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

Managing Lupus Nephritis in Children and Adolescents

Lupus nephritis is an important manifestation of systemic lupus erythematosus, which leads to chronic kidney disease, kidney failure, and can result in mortality. About 35%-60% of children with systemic lupus erythematosus develop kidney involvement. Over the past few decades, the outcome of patients with lupus nephritis has improved significantly with advances in immunosuppressive therapies and clinical management. Nonetheless, there is a paucity of high-level evidence to guide the management of childhood-onset lupus nephritis, because of the relatively small number of patients at each centre and also because children and adolescents are often excluded from clinical trials. Children and adults differ in more ways than just size, and there are remarkable differences between childhood- and adult-onset lupus nephritis in terms of disease severity, treatment efficacy, tolerance to medications and most importantly, psychosocial perspective. In this article, we review the 'art and science' of managing childhood-onset lupus nephritis, which has evolved in recent years, and highlight special considerations in this specific patient population.

Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

Performance of Clinical and Biochemical Parameters in Identifying Renal Histopathology and Predictors of One-Year Renal Outcome in Lupus Nephritis-A Single Centre Study from India

Objectives: To assess the performance of clinical and biochemical parameters in identifying renal histopathology. To assess the performance of a combination of demographic, clinical, serological and histopathological parameters in determining renal response at one year. Methods: Data of biopsy-proven (ISN/RPS—2003 criteria) Lupus Nephritis (LN) were extracted from the institute database. Demographic, clinical and biochemical parameters at the time of biopsy were noted, and their associations with histopathological class, activity and chronicity scores were evaluated. Follow-up data at one year were collected. Complete, partial or no response (CR, PR, NR) for renal outcomes at one year and the predictors of NR were assessed. Results: Out of the 333 renal biopsies, 240 (71.8%) were Class III/IV. More patients with Class III/IV LN had hypertension (52.1%) and low eGFR (p < 0.001). Among Class III/IV, AS correlated weakly with UPCR (r = 0.31, p < 0.01), eGFR (r = −0.172; p < 0.01) and CS with eGFR (r = −0.212; p < 0.01). The presence of either hypertension, UPCR > 0.5 g/day, active urinary sediments or serum creatinine >1.3 g/dL had a sensitivity of >96% and specificity of <9% in detecting proliferative LN, crescents, interstitial inflammation and chronicity. NR was higher in males (aOR:3.9, 95% CI:1.4−11.0, p < 0.001), those with abnormal baseline creatinine (aOR: 1.9, 95% CI: 1.1−3.2, p < 0.001), higher renal SLEDAI (p < 0.05), higher AS, CS (p < 0.001) and interstitial inflammation (p < 0.005). In the binary logistic regression, the combination of male sex, baseline creatinine, UPCR and CS performed best in predicting NR (AUC: 0.762; 95% CI: 0.684−0.840, p < 0.001). Conclusions: Clinical and biochemical parameters alone have a poor specificity in identifying renal histopathology. A combination of demographic, clinical and histopathology parameters can better predict renal outcomes at one year.

Working Towards a Treat-to-Target Protocol in Juvenile Proliferative Lupus Nephritis - A Survey of Pediatric Rheumatologists and Nephrologists in Germany and Austria

BACKGROUND

To describe treatment practices for juvenile proliferative lupus nephritis (LN) class III and IV of pediatric rheumatologists and nephrologists in Germany and Austria in preparation for a treat-to-target treatment protocol in LN.

METHODS

Survey study by members of the Society for Pediatric and Adolescent Rheumatology (GKJR) and the German Society for Pediatric Nephrology (GPN) on diagnostics and (concomitant) therapy of LN.

RESULTS

Fifty-eight physicians completed the survey. Overall, there was a considerable heterogeneity regarding the suggested diagnostics and management of juvenile proliferative LN. Increased urinary protein excretion, either assessed by 24 h urine collection or spot urine (protein-creatinine ratio), and reduced estimated glomerular filtration rate were specified as important parameters for indication of kidney biopsy to diagnose proliferative LN and monitoring of therapy. Corticosteroids were generally proposed for induction and maintenance therapy, most often in conjunction with either mycophenolate mofetil (MMF) or cyclophosphamide (CP) as steroid-sparing immunosuppressants. MMF was clearly preferred over CP for induction therapy of LN class III, whereas CP and MMF were equally proposed for LN class IV. MMF was most often recommended for maintenance therapy in conjunction with oral corticosteroids and continued for at least 3 years and 1 year, respectively, after remission. Hydroxychloroquine was widely accepted as a concomitant measure followed by renin-angiotensin system inhibitors in cases of arterial hypertension and/or proteinuria.

CONCLUSION

The majority of pediatric rheumatologists and nephrologists in Germany and Austria propose the use of corticosteroids, most often in combination with either MMF or CP, for treatment of proliferative LN in children. The considerable heterogeneity of responses supports the need for a treat-to-target protocol for juvenile proliferative LN between pediatric rheumatologists and nephrologists.

Using a Multi-Institutional Pediatric Learning Health System to Identify Systemic Lupus Erythematosus and Lupus Nephritis: Development and Validation of Computable Phenotypes

BACKGROUND AND OBJECTIVES

Performing adequately powered clinical trials in pediatric diseases, such as SLE, is challenging. Improved recruitment strategies are needed for identifying patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Electronic health record algorithms were developed and tested to identify children with SLE both with and without lupus nephritis. We used single-center electronic health record data to develop computable phenotypes composed of diagnosis, medication, procedure, and utilization codes. These were evaluated iteratively against a manually assembled database of patients with SLE. The highest-performing phenotypes were then evaluated across institutions in PEDSnet, a national health care systems network of >6.7 million children. Reviewers blinded to case status used standardized forms to review random samples of cases (n=350) and noncases (n=350).

RESULTS

Final algorithms consisted of both utilization and diagnostic criteria. For both, utilization criteria included two or more in-person visits with nephrology or rheumatology and ≥60 days follow-up. SLE diagnostic criteria included absence of neonatal lupus, one or more hydroxychloroquine exposures, and either three or more qualifying diagnosis codes separated by ≥30 days or one or more diagnosis codes and one or more kidney biopsy procedure codes. Sensitivity was 100% (95% confidence interval [95% CI], 99 to 100), specificity was 92% (95% CI, 88 to 94), positive predictive value was 91% (95% CI, 87 to 94), and negative predictive value was 100% (95% CI, 99 to 100). Lupus nephritis diagnostic criteria included either three or more qualifying lupus nephritis diagnosis codes (or SLE codes on the same day as glomerular/kidney codes) separated by ≥30 days or one or more SLE diagnosis codes and one or more kidney biopsy procedure codes. Sensitivity was 90% (95% CI, 85 to 94), specificity was 93% (95% CI, 89 to 97), positive predictive value was 94% (95% CI, 89 to 97), and negative predictive value was 90% (95% CI, 84 to 94). Algorithms identified 1508 children with SLE at PEDSnet institutions (537 with lupus nephritis), 809 of whom were seen in the past 12 months.

CONCLUSIONS

Electronic health record-based algorithms for SLE and lupus nephritis demonstrated excellent classification accuracy across PEDSnet institutions.

Research priorities in childhood-onset lupus: results of a multidisciplinary prioritization exercise

BACKGROUND

Childhood-onset systemic erythematosus lupus (cSLE) is characterized by more severe disease, widespread organ involvement and higher mortality compared to adult-onset SLE. However, cSLE is largely underfunded to carry out necessary research to advance the field. Few commonly used SLE medications have been studied in children, and important knowledge gaps exist concerning epidemiology, genetics, pathophysiology and optimal treatments for cSLE.

METHODS

In order to assess highest cSLE research priority areas, the Lupus Foundation of America (LFA) and Childhood Arthritis and Rheumatology Research Alliance (CARRA) administered a cSLE research prioritization survey to pediatric rheumatologists, dermatologists and nephrologists with expertise in lupus. Members of LFA and CARRA's SLE Committee identified a list of cSLE research domains and developed a 17-item tiered, web-based survey asking respondents to categorize the research domains into high, medium, or low priority areas. For domains identified as high priority, respondents ranked research topics within that category. For example, for the domain of nephritis, respondents ranked importance of: epidemiology, biomarkers, long-term outcomes, quality improvement, etc. The survey was distributed to members of CARRA, Midwestern Pediatric Nephrology Consortium (MWPNC) and Pediatric Dermatology Research Alliance (PeDRA) Connective Tissue Disease group.

RESULTS

The overall response rate was 256/752 (34%). The highest prioritized research domains were: nephritis, clinical trials, biomarkers, neuropsychiatric disease and refractory skin disease. Notably, nephritis, clinical trials and biomarkers were ranked in the top five by all groups. Within each research domain, all groups showed agreement in identifying the following as important focus areas: determining best treatments, biomarkers/pathophysiology, drug discovery/novel treatments, understanding long term outcomes, and refining provider reported quality measures.

CONCLUSION

This survey identified the highest cSLE research priorities among leading rheumatology, dermatology and nephrology clinicians and investigators engaged in care of children with lupus. There is a strong need for multidisciplinary collaboration moving forward, which was indicated as highly important among stakeholders involved in the survey. These survey results should be used as a roadmap to guide funding and specific research programs in cSLE to address urgent, unmet needs among this population.

Practice-based differences in paediatric discoid lupus erythematosus

BACKGROUND

Children with discoid lupus erythematosus (DLE) are at risk for disfigurement and progression to systemic lupus erythematosus (SLE). Consensus is lacking regarding optimal care for children with DLE.

OBJECTIVES

The aim of this study was to compare practice patterns among paediatric dermatologists/rheumatologists treating paediatric DLE.

METHODS

An online survey was sent to 292 paediatric rheumatologists in the Childhood Arthritis and Rheumatology Research Alliance and 200 paediatric dermatologists in the Pediatric Dermatology Research Alliance. Consensus was defined as ≥ 70% agreement.

RESULTS

Survey response rates were 38% (76 of 200) for dermatology and 21% (60 of 292) for rheumatology. Both specialties agreed that screening labs should include complete blood counts with differential, urinalysis, complement levels, erythrocyte sedimentation rate, antinuclear antibody and other autoantibodies, hepatic function and renal function/electrolytes. Both specialties agreed that arthritis or nephritis should prompt intensified evaluation for SLE. No other patient features achieved consensus as disease-modifying risk factors. Hydroxychloroquine was agreed upon as first-line systemic therapy, but consensus was lacking for second- or third-line treatment.

CONCLUSIONS

We found few areas of consensus and significant practice differences between paediatric dermatologists and rheumatologists treating DLE. Knowledge gaps include risk factors for SLE, optimal screening and treatment of refractory skin disease.

Urine biomarkers of chronic kidney damage and renal functional decline in childhood-onset systemic lupus erythematosus

OBJECTIVES

To delineate urine biomarkers that reflect kidney structural damage and predict renal functional decline in pediatric lupus nephritis (LN).

METHODS

In this prospective study, we evaluated kidney biopsies and urine samples of 89 patients with pediatric LN. Urinary levels of 10 biomarkers [adiponectin, ceruloplasmin, kidney injury molecule-1, monocyte chemotactic protein-1, neutrophil gelatinase-associated lipocalin, osteopontin, transforming growth factor-ß (TGFß), vitamin-D binding protein, liver fatty acid binding protein (LFABP), and transferrin] were measured. Regression analysis was used to identify individual and combinations of biomarkers that determine LN damage status [NIH-chronicity index (NIH-CI) score ≤ 1 vs. ≥ 2] both individually and in combination, and biomarker levels were compared for patients with vs. without renal functional decline, i.e., a 20% reduction of the glomerular filtration rate (GFR) within 12 months of a kidney biopsy.

RESULTS

Adiponectin, LFABP, and osteopontin levels differed significantly with select histological damage features considered in the NIH-CI. The GFR was associated with NIH-CI scores [Pearson correlation coefficient (r) = - 0.49; p < 0.0001] but not proteinuria (r = 0.20; p > 0.05). Similar to the GFR [area under the ROC curve (AUC) = 0.72; p < 0.01], combinations of osteopontin and adiponectin levels showed moderate accuracy [AUC = 0.75; p = 0.003] in discriminating patients by LN damage status. Renal functional decline occurred more commonly with continuously higher levels of the biomarkers, especially of TGFß, transferrin, and LFABP.

CONCLUSION

In combination, urinary levels of adiponectin and osteopontin predict chronic LN damage with similar accuracy as the GFR. Ongoing LN activity as reflected by high levels of LN activity biomarkers heralds renal functional decline.

KEY MESSAGES

• Levels of osteopontin and adiponectin measured at the time of kidney biopsy are good predictors of histological damage with lupus nephritis. • Only about 20% of children with substantial kidney damage from lupus nephritis will have an abnormally low urine creatinine clearance. • Continuously high levels of biomarkers reflecting lupus nephritis activity are risk factors of declining renal function.

Approach to Membranous Lupus Nephritis: A Survey of Pediatric Nephrologists and Pediatric Rheumatologists

OBJECTIVE

To describe treatment practices for childhood pure membranous lupus nephritis (MLN).

METHODS

Survey study of Childhood Arthritis and Rheumatology Research Alliance and American Society of Pediatric Nephrology members.

RESULTS

There were 117 respondents who completed the survey (60 pediatric nephrologists, 57 pediatric rheumatologists). Steroids and nonsteroid immunosuppression (NSI) were routinely used by the majority for MLN. Mycophenolate mofetil was the favored initial NSI. Nephrologists used steroids (60% vs 93%) and NSI (53% vs 87%) less often than did rheumatologists for MLN without nephrotic syndrome (NS).

CONCLUSION

Pediatric rheumatologists and nephrologists both recommend steroids and NSI for children with MLN, with or without NS.

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%.

Treatment of pediatric-onset lupus nephritis: a proposal of optimal therapy

Lupus nephritis (LN) is one of the major clinical manifestations of systemic lupus erythematosus (SLE) which occurs frequently in the early stages of pediatric-onset cases. Since SLE is a chronic disease associated with frequent disease flares and effective and safe maintenance therapy is required for achieving a favorable outcome, optimal treatment for LN in pubertal patients is a great challenge that remains to be overcome. Although its etiology remains unclear, it has been reported that the innate and adaptive immune systems have been reported to play an important role in the pathogenesis of SLE. However, studies of drugs that have been useful in controlling inflammatory pathways mediated by the innate and adaptive immune systems are now underway. In clinical practice, recent advances in the management of LN, together with earlier renal biopsy and selective use of aggressive immunosuppressive therapy, have contributed to a favorable outcome in children and adolescents with LN. However, the balance of the efficacy of treatment in terms of long-term prognosis and its adverse effects should be weighed in determining the treatment strategy.

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.