Rituximab and low-dose cyclosporine combination therapy for steroid-resistant focal segmental glomerulosclerosis

Efficacy of rituximab and risk factors for poor prognosis in patients with childhood-onset steroid-resistant nephrotic syndrome: a multicenter study

BACKGROUND

The efficacy of rituximab in steroid-resistant nephrotic syndrome (SRNS) is controversial. We previously reported that rituximab in combination with methylprednisolone pulse therapy (MPT) and immunosuppressants was associated with favorable outcomes. We determined risk factors for poor response following rituximab treatment, which remains unknown.

METHODS

This retrospective study included 45 patients with childhood-onset SRNS treated with rituximab across four pediatric kidney facilities. Treatment effects were categorized as complete remission (CR), partial remission (PR), and no remission (NR) at one year after rituximab treatment. The primary outcome was the rate of CR, PR, and NR. Risk factors for non-CR were calculated with multivariate logistic regression. Adverse events and the relationship between disease status at one year and long-term prognosis were also evaluated.

RESULTS

The rates of CR, PR, and NR at one year were 69%, 24%, and 7%, respectively. The median time from rituximab administration to CR was 90 days. The median follow-up period after rituximab administration was 7.4 years. In multivariate analysis, significant risk factors for poor response were the pathologic finding of focal segmental glomerular sclerosis and a long interval between SRNS diagnosis and rituximab administration. The rates of CR were 90.3% and 21.4% in patients receiving rituximab within and after 6 months following SRNS diagnosis, respectively (p < 0.001). Five patients developed chronic kidney disease stage G5, including 2 of the 11 patients with PR and all 3 patients with NR, whereas none of the 31 patients with CR developed chronic kidney disease stage G5.

CONCLUSION

Early administration of rituximab in combination with MPT and immunosuppressants might achieve favorable outcomes in patients with SRNS.

Rituximab treatment of adults with primary focal segmental glomerulosclerosis

To evaluate the efficacy and safety of rituximab (RTX) in the treatment of primary focal segmental glomerulosclerosis (FSGS) in adults. The clinical data of patients with primary FSGS who received RTX treatment in the First Affiliated Hospital of Zhengzhou University were analyzed retrospectively. The selected patients received RTX twice or four times, with a single dose of 375 mg/m², and the interval between two times of administration of RTX was 2-4 weeks. The treatment target is to achieve the clearance of B cells (peripheral blood B cell count < 5/μl). The primary outcome measures were remission and recurrence of renal disease, and the secondary outcome measures were adverse events and renal outcomes. A total of 14 FSGS patients were included, including 12 males, 9 with glucocorticoid-dependent or frequently relapsing nephrotic syndrome, and 3 with newly diagnosed nephrotic syndrome. After RTX treatment, 7 patients with glucocorticoid-dependent/recurrent nephrotic syndrome were completely relieved. At 6 months of follow-up, glucocorticoids were discontinued in all patients except 1 patient. The other 5 patients achieved partial remission (PR), of which 1 patient relapsed after PR, and 1 initial patient achieved complete remission. One patient progressed to end-stage renal disease (ESRD) after 4 months of follow-up. RTX in the treatment of adult glucocorticoid-dependent/relapsing FSGS can reduce the risk of recurrence and help to decline or discontinue the use of glucocorticoid and immunosuppressants.

B cell phenotype, activity, and function in idiopathic nephrotic syndrome

Idiopathic nephrotic syndrome (INS) is the most frequent glomerular disease in childhood. However, its underlying etiology mechanism lacks thorough understanding. Previous studies have described INS as a T cell functional disorder resulting in increased plasma lymphocyte-derived permeability factors. In children with frequent relapses of nephrotic syndrome, the mechanism underlying the therapeutic efficacy of CD20 monoclonal antibodies in depleting B cells may provide additional evidence in exploring the critical role of B lymphocytes in INS pathogenesis. Previous studies have proposed that RTX bound to CD20 through antibody-dependent and complement-dependent cytotoxicity and led to lytic clearance of B cells. Additionally, RTX exerted an effect by blocking the interaction between B and T cells or regulating homeostasis and functions of T cell subsets. Recent studies on the development, differentiation, and activation of B-lymphocytes in glomerular diseases have suggested that the B-lymphocytes participate in the INS pathogenesis through interaction with T cells, secretion of antibodies, or production of cytokines. In this study, we aimed to provide a detailed description of the current knowledge on the development, differentiation, activity, functions, and related regulating factors of B cells involved in INS. Thus, further understanding of the immunopathogenesis of INS may offer some opportunities in precisely targeting B cells during therapeutic interventions. IMPACT: The topic "B cells play a role in glomerular disease" is a novel point, which is not completely described previously. We described interactions between T and B cells and immunoglobulin, IgG, IgM, IgE, etc. as well in glomerular disease. The research of regulatory factors associated with B cell's function, like BAFF, is a hot topic in other diseases; however, it is rare in glomerular disease.

A review of nephrotic syndrome and atopic diseases in children

Pediatric nephrotic syndrome (NS) is a common and recurrent glomerular disease in childhood. Furthermore, 50–70% of children with NS have increased total IgE in peripheral blood and a variety of clinical manifestations of atopic diseases. Hence, NS has many similarities with atopic diseases. However, no study has revealed a clear link between these two diseases. The present review discusses the correlation between pediatric NS and atopic diseases in children from three aspects: pathogenesis, cytokine change, and treatment. There are similar changes in T cells in terms of pathogenesis, with Th1/Th2 dysfunction and Treg cell function downregulation. Cytokine changes are similar and manifest as an increase in Th2 cytokines, TNF-α and TGF-β1, and a decrease in IL-10. Glucocorticoids, immunosuppressants and biological agents are used for the treatment of these two diseases. Therefore, it was speculated that NS and atopic diseases may be the same kind of disease, have a similar pathogenesis, and only exhibit different clinical manifestations due to different affected parts of the disease.

Mild electrical stimulation with heat shock attenuates renal pathology in adriamycin-induced nephrotic syndrome mouse model

Nephrotic syndrome (NS) is a renal disorder that is characterized by massive proteinuria, hypoalbuminemia and edema. One of the main causes of NS is focal segmental glomerulosclerosis (FSGS), which has extremely poor prognosis. Although steroids and immunosuppressants are the first line of treatment, some FSGS cases are refractory, prompting the need to find new therapeutic strategies. We have previously demonstrated that an optimized combination treatment of mild electrical stimulation (MES) and heat shock (HS) has several biological benefits including the amelioration of the pathologies of the genetic renal disorder Alport syndrome. Here, we investigated the effect of MES + HS on adriamycin (ADR)-induced NS mouse model. MES + HS suppressed proteinuria and glomerulosclerosis induced by ADR. The expressions of pro-inflammatory cytokines and pro-fibrotic genes were also significantly downregulated by MES + HS. MES + HS decreased the expression level of cleaved caspase-3 and the number of TUNEL-positive cells, indicating that MES + HS exerted anti-apoptotic effect. Moreover, MES + HS activated the Akt signaling and induced the phosphorylation and inhibition of the apoptotic molecule BAD. In in vitro experiment, the Akt inhibitor abolished the MES + HS-induced Akt-BAD signaling and anti-apoptotic effect in ADR-treated cells. Collectively, our study suggested that MES + HS modulates ADR-induced pathologies and has renoprotective effect against ADR-induced NS via regulation of Akt-BAD axis.

Rituximab Use in the Management of Childhood Nephrotic Syndrome

Childhood nephrotic syndrome is a challenging and often persistent renal disorder, and its incidence varies between different ethnicities and regions. Corticosteroids have been the main treatment for decades and are effective in most children with idiopathic NS, although 10-15% of these children become steroid resistant. Furthermore, some initially steroid sensitive children follow a steroid dependent or frequently relapsing course and are therefore at increased risk for developing steroid toxicity. In such children, alternative immunosuppressive medications are used to induce and/or maintain remission of NS. One such drug, rituximab, is a monoclonal antibody directed against the B lymphocyte CD20 marker which induces depletion of B cells, and has shown promising results in the management of NS in children. In this review, we summarize recent studies on the efficacy and safety of rituximab in the different types of childhood nephrotic syndrome, the known and potential mechanisms of action of rituximab, its possible complications and side effects, and the available and potential biomarkers of rituximab activity.

Successful Treatment of Focal Segmental Glomerulosclerosis Recurrence in a Second Kidney Transplant Patient: A Case Report

BACKGROUND

Recurrence of focal segmental glomerulosclerosis (FSGS) in renal allograft recipients after first transplant occurs in the second graft in virtually all patients. There is little evidence regarding optimal treatment.

CASE PRESENTATION

A 55-year-old man with primary FSGS and disease recurrence in both the first and the second kidney grafts is presented. In 1999, the patient developed FSGS 3 years after transplant, which was treated with plasmapheresis and cyclophosphamide. Hemodialysis was started at 8 years from the onset of relapse. In February 2014, the patient received a second kidney transplant, and after 2 weeks laboratory analysis showed nephrotic proteinuria (5.9 g/d) with increased serum creatinine. Biopsy results revealed recurrence of FSGS. At that time, he was treated with steroids and plasmapheresis with partial efficacy, achieving a serum creatinine level of 1.1 mg/dL with decreased proteinuria (1 g/d). After 4 months, creatinine worsened (1.6 mg/dL) with new evidence of proteinuria. Second biopsy results showed evidence of FSGS progression. The patient then received plasmapheresis and 2 doses of rituximab. Follow-up was characterized by progressive remission up to complete resolution. The patient is currently free from relapses after 3 years with good renal function and almost no proteinuria.

CONCLUSIONS

More evidence and prospective studies are needed to better understand the role of rituximab in FSGS in order to obtain an optimized therapeutic protocol for recurrence of FSGS in renal transplant recipients.

Rituximab in The Management of Pediatric Steroid-Resistant Nephrotic Syndrome: A Systematic Review

OBJECTIVES

To evaluate the efficacy and safety of rituximab in children with steroid-resistant nephrotic syndrome.

STUDY DESIGN

A systematic review evaluating the efficacy and safety of rituximab in children with steroid-resistant nephrotic syndrome was performed. Data from studies, performed before April 2017 were collected, from MEDLINE, Cochrane Library, Scopus, and Web of Science. Study eligibility criteria included clinical trials and observational studies with a minimal sample size of 5 patients, regarding treatment with rituximab in children with steroid-resistant nephrotic syndrome. Independent extraction of articles by 2 investigators using predefined data fields was performed.

RESULTS

We included 7 case series and 1 open-label randomized controlled trial. Among them, 3 studies were multicenter. A total of 226 patients were included. Mean age at onset was 5.6 ± 1.1 years. Mean number of rituximab administrations was 3.1 ± 1.1 infusions per patient. Remission was observed in 89 patients (46.4%). Remission was seen in 40.8% patients with initial steroid-resistant nephrotic syndrome and 52.8% patients with late steroid-resistant nephrotic syndrome. Good initial response to rituximab therapy was observed in 63.2% patients with minimal change nephrotic syndrome, 39.2% patients with focal and segmental glomerulosclerosis, 1 patient had diffuse mesangial hypercellularity, and 1 patient had IgM nephropathy. Sustained remission ranged from 18% to 93.7%. Five serious adverse events were observed.

CONCLUSIONS

Rituximab exhibited a satisfactory profile regarding efficacy and safety indicating that this agent is a promising therapy for steroid-resistant nephrotic syndrome and should be further investigated by randomized clinical trials.

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.

Steroid-resistant nephrotic syndrome: past and current perspectives

Patients with steroid-resistant nephrotic syndrome (SRNS) represent a challenging subset of patients with nephrotic syndrome who often fail standard immunosuppression and have a higher likelihood of progressing to end-stage renal disease. Appropriate treatment of SRNS requires an adequate understanding of the historical treatment, renal histopathology, and genetics associated with the disease. The aim of this review is to present a comprehensive appraisal of the history, role of renal biopsy, genetics, and treatment of SRNS.

Recent Advances in Treatments of Primary Focal Segmental Glomerulosclerosis in Children

Focal segmental glomerulosclerosis (FSGS) is a nephrotic syndrome. Up to around 80% of cases of primary FSGS are resistant to steroid treatment. A large proportion of patients with steroid-resistant FSGS progress to end-stage renal disease. The purpose of treatment is to obtain a complete remission of proteinuria, a necessary step that precedes improved renal survival and reduces the risk of progression to chronic kidney disease. When this is not possible, the secondary goal is a partial remission of proteinuria. Reduction or remission of proteinuria is the most important factor predictive of renal survival. We will review the current updated strategies for treatment of primary FSGS in children, including traditional therapies consisting of corticosteroids and calcineurin inhibitors and novel therapies such as rituximab, abatacept, adalimumab, and fresolimumab.