Successful treatment of recurrent focal segmental glomerulosclerosis after kidney transplantation by plasmapheresis and rituximab

Efficacy of Rituximab in Treatment-Resistant Focal Segmental Glomerulosclerosis With Elevated Soluble Urokinase-Type Plasminogen Activator Receptor and Activation of Podocyte β3 Integrin

Introduction

Severe, nonresponsive, primary focal segmental glomerular sclerosis (FSGS) can progress to end-stage kidney disease (ESKD) in <5 years. Soluble urokinase-type plasminogen activator receptor (suPAR) may contribute to podocyte effacement by activating podocyte β3 integrin. It has been reported as a potential permeability factor and biomarker for primary FSGS. Rituximab was found to have efficacy in case reports and small series. Whether rituximab is efficacious in patients with treatment-resistant FSGS in the context of high suPAR levels and evidence of podocyte B3 integrin activation remains unknown.

Methods

In this nonblinded, open-label pilot study, the safety and efficacy of rituximab were evaluated in treatment-resistant adult patients with primary FSGS and a suPAR level > 3500 pg/ml with evidence of β3 integrin activation. Rituximab (1 g) was given on days 1 and 15. The primary outcome was proteinuria at 12 months.

Results

Only 13 of 38 screened patients qualified for the study, of whom 9 consented to participate. The baseline proteinuria and glomerular filtration rate (GFR) levels were 7.70 ± 4.61 g/d and 67 ± 38 ml/min, respectively. A transient response at 6 months was noted in 2 patients without a parallel change in suPAR level. At 12 months, there was no statistically significant improvement in proteinuria level with all participants remaining nephrotic (7.27 ± 7.30 g/d). GFR level marginally declined to 60 ± 38 ml/min with one patient progressing to ESKD. There were 2 serious infections, an infusion-related reaction and leucopenia attributed to rituximab.

Conclusion

Rituximab was ineffective when administered to adult patients with treatment-resistant primary FSGS with a high suPAR and evidence of podocyte activation.

Management of recurrent focal segmental glomerulosclerosis (FSGS) post renal transplantation

BACKGROUND

One of the common GN causing ESKD is focal segmental glomerulosclerosis (FSGS). Recurrence of FSGS post-transplantation can lead to graft loss. Data on management either prophylactically or once recurrence occurs are limited. This review article aims to assess the effective management of patients with FSGS recurrence post-transplantation, looking mainly at recurrence post prophylactic treatment and remission in case of treatment post recurrence.

METHODS

Twenty-three studies were included using the search MeSH terms "FSGS" "recurrence" "adults" "transplantation" "treatment". Search engines used were Pubmed, clinical key, Scopus and Cochrane library. Inclusion criteria were articles covered adult patients with recurrent FSGS post renal transplantation, treatment with rituximab and plasmapheresis, and articles published from 2000 tt2021. Excluded articles were paediatric population, studies with no reported outcomes of the treatment of FSGS, and Patients who received stem cell transplantation or galactose therapy.

RESULTS

Prophylactic PP did not show a reduction in recurrence of FSGS in 2/3 studies. Prophylactic rituximab was shown to reduce recurrence of FSGS in one-study and case reports. Treatment of recurrent FSGS with PP showed responses ranging from 41% to 100%. Only one study did not show improvement with PP use as treatment having a 27% remission. Treatment with rituximab showed variable results, with reports showing remission ranging from 57% to 100%. Whereas other reports showing no response at all. PP prescription reporting was variable. One study suggested intensified PP regimen while in most other studies PP was guided by the response reflected by the reduction of proteinuria.

DISCUSSION

Reviewing the treatment of recurrent FSGS is crucial, as there no consensus on treating FSGS as the disease is not very common in the adult population. The evidence of different modalities is based on small cohort studies. This paper supports the use of PP and RTX as treatment of recurrent FSGS.

CONCLUSIONS

In conclusion, PP and RTX are the main modalities to treat recurrent FSGS with varying response rates. Prophylactic PP does not play a role in preventing recurrent FSGS. Prophylactic rituximab might play a role in preventing FSGS post-transplantation. PP and RTX, when used as a treatment, show variable response rates. Larger RCTs are needed to have a strong level of evidence to base our clinical management on.

Rituximab in glomerular diseases: a case series and narrative review

INTRODUCTION

The use of Rituximab (RTX) in glomerular diseases (GD) has increased in the past years, although it is still only used in a small fraction of patients.

METHODS

A single center retrospective study of adult patients with membranous nephropathy (MN), focal segmental glomerulosclerosis (FSGS), lupus nephritis (LN), and vasculitis treated with RTX as first or second-line therapy was conducted at our center from 2010 to 2020.

RESULTS

We identified 19 patients; 36.8% had MN and 25.0% each had FSGS, LN, and vasculitis. RTX was first-line therapy in 26.3% of patients and in 73.7% it was second-line therapy. Mean follow-up time was 7.7 ± 7.2 years. In MN, 2 patients (28.6%) had complete remission (CR), 2 patients (28.6%) had partial remission (PR), and 3 patients (42.9%) had no response (NR). In FSGS, 2 patients (50.0%) presented CR, 1 patient (25.0%) had no response, and 1 patient had renal deterioration. Two patients (50.0%) had a LN class IV with a CR after RTX, 1 patient with LN class IIIC/V had no response, and 1 patient with LN class II had renal deterioration. In vasculitis, 3 patients (75.0%) presented CR and 1 patient had PR. Infusion reactions were present in 2 patients (10.5%) and one patient had multiple infectious complications.

CONCLUSIONS

The efficacy of RTX in treating different types of immune-mediated GD has been demonstrated with different response rates, but an overall safe profile. In our case series, the results are also encouraging. Longitudinal studies are needed to better understand the effect of RTX in GD.

Cyclophosphamide as a Treatment for Focal Segmental Glomerular Sclerosis Recurrence in a Kidney Transplant Patient

Patient: Female, 24-year-old

Final Diagnosis: Focal segmental glomerulosclerosis

Symptoms: Facia • lower extremity edema

Medication: —

Clinical Procedure: —

Specialty: Nephrology

Therapeutic apheresis in kidney transplantation: An updated review

Therapeutic apheresis is a cornerstone of therapy for several conditions in transplantation medicine and is available in different technical variants. In the setting of kidney transplantation, immunological barriers such as ABO blood group incompatibility and preformed donor-specific antibodies can complicate the outcome of deceased- or living- donor transplantation. Postoperatively, additional problems such as antibody-mediated rejection and a recurrence of primary focal segmental glomerulosclerosis can limit therapeutic success and decrease graft survival. Therapeutic apheresis techniques find application in these issues by separating and selectively removing exchanging or modifying pathogenic material from the patient by an extracorporeal aphaeresis system. The purpose of this review is to describe the available techniques of therapeutic aphaeresis with their specific advantages and disadvantages and examine the evidence supporting the application of therapeutic aphaeresis as an adjunctive therapeutic option to immunosuppressive agents in protocols before and after kidney transplantation.

Preoperative Low-Density Lipoprotein Apheresis for Preventing Recurrence of Focal Segmental Glomerulosclerosis after Kidney Transplantation

Background

Focal segmental glomerulosclerosis (FSGS) often develops rapidly and frequently progresses to renal failure, while the recurrence rate after kidney transplantation is 20–50%. We performed low-density lipoprotein (LDL) apheresis before kidney transplantation in FSGS patients to prevent recurrence.

Methods

Five adult patients with chronic renal failure due to FSGS undergoing living related donor kidney transplantation were investigated retrospectively. LDL apheresis was done 1-2 times before transplantation. Postoperative renal function and recurrence of FSGS were assessed.

Results

The patients were two men and three women aged 24 to 41 years. The observation period ranged from 60 days to 22 months. Preoperative LDL apheresis was performed once in one patient and twice in four patients. Blood LDL cholesterol levels were normal before LDL apheresis and remained normal both after LDL apheresis and after kidney transplantation. Additional LDL apheresis was performed once in one patient with mild proteinuria after transplantation. The renal graft survived in all patients and there was no evidence of recurrent FSGS.

Conclusions

Although the observation period was short, FSGS did not recur in all 5 patients receiving preoperative LDL apheresis. These results suggest that LDL apheresis can be effective in preventing recurrence of FSGS after kidney transplantation.

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.

High-Dose Rituximab Ineffective for Focal Segmental Glomerulosclerosis: A Long-Term Observation Study

BACKGROUND

A beneficial effect of rituximab (RTX) on focal segmental glomerulosclerosis (FSGS) in pediatric patients or in transplant recipients has been reported in isolated cases. However, the use of RTX in adult patients with idiopathic FSGS needs further investigation.

METHODS

Eight patients who had biopsy-proven FSGS (63.9 ± 14.0, range 40-81 years, 4 women, 4 men) with major risk factors precluding corticosteroids or conventional immunosuppression were treated with a high dose of RTX (8 weekly doses of 375 mg/m2) and prospectively followed up for at least 2 years (29.1 ± 8.8 months, range 24-42 months).

RESULTS

RTX failed to improve proteinuria in 7 out of 8 patients, who had persistent nephrotic proteinuria. In one case, a rapidly deteriorating renal function was also observed. Only one patient showed an improvement in renal function and a remarkable reduction in proteinuria. There were no differences in clinical or laboratory characteristics or in the CD20 B lymphocyte count after RTX between the responder and the 7 nonresponder patients.

CONCLUSIONS

Only a minority (1 of 8) in our series of adult patients with FSGS showed positive effects of high doses of RTX. Future studies are warranted to investigate more promising therapeutic options in the management of FSGS.

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.

Rituximab is not a "magic drug" in post-transplant recurrence of nephrotic syndrome

Pediatric patients with end-stage renal failure due to severe drug-resistant nephrotic syndrome are at risk of rapid recurrence after renal transplantation. Treatment options include plasmapheresis, high-dose of cyclosporine A/methylprednisolone and more recently-rituximab (anti-B CD20 monoclonal depleting antibody). We report five patients with immediate (1-2 days) post-transplant recurrence of nephrotic syndrome, treated with this kind of combined therapy including 2-4 weekly doses of 375 mg/m(2) of rituximab. Only two (of five) patients have showed full long-term remission, while the partial remission was seen in two cases, and no clinical effect at all was achieved in one patient. The correlation between B CD19 cells depletion and clinical effect was present in two cases only. Severe adverse events were present in two patients, including one fatal rituximab-related acute lung injury.

CONCLUSION

The anti-CD20 monoclonal antibody may be not effective in all pediatric cases of rapid post-transplant recurrence of nephrotic syndrome, and benefit/risk ratio must be carefully balanced on individual basis before taking the decision to use this protocol.

WHAT IS KNOWN

• nephrotic syndrome may recur immediately after renal transplantation • plasmapheresis combined with pharmacotherapy is used as rescue management • rituximab was reported as effective drug both in primary and post-transplant nephrotic syndrome What is New: • rituximab may not be effective is several cases of post-transplant nephrotic syndrome due to variety of underlying mechanisms of the disease, which may be or not be responsive to this drug • there may be no correlation between drug-induced depletion of specific B cells and clinical effect; this might suggest B-cell independent manner of rituximab action.

Recurrence of Focal and Segmental Glomerulosclerosis After Transplantation

Focal segmental glomerulosclerosis, which is a common glomerular disorder, manifests clinically with a nephrotic syndrome and has a high propensity for recurrence after kidney transplantation. The pathophysiology is currently unknown, and podocytes appear to be the target of one or several circulating factor(s) that lead to the recurrence of proteinuria after kidney transplantation. Identifying these circulating factor(s) and cells involved in its synthesis remains elusive; however, recently, our research on podocyte cytoskeleton biology has opened a new era of treatment. This review will highlight recent progress in the physiopathology of focal segmental glomerulosclerosis recurrence after transplantation and its treatment.

Recurrent focal segmental glomerulosclerosis apparently resistant to plasmapheresis improves after surgical repair of arteriovenous fistula aneurysms

Focal segmental glomerulosclerosis (FSGS) is a leading cause of end-stage renal disease and has a high recurrence rate after kidney transplantation, attributed to a circulating permeability factor. Plasmapheresis is the treatment of choice after recurrence to remove the circulating factor. We present a case of recurrent FSGS 6 years after transplantation. It is instructive because proteinuria did not respond to intensive plasmapheresis—combined with rituximab—until the possibility of ineffective apheresis secondary to multiple aneurysms in the arteriovenous fistula (AVF) was considered. Proteinuria improved soon after alternative access for plasmapheresis was secured and AVF aneurysms were surgically repaired.

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.

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.

Fatal rituximab-associated lung injury syndrome in a patient treated with rituximab for recurrence of post-transplant nephrotic syndrome

Rituximab (anti-B CD20 ab.) in recently widely used in renal transplantation.

CASE HISTORY

A 10-yr-old patient with end-stage renal failure due to multidrug-resistant NS was transplanted with renal graft from deceased donor and presented immediate recurrence of NS. PF was started on day 3 and patient received MP pulses, however with no effect. Rituximab (4 × 375 mg/m(2)) was administered. Chest radiographs taken at that time were normal. Partial remission was achieved and the patient was discharged in good condition. Sequential recurrence appeared two wk afterward. Twelve sessions of PF were performed and six pulses of MP were given, effecting a partial remission. Three months after the last dose of rituximab, patient was admitted with increasing respiratory failure, requiring mechanical ventilation. Infectious background, including CMV, BKV, mycoplasma, and pneumocystis, was not confirmed. The patient was treated with MP pulses, IVIG, and a variety of antibiotics. Ground-glass opacity was confirmed on lung CT images. Respiratory failure worsened, despite aggressive ventilation and patient passed away after three wk at ICU. A destruction of alveolar epithelium and extended pulmonary fibrosis was confirmed in the autopsy report. The case represents a fatal RALI.

Single-dose rituximab for recurrent glomerulonephritis post-renal transplant

BACKGROUND/AIMS

Post-renal transplant recurrent glomerulonephritis (GN) contributes to allograft loss. Rituximab treatment has been used in a multidose strategy with variable efficacy and toxicity. We investigated a novel single-dose approach.

METHODS

A single center, retrospective, cohort study was conducted between January 1998 and April 2012 among renal allograft recipients with recurrent GN treated with rituximab (cases) or without (controls). The primary outcome was complete response (CR, urine protein/creatinine ratio (UP/C) <0.3). Secondary outcomes included partial response (PR >50% reduction in UP/C), response relapse, treatment-response by GN type, acute rejection incidence, time to graft loss, and infection incidence.

RESULTS

The median dose of rituximab was 200 mg per patient. Of 20 rituximab cases and 13 controls, CR was achieved in eight (40%) versus four (31%), respectively (p = 0.72). Three subjects in each group achieved PR (p = 0.66). Response relapse was similar between the two groups (p = 0.47). Significantly more subjects with recurrent membranous nephropathy (MN) achieved CR with rituximab treatment (p = 0.029). Acute rejection was lower in the rituximab group versus controls (n = 0 vs. 4; p = 0.046). The mean time to graft loss was much later in the rituximab group (35 months, (95% CI 33-37)) versus controls (29 months, (95% CI 24-35)) at 36 months (p = 0.04). There was no infection increase in rituximab-treated subjects (p = 0.16).

CONCLUSION

Single-dose rituximab for treatment of recurrent GN was associated with less subsequent rejection and longer time to graft loss without increased infection, but was no more effective than regimens not using rituximab at 36-months except those with recurrent membranous GN.

Recent progress in the pathophysiology and treatment of FSGS recurrence

Focal segmental glomerulosclerosis (FSGS) is a glomerular disease characterized by proteinuria, frequent progression to end-stage renal disease, and recurrence after kidney transplantation in ∼25% of patients, which negatively impacts long-term allograft survival. Experimental studies suggest that abnormalities in T and, possibly, B cells may represent one initial pathogenic trigger, leading to podocyte injury and progressive loss. New data also support the existence of circulating permeability factors able to damage the podocytes, but no single molecule has been consistently identified as the causal pathogenic element in FSGS recurrence. Unfortunately, major progress from mechanistic studies has not translated into substantial advancements in patient treatment, with plasmapheresis (PP) and high doses of cyclosporine (CsA) remaining the mainstays of therapy. Despite consistent experimental and clinical evidence that treatment of proteinuria slows renal function decline in proteinuric nephropathies, maximal use of antiproteinuric agents such as renin angiotensin system antagonists is not routine in the management of FSGS recurrence. More recently, encouraging results have been reported with anti-CD20 depleting antibody rituximab, but further studies are needed to establish its safety/efficacy profile.

Rituximab in post-transplant pediatric recurrent focal segmental glomerulosclerosis

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pretransplantation combined therapy with plasmapheresis and rituximab in a second living-related kidney transplant pediatric recipient with a very high risk for focal segmental glomerulosclerosis recurrence

Prophylactic PP can provide some protection against post-transplantation recurrences of FSGS, but it cannot prevent recurrences in all cases. Therefore, new preventive therapies are needed. We report on a 7.9-yr-old girl treated with pretransplantation prophylactic combined therapy consisting of four sessions of PP and one dose of rituximab before a second living-related KTX. The patient had a very high risk of post-transplantation FSGS recurrence because this had occurred after the first KTX. During the 36 months since the second transplantation, she has had no evidence of proteinuria or significant infectious complications. Although our experience is too preliminary to draw any generalizable conclusions, pretransplantation combined therapy with PP and rituximab might be a possible option for the prevention of FSGS recurrence in very high-risk recipients undergoing living-donor KTXs.

Rituximab treatment for recurrence of nephrotic syndrome in a pediatric patient after renal transplantation for congenital nephrotic syndrome of Finnish type

Congenital nephrotic syndrome (CNS) of the Finnish type due to mutation in the NPHS-1 gene results in massive proteinuria due to structural abnormality in the glomerular slit diaphragm, and is usually refractory to immunosuppressive therapy. Patients eventually require bilateral nephrectomy and renal replacement therapy, with transplantation being the ultimate goal. Post-transplant recurrence of nephrotic syndrome occurs in about 25% of children and is thought to be immune-mediated secondary to antibodies formed against the nephrin protein in renal allograft. Conventional therapy with calcineurin inhibitors (CNI), cyclophosphamide and corticosteroids with or without plasmapheresis often fails to achieve remission resulting in graft loss in 12-16%. There is limited experience with use of rituximab (RTX) in pediatric organ transplant recipients. We report the first case of post-transplant recurrence of nephrotic syndrome in a 4-yr-old child with CNS due to NPHS-1 mutation in whom CNI, corticosteroid and cyclophosphamide therapy was unsuccessful, but who achieved remission after depletion of B cells with RTX, associated with a decrease in the level of anti-nephrin antibodies. The child remains in remission 5 yr following treatment. Our experience suggests that activated B cells may play a pivotal role in the recurrence of nephrosis after renal transplantation in children with CNS.

Our experience with rituximab therapy for adult-onset primary glomerulonephritis and review of literature

BACKGROUND

B cell-targeted immunosuppression with rituximab as primary treatment or when conventional therapy is contraindicated or unsuccessful can induce remission in idiopathic membranous nephropathy (IMN). We explored the efficacy and safety of rituximab therapy in an adult population with IMN and other primary glomerulonephritides.

METHOD

This study is a single-centre retrospective case review of 24 adult patients who received rituximab (RTX) for IMN (n = 11), minimal change disease (MCD, n = 7), focal segmental glomerulosclerosis (FSGS, n = 4), and membranoproliferative glomerulonephritis (MPGN, n = 2). Outcomes included the proportion of patients with complete and partial remission, frequency of relapse, the amount of post-RTX immunosuppression, and toxicity.

RESULTS

The median follow-up for all patients was 31.5 months (IQR: 15.0-44.0). Rituximab therapy induced remission in 19/24 (79.2 %) patients (IMN: 63.6 %, MCD: 100 %, FSGS: 75 %, and MPGN: 100 %). Disease recurrence in patients with ≥ 3 relapses pre-RTX therapy (MCD, n = 6 and FSGS, n = 1) decreased from 37.0 to 19.6 events per 1,000 patient-months. All patients with steroid maintenance, discontinued or achieved at least a 50 % dose reduction at 3.0 months (IQR: 1.5-8.0) post-treatment. One patient ceased CSA in addition to a 50 % steroid dose reduction 13 months post-RTX. Rituximab was well tolerated with a single serious infection (4.2 %) responsive to treatment.

CONCLUSIONS

Rituximab induced remission in IMN comparable with published reports but had an additional benefit in inducing remission in other common glomerulonephritides. Additional randomized studies are needed to confirm its potential therapeutic benefit and optimal dosing for adult-onset primary glomerulonephritis.

Case report: successful treatment of recurrent focal segmental glomerulosclerosis with a novel rituximab regimen

Focal segmental glomerulosclerosis (FSGS) is the cause of renal failure in more than 10% of pediatric patients undergoing renal transplantation. Recurrent FSGS is a major cause of pediatric allograft failure, with the risk increasing for patients undergoing retransplantation. Standard therapy for recurrent posttransplantation FSGS includes the use of intensive plasmapheresis (PP) in conjunction with cyclophosphamide or high-dose cyclosporine. However, many patients exhibit refractory disease, with rapid progression to allograft loss despite these interventions. Prior studies have reported conflicting data on the efficacy of adding rituximab therapy to the standard treatment regimen for recurrent posttransplantation FSGS. Here we present a successful therapeutic protocol with rapid elimination of PP after initiation of rituximab therapy for an adolescent patient with recurrent FSGS in the immediate postoperative period. The patient has maintained excellent allograft function through 12 months posttransplantation.

Rituximab in immunologic glomerular diseases

Experimental data suggest that the B-cell antigen CD20 may play a significant role in the pathogenesis of many diseases including glomerular diseases. These and other findings underpin the central concept of B-cell-depleting therapies that target CD20 antigen as treatments for lupus nephritis, idiopathic membranous nephropathy, focal segmental glomerulosclerosis, cryglobulinemic glomerulonephritis, antibody mediated renal allograft rejection and recurrent glomerulonephritis in renal allograft. Use of rituximab as a B-cell depleting therapy has been associated with clinical improvement and has emerged as a possible adjunct or alternative treatment option in this field of nephrology.

Therapeutic apheresis rescue mission: recurrent focal segmental glomerulosclerosis in renal allografts

Recurrent idiopathic focal segmental glomerulosclerosis (FSGS) after renal transplantation can lead to a rapid failure of the allograft. A circulating, nonimmunoglobulin factor appears to be important in the pathogenesis of this complication in many cases. Between 30% and 50% of transplant recipients with FSGS develop recurrent disease. Three major risk factors for recurrence have been identified: short duration of native kidney disease, history of recurrence with previous kidney transplant, and pediatric aged recipients. Although no properly controlled trials have been conducted, plasmapheresis has emerged as one of the important treatment modalities for this entity. Retrospective studies prior to the routine use of plasmapheresis showed graft loss rates as high as 80%, a rate much higher than that seen in more recent series managed with plasmapheresis. Duration and intensity of treatment of plasmaphersis have not been studied rigorously, but in most case series, plasmapheresis was continued until a clear diminution of proteinuria was seen. The benefit of other adjuvant therapies for this condition remains unclear, but also may play a role in the treatment of this entity.

The factors that may predict response to rituximab therapy in recurrent focal segmental glomerulosclerosis: a systematic review

Recurrence of FSGS occurs in 30–40% of allografts. Therapies for recurrence are not well established. We retrieved all published reports depicting kidney transplant recipients with focal segmental glomerulosclerosis (FSGS) recurrence, treated with rituximab, to determine factors associated with treatment response. We found 18 reports of 39 transplant recipients who received rituximab. By univariate analysis for two outcomes (no response versus any response), fewer rituximab infusions and normal serum albumin at recurrence were associated with treatment response. For 3 outcomes (no response, partial and complete remission), male gender, fewer rituximab infusions, shorter time to rituximab treatment, and normal serum albumin were associated with remission. Multivariate analysis for both models revealed that normal serum albumin at FSGS recurrence and lower age at transplant were associated with response. Rituximab for recurrence of FSGS may be beneficial for only some patients. A younger age at transplant and normal serum albumin level at recurrence diagnosis may predict response.

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.

Long-term effect of rituximab in maintaining remission of recurrent and plasmapheresis-dependent nephrotic syndrome post-renal transplantation - case report

Early recurrence of nephrotic syndrome after renal transplantation is a common serious adverse event in children with severe primary FSGS, affecting long-term outcome. There is no consensus in terms of uniform management in these cases. We describe the long-term effect of four unadjusted doses of 375 mg/m(2) i.v. rituximab, given to a five and a half-yr-old, nephrectomized child with immediate recurrence of nephrotic syndrome post-transplantation and dependency from repeated PF. Rituximab was introduced at three months post-transplantation after performing 18 sessions of PF and development of established dependency of the disease from plasma exchange. Complete remission of proteinuria was achieved with four doses, and it was maintained during next eight months of follow-up. Complete B CD(19) cell depletion was observed during four months after final dose, followed by severe depletion after eight months. No side effects of therapy were noted. Patient was free from PF, which was stopped while introducing rituximab, remaining non-proteinuric on triple immunosuppression (CsA, MMF, Pred).

A case of recurrent focal segmental glomerulosclerosis (FSGS) involving massive proteinuria (>50 g/day) immediately after renal transplantation

A 15-yr-old girl with end-stage kidney disease caused by primary focal segmental glomerulosclerosis (FSGS) underwent a living-related donor kidney transplantation. The allograft functioned well immediately after reperfusion, but massive proteinuria exceeding 50 g/d appeared on day 3. Treatment with rituximab and plasma exchange (PE) successfully decreased the proteinuria to 10 g/d. A biopsy specimen on day 30 showed no segmental glomerulosclerosis but partial interstitial infiltration of inflammatory cells. An increased number of podocytes showed intracytoplasmic vacuolization, and an electron micrograph showed diffuse mild subendothelial edema and foot process effacement. The podocytes were hypertrophied but were not detached from the basement membrane. As the therapies used to reduce the patient's proteinuria were having a limited effect, intravenous steroid pulse therapy followed by low-density lipoprotein apheresis was performed. A biopsy specimen taken on day 120 showed no segmental glomerulosclerosis. Thrombus formation in one glomerulus and packed lymphocytes in the capillary loop of another glomerulus were detected. The patient's clinical course was compatible with FSGS recurrence. Although the early pathological changes were not typical of FSGS, they might be indicative of the primary lesion that subsequently progresses to typical FSGS.

Treatment of steroid-resistant pediatric nephrotic syndrome

Children who suffer from steroid-resistant nephrotic syndrome (SRNS) require aggressive treatment to achieve remission. When intravenous high-dose methylprednisolone fails, calcineurin inhibitors, such as cyclosporine and tacrolimus, are used as the first line of treatment. A significant number of patients with SRNS progress to end-stage renal disease if remission is not achieved. For these children, renal replacement therapy can also be problematic; peritoneal dialysis may be accompanied by significant protein loss through the peritoneal membrane, and kidney allograft transplantation may be complicated by recurrence of SRNS. Plasmapheresis and rituximab were initially used for treatment of recurrent SRNS after transplantation; these are now under consideration as rescue therapies for refractory SRNS. Although the prognosis of SRNS is complicated and unfavorable, intensive treatment in the early stages of the disease may achieve remission in more than half of the patients. Therefore, timely referral of pediatric SRNS patients to pediatric nephrology specialists for histological and genetic diagnosis and treatment is highly recommended.

Combination treatment with plasmapheresis and rituximab for recurrent focal segmental glomerulosclerosis after renal transplantation

Therapy for recurrent focal segmental glomerulosclerosis (FSGS) in the renal allograft is largely based on case reports. The use of plasmapheresis alone (based on its effectiveness in children) appears less effective in adults, reaching a response rate of <40%. Recently, rituximab, an anti-CD20 monoclonal chimeric antibody, showed promising results as rescue therapy in plasmapheresis-resistant recurrent FSGS. However, following rituximab administration, response is variable, often slow and consequently overlooked. We report a series of four cases of recurrent FSGS following renal transplantation successfully treated with a combination of plasmapheresis and rituximab. Complete remission of proteinuria occurred in two and partial remission in the other two patients whereas renal function improved or remained stable. During treatment and the follow-up period (18-60 months) no severe infectious complications were observed. Our data suggest that the combination of plasmapheresis and rituximab is an acceptable treatment in patients with post-transplantation recurrent FSGS.

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.

The Factors That May Predict Response to Rituximab Therapy in Recurrent Focal Segmental Glomerulosclerosis: A Systematic Review

Recurrence of FSGS occurs in 30–40% of allografts. Therapies for recurrence are not well established. We retrieved all published reports depicting kidney transplant recipients with focal segmental glomerulosclerosis (FSGS) recurrence, treated with rituximab, to determine factors associated with treatment response. We found 18 reports of 39 transplant recipients who received rituximab. By univariate analysis for two outcomes (no response versus any response), fewer rituximab infusions and normal serum albumin at recurrence were associated with treatment response. For 3 outcomes (no response, partial and complete remission), male gender, fewer rituximab infusions, shorter time to rituximab treatment, and normal serum albumin were associated with remission. Multivariate analysis for both models revealed that normal serum albumin at FSGS recurrence and lower age at transplant were associated with response. Rituximab for recurrence of FSGS may be beneficial for only some patients. A younger age at transplant and normal serum albumin level at recurrence diagnosis may predict response.

Posttransplant recurrence of primary glomerulonephritis

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

Protocol biopsies for focal segmental glomerulosclerosis treated with plasma exchange and rituximab in a renal transplant patient

We discuss a renal transplant patient with focal segmental glomerulosclerosis (FSGS) treated with plasma exchange and rituximab. A 45-yr-old woman underwent cadaveric renal transplantation in May 2008. She had started hemodialysis support in 1991. Immediately after transplantation, massive proteinuria (1-5 g/d) appeared. Graft biopsy at one h showed minor glomerular abnormalities with partial foot process effacement on electric microscopy. Protocol biopsy at three months after transplantation for persistent proteinuria showed obvious FSGS under light microscopy. Plasma exchange and rituximab administration were subsequently initiated in August 2008, and proteinuria disappeared within a month after starting these treatments. Protocol graft biopsy one yr after transplantation (2009) showed increased global sclerosis and a decrease in segmental sclerosis. In addition, foot process effacement had recovered by one yr after transplantation. Plasma exchange and subsequent rituximab administration led to clinical remission of post-transplant FSGS with improvement in podocyte structure. Rituximab should be considered soon after several sessions of plasmapheresis in transplant patients with recurrent FSGS.

Effect of single-dose rituximab on primary glomerular diseases

BACKGROUND

A paradigm shift from such toxic 'nonspecific' therapies to selective immunomodulating regimens is necessary for glomerular diseases. Rituximab, which acts by inhibiting CD20-mediated B cell proliferation and differentiation, could be effective in the treatment of nephrotic syndrome as shown in recent reports.

DESIGN

To assess the effects of rituximab in patients with primary glomerular diseases, including minimal-change disease, immunoglobulin A (IgA) nephropathy, focal segmental glomerulonephritis, membranous nephropathy and membranoproliferative glomerulonephritis, we performed a prospective trial of the effects of single-dose rituximab therapy in 24 patients. We prospectively evaluated the serum and urinary biochemical parameters before and after 6 months of therapy.

RESULTS

In all of the patients studied, depletion of CD19 and CD20 cells was noted, with significant reduction in the degree of proteinuria from 3.7 ± 3.4 g/day at baseline to 1.3 ± 2.0 g/day at 6 months after the drug administration (p = 0.002). However, no significant changes of the serum creatinine, urinary RBC sediment, serum CD4/8 or serum IL-4 levels were observed at 6 months after the drug administration. In subjects with IgA nephropathy, while depletion of CD19 and CD20 cells was noted, no significant change in the severity of proteinuria was observed at 6 months after the drug administration as compared with the level at the baseline.

CONCLUSION

For the treatment of primary glomerular diseases, the use of a single dose of rituximab is demonstrated with no serious adverse events. Further study of the mechanism of action of rituximab in successfully treated patients could encourage new perspectives in the treatment of primary glomerular diseases.

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.

Rituximab in refractory nephrotic syndrome

The aim of this study was to establish the efficacy and safety of rituximab in refractory nephrotic syndrome (NS). Members of the International Paediatric Nephrology Association were asked to retrospectively fill in a questionnaire with details on the use of rituximab in their centres. We divided the data into three groups: group 1, patients with steroid-dependent and frequently relapsing NS; group 2, with steroid-resistant NS; group 3, with post-transplant recurrence of NS. Seventy questionnaires from 25 centres described the outcome of 28, 27 and 15 patients in groups 1, 2 and 3, respectively. Of these, 82% of patients in group 1, 44% of patients in group 2 and 60% of patients in group 3 had a good initial response. Side effects were observed in 27% of the patients, and these were mostly acute reactions. We present a large multicentre series of children with refractory NS. Children in group 1 showed the best response. The good initial response in group 3 can be biased by the accompanying treatments that were administered at the same time as rituximab. Controlled prospective trials are required to establish the value of rituximab in idiopathic NS.

Novel B cell therapeutic targets in transplantation and immune-mediated glomerular diseases

B cells and antibodies play an important role in the alloresponse to renal grafts as well as in immune-mediated glomerular diseases. In transplantation, greater recognition and improved diagnosis of antibody-mediated rejection have been a catalyst to the introduction of newer drugs and regimens that target B cells, plasma cells, and donor-specific antibodies to improve the outcome associated with antibody-mediated rejection. In immune-mediated renal disease, novel and more selective B cell therapies are gradually modifying the traditional therapeutic approach that consists of steroids and other immunosuppressants. A new era of selective and more effective immunosuppression agents that target the humoral response is finally emerging in transplantation and renal diseases.