Urine biomarkers in juvenile-onset SLE nephritis

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.

Evaluation of red blood cell distribution width-platelet ratio as a predictor of adverse pregnancy outcomes and disease severity in systemic lupus erythematosus

OBJECTIVE

The red blood cell distribution width to platelet ratio (RPR) is known to reflect systemic inflammation. This study aimed to explore the predictive value of RPR for disease activity and adverse pregnancy outcomes (APOs) in pregnant women with systemic lupus erythematosus (SLE).

METHODS

We retrospectively evaluated case data of all pregnant women with SLE managed at the First Affiliated Hospital of Zhengzhou University from January 2014 to March 2017. Correlations between RPR and SLE clinical disease activity, organ involvement, and maternal complications were analysed. Changes in the RPR and erythrocyte sedimentation rate (ESR) were observed before and after treatment. A receiver operating characteristic (ROC) curve was used to predict disease activity and APOs based on RPR.

RESULTS

A total of 118 patients were enrolled, including 77 in the disease-active group and 41 in the disease-inactive group. The live birth rate was significantly higher in the disease-inactive group than in the disease-active group (P < 0.001). Compared to the disease-inactive group, the number of patients with elevated RPR, anti-dsDNA antibody level, and ESR was significantly higher in the disease-active group, whereas their platelet-lymphocyte ratios and complement 3 and 4 levels were significantly lower. The disease-active group was more likely to experience APOs (P < 0.001), mainly due to premature birth, low birth weight, and pregnancy loss. The ROC curve indicated that RPR had an effect on disease activity and APOs.

CONCLUSION

RPR can be used as a predictor of disease severity and APOs in pregnant women with SLE. Key Points • RPR positively correlated with SLEDAI; patients with elevated RPR have higher disease activity, more organ, and more maternal complications. • Monitoring RPR could better predict disease activity in pregnant patients with SLE and reduce the incidence of maternal complications and APOs.

Cross-sectional study of plasma Axl, ferritin, IGFBP4 and sTNFR2 as biomarkers of disease activity in childhood-onset SLE: A study of the Pediatric Nephrology Research Consortium

OBJECTIVE

To evaluate the performance of 4 plasma protein markers for detecting disease activity in childhood-onset systemic lupus erythematosus (SLE) patients.

METHODS

Eighty-three consecutive pediatric patients fulfilling ≥4 ACR criteria for SLE and twenty-five healthy controls were prospectively recruited for serological testing of 4 protein markers identified by antibody-coated microarray screen, namely Axl, ferritin, IGFBP4 and sTNFR2. SLE disease activity was assessed using SLEDAI-2000 score. Fifty-seven patients had clinically active SLE (SLEDAI score ≥4, or having a flare).

RESULTS

The plasma concentrations of Axl and ferritin were significantly higher in patients with active SLE than inactive SLE. Plasma Axl levels were significantly higher in active renal versus active non-renal SLE patients. Levels of Axl, ferritin and IGFBP4 correlated significantly with SLEDAI scores. Levels of Axl, IFGBP4 and sTNFR2 inversely correlated with plasma complement C3 levels. Only plasma Axl and ferritin levels correlated with degree of proteinuria. These markers were more specific, but less sensitive, in detecting concurrent SLE activity than elevated anti-dsDNA antibody titer or decreased C3. Ferritin and IGFBP4 levels were more specific for concurrent active lupus nephritis than anti-dsDNA or C3. Plasma ferritin was the best monitor of global SLE activity, followed by C3 then Axl, while both Axl and C3 were best monitors of clinical lupus nephritis activity.

CONCLUSION

In childhood-onset SLE patients, plasma ferritin and Axl perform better than traditional yardsticks in identifying disease activity, either global or renal. The performance of these plasma markers should be explored further in longitudinal cohorts of SLE patients.

High-Throughput Sequencing-Based Analysis of T Cell Repertoire in Lupus Nephritis

T cell receptor (TCR)-mediated immune functions are closely related to autoimmune diseases, such as systemic lupus erythematosus (SLE). However, technical challenges used to limit the accurate profiling of TCR diversity in SLE and the characteristics of SLE patients remain largely unknown. In this study, we collected peripheral blood samples from 10 SLE patients with lupus nephritis (LN) who were confirmed by renal biopsy, as well as 10 healthy controls. The TCR repertoire of each sample was assessed by high-throughput sequencing to examine the distinction between SLE subjects and healthy controls. Our results showed statistically significant differences in TCR diversity and usage of TRBV/TRBJ genes between the two groups. A set of signature V–J combinations enabled efficient identification of SLE cases, yielding an area under the curve (AUC) of 0.89 (95% CI: 0.74–1.00). Taken together, our results revealed the potential correlation between the TCR repertoire and SLE status, which may facilitate the development of novel immune biomarkers.

Class IV Lupus Nephritis in the Setting of Serologically Quiescent Disease and Normal Urine Sediment in a Patient with Late-Onset Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease that may affect any organ of the body. Lupus nephritis (LN) is a frequent and serious complication of SLE. We report a case of an 80-year-old woman who was initially diagnosed with late-onset SLE and eventually developed LN in the setting of normal complements, double-stranded DNA, C-reactive protein, erythrocyte sedimentation rate, and urine sediment. She developed abnormal renal function (creatinine of 1.7 mg/dl) and mild proteinuria (1-2+) without hematuria. Renal biopsy showed class IV lupus glomerulonephritis, active and chronic. The patient was started on mycophenolate mofetil which led to improvement of proteinuria and stabilization of creatinine. The suspicion for LN in a patient with late-onset SLE should remain high when there is development of suspicious renal or urinary abnormalities even if laboratory values do not suggest high disease activity and urinary sediment is normal. To our knowledge, this is one of the oldest patients with biopsy-proven LN and late-onset SLE.

Plasma cytokines as potential biomarkers of kidney damage in patients with systemic lupus erythematosus

Background

Systemic lupus erythematosus is a heterogeneous chronic inflammatory autoimmune disorder characterized by an exacerbated expression of cytokines and chemokines in different tissues and organs. Renal involvement is a significant contributor to the morbidity and mortality of systemic lupus erythematosus, and its diagnosis is based on renal biopsy, an invasive procedure with a high risk of complications. Therefore, the development of alternative, non-invasive diagnostic tests for kidney disease in patients with systemic lupus erythematosus is a priority.

Aim

To evaluate the plasma levels of a panel of cytokines and chemokines using multiplex xMAP technology in a cohort of Colombian patients with active and inactive systemic lupus erythematosus, and to evaluate their potential as biomarkers of renal involvement.

Results

Plasma from 40 systemic lupus erythematosus non-nephritis patients and 80 lupus nephritis patients with different levels of renal involvement were analyzed for 39 cytokines using Luminex xMAP technology. Lupus nephritis patients had significantly increased plasma eotaxin, TNF-α, interleukin-17-α, interleukin-10, and interleukin-15 as compared to the systemic lupus erythematosus non-nephritis group. Macrophage-derived chemokine, growth regulated oncogene alpha, and epidermal growth factor were significantly elevated in systemic lupus erythematosus non-nephritis patients when compared to lupus nephritis individuals. Plasma eotaxin levels allowed a discrimination between systemic lupus erythematosus non-nephritis and lupus nephritis patients, for which we performed a receiver operating characteristic curve to confirm. We observed a correlation of eotaxin levels with active nephritis (Systemic Lupus Erythematosus Disease Activity Index). Our data indicate that circulating cytokines and chemokines could be considered good predictors of renal involvement in individuals with systemic lupus erythematosus.

Podocytes contribute, and respond, to the inflammatory environment in lupus nephritis

Lupus nephritis (LN) affects up to 80% of juvenile onset systemic lupus erythematosus patients, leading to end stage renal failure requiring dialysis or transplantation in 10-15%. Podocytes are specialized epithelial cells of the glomerulus known to be a key site of damage in glomerular diseases. However, their roles in LN have yet to be fully identified. This project aims to identify structural and functional roles of podocytes in an in vitro model of LN. Conditionally immortalized podocytes were treated with proinflammatory cytokines (IL-1β, TNF-α, IFN-α, and IFN-γ) alone and in combination in an in vitro model of LN and were assessed for their structural and functional characteristics. Podocytes produce TNF-α, IL-6, IL-8, VEGF, granulocyte-monocyte colony stimulating factor (GM-CSF), and macrophage colony stimulating factor (M-CSF) at relatively low levels under basal conditions; stimulation with IL-1β led to increased secretion of IL-6 ( P = 0.011), IL-8 ( P = 0.05), VEGF ( P = 0.02), and M-CSF ( P = 0.03). Stimulation with TNF-α led to increased secretion of M-CSF ( P = 0.049) and stimulation with IFN-γ led to novel production of IL-10 ( P = 0.036) and interferon-γ-inducible protein-10 ( P = 0.036). Podocytes demonstrate a reduction in the area covered by filamentous-actin in response to IL-1β treatment within 1 h ( P = 0.011), which is restored by 24 h, associated with an increase in the level of intracellular calcium but not with increased cell death. Podocytes contribute to the inflammatory milieu in LN through cytokine/chemokine secretion and respond to the inflammatory milieu via rearrangement of the actin cytoskeleton leading to effacement, a well-known method of protection against apoptosis in these cells. This demonstrates that podocytes are involved in the pathogenesis of LN.

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.

Lupus nephritis biomarkers

Lupus nephritis (LN), a potentially destructive outcome of SLE, is a real challenge in the management of SLE because of the difficulty in diagnosing its subclinical onset and identifying relapses before serious complications set in. Conventional clinical parameters such as proteinuria, GFR, urine sediments, anti-dsDNA and complement levels are not sensitive or specific enough for detecting ongoing disease activity in lupus kidneys and early relapse of nephritis. There has long been a need for biomarkers of disease activity in LN. Such markers ideally should be capable of predicting early sub-clinical flares and could be used to gauge response to therapy, thus obviating the need for serial renal biopsies with their possible hazardous complications. Since urine can be readily obtained, it lends itself as an obvious biological substrate. In this review, the use of urine and serum as sources of lupus nephritis biomarkers is described, and the results of biomarker discovery studies using candidate and proteomic approaches are summarized.

Urinary biomarkers in childhood lupus nephritis

Juvenile-onset systemic lupus erythematosus (JSLE) is a rare, severe multisystem autoimmune disease affecting the kidney (Lupus Nephritis, LN) in up to 80% of children. LN is more severe in children than adults, with potential for irreversible kidney damage requiring dialysis or transplant. Renal biopsy is currently the gold standard for diagnosing and monitoring LN, however, it is invasive and associated with complications. Urine biomarkers have been shown to be better than serum biomarkers in differentiating renal disease from other organ manifestations. Over the past decade, there have been an increasing number of studies investigating specific candidate biomarkers implicated in the pathogenesis of LN or screening for urinary biomarkers using hypothesis free methods. In this review, developments in urine biomarkers for LN will be reviewed, highlighting those that are of relevance to children and have gone through validation in independent international patient cohorts, bringing them close to clinical translation.

Identification of novel urinary biomarkers for assessing disease activity and prognosis of rheumatoid arthritis

To optimize treatment for rheumatoid arthritis (RA), it is ideal to monitor the disease activity on a daily basis because RA activity fluctuates over time. Urine can be collected routinely at home by patients. Recently, we identified four urinary biomarker candidates—gelsolin (GSN), orosomucoid (ORM)1, ORM2 and soluble CD14 (sCD14)—in RA patients through transcriptomic and proteomic studies. Here, we investigated the clinical significance of the aforementioned urinary biomarker candidates in a prospective manner. For the first time, we found that urinary ORM1, ORM2 and sCD14 levels, but not GSN, were elevated in RA patients and had a positive correlation with the status of the disease activity. In particular, urine tests for ORM 1, ORM 2 and sCD14 efficiently represented the presence of high RA activity without the need for measuring blood markers. In a parallel study, a more rapid radiographic progression over 3 years was observed in patients with higher ORM2 levels. Combined measurements of urinary ORM2 and serum C-reactive protein synergistically increased the predictability of the radiographic progression of RA (odds ratio: 46.5). Collectively, our data provide evidence that blood-free, urinary biomarkers are promising surrogates for assessing disease activity and prognosis of RA. We anticipate that our urinary biomarkers will provide novel candidates for patient-driven measurements of RA activity at home and can shift the paradigm from blood to urine testing in the assessment of RA activity and prognosis in hospitals.

Towards new avenues in the management of lupus glomerulonephritis

Renal involvement in systemic lupus erythematosus (SLE) carries substantial morbidity and mortality. Conventional immunosuppressive agents (cyclophosphamide and azathioprine) have suboptimal efficacy and substantial toxicity. Mycophenolate mofetil has emerged as an alternative agent for both induction and maintenance therapy in lupus nephritis because of its reduced gonadal toxicity, despite its failure to demonstrate superiority over cyclophosphamide in pivotal studies. The calcineurin inhibitor tacrolimus has equivalent efficacy to cyclophosphamide and mycophenolate mofetil for inducing remission of lupus nephritis. Although rituximab has shown promise in refractory lupus nephritis, combining rituximab with mycophenolate mofetil as initial therapy offers no additional benefit. Considerable interethnic variation is evident in the efficacy and tolerability of the various immunosuppressive regimens, which necessitates individualized treatment and comparison of the efficacy of new regimens across different ethnic groups. For example, low-dose combinations of tacrolimus and mycophenolate mofetil seem to be more effective than pulse cyclophosphamide as induction therapy in Chinese patients. The same regimen has also been used successfully to treat refractory proliferative and membranous lupus nephritis in patients of various ethnic groups. Finally, novel serum and urinary biomarkers are being validated for diagnosis, prognostic stratification and early recognition of flares in lupus nephritis.

Urinary neutrophil gelatinase-associated lipocalin for diagnosis and estimating activity in lupus nephritis: a meta-analysis

Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is relatively specific in lupus nephritis (LN) patients. However, its diagnostic value has not been evaluated. The aim of this review was to determine the value of uNGAL for diagnosis and estimating activity in LN. A comprehensive search was performed on PubMed, EMBASE, Web of Knowledge, Cochrane electronic databases through December 2014. Meta-analysis of sensitivity and specificity was performed with a random-effects model. Additionally, summary receiver operating characteristic (SROC) curves and area under the curve (AUC) values were calculated. Fourteen studies were selected for this review. With respect to diagnosing LN, the pooled sensitivity and specificity were 73.6% (95% confidence interval (CI), 61.9–83.3) and 78.1% (95% CI, 69.0–85.6), respectively. The SROC-AUC value was 0.8632. Regarding estimating LN activity, the pooled sensitivity and specificity were 66.2% (95% CI, 60.4–71.7) and 62.1% (95% CI, 57.9–66.3), respectively. The SROC-AUC value was 0.7583. In predicting renal flares, the pooled sensitivity and specificity were 77.5% (95% CI, 68.1–85.1) and 65.3% (95% CI, 60.0–70.3), respectively. The SROC-AUC value was 0.7756. In conclusion, this meta-analysis indicates that uNGAL has relatively fair sensitivity and specificity in diagnosing LN, estimating LN activity and predicting renal flares, suggesting that uNGAL is a potential biomarker in diagnosing LN and monitoring LN activity.

The pathogenesis, diagnosis and treatment of lupus nephritis

PURPOSE OF REVIEW

Renal involvement is a major cause of morbidity and mortality in systemic lupus erythematosus. In this review, we provide an update on recent discoveries in the pathogenesis, diagnosis, and treatment of lupus nephritis.

RECENT FINDINGS

Localized long-lived plasma cells have been identified as playing an important role in lupus nephritis. In addition, the roles of aberrant expression of microRNAs and proinflammatory cytokines have been explored. Early diagnosis is important for effective treatment and multiple biomarkers have been identified; however, none has been yet validated for clinical use. Biomarker panels may turn out to be more accurate than each individual component. Biologic agents for the treatment of lupus nephritis are being studied, including belimumab which was recently approved for nonrenal systemic lupus erythematosus. Rituximab has not proven itself in large, placebo-controlled trials, although it is still being used in refractory cases of lupus nephritis.

SUMMARY

Lupus nephritis is a potentially devastating complication of systemic lupus erythematosus. Immune cells, cytokines, and epigenetic factors have all been recently implicated in lupus nephritis pathogenesis. These recent discoveries may enable a paradigm shift in the treatment of this complex disease, allowing the tailoring of treatment to target specific pathogenic mediators at specific points in time in the progression of disease.

VIDEO ABSTRACT

High titer anti-basement membrane antibodies in a subset of patients with pediatric systemic lupus erythematosus

BACKGROUND/AIMS

There is a critical need for more noninvasive biomarkers to identify nephritis in patients with systemic lupus erythematosus (SLE). Recent studies in a model mouse and an adult SLE patient cohort suggest that anti-basement membrane antibody levels correlate well with lupus activity and kidney injury. The purpose of this study was to assess the anti-basement membrane reactivity in pediatric SLE (pSLE) patients with or without nephritis.

METHODS

Auto-antibodies to basement membrane antigens were assessed using an anti-matrigel ELISA. Endpoint titers were measured in pSLE patients and healthy children, as well as in autoimmune and non-immune mice, with good reproducing capabilities. Findings were also analyzed with respect to the presence or absence of nephritis, dsDNA antibodies, and other manifestations of pSLE.

RESULTS

MRL/lpr mice developed high-titer anti-matrigel antibodies, whereas C57BL/6 mice did not. In a cohort of 21 pSLE patients and 22 pediatric controls, high-titer anti-matrigel IgG, IgM and IgA antibody levels were specific for pSLE. High-titer anti-matrigel IgG3 levels could distinguish with good sensitivity the 13 pSLE patients with a history of nephritis from the 8 non-renal pSLE patients. High-titer anti-matrigel IgG, IgA, IgM or IgG3 did not correlate with positive anti-double stranded DNA, but defined an overlapping subset of patients.

CONCLUSION

The addition of anti-basement membrane antibody testing to serologic testing in pSLE may help to monitor disease activity or to define important subsets of patients with risks for specific disease manifestations.

Clinical applications of the indirect immunofluorescence assay for detection of anticell membrane-associated DNA antibodies in juvenile systemic lupus erythematosus

BACKGROUND

Juvenile-onset systemic lupus erythematosus (JSLE) has a higher mortality risk compared to adult-onset SLE. We compared the diagnostic value of anti-cmDNA antibodies with that of antinucleosome antibodies (AnuA), anti-Sm antibodies, and anti-dsDNA antibodies and human B lymphocyte Raji cells with that of human promyelocytic leukemia HL60 cells as substrates in an indirect immunofluorescence assay to detect anti-cmDNA antibodies in JSLE patients.

METHODS

We recruited 92 JSLE patients and 71 patients with other juvenile-onset rheumatic diseases. Anti-cmDNA antibodies and antinuclear antibodies (ANA) were detected in patient sera using indirect immunofluorescence assays. Anti-dsDNA antibodies were detected by combining ELISA and indirect immunofluorescence. Anti-Sm antibodies were detected by double immunodiffusion assay and immunoblotting, while AnuA were detected by ELISA.

RESULTS

The JSLE group had a significantly higher percentage of patients positive for anti-cmDNA compared to patients with other rheumatoid diseases. Using one antibody for diagnosis, anti-cm DNA antibodies had the highest accuracy at 84.0%; using two antibodies, the combination of anti-cm DNA and anti-dsDNA antibodies had 90.8% accuracy. Raji cells used as substrate demonstrated a stronger intensity of fluorescent patterns compared to HL60 cells.

CONCLUSION

The high sensitivity, specificity, and accuracy of detection of anti-cmDNA antibodies make it a valuable diagnostic tool for JSLE.

Predictive role of urinary neutrophil gelatinase-associated lipocalin in lupus nephritis

OBJECTIVES

To evaluate the role of urinary neutrophil gelatinase-associated lipocalin (uNGAL), or lipocalin-2, in systemic lupus erythematosus (SLE) patients as a biomarker of renal activity and flares.

METHODS

Fifty subjects were divided into three groups: the first group comprised 14 SLE patients with no renal disease, the second group 16 SLE patients with active renal disease, the third group 20 apparently normal volunteers. At the beginning of the study clinical and laboratory data including uNGAL were collected. All patients were followed up serially in visits. At each visit, urine samples were collected for measurement of uNGAL as well as for standard urinalysis and a urine protein/creatinine ratio.

RESULTS

A highly significant difference was seen in uNGAL in all studied groups. Correlation was noticed between uNGAL and laboratory parameters of renal disease activity. There was significant positive correlation between renal SLEDAI and uNGAL levels. uNGAL is a significant predictor for renal disease activity and renal flare.

CONCLUSION

The more active the renal disease, the higher the measured levels of uNGAL, suggesting that it is a potential biomarker of active renal disease. uNGAL can be a predictive biomarker that could be followed serially to forecast renal disease activity and lupus nephritis flare.

Urine biomarkers for monitoring juvenile lupus nephritis: a prospective longitudinal study

BACKGROUND

In juvenile-onset systemic lupus erythematosus (JSLE), renal involvement (lupus nephritis) is frequently seen and can result in long-term morbidity. This prospective longitudinal study aimed to identify the utility of standard and/or novel biomarkers for monitoring and predicting lupus nephritis in a real world setting.

METHODS

Using an unselected JSLE cohort, urine samples were collected during routine clinical review. Protein concentrations of urinary monocyte chemo-attractant protein 1 (uMCP1) and neutrophil gelatinase-associated lipocalin (uNGAL) were analysed along with standard disease activity markers, and were compared with current and subsequent disease activity.

RESULTS

JSLE patients (n = 64; median age 14.1 years) were seen at 3 (interquartile range: 2-5) clinical reviews over 364 (182-532) days. Multivariate analysis demonstrated uMCP1 and serum C3 as independent variables (p < 0.001) for active renal disease at the time of the current review. uMCP1 was an excellent predictor of improved renal disease over time (AUC: 0.81; p = 0.013). uNGAL was a good predictor of worsened renal disease activity (AUC 0.76; p = 0.04) over time.

CONCLUSION

Biomarkers (uMCP1, serum C3) can indicate current renal involvement in JSLE, whilst uMCP1 and uNGAL are able to predict subsequent renal disease activity changes. Moving towards biomarker-led monitoring may improve the renal outcome for our patients.

Biomarkers in systemic lupus erythematosus: challenges and prospects for the future

The search for lupus biomarkers to diagnose, monitor, stratify, and predict individual response to therapy is currently more intense than ever before. This effort is essential for several reasons. First, epidemic overdiagnosis and underdiagnosis of lupus, even by certified rheumatologists, leads to errors in therapy with concomitant side effects which may be more serious than the disease itself. Second, identification of lupus flares remains as much an art as it is a science. Third, the capacity to stratify patients so as to predict those who will develop specific patterns of organ involvement is not currently possible but would potentially lead to preventive therapeutic strategies. Fourth, only one new drug for the treatment of lupus has been approved by the US Food and Drug Administration in over 50 years. A major obstacle in this pipeline is the dearth of biomarkers available to prove a patient has responded to an experimental therapeutic intervention. This review will summarize the challenges faced in the discovery and validation of lupus biomarkers, the most promising lupus biomarkers identified to date, and the promise of future directions.

Use of biomarkers in the management of children with lupus

Childhood systemic lupus erythematosus (SLE) is known to have a worse prognosis than adult-onset disease, and monitoring and treatment of the disease are still a challenge. Thus, there is an urgent need for highly reliable, non-invasive biomarkers for early detection of relapses, to avoid long-term complications and to optimize the management of children with LN. Recent studies of pediatric patients have yielded novel specific biomarkers for SLE diagnosis which can be used for monitoring disease activity and response to treatment. The most promising biomarkers in juvenile-onset SLE include cell-bound complement activation products, some genomic profiles, and urinary proteins such as neutrophil gelatinase-associated lipocalin, monocyte chemoattractant protein-1, and alpha-1-acid glycoprotein. None of these might be suitable for use as a single SLE-biomarker. More likely a combination of novel biomarkers with traditionally used data, including autoantibodies and complement, might help to enhance sensitivity and specificity for early diagnosis, disease monitoring, and prediction of relapses.cp.