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

A randomized controlled trial of preemptive rituximab to prevent recurrent focal segmental glomerulosclerosis post-kidney transplant (PRI-VENT FSGS): protocol and study design

Background

Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage kidney disease requiring kidney transplantation and can recur in the allograft in 30-80% of recipients resulting in reduced graft survival. Plasmapheresis has shown efficacy in treating some cases of recurrent FSGS but isolated plasmapheresis has not demonstrated efficacy in preventing recurrent FSGS. Rituximab has had anecdotal success in preventing recurrence in a single center study but has not been studied in combination with plasmapheresis for preventing FSGS recurrence.

Methods

We are conducting a randomized, controlled, multicenter clinical trial of adult and pediatric kidney transplant recipients with primary FSGS to assess whether plasmapheresis in combination with rituximab prevents recurrent disease post-transplantation.

Discussion

Rituximab combined with plasmapheresis is a promising, novel therapy to prevent recurrent FSGS, a disease with limited therapeutic options and no consensus guidelines for prevention or treatment.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT03763643, identifier NCT03763643.

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.

Role of therapeutic apheresis in the treatment of pediatric kidney diseases

Therapeutic apheresis utilizes apheresis procedures in the treatment of a variety of conditions including kidney disease. Therapeutic plasma exchange (TPE) is the most common modality employed with the rationale of rapid reduction of a pathogenic substance distributed primarily in the intravascular compartment; however other techniques which adsorb such pathogenic substances or alter the immune profile have been utilized in diseases affecting native and transplanted kidneys. This article discusses the modalities and technical details of therapeutic apheresis and summarizes its role in individual diseases affecting the kidney. Complications related to pediatric apheresis procedures and specifically related to apheresis in kidney disease are also discussed. Though therapeutic apheresis modalities are employed frequently in children with kidney disease, most experiences are extrapolated from adult studies. International and national registries need to be established to elucidate the role of apheresis modalities in children with kidney disease.

Kidney Transplantation for Focal Segmental Glomerulosclerosis: Can We Prevent Its Recurrence? Personal Experience and Literature Review

Background: Primary focal segmental glomerulosclerosis (FSGS) is associated with a high risk of recurrence after kidney transplantation with a major risk of graft loss despite preventive or curative treatments. Aim: to assess graft survival in FSGS kidney-transplant recipients and to compare those that had a relapse with those that had no relapse. Patients/Methods: we included 17 FSGS kidney-transplant recipients between January 2000 and January 2020, separated retrospectively into two groups (recurrences: n = 8 patients; no recurrences: n = 9 patients). FSGS recurrence was defined as having proteinuria of ≥3 g/g or urinary creatinine of ≥3 g/day. All patients received an induction therapy; maintenance immunosuppressive therapy at post-transplantation relied on tacrolimus/mycophenolate mofetil/steroids. In order to prevent or treat FSGS recurrence, patients received apheresis sessions plus rituximab. Results: FSGS recurrence rate was 47%. All patients that relapsed with a first graft also relapsed with subsequent grafts. Median time to recurrence was 3 (min: 1; max: 4745) days, despite rituximab/apheresis prophylaxis. Mean age was significantly lower in the relapsers (group 1) than in the non-relapsers (group 2); i.e., 47 ± 11 vs. 58 ± 9 years (p = 0.04). Time to progression to stage 5 chronic kidney disease (CKD) and young age at FSGS diagnosis were lower in group 1 compared to group 2; i.e., 5 (min: 1; max: 26) vs. 2 (min: 1; max: 26) years, and 16 (min: 4; max: 55) vs. 34 (min: 6; max 48) years, respectively. There was no difference between the two groups in terms of progression to CKD stage 5 on the native kidneys, averaging 7 years in both groups (p = 0.99). In group 1, seven patients received rituximab/apheresis prophylaxis, although this did not prevent the recurrence of FSGS. Conclusion: pretransplant prophylaxis with plasmapheresis/rituximab did not appear to reduce the risk of recurrence of primary FSGS on the graft, but could allow remission in the event of recurrence.

Recurrent Glomerular Disease after Kidney Transplantation: Diagnostic and Management Dilemmas

Recurrent glomerular disease after kidney transplant remains an important cause of allograft failure. Many of the different entities post-transplant still suffer from incomplete knowledge on pathophysiology, and therefore lack targeted and effective therapies. In this review, we focus on specific clinical dilemmas encountered by physicians in managing recurrent glomerular disease by highlighting new insights into the understanding and treatment of post-transplant focal segmental glomerulosclerosis, membranous nephropathy, atypical hemolytic uremic syndrome, C3 glomerulopathy, amyloid light-chain (AL) amyloidosis, and IgA nephropathy.

Lupus podocytopathy superimposed on diabetic glomerulosclerosis: A case report

RATIONALE

Lupus podocytopathy (LP) is an entity that is increasingly being reported in the literature on systemic lupus erythematosus (SLE). LP is characterized by nephrotic syndrome in SLE patients with diffuse glomerular podocyte foot process effacement and no immune complex deposits along the capillary loops. Histologically, LP typically mimics minimal change disease or primary focal segmental glomerulosclerosis (FSGS) on a background of ISN/RPS class I or II lupus nephritis. In situations where there are coexistent glomerular diseases, however, LP may be easily masked by background lesions and overlapping clinical symptoms.

PATIENT CONCERNS

We report the case of a 24-year-old woman with type I diabetes, hypertension, psoriasis/rash, and intermittent arthritis who presented with abrupt onset of severe nephrotic proteinuria and renal insufficiency. Renal biopsy revealed nodular glomerulosclerosis and FSGS. Immune deposits were not identified by immunofluorescence or electron microscopy. Ultrastructurally, there was diffuse glomerular basement membrane thickening and over 90% podocyte foot process effacement. With no prior established diagnosis of SLE, the patient was initially diagnosed with diabetic nephropathy with coexistent FSGS, and the patient was started on angiotensin-converting enzyme inhibitors (ACEI) and diuretics. However, nephrotic proteinuria persisted and renal function deteriorated. The patient concurrently developed hemolytic anemia with pancytopenia.

DIAGNOSES

Subsequent to the biopsy, serologic results showed positive autoantibodies against double strand DNA (dsDNA), Smith antigen, ribonucleoprotein (RNP), and Histone. A renal biopsy was repeated, revealing essentially similar findings to those of the previous biopsy. Integrating serology and clinical presentation, SLE was favored. The pathology findings were re-evaluated and considered to be most consistent with LP and coexistent diabetic nephropathy, with superimposed FSGS either as a component of LP or as a lesion secondary to diabetes or hypertension.

INTERVENTIONS

The patient was started on high-dose prednisone at 60 mg/day, with subsequent addition of mycophenolate mofetil and ACEI, while prednisone was gradually tapered.

OUTCOMES

The patient's proteinuria, serum creatinine, complete blood counts, skin rash, and arthritis were all significantly improved.

CONCLUSION

The diagnosis of LP when confounded by other glomerular diseases that may cause nephrotic syndrome can be challenging. Sufficient awareness of this condition is necessary for the appropriate diagnosis and treatment.

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.

Rituximab or plasmapheresis for prevention of recurrent focal segmental glomerulosclerosis after kidney transplantation: A systematic review and meta-analysis

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) is one of the most common glomerular diseases leading to renal failure. FSGS has a high risk of recurrence after kidney transplantation. Prevention of recurrent FSGS using rituximab and/or plasmapheresis has been evaluated in multiple small studies with conflicting results.

AIM

To assess the risk of recurrence of FSGS after transplantation using prophylactic rituximab with or without plasmapheresis, and plasmapheresis alone compared to the standard treatment group without preventive therapy.

METHODS

This meta-analysis and systematic review were performed by first conducting a literature search of the MEDLINE, EMBASE, and Cochrane databases, from inception through March 2021; search terms included ‘FSGS,’ ’steroid-resistant nephrotic syndrome’, ‘rituximab,’ and ‘plasmapheresis,’. We identified studies that assessed the risk of post-transplant FSGS after use of rituximab with or without plasmapheresis, or plasmapheresis alone. Inclusion criteria were: Original, published, randomized controlled trials or cohort studies (either prospective or retrospective), case–control, or cross-sectional studies; inclusion of odds ratio, relative risk, and standardized incidence ratio with 95% confidence intervals (CI), or sufficient raw data to calculate these ratios; and subjects without interventions (controls) being used as comparators in cohort and cross-sectional studies. Effect estimates from individual studies were extracted and combined using a random effects model.

RESULTS

Eleven studies, with a total of 399 kidney transplant recipients with FSGS, evaluated the use of rituximab with or without plasmapheresis; thirteen studies, with a total of 571 kidney transplant recipients with FSGS, evaluated plasmapheresis alone. Post-transplant FSGS recurred relatively early. There was no significant difference in recurrence between the group that received rituximab (with or without plasmapheresis) and the standard treatment group, with a pooled risk ratio of 0.82 (95%CI: 0.47-1.45, I² = 65%). Similarly, plasmapheresis alone was not associated with any significant difference in FSGS recurrence when compared with no plasmapheresis; the pooled risk ratio was 0.85 (95%CI: 0.60-1.21, I² = 23%). Subgroup analyses in the pediatric and adult groups did not yield a significant difference in recurrence risk. We also reviewed and analyzed post-transplant outcomes including timing of recurrence and graft survival.

CONCLUSION

Overall, the use of rituximab with or without plasmapheresis, or plasmapheresis alone, is not associated with a lower risk of FSGS recurrence after kidney transplantation. Future studies are required to assess the effectiveness of rituximab with or without plasmapheresis among specific patient subgroups with high-risk for FSGS recurrence.

Recurrent Focal Segmental Glomerulosclerosis After Kidney Transplantation in African Americans: Review of the Current Evidence

OBJECTIVES

In many countries of sub-Saharan Africa, the most common causes of end-stage kidney disease are hypertension, chronic glomerulonephritis, and diabetes mellitus. So far, literature on recurrent focal segmental glomerulosclerosis in sub-Saharan African populations is limited. With the intention of providing guidance for best practices in sub-Saharan Africa, we reviewed available evidence for African Americans, a population with a similar genetic background. We chose this population as a pseudo-population to show how similar genetic backgrounds can predict disease occurrence in similar populations residing in different continents.

MATERIALS AND METHODS

Our extended PubMed and Scopus literature search used these key words: "focal segmental glomerulosclerosis in African Americans" (search 1), "recurrent focal segmental glomerulosclerosis after kidney transplantation" (search 2), "risk factors for recurrent focal segmental glomerulosclerosis" (search 3); and "APOL1 gene and kidney transplantation" (search 4).

RESULTS/CONCLUSIONS

Search 1 yielded 4 articles, search 2 yielded 44 articles, search 3 yielded 6 articles, and search 4 yielded 8 articles. African Americans were shown to be disproportionately predisposed to endstage kidney disease, traceable to focal segmental glomerulosclerosis (the most common cause of glomerulonephritis leading to end-stage kidney disease). Apolipoprotein L1 presence in 22% of African Americans explained the odds ratio of 17 in developing focal segmental glomerulosclerosis and 8 times lifetime risk of end-stage kidney disease. Focal segmental glomerulosclerosis recurred in 30% of kidney transplant recipients; risk factors included young age, rapid progression to end-stage kidney disease, and White race recipient. Circulating permeability factors played a central role in primary and recurrent focal segmental glomerulosclerosis. For recurrent cases, transplant biopsy has remained the gold standard for diagnosis, with treatment involving a multi-modal approach, often resulting in partial or complete remission of proteinuria; allograft loss can occur if treatment is not successful. More randomized clinical trials are needed to chart the way forward for prolonged allograft function.

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.

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.

Pre-emptive rituximab and plasma exchange does not prevent disease recurrence following living donor renal transplantation in high-risk idiopathic SRNS

BACKGROUND

Children with non-genetic steroid-resistant nephrotic syndrome (SRNS) are at high risk of disease recurrence (DR) and graft loss following renal transplant (RT). Although pre-emptive plasma exchange (PE) and rituximab have been suggested to prevent DR, there is insufficient published data to support this practice. The aim is to study the role of pre-emptive PE and rituximab in the prevention of DR in children with non-genetic SRNS undergoing living donor (LD) RT.

METHODS

Prospective single-centre study of four consecutive children (age 6-17 years) with non-genetic SRNS (including two with previous graft loss due to DR) who underwent LD RT between July 2014 and September 2016. All patients received a single dose of rituximab 375 mg/m² 2-4 weeks prior to the RT and four sessions of PE in the week prior to RT. All patients had previously undergone bilateral native nephrectomies.

RESULTS

All children had early DR (2-26 days) following LD RT. Following early initiation of PE, three children achieved partial remission (PR) or complete remission (CR) 5-22 days after commencing treatment. One child continued to have heavy proteinuria along with graft dysfunction despite 52 sessions of PE and lost the graft 5 months after RT. At the latest follow-up of 36-60 months following RT, one child remains in CR and two are in PR. The latest eGFR was 45-104 ml/min/1.73m².

CONCLUSIONS

Pre-emptive rituximab and PE does not prevent DR in high-risk non-genetic SRNS. Prompt initiation of PE following DR appears to achieve PR or CR in the majority of patients.

Recurrent and de novo Glomerulonephritis After Kidney Transplantation

The prevalence, pathogenesis, predictors, and natural course of patients with recurrent glomerulonephritis (GN) occurring after kidney transplantation remains incompletely understood, including whether there are differences in the outcomes and advances in the treatment options of specific GN subtypes, including those with de novo GN. Consequently, the treatment options and approaches to recurrent disease are largely extrapolated from the general population, with responses to these treatments in those with recurrent or de novo GN post-transplantation poorly described. Given a greater understanding of the pathogenesis of GN and the development of novel treatment options, it is conceivable that these advances will result in an improved structure in the future management of patients with recurrent or de novo GN. This review focuses on the incidence, genetics, characteristics, clinical course, and risk of allograft failure of patients with recurrent or de novo GN after kidney transplantation, ascertaining potential disparities between “high risk” disease subtypes of IgA nephropathy, idiopathic membranous glomerulonephritis, focal segmental glomerulosclerosis, and membranoproliferative glomerulonephritis. We will examine in detail the management of patients with high risk GN, including the pre-transplant assessment, post-transplant monitoring, and the available treatment options for disease recurrence. Given the relative paucity of data of patients with recurrent and de novo GN after kidney transplantation, a global effort in collecting comprehensive in-depth data of patients with recurrent and de novo GN as well as novel trial design to test the efficacy of specific treatment strategy in large scale multicenter randomized controlled trials are essential to address the knowledge deficiency in this disease.

Rituximab and Therapeutic Plasma Exchange in Recurrent Focal Segmental Glomerulosclerosis Postkidney Transplantation

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage renal disease with a high rate of recurrence after kidney transplantation. Several factors, such as white race, rapid progression, and previous allograft failure due to recurrence, were found to be risks of recurrence. Data are limited on the benefits of rituximab and/or therapeutic plasma exchange (TPE) in preventing recurrence. In this study, we sought to assess the efficacy of rituximab and TPE for the prevention and treatment of recurrent FSGS after kidney transplantation.

METHODS

We enrolled 66 patients with FSGS in this prospective observational study and followed their outcomes. Patients with high risk for recurrence received preventative therapy with TPE and/or rituximab.

RESULTS

Twenty-three (62%) of the 37 patients who received preventative therapy developed recurrence compared with 14 (51%) recurrences of the 27 patients who did not receive any therapy (P = 0.21). There was a trend for less relapse when rituximab was used as a therapy for recurrent FSGS (6/22 vs 9/18, P = 0.066). We used a clinical score of 5 values to assess the prediction of FSGS recurrence. A score of 3 or more had a predictive receiver operating characteristic curve of 0.72. Treatment with TPE and/or rituximab resulted in better allograft survival than historical studies. Allograft failure because of recurrent FSGS occurred in only 6 (9%) patients.

CONCLUSIONS

Preventative therapies do not decrease the recurrence rate of recurrent FSGS. However, prompt treatment of recurrence with these therapies may result in improved outcomes.

Treatment of recurrent focal segmental glomerulosclerosis post-kidney transplantation in Australian and New Zealand children: A retrospective cohort study

Disease recurrence affects around a third of renal transplants for children with FSGS and is associated with poor graft outcomes. Unfortunately, there are no large trials guiding treatment for recurrent FSGS. We aimed to describe current therapies and treatment response for recurrent FSGS in 4 centres in Australia and New Zealand. Data were collected on children (age <18 years) with recurrent FSGS (1990-2015). We reviewed patient charts to obtain clinical information. Ethics approval was obtained from the relevant boards. Complete records were available on 24 patients (62% female, 54% Caucasian). Median time to first recurrence was 4 days (IQR 2-5 days). There were 14 separate treatment regimens, involving an average of 2 agents. The most common therapies were plasma exchange (20/24 patients, 83%), cyclosporin (15/24, 63%), and methylprednisolone (9/24, 38%). Full remission was achieved in 15 (63%), partial remission in 2 (8%), and no remission in 7 (29%) patients. Of the patients with no remission, 5 lost their graft to recurrent disease and 1 to concurrent acute vascular rejection. The plethora of different treatment regimens reflects the poor evidence guiding management for recurrent FSGS. More research is needed to improve outcomes.

Therapeutic Plasma Exchange in Pediatric Renal Transplantation Experience of One Decade and 389 Sessions

OBJECTIVE

There are no specific recommendations for therapeutic plasma exchange (TPE) in children after renal transplantation. The purpose of this study was to report the experience with TPE in a pediatric transplant setting.

MATERIALS AND METHODS

59 patients (mean age 12.5 ± 4.5 years) undergoing renal transplantation. Indications for TPE included the recurrence of nephrotic syndrome (NS; n = 30) and atypical hemolytic uremic syndrome (n = 6), chronic antibody-mediated rejection (cAMR; n = 20), sensitization (n = 2), and immune thrombocytopenia (n = 1). The single-filtration TPE was performed in all cases. In 74.7% of patients, fresh frozen plasma was used as a replacement fluid. In 25.3% of patients, 4% albumin solution was used as a replacement fluid. Criteria for TPE efficacy included a decrease of proteinuria and normalization of renal function in NS; a normalization of platelet count, C3, and hemoglobin concentration in aHUS; improvement in renal function; and reduction of donor-specific antibodies in cAMR; and removal of antiplatelet antibodies in immune thrombocytopenia.

RESULTS

Efficacy results for patients with NS: 59.3% achieved remission, 25.9% achieved partial remission, and 14.8% achieved no remission, respectively. For patients with atypical hemolytic uremic syndrome there was remission in 66.6% and no remission in 33.4%. For patients with cAMR there was remission in 75% and no remission in 25%. Antiplatelet antibodies disappeared after TPE in 1 patient. In 9% of TPE procedures, minor complications were noted. All patients were on posttransplant maintenance immunosuppression and several children received additional treatment (intravenous immunoglobulin therapy or rituximab) during TPE therapy.

CONCLUSION

TPE therapy (combined with immunosuppression) was an effective tool in most pediatric cases after renal transplantation with low incidence of minor adverse events.

The effect of peri-transplant plasmapheresis in the prevention of recurrent FSGS

Many pediatric centers utilize a variety of protocols including preemptive plasmapheresis to prevent the recurrence of FSGS post-transplant. But the effectiveness of this expensive, time-consuming process of plasmapheresis in the prevention of FSGS recurrence is still unclear. We retrospectively reviewed all pediatric cases of FSGS in our center that received a kidney transplant and compared the transplant and patient outcomes of those transplanted after 2006 who received pretransplant plasmapheresis to those prior to 2006 who did not. Of the 57 children with FSGS, 31 and 26 were transplanted before and after 2006, respectively. The cohorts differed significantly in keeping with the center immunosuppression protocol changes, and prior to 2006, the recipients were significantly younger. All children with FSGS transplanted after 2006 underwent three and one sessions of 1.0 plasma volume/exchange plasmapheresis with fresh frozen plasma replacement prior to the transplant in living and deceased donors, respectively, in addition to five sessions of every other day post-transplant pheresis. The incidence (27% vs 26%, P = 1.0) and time to recurrence of FSGS in the kidney allograft (P = .22) were not significantly different in patients that did and did not undergo prophylactic plasmapheresis. We need to re-evaluate the role of preemptive plasmapheresis in the prevention of FSGS recurrence in a prospective multicenter study.

Whole Exome Sequencing of Patients with Steroid-Resistant Nephrotic Syndrome

BACKGROUND AND OBJECTIVES

Steroid-resistant nephrotic syndrome overwhelmingly progresses to ESRD. More than 30 monogenic genes have been identified to cause steroid-resistant nephrotic syndrome. We previously detected causative mutations using targeted panel sequencing in 30% of patients with steroid-resistant nephrotic syndrome. Panel sequencing has a number of limitations when compared with whole exome sequencing. We employed whole exome sequencing to detect monogenic causes of steroid-resistant nephrotic syndrome in an international cohort of 300 families.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Three hundred thirty-five individuals with steroid-resistant nephrotic syndrome from 300 families were recruited from April of 1998 to June of 2016. Age of onset was restricted to <25 years of age. Exome data were evaluated for 33 known monogenic steroid-resistant nephrotic syndrome genes.

RESULTS

In 74 of 300 families (25%), we identified a causative mutation in one of 20 genes known to cause steroid-resistant nephrotic syndrome. In 11 families (3.7%), we detected a mutation in a gene that causes a phenocopy of steroid-resistant nephrotic syndrome. This is consistent with our previously published identification of mutations using a panel approach. We detected a causative mutation in a known steroid-resistant nephrotic syndrome gene in 38% of consanguineous families and in 13% of nonconsanguineous families, and 48% of children with congenital nephrotic syndrome. A total of 68 different mutations were detected in 20 of 33 steroid-resistant nephrotic syndrome genes. Fifteen of these mutations were novel. NPHS1, PLCE1, NPHS2, and SMARCAL1 were the most common genes in which we detected a mutation. In another 28% of families, we detected mutations in one or more candidate genes for steroid-resistant nephrotic syndrome.

CONCLUSIONS

Whole exome sequencing is a sensitive approach toward diagnosis of monogenic causes of steroid-resistant nephrotic syndrome. A molecular genetic diagnosis of steroid-resistant nephrotic syndrome may have important consequences for the management of treatment and kidney transplantation in steroid-resistant nephrotic syndrome.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

Kidney retransplantation in children following rejection and recurrent disease

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

Treatment of Focal Segmental Glomerulosclerosis Recurrence in the Renal Allograft: A Report of Two Cases

Focal segmental glomerulosclerosis (FSGS) causes glomerular lesions that can progress to end-stage renal disease. It is suspected to be caused by a circulating factor that is amenable to plasmapheresis removal and exhibits a risk for recurrence in the renal allograft. We present two patients with FSGS recurrence in their allograft kidneys diagnosed by biopsy after significant proteinuria developed in the posttransplant setting. Treatment with therapeutic plasma exchange induced long-term remission in both patients. Spot urine protein:creatinine ratios were monitored and treatment was continued until a target of <0.5 was achieved. In patient number two, a second peak in proteinuria and azotemia was ultimately attributable to ureteral stenosis and these values normalized following repair. In conclusion, therapeutic plasma exchange is an effective treatment for FSGS recurring following renal transplant.

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.

Primary disease recurrence—effects on paediatric renal transplantation outcomes

Primary disease recurrence after renal transplantation is mainly diagnosed by examination of biopsy samples, but can also be associated with clinical symptoms. In some patients, recurrence can lead to graft loss (7-8% of all graft losses). Primary disease recurrence is generally associated with a high risk of graft loss in patients with focal segmental glomerulosclerosis, membranous proliferative glomerulonephritis, primary hyperoxaluria or atypical haemolytic uraemic syndrome. By contrast, disease recurrence is associated with a limited risk of graft loss in patients with IgA nephropathy, renal involvement associated with Henoch-Schönlein purpura, antineutrophil cytoplasmic antibody-associated glomerulonephritis or lupus nephritis. The presence of systemic diseases that affect the kidneys, such as sickle cell anaemia and diabetes mellitus, also increases the risk of delayed graft loss. This Review provides an overview of the epidemiology, pathophysiology and management of primary disease recurrence in paediatric renal graft recipients, and describes the overall effect on graft survival of each of the primary diseases listed above. With appropriate management, few paediatric patients should be excluded from renal transplantation programmes because of an increased risk of recurrence.

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.

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.

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.

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.

Therapeutic apheresis for renal disorders

This review summarizes the clinical evidence and practical details for the use of plasmapheresis and other apheresis modalities for each indication in nephrology. Updated information on the molecular biology and immunology of each renal disease is discussed in relation to the rationale for apheresis therapy and its place amid other available treatments. Autoantibody-mediated diseases, such as anti-GBM (anti-glomerular basement membrane) glomerulonephritis (GN), ANCA (antineutrophil cytoplasmic antibody)-related GN and the antibody-mediated type of TTP (thrombotic thrombocytopenic purpura), and alloantibody-mediated diseases such as kidney transplant sensitization and humoral rejection, can be treated by various plasmapheresis methods. These include standard plasmapheresis with a replacement volume, or plasmapheresis with online plasma purification using adsorption columns or secondary filtration. However, it should be noted that the pathogenic molecules implicated in FSGS (focal segmental glomerulosclerosis), myeloma cast nephropathy, and perhaps other diseases are too small to be removed by most online purification methods. A great majority of controlled trials and series on which evidence-based treatment recommendations are made were performed using centrifugal plasmapheresis; it is presumed that membrane-separation plasmapheresis is equally efficacious. For some rarer diseases, such as MPGN (membranoproliferative GN) type 2 with factor H abnormalities or C3Nef (C3 nephritic factor) autoantibodies, there are only a few case reports, but enough scientific understanding to warrant a trial of plasmapheresis in severe cases. Photopheresis, which is effective for cell-mediated rejection in heart and lung transplantation, has not yet found a place in the routine treatment of kidney transplant rejection.

Plasmapheresis in immunologic renal disease

Plasmapheresis has been used in the management of immunologic renal disease for the last 40 years. The rationale behind this approach is to remove pathogenic immune mediators, such as autoantibodies and immune complexes, from the circulation. There may also be benefit in depleting proinflammatory molecules, such as complement components and coagulation factors. Initial experience was gained in Goodpasture's disease, in which antiglomerular basement membrane antibodies were known to be pathogenic. More recently, a role for autoantibodies has become clear in small-vessel systemic vasculitis and some cases of hemolytic uremic syndrome/thrombotic thrombocytopenic purpura. Removal of immune complexes is thought to be important in cryoglobulinemia and systemic lupus erythematosus. Plasmapheresis is used in renal transplantation for the treatment of acute antibody-mediated rejection, and for desensitization of patients with preformed anti-HLA antibodies or those receiving an ABO-incompatible transplant. Although many of the early studies were uncontrolled, there has been an increasing number of randomized controlled trials in recent years. The aim of this article is to summarize current indications for the use of plasmapheresis in immunologic renal disease.