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.

Proteinuria Reduction and Kidney Survival in Focal Segmental Glomerulosclerosis.

RATIONALE & OBJECTIVE: Remission of proteinuria has been shown to be associated with lower rates of kidney disease progression among people with focal segmental glomerulosclerosis (FSGS). The goal of this study was to evaluate whether reductions in proteinuria after treatment are associated with greater kidney survival. STUDY DESIGN: Cohort analysis of clinical trial participants. SETTING & PARTICIPANTS: Patients with steroid-resistant FSGS enrolled in a randomized treatment trial that compared cyclosporine with mycophenolate mofetil plus dexamethasone. PREDICTORS: Reduction in proteinuria measured during 26 weeks after initiating treatment. OUTCOMES: Repeated assessments of estimated glomerular filtration rate (eGFR) and time to a composite outcome of kidney failure or death assessed between 26 weeks and 54 months after randomization. ANALYTICAL APPROACH: Multivariable linear mixed-effects models with participant-specific slope and intercept to estimate the association of change in proteinuria over 26 weeks while receiving treatment with the subsequent slope of change in eGFR. Multivariable time-varying Cox proportional hazards models were used to estimate the association of changes in proteinuria with time to the composite outcome. RESULTS: 138 of 192 trial participants were included. Changes in proteinuria over 26 weeks were significantly related to eGFR slope. A 1-unit reduction in log-transformed urinary protein-creatinine ratio was associated with a 3.90mL/min/1.73m2 per year increase in eGFR (95% CI, 2.01-5.79). This difference remained significant after adjusting for complete remission. There was an analogous relationship between time-varying proteinuria and time to the composite outcome: the HR per 1-unit reduction in log-transformed urinary protein-creatinine ratio was 0.23 (95% CI, 0.12-0.44). LIMITATIONS: Limited to individuals with steroid-resistant FSGS followed up for a maximum of 5 years. CONCLUSIONS: These findings provide evidence for the benefit of urinary protein reduction in FSGS. Reductions in proteinuria warrant further evaluation as a potential surrogate for preservation of kidney function that may inform the design of future clinical trials.

Tolerance in Solid-Organ Transplant.

Immunotolerance, which is nonimmunologic reactivity to specific tissue, was demonstrated in animals in the 1950s. However, despite assiduous efforts, it has not been reproduced in human solid-organ transplant to date. Fortuitously, clinical operational tolerance, which is stable graft function for > 1 year with no immunosuppression, has been demonstrated, primarily in a few nonadherent recipients of kidney and liver transplant. Vigorous efforts to identify a biomarker to distinguish recipients with clinical operational tolerance from nontolerant recipients have so far not been successful. However, weaning of immunosuppression in stable pediatric and adult liver transplant recipients has been successful in 60% and 20% of recipients. In kidney transplant recipients, clinical operational tolerance has been induced by combined kidney and hematopoietic cell transplant to induce chimerism and subsequent weaning of immunosuppression. Recently, the ex vivo expansion of autologous regulatory T cells with subsequent infusion has facilitated weaning of immuno suppression in liver transplant recipients. Protocols have been initiated to expand the use of regulatory T cells to kidney transplant recipients. These new methodologies have the potential to induce clinical operational tolerance in all recipients of a solid-organ transplant in the future, thus avoiding the long-term consequences of continued dependence on immunosuppressive medications for stable graft function.

Kidney retransplantation in children following rejection and recurrent disease.

Retransplantation accounts for approximately 15 % of the annual transplants performed in the USA, and in the recent International Collaborative Transplant Study report on pediatric patients 15.2 % of the 9209 patients included in the report were retransplant recipients. Although the significant advances in clinical management and newer immunosuppressive agents have had a significant impact on improving short-term allograft function, it is apparent that long-term allograft function remains suboptimal. Therefore, it is likely that the majority of pediatric renal allograft recipients will require one or more retransplants during their lifetime. Unfortunately, a second or subsequent graft in pediatric recipients has inferior long-term graft survival rates compared to initial grafts, with decreasing rates with each subsequent graft. Multiple issues influence the outcome of retransplantation, with the most significant being the cause of the prior transplant failure. Non-adherence-associated graft loss poses unresolved ethical issues that may impact access to retransplantation. Graft nephrectomy prior to retransplantation may benefit selected patients, but the impact of an in situ failed graft on the development of panel-reactive antibodies remains to be definitively determined. It is important that these and other factors discussed in this review be taken into consideration during the counseling of families on the optimal approach for their child who requires a retransplant.

Height at First RRT and Mortality in Children.

BACKGROUND AND OBJECTIVES: Poor linear growth is common in children with CKD and has been associated with higher mortality. However, recent data in adult dialysis patients have suggested a higher risk of death in persons of tall stature. In this study, we aimed to examine the risk of all-cause and cause-specific mortality in children at both extremes of height at the time of first RRT. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Using the US Renal Data System, we performed a retrospective analysis of 13,218 children aged 2-19 years, who received their first RRT (dialysis or transplant) during 1995-2011. We used adjusted Cox models to examine the association between short (<3rd percentile) and tall (>3rd percentile) stature and risk of death, compared with less extreme heights. RESULTS: Over a median follow-up of 7.1 years, there were 1721 deaths. Risk of death was higher in children with short (hazard ratio, 1.49; 95% confidence interval, 1.33 to 1.66) and tall stature (hazard ratio, 1.32; 95% confidence interval, 1.03 to 1.69) in adjusted analysis. In secondary analyses, there was a statistically significant interaction between height and body mass index categories (P=0.04), such that the association of tall stature with higher mortality was limited to children with elevated body mass index (defined as ≥95th percentile for age and sex). Children with short stature had a higher risk of cardiac- and infection-related death, whereas children with tall stature had a higher risk of cancer-related death. CONCLUSIONS: Children with short and tall stature are at higher mortality risk, although this association was modified by body mass index at time of first RRT. Studies to further explore the reasons behind the higher risk of mortality in children with extremes of height at the time of first RRT are warranted.

Growth following solid organ transplantation in childhood.

One of the ultimate goals of successful solid organ transplantation in pediatric recipients is attaining an optimal final adult height. This manuscript will discuss growth following transplantation in pediatric recipients of kidney, liver, heart, lung or small bowel transplants. Remarkably similar factors impact growth in all of these recipients. Age is a primary factor, with younger recipients exhibiting the greatest immediate catch-up growth. Graft function is a significant contributing factor, with a reduced glomerular filtration rate correlating with poor growth in kidney recipients and the need for re-transplantation with impaired growth in liver recipients. The known adverse impact of steroids on growth has led to modification of the steroid dose and even steroid withdrawal and avoidance. In kidney and liver recipients, this strategy has been associated with the development of acute rejection. In infant heart transplantation, avoiding maintenance corticosteroid immunosuppression is associated with normal growth velocity in the majority of patients. With marked improvements in patient and graft survival rates in pediatric organ recipients, quality of life issues, such as normal adult height, should now receive paramount attention. In general, normal growth following solid organ transplantation should be an achievable goal that results in normal adult height.

Alemtuzumab with corticosteroid minimization for pediatric deceased donor renal transplantation: a seven-yr experience.

Alemtuzumab is a monoclonal antibody targeting CD52 receptors on B and T lymphocytes and is an effective induction agent in pediatric renal transplantation. We report a seven-yr experience using alemtuzumab induction and steroid-free protocol in the pediatric population as safe and effective. Twenty-one pediatric deceased donor renal transplants were performed at a single academic institution. All received induction with single-dose alemtuzumab and were maintained on a steroid-free protocol using TAC and MMF immunosuppression. There were 15 males and six females in the study whose ages ranged from one to 19 yr. The average follow-up was 32 months (range from 12 to 78.2 months and median 33.7 ± 23.7 months). All patients had immediate graft function. Graft survival was 95%, and patient survival was 100%. Mean 12 and 36 months eGFR were 63.33 ± 21.01 and 59.90 ± 15.27 mL/min/1.73m(2), respectively. Three patients developed acute T-cell-mediated rejection due to non-adherence while no recipients developed cytomegalovirus infection, PTLD, or polyoma BK viral nephropathy. Steroid avoidance with single-dose alemtuzumab induction provides adequate and safe immunosuppression in pediatric deceased donor renal transplant recipients receiving TAC and low-dose MMF maintenance therapy.

Growth following solid organ transplantation in childhood

One of the ultimate goals of successful solid organ transplantation in pediatric recipients is attaining an optimal final adult height. This manuscript will discuss growth following transplantation in pediatric recipients of kidney, liver, heart, lung or small bowel transplants. Remarkably similar factors impact growth in all of these recipients. Age is a primary factor, with younger recipients exhibiting the greatest immediate catch-up growth. Graft function is a significant contributing factor, with a reduced glomerular filtration rate correlating with poor growth in kidney recipients and the need for re-transplantation with impaired growth in liver recipients. The known adverse impact of steroids on growth has led to modification of the steroid dose and even steroid withdrawal and avoidance. In kidney and liver recipients, this strategy has been associated with the development of acute rejection. In infant heart transplantation, avoiding maintenance corticosteroid immunosuppression is associated with normal growth velocity in the majority of patients. With marked improvements in patient and graft survival rates in pediatric organ recipients, quality of life issues, such as normal adult height, should now receive paramount attention. In general, normal growth following solid organ transplantation should be an achievable goal that results in normal adult height.

Solid organ transplantation following end-organ failure in recipients of hematopoietic stem cell transplantation in children.

Hematopoietic stem cell transplantation (HSCT) is an accepted treatment modality for various malignant and non-malignant disorders of the lympho-hematopoietic system. Patient survival rate has increased significantly with the use of this procedure. However, with the increase in disease-free patient survival rates, complications including various organ toxicities are also common. Kidney, liver, lung, heart, and skin are among those solid organs that are commonly affected and frequently lead to organ dysfunction and eventually end-organ disease. Conservative measures may or may not be successful in managing the organ failure in these patients. Solid organ transplantation has been shown to be promising in those patients who fail conservative management. This review will summarize the causes of solid organ (kidney, liver, and lung) dysfunction and the available data on transplantation of these solid organs in post-HSCT recipients.

Growth hormone treatment after renal transplantation: a promising but underused chance to improve growth.

Growth retardation remains a clinical problem in children with chronic kidney disease (CKD) prior to and during end-stage renal disease. The growth of approximately 40 % of children on dialysis is stunted. Even so, growth hormone treatment (GH) is not used in the majority of small children prior to transplantation. Also, GH is effective in improving growth after transplantation, but again, it is only rarely used in this situation mainly for fear of triggering rejection episodes. In controlled studies, the number of patients who developed rejection episodes with GH was no greater than the number in untreated controls. However, patients with prior frequent rejection episodes developed further repeated subsequent rejection episodes. Many patients with repeated rejection episodes before GH treatment have reduced renal function and are expected to proceed to dialysis or retransplantation. We believe that in these patients, early individual decisions for or against GH treatment should be made as soon as other treatment strategies, such as steroid withdrawal, have failed or are not indicated. Decisions for GH treatment at a later pubertal age come too late for significant growth response and/or improvement of final height.

Clinical trial of focal segmental glomerulosclerosis in children and young adults.

This NIH-funded multicenter randomized study of focal segmental glomerulosclerosis (FSGS) treatment compared the efficacy of a 12-month course of cyclosporine to a combination of oral pulse dexamethasone and mycophenolate mofetil in children and adults with steroid-resistant primary FSGS. Of the 192 patients enrolled, 138 were randomized to cyclosporine (72) or to mycophenolate/dexamethasone (66). The primary analysis compared the levels of an ordinal variable measuring remission during the first year. The odds ratio (0.59) for achieving at least a partial remission with mycophenolate/dexamethasone compared to cyclosporine was not significant. Partial or complete remission was achieved in 22 mycophenolate/dexamethasone- and 33 cyclosporine-treated patients at 12 months. The main secondary outcome, preservation of remission for 26 weeks following cessation of treatment, was not significantly different between these two therapies. During the entire 78 weeks of study, 8 patients treated with cyclosporine and 7 with mycophenolate/dexamethasone died or developed kidney failure. Thus, our study did not find a difference in rates of proteinuria remission following 12 months of cyclosporine compared to mycophenolate/dexamethasone in patients with steroid-resistant FSGS. However, the small sample size might have prevented detection of a moderate treatment effect.

Clinical trials treating focal segmental glomerulosclerosis should measure patient quality of life.

Optimal therapy of patients with steroid-resistant primary focal segmental glomerulosclerosis (FSGS) remains controversial. This report describes the initial study design, baseline characteristics, and quality of life of patients enrolled in the FSGS Clinical Trial, a large multicenter randomized study of this glomerulopathy comparing a 12-month regimen of cyclosporine to the combination of mycophenolate mofetil and oral dexamethasone. Patients with age ranging 2-40 years, with an estimated glomerular filtration rate > 40 ml/min per 1.73 m², a first morning urine protein-to-creatinine ratio over one, and resistant to corticosteroids were eligible. The primary outcome was complete or partial remission of proteinuria over 52 weeks after randomization. In all, 192 patients were screened, of whom 138 were randomized for treatment. Ethnic distributions were 53 black, 78 white, and 7 other. By self- or parent-proxy reporting, 26 of the 138 patients were identified as Hispanic. The baseline glomerular filtration rate was 112.4 (76.5, 180.0) ml/min per 1.73 m², and urine protein was 4.0 (2.1, 5.3) g/g. Overall, the quality of life of the patients with FSGS was lower than healthy controls and similar to that of patients with end-stage renal disease. Thus, the impact of FSGS on quality of life is significant and this measurement should be included in all trials.

Etiology and treatment of growth retardation in children with chronic kidney disease and end-stage renal disease: a historical perspective.

Dramatic changes have occurred in our understanding of the etiology of the growth retardation associated with chronic kidney disease (CKD) and end-stage renal disease (ESRD) during the past 50 years. Significant interest has been focused on preventing and/or correcting the growth retardation because of the emergence of the dual therapeutic modalities of dialysis and renal transplantation to prolong the lives of infants, children, and adolescents afflicted with CKD and ESRD. These efforts have resulted in a significant improvement in the height Z-score over the past two decades of children with CKD and ESRD. This has had a salutary impact on the final adult height of such children which should hopefully lead to an enhanced quality of life in the future. This report addresses the progress that has been made in the management of growth retardation in the pediatric population with CKD and ESRD.

What have 20 years of data from the North American Pediatric Renal Transplant Cooperative Study taught us about growth following renal transplantation in infants, children, and adolescents with end-stage renal disease?

Growth following renal transplantation in infants, children, and adolescents was evaluated from 20 years of data reported to the registry of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS). The analysis of more than 10,000 recipients addressed the following questions: 1. What is the impact of age, pubertal growth, gender, transplant history, donor source and allograft function on growth after transplantation? 2. Has the height Z score at the time of transplantation changed during the past two decades and has this influenced final adult height? 3. To what extent has recombinant human growth hormone (rhGH) been utilized in growth retarded recipients after transplantation and has its use resulted in accelerated post-transplantation growth? 4. Has the use of steroids for maintenance immunosuppression changed over the past 20 years and how have the perturbations of steroid usage influenced post-transplantation growth? 5. Have changes in clinical care resulted in improved final adult height Z score during the past two decades? Only younger children (<6 years) had initial accelerated post-transplantation growth. The mean increment in height during puberty was 18.8 cm (21.7 cm in 4.7 years for boys and 14.3 cm in 4.5 years for girls). Gender, source of donor graft, or number of grafts did not influence growth. Height Z score at transplantation has improved over the past two decades, as has final adult height with each succeeding era. The use of rhGH after transplantation results in a delta Z score of +0.5 standard deviation (SD). Post-transplantation growth improves with steroid avoidance and changes in estimated glomerular filtration rate (eGFR) impact on growth.