Immunoadsorbtion and rituximab therapy in a second living-related kidney transplant patient with recurrent focal segmental glomerulosclerosis

Therapeutic apheresis in kidney diseases: an updated review

Besides conventional medical therapies, therapeutic apheresis has become an important adjunctive or alternative therapeutic option to immunosuppressive agents for primary or secondary kidney diseases and kidney transplantation. The available therapeutic apheresis techniques used in kidney diseases, including plasma exchange, double-filtration plasmapheresis, immunoadsorption, and low-density lipoprotein apheresis. Plasma exchange is still the leading extracorporeal therapy. Recently, growing evidence supports the potential benefits of double-filtration plasmapheresis and immunoadsorption for more specific and effective clearance of pathogenic antibodies with fewer side effects. However, more randomized controlled trials are still needed. Low-density lipoprotein apheresis is also an important supplementary therapy used in patients with recurrent focal segmental glomerulosclerosis. This review collects the latest evidence from recent studies, focuses on the specific advantages and disadvantages of these techniques, and compares the discrepancy among them to determine the optimal therapeutic regimens for certain kidney diseases.

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.

IPNA clinical practice recommendations for the diagnosis and management of children with steroid-resistant nephrotic syndrome

Idiopathic nephrotic syndrome newly affects 1-3 per 100,000 children per year. Approximately 85% of cases show complete remission of proteinuria following glucocorticoid treatment. Patients who do not achieve complete remission within 4-6 weeks of glucocorticoid treatment have steroid-resistant nephrotic syndrome (SRNS). In 10-30% of steroid-resistant patients, mutations in podocyte-associated genes can be detected, whereas an undefined circulating factor of immune origin is assumed in the remaining ones. Diagnosis and management of SRNS is a great challenge due to its heterogeneous etiology, frequent lack of remission by further immunosuppressive treatment, and severe complications including the development of end-stage kidney disease and recurrence after renal transplantation. A team of experts including pediatric nephrologists and renal geneticists from the International Pediatric Nephrology Association (IPNA), a renal pathologist, and an adult nephrologist have now developed comprehensive clinical practice recommendations on the diagnosis and management of SRNS in children. The team performed a systematic literature review on 9 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, formulated recommendations and formally graded them at a consensus meeting, with input from patient representatives and a dietician acting as external advisors and a voting panel of pediatric nephrologists. Research recommendations are also given.

Immunoadsorption in nephrotic syndrome: Where are we now and where are we going from here?

Idiopathic nephrotic syndrome (INS) is characterized by three different entities, namely minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS) and membranous nephropathy (MN). While there is an increasing understanding of primary MN with the discovery of antibodies directed against phospholipase A2 receptor (PLA2R Ab) and thrombospondin type 1 domain-containing 7A, circulatory factors causative of inducing MCD and FSGS remain in part elusive. Extracorporeal treatment forms (mostly plasma exchange) have been reserved for patients with either a disease course refractory to commonly prescribed immunosuppressive drugs or to patients with recurrence after kidney transplantation. There is a paucity of data supporting the use of immunoadsorption (IAS) in the management of MCD and MN and evidence to perform LDL-apheresis in the former is limited to reports from Japan. Treatment with IAS in primary FSGS has shown mixed responses, possibly biased by including treatment-resistant cases in the absence of genetic testing. In those with recurrence of the disease following kidney transplantation, IAS has shown high remission rates with an acceptable safety profile. There is a need to compare IAS to plasma exchange (PLEX) in this indication and due to a higher amount of plasma processed during one session, IAS may have advantages over PLEX. Removal of PLA2R Ab by IAS is currently being tested in a phase II clinical trial. More clinical trials in a prospective and randomized fashion need to be designed to prove the concept that IAS may be a treatment option for INS. While PLEX is still the leading extracorporeal treatment form in these indications, this review aims to highlight the efficacy and safety of IAS in the management of INS.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Multiple Targets for Novel Therapy of FSGS Associated with Circulating Permeability Factor

A plasma component is responsible for altered glomerular permeability in patients with focal segmental glomerulosclerosis. Evidence includes recurrence after renal transplantation, remission after plasmapheresis, proteinuria in infants of affected mothers, transfer of proteinuria to experimental animals, and impaired glomerular permeability after exposure to patient plasma. Therapy may include decreasing synthesis of the injurious agent, removing or blocking its interaction with cells, or blocking signaling or enhancing cell defenses to restore the permeability barrier and prevent progression. Agents that may prevent the synthesis of the permeability factor include cytotoxic agents or aggressive chemotherapy. Extracorporeal therapies include plasmapheresis, immunoadsorption with protein A or anti-immunoglobulin, or lipopheresis. Oral or intravenous galactose also decreases P_alb activity. Studies of glomeruli have shown that several strategies prevent the action of FSGS sera. These include blocking receptor-ligand interactions, modulating cell reactions using indomethacin or eicosanoids 20-HETE or 8,9-EET, and enhancing cytoskeleton and protein interactions using calcineurin inhibitors, glucocorticoids, or rituximab. We have identified cardiotrophin-like cytokine factor 1 (CLCF-1) as a candidate for the permeability factor. Therapies specific to CLCF-1 include potential use of cytokine receptor-like factor (CRLF-1) and inhibition of Janus kinase 2. Combined therapy using multiple modalities offers therapy to reverse proteinuria and prevent scarring.

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.

Recurrence and Treatment after Renal Transplantation in Children with FSGS

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

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.

Individualized scheme of immunoadsorption for the recurrence of idiopathic focal segmental glomerulosclerosis in the graft: a single center experience

OBJECTIVES

To explore the role of immunoadsorption (IA) for the treatment of idiopathic focal segmental glomerulosclerosis (FSGS) recurrence in the renal allograft, if applied in a personalized manner.

METHODS

We studied patients with end-stage renal disease (ESRD) due to idiopathic FSGS, transplanted between 2001 and 2010. Patients with FSGS recurrence were treated with daily sessions of IA for the first week, followed by an every other day scheme and then individualized tapering until discontinuation. Complete remission was defined as a reduction of 24-h proteinuria to ≤ 0.5 g/day and partial remission as a reduction of 24-h proteinuria to 50% or more from baseline.

RESULTS

Of the 18 renal transplant recipients with ESRD due to idiopathic FSGS, 12 (66.7%) experienced disease recurrence in a mean time of 0.75 months post-transplantation (KTx), with a mean proteinuria of 8.9 g/day at the time of recurrence. The mean recipient age was 30.8 years; the mean donor age was 47.4 years, while living related donors provided the allograft in seven cases. Four of the patients received therapy with rituximab in addition to IA. During a mean time of follow-up of 48.3 months, seven patients (58.3%) achieved complete remission, and five (41.7%) partial remission. At the end of follow-up, eight patients (66.7%) had functioning grafts, being in sustained remission, in contrast to four patients (33.3%), who ended up in ESRD because of FSGS recurrence.

CONCLUSIONS

IA was shown efficacious in a small series of patients with recurrent FSGS in the graft. Renal function remained stable in eight of the 12 patients with FSGS recurrence.

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.

Successful treatment of recurrent focal segmental glomerulosclerosis with a low dose rituximab in a kidney transplant recipient

Recurrence of focal segmental glomerulosclerosis (FSGS) is a major therapeutic challenge in kidney transplantation (KT). Although intensive plasmapheresis and high-dose rituximab have been introduced to treat recurrent FSGS, the most effective dosage and regimen of rituximab have not been determined. Herein we reported the first case of successful treatment of recurrent FSGS with a low-dose rituximab. The patient showed marked proteinuria (3.5 g/d) and oliguria 2 d after KT. Two courses of plasmapheresis and immunoglobulin were applied to the patient, however, nephrotic range proteinuria persisted and creatinine level increased to 3.56 mg/dL. Five months post-transplant, the patient received injection with only one dose of rituximab 100 mg, without further plasmapheresis, which resulted in immediate reduction of serum creatinine and full remission of proteinuria during the following 18 months. This case suggested that recurrent FSGS, which frequently relapses after plasmapheresis, could be treated successfully with a low-dose rituximab even without plasmapheresis.

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.

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.

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.

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).

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.

Simultaneous clinical resolution of focal segmental glomerulosclerosis associated with chronic lymphocytic leukaemia treated with fludarabine, cyclophosphamide and rituximab

Background

Although renal involvement in advanced haematological malignancies is common, glomerulonephritis associated with lymphoproliferative disorders is rare, and the related pathogenetic mechanisms are still poorly understood. We present a rare case of chronic lymphocytic leukaemia(CLL)-associated focal segmental glomerulosclerosis with nephrotic-range proteinuria.

Case presentation

A 53-year-old Caucasian man, previously healthy, with no history of hypertension, alcohol use or smoking presented with rapid weight gain, massive peripheral oedema, and hypertension. Laboratory findings included a white blood cell count of 49,800 cells/mm³ with an absolute lymphocyte count of 47,000 cells/mm³, serum albumin of 2.3 g/dL, urea 65 mg/dL, and creatinine 1.5 mg/dL. A 24-hour urine collection contained 7.1 g protein and significant haematuria. A peripheral blood smear showed mature lymphocytosis and smudge cells. Diagnostic imaging showed mild paraaortic lymphadenopathy with no renal abnormalities. Bone marrow aspiration and trephine biopsy showed diffuse and focal infiltration with B-CLL lymphocytes. Percutaneous renal biopsy revealed total sclerosis in 3/21(14%) of the glomeruli and focal and segmental solidification and sclerosis in 4/21 (19%) glomeruli. A regimen of fludarabine, cyclophosphamide and rituximab was successful in inducing remission of the CLL and clinical resolution of the nephritic-range proteinuria.

Conclusions

A multidisciplinary approach to monitor both the malignancy and the glomerular lesions is crucial for the optimal management of paraneoplastic glomerulonephritis. Although chemotherapy with fludarabine, cyclophosphamide and rituximab successfully treated CLL-associated nephrotic syndrome in our patient, further studies are required to confirm efficacy in this setting.

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.

Rituximab and chronic plasmapheresis therapy of nephrotic syndrome in renal transplantation patients with recurrent focal segmental glomerulosclerosis

Focal segmental golmerulosclerosis (FSGS) recurs in 30% of patients with FSGS who received a first renal transplant and in more than 80% of patients receiving a second transplant after a recurrence. Plasmapheresis (PP) can reduce proteinuria and even induce complete remission of proteinuria. We studied the effects of rituximab therapy associated with chronic PP treatment of nephrotic syndrome among 3 adult renal transplant recipients with recurrent FSGS after a fourth, a second, or a third transplantation, respectively. All of these subjects had displayed recurrences in previous transplants. The 3 patients were treated with PP once a week after recurrence; the first and second patients were treated with PP before transplantation surgery seeking to prevent FSGS recurrence. The patients' follow-up times were 21, 35, and 33 months, respectively, before rituximab therapy. During that time, the patients were treated with 133, 62, and 94 PP sessions, respectively. All of the patients received rituximab (375 mg/m(2)/wk, 4 doses) and 1 PP session before each rituximab dose. We confirmed the effectiveness of rituximab therapy by demonstrating peripheral CD19 cells to be undetectable after therapy. None of the patients treated with rituximab achieved remission of proteinuria. One patient showed proteinuria reduced by 26%, the second by 44%, and the third had no change. None of the patients had infectious complications or graft loss at 1 month follow-up. Our experience with 3 adult renal transplant recipients with recurrent FSGS and chronic PP therapy showed failure of rituximab to achieve remission in nephrotic syndrome.

Role of altered insulin signaling pathways in the pathogenesis of podocyte malfunction and microalbuminuria

PURPOSE OF REVIEW

In diabetic nephropathy, insulin resistance and hyperinsulinemia correlate with the development of albuminuria. The possibility that altered insulin signaling in glomerular cells and particularly podocytes contributes to the development of diabetic nephropathy will be discussed.

RECENT FINDINGS

Whereas normal podocytes take up glucose in response to insulin, diabetic podocytes become insulin resistant in experimental diabetic nephropathy prior to the development of significant albuminuria. Both clinical and experimental data suggest that insulin sensitizers may be renoprotective independent of their systemic effects on the metabolic control of diabetes.

SUMMARY

We will review the clinical and experimental evidence that altered insulin signaling correlates with the development of diabetic nephropathy in both type 1 and type 2 diabetes, and that insulin sensitizers may be superior to other hypoglycemic agents in the prevention of diabetic nephropathy. We will then review potential mechanisms by which altered podocyte insulin signaling may contribute to the development of diabetic nephropathy. Understanding the role of podocytes in glucose metabolism is important because it may lead to the discovery of novel pathogenetic mechanisms of diabetic nephropathy, it may affect current strategies for prevention and treatment of diabetic nephropathy, and it may allow the identification of novel therapeutic targets.

Use of rituximab in focal glomerulosclerosis relapses after renal transplantation

BACKGROUND

Focal and segmental glomerulosclerosis (FSGS) accounts for more than 10% of all cases of renal diseases leading to renal failure in children. After renal transplantation, 20% to 40% of FSGS relapse, frequently leading to renal loss.Plasmapheresis is considered the first option to treat relapses by several authors but is often ineffective. The anti-CD20 monoclonal antibody rituximab has been proposed as a possible treatment.

METHODS

We reviewed the effect of rituximab in seven children or young adults with pretransplant FSGS and relapse of proteinuria after transplantation who did not respond to intensive plasmapheresis.

RESULTS

After treatment, urine protein disappeared in three patients, was reduced by 70% in one patient and by 50% in one patient. No response was observed in one patient who had a quick deterioration of renal function and reached end-stage renal failure after 3 months. One additional patient developed a severe reaction a few minutes after the start of the first rituximab infusion.

CONCLUSION

Rituximab is a possible option to treat some resistant cases of FSGS with relapsing proteinuria after transplantation. It is important that therapy is started early after evidence of failure of plasmapheresis, before sclerosis develops in the glomeruli. The response to treatment can occur after several months. During the follow-up period, CD19 cells should be monitored carefully, and additional rituximab infusions considered to maintain B-cell depletion.

Monoclonal antibodies for podocytopathies: rationale and clinical responses

The podocytopathies, including minimal-change nephropathy, focal segmental glomerulosclerosis, collapsing glomerulopathy, and diffuse mesangial sclerosis, involve diverse types of injury to podocytes. These injuries can have genetic causes, or can be caused by viral infection, mechanical stress, medication or-probably-immunologic injury. Several lines of evidence-including the immunosuppressive effects of standard therapies-suggest a role for immunologic injury in some cases, but the precise pathologic mechanisms are far from clear. Despite this uncertainty, newly available biologic therapies that target immune cells and cytokines have been used to treat a number of patients with different podocytopathies. Of these therapies, the greatest experience has been gained with rituximab. The data on all such therapies remain too fragmentary to provide firm conclusions, but further clinical research with such agents might help to define pathogenetic pathways and could potentially contribute to new therapies.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

New insights into the pathophysiology of idiopathic nephrotic syndrome

Corticoresistant idiopathic nephrotic syndrome (INS) is a glomerulopathy of unknown etiology whose original aspect is its recurrence after kidney transplantation in 30 to 50% of patients with end-stage renal disease. This suggests the involvement of circulating factors that would alter the glomerular filtration barrier, but whose nature remains elusive. Although a T cell immune origin has been suggested, the actual role of these cells in INS recurrence is still unclear. Here we present an 8-year-old patient with corticoresistant INS who developed a recurrence of her initial disease after kidney transplantation. Rituximab therapy was proposed 11 months after transplantation; although no immediate effect was induced, a slow but persistent decrease in proteinuria began a few months after Rituximab infusions despite cessation of plasma exchanges and steroid therapy. The pathophysiology of INS and the putative mechanisms of action of Rituximab are discussed.

Rituximab for post-transplant recurrences of FSGS

A 14-yr-old boy whose primary kidney disease was FSGS developed severe recurrence of proteinuria immediately after a second living-related kidney transplant. Despite pre- and post-operative PP and immunosuppressive treatment consisting of steroids, CycA, daclizumab, and MMF, daily protein excretion and serum creatinine increased. We therefore administered rituximab on the fourth day of transplantation. He received four weekly doses of rituximab (375 mg/m(2)/dose), which resulted in a rapid clearing of circulating CD19-positive B cells, and remission of proteinuria was achieved six wk after the first rituximab treatment. Graft function was excellent six months after transplantation with proteinuria of 8 mg/m(2)/h. We conclude that rituximab may be an effective treatment for post-transplant recurrence of FSGS.

Rituximab treatment for severe steroid- or cyclosporine-dependent nephrotic syndrome: a multicentric series of 22 cases

Several case reports suggest that rituximab (RTX) could be effective in steroid-dependent nephrotic syndrome, but RTX efficacy has not yet been studied in a series of patients. Safety and efficacy of RTX were assessed in a multicenter series of 22 patients aged 6.3-22 years with severe steroid-dependent nephrotic syndrome or steroid-resistant but cyclosporin-sensitive idiopathic nephrotic syndrome. Patients were treated with two to four infusions of RTX. Seven patients were nephrotic at the time of RTX treatment. Peripheral B cells were depleted in all subjects. Remission was induced in three of the seven proteinuric patients. One or more immunosuppressive (IS) treatments could be withdrawn in 19 patients (85%), with no relapse of proteinuria and without increasing other IS drugs. RTX was effective in all patients when administered during a proteinuria-free period in association with other IS agents. When relapses occurred, they were always associated with an increase in CD19 cell count. Adverse effects were observed in 45% of cases, but most of them were mild and transient. This study suggests that RTX could be an effective treatment for severe steroid-dependent nephrotic syndrome.