International validation of a urinary biomarker panel for identification of active lupus nephritis in children.

Conventional markers of juvenile-onset systemic lupus erythematosus (JSLE) disease activity fail to adequately identify lupus nephritis (LN). While individual novel urine biomarkers are good at detecting LN flares, biomarker panels may improve diagnostic accuracy. The aim of this study was to assess the performance of a biomarker panel to identify active LN in two international JSLE cohorts.Novel urinary biomarkers, namely vascular cell adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein 1 (MCP-1), lipocalin-like prostaglandin D synthase (LPGDS), transferrin (TF), ceruloplasmin, alpha-1-acid glycoprotein (AGP) and neutrophil gelatinase-associated lipocalin (NGAL), were quantified in a cross-sectional study that included participants of the UK JSLE Cohort Study (Cohort 1) and validated within the Einstein Lupus Cohort (Cohort 2). Binary logistic regression modelling and receiver operating characteristic curve analysis [area under the curve (AUC)] were used to identify and assess combinations of biomarkers for diagnostic accuracy.A total of 91 JSLE patients were recruited across both cohorts, of whom 31 (34 %) had active LN and 60 (66 %) had no LN. Urinary AGP, ceruloplasmin, VCAM-1, MCP-1 and LPGDS levels were significantly higher in those patients with active LN than in non-LN patients [all corrected p values (p c) < 0.05] across both cohorts. Urinary TF also differed between patient groups in Cohort 2 (p c = 0.001). Within Cohort 1, the optimal biomarker panel included AGP, ceruloplasmin, LPGDS and TF (AUC 0.920 for active LN identification). These results were validated in Cohort 2, with the same markers resulting in the optimal urine biomarker panel (AUC 0.991).In two international JSLE cohorts, urinary AGP, ceruloplasmin, LPGDS and TF demonstrate an 'excellent' ability for accurately identifying active LN in children

Neutrophil Gelatinase―Associated Lipocalin Is Instrumental in the Pathogenesis of Antibody-Mediated Nephritis in Mice

OBJECTIVE: The mechanism by which anti-DNA antibodies mediate lupus nephritis has yet to be conclusively determined. Previously, we found that treatment of mesangial cells with anti-DNA antibodies induced high expression of Neutrophil Gelatinase Associated Lipocalin (NGAL), an iron-binding protein upregulated in response to kidney injury. However, whether NGAL is instrumental in pathogenesis, induced as part of repair, or irrelevant to damage/repair pathways, is not known. METHODS: To investigate the role of NGAL in antibody-mediated nephritis, we induced nephrotoxic nephritis by passive antibody transfer to B6 or 129 mice. To determine if NGAL upregulation is instrumental, we compared the severity of renal damage in NGAL wild-type and knock-out mice following induction of nephrotoxic nephritis. RESULTS: We found that kidney NGAL expression, as well as urinary NGAL levels, were significantly increased in nephrotoxic nephritis as compared to control injected mice. Tight correlations were observed between NGAL expression, renal histopathology, and urinary NGAL excretion. NGAL knock-out mice had attenuated proteinuria and improved renal histopathology as compared to wild-type mice. Similarly, following nephritis induction, NGAL injection significantly exacerbated nephritis and decreased survival. NGAL induces apoptosis via caspase-3 activation, and upregulates inflammatory gene expression in kidney cells in vitro and when injected in vivo. CONCLUSION: We conclude that kidney binding of pathogenic antibodies stimulates local expression of NGAL, which plays a crucial role in the pathogenesis of nephritis via promotion of inflammation and apoptosis. NGAL blockade may be a novel therapeutic approach for the treatment of nephritis mediated by pathogenic antibodies, including anti-GBM disease and lupus nephritis

International Consensus For The Dosing Of Corticosteroids In Childhood-Onset Systemic Lupus Erythematosus With Proliferative Lupus Nephritis

Objective: To develop a Standardized Steroid dosing Regimen (SSR) by physicians treating childhood-onset systemic lupus erythematosus (cSLE) complicated by lupus nephritis (LN), using consensus formation methodology. / Methods: Parameters influencing corticosteroid (CS) dosing were identified (Step-1). Data from children with proliferative LN were used to generate Patient Profiles (PP) (Step-2). Physicians rated change in activity of renal and extra-renal cSLE between two consecutive visits and proposed CS dosing (Step-3). Using PP ratings, the SSR was developed (Step-4) with refinements achieved in a physician focus group (Step-5). A second type of PP describing cSLE course for ≥4 months since kidney biopsy were rated to validate the SSR-recommended oral and intravenous CS-dosages (Step-6). PP adjudication was based on majority ratings for both renal and extra-renal disease courses, and consensus level was set at 80%. / Results: Degree of proteinuria, estimated glomerular filtration rate, change in renal and extra-renal disease activity, and time since kidney biopsy influenced CS dosing (Steps-1/2). Considering these parameters in 5,056 PP-ratings from 103 raters, and renal and extra-renal course definitions, CS-dosing rules of the SSR were developed (Steps-3-5). Validation of the SSR for up to 6 months post kidney biopsy was achieved with 1,838 PP-ratings from 60 raters who achieved consensus for oral and intravenous CS dosage as per the SSR (Step-6). / Conclusion: The SSR represents an international consensus on CS dosing for use in patients with cSLE and proliferative LN. The SSR is anticipated to be used for clinical care and standardize CS-dosage during clinical trials