Role of early repeated renal biopsies in lupus nephritis

Utility of a repeat renal biopsy in lupus nephritis: a single centre experience

Background

The role of repeat renal biopsy in lupus nephritis (LN) to guide treatment or predict prognosis has been controversial. We assessed glomerular and tubulointerstitial histological characteristics of serial renal biopsies, correlations with clinical variables and the impact on subsequent management.

Methods

Out of a large single-centre cohort of 270 biopsy-proven LN patients, 66 (24%) had serial biopsies. LN classes based on glomerular pathology were defined according to the International Society of Nephrology/Renal Pathology Society 2003 classification, while tubulointerstitial pathologies were evaluated using the revised Austin's semi-quantitative scoring system.

Results

LN class transitions from proliferative (III and IV) to non-proliferative classes (II and V) were uncommon (n = 4, 7.7%), while non-proliferatives frequently switched to proliferative classes (n = 12, 63.2%) and were more likely to receive increased immunosuppression (P = 0.040). Biochemical or serological variables could not predict these histopathological transitions. Tubulointerstitial score (mean ± standard deviation) progressed from 2.69 ± 2.03 on reference to 3.78 ± 2.03 on repeat biopsy (P = 0.001). Serum creatinine levels correlated with the degree of tubular atrophy on both reference (r = 0.33, P = 0.048) and repeat biopsy (r = 0.56, P < 0.001), and with interstitial scarring (r = 0.60, P < 0.001) on repeat biopsy. Greater interstitial inflammation on reference biopsy was associated with advanced interstitial scarring on repeat biopsies (r = 0.385, P = 0.009).

Conclusions

Repeat renal biopsy is an important tool to guide management, in particular in those with initial class II or V who flare. Although class transitions cannot be predicted by clinical parameters, serum creatinine level correlates with the degree of tubulointerstitial damage.

Management of refractory lupus nephritis: challenges and solutions

Refractory lupus nephritis, broadly defined as failure to attain clinical remission after appropriate induction immunosuppressive therapy, is associated with an increased risk of progression to end-stage kidney disease and mortality. This is a challenging issue in clinical practice, as modern induction therapy despite proven efficacy can still be associated with treatment failure. Moreover, newer therapies have failed in recent years to displace or even match existing protocols for effective induction of remission. Refractory disease is generally assessed on the basis of clinical parameters, which may be unreliable, and renal biopsy, which is often not performed in a standard or timely fashion. Persisting histological inflammation in 30%–50% of patients who have attained clinical remission highlights the disparity between clinical and immunological response to therapy. The lack of an international consensus regarding what constitutes refractory lupus nephritis compounds clinician indecision regarding optimal management for these patients. Moreover, non-adherence to prescribed therapy versus primary treatment failure can be challenging to discriminate, and the time point at which non-response becomes treatment failure is unclear. In this review, we assess the key published evidence for the treatment of refractory lupus nephritis and provide practical recommendations based around the use of adjunctive therapies. These agents include rituximab and calcineurin inhibitors, with evidence consisting largely of observational or uncontrolled studies, as well as some of the biologic therapies currently under investigation through prospective clinical trials. The poor prognosis of refractory lupus nephritis demands regular review of patient response and the flexibility to switch or augment therapy.

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 role of IL-17 in systemic lupus erythematosus and its potential as a therapeutic target

INTRODUCTION

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by autoantibodies production and immune complex deposition with systemic clinical manifestations. Interleukin (IL)-17-producing cells play a crucial role in disease pathogenesis and represent an attractive therapeutic target. Areas covered: This review provides an update on the possibility of targeting IL-17 in SLE. The rational for this approach as well as currently available and future targets are discussed. Expert opinion: Although human expression studies and animal models indicate that IL-17 blocking may be a promising therapeutic strategy for SLE, direct evidence for IL-17 inhibition in SLE patients is unavailable. Biologic therapies and small-molecule drugs that target IL-17 production are required for the achievement of a favorable clinical effect in SLE patients.

Proteomic profiling of urine: implications for lupus nephritis

INTRODUCTION

Lupus nephritis (LN) is a common and significant manifestation, affecting 60% of adults and 80% of children with systemic lupus erythematosus, with up to 30% of patients progressing to end stage renal disease. There remains an unmet need for non-invasive markers of disease activity, damage, and response to therapy. In addition, non-invasive biomarkers that predict therapeutic efficacy are needed to enable cost-effective clinical trials of novel agents. Areas covered: This review examines the methodological aspects of urinary proteomics, the role of proteome profiling in identifying promising urinary biomarkers in LN, and the translation of research findings into clinically useful tools in the management of LN. Expert opinion: Targeted and unbiased proteomics have identified several promising urinary biomarkers that predict LN activity, damage (chronicity), and response to therapy. In particular, a combination of biologically plausible urinary biomarkers termed as RAIL (Renal Activity Index for Lupus) has emerged as an excellent predictor of LN activity as well as response to therapy, being able to predict efficacy within 3 months of therapy. If validated in additional large prospective studies, the RAIL biomarkers will transform the care of patients with LN, allowing for a personalized and predictive approach and improved outcomes.

Refractory lupus nephritis: When, why and how to treat

Refractory lupus nephritis indicates an inadequate response to lupus nephritis therapy. It implies persisting or worsening disease activity despite therapy, but the definition is complicated by the parameters of response, proteinuria and renal function, that do not discriminate clearly between activity and irreversible damage. Understanding the causes of refractory disease and developing treatment strategies is important because these patients are more likely to develop poor outcomes, especially end stage renal disease. This review explores current concepts and definitions of refractory disease and summarises treatment approaches that have been used in observational cohort studies and case series. We highlight the importance of optimising adherence to the prescribed immunosuppressive and supportive measures and avoidance of diagnostic delay. Treatment options include higher dose glucocorticoid, switching between cyclophosphamide and mycophenolate acid derivates, or addition of rituximab, the latter potentially in combination with belimumab. Less evidence supports extracorporeal treatment (plasma exchange or immunoadsorption), calcineurin inhibitors (cyclosporine A or tacrolimus), intravenous immunoglobulin and stem cell transplantation. Improvements in understanding what refractory disease is and how definitions can be integrated into treatment pathways has the potential to enhance lupus nephritis outcomes.

Serum Axl predicts histology-based response to induction therapy and long-term renal outcome in lupus nephritis

Axl is a receptor tyrosine kinase with important functions in immune regulation. We investigated serum levels of soluble (s)Axl in lupus nephritis (LN) in association with renal disease activity, tissue damage and treatment response. We surveyed 52 patients with International Society of Nephrology/Renal Pathology Society (ISN/RPS) class III/IV LN and 20 healthy controls. Renal biopsies were performed at the time of active LN and post-treatment. Patients were classified as clinical responders (CRs) or clinical non-responders based on the American College of Rheumatology (ACR) criteria. Improvement by ≥50% in renal activity index scores defined histological responders (HRs). sAxl levels were elevated in patients compared to controls (median: 18.9 ng/mL), both at baseline (median: 45.7; P<0.001) and post-treatment (median: 41.2 ng/mL; P<0.001). Baseline sAxl levels were higher in patients with class IV (median: 47.7 ng/mL) versus class III (median: 37.5 ng/mL) nephritis (P = 0.008), and showed moderate correlations with albuminuria (r = 0.30, P = 0.030) and creatinine (r = 0.35, P = 0.010). Baseline sAxl levels decreased in CRs (P = 0.002) and HRs (P<0.001), but not in non-responders; levels ≥36.6 ng/mL yielded a >5 times higher probability of histology-based response (odds ratio, OR: 5.5; 95% confidence interval, CI: 1.2-25.1). High post-treatment sAxl levels were associated with worsening in chronicity index scores (P = 0.025); low levels predicted favourable renal outcome (creatinine ≤88.4 μmol/L) 10 years after the baseline renal biopsy (area under the curve: 0.71; 95% CI: 0.54-0.89). In conclusion, sAxl may prove useful as a marker of renal activity, histological response to immunosuppression, and renal damage progression in LN. Persistently high sAxl levels after completion of treatment may be indicative of a need for treatment intensification.

Urinary levels of the leukocyte surface molecule CD11b associate with glomerular inflammation in lupus nephritis

Noninvasive biomarkers of disease activity are needed to monitor response to therapy and predict disease recurrence in patients with glomerulonephritis. The leukocyte surface markers integrin Mac-1 and CD16b have been implicated in the pathogenesis of lupus nephritis (LN). Mac-1 comprises a unique α subunit (CD11b) complexed with a common β2 subunit, which are released along with CD16b from specific leukocyte subsets under inflammatory conditions including glomerulonephritis. We investigated the association of urinary CD11b and CD16b with histopathological activity in 272 patients with biopsy-proven glomerular diseases, including 118 with LN. Urine CD11b and CD16b were measured via enzyme-linked immunosorbent assay. Urinary levels of both markers were increased in LN, but only urinary CD11b was correlated with the number of glomerular leukocytes and with overall histopathological activity. In a subset of patients with samples available from the time of biopsy and subsequent clinical remission of LN, urinary levels of CD11b decreased with successful glucocorticoid treatment. Receiver-operating characteristic curve analysis demonstrated that urinary CD11b was superior to CD16b, the scavenger receptor CD163, and monocyte chemotactic protein-1 for the prediction of proliferative LN. In anti-mouse nephrotoxic serum glomerulonephritis, urinary CD11b correlated with histologic damage and decreased with corticosteroid treatment. In vitro, CD11b levels were decreased on activated mouse neutrophils displaying Fcγ receptor clustering and transendothelial migration, suggesting that leukocyte activation and transmigration are required for CD11b shedding in urine. Together, our results suggest that urinary CD11b may be a useful biomarker to estimate histopathological activity, particularly glomerular leukocyte accumulation, in LN.

A Markov Multi-State model of lupus nephritis urine biomarker panel dynamics in children: Predicting changes in disease activity

BACKGROUND

A urine 'biomarker panel' comprising alpha-1-acid-glycoprotein, ceruloplasmin, transferrin and lipocalin-like-prostaglandin-D synthase performs to an 'excellent' level for lupus nephritis identification in children cross-sectionally. The aim of this study was to assess if this biomarker panel predicts lupus nephritis flare/remission longitudinally.

METHODS

The novel urinary biomarker panel was quantified by enzyme linked immunoabsorbant assay in participants of the United Kingdom Juvenile Systemic Lupus Erythematosus (UK JSLE) Cohort Study, the Einstein Lupus Cohort, and the South African Paediatric Lupus Cohort. Monocyte chemoattractant protein-1 and vascular cell adhesion molecule-1 were also quantified in view of evidence from other longitudinal studies. Serial urine samples were collected during routine care with detailed clinical and demographic data. A Markov Multi-State model of state transitions was fitted, with predictive clinical/biomarker factors assessed by a corrected Akaike Information Criterion (AICc) score (the better the model, the lower the AICc score).

RESULTS

The study included 184 longitudinal observations from 80 patients. The homogeneous multi-state Markov model of lupus nephritis activity AICc score was 147.85. Alpha-1-acid-glycoprotein and ceruloplasmin were identified to be the best predictive factors, reducing the AICc score to 139.81 and 141.40 respectively. Ceruloplasmin was associated with the active-to-inactive transition (hazard ratio 0.60 (95% confidence interval [0.39, 0.93])), and alpha-1-acid-glycoprotein with the inactive-to-active transition (hazard ratio 1.49 (95% confidence interval [1.10, 2.02])). Inputting individual alpha-1-acid-glycoprotein/ceruloplasmin values provides 3, 6 and 12 months probabilities of state transition.

CONCLUSIONS

Alpha-1-acid-glycoprotein was predictive of active lupus nephritis flare, whereas ceruloplasmin was predictive of remission. The Markov state-space model warrants testing in a prospective clinical trial of lupus nephritis biomarker led monitoring.

Pediatric lupus nephritis

Involvement of the kidneys by lupus nephritis (LN) is one of the most severe clinical manifestations seen in individuals with systemic lupus erythematosus (SLE). LN is more frequent and severe in pediatric patients and has been associated with higher morbidity and mortality rates. This narrative review aimed to describe the general aspects of LN and its particularities when affecting children and adolescents, while focusing on the disease's etiopathogenesis, clinical manifestations, renal tissue alterations, and treatment options.

Interstitial inflammation and interstitial fibrosis and tubular atrophy predict renal survival in lupus nephritis

Background

This study examines the effect of interstitial inflammation and interstitial fibrosis and tubular atrophy on renal survival in lupus nephritis.

Methods

Baseline characteristics, initial (n = 301) and repeat biopsies (n = 94) and clinical outcomes for patients with biopsy-proven lupus nephritis from 1998 to 2014 were retrospectively collected from the medical record. Clinical and morphologic variables were evaluated using a Cox proportional hazards model and multiple imputation to address missing data. Renal survival was defined as the time from initial biopsy to end-stage renal disease [estimated glomerular filtration rate (eGFR) <15 mL/min/1.73 m²], dialysis or transplant.

Results

A total of 218 patients had follow-up and Class IV had worse renal survival, especially in patients with active and chronic glomerular lesions {relative to non-IV; Class IV-A: hazard ratio [HR] 0.92 [95% confidence interval (CI) 0.41–2.04], Class IV-AC: HR 5.02 [95% CI 2.70–9.36]}. Interstitial inflammation grade [relative to interstitial inflammation <5%; interstitial inflammation 5–25%: HR 2.36 (95% CI 1.13–4.91), interstitial inflammation 25–50%: HR 3.84 (95% CI 1.53–9.62), interstitial inflammation >50%: HR 7.67 (95% CI 3.75–15.67)] and increased interstitial fibrosis and tubular atrophy (IFTA) category [relative to IFTA <5%; IFTA 5–25%: HR 3.93 (95% CI 1.58–9.75), IFTA 25–50%: HR 4.01 (95% CI 1.37–11.70), IFTA >50%: HR 13.99 (95% CI 4.91–39.83)] predicted worse renal survival among all patients and those with Class IV on initial and repeat biopsy (n = 94) in a dose-dependent manner. Interstitial inflammation grade and IFTA category were significant predictors of renal survival in a multivariable model adjusted for age, gender, race, ethnicity and serum creatinine.

Conclusions

Interstitial inflammation and IFTA independently affect renal survival and grading these lesions stratifies risk within the International Society of Nephrology and Renal Pathology Society classification of lupus nephritis.

The clinical relevance of repeat renal biopsies in the management of lupus nephritis: a South African experience

Purpose Clinically, repeat renal biopsies (RRBs) have been performed in lupus nephritis to identify changes in class, plan treatment and assist in prognostication. We set out to compare the histopathological features and outcomes of disease flare and protocol biopsy patients. Methods A retrospective descriptive study was conducted on repeat biopsies performed between January 1984 and December 2015 in lupus nephritis patients. Disease flares and protocol biopsies were compared. Results Of 614 systemic lupus erythematosus (SLE) renal biopsies, 127 (20.7%) RRBs were identified. Disease flare patients accounted for 96 (75.6%) and protocol biopsies for 31 (24.4%) of RRBs. Seventy (72.9%) disease flare patients retained their original class on repeat biopsy. When categorised as proliferative and non-proliferative histology, 83 (87.4%) of the disease flare biopsy patients remained histologically unchanged. Treatment remained unchanged in 57 (60.0%) patients following RRBs for disease flares. Response to immunosuppression in disease flare patients was poorer. Non-response was associated with increased chronicity index (OR = 1.33; 95% CI 1.01-1.76; p = 0.045). Thirty-three (36.3%) disease flare patients developed end-stage kidney disease (ESKD) in one year as compared to one (3.6%) protocol biopsy patient ( p = 0.003). ESKD in disease flare patients was associated with non-response to treatment (OR = 24.6; 95% CI 2.7-219.3; p = 0.004) on multivariate analysis. One-year mortality was 30.0% in the disease flare patients and 3.5% in protocol biopsy patients ( p = 0.018). Conclusion Repeat biopsies in disease flare patients infrequently led to histological class changes, failed to lead to change of treatment in the majority of patients, and were associated with poorer outcomes.

Histologic versus clinical remission in proliferative lupus nephritis

BACKGROUND

Treatment response in lupus nephritis (LN) is defined clinically, without consideration of renal histology. Few studies have systematically examined histologic responses to induction therapy. In LN patients who underwent protocol kidney biopsies after induction immunosuppression, we describe the renal histology of the second biopsy and correlate histologic activity and damage with short- and long-term kidney outcomes.

METHODS

Patients with suspected LN were biopsied for diagnosis (Biopsy 1), and those with proliferative LN were rebiopsied after induction (Biopsy 2). Histologic activity and damage at each biopsy were calculated as the National Institutes of Health activity and chronicity indices. Complete and partial renal responses after induction and after long-term follow-up were determined clinically.

RESULTS

One-third of patients who achieved a complete clinical response after induction had persistently high histologic activity, and 62% of patients who had complete histologic remission on rebiopsy were still clinically active. Chronic renal damage increased after induction even in complete clinical responders. Chronicity at Biopsy 2 associated with long-term kidney function and development of chronic kidney disease.

CONCLUSIONS

Early clinical and histologic outcomes are discordant in proliferative LN, and neither correlates with long-term renal outcome. The kidney accrues chronic damage rapidly and despite clinical response in LN. Preservation of kidney function may require therapeutic targeting of both chronic damage and inflammation during LN induction treatment.

Modelling clinical systemic lupus erythematosus: similarities, differences and success stories

Mouse models of SLE have been indispensable tools to study disease pathogenesis, to identify genetic susceptibility loci and targets for drug development, and for preclinical testing of novel therapeutics. Recent insights into immunological mechanisms of disease progression have boosted a revival in SLE drug development. Despite promising results in mouse studies, many novel drugs have failed to meet clinical end points. This is probably because of the complexity of the disease, which is driven by polygenic predisposition and diverse environmental factors, resulting in a heterogeneous clinical presentation. Each mouse model recapitulates limited aspects of lupus, especially in terms of the mechanism underlying disease progression. The main mouse models have been fairly successful for the evaluation of broad-acting immunosuppressants. However, the advent of targeted therapeutics calls for a selection of the most appropriate model(s) for testing and, ultimately, identification of patients who will be most likely to respond.

The value of repeat biopsy in lupus nephritis flares

Whether a repeat renal biopsy is helpful during lupus nephritis (LN) flares remains debatable. In order to analyze the clinical utility of repeat renal biopsy in this complex situation, we retrospectively reviewed our series of 54 LN patients who had one or more repeat biopsies performed only on clinical indications. Additionally, we reviewed 686 well-documented similar cases previously reported (PubMed 1990-2015).The analysis of all patients reviewed showed that histological transformations are common during a LN flare, ranging from 40% to 76% of cases. However, the prevalence of transformations and the clinical value of repeat biopsy vary when they are analyzed according to proliferative or nonproliferative lesions.The great majority of patients with class II (78% in our series and 77.5% in the literature review) progressed to a higher grade of nephritis (classes III, IV, or V), resulting in worse renal prognosis. The frequency of pathological conversion in class V is lower (33% and 43%, respectively) but equally clinically relevant, since almost all cases switched to a proliferative class. Therefore, repeat biopsy is highly advisable in patients with nonproliferative LN at baseline biopsy, because these patients have a reasonable likelihood of switch to a proliferative LN that may require more aggressive immunosuppression.In contrast, the majority of patients (82% and 73%) with proliferative classes in the reference biopsy (III, IV or mixed III/IV + V), remained into proliferative classes on repeat biopsy. Although rebiopsy in this group does not seem as necessary, it is still advisable since it will allow us to identify the 18% to 20% of patients that switch to a nonproliferative class. In addition, consistent with the reported clinical experience, repeat biopsy might also be helpful to identify selected cases with clear progression of proliferative lesions despite the initial treatment, for whom it is advisable to intensify inmunosuppression. Thus, our experience and the literature data support that repeat biopsy also brings more advantges than threats in this group.The results of the repeat biopsy led to a change in the immunosuppresive treatment in more than half of the patients on average, intensifying it in the majority of the cases, but also reducing it in 5% to 30%.

Update on Lupus Nephritis

SLE is a chronic inflammatory disease that affects the kidneys in about 50% of patients. Lupus nephritis is a major risk factor for overall morbidity and mortality in SLE, and despite potent anti-inflammatory and immunosuppressive therapies still ends in CKD or ESRD for too many patients. This review highlights recent updates in our understanding of disease epidemiology, genetics, pathogenesis, and treatment in an effort to establish a framework for lupus nephritis management that is patient-specific and oriented toward maintaining long-term kidney function in patients with lupus.

Serum soluble tumour necrosis factor receptor-2 (sTNFR2) as a biomarker of kidney tissue damage and long-term renal outcome in lupus nephritis

OBJECTIVES

We investigated the performance of soluble tumour necrosis factor receptor-2 (sTNFR2) as a biomarker of renal activity, damage, treatment response, and long-term outcome in lupus nephritis (LN).

METHOD

Serum sTNFR2 levels were assessed in 64 LN patients (52 proliferative, 12 membranous) before and after induction treatment, and in 314 non-lupus controls. In LN patients, renal biopsies were performed at baseline and post-treatment. Patients with ≥ 50% reduced proteinuria, normal or improved estimated glomerular filtration rate (eGFR) by ≥ 25%, and inactive urinary sediment were considered clinical responders (CRs). Patients with ≥ 50% improved renal activity index were considered histopathological responders (HRs). Long-term renal outcome was determined using the chronic kidney disease (CKD) stage after a median follow-up of 11.3 years.

RESULTS

sTNFR2 levels were elevated in LN patients versus controls both at baseline (p < 0.001) and post-treatment (p < 0.001), and decreased following treatment (p < 0.001). Baseline sTNFR2 correlated with Chronicity Index scores in both baseline (r = 0.34, p = 0.006) and post-treatment (r = 0.43, p < 0.001) biopsies. In membranous LN, baseline sTNFR2 levels were higher in CRs (p = 0.048) and HRs (p = 0.03) than in non-responders, and decreased only in CRs (p = 0.03). Both baseline (p = 0.02) and post-treatment (p = 0.03) sTNFR2 levels were associated with decreasing eGFR throughout long-term follow-up, and post-treatment levels were higher in patients with long-term follow-up CKD stage ≥ 3 versus 1-2 (p = 0.008).

CONCLUSIONS

Our data suggest serum sTNFR2 as a marker of kidney tissue damage and a predictor of long-term prognosis in LN, and merit further evaluation of sTNFR2 as a predictor of clinical and histopathological treatment outcomes in membranous LN.

Prognostic significance of repeat biopsy in lupus nephritis: Histopathologic worsening and a short time between biopsies is associated with significantly increased risk for end stage renal disease and death

BACKGROUND/PURPOSE

Approximately half of patients with systemic lupus erythematosus (SLE) develop lupus nephritis (LN), a major cause of morbidity and early mortality in that disease. Prolonged renal inflammation is associated with irreversible kidney damage which confers a 30% risk of end stage renal disease (ESRD), making early, aggressive treatment mandatory. Failure to achieve therapeutic response or recurrence of renal flare often prompts repeat biopsy. However, the role of repeat biopsy in determining long-term renal prognosis remains controversial. For this reason repeat biopsies are usually not utilized unless clinical evidence of refractory or recurrent disease is already present, despite known mismatches between clinical and biopsy findings. The current study quantifies the degree to which histopathologic worsening between first and second biopsies and duration between them predicts ESRD and death.

METHODS

Medical records of 141 LN patients with more than one biopsy were obtained from a single large urban medical center. Cases were attained using billing codes for diagnosis and procedures from 1/1999-1/2015. Biopsy worsening was defined as unfavorable histopathologic classification transitions and/or increased chronicity; if neither were present, the patient was defined as non-worsening. We used Cox proportional hazard models to study the relationship between ESRD and survival adjusting for covariates which included age at first biopsy, gender, race, initial biopsy class, and initial induction therapy.

RESULTS

Of 630 patients screened, 141 had more than one biopsy. Advancing chronicity was detected in 48 (34.0%) and a renal class switch to worse grade of pathology was found in 54 (38.3%). At least one of these adverse second biopsy features was reported in 79 (56.0%) patients. Five years following initial biopsy, 28 (35.4%) of those with worsening histopathology on second biopsy developed ESRD, compared to 6 (9.7%) of non-worsening patients and 10 (12.7%) of patients with worsening histopathology had died compared to 2 (3.2%) of non-worsening patients. Biopsy worsening was associated with a significantly greater 15-year risk of ESRD (Hazard Ratio 4.2, p=0.0001) and death (Hazard Ratio 4.3, p=0.022), adjusting for age, gender, race, biopsy class, and treatment. Time between first and second biopsies was <1year in 32 patients, 1-5years in 81, and >5years in 28. Over a 15-year period, those with <1year between first and second biopsies (presumably enriched for patients with early clinical signs of progression) had a significantly greater risk of ESRD (Hazard Ratio 13.7, p<0.0001) and death (Hazard Ratio 16.9, p=0.0022) after adjusting for age, gender, race, biopsy class, and treatment.

CONCLUSION

A repeat renal biopsy demonstrating worsening pathology increases the risk of ESRD and death more than four-fold compared to non-worsening patients. Given known potential mismatch between biopsy and clinical data, repeat biopsies may add important information and justify changes in treatment not considered on clinical grounds. Earlier detection of poor prognostic signs in those without early clinical deterioration might improve outcomes in enough patients to reconsider cost effectiveness of routine repeat biopsy.

Interferon (IFN)-λ is a potential mediator in lupus nephritis

OBJECTIVES

Interferon (IFN)-α is thought to be central in the pathogenesis for lupus nephritis (LN) and recent studies also indicate a role for IFNλ. Little is known about these cytokines in the context of treatment response. We studied levels of IFNα and IFNλ in patients with LN in association with clinical and histological response (HR) to treatment.

METHODS

Fifty-six patients with active LN were included. Renal biopsies were performed at baseline and after immunosuppressive therapy. Serum levels of IFNα and IFNλ were analysed at both biopsy occasions and in 163 controls. The biopsies were evaluated according to the International Society of Nephrology/Renal Pathology Society classification. Clinical response was defined according to recent definitions. HR was defined as class I, II or III/IV-C on repeat biopsies. The expression of IFNλ in renal tissue was assessed by immunohistochemistry.

RESULTS

At baseline, serum levels of both IFNα and IFNλ were higher in patients versus controls (p=0.01 and p=0.03, respectively). There was no correlation between IFNα and IFNλ. Overall, IFNα decreased after treatment (p=0.003) but IFNλ remained unchanged. However in patients with HR, IFNλ decreased (p=0.01). The highest levels of IFNλ were seen in patients with poor HR. Immunostaining of renal tissue revealed expression of IFNλ, particularly in crescent formations, inflammatory infiltrates and tubular cells.

CONCLUSIONS

The study supports a role for IFNλ in LN, both in circulation and at a tissue level. Levels of IFNα and IFNλ did not correlate and were affected differently by immunosuppression, indicating that they are differently involved in subgroups of LN. Persistent increased levels of IFNλ were associated to an unfavourable HR to treatment.

Urinary sediment suggests lupus nephritis histology

Objectives

The objective of this paper was to evaluate correlations between kidney biopsy indexes (activity and chronicity) and urinary sediment findings; the secondary objective was to find which components of urinary sediment can discriminate proliferative from other classes of lupus nephritis.

Methods

Lupus nephritis patients scheduled for a kidney biopsy were included in our study. The morning before the kidney biopsy, we took urine samples from each patient. Receiver operating characteristic (ROC) curves were plotted to determine the area under the curve (AUC) of each test for detecting proliferative lupus nephritis; a classification tree was calculated to select a set of values that best-predicted lupus nephritis classes.

Results

We included 51 patients, 36 of whom were women (70.6%). Correlations of lupus nephritis activity index with the counts in the urinary sediment of erythrocytes (isomorphic and dysmorphic), acanthocytes, and leukocytes were 0.65 ( p < 0.0001) 0.62 ( p < 0.0001) and 0.22 ( p = 0.1228), respectively. Correlations of lupus nephritis chronicity index with the counts of erythrocytes, acanthocytes, and leukocytes were 0.60 ( p ≤ 0.0001), 0.52 ( p = 0.0001) and 0.17 ( p = 0.2300), respectively. Our classification tree had an accuracy of 84.3%.

Conclusions

Evaluation of urine sediment reflects lupus nephritis histology.

The Kidney Biopsy in Lupus Nephritis: Past, Present, and Future

Since its incorporation into clinical practice in the 1950s, the percutaneous kidney biopsy has played an important role in advancing our understanding of lupus nephritis (LN). The biopsy findings have been used to classify and subgroup LN in order to obtain an accurate diagnosis and also to inform treatment decisions and predict prognosis. Several classifications schemes have been applied clinically however despite this evolution in histopathologic classification, our ability to predict treatment response and determine prognosis remains limited. In this review we will examine the evolving role of the kidney biopsy in the management of LN, including the potentially larger role the biopsy could play in the future.

A pathophysiology-based approach to the diagnosis and treatment of lupus nephritis

Lupus is no longer an unknown chameleon of medicine. Significant progress has been made on unraveling the pathogenesis of lupus and lupus nephritis, and how to treat the disease. Here we provide an update on the pathophysiology of lupus and its related kidney disease, consider areas of controversy in disease management, and discuss the unmet needs of lupus nephritis and how to address these needs. We focus on rethinking how innovative therapies for lupus nephritis should be evaluated and evolving strategies to more efficiently mitigate irreversible nephron loss in patients with lupus nephritis.

Lupus nephritis: When and how often to biopsy and what does it mean?

Renal disease is a frequent complication of SLE which can lead to significant illness and even death. Today, a baseline renal biopsy is highly recommended for all subjects with evidence of lupus nephritis. Biopsy allows the clinician to recognize and classify different forms of autoimmune lupus glomerulonephritis, and to detect other glomerular diseases with variable pathogenesis which are not directly related to autoimmune reactivity, such as lupus podocytopathy. Moreover, not only glomerular diseases, but other severe forms of renal involvement, such as tubulo-interstitial nephritis or thrombotic microangiopathy may be detected by biopsy in lupus patients. Thus, an accurate definition of the nature and severity of renal involvement is mandatory to assess the possible risk of progression and to establish an appropriate treatment. The indications to repeat biopsy are more controversial. Some physicians recommend protocol biopsies to recognize the possible transformation from one class to another one, or to identify silent progression of renal disease, others feel that good clinical monitoring is sufficient to assess prognosis and to make therapeutic decisions. At any rate, although any decision should always be taken by considering the clinical conditions of the patient, there are no doubts that repeat renal biopsy may represent a useful tool in difficult cases to evaluate the response to therapy, to modulate the intensity of treatment, and to predict the long-term renal outcome both in quiescent lupus and in flares of activity.

Antiphospholipid Antibodies in Lupus Nephritis

Lupus nephritis (LN) is a major manifestation of systemic lupus erythematosus (SLE). It remains unclear whether antiphospholipid antibodies (aPL) alter the course of LN. We thus investigated the impact of aPL on short-term and long-term renal outcomes in patients with LN. We assessed levels of aPL cross-sectionally in SLE patients diagnosed with (n = 204) or without (n = 294) LN, and prospectively in 64 patients with active biopsy-proven LN (52 proliferative, 12 membranous), before and after induction treatment (short-term outcomes). Long-term renal outcome in the prospective LN cohort was determined by the estimated glomerular filtration rate (eGFR) and the Chronic Kidney Disease (CKD) stage, after a median follow-up of 11.3 years (range: 3.3–18.8). Cross-sectional analysis revealed no association between LN and IgG/IgM anticardiolipin or anti-β₂-glycoprotein I antibodies, or lupus anticoagulant. Both aPL positivity and levels were similar in patients with active LN and non-renal SLE. Following induction treatment for LN, serum IgG/IgM aPL levels decreased in responders (p<0.005 for all), but not in non-responders. Both at active LN and post-treatment, patients with IgG, but not IgM, aPL had higher creatinine levels compared with patients without IgG aPL. Neither aPL positivity nor levels were associated with changes in eGFR from either baseline or post-treatment through long-term follow-up. Moreover, aPL positivity and levels both at baseline and post-treatment were similar in patients with a CKD stage ≥3 versus 1–2 at the last follow-up. In conclusion, neither aPL positivity nor levels were found to be associated with the occurrence of LN in SLE patients. However, IgG aPL positivity in LN patients was associated with a short-term impairment of the renal function while no effect on long-term renal outcome was observed. Furthermore, IgG and IgM aPL levels decreased following induction treatment only in responders, indicating that aPL levels are affected by immunosuppressive drugs in a response-dependent manner.

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.

Biomarkers in lupus nephritis

Lupus nephritis (LN) has significant impact on the outcome of patients with systemic lupus erythematosus (SLE). In the absence of any new breakthrough for management of LN over the last few years, using existing treatment modalities in a more effective manner is the mainstay of improving outcomes. For effectively using the drugs, disease activity needs to be assessed accurately and more objectively, which is not possible with present clinical assessment tools. Biomarkers help in accurate assessment of disease activity and enable the physician to individualize the therapy. Conventional disease activity markers have limitations which need to be addressed and research in the area of biomarker discovery in LN has immensely expanded over the last two decades as evident by the literature. Moreover, biomarkers for LN should be different from the markers of overall disease activity as LN requires significant immunosuppression, unlike other non-renal manifestations of SLE. Newly discovered biomarkers exhibit qualities pertaining to different aspects of disease activity and damage. In this review, we discuss the established as well as new biomarkers of SLE in the light of their role in LN diagnosis, follow-up, prediction of renal flare and correlation with renal histology findings.

What is damaging the kidney in lupus nephritis?

Despite marked improvements in the survival of patients with severe lupus nephritis over the past 50 years, the rate of complete clinical remission after immune suppression therapy is <50% and renal impairment still occurs in 40% of affected patients. An appreciation of the factors that lead to the development of chronic kidney disease following acute or subacute renal injury in patients with systemic lupus erythematosus is beginning to emerge. Processes that contribute to end-stage renal injury include continuing inflammation, activation of intrinsic renal cells, cell stress and hypoxia, metabolic abnormalities, aberrant tissue repair and tissue fibrosis. A deeper understanding of these processes is leading to the development of novel or adjunctive therapies that could protect the kidney from the secondary non-immune consequences of acute injury. Approaches based on a molecular-proteomic-lipidomic classification of disease should yield new information about the functional basis of disease heterogeneity so that the most effective and least toxic treatment regimens can be formulated for individual patients.

Extracellular Vesicles as Biomarkers of Systemic Lupus Erythematosus

Systemic lupus erythematosus is an autoimmune disease that predominantly affects women and typically manifests in multiple organs. The damage caused by this disorder is characterized by a chronic inflammatory state. Extracellular vesicles (EVs), including microvesicles (also known as microparticles), apoptotic bodies, and exosomes, are recognized vehicles of intercellular communication, carrying autoantigens, cytokines, and surface receptors. Therefore, the evidence of EVs and their cargo as biomarkers of autoimmune disease is rapidly expanding. This review will focus on biogenesis of extracellular vesicles, their pathophysiological roles, and their potential as biomarkers and therapeutics in inflammatory disease, especially in systemic lupus erythematosus.

Comparison and evaluation of lupus nephritis response criteria in lupus activity indices and clinical trials

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with diverse manifestations. Although the approval of new therapies includes only one agent in 50 years, a number of promising new drugs are in development. Lupus nephritis is a dreaded complication of SLE as it is associated with significant morbidity and mortality. Advancing the treatment of lupus nephritis requires well-designed clinical trials and this can be challenging in SLE. The major obstacles involve identifying the correct population of patients to enroll and ensuring that a clinically appropriate and patient-centered endpoint is being measured. In this review, we will first discuss the clinical utility of endpoints chosen to represent lupus nephritis in global disease activity scales. Second, we will review completed and active trials focused on lupus nephritis and discuss the endpoints chosen. There are many important lessons to be learned from existing assessment tools and clinical trials. Reviewing these points will help ensure that future efforts will yield meaningful disease activity measures and well-designed clinical trials to advance our understanding of lupus management.

Renal infarction due to lupus vasculopathy

In the ISN/RPS 2003 classification of lupus nephritis (LN) renal vascular lesions are not mentioned. We present a patient with postpartum lupus vasculopathy. The renal biopsy in our patient showed concentric intimal thickening with narrowed lumen. No inflammatory changes were found. It also revealed immunoglobulin and complement deposition on the wall of the arteriole. These changes indicate lupus vasculopathy. The glomeruli revealed diffuse proliferative glomerulonephritis, with wire loops and cellular crescent in one glomerulus. The patient showed improvement with immunosuppression.

Evaluation of B lymphocyte stimulator and a proliferation inducing ligand as candidate biomarkers in lupus nephritis based on clinical and histopathological outcome following induction therapy

Objectives

Lupus nephritis (LN) is a major cause of morbidity in patients with systemic lupus erythematosus (SLE). B cells have a central role in the pathogenesis of SLE. B lymphocyte stimulator (BLyS) and a proliferation inducing ligand (APRIL) are pivotal in B cell homeostasis. We aimed to investigate a potential role of serum BLyS and APRIL as biomarkers in LN, especially as predictors of treatment response.

Methods

Sixty-four patients with active LN (52 proliferative lupus nephritis (PLN); 12 membranous LN) were included. Renal biopsies were performed at baseline and after immunosuppressive treatment. Serum levels of BLyS, APRIL and autoantibodies were measured on both biopsy occasions and in 64 individually matched controls. Renal biopsies were evaluated using the International Society of Nephrology/Renal Pathology Society classification, and scored for Activity Index and Chronicity Index. Clinical responders (CR) were required to have ≥50% reduction in proteinuria, normal or improved renal function, and inactive urinary sediment. Histopathological responders (HR) were required to have ≥50% improvement in Activity Index.

Results

Baseline BLyS levels were significantly higher in LN patients compared with controls (p<0.001) and remained unchanged following induction treatment. APRIL levels were significantly higher in patients compared with controls at baseline (p=0.005) and decreased following treatment (p<0.001). Among PLN patients, APRIL levels decreased significantly only in responders (CR: p=0.009; HR: p=0.01). Baseline BLyS levels <1.5 ng/mL predicted treatment response, attaining a positive predictive value of 92% for CR with PLN at baseline.

Conclusions

BLyS and APRIL were affected differently by immunosuppression; BLyS levels remained unchanged following therapy while APRIL levels decreased. Despite unchanged BLyS levels following therapy, low baseline levels predicted both clinical and histopathological improvement. Our data support APRIL as a candidate biomarker of renal disease activity in lupus patients with proliferative glomerulonephritis and point to low baseline BLyS levels predicting treatment response in LN, especially in PLN.

Increased Th17 cells in flow cytometer-sorted CD45RO-positive memory CD4 T cells from patients with systemic lupus erythematosus

Objectives

Th17/IL-17 dysregulation is involved in human autoimmunity, and recent evidence suggests the character of long-lived differentiated memory cells in Th17. By directly measuring the peripheral blood mononuclear cells (PBMC), elevated circulating frequencies of Th17 cells have been reported in systemic lupus erythematosus (SLE) with inconsistent results regarding the correlation with disease activities. In this study, the association between circulating Th17 frequencies and disease activities or laboratory parameters was examined in flow cytometer-sorted CD45RO-positive memory CD4 T cells from SLE.

Methods

PBMC samples were obtained from 48 female lupus patients and another 48 age- and sex-matched healthy individuals. We examined frequencies of Th17 cells by sorting the purified CD4 T cells bearing the CD45RO marker, followed by intracellular IL-17A staining after in vitro activation. Frequencies of Th1 and T_Foxp3 cells were also measured by intracellular IFN-γ and Foxp3 staining, respectively. The SLE disease activity index (SLEDAI) and other laboratory parameters were further correlated with frequencies of different T cell subsets.

Results

In SLE, increased frequencies of Th17 cells were found with a positive correlation in SLEDAI. Higher frequencies of Th17 cells were found in lupus nephritis. There was a positive correlation between frequencies of Th17 cells and daily proteinuria amount.

Conclusions

By examining the sorted CD45RO-positive memory CD4 T cells, we confirm the dysregulation of Th17/IL-17 in SLE, implicating the potential to treat lupus patients with selective IL-17/IL-17R blockades.