NephCure Accelerating Cures Institute: A Multidisciplinary Consortium to Improve Care for Nephrotic Syndrome

Kidney outcomes in children with primary focal segmental glomerulosclerosis from a low- and middle- income country

BACKGROUND

Limited data exists regarding the clinical course and outcomes of children with primary focal segmental glomerulosclerosis (FSGS) from low- and middle- income countries.

METHODS

Children aged 1-18 years with biopsy-proven primary FSGS followed from January 2010-June 2023 in a tertiary-care center were enrolled and their clinical profile, histological characteristics, kidney outcomes, and predictors of adverse outcomes were determined.

RESULTS

Over 13 years, 73 (54.8% boys) children with median (IQR) age at FSGS diagnosis 6.7 (3,10) years were recruited and followed up for median 4 (2.5,8) years. FSGS-not otherwise specified (NOS) was the most common histological subtype, in 64 (87.6%) children, followed by collapsing variant in 5 (6.8%) children. At last follow-up, 43 (58.9%), 2 (2.7%) and 28 (38.3%) children were in complete remission (CR), partial remission (PR), and no remission (NR) respectively. Calcineurin inhibitors led to CR or PR in 39 (62%) children. Overall, 21 (28.7%) children progressed to chronic kidney disease (CKD) stage 2-5 (19 from NR vs. 2 from PR group; p = 0.03); with 41% of those NR at 12 months progressing to CKD 4-5 by last follow-up. On multivariable analysis, collapsing variant [adjusted HR 2.5 (95%CI 1.5, 4.17), p = 0.001] and segmental sclerosis > 25% [aHR 9.9 (95%CI 2.2, 45.2), p = 0.003] predicted kidney disease progression.

CONCLUSIONS

In children with FSGS, response to immunosuppression predicts kidney survival as evidenced by nil to lower progression to CKD 2-5 by median follow-up of 4 (2.5,8) years in children with CR and PR, compared to those with no remission at 12 months from diagnosis. Segmental sclerosis > 25% and collapsing variant predicted progression to advanced CKD.

Comparing Kidney Health Outcomes in Children, Adolescents, and Adults With Focal Segmental Glomerulosclerosis

Importance

Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage kidney disease (ESKD) across the lifespan. While 10% to 15% of children and 3% of adults who develop ESKD have FSGS, it remains uncertain whether the natural history differs in pediatric vs adult patients, and this uncertainty contributes to the exclusion of children and adolescents in clinical trials.

Objective

To examine whether there are differences in the kidney health outcomes among children, adolescents, and adults with FSGS.

Design, Setting, and Participants

This cohort study used pooled and parallel analyses, completed July 5, 2022, from 3 complimentary data sources: (1) Nephrotic Syndrome Rare Disease Clinical Research Network (NEPTUNE); (2) FSGS clinical trial (FSGS-CT); and (3) Kidney Research Network (KRN). NEPTUNE is a multicenter US/Canada cohort study; FSGS-CT is a multicenter US/Canada clinical trial; and KRN is a multicenter US electronic health record-based registry from academic and community nephrology practices. NEPTUNE included 166 patients with incident FSGS enrolled at first kidney biopsy; FSGS-CT included 132 patients with steroid-resistant FSGS randomized to cyclosporine vs dexamethasone with mycophenolate; and KRN included 184 patients with prevalent FSGS. Data were collected from November 2004 to October 2019 and analyzed from October 2020 to July 2022.

Exposures

Age: children (age <13 years) vs adolescents (13-17 years) vs adults (≥18 years). Covariates of interest included sex, disease duration, APOL1 genotype, urine protein-to-creatinine ratio, estimated glomerular filtration rate (eGFR), edema, serum albumin, and immunosuppressive therapy.

Main Outcomes and Measures

ESKD, composite outcome of ESKD or 40% decline in eGFR, and complete and/or partial remission of proteinuria.

Results

The study included 127 (26%) children, 102 (21%) adolescents, and 253 (52%) adults, including 215 (45%) female participants and 138 (29%) who identified as Black, 98 (20%) who identified as Hispanic, and 275 (57%) who identified as White. Overall, the median time to ESKD was 11.9 years (IQR, 5.2-19.1 years). There was no difference in ESKD risk among children vs adults (hazard ratio [HR], 0.67; 95% CI, 0.43-1.03) or adolescents vs adults (HR, 0.85; 95% CI, 0.52-1.36). The median time to the composite end point was 5.7 years (IQR 1.6-15.2 years), with hazard ratio estimates for children vs adults of 1.12 (95% CI, 0.83-1.52) and adolescents vs adults of 1.06 (95% CI, 0.75-1.50).

Conclusions and Relevance

In this study, the association of FSGS with kidney survival and functional outcomes was comparable at all ages.

Primary Nephrotic Syndrome and Risks of ESKD, Cardiovascular Events, and Death: The Kaiser Permanente Nephrotic Syndrome Study

BACKGROUND

Little population-based data exist about adults with primary nephrotic syndrome.

METHODS

To evaluate kidney, cardiovascular, and mortality outcomes in adults with primary nephrotic syndrome, we identified adults within an integrated health care delivery system (Kaiser Permanente Northern California) with nephrotic-range proteinuria or diagnosed nephrotic syndrome between 1996 and 2012. Nephrologists reviewed medical records for clinical presentation, laboratory findings, and biopsy results to confirm primary nephrotic syndrome and assigned etiology. We identified a 1:100 time-matched cohort of adults without diabetes, diagnosed nephrotic syndrome, or proteinuria as controls to compare rates of ESKD, cardiovascular outcomes, and death through 2014, using multivariable Cox regression.

RESULTS

We confirmed 907 patients with primary nephrotic syndrome (655 definite and 252 presumed patients with FSGS [40%], membranous nephropathy [40%], and minimal change disease [20%]). Mean age was 49 years; 43% were women. Adults with primary nephrotic syndrome had higher adjusted rates of ESKD (adjusted hazard ratio [aHR], 19.63; 95% confidence interval [95% CI], 12.76 to 30.20), acute coronary syndrome (aHR, 2.58; 95% CI, 1.89 to 3.52), heart failure (aHR, 3.01; 95% CI, 2.16 to 4.19), ischemic stroke (aHR, 1.80; 95% CI, 1.06 to 3.05), venous thromboembolism (aHR, 2.56; 95% CI, 1.35 to 4.85), and death (aHR, 1.34; 95% CI, 1.09 to 1.64) versus controls. Excess ESKD risk was significantly higher for FSGS and membranous nephropathy than for presumed minimal change disease. The three etiologies of primary nephrotic syndrome did not differ significantly in terms of cardiovascular outcomes and death.

CONCLUSIONS

Adults with primary nephrotic syndrome experience higher adjusted rates of ESKD, cardiovascular outcomes, and death, with significant variation by underlying etiology in the risk for developing ESKD.

Association between Psychiatric Disorders and Glomerular Disease

Introduction

Patients with chronic health conditions, particularly chronic kidney disease, are at heightened risk for psychiatric disorders; yet, there are limited data on those with primary glomerular disease.

Methods

This study included patients with glomerular disease enrolled in the kidney research network multisite patient registry. Registry data include encounter, diagnoses, medication, laboratory, and vital signs data extracted from participants' electronic health records. ICD-9/10 diagnosis codes were used to identify a subset of psychiatric disorders focused on anxiety, mood, and behavioral disorders. Time-varying Cox proportional hazard models were used to analyze time from the onset of kidney disease to diagnosis of psychiatric disorder. Adjusted models retained significant covariates from the full list of potential confounders, including age, sex, race, ethnicity, time-varying treatment, the estimated glomerular filtration rate, and proteinuria (urine protein-to-creatinine ratio [UPCR]). Analogous models examined diagnosis of psychiatric disorder as a predictor of time to end-stage kidney disease (ESKD).

Results

Data were available for 950 participants, with a median of 58 months of follow-up. 110 (12%) participants were diagnosed with psychiatric disorder during the follow-up. The estimated rate of psychiatric diagnosis after kidney disease was 14.7 cases per 1,000 person-years and was highest among those of adolescent age at the time of kidney disease diagnosis. Adjusted analyses found adolescent age (vs. adult, hazard ratio [HR] = 3.11, 95% confidence interval [CI] 1.87-5.17) and Asian race (vs. white, HR = 0.34, 95% CI 0.16-0.71) were associated with psychiatric diagnosis. A higher UPCR per 1 log unit (HR 1.13, 95% CI 1.01-1.27) and a higher total number of oral medications were associated with psychiatric disorder (p < 0.001). Psychiatric diagnosis was also associated with progression to ESKD (HR = 2.45, 95% CI 1.53-3.92) in adjusted models.

Discussion/Conclusion

Psychiatric disorders were documented in approximately one-eighth of patients with glomerular disease and correlated with clinical disease characteristics such as age, race, proteinuria, and oral medication burden. These findings suggest mental health screening is warranted in patients of all ages with glomerular disease.

The Development and Use of an EHR-Linked Database for Glomerular Disease Research and Quality Initiatives

Background and Objective

The use of electronic health record (EHR) data can facilitate efficient research and quality initiatives. The imprecision of ICD-10 codes for kidney diagnoses has been an obstacle to discrete data-defined diagnoses in the EHR. This manuscript describes the Kidney Research Network (KRN) registry and database that provide an example of a prospective, real-world data glomerular disease registry for research and quality initiatives.

Methods

KRN is a multicenter collaboration of patients, physicians, and scientists across diverse health-care settings with a focus on improving treatment options and outcomes for patients with glomerular disease. The registry and data warehouse amasses retrospective and prospective data including EHR, active research study, completed clinical trials, patient reported outcomes, and other relevant data. Following consent, participating sites enter the patient into KRN and provide a physician-confirmed primary kidney diagnosis. Kidney biopsy reports are redacted and uploaded. Site programmers extract local EHR data including demographics, insurance type, zip code, diagnoses, encounters, laboratories, procedures, medications, dialysis/transplant status, vitals, and vital status monthly. Participating sites transform data to conform to a common data model prior to submitting to the Data Analysis and Coordinating Center (DACC). The DACC stores and reviews each site's EHR data for quality before loading into the KRN database.

Results

As of January 2021, 1,192 patients have enrolled in the registry. The database has been utilized for research, clinical trial design, clinical trial end point validation, and supported quality initiatives. The data also support a dashboard allowing enrolling sites to assist with clinical trial enrollment and population health initiatives.

Conclusion

A multicenter registry using EHR data, following physician- and biopsy-confirmed glomerular disease diagnosis, can be established and used effectively for research and quality initiatives. This design provides an example which may be readily replicated for other rare or common disease endeavors.

Vascular Endothelial Growth Factor (VEGF) and Neopterin Levels in Children with Steroid-sensitive and Steroid-resistant Nephrotic Syndrome

BACKGROUND

The most common glomerular disease in children is nephrotic syndrome. Steroid-resistant nephrotic syndrome tends to have a worse disease course, which bears a significant risk of chronic kidney disease in children.

OBJECTIVE

To compare VEGF and neopterin levels between children with steroid-sensitive nephrotic syndrome (SSNS), steroid-resistant nephrotic syndrome (SRNS), and also healthy (control) children.

METHODS

This cross-sectional study was conducted at H. Adam Malik General Hospital, Indonesia from January to December 2018. There were 160 children aged 1 to 8 years with confirmed nephrotic syndrome and without end-stage renal disease and systemic diseases, divided into SSNS, SRNS, and control groups. Data regarding age, gender, urine albumin creatinine ratio (UACR), serum albumin, total cholesterol, urea, creatinine, VEGF, and neopterin levels were collected. A p-value of less than 0.05 is considered statistically significant.

RESULTS

There were no differences between groups in gender (p = 0.269) and age (p = 0.375), but there was significant difference of UACR, albumin level, total cholesterol level, and VEGF level between groups, (all p< 0.001). There was a moderate positive correlation between VEGF level and UACR (r(158) = 0.439, p< 0.001) and a moderate negative correlation between neopterin level and albumin level (r(158)= -0.312, p = 0.005).

CONCLUSION

There were no differences in serum VEGF and neopterin levels between steroid-sensitive and steroid-resistant nephrotic syndrome groups. Serum VEGF level was positively correlated with UACR while serum neopterin level was negatively correlated with serum albumin level.

The Use of Patient-Reported Outcome Measures in Rare Diseases and Implications for Health Technology Assessment

Background

Patient-reported outcome measures (PROMs) are used in health technology assessment (HTA) to measure patient experiences with disease and treatment, allowing a deeper understanding of treatment impact beyond clinical endpoints. Developing and administering PROMs for rare diseases poses unique challenges because of small patient populations, disease heterogeneity, lack of natural history knowledge, and short-term studies.

Objective

This research aims to identify key factors to consider when using different types of PROMs in HTA for rare disease treatments (RDTs).

Methods

A scoping review of scientific and grey literature was conducted, with no date or publication type restrictions. Information on the advantages of and the challenges and potential solutions when using different types of PROMs for RDTs, including psychometric properties, was extracted and synthesized.

Results

Of 79 records from PubMed, 32 were included, plus 12 records from the grey literature. PROMs for rare diseases face potential data collection and psychometric challenges resulting from small patient populations and disease heterogeneity. Generic PROMs are comparable across diseases but not sensitive to disease specificities. Disease-specific instruments are sensitive but do not exist for many rare diseases and rarely provide the utility values required by some HTA bodies. Creating new PROMs is time and resource intensive. Potential solutions include pooling data (multi-site/international data collection), using computer-assisted technology, or using generic and disease-specific PROMs in a complementary way.

Conclusions

PROMs are relevant in HTA for RDTs but pose a number of difficulties. A deeper understanding of the potential advantages of and the challenges and potential solutions for each can help manage these difficulties.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40271-020-00493-w.

Time to Initiation of Antihypertensive Therapy After Onset of Elevated Blood Pressure in Patients With Primary Proteinuric Kidney Disease

Rationale & Objective

The objective of the study was to estimate the prevalence of hypertension in patients with proteinuric kidney disease and evaluate blood pressure (BP) control.

Study Design

Retrospective cohort study.

Setting & Participants

Data from adults and children with proteinuric kidney disease enrolled in the multicenter Kidney Research Network Registry were used for this study.

Exposure

Proteinuric kidney disease.

Outcomes

Hypertension and BP control.

Analytical Approach

Patients with white-coat hypertension were excluded. Patients were censored at end-stage kidney disease onset. Patients were defined as hypertensive either by hypertension diagnosis code, having 2 or more encounters with elevated BPs, or treatment with antihypertensive therapy excluding renin-angiotensin-aldosterone system blockade. Elevated BP was defined as greater than 95th percentile for children and >140/90 mm Hg in adults. Sustained BP control was defined as 2 or more consecutive encounters with BPs lower than 95th percentile for children and <140/90 mm Hg for adults. Kaplan-Meier and Cox proportional hazards analyses were used to evaluate the time to initiation of antihypertensive therapy.

Results

842 patients, 69% adults and 31% children, with a total observation period of 6,722 patient-years were included in the analysis. 644 (76%) had hypertension during observation. There was no difference in the prevalence of hypertension between children and adults (74% vs 78%; P = 0.3). Hypertension was most common among those of African American race compared with other races (90% vs 72%-75%; P = 0.003). 504 (78%) patients with hypertension achieved BP control but only 51% achieved control within 1 year. 140 (22%) patients with hypertension never achieved BP control during a median of 41 (IQR, 24-73) months of observation.

Limitations

Differing BP control goals that may lead to overestimation of the controlled patient population.

Conclusions

Hypertension affects most patients with proteinuric kidney disease regardless of age. Time to BP control exceeded 1 year in 50% of patients with hypertension and 22% did not demonstrate control. This study highlights the need to address hypertension early and completely in disease management of patients with proteinuric kidney disease.

Steroid-Associated Side Effects in Patients With Primary Proteinuric Kidney Disease

Introduction

The goal of this study was to assess the occurrence of steroid-associated adverse events (SAAE) in patients with primary proteinuric kidney disease.

Methods

The Kidney Research Network Registry consists of children and adults with primary proteinuric kidney disease. SAAEs of interest were hypertension, hyperglycemia and diabetes, overweight and obesity, short stature, ophthalmologic complications, bone disorders, infections, and psychosis. Events were identified using International Classification of Diseases, Ninth Revision/Tenth Revision codes, blood pressures, growth parameters, laboratory values, and medications. Poisson generalized estimating equations tested the association between steroid onset and dose on SAAE risk.

Results

A total of 884 participants were included in the analysis; 534 (60%) were treated with steroids. Of these, 62% had at least one SAAE. The frequency of any SAAE after initiation of steroids was 293 per 1000 person-years. The most common SAAEs were hypertension (173.7 per 1000 person-years), diabetes (78.7 per 1000 person-years), obesity (66.8 per 1000 person-years), and infections (46.1 per 1000 person-years). After adjustment for demographics, duration of kidney disease, estimated glomerular filtration rate (eGFR), proteinuria, and other therapies, steroid exposure was associated with a 40% increase in risk of any SAAE (Relative risk [RR]: 1.4; 95% confidence interval [CI]: 1.3–1.6). A 1-mg/kg per day increase in steroid dose was associated with a 2.5-fold increase in risk of any SAAE.

Conclusion

Most patients with primary proteinuric kidney disease treated with steroids experienced at least one SAAE. Steroid therapy increased risk of hypertension, diabetes, weight gain, short stature, fractures, and infections after adjusting for disease-related factors. This study highlights the importance of surveillance and management of SAAE and provides rationale for the development of steroid minimization protocols.