Recurrent focal glomerulosclerosis in pediatric renal allografts: the Miami experience

Post-transplant recurrence of focal segmental glomerular sclerosis: consensus statements

Focal segmental glomerular sclerosis (FSGS) is 1 of the primary causes of nephrotic syndrome in both pediatric and adult patients, which can lead to end-stage kidney disease. Recurrence of FSGS after kidney transplantation significantly increases allograft loss, leading to morbidity and mortality. Currently, there are no consensus guidelines for identifying those patients who are at risk for recurrence or for the management of recurrent FSGS. Our work group performed a literature search on PubMed/Medline, Embase, and Cochrane, and recommendations were proposed and graded for strength of evidence. Of the 614 initially identified studies, 221 were found suitable to formulate consensus guidelines for recurrent FSGS. These guidelines focus on the definition, epidemiology, risk factors, pathogenesis, and management of recurrent FSGS. We conclude that additional studies are required to strengthen the recommendations proposed in this review.

The podocyte: glomerular sentinel at the crossroads of innate and adaptive immunity

Focal segmental glomerulosclerosis (FSGS) is a common glomerular disorder that manifests clinically with the nephrotic syndrome and has a propensity to recur following kidney transplantation. The pathophysiology and therapies available to treat FSGS currently remain elusive. Since the podocyte appears to be the target of apparent circulating factor(s) that lead to recurrence of proteinuria following kidney transplantation, this article is focused on the podocyte. In the context of kidney transplantation, the performance of pre- and post-reperfusion biopsies, and the establishment of in vitro podocyte liquid biopsies/assays allow for the development of clinically relevant studies of podocyte biology. This has given insight into new pathways, involving novel targets in innate and adaptive immunity, such as SMPDL3b, cGAS-STING, and B7-1. Elegant experimental studies suggest that the successful clinical use of rituximab and abatacept, two immunomodulating agents, in our case series, may be due to direct effects on the podocyte, in addition to, or perhaps distinct from their immunosuppressive functions. Thus, tissue biomarker-directed therapy may provide a rational approach to validate the mechanism of disease and allow for the development of new therapeutics for FSGS. This report highlights recent progress in the field and emphasizes the importance of kidney transplantation and recurrent FSGS (rFSGS) as a platform for the study of primary FSGS.

Benefit of B7-1 staining and abatacept for treatment-resistant post-transplant focal segmental glomerulosclerosis in a predominantly pediatric cohort: time for a reappraisal

BACKGROUND

Primary FSGS manifests with nephrotic syndrome and may recur following KT. Failure to respond to conventional therapy after recurrence results in poor outcomes. Evaluation of podocyte B7-1 expression and treatment with abatacept (a B7-1 antagonist) has shown promise but remains controversial.

METHODS

From 2012 to 2020, twelve patients developed post-KT FSGS with nephrotic range proteinuria, failed conventional therapy, and were treated with abatacept. Nine/twelve (< 21 years old) experienced recurrent FSGS; three adults developed de novo FSGS, occurring from immediately, up to 8 years after KT. KT biopsies were stained for B7-1.

RESULTS

Nine KTRs (75%) responded to abatacept. Seven of nine KTRs were B7-1 positive and responded with improvement/resolution of proteinuria. Two patients with rFSGS without biopsies resolved proteinuria after abatacept. Pre-treatment UPCR was 27.0 ± 20.4 (median 13, range 8-56); follow-up UPCR was 0.8 ± 1.3 (median 0.2, range 0.07-3.9, p < 0.004). Two patients who were B7-1 negative on multiple KT biopsies did not respond to abatacept and lost graft function. One patient developed proteinuria while receiving belatacept, stained B7-1 positive, but did not respond to abatacept.

CONCLUSIONS

Podocyte B7-1 staining in biopsies of KTRs with post-transplant FSGS identifies a subset of patients who may benefit from abatacept. A higher resolution version of the Graphical abstract is available as Supplementary information.

Focal segmental glomerulosclerosis: Risk for recurrence and interventions to optimize outcomes following recurrence

BACKGROUND

FSGS is a common indication for kidney transplant with a high-risk of posttransplant recurrence.

METHODS

In this review, we summarize current knowledge about FSGS recurrence after kidney transplantation, including epidemiology, pretransplant planning, posttransplant management, and investigational treatments.

RESULTS

FSGS recurs in 14%-60% of first transplants, likely associated with a circulating permeability factor. Pretransplant counseling regarding recurrence is critical, and patients with FSGS should undergo pretransplant genetic screening. Rapid progression to ESKD, initial steroid responsiveness, younger age at diagnosis, race/ethnicity, and mesangial hypercellularity or minimal change histology on native biopsy may be associated with recurrence. Living donation is not contraindicated but does not result in improved graft survival relative to deceased donation. Pretransplant nephrectomy may be performed for a variety of reasons, but does not decrease recurrence. Pretransplant therapy with rituximab and/or PE is understudied but not clearly effective at preventing recurrence. Patients with FSGS typically present early with rapid-onset severe proteinuria. Diagnosis can be confirmed by biopsy showing foot process effacement; typical FSGS lesions are not seen on light microscopy in the early stages. There is no established effective treatment for recurrent FSGS, but renin-angiotensin-aldosterone system inhibition and extracorporeal therapies, including PE and IA, are most commonly used. Adjunct or alternative therapies may include rituximab, lipopheresis, and cyclosporine.

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.

Post-transplant recurrence of steroid resistant nephrotic syndrome in children: the Italian experience

BACKGROUND

Steroid resistant nephrotic syndrome (SRNS) is a frequent cause of end stage renal disease in children and post-transplant disease recurrence is a major cause of graft loss.

METHODS

We identified all children with SRNS who underwent renal transplantation in Italy, between 2005 and 2017. Data were retrospectively collected for the presence of a causative gene mutation, sex, histology, duration of pre-transplant dialysis, age at onset and transplant, HLA matching, recurrence, therapy for recurrence, and graft survival.

RESULTS

101 patients underwent a first and 22 a second renal transplant. After a median follow-up of 58.5 months, the disease recurred on the first renal transplant in 53.3% of patients with a non-genetic and none with a genetic SRNS. Age at transplant > 9 years and the presence of at least one HLA-AB match were independent risk factors for recurrence. Duration of dialysis was longer in children with relapse, but did not reach statistical significance. Overall, 24% of patients lost the first graft, with recurrence representing the commonest cause. Among 22 patients who underwent a second transplant, 5 suffered of SRNS recurrence. SRNS relapsed in 5/9 (55%) patients with disease recurrence in their first transplant and 2 of them lost the second graft.

CONCLUSIONS

Absence of a causative mutation represents the major risk factor for post-transplant recurrence in children with SRNS, while transplant can be curative in genetic SRNS. A prolonged time spent on dialysis before transplantation has no protective effect on the risk of relapse and should not be encouraged. Retransplantation represents a second chance after graft loss for recurrence.

Pre-emptive rituximab in focal and segmental glomerulosclerosis patients at risk of recurrence after kidney transplantation

Background

The recurrence of proteinuria after kidney transplantation (KT) is a characteristic complication of focal segmental glomerulosclerosis (FSGS). It has been suggested that pre-emptive rituximab might prevent recurrences in patients at risk, but there is no agreement about which factors might help to identify such patients.

Methods

We studied 93 kidney transplants with biopsy-proven idiopathic FSGS in order to analyse if preventive rituximab treatment could decrease recurrences in patients at risk.

Results

Fifteen patients (16.1%) presented a recurrence after KT, but when we restricted the analysis to the 34 patients presenting nephrotic syndrome at primary disease onset, the recurrence diagnosis rate increased to 44.1%. All patients with recurrence had complete nephrotic syndrome at the time of diagnosis. After multivariate adjustment, the only significant risk factor for recurrence was the presence of complete nephrotic syndrome at diagnosis. Twelve of the 34 patients at risk for recurrence received rituximab at the time of transplantation. Clinical and analytical characteristics were similar in all patients at risk. The number of recurrences was similar among treated (50%) and non-treated patients (40.9%).

Conclusions

Nephrotic syndrome with hypoalbuminaemia at diagnosis is the most important feature to identify patients at risk of recurrence. Our data suggest that pre-emptive rituximab is not effective to prevent FSGS recurrences.

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.

The elusive podocyte crossmatch for recurrent focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis is a glomerular disorder with a high rate of recurrence. Although kidney biopsies remain the gold standard to diagnose recurrent focal segmental glomerulosclerosis, non-invasive prognostic assays could facilitate preventive treatments and offer insight into disease pathogenicity and heterogeneity. Srivastava et al. describe a simple, cell-based assay to predict recurrence of focal segmental glomerulosclerosis. Although the study needs to be optimized and validated, its novelty is that it does not depend on the specificity of a given permeability factor.

Long-Term Follow-up Results of Renal Transplantation in Pediatric Patients With Focal Segmental Glomerulosclerosis: A Single-Center Experience

INTRODUCTION AND AIM

Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage renal disease in children. We analyzed the long-term outcome of pediatric patients with FSGS undergoing renal transplantation. The objective of the study is to report the experience of a single center and determine the incidence of recurrence, rejection, graft loss, and related risk factors.

MATERIALS AND METHOD

This retrospective cohort study was performed between 1991 and 2018. Thirty patients with a pathologic diagnosis of primary FSGS were included in the study. The patients were diagnosed with FSGS according to histologic features in biopsies.

RESULTS

Twenty-one of the donors were deceased (70%) and 9 were alive (30%). FSGS recurred in only 2 patients. Graft loss occurred in 6 patients (20%). The causes of graft loss were chronic rejection in 4 patients and acute rejection in 2. Our graft survival rate was 100% at 1 year, 91% at 5 years, 80% at 10 years, 70% at 15 years, and 42% at 20 years. Five- and 10-year graft survival rates were 83% and 83% in living donors and 94% and 79% in deceased donors, respectively. According to Kaplan-Meier analysis, there was no statistically significant difference in terms of graft survival between living and deceased donors.

CONCLUSION

This study, with its contribution to literature in terms of long follow-up of FSGS patients from childhood to adulthood, is important. However, further studies are required.

Anti-CD20 Blocker Rituximab in Kidney Transplantation

Rituximab is a chimeric anti-CD20 monoclonal protein used in various clinical scenarios in kidney transplant recipients. However, its evidence-based use there remains limited due to lack of controlled studies, limited sample size, short follow-up and poorly defined endpoints. Rituximab is indicated for CD20+ posttransplant lymphoproliferative disorder. It may be beneficial for treating recurrent membranous nephropathy and recurrent allograft antineutrophilic cytoplasmic antibody vasculitis and possibly for recurrent focal segmental glomerulosclerosis. Rituximab, in combination with IVIg/plasmapheresis, appears to decrease antibody level and increase the odds of transplantation in sensitized recipients. The role of Rituximab in ABOi transplant remains unclear, as similar outcomes are achieved without its use. Rituximab is not efficacious in antibody-mediated rejection/chronic antibody-mediated rejection. Strict randomized control trials are necessary to elucidate its true role in these settings.

Recurrence of primary glomerulonephritis: Review of the current evidence

In view of the availability of new immunosuppression strategies, the recurrence of allograft glomerulonephritis (GN) are reported to be increasing with time post transplantation. Recent advances in understanding the pathogenesis of the GN recurrent disease provided a better chance to develop new strategies to deal with the GN recurrence. Recurrent GN diseases manifest with a variable course, stubborn behavior, and poor response to therapy. Some types of GN lead to rapid decline of kidney function resulting in a frustrating return to maintenance dialysis. This subgroup of aggressive diseases actually requires intensive efforts to ascertain their pathogenesis so that strategy could be implemented for better allograft survival. Epidemiology of native glomerulonephritis as the cause of end-stage renal failure and subsequent recurrence of individual glomerulonephritis after renal transplantation was evaluated using data from various registries, and pathogenesis of individual glomerulonephritis is discussed. The following review is aimed to define current protocols of the recurrent primary glomerulonephritis therapy.

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.

Optimal management of primary focal segmental glomerulosclerosis in adults

Focal segmental glomerulosclerosis (FSGS) is a frequent glomerular kidney disease that is revealed by proteinuria or even nephrotic syndrome. A diagnosis can be established from a kidney biopsy that shows focal and segmental glomerulosclerosis. This histopathological lesion may be caused by a primary podocyte injury (idiopathic FSGS) but is also associated with other pathologies (secondary FSGS). The first-line treatment for idiopathic FSGS with nephrotic syndrome is a prolonged course of corticosteroids. However, steroid resistance or steroid dependence is frequent, and despite intensified immunosuppressive treatment, FSGS can lead to end-stage renal failure. In addition, in some cases, FSGS can recur on a graft after kidney transplantation: an unidentified circulating factor may be implicated. Understanding of its physiopathology is unclear, and it remains an important challenge for the scientific community to identify a specific diagnostic biomarker and to develop specific therapeutics. This study reviews the treatment of primary FSGS and the recurrence of FSGS after kidney transplantation in adults.

FSGS Recurrence in Adults after Renal Transplantation

Recurrence of focal segmental glomerulosclerosis (FSGS) in the allograft occurs in 30–50% of patients, and it is associated with poor renal allograft survival. Major risk factors for recurrence are younger age at diagnosis, rapid progression to end-stage renal disease, white race, and the loss of previous allografts due to recurrence. Recent data support the hypothesis that circulating permeability factors play a crucial role in podocyte injury and progression of FSGS. Due to lack of controlled trials, the management of recurrent FSGS is inconsistent and highly empirical. Prophylactic and perioperative treatment with plasmapheresis and high-dose (intravenous) cyclosporine represent the main cornerstones of immunosuppressive therapy. In recent years, therapy with rituximab has shown promising results. Despite evidence of activation of the renin-angiotensin system (RAS) in recurrent FSGS and its association with progression, only limited data exist on the renoprotective role of RAS blockade in this setting. Further well designed studies are needed on pathogenesis risk factors and therapeutical options in FSGS and its recurrence after transplantation.

Outcome of glomerulonephritis in live-donor renal transplant recipients: A single-centre experience

OBJECTIVES

To investigate the frequency and risk factors affecting the incidence of post-transplantation glomerulonephritis (GN) and the impact of GN on the survival of the graft and the patient.

PATIENTS AND METHODS

Patients were classified based on histological findings into three groups. Graft survival was ascertained using the Kaplan-Meier method and significance calculated using log-rank tests. For multivariate analysis the Cox model was used.

RESULTS

Transplant glomerulopathy was the most prevalent glomerular disease in our series followed by recurrent GN and lastly de novo GN. In all, 50% of the de novo GN group had diabetes. The worst graft outcomes were in the recurrent GN group (P = 0.044). Multivariate analysis revealed ageing of the graft and mammalian target of rapamycin (mTOR) immunosuppression as risk factors for development of GN. While, the age of the recipient and donor, anti-lymphocyte globulin induction therapy, and acute rejection were risk factors for poor graft outcomes.

CONCLUSIONS

GN is an important issue after transplantation. Tracking the incidence and progression of histological findings in the graft may help to guide proper management and improve graft outcome.

Recurrent focal segmental glomerulosclerosis after kidney transplantation

Focal segmental glomerulosclerosis (FSGS) is an important cause of glomerular disease in children and adolescents and nearly 50 % of affected patients will progress to end-stage kidney disease over a 5 to 10-year period. Unfortunately, there is no established treatment for disease in the native kidney. Moreover, up to 55 % of patients develop recurrent disease after receiving a kidney transplant, with a substantially higher risk in patients who have already experienced recurrent disease in a prior transplant. A number of clinical and laboratory factors have been identified as risk factors for this complication. In addition, new investigations into podocyte biology and circulating permeability factors have shed light on the cause of recurrent the disease. While a number of novel therapeutic agents have been applied in the management of this problem, there still is no proven treatment. In this review, we summarize recent advances in the epidemiology, pathophysiology, and treatment of recurrent FSGS in pediatric patients who have received a kidney transplant.

Management of proteinuria in the transplanted patient

Proteinuria is a relatively frequent complication in children after renal transplantation (40-80 %). It is usually mild and non-nephrotic in nature and predominantly tubular in origin. The major causes of post-transplant proteinuria are recurrence of primary glomerulonephritis [mostly focal segmental glomerulosclerosis (FSGS)], rejection (acute and chronic), mTOR inhibitors or hypertension. Proteinuria is a risk factor for graft loss and patient death in adults, and even a mild proteinuria (0.1-0.2 g/day) is associated with impaired graft and patient survival. In children, proteinuria seems to be associated with graft but not patient survival. Proteinuria (protein/creatinine ratio) should be assessed regularly in all children. In children with prior chronic kidney disease due to idiopathic FSGS, proteinuria should be assessed daily during the first month after transplantation to enable early diagnosis of recurrence. The cause of proteinuria should be identified, and graft biopsy should be considered in children with unexplained proteinuria, especially with new onset proteinuria or deterioration of previously mild proteinuria. Treatment must be primarily targeted at the cause of proteinuria, and in normotensive children symptomatic antiproteinuric therapy with angiotensin-converting enzyme inhibitors/angiotensin II receptor antagonists should also be initiated. Other antihypertensive drugs should be used to achieve target blood pressure of <75th percentile. Target proteinuria should be <20 mg/mmol creatinine.

Tandem hemodialysis and plasma exchange

The combination of hemodialysis and plasma exchange as one tandem procedure was first described in 1999 by Siami et al. (ASAIO J 45:229-233), but larger pediatric case series were not described until 2012. Even in adults, there are only limited case series. If performed in sequence, up to 8 h of treatment time may be required. With the use of the tandem procedure in stable patients, the same procedures can be completed during the same time as a routine hemodialysis, which is more convenient for patients and may reduce healthcare costs. Little is known about the utilization of the combination of hemodialysis and plasma exchange in children. The purpose of this review is to summarize the adult and scarce pediatric experience. The results of a survey carried out by the authors using the Internet listserver "PedNeph" to obtain an overview of the current practice patterns of pediatric nephrologists are also presented.

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.

Initial steroid sensitivity in children with steroid-resistant nephrotic syndrome predicts post-transplant recurrence

Of children with idiopathic nephrotic syndrome, 10%-20% fail to respond to steroids or develop secondary steroid resistance (termed initial steroid sensitivity) and the majority progress to transplantation. Although 30%-50% of these patients suffer disease recurrence after transplantation, with poor long-term outcome, no reliable indicator of recurrence has yet been identified. Notably, the incidence of recurrence after transplantation appears reduced in patients with steroid-resistant nephrotic syndrome (SRNS) due to monogenic disorders. We reviewed 150 transplanted patients with SRNS to identify biomarkers that consistently predict outcome of SRNS after transplantation. In all, 25 children had genetic or familial SRNS and did not experience post-transplant recurrence. We reviewed phenotypic factors, including initial steroid sensitivity, donor type, age, ethnicity, time to ESRD, and time on dialysis, in the remaining 125 children. Of these patients, 57 (45.6%) developed post-transplant recurrence; 26 of 28 (92.9%) patients with initial steroid sensitivity recurred after transplantation, whereas only 26 of 86 (30.2%) patients resistant from the outset recurred (odds ratio, 30; 95% confidence interval, 6.62 to 135.86; P<0.001). We were unable to determine recurrence in two patients (one with initial steroid sensitivity), and nine patients did not receive initial steroids. Our data show that initial steroid sensitivity is highly predictive of post-transplant disease recurrence in this pediatric patient population. Because a pathogenic circulating permeability factor in nephrotic syndrome remains to be confirmed, we propose initial steroid sensitivity as a surrogate marker for post-transplant recurrence.

Issues in solid-organ transplantation in children: translational research from bench to bedside

In this review, we identify important challenges facing physicians responsible for renal and cardiac transplantation in children based on a review of the contemporary medical literature. Regarding pediatric renal transplantation, we discuss the challenge of antibody-mediated rejection, focusing on both acute and chronic antibody-mediated rejection. We review new diagnostic approaches to antibody-mediated rejection, such as panel-reactive antibodies, donor-specific cross-matching, antibody assays, risk assessment and diagnosis of antibody-mediated rejection, the pathology of antibody-mediated rejection, the issue of ABO incompatibility in renal transplantation, new therapies for antibody-mediated rejection, inhibiting of residual antibodies, the suppression or depletion of B-cells, genetic approaches to treating acute antibody-mediated rejection, and identifying future translational research directions in kidney transplantation in children. Regarding pediatric cardiac transplantation, we discuss the mechanisms of cardiac transplant rejection, including the role of endomyocardial biopsy in detecting graft rejection and the role of biomarkers in detecting cardiac graft rejection, including biomarkers of inflammation, cardiomyocyte injury, or stress. We review cardiac allograft vasculopathy. We also address the role of genetic analyses, including genome-wide association studies, gene expression profiling using entities such as AlloMap®, and adenosine triphosphate release as a measure of immune function using the Cylex® ImmuKnow™ cell function assay. Finally, we identify future translational research directions in heart transplantation in children.

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.

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 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.

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.

Flowcytometric analysis of lymphocytapheresis in a patient with recurrent FSGS after renal transplant

Frequently, focal segmental glomerulosclerosis (FSGS) recurs after renal transplantation, resulting in poor graft survival. Pathological mechanisms of the recurrence are still unknown, but both B and T cell disorders are suspected based on much evidence. This supports theoretical benefits using plasma exchange (PE) and lymphocytapheresis (LCAP). A renal transplant was performed for a 35-year-old woman, who suffered steroid-resistant FSGS and developed to chronic kidney disease stage 5D at 31 years old. We treated the patient with recurrent FSGS by LACP and examined whether peripheral neutrophils were dynamically changed after the therapy. Further, we performed flowcytometric analysis to examine lymphocyte fractions before and after LCAP. The decrease of helper (CD4 positive) and memory (CD4 and CD45RO positive) T cells was prominent after LCAP. Although B cells were at the nadir because of rituximab treatment, LCAP also decreased peripheral B cells. These suggest that LCAP has the potential to suppress the activities of recurrent FSGS after renal transplant.

Two decades of pediatric kidney transplantation in a multi-ethnic cohort

This study evaluated a 20-yr experience in kidney transplantation in children from a predominantly Hispanic community. A retrospective analysis was carried out in children who received kidney transplants from 1985 to 2005. Of 124 kidney transplants, 81 (65%) were from LD. Racial distribution was Hispanic (48%), followed by AA (24%) and Caucasian (26%). First yr allograft survival was similar in LD and DD and significantly better in LD until seven yr post transplant. eGFR <60 mL/min/1.73 m(2) at one yr post transplant was associated with a median allograft survival of 3.3 yr, compared to 16 yr in those with eGFR > or = 60 mL/min/1.73 m(2) (p < 0.0001). Graft loss in the first five yr was from non-adherence, recurrence of disease, and infections. Those of AA race were more likely to receive a DD and have low socioeconomic status and the poorest median allograft survival compared to Hispanics and Caucasians (6 vs. > or =15 yr; p < 0.001). In conclusion, this predominantly Hispanic cohort emphasizes the disadvantaged profile of AAs compared to other racial groups. Strategies to improve supportive services and living donations in minority populations need to be developed. Long-term renal allograft survival is achievable if GFR is maintained >60 mL/min/1.73 m(2).

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.

Long-term outcome of renal transplantation in adults with focal segmental glomerulosclerosis

SUMMARY

Little information is available about the long-term results of kidney transplantation in adults with focal segmental glomerulosclerosis (FSGS). The outcomes of 52 renal transplants performed between 1988 and 2008 in 47 adults with FSGS were compared with those of 104 matched controls (median follow-up 93.4 vs. 109.4 months respectively). At 15 years, patient survival was 100% and graft survival 56% in FSGS patients vs. 88.3% and 64% respectively in controls (P = NS). FSGS recurred in 12 out of 52 grafts (23%) and led to graft failure in seven within 10 months (median). In the other five cases, proteinuria remitted and grafts are functioning 106 months (median) after transplantation. A second recurrence developed in five out of eight re-transplanted patients (62.5%) who lost their first graft because of recurrence; only one graft was lost. Patients with recurrence were more frequently male subjects (83% vs. 40%, P = 0.02), younger at diagnosis of FSGS (16.3 +/- 6.8 vs. 24.1 +/- 11.5 years, P = 0.03) and of younger age at transplantation (28.4 +/- 7.8 vs. 35.8 +/- 12.2 years, P = 0.05). Treatment with plasmapheresis plus ACE inhibitors achieved either complete or partial remission in 80% of the cases. Long-term patient and renal allograft survivals of adults with FSGS were comparable to those of controls. Recurrence was more frequent in young patients and in patients who lost a previous graft from recurrence. Graft loss resulting from a second recurrence is lower than expected.

Focal and segmental glomerulosclerosis induced in mice lacking decay-accelerating factor in T cells

Heritable and acquired diseases of podocytes can result in focal and segmental glomerulosclerosis (FSGS). We modeled FSGS by passively transferring mouse podocyte-specific sheep Abs into BALB/c mice. BALB/c mice deficient in the key complement regulator, decay-accelerating factor (DAF), but not WT or CD59-deficient BALB/c mice developed histological and ultrastructural features of FSGS, marked albuminuria, periglomerular monocytic and T cell inflammation, and enhanced T cell reactivity to sheep IgG. All of these findings, which are characteristic of FSGS, were substantially reduced by depleting CD4+ T cells from Daf(-/-) mice. Furthermore, WT kidneys transplanted into Daf(-/-) recipients and kidneys of DAF-sufficient but T cell-deficient Balb/(cnu/nu) mice reconstituted with Daf(-/-) T cells developed FSGS. In contrast, DAF-deficient kidneys in WT hosts and Balb/(cnu/nu) mice reconstituted with DAF-sufficient T cells did not develop FSGS. Thus, we have described what we believe to be a novel mouse model of FSGS attributable to DAF-deficient T cell immune responses. These findings add to growing evidence that complement-derived signals shape T cell responses, since T cells that recognize sheep Abs bound to podocytes can lead to cellular injury and development of FSGS.

Intensive and prolonged treatment of focal and segmental glomerulosclerosis recurrence in adult kidney transplant recipients: a pilot study

No treatment has consistently induced long-term remission of proteinuria in adult patients with focal segmental glomerulosclerosis (FSGS) recurrence after kidney transplantation. We undertook an open-label, nonrandomized pilot trial of intensive and prolonged treatment of FSGS recurrence. Over an 18-month period, 10 adult kidney transplant recipients with FSGS recurrence received concomitantly high-dose steroids, intravenous cyclosporine for 14 days followed by oral cyclosporine therapy, and an intensive and prolonged course of plasma exchanges (PE). We compared this treatment with those of a control group of 19 patients with a FSGS recurrence transplanted between 1997 and 2005. Complete, rapid (mean 23 +/- 7 days) and sustained remission was obtained in 9/10 patients (90%) as opposed to 27% in the control group. At month 3 and month 12, proteinuria was 0.16 g/day (range 0.05-0.3 g/day) and 0.19 g/day (range 0.05-1 g/day) respectively. Only one patient remained in partial remission at month 12 but he had already lost two previous grafts due to FSGS recurrence. PEs were stopped at month 9 in all patients except for the patient with a partial remission who remains PE-dependent. This small pilot study provides very encouraging results demonstrating that this treatment rapidly achieves complete and sustained remission in a high proportion of patients.

Focal segmental glomerular sclerosis in renal transplant recipients: predicting early disease recurrence may prolong allograft function

Recurrence of focal segmental glomerular sclerosis (FSGS) in the allograft following renal transplantation can be graft threatening. To assess risk factors associated with FSGS recurrence, we analyzed 22 patients with FSGS who underwent transplantation between 1996 and 2004. Five patients (Group I, 23%) developed FSGS post-transplantation. Of these patients, 60% had undergone bilateral nephrectomy (BN) for progressive disease compared with none of the patients that were free of recurrence (Group II) (p = 0.0006). Other factors linked with recurrent FSGS were time to first dialysis (Group I: 3.1 +/- 1.1 yr vs. Group II: 11.9 +/- 1.9 yr; p = 0.03), pre-transplant proteinuria (Group I: 7.0 +/- 1.8 g/d vs. Group II: 2.5 +/- 0.7 g/d; p = 0.02), young age at transplantation (p = 0.09) and female sex (Group I: 80% vs. Group II: 24%; p = 0.021). Eighty percent of Group I patients received a living related transplant vs. 24% in Group II (p = 0.021). All grafts continue to function at last follow-up with comparable serum creatinines. Overall, post-transplant FSGS recurrence may be associated with BN, severity of pre-transplant FSGS, female gender, and living donation. These patients should be monitored closely for early recurrence and may benefit from early plasmapheresis to restore and facilitate long-term graft function.

Successful anti-TNFalpha treatment in a child with posttransplant recurrent focal segmental glomerulosclerosis

Posttransplant recurrence of focal and segmental glomulosclerosis (FSGS) occurs in approximately 30% of patients, and remains after uncontrolled despite increased immunosuppression and plasma exchanges (PE) in approximately 30% of cases. New immunosuppressive drugs might then be warranted. We report the case of a 15-year-old boy with FSGS leading to end-stage renal disease (ESRD) who presented with an early posttransplant recurrence of disease. Reinforced immunosuppression and PE resulted in partial and transient disease control, but proteinuria significantly decreased with anti-TNFalpha treatment (infliximab then etanercep). This is the first case report of successful anti-TNFalpha treatment despite a constant high activity of FSGS, as demonstrated by relapse after discontinuation of anti-TNFalpha agents.

Monitoring kidney function and renal disease in children following transplant

This article reviews the currently available tools for measuring glomerular filtration rate (GFR) and early detection of chronic kidney disease in pediatric transplant recipients. GFR measurement remains the mainstay to detect renal dysfunction. Inulin clearance formed the earlier gold standard method to measure GFR. In current clinical practice, it has been replaced by nuclear medicine techniques (51Cr EDTA and 99Tc DTPA isotope clearance studies). GFR estimation based on surrogate markers allows more frequent GFR monitoring in a clinical setting. Serum creatinine has a low sensitivity to detect early renal dysfunction and its muscle mass dependency hampers its clinical utility. The Schwartz formula accounts for age-dependent muscle changes in children, but requires center-specific constants. Cystatin C offers the advantage of a constant production and a higher sensitivity in diagnosing renal dysfunction. Microalbuminuria has been an established screening tool in diabetic renal disease. It offers the advantage of detecting underlying renal damage even before a decrease in GFR. Its diagnostic value in other conditions needs evaluation. Hypertension is known to accelerate the progression of chronic kidney disease. A 24-h ambulatory blood pressure is a useful tool to diagnose hypertension, to quantify blood pressure load and to characterize nocturnal blood pressure dipping. GFR scans, serum creatinine and cystatin C form the cornerstone of currently used tools to evaluate kidney dysfunction.

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.

Induction therapy in pediatric renal transplant recipients: an overview

Induction therapy to prevent the acute rejection of mismatched allografts with the ultimate aim of prolonging the life of the allograft has been the cornerstone of immunosuppression since the introduction of renal transplantation. Agents used for induction therapy have changed over time. Their role in transplantation is expanding to include corticosteroid avoidance and immunosuppression minimization. This review provides an overview of induction therapies for renal transplantation including historic therapies such as total lymphoid irradiation and Minnesota antilymphocyte globulin, and current therapies with polyclonal and monoclonal antibodies and chemical agents, with special emphasis on children. Data from adult studies, and pediatric studies whenever available, are summarized. A brief summary of experimental therapies with fingolimod and belatacept is provided. Historically, induction therapies were targeted at T cells. The role of induction therapies targeted at B cells is emerging in select groups of patients that include highly sensitized recipients and those receiving transplants from blood group incompatible donors. With the advent of newer maintenance immunosuppressive medications and with very low rates of acute rejection, induction protocols for renal transplantation need to be targeted so that excessive immunosuppression and infections are avoided. Several single-center and registry data analyses in children suggest that the addition of an interleukin (IL)-2 receptor antagonist may improve graft survival compared with no induction. The safety profile of IL-2 receptor antagonists is indistinguishable from that of placebo, with no apparent difference in the incidence of infection or post-transplant lymphoproliferative disease. IL-2 receptor antagonists and polyclonal lymphocyte-depleting antibodies offer equivalent efficacy in standard-risk populations. However, in high-risk patients, acute rejection rates and graft outcomes may be improved with the use of lymphocyte-depleting agents such as Thymoglobulin. However, cytomegalovirus infection and other infections may be more common with this therapy. Therefore, in patients at high risk of graft loss, Thymoglobulin may be the preferred choice for induction therapy, while for all other patients, IL-2 receptor antagonists should be considered the first-line choice for induction therapy. Newer lymphocyte-depleting agents such as alemtuzumab may be better utilized in minimization regimens involving one or two oral maintenance immunosuppressive agents.

Alemtuzumab induction and recurrence of glomerular disease after kidney transplantation

BACKGROUND

An increase in the incidence of autoimmune diseases has been described in patients receiving alemtuzumab.

METHODS

To determine whether induction with alemtuzumab increases recurrence of glomerular disease, we performed a retrospective study in 443 patients with biopsy-proven glomerular diseases undergoing kidney transplantation. Patients receiving alemtuzumab (n=161) were compared with those receiving interleukin (IL)-2-receptor antagonists (n=217) or antithymocyte globulin (n=64).

RESULTS

Biopsy-proven glomerular disease recurrence was similar in patients induced with alemtuzumab or IL-2 receptor antagonists. Patients receiving antithymocyte antibody had a lower recurrence rate than patients treated with other induction agents, with borderline significance (hazard ratio [HR] 0.13, 95% confidence interval [95% CI] 0.02-0.98, P=0.047). Patients with systemic lupus treated with alemtuzumab had a similar re-emergence of autoreactive antibodies to patients treated with other agents. Recurrent disease increased the risk of allograft failure (HR 2.36, 95% CI 1.28-4.32, P=0.0056). The development of acute rejection and the use of deceased (vs. living) donor kidneys were also significant factors influencing graft survival. A greater risk of mortality was detected in those patients with recurrent glomerular disease (HR 3.76, 95% CI 1.37-10.35, P=0.01), whereas increased age at transplantation (HR 1.05) and the use of deceased (vs. living) donor kidneys (HR 3.20) also increased mortality. No specific induction agent significantly affected graft loss or mortality when using adjusted or unadjusted hazard ratios.

CONCLUSIONS

In this retrospective analysis, induction with alemtuzumab did not increase the rate of re-emergence of autoantibodies or biopsy-proven recurrence of glomerular disease. A slight reduction in the incidence of recurrence was observed in patients treated with thymoglobulin, yet this observation can only be validated in a prospective randomized trial.