Evaluation of activity, chronicity and tubulointerstitial indices for childhood lupus nephritis

Do we really need cyclophosphamide for lupus nephritis?

A 14-year-old patient presents with hematuria and proteinuria. Clinical evaluation reveals a positive anti-nuclear antibody titer, positive anti-double stranded DNA antibody and hypocomplementemia. Systemic lupus erythematosus (SLE) is diagnosed based on the 2019 EULAR/ACR (European League Against Rheumatism/American College of Rheumatology) classification criteria (Aringer et al. Arthritis Rheumatol 71:1400-1412, 2019). A kidney biopsy is performed that confirms the presence of immune complex glomerulonephritis, ISN-RPS (International Society of Nephrology/Renal Pathology Society) class IV (Bajema et al. Kidney Int 93:789-796, 2018). According to the latest clinical practice guidelines (Rovin et al. Kidney Int 100:753-779, 2021; Fanouriakis et al. Ann Rheum Dis 83:15-29, 2023), there are alternatives to treating this patient with cyclophosphamide. But what if this patient also presented with oliguria and volume overload requiring intensive care and dialysis? What if this patient also presented with altered mental status and seizures, and was diagnosed with neuropsychiatric lupus? What if this patient was also diagnosed with a pulmonary hemorrhage and respiratory failure? The clinical practice guidelines do not address these scenarios that are not uncommon in patients with SLE. Moreover, in some countries worldwide, patients do not have the privilege of access to biologics or more expensive alternatives. The purpose of this review is to evaluate the contemporary options for initial treatment of nephritis in patients with SLE.

Development of clinical and laboratory biomarkers in an international cohort of 428 children with lupus nephritis

BACKGROUND

Lupus nephritis (LN) is a very severe manifestation of lupus. There is no consensus on which treatment goals should be achieved to protect kidney function in children with LN.

METHODS

We retrospectively analyzed trends of commonly used laboratory biomarkers of 428 patients (≤ 18 years old) with biopsy-proven LN class ≥ III. We compared data of patients who developed stable kidney remission from 6 to 24 months with those who did not.

RESULTS

Twenty-five percent of patients maintained kidney stable remission while 75% did not. More patients with stable kidney remission showed normal hemoglobin and erythrocyte sedimentation rate from 6 to 24 months compared to the group without stable kidney remission. eGFR ≥ 90 ml/min/1.73m2 at onset predicted the development of stable kidney remission (93.8%) compared to 64.7% in those without stable remission (P < 0.00001). At diagnosis, 5.9% and 20.2% of the patients showed no proteinuria in the group with and without stable kidney remission, respectively (P = 0.0001). dsDNA antibodies decreased from onset of treatment mainly during the first 3 months in all groups, but more than 50% of all patients in both groups never normalized after 6 months. Complement C3 and C4 increased mainly in the first 3 months in all patients without any significant difference.

CONCLUSIONS

Normal eGFR and the absence of proteinuria at onset were predictors of stable kidney remission. Significantly more children showed normal levels of Hb and erythrocyte sedimentation rate (ESR) from 6 to 24 months in the group with stable kidney remission.

Urine biomarker score captures response to induction therapy with lupus nephritis

BACKGROUND

The Renal Activity Index for Lupus (RAIL) consists of urine protein assessment of neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, monocyte chemotactic protein 1, adiponectin, hemopexin, and ceruloplasmin, which non-invasively identifies lupus nephritis (LN). We aimed to delineate RAIL scores with inactive versus active LN and changes over time with response to LN induction therapy.

METHODS

There were 128 pediatric patients with systemic lupus erythematosus (SLE) and age-matched healthy controls recruited in a prospective case control study, with kidney biopsy confirmation of LN. Laboratory and clinical information was recorded and urine collected at diagnosis and end of induction and during maintenance therapy. Response to therapy was assessed by repeat kidney biopsy or laboratory parameters. Urine was assayed for RAIL biomarkers and the RAIL score calculated.

RESULTS

Pediatric RAIL (pRAIL) scores from 128 children and young adults with SLE (with/without LN: 70/38) including 25 during LN induction therapy, differentiated clinically active LN from inactive LN or without LN, and controls (all p < 0.0017). pRAIL scores significantly decreased with complete LN remission by 1.07 ± 1.7 (p = 0.03).

CONCLUSIONS

The RAIL biomarkers differentiate LN patients based on activity of kidney disease, with decreases of ≥ 1 in pRAIL scores indicating complete response to induction therapy. Significantly lower RAIL scores in healthy controls and in SLE patients without known LN raise the possibility of subclinical kidney disease. A higher resolution version of the Graphical abstract is available as Supplementary information.

Tertiary lymphoid tissues in kidney diseases: a perspective for the pediatric nephrologist

Chronic kidney disease (CKD) is a major public health problem worldwide. In the pediatric population, CKD is also an important health issue because it causes several comorbid conditions that can have long-term consequences beyond the pediatric age. Chronic inflammation is a common pathological feature of CKD, irrespective of etiology, and leads to maladaptive repair and kidney dysfunction. Tertiary lymphoid tissues (TLTs) are ectopic lymphoid structures that develop in non-lymphoid organs under chronic inflammation caused by pathological conditions, including infections, autoimmune diseases, and cancers. TLTs in the kidneys have been poorly researched due to the lack of an animal model. We have recently found that, in aged but not young mice, TLTs develop in multiple kidney injury models, and the analysis of age-dependent TLTs has brought about several novel insights into the development and pathogenic impacts of TLTs in the kidney. Age-dependent TLT formation is also observed in human kidneys. In addition to aged kidneys, TLT development is also reported in several human kidney diseases including kidney allografts, lupus nephritis, and IgA nephropathy in both adults and children. In this review, we describe the novel findings on TLTs in the kidney obtained mainly from the analysis of age-dependent TLTs and discuss the clinical relevance of TLTs in kidney diseases.

Analysis of Clinicopathological Characteristics and Its Correlation With the Prognosis of Pediatric Lupus Nephritis: A Tertiary Care Center Experience

Aim

To study the various pathological patterns of pediatric lupus nephritis (LN) by renal biopsies and to correlate the histopathological data with the clinical and biochemical outcomes.

Methods

This is a retrospective study in children between 1 month and 18 years of age with renal biopsy-proven lupus nephritis, conducted between January 2015 and December 2019. Various pathological and clinical parameters were compared between the groups with lupus nephritis activity and those without activity.

Results

Of 38 biopsy-proven lupus nephritis cases, 30 (78.9%) were in the adolescent age group, and the female gender was predominantly affected (n=30; 78.9%). Class IV proliferative lupus nephritis (n=17, 44.7%) was the most common biopsy finding, and the activity score for endocapillary hypercellularity, neutrophil infiltration, fibrinoid necrosis, hyaline deposits, and interstitial inflammation was significantly high in classes III and IV. Overall, attaining remission was less, and the risk of progression of chronic kidney disease (CKD) was higher in class IV (n=3; 7.8%). Mortality was reported in 1 out of 38 (2.6%) children.

Conclusion

Light microscopy and immunofluorescence studies play an important role in defining the extent of renal damage in the form of activity and chronicity indices, which are the key factors in the decision-making of lupus nephritis treatment. The prognostic relevance of the histological scoring has been evaluated, and it is evident that the activity index and chronicity index go a long way in therapeutic intervention.

Implication of plasma gelsolin in systemic lupus erythematosus patients

Background

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder with more than one organ involvement. Kidney is the foremost commonly affected one. Gelsolin is a protein that induces depolymerization of actin filaments thus preventing downstream stimulation of inflammatory reactions. The aim of this work was to detect the relation of plasma gelsolin to SLE disease activity and severity indices in order to find out if plasma gelsolin could be used as a biomarker of the disease. This study was conducted on 50 SLE female patients and 30 matched control. SLE disease activity Index (SLEDAI) and SLE damage index (SDI) were assessed. All lupus nephritis (LN) patients were subjected to an ultrasound-guided kidney biopsy. Plasma gelsolin level was measured.

Results

The mean age of the patients was 38.5 ± 6.3 years (26–51 years) with median disease duration of 5 (3–9.3) years. Eighteen patients had LN, 11 had cardiac manifestations and 12 had chest manifestations. The mean SLEDAI was 13.1 ± 4.5 (4–22) and the median SDI was 2 (1–3). Plasma gelsolin level was significantly lower in SLE patients (74.9 mg/l; 57.5–98.8 mg/l) compared to control (801.5 mg/l; 225–1008.3 mg/l) (p < 0.001). There were significant negative correlations of gelsolin levels with anti-ds DNA (r = − 0.63, p < 0.001), SLEDAI (r = − 0.79, p < 0.001), and SDI (r = − 0.74, p = 0.001). Plasma gelsolin level was significantly lower in SLE patients with high/very high activity grades compared to those with low and moderate (p = 0.007 and p < 0.001 respectively). A gelsolin level of ≤ 78.95 mg/l significantly predicted renal affection (p < 0.001), with a sensitivity of 100%, specificity 71.9%, and a positive predictive value 66.7%.

Conclusion

A decreased gelsolin level is associated with disease activity in SLE patients. Plasma gelsolin was well related to disease activity and severity with a high predictive value for renal affection comparable to anti-ds DNA titre. Plasma gelsolin is a potentially important predictive biomarker for SLE and LN.

Change of Renal Gallium Uptake Correlated with Change of Inflammation Activity in Renal Pathology in Lupus Nephritis Patients

Background: Lupus nephritis (LN) often lead to end-stage renal disease in systemic lupus erythematosus patients. This study aimed to investigate the clinical application of renal gallium-67 scans for determining renal histological parameters in LN patients. Methods: Between 2006 and 2018, 237 biopsy-proven and 35 repeat biopsies LN patients who underwent renal gallium scans before or after biopsy were included for analysis. The classification and scoring of LN were assessed according to the International Society of Nephrology/Renal Pathology Society. A delayed 48-h gallium scan was performed and interpreted by semiquantitative methods using left kidney/spine (K/S) ratio. The renal histological results were compared with gallium uptake. Results: Out of 237 participants, 180 (76%) had proliferative LN. Baseline gallium left K/S ratio was significantly higher in class IV LN as compared to class III (median (interquartile range, IQR): 1.16 (1.0–1.3), 0.95 (0.9–1.1), respectively, p < 0.001). Furthermore, changes in gallium uptake between two biopsies were positively correlated with changes activity index (r = 0.357, p = 0.035), endocapillary hypercellularity (r = 0.385, p = 0.032), and neutrophils infiltration (r = 0.390, p = 0.030) in renal pathology. Conclusions: Renal gallium uptake is associated with active inflammation in LN. Changes in renal gallium uptake positively correlated with changes in activity index in renal pathology.

Collagen Type III and VI Remodeling Biomarkers Are Associated with Kidney Fibrosis in Lupus Nephritis

Background

Lupus nephritis (LN) occurs in <40% of patients with SLE. Reliable biomarkers of kidney damage are needed to identify patients with SLE at risk of developing LN to improve screening, treat the disease earlier, and halt progression to kidney failure. Novel biomarkers of extracellular matrix remodeling were evaluated as markers of kidney fibrosis and disease activity in patients with LN.

Methods

Biomarkers of the interstitial collagen type III (PRO-C3) and type VI (PRO-C6) formation and of collagen type III (C3M) degradation were evaluated in the serum and urine of 40 patients with LN, 20 patients with SLE but without LN, 20 healthy controls, and ten biopsy controls (histologic kidney inflammation/damage without SLE). Their association with histologic markers of interstitial fibrosis and tubular atrophy, with inflammatory cell infiltration and with disease activity and chronicity in the patients with LN was assessed.

Results

Despite PRO-C3 (serum) and PRO-C6 (serum and urine) being significantly elevated in patients with LN compared with healthy controls, the markers did not differentiate patients with LN from those with SLE. C3M (urine) levels were not different in LN compared with the other groups. C3M (urine) strongly correlated and PRO-C6 (serum and urine) inversely correlated with kidney function (eGFR). The biomarkers of interstitial collagen turnover PRO-C6 (serum) and C3M (urine) correlated with histologic markers of interstitial fibrosis, tubular atrophy, and monocyte infiltration.

Conclusions

Noninvasive collagen turnover biomarkers are promising tools to identify patients with SLE with kidney histologic modifications.

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.

A comparative study between the disease characteristics in adult-onset and childhood-onset systemic lupus erythematosus in Egyptian patients attending a large university hospital

INTRODUCTION

Disease features and laboratory abnormalities differ among adult-onset and childhood-onset systemic lupus erythematosus (aSLE and cSLE). Socioeconomic status both independent of, and in combination with, ethnicity influences the disease phenotype and outcome.

OBJECTIVE

To compare the various disease features among patients with cSLE and aSLE in a limited monetary income Egyptian cohort attending a large free-of-charge university hospital. Patients and methods: Retrospective analysis of the medical records of 714 SLE patients attending Cairo University Hospitals from January 2000 to December 2019. Of them 602 (400 with aSLE and 202 with cSLE) were enrolled in the study.

RESULTS

The mean age of disease onset was 28.27 ± 10.55 among aSLE patients compared to 12.88 ± 4.26 years among cSLE patients. Disease duration was 12.03 ± 5.05 and 4.14 ± 3.18 years in aSLE and cSLE, respectively. Female to male ratio was 15:1 among patients with aSLE, as compared to 2.67:1 among cSLE (<0.001). Arthritis (69%), oral ulcers (48.5%), neuropsychiatric (18.3%) and thrombotic manifestations of antiphospholipid syndrome (12%) were significantly more frequent in aSLE. On the other hand, renal (67.8%), serositis (49.6%), fever (49%), lymphopenia (40.6%), hemolytic anemia (38.6%), and discoid lupus (13.4%) were significantly more frequent in cSLE. Weight loss, malar rash, photosensitivity, thrombocytopenia, leucopenia and lymphadenopathy were not significantly different between the two groups. Hypocomplementemia, proteinuria, urinary sediments, hematuria were significantly more frequent in cSLE. For those patients with renal involvement, who underwent renal biopsy (58.3% in aSLE and 63.5% in cSLE), there was no significant difference with regard to the different histopathological classes. Anti-Smith, anti-cardiolipin antibodies and rheumatoid factor were significantly more frequent among aSLE patients, while anti-La antibodies were more frequent among cSLE patients.

CONCLUSION

Arthritis was the most common clinical manifestation over time in aSLE compared to renal involvement in cSLE. Renal disease tends to be more active in cSLE. The differences in disease manifestations between this cohort and other studies can be attributed to the ethnic and socioeconomic disparities.

Clinicopathological factors for tubulointerstitial injury in lupus nephritis

OBJECTIVE

To investigate the incidence of tubulointerstitial injury in lupus nephritis (LN) and to examine clinicopathological factors that could indicate the presence of tubulointerstitial injury.

METHODS

This study included 98 patients with LN. Clinical data and the pathological results of the initial renal biopsy were collected.

RESULTS

The frequency of each tubulointerstitial injury parameter was over 50%, except for the interstitial edema, in the 98 patients investigated in this study. The most frequently detected tubulointerstitial injury parameter was tubular atrophy in this study. Neutrophil infiltration/karyorrhexis, wire loop lesion, and arteriosclerosis were observed frequently in patients with tubulointerstitial injuries. High serum creatinine and blood urea nitrogen (BUN) were observed more frequently in patients with tubulointerstitial injuries except tubular degeneration. The multivariable regression analysis showed a relationship between neutrophil infiltration/karyorrhexis and interstitial fibrosis/tubular degeneration, a relationship between wire loop lesion and tubulointerstitial inflammation/edema, and a relationship between arteriosclerosis and tubulointerstitial injuries (except interstitial edema). Patients with tubular degeneration had lower D-Dimer levels compared with those without. Patients with interstitial fibrosis had higher blood leukocyte counts than those without. The rate of low response to therapy was 13% among those without tubulointerstitial inflammation, but 35% in those with interstitial inflammation (P = 0.03).

CONCLUSION

Acute and chronic renal tubulointerstitial lesions are often found along with glomerular and vascular lesions. Immune and vascular factors are probably involved in tubulointerstitial injuries. Tubulointerstitial inflammation may be the initiator of chronic renal injury and may predict response to therapy.Key Points•To provide a theoretical basis for tubulointerstitial injury in LN.

Lupus Nephritis

Childhood-onset systemic lupus erythematosus (SLE) is a subset of SLE with an onset before 18 years of age. Patients with early onset SLE tend to have a greater genetic component to their disease cause, more multisystemic involvement, and a more severe disease course, which includes greater risks for developing nephritis and end-stage kidney disease. Five- and 10-year mortality is lower than in adult-onset SLE. Although patient and renal survival have improved with advances in induction and maintenance immunosuppression, accumulation of irreversible damage is common. Cardiovascular and infectious complications are frequent, as are relapses during adolescence and the transition to adulthood.

Outcomes in juvenile onset lupus: single center cohort from a developing country

Introduction About 10-20% of systemic lupus erythematosus (SLE) patients have onset in childhood and have more severe organ involvement. Survival of juvenile SLE patients is improving worldwide. Long-term data of childhood onset SLE from developing countries is scarce. Methods Clinical and laboratory data at initial presentation and follow-up visits were retrieved from clinic files, hospital information system and personal interviews. Treatment received, complications, flares, outcomes and death were recorded. Survival was calculated using Kaplan-Meier survival curves and regression analysis was done for predictors of mortality. Results Children with SLE ( n = 273, 250 girls) had a median age at onset of 14 years and duration of illness prior to diagnosis at our hospital of 1 year. Fever and arthritis were the most common presenting manifestations. Renal disease was seen in 60.5% and central nervous system (CNS) disease in 29%. The median follow-up period in 248 patients was 3.5 years. Fourteen children died, and 10 of these had active disease at the time of death. The mean actuarial survival was 24.5 years and survival rates at 1, 5 and 10 years were 97.9%, 95% and 89% respectively. Fever, CNS disease, anti-dsDNA levels and serious infections predicted death on univariate and multivariate analysis. Infections were seen in 72 children (26.3%), and 38 of these infections were serious. One-third of the patients had damage on the last follow-up. Flares were seen in 120 children, the majority being major flares. Conclusion Outcomes of pediatric SLE in North Indian children are similar to those seen in developed countries. Infections pose a major challenge in these patients.

Development of a Novel Renal Activity Index of Lupus Nephritis in Children and Young Adults

OBJECTIVE

Noninvasive estimation of the degree of inflammation seen on kidney biopsy with lupus nephritis (LN) remains difficult. The objective of this study was to develop a Renal Activity Index for Lupus (RAIL) that, based solely on laboratory measures, accurately reflects histologic LN activity.

METHODS

We assayed traditional LN laboratory tests and 16 urine biomarkers (UBMs) in children (n = 47) at the time of kidney biopsy. Histologic LN activity was measured by the National Institutes of Health activity index (NIH-AI) and the tubulointerstitial activity index (TIAI). High LN-activity status (versus moderate/low) was defined as NIH-AI scores >10 (versus ≤10) or TIAI scores >5 (versus ≤5). RAIL algorithms that predicted LN-activity status for both NIH-AI and TIAI were derived by stepwise multivariate logistic regression, considering traditional biomarkers and UBMs as candidate components. The accuracy of the RAIL for discriminating by LN-activity status was determined.

RESULTS

The differential excretion of 6 UBMs (neutrophil gelatinase-associated lipocalin, monocyte chemotactic protein 1, ceruloplasmin, adiponectin, hemopexin, and kidney injury molecule 1) standardized by urine creatinine was considered in the RAIL. These UBMs predicted LN-activity (NIH-AI) status with >92% accuracy and LN-activity (TIAI) status with >80% accuracy. RAIL accuracy was minimally influenced by concomitant LN damage. Accuracies between 71% and 85% were achieved without standardization of the UBMs. The strength of these UBMs to reflect LN-activity status was confirmed by principal component and linear discriminant analyses.

CONCLUSION

The RAIL is a robust and highly accurate noninvasive measure of LN activity. The measurement properties of the RAIL, which reflect the degree of inflammatory changes as seen on kidney biopsy, will require independent validation.

Redefining lupus nephritis: clinical implications of pathophysiologic subtypes

Systemic lupus erythematosus (SLE) is associated with a broad spectrum of clinical and immunologic manifestations, of which lupus nephritis is the most common cause of morbidity and mortality. The development of nephritis in patients with SLE involves multiple pathogenic pathways including aberrant apoptosis, autoantibody production, immune complex deposition and complement activation. The 2003 International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification system for lupus nephritis was widely accepted with high intraobserver and interobserver concordance to guide therapeutic strategy and provide prognostic information. However, this classification system is not based on the underlying disease pathophysiology. Some additional lesions that contribute to disease presentation, including glomerular crescents, podocyte injury, tubulointerstitial lesions and vascular injury, should be recognized. Although outcomes for patients with lupus nephritis have improved over the past 30 years, treatment of this disease remains challenging and is best approached on the basis of the underlying pathogenesis, which is only partially represented by the various pathological phenotypes defined by the ISN/RPS classification. Here, we discuss the heterogeneous mechanisms involved in the pathogenesis of lupus nephritis and how improved understanding of underlying disease mechanisms might help guide therapeutic strategies.

Advances in the care of children with lupus nephritis

The care of children with lupus nephritis (LN) has changed dramatically over the past 50 y. The majority of patients with childhood-onset systemic lupus erythematosus (cSLE) develop LN. In the 1960's, prognosis in children was worse than in adults; therapies were limited and toxic. Nearly half of cases resulted in death within 2 y. Since this time, several diagnostic recommendations and disease-specific indices have been developed to assist physicians caring for patients with LN. Pediatric researchers are validating and adapting these indices and guidelines for the treatment of LN in cSLE. Classification systems, activity, and chronicity indices for kidney biopsy have been validated in pediatric cohorts in several countries. Implementation of contemporary immunosuppressive agents has reduced treatment toxicity and improved outcomes. Biomarkers sensitive to LN in children have been identified in the kidney, urine, and blood. Multi-institutional collaborative networks have formed to address the challenges of pediatric LN research. Considerable variation in evaluation and treatment has been addressed for proliferative forms of LN by development of consensus treatment practices. Patient survival at 5 y is now 95-97% and renal survival exceeds 90%. Moreover, international consensus exists for quality indicators for cSLE that consider the unique aspects of chronic disease in childhood.

Serum IL-18 as biomarker in predicting long-term renal outcome among pediatric-onset systemic lupus erythematosus patients

An urge of biomarker identification is needed to better monitor lupus nephritis (LN) disease activity, guide clinical treatment, and predict patient's long-term outcome. With the proinflammatory effect and its association with inflammasomes, the significance of interleukin-18 (IL-18) among pediatric-onset systemic lupus erythematous (pSLE) patient, especially, its importance in predicting long-term renal outcome was investigated.In a pSLE cohort of 96 patients with an average follow-up period of 10.39 ± 3.31 years, clinical data and laboratory workups including serum IL-18 were collected at time of disease onset and 6 months after treatment despite their initial renal status. Through Cox regression analysis, the parameters at baseline and at 6 months posttreatment were carefully analyzed.Average age of all cases was 12.74 ± 3.01 years old and 65 of them underwent renal biopsy at the time of diagnosis. Nine subjects (9.38%) progressed to end-stage renal disease (ESRD) and 2 cases (2.08%) died during follow-up. Through multivariate analysis, serum IL-18 level 6 months posttreatment was found to be the most unfavorable factor associating poor clinical outcome despite patient's initial renal status. In addition, the presentation of serum IL-18 in its correlation with SLE global disease activity as well as the presence and severity of LN were all significant (P < 0.001, P = 0.03, and P = 0.02, respectively). The histological classification of LN, however, was not associated with the level of IL-18 among the pSLE patients (P = 0.64).The role of serum IL-18 as biomarker representing global disease activity and status of renal flares among pSLE population was shown for the first time. Additionally, we have identified IL-18 at 6 months posttreatment a novel marker for long-term renal outcome prediction.

Validation of the Lupus Nephritis Clinical Indices in Childhood-Onset Systemic Lupus Erythematosus

OBJECTIVE

To validate clinical indices of lupus nephritis activity and damage when used in children against the criterion standard of kidney biopsy findings.

METHODS

In 83 children requiring kidney biopsy, the Systemic Lupus Erythematosus Disease Activity Index renal domain (SLEDAI-R), British Isles Lupus Assessment Group index renal domain (BILAG-R), Systemic Lupus International Collaborating Clinics (SLICC) renal activity score (SLICC-RAS), and SLICC Damage Index renal domain (SDI-R) were measured. Fixed effects and logistic models were calculated to predict International Society of Nephrology/Renal Pathology Society (ISN/RPS) class; low-to-moderate versus high lupus nephritis activity (National Institutes of Health [NIH] activity index [AI]) score: ≤10 versus >10; tubulointerstitial activity index (TIAI) score: ≤5 versus >5; or the absence versus presence of lupus nephritis chronicity (NIH chronicity index) score: 0 versus ≥1.

RESULTS

There were 10, 50, and 23 patients with ISN/RPS class I/II, III/IV, and V, respectively. Scores of the clinical indices did not differentiate among patients by ISN/RPS class. The SLEDAI-R and SLICC-RAS but not the BILAG-R differed with lupus nephritis activity status defined by NIH-AI scores, while only the SLEDAI-R scores differed between lupus nephritis activity status based on TIAI scores. The sensitivity and specificity of the SDI-R to capture lupus nephritis chronicity was 23.5% and 91.7%, respectively. Despite being designed to measure lupus nephritis activity, SLICC-RAS and SLEDAI-R scores significantly differed with lupus nephritis chronicity status.

CONCLUSION

Current clinical indices of lupus nephritis fail to discriminate ISN/RPS class in children. Despite its shortcomings, the SLEDAI-R appears best for measuring lupus nephritis activity in a clinical setting. The SDI-R is a poor correlate of lupus nephritis chronicity.

Absolute Quantitative Evaluation of 67Ga Scintigraphy in Lupus Nephritis

PURPOSE

Renal biopsy is crucial for management of lupus nephritis. However, it is invasive and can cause bleeding and infection. In our previous study, we developed a semiquantitative method for gallium renal imaging and demonstrated a good correlation between the left kidney-to-spine ratio (K/S ratio) and the results of renal biopsy. However, the accuracy of left K/S ratio is compromised by the variation of spinal gallium uptake, especially in patients with extraordinarily high or low gallium uptakes in the spine. In this study, we developed an absolute quantitative method and compared the results of quantitative gallium images, semiquantitative gallium images, visual methods, and renal biopsies.

METHODS

Thirty-four patients with lupus nephritis were enrolled and underwent renal biopsy to determine activity index (AI) and chronicity index. A delayed 48-hour gallium scan was also performed and interpreted by visual, semiquantitative, and absolute quantitative methods. For absolute quantitative analysis, a standard solution with activities of approximately 555 KBq (15 μCi) was prepared and poured into a 5-mL tube, which was placed close to the patient. ROIs were drawn around the outer edge of the left kidney as well as around the outer edges of the standard. A kidney uptake index (KUI) was calculated, and the results were compared with K/S ratio, visual grading, and renal biopsies.

RESULTS

Kidney uptake index had the best correlation with AI among the 3 methods using Spearman rank correlation test. The Spearman R values were 0.78, 0.71, and 0.61 for KUI, K/S ratio and visual grading, respectively. Chronicity index did not correlate well with the results of any of the 3 methods. In addition, AI was significantly higher in patients with a KUI equal to or greater than 1.5, when compared with patients with a KUI lower than 1.5 (P = 0.00001 by Mann-Whitney U test). Using a K/S ratio of 0.95 as a cutoff value, AI also showed a statistically significant difference with P = 0.0001. When a visual grading of 2 was used as a cutoff value, P = 0.0008. The difference in AI was most significant when the statistical value was based on the KUI.

CONCLUSIONS

The KUI showed better correlation with the results of renal biopsy than the K/S ratio and the visual grading. We suggest that the KUI from the absolute quantitative renal gallium scintigraphy may be a useful parameter for evaluating the disease activity in lupus nephritis.

Long-term renal outcomes of childhood-onset global and segmental diffuse proliferative lupus nephritis

BACKGROUND

Data on global (IV-G) and segmental (IV-S) diffuse proliferative lupus nephritis (DPLN) in children are lacking.

METHODS

To determine the clinicopathology and prognosis of DPLN subclasses IV-G and IV-S, we analyzed the clinical, laboratory, and demographic data of 56 children aged <18 years diagnosed with DPLN [36 (64.3%) with IV-G; 20 (35.7%) with IV-S] between 2004 and 2013. Clinical endpoints were: (1) complete remission (CR), (2) chronic kidney disease [CKD; defined as estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m(2) or end-stage renal disease (ESRD)], and (3) death.

RESULTS

Proteinuria and the activity index were higher in patients with IV-G (p < 0.05). Global endocapillary proliferation and leukocyte exudation were predominant in IV-G patients, whereas segmental endocapillary proliferation was predominant in patients with IV-S (p < 0.005). CR rates in IV-G and IV-S patients were 50 and 60%, respectively (p = 0.47). Renal survival rates, defined as an eGFR of ≥60 mL/min/1.73 m(2), were 93, 78, and 64% at 1, 5, and 10 years, respectively. Patient survival rates at 1, 5, and 10 years were 98, 96, and 91%, respectively. Patient and renal survival rates were similar in both subclasses.

CONCLUSIONS

Although patients with IV-G and IV-S displayed some clinical and histopathological disparities, renal outcomes were similar. The majority of children with DPLN reached adulthood but accrued significant renal damage. Treatment regimens which can slow the progression of CKD are needed.

Practice patterns and approach to kidney biopsy in lupus: a collaboration of the Midwest Pediatric Nephrology Consortium and the Childhood Arthritis and Rheumatology Research Alliance

BACKGROUND

There is no clear consensus regarding optimal indications or timing of initial or repeat kidney biopsy in the management of pediatric systemic lupus erythematosus (pSLE).

METHODS

A web-based survey was designed to assess current practice patterns among pediatric nephrologists and pediatric rheumatologists and distributed to members of Midwest Pediatric Nephrology Consortium (MWPNC) and Childhood Arthritis and Rheumatology Research Alliance (CARRA).

RESULTS

Respondents included 111 rheumatologists and 71 nephrologists from 65 and 34 centers, respectively. Numbers of years in sub-specialty practice were comparable. Rheumatologists and nephrologists frequently collaborate in the care of children with lupus nephritis (LN). More than 90% of respondents refer patients to each either other after diagnosing LN. Over 60% describe shared decision making regarding when to perform kidney biopsy and how to interpret biopsy findings. Many pediatric nephrologists consider biopsy to be of higher risk for complication in pSLE and alter their standard pre-or post-biopsy management.

CONCLUSIONS

It is uncommon for pediatric nephrologists to manage LN without input from pediatric rheumatologists and vice versa. Consensus exists between specialties in general, and practice differences that exist occur between individual physicians rather than between specialties. A systematic approach to biopsy may result in improved health related outcomes in pSLE.

Similarities and differences between pediatric and adult patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease with highest prevalence among women of childbearing age. However, children younger than 16 years also can develop SLE (childhood-onset lupus/juvenile-type SLE). The aim of our study was to compare the clinical course of adult and pediatric-onset SLE. Data from 342 adult patients followed at the University of Debrecen, Hungary, and 79 children documented in the Hungarian National Pediatric SLE registry were analyzed using hospital medical records. Organ manifestations, laboratory parameters, and immunoserological characteristics were reviewed and the results were evaluated using SPSS for Windows software.Gender distribution was not significantly different between groups with disease starting in childhood vs adulthood. The prevalence of the following manifestations was significantly higher for pediatric than for adult-onset disease including: lupus nephritis (43% pediatric vs 26.4% for adult-onset), hematological disorders (57% vs 36.4%), photosensitivity (20% vs 9%), butterfly rash (61% vs 35.5%) and mucosal ulceration (11.4% vs 4%). For adult-onset SLE, neurological symptoms (30% vs 6%) and polyarthritis (86% vs 68%) occurred significantly more frequently than in children. Anti-SSA, anti-SSB and antiphospholipid antibodies were detected at significantly higher levels in adult-onset patients compared to those in pediatrics. Children were more commonly given high-dose intravenous immunoglobulin treatment (6.3% vs 0.6%) and mycophenolate mofetil (15.2% vs 5.3%) than adults.These results suggest that pediatric and adult-onset SLE differ in multiple aspects, and it is important to recognize these differences for optimal treatment and prognosis of these patients.

Update on differences between childhood-onset and adult-onset systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease and occurs worldwide in both children and adults. The estimated annual incidence among children is 2.22/100,000 and among adults is 23.2/100,000 in the United States. There is increasing understanding about differences in disease manifestations, medication use, and disease severity between those with childhood-onset SLE as compared with adult-onset SLE. Children have a more fulminant disease onset and course than adults with SLE, resulting in two to three times higher mortality. In future years, we anticipate more insight into the genetics between childhood-onset SLE and adult-onset SLE to help delineate the best therapies for both subsets of patients.

Biomarkers and updates on pediatrics lupus nephritis

Lupus nephritis is a common complication of systemic lupus erythematosus in children and adolescents. This article reviews the clinical relevance of lupus nephritis and its current treatment. The reader is introduced to novel biomarkers that are expected to improve the management of lupus nephritis in the future, and support the testing of novel medication regimens.

Analysis of clinicopathologic correlations in Iranian patients with lupus nephritis

OBJECTIVE

To determine clinical features of different histopathological presentations in patients with lupus nephritis (LN).

METHODS

Clinical and pathological features of 71 biopsy-proven LN patients were analyzed in a cross-sectional study during 2005-2011.

RESULTS

Sixty-five women (91.5%) and six men (8.5%) were studied. The mean Activity Index (AI) and Chronicity Index (CI) were 6.2 ± 3.1 and 1.7 ± 1.5, respectively. The most common histopathologic presentation of kidneys was class IV (52.1%). Patients with more advanced International Society of Nephrology and the Renal Pathology Society (ISN/RPS) classes, had longer disease duration (P = 0.007), higher levels of blood urea nitrogen (P = 0.004) and serum creatinine (P = 0.035). The most frequent active lesion seen in renal biopsies was endocapillary hypercellularity (83.1%) while glomerular sclerosis was the most common chronic lesion (52.1%). Patients with chronic lesions, including glomerular sclerosis (P = 0.032), fibrous crescent (P = 0.001), interstitial fibrosis (P = 0.025) and tubular atrophy (P = 0.049) had higher serum creatinine levels. Hypertension was mainly seen in patients who had interstitial fibrosis and tubular atrophy (P = 0.026, 0.002 respectively). Moreover, subjects with renal failure had been more frequently involved with fibrinoid necrosis/karyorrhexis (P = 0.003), interstitial inflammation (P = 0.009), fibrous crescents (P = 0.041), tubular atrophy (P = 0.008) and interstitial fibrosis (P < 0.001).

CONCLUSION

We found that both histopathologic classification (ISN/RPS criteria) and histopathologic grading (US National Institutes of Health activity and chronicity indices) correlate to some clinical manifestations of LN. Considering these correlations may help to determine the patients' clinicopathologic status, prognosis and the need to immediate treatment. Nevertheless, it is necessary to clarify the accuracy of these findings in larger-scale prospective studies.

Association of noninvasively measured renal protein biomarkers with histologic features of lupus nephritis

OBJECTIVE

To investigate the relationship of urinary biomarkers and established measures of renal function to histologic findings in lupus nephritis (LN), and to test whether certain combinations of the above-mentioned laboratory measures are diagnostic for specific histologic features of LN.

METHODS

Urine samples from 76 patients were collected within 2 months of kidney biopsy and assayed for the urinary biomarkers lipocalin-like prostaglandin D synthase (L-PGDS), α(1) -acid glycoprotein (AAG), transferrin (TF), ceruloplasmin (CP), neutrophil gelatinase-associated lipocalin (NGAL), and monocyte chemotactic protein 1 (MCP-1). Using nonparametric analyses, levels of urinary biomarkers and established markers of renal function were compared with histologic features seen in LN, i.e., mesangial expansion, capillary proliferation, crescent formation, necrosis, wire loops, fibrosis, tubular atrophy, and epimembranous deposits. The area under the receiver operating characteristic curve (AUC) was calculated to predict LN activity, chronicity, or membranous LN.

RESULTS

There was a differential increase in levels of urinary biomarkers that formed a pattern reflective of specific histologic features seen in active LN. The combination of MCP-1, AAG, and CP levels plus protein:creatinine ratio was excellent in predicting LN activity (AUC 0.85). NGAL together with creatinine clearance plus MCP-1 was an excellent diagnostic test for LN chronicity (AUC 0.83), and the combination of MCP-1, AAG, TF, and creatinine clearance plus C4 was a good diagnostic test for membranous LN (AUC 0.75).

CONCLUSION

Specific urinary biomarkers are associated with specific tissue changes observed in conjunction with LN activity and chronicity. Especially in combination with select established markers of renal function, urinary biomarkers are well-suited for use in noninvasive measurement of LN activity, LN chronicity, and the presence of membranous LN.

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.

Pediatric lupus--are there differences in presentation, genetics, response to therapy, and damage accrual compared with adult lupus?

Some complement deficiencies predispose to systemic lupus erythematosus (SLE) early in life. Currently, there are no known unique physiologic or genetic pathways that can explain the variability in disease phenotypes. Children present with more acute illness and have more frequent renal, hematologic, and central nervous system involvement compared to adults with SLE. Almost all children require corticosteroids during the course of their disease; many are treated with immunosuppressive drugs. Mortality rates remain higher with pediatric SLE. Children and adolescents accrue more damage, especially in the renal, ocular and musculoskeletal organ systems. Conversely, cardiovascular mortality is more prevalent in adults with SLE.

Metabolic syndrome risk factors and estimated glomerular filtration rate among children and adolescents

The aim of this study was to seek the possible relationship between estimated glomerular filtration rate (e-GFR) and anthropometric indexes, lipids, insulin sensitivity, and metabolic syndrome risk factors among healthy children and adolescents. Sufficient evidence suggest that obesity is related with a novel form of glomerulopathy named obesity-related glomerulopathy (ORG) among adults, children, and adolescents. Glomerular filtration rate was estimated from serum creatinine in 166 healthy children and adolescents [79 males, 87 females; age 10.6 +/- 3.3 (3-18) years]. Anthropometric indexes and systolic and diastolic blood pressure were measured. Fasting insulin, glucose, creatinine, uric acid, total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, and triglycerides were estimated. Insulin sensitivity was estimated from known formulas. The presence of certain metabolic syndrome risk factors was checked among the studied population. Boys showed higher e-GFR rates than girls (f = 8.49, p = 0.004). We found a strong positive correlation between e-GFR and body weight (r = 0.415), body mass index (BMI) (r = 0.28), waist circumference (r = 0.419), hip circumference (r = 0.364), birth weight (r = 0.164), systolic blood pressure (SBP) (r = 0.305), and mean arterial pressure (MAP) (r = 0.207). A negative correlation was found between e-GFR and fasting glucose (r = -0.19), total cholesterol (r = -0.27) and LDL-cholesterol (r = -0.26). Clustering of metabolic syndrome risk factors among certain individuals was correlated with higher e-GFR rates (f = 3.606, p = 0.007). The results of this study suggest that gender, anthropometric indexes, and SBP are strong positive determinants of e-GFR among children and adolescents. Waist circumference is the most powerful determinant of e-GFR. Fasting glucose and lipid abnormalities are negative determinants of e-GFR among the studied population. Clustering of metabolic syndrome risk factors is coupled with higher e-GFR rates.

Tubulointerstitial lesions of patients with lupus nephritis classified by the 2003 International Society of Nephrology and Renal Pathology Society system

The 2003 International Society of Nephrology/Renal Pathology Society (ISN/RPS) system for classifying patients with lupus nephritis was based on glomerular lesions exclusively, despite the fact that lupus nephritis affects all compartments of the kidney. Hence, we analyzed the tubulointerstitial lesions in patients with lupus nephritis within the different classes and subclasses of the 2003 ISN/RPS system. Among 313 patients from five centers in northern China with lupus nephritis, interstitial inflammatory cell infiltration, tubular atrophy, and interstitial fibrosis were severe in 170 patients with class IV, moderate in 55 with class III, and mild in 19 with class II and in 69 with class V disease, each with significance. The severity of tubulointerstitial lesions in classes IV-segmental and III was similar, whereas the score of interstitial inflammatory cell infiltration in patients with subclass IV-global was significantly higher than that in those with subclass IV-segmental. Interstitial fibrosis and tubular atrophy were each significantly more prominent in patients with both active and chronic lesions than in those with active lesions alone. The correlation coefficient ranged from 0.222 to 0.811 comparing glomerular and tubulointerstitial indices. In multivariate Cox hazard analysis of tubulointerstitial lesions, indices of interstitial infiltration, tubular atrophy, and interstitial fibrosis were confirmed as significant independent risk factors for renal outcome. Thus, we found that the 2003 ISN/RPS classification system of lupus nephritis, based on glomerular lesions, could also reflect related tubulointerstitial lesions. Hence, we suggest that the extent of tubulointerstitial lesions may be helpful in predicting renal outcome in patients with lupus nephritis.

Neutrophil gelatinase-associated lipocalin is a predictor of the course of global and renal childhood-onset systemic lupus erythematosus disease activity

OBJECTIVE

To determine whether neutrophil gelatinase-associated lipocalin (NGAL) can predict worsening of global and renal disease activity in childhood-onset systemic lupus erythematosus (SLE).

METHODS

One hundred eleven patients with childhood-onset SLE were enrolled in a longitudinal, prospective study with quarterly study visits and had at least 3 study visits. At each visit, global disease activity was measured using 3 external standards: the numerically converted British Isles Lupus Assessment Group (BILAG) index, the SLE Disease Activity Index 2000 update score, and the physician's assessment of global disease activity. Renal and extrarenal disease activity were measured by the respective domain scores. The disease course over time was categorized at the most recent visit (persistently active, persistently inactive, improved, or worsening). Plasma and urinary NGAL levels were measured by enzyme-linked immunosorbent assay, and urinary NGAL levels were standardized to the urinary creatinine concentration. The longitudinal changes in NGAL levels were compared with the changes in SLE disease activity using mixed-effect models.

RESULTS

Significant increases in standardized urinary NGAL levels of up to 104% were detected up to 3 months before worsening of lupus nephritis (as measured by all 3 external standards). Plasma NGAL levels increased significantly by as much as 26% up to 3 months before worsening of global SLE disease activity as measured by all 3 external standards. Plasma NGAL levels increased significantly by 26% as early as 3 months prior to worsening of lupus nephritis as measured by the BILAG renal score.

CONCLUSION

Serial measurement of urinary and plasma NGAL levels may be valuable in predicting impending worsening of global and renal childhood-onset SLE disease activity.