Update on Recurrent Focal Segmental Glomerulosclerosis in Kidney Transplantation

Endothelial dysfunction in the kidney transplant population: Current evidence and management strategies

The endothelium modulates vascular homeostasis owing to a variety of vasoconstrictors and vasodilators. Endothelial dysfunction (ED), characterized by impaired vasodilation, inflammation, and thrombosis, triggers future cardiovascular (CV) diseases. Chronic kidney disease, a state of chronic inflammation caused by oxidative stress, metabolic abnormalities, infection, and uremic toxins damages the endothelium. ED is also associated with a decline in estimated glomerular filtration rate. After kidney transplantation, endothelial functions undergo immediate but partial restoration, promising graft longevity and enhanced CV health. However, the anticipated CV outcomes do not happen due to various transplant-related and unrelated risk factors for ED, culminating in poor CV health and graft survival. ED in kidney transplant recipients is an under-recognized and poorly studied entity. CV diseases are the leading cause of death among kidney transplant candidates with functioning grafts. ED contributes to the pathogenesis of many of the CV diseases. Various biomarkers and vasoreactivity tests are available to study endothelial functions. With an increasing number of transplants happening every year, and improved graft rejection rates due to the availability of effective immunosuppressants, the focus has now shifted to endothelial protection for the prevention, early recognition, and treatment of CV diseases.

Impact of Therapeutic Plasma Exchange and Rituximab for Prevention of Idiopathic Focal Segmental Glomerulosclerosis Recurrence Post-Kidney Transplantation

Background

Focal segmental glomerulosclerosis (FSGS) recurs after kidney transplantation (KT) in 30%-50% of recipients. Recurrence is associated with early graft loss in up to 60% of cases. This study aimed to assess the efficacy of therapeutic plasma exchange (TPE) combined with rituximab (RTX) in preventing early FSGS recurrence within 1 y post-KT.

Methods

This single-center, retrospective cohort study included patients receiving KT for idiopathic FSGS between June 2013 and August 2021. In May 2016, a preventative FSGS protocol was implemented where KT recipients with idiopathic FSGS received perioperative sessions of TPE followed by a dose of RTX with or without IVIG. The incidence of recurrent FSGS within the first year posttransplantation was assessed between the FSGS protocol cohort versus the historical group of patients who did not undergo prophylactic treatment.

Results

A total of 65 patients received KT for idiopathic FSGS during the study period. Forty patients were included in the FSGS protocol cohort and 25 in the control cohort. When assessing clinical recurrence with proteinuria, there were significantly fewer cases in the FSGS protocol cohort versus the control cohort, 1 versus 5 patients (3% versus 20%, P = 0.03). There were no instances of death-censored graft loss at 1 y in the protocol cohort versus 2 cases in the control cohort (0% versus 8%, P = 0.14).

Conclusions

TPE combined with RTX may prevent early FSGS recurrence without significant rates of infection.

Pathogenesis of Focal Segmental Glomerulosclerosis and Related Disorders

Focal segmental glomerulosclerosis (FSGS) is the morphologic manifestation of a spectrum of kidney diseases that primarily impact podocytes, cells that create the filtration barrier of the glomerulus. As its name implies, only parts of the kidney and glomeruli are affected, and only a portion of the affected glomerulus may be sclerosed. Although the diagnosis is based primarily on microscopic features, patient stratification relies on clinical data such as proteinuria and etiological criteria. FSGS affects both children and adults and has an elevated risk of progression to end-stage renal disease. The prevalence of FSGS is rising among various populations, and the efficacy of various therapies is limited. Therefore, understanding the pathophysiology of FSGS and developing targeted therapies to address the complex needs of FSGS patients are topics of great interest that are currently being studied across various clinical trials. We discuss the etiology of FSGS, describe the major contributing pathophysiological pathways, and outline emerging therapeutic strategies along with their pitfalls.

Precision medicine for focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is one of the common causes of nephrotic syndrome in adults and children worldwide. FSGS consists of a group of kidney diseases classified based on specific histopathological features. The current classification of FSGS makes it difficult to distinguish individual differences in pathogenesis, disease progression, and response to treatment. In recent years, the spread of next-generation sequencing, updates in biological techniques, and improvements of treatment have changed our understanding of FSGS. In this review, we will discuss the use of genetic testing in patients with FSGS, explore its clinical significance from a genetic identification perspective, and introduce several new biomarkers, that may help in the early diagnosis of FSGS and guide the development of specific or targeted therapies, so as to understand the biological characteristics in FSGS. This will certainly help develop more effective and safer treatments and advance precision medicine.

Efficacy and Safety of Bleselumab in Preventing the Recurrence of Primary Focal Segmental Glomerulosclerosis in Kidney Transplant Recipients: A Phase 2a, Randomized, Multicenter Study

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage kidney disease and frequently recurs after kidney transplantation. Recurrent FSGS (rFSGS) is associated with poor allograft and patient outcomes. Bleselumab, a fully human immunoglobulin G4 anti-CD40 antagonistic monoclonal antibody, disrupts CD40-related processes in FSGS, potentially preventing rFSGS.

METHODS

A phase 2a, randomized, multicenter, open-label study of adult recipients (aged ≥18 y) of a living or deceased donor kidney transplant with a history of biopsy-proven primary FSGS. The study assessed the efficacy of bleselumab combined with tacrolimus and corticosteroids as maintenance immunosuppression in the prevention of rFSGS >12 mo posttransplantation, versus standard of care (SOC) comprising tacrolimus, mycophenolate mofetil, and corticosteroids. All patients received basiliximab induction. The primary endpoint was rFSGS, defined as proteinuria (protein-creatinine ratio ≥3.0 g/g) with death, graft loss, or loss to follow-up imputed as rFSGS, through 3 mo posttransplant.

RESULTS

Sixty-three patients were followed for 12 mo posttransplantation. Relative decrease in rFSGS occurrence through 3 mo with bleselumab versus SOC was 40.7% (95% confidence interval, -89.8 to 26.8; P = 0.37; absolute decrease 12.7% [95% confidence interval, -34.5 to 9.0]). Central-blinded biopsy review found relative (absolute) decreases in rFSGS of 10.9% (3.9%), 17.0% (6.2%), and 20.5% (7.5%) at 3, 6, and 12 mo posttransplant, respectively; these differences were not statistically significant. Adverse events were similar for both treatments. No deaths occurred during the study.

CONCLUSIONS

In at-risk kidney transplant recipients, bleselumab numerically reduced proteinuria occurrence versus SOC, but no notable difference in occurrence of biopsy-proven rFSGS was observed.

Anuria after kidney transplantation diagnosed as early recurrence of focal segmental glomerulosclerosis combined with acute calcineurin inhibitor nephrotoxicity: a case report and literature review

BACKGROUND

Primary focal segmental glomerulosclerosis (FSGS) is a glomerular disease that sometimes recurs in patients after kidney transplantation (KT) and increases the risk of graft loss. Proteinuria is a common early sign of recurrent FSGS, but an abrupt decrease in urine volume is rare. Herein, we report a patient with early recurrence of FSGS with anuria following KT.

CASE PRESENTATION

A 55-year-old man with end-stage kidney disease caused by primary FSGS experienced anuria on postoperative day 2 following deceased donor KT. Laboratory results revealed that serum tacrolimus trough levels were consistently elevated at the time of anuria. At first, we considered acute calcineurin inhibitor (CNI) nephrotoxicity based on graft biopsy on light microscopy, laboratory findings, and clinical courses. However, the allograft function did not recover even after discontinuation of CNI, and recurrent FSGS was diagnosed 2 weeks later on electron microscopy. A total of 13 sessions of plasmapheresis and two administrations of rituximab (375 mg/m2) were required to treat recurrent FSGS. The patient achieved a partial response, and the spot urine protein-to-creatinine ratio decreased from 15.5 g/g creatinine to 5.2 g/g creatinine. At 5 months following KT, the serum creatinine level was stable at 1.15 mg/dL.

CONCLUSIONS

These findings highlight that anuria can occur in cases of early recurrence of FSGS combined with acute CNI nephrotoxicity.

Steroid-Resistant Nephrotic Syndrome due to NPHS2 Variants Is Not Associated With Posttransplant Recurrence

INTRODUCTION

Unlike idiopathic nephrotic syndrome (NS), hereditary podocytopathies are not expected to recur after kidney transplantation. However, some reports of posttransplant recurrence of NS in patients carrying variants in the NPHS2 gene have been described, notably with the p.Arg138Gln variant, which is more prevalent in Europe. The objective of this study was to assess the risk of recurrence after kidney transplantation in a large cohort of patients with biallelic NPHS2 pathogenic variants.

METHODS

Since January 2010, 61 patients identified at Necker-Enfants Malades Hospital and 56 enrolled in the PodoNet Registry with biallelic variants in the NPHS2 gene were transplanted and were compared with 44 transplanted children with steroid-resistant NS (SRNS) without any identified pathogenic variant.

RESULTS

Of the 117 patients, 23 carried the p.Arg138Gln variant in the homozygous state and 16 in the compound heterozygous state. The other 78 patients carried different variants in the homozygous (n = 44) or compound heterozygous state. Only 1 patient with NPHS2-related SRNS experienced posttransplant recurrence (median follow-up of cohort 8.5 years [2.5-15]). Conversely, 7 of 44 patients (16%) without any identified pathogenic variant recurred within a maximum of 7 days after transplantation (median follow-up 8.9 years [0.6-13.9]).

CONCLUSION

In this large cohort, the risk of patients with causative variants in the NPHS2 gene to develop NS recurrence after kidney transplantation was extremely low. This is coherent with the pathophysiology of intrinsic slit-diaphragm disease. These data are reassuring and should be considered when counselling patients, making living kidney donation, whether related or not, a safe choice.

Clinicopathological differences in focal segmental glomerulosclerosis depending on the accompanying pathophysiological conditions in renal allografts

Primary focal segmental glomerulosclerosis (FSGS) is thought to be caused by circulating factors leading to podocytopathy, whereas segmental sclerotic lesions (FSGS lesions) have several causes. We studied the clinicopathological differences of FSGS-lesions in 258 cases of FSGS in renal allografts, depending on the following accompanying pathophysiology: recurrence of primary FSGS, calcineurin inhibitor (CNI)-induced arteriolopathy, antibody-mediated rejection (ABMR), and other conditions. All cases were categorized with the Columbia classification. Recurrent FSGS developed the earliest after transplantation and showed the highest percentage of the collapsing (COL) variant in which collapse of the glomerular capillaries with epithelial hypertrophy was apparent. FSGS accompanying CNI-induced arteriolopathy predominantly developed the not otherwise specified (NOS) variant, showing severe ultrastructural endothelial injury. On the contrary, approximately 7% of the cases showed the COL variant, presenting glomerular endothelial damage such as double contours of glomerular basement membrane and endothelial cell swelling as well as epithelial cell proliferation. FSGS with ABMR had the highest creatinine levels and cellular variant percentage, with marked inflammation and ultrastructural endothelial injury. Approximately two-thirds of the cases without ABMR, CNI-induced arteriopathy, or recurrent FSGS had other coexisting conditions such as glomerulonephritis, T cell-mediated rejection, and reflux nephropathy with progressive tubulointerstitial fibrosis. Most of these cases were of the NOS variant. The clinicopathologic features of post-transplant FSGS differed depending on the associated conditions, and endothelial injury was apparent especially in cases of CNI-induced arteriolopathy and ABMR. Precise observation of FSGS lesions may facilitate the diagnosis and clinical management of FSGS during renal transplantation.

A Policy Call to Address Rare Kidney Disease in Health Care Plans

Despite a large number of people globally being affected by rare kidney diseases, research support and health care policy programs usually focus on the management of the broad spectrum of CKD without particular attention to rare causes that would require a targeted approach for proper cure. Hence, specific curative approaches for rare kidney diseases are scarce, and these diseases are not treated optimally, with implications on the patients' health and quality of life, on the cost for the health care system, and society. There is therefore a need for rare kidney diseases and their mechanisms to receive the appropriate scientific, political, and policy attention to develop specific corrective approaches. A wide range of policies are required to address the various challenges that target care for rare kidney diseases, including the need to increase awareness, improve and accelerate diagnosis, support and implement therapeutic advances, and inform the management of the diseases. In this article, we provide specific policy recommendations to address the challenges hindering the provision of targeted care for rare kidney diseases, focusing on awareness and prioritization, diagnosis, management, and therapeutic innovation. In combination, the recommendations provide a holistic approach aiming for all aspects of rare kidney disease care to improve health outcomes, reduce the economic effect, and deliver benefits to society. Greater commitment from all the key stakeholders is now needed, and a central role should be assigned to patients with rare kidney disease to partner in the design and implementation of potential solutions.

Over expression of ubiquitin-conjugating enzyme E2O in bone marrow mesenchymal stromal cells partially attenuates acute myeloid leukaemia progression

Bone marrow mesenchymal stromal cells (BM-MSCs) are implicated in the pathogenesis of acute myeloid leukaemia (AML). However, due to the high heterogeneity of AML the mechanism underlying the cross-talk between MSCs and leukaemia cells is not well understood. We found that mixed-lineage leukaemia-AF9 (MLL-AF9)-induced AML mice-derived MSCs had higher proliferative viability compared to wild-type mice-derived MSCs with ubiquitin-conjugating enzyme E2O (Ube2o) down-regulation. After overexpression of UBE2O in AML-derived MSCs, the growth capacity of MSCs was reduced with nuclear factor kappa B subunit 1 (NF-κB) pathway deactivation. In vitro co-culture assay revealed that UBE2O-overexpression MSCs suppressed the proliferation and promoted apoptosis of AML cells by direct contact. In vivo results revealed that the leukaemia burden was reduced and the overall survival of AML mice was prolonged, with decreased dissemination of leukaemia cells in BM, spleen, liver and peripheral blood. Additionally, subcutaneous tumorigenesis revealed that tumour growth was also suppressed in the UBE2O-overexpression MSCs group. In conclusion, UBE2O was expressed at a low level in MLL-AF9-induced AML mice-derived MSCs. Overexpression of UBE2O in MSCs suppressed their proliferation through NF-κB pathway deactivation, which resulted in AML suppression. Our study provides a theoretical basis for a BM microenvironment-based therapeutic strategy to control disease progression.

Primary Focal Segmental Glomerulosclerosis Plasmas Increase Lipid Droplet Formation and Perilipin-2 Expression in Human Podocytes

Many patients with primary focal segmental glomerulosclerosis (FSGS) develop recurrence of proteinuria after kidney transplantation. Several circulating permeability factors (CPFs) responsible for recurrence have been suggested, but were never validated. We aimed to find proteins involved in the mechanism of action of CPF(s) and/or potential biomarkers for the presence of CPF(s). Cultured human podocytes were exposed to plasma from patients with FSGS with presumed CPF(s) or healthy and disease controls. Podocyte proteomes were analyzed by LC-MS. Results were validated using flow cytometry, RT-PCR, and immunofluorescence. Podocyte granularity was examined using flow cytometry, electron microscopy imaging, and BODIPY staining. Perilipin-2 protein expression was increased in podocytes exposed to presumed CPF-containing plasmas, and correlated with the capacity of plasma to induce podocyte granularity, identified as lipid droplet accumulation. Elevated podocyte perilipin-2 was confirmed at protein and mRNA level and was also detected in glomeruli of FSGS patients whose active disease plasmas induced podocyte perilipin-2 and lipid droplets. Our study demonstrates that presumably, CPF-containing plasmas from FSGS patients induce podocyte lipid droplet accumulation and perilipin-2 expression, identifying perilipin-2 as a potential biomarker. Future research should address the mechanism underlying CPF-induced alterations in podocyte lipid metabolism, which ultimately may result in novel leads for treatment.

Incorporation of Genetic Studies in the Kidney Transplant Evaluation Clinic: The Value of a Multidisciplinary Approach

BACKGROUND

Recent studies identified underlying genetic causes in a proportion of patients with various forms of kidney disease. In particular, genetic testing reclassified some focal segmental glomerulosclerosis (FSGS) cases into collagen type 4 (COL4)-related nephropathy. This knowledge has major implications for counseling prospective transplant recipients about recurrence risk and screening biologically related donors. We describe our experience incorporating genetic testing in our kidney transplant multidisciplinary practice.

METHODS

Patients' DNA was analyzed using whole exome sequencing for a comprehensive kidney gene panel encompassing 344 genes associated with kidney diseases and candidate genes highly expressed in the kidney. Results were correlated with phenotype by a multidisciplinary committee of nephrologists, renal pathologists, geneticists, and genetic counselors. Between October 2018 and July 2020, 30 recipient and 5 donor candidates completed testing.

RESULTS

Among recipient candidates, 24 (80%) carried the diagnosis of FSGS, 2 (6.7%) tubulointerstitial nephritis, and 1 (3.3%) nephrolithiasis, and 3 (10%) had an unknown cause of kidney disease. The yield for pathogenic/likely pathogenic variants was 43.3%, with majority being COL4 variants (53.8%). Among those with FSGS diagnosis, the yield was 10 of 24 (41.6%), with 29% reclassified into a COL4-related nephropathy. Family history of kidney disease was the only clinical characteristic difference between recipients with positive and negative results (76.9 versus 29.4%; P = 0.025). One of 5 donors tested positive for a pathogenic/likely pathogenic variant and was excluded from donation.

CONCLUSIONS

We conclude that thoughtful use of genetic testing can be valuable for kidney donor selection and transplant recipient management.

Integrated genomic, transcriptomic and metabolomic analysis reveals MDH2 mutation-induced metabolic disorder in recurrent focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) has an over 30% risk of recurrence after kidney transplantation (Ktx) and is associated with an extremely high risk of graft loss. However, mechanisms remain largely unclear. Thus, this study identifies novel genes related to the recurrence of FSGS (rFSGS). Whole genome-wide sequencing and next-generation RNA sequencing were used to identify the candidate mutant genes associated with rFSGS in peripheral blood mononuclear cells (PBMCs) from patients with biopsy-confirmed rFSGS after KTx. To confirm the functional role of the identified gene with the MDH2 c.26C >T mutation, a homozygous MDH2 c.26C >T mutation in HMy2.CIR cell line was induced by CRISPR/Cas9 and co-cultured with podocytes, mesangial cells, or HK2 cells, respectively, to detect the potential pathogenicity of the c.26C >T variant in MDH2. A total of 32 nonsynonymous single nucleotide polymorphisms (SNPs) and 610 differentially expressed genes (DEGs) related to rFSGS were identified. DEGs are mainly enriched in the immune and metabolomic-related pathways. A variant in MDH2, c.26C >T, was found in all patients with rFSGS, which was also accompanied by lower levels of mRNA expression in PBMCs from relapsed patients compared with patients with remission after KTx. Functionally, co-cultures of HMy2.CIR cells overexpressing the mutant MDH2 significantly inhibited the expression of synaptopodin, podocin, and F-actin by podocytes compared with those co-cultured with WT HMy2.CIR cells or podocytes alone. We identified that MDH2 is a novel rFSGS susceptibility gene in patients with recurrence of FSGS after KTx. Mutation of the MDH2 c.26C >T variant may contribute to progressive podocyte injury in rFSGS patients.

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.

Human pluripotent stem cell-derived kidney organoids for personalized congenital and idiopathic nephrotic syndrome modeling

Nephrotic syndrome (NS) is characterized by severe proteinuria as a consequence of kidney glomerular injury due to podocyte damage. In vitro models mimicking in vivo podocyte characteristics are a prerequisite to resolve NS pathogenesis. The detailed characterization of organoid podocytes resulting from a hybrid culture protocol showed a podocyte population that resembles adult podocytes and was superior compared with 2D counterparts, based on single-cell RNA sequencing, super-resolution imaging and electron microscopy. In this study, these next-generation podocytes in kidney organoids enabled personalized idiopathic nephrotic syndrome modeling, as shown by activated slit diaphragm signaling and podocyte injury following protamine sulfate, puromycin aminonucleoside treatment and exposure to NS plasma containing pathogenic permeability factors. Organoids cultured from cells of a patient with heterozygous NPHS2 mutations showed poor NPHS2 expression and aberrant NPHS1 localization, which was reversible after genetic correction. Repaired organoids displayed increased VEGFA pathway activity and transcription factor activity known to be essential for podocyte physiology, as shown by RNA sequencing. This study shows that organoids are the preferred model of choice to study idiopathic and congenital podocytopathies.

Summary: Kidney organoid podocytes generated from human pluripotent stem cells using a hybrid differentiation protocol allow podocyte pathophysiology modeling that leads to congenital as well as idiopathic nephrotic syndrome in patients.

Prevention of Triglyceridemia by (Non-)Anticoagulant Heparin(oids) Does Not Preclude Transplant Vasculopathy and Glomerulosclerosis

Background: In renal transplantation, chronic transplant dysfunction (CTD) is associated with increased PCSK9 and dyslipidemia. PCSK9 is an enzyme that increases plasma cholesterol levels by downregulating LDLR expression. We recently showed increased PCSK9-syndecan-1 interaction in conditions of proteinuria and renal function loss. Treatment with heparin(oids) might be a therapeutic option to improve dyslipidemia and CTD. We investigated the effects of (non-)anticoagulant heparin(oids) on serum lipids, syndecan-1 and PCSK9 levels, and CTD development. Methods: Kidney allotransplantation was performed from female Dark Agouti to male Wistar Furth recipients. Transplanted rats received daily subcutaneous injections of saline, unfractionated heparin, and RO-heparin or NAc-heparin (2 mg heparin(oid)/kg BW) until sacrifice after 9 weeks of treatment. Results: Saline-treated recipients developed hypertension, proteinuria, and loss of creatinine clearance (all p < 0.05 compared to baseline), along with glomerulosclerosis and arterial neo-intima formation. Saline-treated recipients showed significant increase in plasma triglycerides (p < 0.05), borderline increase in non-HDLc/HDLc (p = 0.051), and ∼10-fold increase in serum syndecan-1 (p < 0.05), without significant increase in serum PCSK9 at 8 weeks compared to baseline. Heparin and non-anticoagulant RO-heparin administration in transplanted rats completely prevented an increase in triglycerides compared to saline-treated recipients at 8 weeks (both p < 0.05). Heparin(oids) treatment did not influence serum total cholesterol (TC), plasma syndecan-1 and PCSK9 levels, creatinine clearance, proteinuria, glomerulosclerosis, and arterial neo-intima formation, 8 weeks after transplantation. Combining all groups, increased syndecan-1 shedding was associated with TC (r = 0.5; p = 0.03) and glomerulosclerosis (r = 0.53; p = 0.021), whereas the non-HDLc/HDLc ratio was associated with the neo-intimal score in the transplanted kidneys (r = 0.65; p < 0.001). Conclusion: Prevention of triglyceridemia by (non-)anticoagulant heparin(oids) neither influenced PCSK9/syndecan-1 nor precluded CTD, which however did associate with the shedding of lipoprotein clearance receptor syndecan-1 and the unfavorable cholesterol profile.

Recurrent glomerulonephritis after kidney transplantation: a practical approach

PURPOSE OF REVIEW

This review will provide a practical approach in the assessment of kidney failure patients with primary glomerulonephritides (GN) being considered for kidney transplantation, focusing on high-risk subtypes of immunoglobulin A nephropathy, focal segmental glomerulosclerosis, idiopathic membranous glomerulonephritis and membranoproliferative glomerulonephritis.

RECENT FINDINGS

Recurrent glomerulonephritis remains one of the most common causes of allograft loss in kidney transplant recipients. Although the epidemiology and clinical outcomes of glomerulonephritis recurrence occurring after kidney transplantation are relatively well-described, the natural course and optimal treatment strategies of recurrent disease in kidney allografts remain poorly defined. With a greater understanding of the pathophysiology and treatment responses of patients with glomerulonephritis affecting the native kidneys, these discoveries have laid the framework for the potential to improve the management of patients with high-risk glomerulonephritis subtypes being considered for kidney transplantation.

SUMMARY

Advances in the understanding of the underlying immunopathogenesis of primary GN has the potential to offer novel therapeutic options for kidney patients who develop recurrent disease after kidney transplantation. To test the efficacy of novel treatment options in adequately powered clinical trials requires a more detailed understanding of the clinical and histological characteristics of kidney transplant recipients with recurrent glomerulonephritis.