Outcomes after renal transplantation for FSGS in children

Post-transplant glomerular diseases: update on pathophysiology, risk factors and management strategies

In recent years, advancements in immunosuppressive medications and post-transplant management have led to a significant decrease in acute rejection rates in renal allografts and consequent improvement in short-term graft survival. In contrast, recent data have shown an increased incidence of post-transplant glomerular diseases, which currently represent a leading cause of allograft loss. Although pathogenesis is not fully understood, growing evidence supports the role of inherited and immunological factors and has identified potential pre- and post-transplant predictors. In this review, we illustrate recent advancements in the pathogenesis of post-transplant glomerular disease and the role of risk factors and immunological triggers. In addition, we discuss potential prevention and management strategies.

Incidence, risk factors, and outcomes of recurrent focal segmental glomerulosclerosis in pediatric kidney transplant recipients: A systematic review and meta-analysis

BACKGROUND

Focal segmental glomerulosclerosis is the most prevalent acquired kidney disease leading to end-stage renal disease in children and has a propensity for recurring in the transplanted kidney. The recurrence of FSGS after kidney transplantation in children varies greatly. In addition, the risk factors and outcomes of recurrence of FSGS remain controversial. This study evaluated the recurrence rate, risk factors, and prognosis of FSGS after kidney transplantation in order to provide advice and assistance in clinical decision-making for pediatric kidney transplantation.

METHODS

PubMed, Embase, Web of Science, CNKI, and other databases were searched from the establishment of the repository to March 2022. We extracted data on incidence, risk factors, and outcomes.

RESULTS

The results showed that the recurrence rate of primary FSGS in children after renal transplantation was 48% (95% CI 36%-59%) and the recurrence rate of FSGS (all forms) was 35% (95% CI 17%-52%). The graft loss rate of primary FSGS in children after kidney transplantation was 29% (95% CI 17%-42%) and the graft loss rate of FSGS (all forms) was 29% (95% CI 4%-62%). 57% (95% CI 42%-73%) of pediatric patients with recurrent primary FSGS showed complete remission. Risk factor analyses showed that age of onset (SMD .69, 95% CI .20-1.19, p = .006) was related to the recurrence of primary FSGS, whereas the living related donor was not a risk factor for recurrent primary FSGS in pediatrics after kidney transplantation (OR 1.22, 95% CI .48-3.10, p = .674).

CONCLUSIONS

The recurrence rate and graft loss rate of FSGS in children after kidney transplantation were relatively high. Age at onset was associated with a risk for recurrent primary FSGS, whereas the living related donor was not a risk factor for recurrent FSGS in pediatric kidney recipients.

Primary Focal Segmental Glomerulosclerosis Recurrence After Pediatric Renal Transplantation

OBJECTIVES

Focal segmental glomerulosclerosis recurrence after renal transplant occurs frequently in pediatric patients and is associated with poor graft survival when patients reach adulthood. We investigated recurrence rates, recurrence risk factors, management strategies, and long-term graft function among pediatric renal transplant recipients with focal segmental glomerulosclerosis as primary disease.

MATERIALS AND METHODS

We retrospectively evaluated medical records of 34 pediatric patients with primary focal segmental glomerulosclerosis who had undergone renal transplant between 2004 and 2019 at our center. Focal segmental glomerulosclerosis recurrence was diagnosed by the presence of nephrotic range proteinuria after transplant and confirmed by graft biopsy. Preoperative prophylactic plasma exchange was administered to pediatric renal transplant recipients with primary focal segmental glomerulosclerosis. Plasma exchange was also used to treat focal segmental glomerulosclerosis recurrence, with rituximab added if the patient did not respond to plasma exchange.

RESULTS

All patients (male-to-female ratio of 19:15) in our group underwent renal transplant. Mean patient age at the time of transplant was 12.72 ± 5.46 years. Twenty-nine patients received living- related donor allografts (85.3%) and 5 received organs from deceased donors (14.7%). We identified focal segmental glomerulosclerosis recurrence in 5 recipients (14.7%). Time from focal segmental glomerulosclerosis diagnosis to end-stage renal disease and duration of dialysis were shorter in the recurrence group than in the nonrecurrence group (48.4 months [range, 2-90 mo] vs 65.1 months [range, 8-123 mo] and 1.41 ± 0.82 vs 3.18 ± 1.88 years, respectively; P < .05). Donor type and transplant age were similar in both groups. Of those with recurrence who had received plasma exchange and rituximab, 3 patients (75%) had complete remission and 1 patient (25%) had partial remission.

CONCLUSIONS

Prophylactic plasma exchange and the combined plasma exchange-rituximab regimen for treatment of focal segmental glomerulosclerosis recurrence resulted in low recurrence and good remission rates in our pediatric cohort.

Steroid avoidance/withdrawal and maintenance immunosuppression in pediatric kidney transplantation

BACKGROUND

Corticosteroids have been an integral part of maintenance immunosuppression for pediatric kidney transplantation. However, prolonged steroid therapy is associated with significant toxicities resulting in several SW/avoidance strategies in recent years.

METHOD/OBJECTIVE

This comprehensive review aims to discuss steroid-related toxicities and the safety, efficacy, and benefit of steroid avoidance/withdrawal immunosuppression in pediatric kidney transplant recipients.

RESULTS

Initial studies of SW/avoidance conducted in the setting of CSA and AZA showed an increased incidence of AR but no increase in graft loss or mortality with SW/avoidance maintenance immunosuppression. Studies performed under modern immunosuppression (induction therapy, Tac, and MMF) show no significant increase in AR or graft loss with SW/avoidance immunosuppression. Furthermore, SW/avoidance immunosuppression is associated with significant improvement in growth, BMI, BP control, and lipid profile in pediatric kidney transplant recipients. Despite these data, SW/avoidance remains controversial, and only 40% of pediatric kidney transplant recipients in the United States are currently on SW/avoidance maintenance immunosuppression.

CONCLUSION

SW/avoidance maintenance immunosuppression is safe and associated with fewer side effects compared with steroid-inclusive maintenance immunosuppression in pediatric kidney transplant recipients.

Pediatric focal segmental glomerulosclerosis: favorable transplantation outcome with plasma exchange

Background

Although kidney transplantation (KTX) is the treatment of choice for pediatric end stage kidney disease (ESKD); concerns for recurrence in cases of focal segmental glomerulosclerosis (FSGS) are still present. This study aimed to investigate the outcome of KTX in children with ESKD secondary to FSGS, with implementation of preemptive perioperative plasma exchange (PE) for non-genetically proven patients.

Methods

Forty FSGS pediatric kidney transplant recipients were studied. Of them: 12 patients (30%) had genetically proven NPHS2 mutations/familial and 28 (70%) were sporadic FSGS patients. All sporadic patients electively received 6 perioperative PE sessions. Patients with recurrence of proteinuria (n = 13; including 3 patients with genetic/familial and 10 patients with sporadic FSGS) were managed with PE and Rituximab (RTX). Kaplan-Meier curves were used to analyze graft and recurrence free survival data.

Results

The mean follow-up duration after KTX was 3.8 ± 2.86 years. Recurrence of proteinuria was encountered early postoperative in 11 patients (27.5%) and late (1.6 and 2.9 years after KTX) in 2 patients (5%). All patients with early recurrence achieved complete remission, while patients with late recurrence developed graft failure. Current serum creatinine and proteinuria levels were not different in patients received PE (n = 31) and patients did not PE (n = 9) (p = 0.308 and 0.287 respectively). Current serum creatinine and proteinuria levels in sporadic patients (n = 28) after prophylactic perioperative PE were not different from those of genetic/ familial patients (n = 12) (p = 0.303 and 0.144 respectively). Proteinuria was less in patients underwent native nephrectomy than others immediately postoperative and at assessment (p = 0.002 & 0.0031 respectively). One-year graft and patient survival was 93.8% with a mean 1-year serum creatinine of 0.67 ± 0.25 mg/dl. Three graft losses (7.5%) were due to chronic rejection 3.3, 3.75 and 4.17 years after KTX and 2 patients’ mortality (5%) occurred early postoperative (first 2 weeks).

Conclusion

FSGS transplanted children have favorable outcomes with perioperative PE for non-genetically proven cases. Early recurrence after KTX can be successfully managed with PE and RTX.

HLA Loci and Recurrence of Focal Segmental Glomerulosclerosis in Pediatric Kidney Transplantation

Recurrent focal segmental glomerulosclerosis (FSGS) after kidney transplantation accounts for the majority of allograft failures in children with primary FSGS. Although current research focuses on FSGS pathophysiology, a common etiology and mechanisms of disease recurrence remain elusive.

Podocyte Sphingolipid Signaling in Nephrotic Syndrome

Podocytes play a vital role in the pathogenesis of nephrotic syndrome (NS), which is clinically characterized by heavy proteinuria, hypoalbuminemia, hyperlipidemia, and peripheral edema. The pathogenesis of NS has evolved through several hypotheses ranging from immune dysregulation theory and increased glomerular permeability theory to the current concept of podocytopathy. Podocytopathy is characterized by dysfunction or depletion of podocytes, which may be caused by unknown permeability factor, genetic disorders, drugs, infections, systemic disorders, and hyperfiltration. Over the last two decades, numerous studies have been done to explore the molecular mechanisms of podocyte injuries or NS and to develop the novel therapeutic strategies targeting podocytopathy for treatment of NS. Recent studies have shown that normal sphingolipid metabolism is essential for structural and functional integrity of podocytes. As a basic component of the plasma membrane, sphingolipids not only support the assembly of signaling molecules and interaction of receptors and effectors, but also mediate various cellular activities, such as apoptosis, proliferation, stress responses, necrosis, inflammation, autophagy, senescence, and differentiation. This review briefly summarizes current evidence demonstrating the regulation of sphingolipid metabolism in podocytes and the canonical or noncanonical roles of podocyte sphingolipid signaling in the pathogenesis of NS and associated therapeutic strategies.

Clinical practice recommendations for recurrence of focal and segmental glomerulosclerosis/steroid-resistant nephrotic syndrome

Recurrence of primary disease is one of the major risks for allograft loss after pediatric RTx. The risk of recurrence of FSGS/SRNS after pediatric RTx in particular can be up to 86% in idiopathic cases. There is a need for consensus recommendations on its prevention and treatment. The CERTAIN study group has therefore performed a thorough literature search based on the PICO model of clinical questions to formulate educated statements to guide the clinician in the process of decision-making. A set of educated statements on prevention and treatment of FSGS/SRNS after pediatric RTx has been generated after careful evaluation of available evidence and thorough panel discussion. We do not recommend routine nephrectomy prior to transplantation; neither do we recommend abstaining from living donation. Special attendance needs to be given to those patients who had already experienced graft loss due to FSGS/SRNS recurrence. Early PE or IA with or without high-dose CsA and/or rituximab seems to be most promising to induce remission. The educated statements presented here acknowledge that FSGS/SRNS recurrence after pediatric RTx remains a major concern and is associated with shorter graft survival or even graft loss. The value of any recommendation needs to take into account that evidence is based on cohorts that differ in ethnicity, pre-transplant history, immunosuppressive regimen, definition of recurrence (eg, clinical and/or histological diagnosis) and treatment modalities of recurrence.

Therapeutic Options for Recurrence of Primary Focal Segmental Glomerulonephritis (FSGS) in the Renal Allograft: Single-Center Experience

Focal Segmental Glomerulosclerosis (FSGS) recurrence after kidney transplantation (KTx) is relatively frequent and is associated with poor graft survival. The aim of this study was to investigate which management strategies were associated with better outcomes in our cohort of KTx recipients with primary FSGS. We retrospectively collected data on patients with primary FSGS who received a KTx between 1993 and 2019. A history of biopsy proven FSGS in native kidneys and new onset of significant proteinuria early post-KTx led to the diagnosis of recurrence, which was confirmed by graft biopsy. From 1993 to 2019 we performed 46 KTxs in patients with primary FSGS. We identified 26 episodes of recurrence in 25 patients, 67% of them occurring in males. They were younger at the time of KTx (33.8 vs. 41.1 years old, p = 0.067) and had progressed to end stage renal disease (ESRD) faster after FSGS diagnosis (61.4 vs. 111.2 months, p = 0.038), while they were less likely to have received prophylactic plasmapheresis (61.5% vs. 90%, p = 0.029). 76.7% of recurrences were found early, after a median of 0.5 months (IQR 0.1-1) with a median proteinuria was 8.5 (IQR 4.9-11.9) g/day. All patients with recurrence were treated with plasmapheresis, while 8 (30.7%) additionally received rituximab, 1 (3.8%) abatacept, and 4 (15.4%) ACTH. 7 (27%) patients experienced complete and 11 (42.3%) partial remission after a mean time of 3 (±1.79) and 4.4 (±2.25) months, respectively. Prognosis was worse for patients who experienced a recurrence. Eleven (42.3%) patients lost their graft from FSGS in a median time of 33 (IQR 17.5-43.3) months. In this series of patients, primary FSGS recurred frequently after KTx. Prophylacic plasmapheresis was shown efficacious in avoiding FSGS recurrence, while timely diagnosis and plasmapheresis-based regimens induced remission in more than half of the patients.

Factors Influencing Disease Recurrence and Graft Survival in Patients who Developed End-Stage Renal Disease Due to Focal Segmental Glomerulosclerosis and Underwent Renal Transplantation

Aim

The aim of our study was to determine the factors effecting disease recurrence and graft survival in patients who developed end-stage renal disease (ESRD) due to focal segmental glomerulosclerosis (FSGS) and underwent renal transplantation (Rtx).

Methods

A total of 37 patients with FSGS (female/male: 10/27) who underwent Rtx in our transplant center between 2001 and 2014 were included in the study. The patients were diagnosed with FSGS by biopsy. Comparative analyses were performed in order to determine the factors effecting disease recurrence and graft survival. Plasmapheresis was performed with 40 mL/kg plasma. The diagnosis of the recurrence of FSGS and the acute rejections were also confirmed by biopsy.

Results

Statistical analyses revealed that, recurrence rates were higher in Rtx recipients from deceased donor [deceased donor versus living donor, 2 (50.0%) versus 3 (9.1%), P = 0.024]. However, no correlation was found between recurrence and renal replacement treatment (RRT) methods, duration of RRT, preoperative or postoperative prophylactic plasmapheresis, the presence of preoperative nephrotic proteinuria, donor's or recipient's age or gender, kinship with donor, time interval between development of FSGS and ESRD, or performing native nephrectomy. Graft survival rates were higher in Rtx patients that were transplanted from living donor, first-degree relatives, and in patients without recurrence.

Conclusion

In countries where organ donation is insufficient, living donors can be used with a low risk of recurrence for Rtx candidates with FSGS. Also, grafts from living donors, particularly from first-degree relatives, have higher survival rates.

Recurrent Glomerulonephritis after Renal Transplantation: The Clinical Problem

Glomerulonephritis (GN) continues to be one of the main causes of end-stage kidney disease (ESKD) with an incidence rating from 10.5% to 38.2%. Therefore, recurrent GN, previously considered to be a minor contributor to graft loss, is the third most common cause of graft failure 10 years after renal transplantation. However, the incidence, pathogenesis, and natural course of recurrences are still not completely understood. This review focuses on the most frequent diseases that recur after renal transplantation, analyzing rate of recurrence, epidemiology and risk factors, pathogenesis and bimolecular mechanisms, clinical presentation, diagnosis, and therapy, taking into consideration the limited data available in the literature. First of all, the risk for recurrence depends on the type of glomerulonephritis. For example, recipient patients with anti-glomerular basement membrane (GBM) disease present recurrence rarely, but often exhibit rapid graft loss. On the other hand, recipient patients with C3 glomerulonephritis present recurrence in more than 50% of cases, although the disease is generally slowly progressive. It should not be forgotten that every condition that can lead to chronic graft dysfunction should be considered in the differential diagnosis of recurrence. Therefore, a complete workup of renal biopsy, including light, immunofluorescence and electron microscopy study, is essential to provide the diagnosis, excluding alternative diagnosis that may require different treatment. We will examine in detail the biomolecular mechanisms of both native and transplanted kidney diseases, monitoring the risk of recurrence and optimizing the available treatment options.

Effect of Glomerulopathy Recurrence in the Outcome and Graft Survival of Kidney Transplanted Patients

BACKGROUND

Recurrent glomerulopathy (GP) after kidney transplantation is a complication of kidney transplantation that could negatively affect kidney function and graft survival. This study aimed to evaluate the outcome, graft survival, and GP recurrence and its predictive factors in kidney-transplanted patients.

METHODS

Patients were divided into 2 groups: G1 (with GP; n = 95) and G2 (with other causes of end-stage renal disease; n = 373). Graft survival analyses were performed using the Kaplan-Meier for living donor (LD) and deceased donor (DD). Cox proportional hazards regression were used to investigate the predictors for graft loss and for GP recurrence.

RESULTS

Disease recurrence was observed in 9 patients who received a kidney from an LD, of which 4 lost their grafts. In patients who received a kidney from a DD, recurrence was also observed in 9 patients, of which 3 lost their grafts. No statistically significant differences in graft survival between G1 and G2 in relation to LD and DD were noted (P = .299 and .434, respectively). However, differences in graft survival were found when GP subtypes and GP recurrence were analyzed. The predictors of graft loss were delayed graft function (hazard ratio [HR] = 2.226, P = .002), rejection episodes (HR = 1.904, P = .017), and recurrence or transplant GP (HR = 3.243, P = .006). The predictors of disease recurrence or transplant GP were age (HR = 0.945, P = .028) and cold ischemia time (HR = 1.117, P = .003).

CONCLUSION

Kidney transplantation could be a reasonable treatment for GP with end-stage renal disease. Despite the disease recurrence, which is a significant cause of graft loss in transplant recipients, graft survival remains satisfactory.

Risk factors associated with allograft failure in pediatric kidney transplant recipients with focal segmental glomerulosclerosis

BACKGROUND

With improved outcomes for children transplanted with FSGS since previous NAPRTCS registry reports, this study re-evaluates the association of living donation, immunosuppression, and DGF on graft survival.

SETTING

Patients transplanted between 2002 and 2016, comparing FSGS diagnosis vs other glomerular diseases.

METHODS

Primary outcomes were allograft survival and FSGS recurrent-free graft survival. Potential risk factors were obtained at the time of transplant and up to 30 days post-transplantation. Analysis considered a priori that DGF may be a proxy for severe FSGS recurrence. Multivariable survival models for outcome were tested for sensitivity without/with DGF to determine features independent of recurrence.

RESULTS

From the larger cohort of 3010 patients, 5-year graft survival in children with FSGS (n = 455) was worse (74.3%) compared with other glomerular diseases (87.1%, n = 690) (HR 1.45, P = 0.033). Modeling all glomerular diseases, survival risk was associated with deceased donor (HR 1.83, P = 0.002), re-transplantation (HR 1.58, P = 0.013), and recipient age (HR 1.06/y, P = 0.002). The living donor advantage was not confirmed in a FSGS model (HR 1.51 for deceased, P = 0.12). DGF was highly associated with graft failure (HR 4.39, P < 0.001) and independent of re-transplant history but not FSGS diagnosis. Induction agents or primary immunosuppression choices were not associated with survival.

CONCLUSION

Graft survival rates have improved since the previous report. Living donor did not predict graft failure, but there remains no survival advantage. DGF was the primary independent predictor for graft loss secondary to FSGS recurrence, consistent with DGF being a proxy for severe recurrent disease.

European Society of Pediatric Nephrology survey on current practice regarding recurrent focal segmental glomerulosclerosis after pediatric kidney transplantation

INTRODUCTION

Primary FSGS is an important cause of ESRD in children. FSGS recurrence after kidney transplantation is associated with early graft loss. No guidelines for treatment of FSGS recurrence exist. We conducted a survey to gain insight into variation of treatment between centers.

METHODS

A survey was sent to all members of the ESPN on behalf of the "Renal Transplantation" and "Idiopathic Nephrotic Syndrome" working groups.

RESULTS

Fifty-nine nephrologists from 31 countries responded, reporting 807 FSGS patients, with 241 (30%) FSGS recurrences after transplantation. Recurrence varied from 0% to 100% between respondents. Native nephrectomy before or during transplantation was performed, respectively, always (37%), never (39%), or on clinical indication (17%). Half of the respondents started preventive treatment before transplantation, using PF (n = 10); R (n = 4); PF or IA, plus R (n = 9); cyclosporine (n = 2); or unknown (n = 4). Immunosuppressive therapy for patients without known mutations consisted of a combination of steroids, tacrolimus/cyclosporine, and MMF, with or without IL-2R-blockade in, respectively, 61% and 86% of the respondents. Sixty-three percent applied a similar regimen to patients with known mutations. FSGS recurrence was treated with PF or IA, plus R by 66% of respondents; 54% observed no response. Complete remission in >50% of patients was reported by 41% of the respondents.

DISCUSSION

FSGS recurrence after transplantation is common, but varies greatly between centers. We found great variability in preventive and therapeutic treatment regimens. Future research should focus on predisposing factors, including biopsy findings and genetic mutations, and standardized treatment.

Successful Treatment of Recurrent Focal Segmental Glomerulosclerosis After Transplantation in Children: A Single-Center Experience

OBJECTIVE

We aim to report our experience managing cases of recurrent focal segmental glomerulosclerosis (FSGS) in a group of pediatric renal transplant recipients.

METHODS

This study was a retrospective chart review of pediatric patients who had their first kidney transplant at King Faisal Specialist Hospital & Research Center between 2014 and 2016.

RESULTS

We reviewed the files of 6 patients, 3 of whom were male. The median age of the children was 2.75 years (range, 2-4 years) at disease onset, with an average time of progression to end-stage renal disease of 19 months (range, 8-30 months). Five of the patients received a living related donor transplant, and 1 received a living nonrelated donor transplant. Patients had FSGS recurrence at varying intervals (1 to 3 days) post transplant. All cases had plasmapheresis prior to receiving abatacept or rituximab. The therapeutic strategy in 4 patients involved switching tacrolimus to cyclosporine. A complete response was observed in 5 of the 6 patients (83.3%), and treatment was well tolerated in 5 patients. Patient 1 had severe oliguria and required intermittent hemodialysis during the first 3 weeks post transplant. He showed minimal response to the therapeutic plasma exchange and rituximab and was subsequently treated with abatacept. However, he died 8 months post transplant of pneumonia and sepsis.

CONCLUSION

Rituximab and switching tacrolimus to cyclosporine, in conjunction with plasmapheresis, appeared to be effective and safe in children with recurrent FSGS. Conversely, abatacept did not appear to provide clinical benefit.

Translational Aspects of Sphingolipid Metabolism in Renal Disorders

Sphingolipids, long thought to be passive components of biological membranes with merely a structural role, have proved throughout the past decade to be major players in the pathogenesis of many human diseases. The study and characterization of several genetic disorders like Fabry's and Tay Sachs, where sphingolipid metabolism is disrupted, leading to a systemic array of clinical symptoms, have indeed helped elucidate and appreciate the importance of sphingolipids and their metabolites as active signaling molecules. In addition to being involved in dynamic cellular processes like apoptosis, senescence and differentiation, sphingolipids are implicated in critical physiological functions such as immune responses and pathophysiological conditions like inflammation and insulin resistance. Interestingly, the kidneys are among the most sensitive organ systems to sphingolipid alterations, rendering these molecules and the enzymes involved in their metabolism, promising therapeutic targets for numerous nephropathic complications that stand behind podocyte injury and renal failure.

Increased glomerulonephritis recurrence after living related donation

Background

Kidney transplantation confers superior outcomes for patients with end stage kidney disease, and live donor kidneys associate with superior outcomes compared to deceased donor kidneys. Modern immunosuppression has improved rejection rates and transplant survival and, as a result, recurrence of glomerulonephritis has emerged as a major cause of allograft loss. However, many glomerulonephritides have significant genetic risk which may manifest through kidney intrinsic or systemic mechanisms. We hypothesise that heritable kidney intrinsic predisposition to glomerulonephritis will result in increased risk of glomerulonephritis recurrence in kidneys transplanted from genetically related donors.

Methods

We investigated the effect of living related donation on rates of recurrence and subsequent graft outcomes in 7236 patient from 28 years of ANZDATA transplant registry data. Data were analysed in R, using Kaplan Meier Survival analysis and adjusted analyses performed using Cox Proportional Hazards methods. A competing risk model was also analysed.

Results

Glomerulonephritis recurrence rates were significantly higher in living related donor grafts compared to either living unrelated or deceased donor grafts (p < 0 · 001). In IgA nephropathy, transplantation from living related donor kidneys demonstrated a 10 year recurrence rate of 16 · 7% compared to 7 · 1% in living unrelated donors and 9 · 2% in deceased donors (HR:1 · 7, 95% CI:1 · 26–2 · 26, p = 0 · 0005 for living related vs deceased donors). In focal segmental glomerulosclerosis, risk of recurrence at 10 years was 14 · 6% in living related donors compared to 10 · 8% in living unrelated donors and 6 · 6% in deceased donors (HR:2 · 2, 95% CI 1 · 34–3 · 64, p = 0 · 002) for living related vs deceased donors. Primary glomerulonephritis death censored graft survival was superior for living donor grafts, related or unrelated, compared to deceased donor grafts.

Conclusions

We identified a significant increase in the risk of glomerulonephritis recurrence in IgA Nephropathy and Focal Segmental Glomerulosclerosis in living related donors compared to a deceased donors.

Role of race in kidney transplant outcomes in children with focal segmental glomerulosclerosis

It is well established that racial differences exist in kidney transplant outcomes; however, there are no studies which focus on the role of race in transplant outcomes specifically in children diagnosed with FSGS. Associations between race and transplant outcomes in FSGS children were evaluated using the Organ Procurement and Transplantation Network database from 2000 to 2012. Recipients aged 2-21 years who received a kidney-only transplant were included. Multivariate regression models were used to evaluate transplant outcomes by race. Five hundred and thirty-six recipients (59.7% male, 15.6±3.9 years) were black and 1134 (55.7% male, 14.3±5.0 years) were non-black. Graft survival was significantly shorter in the black group (4.2±3.1 vs 4.6±3.3 years, P=.005). Black race was associated with significantly higher risk of graft failure (HR 1.34, 95% CI=1.21-1.49, P<.0001), acute rejection (OR 1.66 95% CI=1.39-1.97, P<.0001), and delayed graft function (OR 1.51, 95% CI=1.33-1.72, P<.001) compared to non-black race. There were no significant differences in mortality, prolonged hospitalization, or FSGS recurrence between groups. Race is a significant predictor for worse transplant outcomes in children with FSGS.

The role of plasma exchange in treating post-transplant focal segmental glomerulosclerosis: A systematic review and meta-analysis of 77 case-reports and case-series

Background

Evidence on the role of plasma exchange for treating recurrent post-transplant focal segmental glomerulosclerosis (FSGS) comes largely from individual cases and uncontrolled series. We conducted a systematic review and meta-analysis to estimate the remission rate after treatment with plasma exchange, and to determine if remission varied with patient or treatment characteristics.

Methods

We searched MEDLINE, EMBASE, Science Citation Index Expanded, and the Conference Proceedings Citation Index (Science and BIOSIS) for studies of patients with post-transplant recurrent FSGS who were treated with plasma exchange after recurrence (1950–2012). Of 678 studies screened, 77 met our inclusion criteria: 34 case reports (45 patients) and 43 case series (378 patients). We extracted patient-level data from each study and used random-effects models to calculate remission, defined as proteinuria <3.5 g/day (partial) or <0.5 g/day (complete).

Results

The overall remission rate in 423 patients with outcome data was 71 % (95 % CI: 66 % to 75 %). In 235 patients with data on age, remission was similar for adults and children: 69.1 % (95 % CI: 59.6 % to 77.2 %) and 70.2 % (95 % CI: 61.1 % to 77.9 %). Males were more likely to achieve remission (OR = 2.85; 95 % CI: 1.44 to 5.62) and patients treated within 2 weeks of recurrence showed a trend towards higher likelihood of remission (OR = 2.16; 95 % CI: 0.93 to 5.01). Proteinuria >7 g/day at recurrence was inversely associated with remission (OR = 0.43; 95 % CI: 0.19 to 0.97). Age and type of kidney transplant (living vs. deceased) did not associate with remission.

Conclusion

In this systematic review of patients with recurrent post-transplant FSGS, 71 % of patients achieved full or partial remission after treatment with plasma exchange; however, extensive missing data and lack of a control group limit any conclusions on causality.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-016-0322-7) contains supplementary material, which is available to authorized users.

Recurrence and Treatment after Renal Transplantation in Children with FSGS

Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage renal disease and a common pathologic diagnosis of idiopathic nephrotic syndrome (NS), especially in steroid-resistant cases. FSGS is known to recur after kidney transplantation, frequently followed by graft loss. However, not all patients with FSGS suffer from recurrence after kidney transplantation, and genetic and secondary FSGS have a negligible risk of recurrence. Furthermore, many cases of recurrence achieve remission with the current management of recurrence (intensive plasmapheresis/immunosuppression, including rituximab), and other promising agents are being evaluated. Therefore, a pathologic diagnosis of FSGS itself should not cause postponement of allograft kidney transplantation. For patients with a high risk of recurrence who presented with classical symptoms of NS, that is, severe edema, proteinuria, and hypoalbuminemia, close monitoring of proteinuria is necessary, followed by immediate, intensive treatment for recurrence.

Primary and Recurrent Focal Segmental Glomerulosclerosis Closely Link to Serum Soluble Urokinase-type Plasminogen Activator Receptor Levels

BACKGROUND

Serum soluble urokinase-type plasminogen activator receptor (suPAR) is implicated in the pathogenesis of native and recurrent focal segmental glomerulosclerosis (FSGS). It is elevated in two-thirds of subjects with primary FSGS, but not in people with other glomerular diseases that can differentiate FSGS and other glomerular diseases.

METHODS

We measured the serum soluble urokinase receptor levels and determined their association with clinical and pathologic data in 86 patients with primary FSGS, 5 repeat renal biopsy FSGS, and 6 recurrent FSGS post-transplantation. Healthy controls and patients with minimal change disease and membranous nephropathy were used as controls. The suPAR levels were measured by commercial enzyme-linked immunosorbent assay kits.

RESULTS

Patients with primary FSGS (median: 4232, interquartile range 1299-9714 pg/mL) had significantly higher levels of suPAR than those of patients with minimal change disease (median: 2784 pg/mL), membranous nephropathy (median: 3478 pg/mL), and healthy individuals (median: 1994 pg/mL). There was no significant difference in suPAR levels between the 65 patients with minimal change disease and 85 patients with membranous nephropathy. The suPAR levels increased in the 5 repeated renal biopsy FSGS and 6 recurrent FSGS post-transplantation.

CONCLUSIONS

The suPAR levels were significantly but positively correlated with FSGS, not only primary FSGS but also recurrent FSGS post-transplantation, but negatively correlated with other glomerular diseases. Thus, suPAR levels can differentiate primary FSGS and other glomerular diseases.

Focal segmental glomerulosclerosis recurrence in the renal allograft

Focal segmental glomerulosclerosis (FSGS) represents a common histologic pattern of glomerular injury associated with a multitude of disease mechanisms. The etiology of FSGS is often classified into primary (idiopathic) and secondary forms in response to genetic abnormalities, infections, toxins, and systemic disorders that lead to adaptive changes, glomerular hyperfiltration, and proteinuria. Our understanding of the pathogenic mechanisms responsible for FSGS was substantially enhanced in recent years because of major advances in the cell biology of the podocyte and parietal epithelial cell. Recurrence of FSGS occurs mainly in its primary form and is only rarely described in secondary forms. The re-enactment of pathologic mechanisms of FSGS as recurrent disease after kidney transplantation represents a biologic experiment that can provide unique insight. Nonetheless, recurrent FSGS remains a notable clinical problem that correlates with poorer renal allograft outcomes. This is the focus of this particular review, concentrating on the most recent developments.

Recurrence of idiopathic focal segmental glomerulosclerosis after kidney transplantation: experience of a Korean tertiary center

FSGS is the second most common cause of idiopathic NS in children. It often progresses to ESRD and commonly recurs after KT. To investigate the risk factors and the prognosis of recurrence in pediatric idiopathic FSGS in Korea, retrospective review of 43 KT in 38 children with idiopathic FSGS of last two decades was conducted. The patients presented at the median age of 5.1 yr (range 1.1-13.8 yr) and received KT 5.7 yr later (range 1.3-17.6 yr). FSGS recurred in 20 allografts immediately after transplantation, only in those who presented with NS but not in those who presented with AUA. The risk factors for recurrence were age of onset >5 yr and progression to ESRD within six yr but not sooner than 18 months. CR was achieved in 13 patients with FSGS recurrence and sustained in nine without subsequent relapse over a median of six and a half yr (0.6-20.7 yr). Pediatric idiopathic FSGS presenting with NS recurred in more than half of patients after transplantation. Interestingly, more rapid progression within less than 18 months did not predict recurrence. To identify high-risk patients of recurrence, an international cooperative study would be necessary.

Allogenic Aortic Graft as a Surgical Treatment of Aspergillus Aneurysm: A Case Report in a Kidney Transplant Recipient

Diagnosis and treatment of mycotic aneurysms in renal transplant recipients are extremely challenging. Choice of vascular prostheses, surgical techniques, diagnostic procedures, and medical treatment are still disputable. In this case report we present a recipient who developed an abdominal aortic aneurysm, infected with Aspergillus fumigatus, involving the major visceral arteries. In order to replace the aneurysmatic aorta and reconstruct the visceral arteries, the aneurysm was replaced surgically with a fresh AB0 compatible donor aortic graft together with donor iliac arteries. In addition to surgical treatment, this case highlights the diagnostic difficulties, modern anti-mycotic treatment, and underlying causes of this condition.

Success with plasmapheresis treatment for recurrent focal segmental glomerulosclerosis in pediatric renal transplant recipients

FSGS recurs in approximately 30% of transplanted kidneys and may lead to graft loss. We retrospectively examined the efficacy of early and intensive PP without additional IS in pediatric kidney transplant patients with recurrent FSGS at our center. Seven of 24 patients (29%) had nephrotic proteinuria and histologic evidence of FSGS recurrence within 1-5 days post-transplantation. PP was initiated early after transplantation and initially performed daily until sustained decline in proteinuria. PP frequency was then individually tapered according to proteinuria. Recurrent FSGS in all seven patients responded to a four- to 32-wk course of PP. Two of seven patients had a second recurrence of FSGS, and both recurrences remitted after an additional 3-6 wk of PP. Median observation period was 4.5 yr (0.8-16.3 yr). Complete remission of recurrent FSGS has been sustained in all seven patients, and all patients have stable graft function with recent plasma creatinine <1.5 mg/dL in six of seven patients. Most recent urine protein/creatinine is 0.13-0.61 mg/mg in six of seven patients. One patient has heavy proteinuria secondary to chronic allograft nephropathy 16 yr post-transplant. Intensive and prolonged PP, when initiated early in the post-operative period, is effective in treating recurrent FSGS and preventing graft loss without the use of additional immunosuppressants.

Podocyte pathology and nephropathy - sphingolipids in glomerular diseases

Sphingolipids are components of the lipid rafts in plasma membranes, which are important for proper function of podocytes, a key element of the glomerular filtration barrier. Research revealed an essential role of sphingolipids and sphingolipid metabolites in glomerular disorders of genetic and non-genetic origin. The discovery that glucocerebrosides accumulate in Gaucher disease in glomerular cells and are associated with clinical proteinuria initiated intensive research into the function of other sphingolipids in glomerular disorders. The accumulation of sphingolipids in other genetic diseases including Tay-Sachs, Sandhoff, Fabry, hereditary inclusion body myopathy 2, Niemann-Pick, and nephrotic syndrome of the Finnish type and its implications with respect to glomerular pathology will be discussed. Similarly, sphingolipid accumulation occurs in glomerular diseases of non-genetic origin including diabetic kidney disease (DKD), HIV-associated nephropathy, focal segmental glomerulosclerosis (FSGS), and lupus nephritis. Sphingomyelin metabolites, such as ceramide, sphingosine, and sphingosine-1-phosphate have also gained tremendous interest. We recently described that sphingomyelin phosphodiesterase acid-like 3b (SMPDL3b) is expressed in podocytes where it modulates acid sphingomyelinase activity and acts as a master modulator of danger signaling. Decreased SMPDL3b expression in post-reperfusion kidney biopsies from transplant recipients with idiopathic FSGS correlates with the recurrence of proteinuria in patients and in experimental models of xenotransplantation. Increased SMPDL3b expression is associated with DKD. The consequences of differential SMPDL3b expression in podocytes in these diseases with respect to their pathogenesis will be discussed. Finally, the role of sphingolipids in the formation of lipid rafts in podocytes and their contribution to the maintenance of a functional slit diaphragm in the glomerulus will be discussed.

Therapeutic plasma exchange for the treatment of pediatric renal diseases in 2013

Therapeutic plasma exchange is an extracorporeal treatment modality that removes systemic circulating pathologic factors or replaces absent plasma components and plays a role in many nephrologic conditions. It presents a number of technical challenges in the pediatric population but has become an increasingly common practice in pediatric nephrology over the past several decades. While prospective evidence is often lacking, our increased understanding of the molecular pathogenesis underlying many pediatric renal diseases provides sound reasoning for the use of plasma exchange in treating these conditions. This review will present the currently accepted indications for plasma exchange in children, the technical aspects of the procedure and its potential complications.

Focal segmental glomerulosclerosis in children: multivariate analysis indicates that donor type does not alter recurrence risk

BACKGROUND

Focal segmental glomerulosclerosis (FSGS), the second leading cause of end stage renal disease in children, appears to be increasing. Moreover, posttransplantation FSGS recurrence is a major problem, and there is concern that children receiving kidneys from living donors (LD) have increased recurrence risk.

METHODS

Data from the United Network for Organ Sharing from 1988 to 2008 were analyzed for number of de novo transplant recipients with a primary diagnosis of FSGS in children 1 to 20 years of age. Poisson regression was used for trend analysis. Univariate and multivariable logistic regression analyses were performed to examine the association of gender, race, human leukocyte antigen matching, age, and donor type with recurrence.

RESULTS

Trend analysis of kidney transplantations for FSGS in children (n=2157) showed an increase in cases of 5.8% per year or 209% over 20 years (P<0.0001). Recurrence was reported in 327 (15%) cases overall, with a preponderance for white recipients (P<0.001) in younger age subgroups (P<0.01). Donor type was significant (P=0.02), with recurrence reported in 17% versus 14% of recipients of kidneys from LDs versus deceased donors. Using multivariate analysis, recipients' young age (P=0.02) and white race (P<0.001) were identified as significant risk factors for recurrence, whereas receiving a LD kidney became insignificant.

CONCLUSIONS

FSGS as a cause of pediatric end-stage renal disease leading to transplantation is on the rise. FSGS recurrence is highest in young, white children, whereas receiving a LD kidney is not independently associated with increased risk of recurrence.

Allogeneic mesenchymal stem cell infusion for the stabilization of focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is the most frequent acquired renal condition resulting in end stage kidney disease in children. We describe a cell therapy treatment with human allogeneic bone marrow mesenchymal stem cells (MSC) in a 13-year-old patient developing recurrent FSGS after renal transplantation, which was not responding to conventional therapy. This treatment relied on the following measurements:clinical and laboratory evaluation of renal function, proteome array, biopsy, short tandem repeat assay. Before MSC treatment, the patient needed weekly plasmapheresis to achieve proteinuria-to-creatininuria ratio below 5. After three MSC infusions without adverse events, the patient has a stable renal function and the proteinuria target was reached without plasmapheresis. In addition, some circulating inflammatory factors decreased and their levels were still low after one year. This is the first report of an MSC treatment in an FSGS patient. Even though different factors may have contributed to the clinical results, after MSC infusion a stable reduction in the serum level of several inflammatory factors has been registered and the patient does not need anymore plasmapheresis to keep proteinuria under control. In addition, this encouraging single case let us identify some putative efficacy biomarkers that could be of clinical interest in chronic kidney diseases.

Recurrence of glomerulonephritis after renal transplantation

Recurrence of glomerulonephritis following renal transplantation is considered an important cause of allograft failure. The incidence of recurrence of glomerulonephritis varies widely depending on the definition of recurrence (pathologic recurrence or clinicopathologic recurrence) and the original glomerular disease. Moreover the impact of recurrence of glomerular disease on allograft outcome varies widely between different forms of glomerulonephritis. Whereas IgA nephritis recurs in up to one third of transplanted patients, this is not associated with adverse effects on graft survival. In contrast, recurrent focal segmental glomerulosclerosis and membranoproliferative glomerulopathy have an unfavorable prognosis. Overall, long-term graft survival in patients transplanted for glomerulonephritis is comparable to survival in patients with other causes of ESRD. In recent years, several mechanisms for recurrent disease after transplantation (e.g. PLA2R antibodies in membranous nephropathy and suPAR in FSGS) have been identified, and these findings have helped to elucidate the pathogenesis of glomerular diseases. Although renal transplantation is the treatment of choice for end-stage renal disease as a consequence of glomerulonephritis, further studies are required to develop optimal strategies to prevent, diagnose and treat recurrent glomerular diseases.

Combination of pulse methylprednisolone infusions with cyclosporine-based immunosuppression is safe and effective to treat recurrent focal segmental glomerulosclerosis after pediatric kidney transplantation

BACKGROUND

Recurrence of focal segmental glomerulosclerosis (FSGS) in pediatric kidney allografts is associated with poor graft survival. Several therapeutic regimens have been proposed, with conflicting results.

METHODS

Ten pediatric patients with recurrent FSGS after kidney transplantation were treated with a protocol of methylprednisolone (MP) infusions in combination with cyclosporine (CsA)-based immunosuppression. The patients received a drug regimen with infusions of 20 mg/kg MP on three consecutive days at week 1, week 3, and week 5, and then monthly until six months after transplantation. If a complete or partial remission (PR) was obtained, MP pulse continued every three months until 24 months after transplantation. The CsA dose was adjusted according to AUC0-4.

RESULTS

Seven of 10 patients (70%) achieved complete remission (CR) with stable renal function within 18 months of beginning of treatment. One of two patients with PR entered CR 3.5 yr after transplantation. One patient lost her graft due to recurrence four months after transplantation. After observation for 26-119 months, seven patients maintained remission with normal glomerular filtration rate. Few major side effects were observed in association with the high-dose MP infusion therapy.

CONCLUSIONS

MP infusion therapy in combination with CsA-based immunosuppression could be safe and effective in treating recurrent FSGS after kidney transplantation.

Rituximab in post-transplant pediatric recurrent focal segmental glomerulosclerosis

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) recurs in 20-40 % of allografts. Plasmapheresis (TPE) has been one of the mainstays of treatment with variable results. Rituximab (RTX), a monoclonal antibody to the protein CD20, is being used for treatment of recurrent FSGS (recFSGS) but pediatric experience is limited.

METHODS

We conducted a retrospective review of eight patients with recFSGS, treated with RTX (1-4 doses) after having minimal response to TPE. Complete response was defined as a decrease in urine protein creatinine ratio (Up/c) to less than 0.2 and partial response was a decrease in Up/c ratio by 50 % of baseline and in the sub-nephrotic range (U p/c <2).

RESULTS

Complete response was seen in two of eight patients, and partial response was seen in four of eight patients. Two patients had no response. At last follow-up, all the partial responders had sub-nephrotic range proteinuria (Up/c ratios ranging from 0.29 to 1.6). Delayed response, up to 9 months post-RTX, was also seen in some of the patients. Significant complications such as rituximab-associated lung injury (RALI), acute tubular necrosis, and central nervous system(CNS) malignancy were also observed in our case series.

CONCLUSIONS

Rituximab can be used with caution as a treatment for recFSGS. Efficacy is variable from none to complete response. Even partial reduction in proteinuria is of benefit in prolonging the life of the allograft. Long-term, multicenter studies are needed to prove its sustained efficacy in those who respond and to monitor for serious adverse effects.

Rituximab therapy prevents focal and segmental glomerulosclerosis recurrence after a second renal transplantation

Preventive treatment of focal and segmental glomerulosclerosis (FSGS) allograft recurrence in high risk recipients having a prior history of graft loss caused by FSGS recurrence is still a challenging question. We retrospectively identified four patients who underwent a second renal transplantation because of recurrent FSGS and who received Rituximab therapy as a prophylactic treatment. Loss of their first allograft was directly related to an early (<3 months) recurrence of FSGS that was either resistant to plasmapheresis therapy in two cases or had escaped to this therapeutic management in the two others. After the second renal transplantation, all patients were free of FSGS recurrence during follow-ups that were between 12 and 54 months long. These preliminary results demonstrate for the first time that Rituximab therapy may constitute an attractive prophylactic option for patients being considered for a second renal transplantation because of recurrent FSGS in their first graft.

Rituximab targets podocytes in recurrent focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is a glomerular disease characterized by proteinuria, progression to end-stage renal disease, and recurrence of proteinuria after kidney transplantation in about one-third of patients. It has been suggested that rituximab might treat recurrent FSGS through an unknown mechanism. Rituximab not only recognizes CD20 on B lymphocytes, but might also bind sphingomyelin phosphodiesterase acid-like 3b (SMPDL-3b) protein and regulate acid sphingomyelinase (ASMase) activity. We hypothesized that rituximab prevents recurrent FSGS and preserves podocyte SMPDL-3b expression. We studied 41 patients at high risk for recurrent FSGS, 27 of whom were treated with rituximab at time of kidney transplant. SMPDL-3b protein, ASMase activity, and cytoskeleton remodeling were studied in cultured normal human podocytes that had been exposed to patient sera with or without rituximab. Rituximab treatment was associated with lower incidence of posttransplant proteinuria and stabilization of glomerular filtration rate. The number of SMPDL-3b(+) podocytes in postreperfusion biopsies was reduced in patients who developed recurrent FSGS. Rituximab partially prevented SMPDL-3b and ASMase down-regulation that was observed in podocytes treated with the sera of patients with recurrent FSGS. Overexpression of SMPDL-3b or treatment with rituximab was able to prevent disruption of the actin cytoskeleton and podocyte apoptosis induced by patient sera. This effect was diminished in cultured podocytes where SMPDL-3b was silenced. Our study suggests that treatment of high-risk patients with rituximab at time of kidney transplant might prevent recurrent FSGS by modulating podocyte function in an SMPDL-3b-dependent manner.

Rituximab's new therapeutic target: the podocyte actin cytoskeleton

Therapeutic off-target activities are well recognized for small-molecule drugs. In contrast, monoclonal antibodies (mAbs) traditionally are believed to act specifically and lack off-target therapeutic effects. In this issue of Science Translational Medicine, Fornoni et al. show therapeutic benefit, through an off-target-mediated mechanism, of the mAb drug rituximab in recurrent focal segmental glomerulosclerosis (FSGS) after kidney transplantation. These data shed new light on FSGS pathogenesis and suggest new therapeutic interventions for proteinuric diseases.

Preemptive plasmapheresis and recurrence of focal segmental glomerulosclerosis in pediatric renal transplantation

  FSGS has a high recurrence rate after renal transplantation. To examine the effects of the use of preemptive and post-transplant PP on recurrence and graft outcome, we conducted a retrospective study on 34 pediatric patients (mean age 13±5 yr) with biopsy-proven pretransplant FSGS and who underwent a renal transplantation between 1996 and 2007. Recurrence was defined as a serum albumin level of <3.0g/L in the presence of nephrotic-range proteinuria (>40mg/m(2) /h). Total response to PP therapy was defined as the resolution of the nephrotic-range proteinuria and partial response as persistent proteinuria despite PP but not in the nephrotic range. Fifteen patients received a LD renal transplantation and 19 patients received a DD renal transplantation. Nineteen patients received CsA and 14 patients received tacrolimus. Nineteen patients (56%) had FSGS recurrence. There was no difference in the recurrence rate between patients receiving CsA vs. tacrolimus. Among the 15 LD patients, 13 received preemptive PP (1-10 sessions) and seven patients (47%) had subsequent FSGS recurrence. Among the 19 DD patients, four received preemptive PP and 12 (63%) had FSGS recurrence. The number of preemptive PP did not affect the recurrence rate. In a group of patients with a previous graft loss secondary to recurrence, the rate of recurrence was lower than expected (40%) and two of the three patients who did not recur had three or more sessions of preemptive PP. Of the 19 patients with recurrence, 17 were treated with PP therapy and 88% of the patients fully or partially responded. Only five patients had graft loss at three yr post-transplant: two from FSGS recurrence and three from non-compliance. These results suggest that preemptive PP does not decrease the rate of recurrence after transplantation but might be beneficial in treating high-risk patients with documented recurrence. Patients with FSGS recurrence post-transplant can achieve good graft survival with both LD and DD transplantation.

Circulating urokinase receptor as a cause of focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is a cause of proteinuric kidney disease, compromising both native and transplanted kidneys. Treatment is limited because of a complex pathogenesis, including unknown serum factors. Here we report that serum soluble urokinase receptor (suPAR) is elevated in two-thirds of subjects with primary FSGS, but not in people with other glomerular diseases. We further find that a higher concentration of suPAR before transplantation underlies an increased risk for recurrence of FSGS after transplantation. Using three mouse models, we explore the effects of suPAR on kidney function and morphology. We show that circulating suPAR activates podocyte β(3) integrin in both native and grafted kidneys, causing foot process effacement, proteinuria and FSGS-like glomerulopathy. Our findings suggest that the renal disease only develops when suPAR sufficiently activates podocyte β(3) integrin. Thus, the disease can be abrogated by lowering serum suPAR concentrations through plasmapheresis, or by interfering with the suPAR-β(3) integrin interaction through antibodies and small molecules targeting either uPAR or β(3) integrin. Our study identifies serum suPAR as a circulating factor that may cause FSGS.

Treatment of recurrent focal segmental glomerulosclerosis in pediatric kidney transplant recipients: effect of rituximab

Recurrence of focal segmental glomerulosclerosis (FSGS) after renal transplantation is a complication that often leads to graft loss. There is no consensus on the optimal treatment of recurrent FSGS. Rituximab, a monoclonal antibody to CD20, may be a useful treatment of this complication. Methods. We report four pediatric cases of recurrent FSGS treated with rituximab and plasmapheresis. Results. Four children (2M/2F), age 15.3 ± 2.6, with recurrent FSGS posttransplant were identified. Four doses of rituximab were administered 171 ± 180 days posttransplant and 114 ± 169 days after the start of plasmapheresis. Three children responded with complete remission, one of whom relapsed after four months. One child had a partial response with a decrease in proteinuria that was not sustained. No adverse side effects were reported during treatment or followup (mean 22.5 months). Conclusions. Rituximab is a safe and well-tolerated ancillary treatment for recurrent FSGS in pediatric patients in conjunction with plasmapheresis.

Posttransplant recurrence of primary glomerulonephritis

All forms of primary GN may recur after kidney transplantation and potentially jeopardize the survival of the graft. IgA nephritis (IgAN) may recur in approximately one third of patients, more frequently in younger patients and in those with a rapid progression of the original disease. However, with the exception of few patients with rapid progression, there is no evidence that recurrence of IgAN has a deleterious effect on graft survival at least up to 10 years. Recurrence of focal segmental glomerulosclerosis (FSGS) is often associated with nephrotic proteinuria and is more frequent in children, in patients with rapid progression of the original disease, and in those who lost a previous transplant from recurrence. The natural course of recurrent FSGS is usually unfavorable. Early and intensive plasmapheresis may obtain complete or partial response in several patients. Good results have also been reported with rituximab. Idiopathic membranous nephropathy (IMN) may recur in 30% to 40% of patients. The graft survival in patients with IMN is not different than that of patients with other renal diseases. Good results with rituximab have been reported. Membranoproliferative GN (MPGN) may recur in 27% to 65% of patients. The recurrence is more frequent and the prognosis is more severe in type II MPGN. Although recurrent GN is relatively frequent and may worsen the outcome of renal allografts in some patients, its effect is diluted by several other risk-factors that may have a greater effect than recurrent GN on the long-term graft survival.

Recurrence of focal segmental glomerulosclerosis in renal allograft: an in-depth review

Focal segmental glomerulosclerosis is a major cause of chronic kidney disease requiring transplantation in children. Recurrence rate in the renal allograft transplantation is as high as 50%. Recurrence of FSGS is associated with renal dysfunction and early graft loss. To date, there is no established therapy for recurrent FSGS after renal transplant. We have reviewed the current English literature in order to summarize current practices with emphasis on graft outcome. We conclude that despite multiple approaches to the post transplant management of recurrent FSGS, none have been shown to be consistently beneficial. Currently, pheresis combined with high dose anti-calcineurin with or without rituximab seems to be the most promising. Further controlled studies are needed to define the optimal therapeutic regimens to treat recurrent of FSGS.

Long-term outcome of focal segmental glomerulosclerosis after pediatric renal transplantation

Recurrence of focal segmental glomerulosclerosis (FSGS) after renal transplantation can limit graft survival. Despite new immunosuppressive agents, the incidence of recurrence remains relatively high. To identify risk factors for recurrence and efficacy of treatment, we reviewed the outcome of 23 grafts in 16 children with FSGS who had undergone transplantation between 1985 and 2007 at La Paz Children's Hospital. Recurrence was 56.3% after the first transplantation. We did not find significant differences in age at diagnosis, age at transplantation, age at end-stage renal disease (ESRD), progression to ESRD, bilateral nephrectomy of native kidneys prior to transplantation, use of induction therapy or of different immunosuppressive regimens between patients with and without recurrence. Plasmapheresis (PP) was carried out in seven of nine patients who had suffered recurrence, achieving remission in six of them. One patient received high doses of cyclosporin (CsA) and plasmapheresis, attaining remission. Graft survival was lower (P = 0.043) in patients with FSGS than in those with other ESRD etiologies (first year 75% vs 91%; fifth year 44% vs 78%). Recurrence of FSGS limited graft survival (first year 66% vs 85%; third year 20% vs 68%) (P = 0.07). In our experience, PP can be effective in treating FSGS recurrence, although its effect on long-term graft survival seems more limited.

Kidney transplantation for primary focal segmental glomerulosclerosis: outcomes and response to therapy for recurrence

BACKGROUND

For a subset of adults and children with primary focal segmental glomerulosclerosis (FSGS), proteinuria and renal dysfunction recur after kidney transplantation (KTx). Predicting recurrence and response to plasmapheresis (PP) or other interventions remains problematic.

METHODS

The prevalence, recurrence rate, outcomes, and treatment responses of patients with FSGS were determined among 1573 KTx recipients. Although 5.0% carried some diagnosis of FSGS, only 1.9% (n=30) met strict diagnostic criteria for primary FSGS including biopsy-proven FSGS, lack of secondary factors, negative family history, and progression to end-stage renal disease within 10 years.

RESULTS

Of these, 47% had recurrent FSGS compared with 8% of those not meeting strict criteria (P<0.001). Recurrence was more common in children compared with adults (86% vs. 35%, P=0.01). Graft survival was lower for recipients with primary FSGS compared with all others and inferior graft survival was attributable to recurrent FSGS. Fourteen patients received PP preemptively (pre-KTx) or therapeutically (post-KTx) for recurrent disease. Four pediatric patients additionally received anti-CD20 (rituximab) therapy. Of the different treatment approaches, only PP combined with rituximab was associated with prolonged remission of proteinuria.

CONCLUSIONS

The results indicate that patients at high risk for FSGS recurrence can be identified and may benefit from carefully planned peritransplant interventions.

Long-term outcome after renal transplantation in childhood

The purpose of this article is to review: 1. Factors influencing long-term outcome data after transplantation 2. Patient survival overall, the effect of recipient age and donor type, causes of death, comparison of mortality after transplantation with that on dialysis, and effect of pre-emptive transplantation and race 3. Transplant survival overall, and the effect of recipient and donor age, donor type, pre-emptive transplantation, recurrent diseases, human leukocyte antigen (HLA) matching, immunosuppression, concordance, hypertension, bladder dynamics and type of donor nephrectomy 4. Final height and obesity 5. Psycho-social outcome.

Outcome of living donor renal allograft survival in children with focal segmental glomerulosclerosis

FSGS is the most frequent GN that may recur in a renal allograft. Compared with adults, the impact of FSGS on graft survival appears to be more significant in children. Thus we decided to assess graft survival and complications after renal transplantation in children with FSGS. Outcome of renal transplantation in 25 children with FSGS who received a renal transplant at Labafi Nejad Hospital was studied and compared with 75 patients as a control group. The mean follow-up duration was 68.16 (s.d. = 41.93) months. Other than demographics, variables such as DGF, acute rejection, number of acute rejection episodes, and graft failure in both groups were evaluated. Acute rejection was seen in 22/25 (88%) of FSGS group, compared to 40/75 (53.3%) in the control group. This difference was statistically significant (p = 0.001). DGF was seen in 4/25 (16%) and 13/75 (17.3%) in the FSGS and control groups, respectively (p = N.S.). The mean graft survival time was 115.61 (s.e.m. = 12.56) and 155.56 (s.e.m. = 7.16) month in FSGS and control group, respectively (p = N.S.). We demonstrated that graft function and survival were not significantly different in the FSGS and control patients. However, acute rejection episodes were more common in FSGS patients but without a significant impact on graft survival.

Demographics and response to therapeutic plasma exchange in pediatric renal transplantation for focal glomerulosclerosis: a single center experience

Recurrence of FSGS following renal transplantation in pediatric patients is reported as 20-57%. Records of 37 pediatric patients transplanted for FSGS between 1990 and 2005 at a single center were reviewed. Recurrence of disease was assessed by nephrotic range proteinuria and/or FSGS on biopsy. Response to TPE was defined as urine protein to creatinine ratio <0.2. Forty-nine percent of patients were African American, 38% were Caucasian. Fifty-four percent received kidneys from deceased donors and 46% from live donors. Seven patients received preemptive TPE prior to transplantation. Two of these seven patients recurred in the transplanted kidney (28%). Recurrent FSGS occurred in 16 of 37 patients (46%), all of whom received TPE. Recurrence occurred within one month in 12 of 37 patients (32%); eight remitted with TPE (67%). Four of 12 patients failed to respond to TPE. Four of 37 patients (14%) recurred more than one month after transplantation and underwent TPE; three-fourths of patients remitted (75%). Twenty-one of 37 patients (54%) did not recur. One and five yr graft survivals were 84% and 67%, respectively. Median graft survival was 6.7 yr (5.2-10.3). Despite recurrence, FSGS patients can achieve sustained graft function.