological changes, and increased albuminuria. This was not observed when a non-C1q-fixing anti-GBM preparation was used. Experiments with different knockout mice showed that renal damage was dependent not only on glomerular C1q and complement activation but also on Fcgamma receptors. In conclusion, anti-C1q autoantibodies deposit in glomeruli together with C1q but induce overt renal disease only in the context of glomerular immune complex disease. This provides an explanation why anti-C1q antibodies are especially pathogenic in patients with SLE.

Anti-C1q autoantibodies deposit in glomeruli but are only pathogenic in combination with glomerular C1q-containing immune complexes

Anti-C1q autoantibodies are present in sera of patients with several autoimmune diseases, including systemic lupus erythematosus (SLE). Strikingly, in SLE the presence of anti-C1q is associated with the occurrence of nephritis. We have generated mouse anti-mouse C1q mAb's and used murine models to investigate whether anti-C1q autoantibodies actually contribute to renal pathology in glomerular immune complex disease. Administration of anti-C1q mAb JL-1, which recognizes the collagen-like region of C1q, resulted in glomerular deposition of C1q and anti-C1q autoantibodies and mild granulocyte influx, but no overt renal damage. However, combination of JL-1 with a subnephritogenic dose of C1q-fixing anti-glomerular basement membrane (anti-GBM) antibodies enhanced renal damage characterized by persistently increased levels of infiltrating granulocytes, major histological changes, and increased albuminuria. This was not observed when a non-C1q-fixing anti-GBM preparation was used. Experiments with different knockout mice showed that renal damage was dependent not only on glomerular C1q and complement activation but also on Fcgamma receptors. In conclusion, anti-C1q autoantibodies deposit in glomeruli together with C1q but induce overt renal disease only in the context of glomerular immune complex disease. This provides an explanation why anti-C1q antibodies are especially pathogenic in patients with SLE.