Age and memory B cells at baseline are associated with risk of relapse and memory B-cell reappearance following anti-CD20 treatment in pediatric frequently-relapsing/steroid-dependent nephrotic syndrome

Risk factors and retreatment for relapse in childhood primary nephrotic syndrome treated with rituximab

BACKGROUND

The effectiveness of rituximab (RTX) for steroid-dependent/frequently relapsing nephrotic syndrome (SDNS/FRNS) in children is well documented. However, there are insufficient data on relapse risk factors. Additionally, the retreat regimen for relapsed children requires further investigation.

METHODS

We administered single dose RTX (375 mg/m2, maximum 500 mg) to children with SDNS/FRNS between May 2020 and December 2022. An additional single dose of RTX was administered when B-cell depletion (CD19 + B cells < 1%) was incomplete or B-cell recovery (CD19 + B cells ≥ 1%) occurred. Primary and secondary outcomes were the first and second relapse, respectively.

RESULTS

Eighty-nine patients were included and the observation period was 12.2-43.2 months. Thirty-three patients (37.1%) relapsed after RTX treatment. Multivariate analysis showed that previous steroid-resistant nephrotic syndrome (SRNS) history and low NK-cell percentage at initial RTX treatment were independent risk factors for first relapse. In the relapse group, 26 patients (78.8%) continued RTX treatment upon B-cell recovery. During mean follow-up period of (15.4 ± 8.1) months, 15 patients (45.5%) experienced a second relapse. Compared with non-continued RTX treatment group, the continued RTX treatment group had a lower relapse rate (34.6% (9/26) versus 85.7% (6/7); P = 0.047) and fewer relapses (0.0 (0.0, 0.6) versus 1.8 (0.9, 2.7) times/year; P = 0.004). Multivariate analysis showed that continued RTX treatment was the protective factor for second relapse.

CONCLUSION

Previous SRNS history and low NK-cell percentage at initial RTX treatment may be associated with higher risk of relapse. Despite the possibility of relapse during RTX treatment, continued RTX treatment is effective in reducing relapse.

The efficacy and dynamic changes of immune function of rituximab with mycophenolate mofetil in the treatment of steroid-dependent /frequently relapsing nephrotic syndrome: a retrospective follow-up study

INTRODUCTION

Approximately 70%～90% of children with steroid-sensitive nephrotic syndrome (SSNS) will suffer from steroid dependency or frequent relapses, prompting the use of steroid-sparing agent. In this study, we investigate the efficacy and the characteristics of dynamic changes in immune function of two doses of rituximab (RTX) in the treatment of steroid-dependent/frequently relapsing nephrotic syndrome (SDNS /FRNS).

METHOD

Retrospective follow-up study was conducted in our hospital from June 2022 to September 2023. 7 children with SDNS /FRNS were allocated to intravenous 2 doses RTX (each dose 375mg/m2, 1 dose per week) and administered the standard oral dose of mycophenolate mofetil (MMF) (1000-1200/m2/d, divided into 2 doses) when B cells have recovered (≥ 5/ul). The study subjects after treatment were monitored for the efficacy and dynamic changes of immune function for 12 months.

RESULT

7 children with SDNS/FRNS who were treated RTX with MMF and followed up for 12 months have no relapse. The rate of B cell depletion (< 5/ul) was 100% at 1 week after the second dose of RTX treatment, and the rate of B cell recovery was 100% at 5-12 months after the first dose of RTX treatment. There was no significant difference with T cell subsets (CD3, CD4, CD8, CD4/CD8) at each follow-up time points (all P > 0.05). The count of NK cells was significantly higher than that of other groups at 1 week after the second dose (P < 0.05). The IgM level at 1 week after the second dose was significantly lower than that before treatment and 1 week after the first dose (P < 0.05). There were no significant differences with IgA, IgG, C3 and C4 before treatment, 1 week after the first dose and 1 week after the second dose (all P > 0.05).

CONCLUSION AND RECOMMENDATION

Administering two doses of RTX along with the standard dose of MMF has been effective in maintaining remission for children with SDNS/FRNS. B cell depletion can be achieved one week after the second dose of RTX treatment. NK cell proliferation may play a role in B cell depletion, and early B cell depletion may suppress the production of IgM. These findings require further validation through additional clinical trials and basic research.

Comparison of B lymphocyte profile between membranous nephropathy and idiopathic nephrotic syndrome pediatric patients

BACKGROUND

Membranous nephropathy (MN) and idiopathic nephrotic syndrome (INS) are two B-cell mediated rare glomerular diseases that benefit from treatment with B-cell depleting anti-CD20 monoclonal antibody rituximab. Different B-cell dysregulations have been described in pediatric INS patients and in adults affected by MN. In adult MN patients, an increased level of mature-naïve cells and atypical memory B cells and a significant reduction in IgM memory and switched memory B cells have been previously described compared to healthy individuals. To date, there is no information available about B-cell immunophenotyping in pediatric MN.

METHODS

In this monocentric retrospective case-control study, we analyzed by flow cytometry the B-cell profile in rituximab-naïve (n = 15) children affected by MN, compared with pediatric INS patients (n = 15) selected by propensity score matching, and both evaluated during active disease. Age-matched controls (n = 15) with non-immune-mediated kidney diseases were also characterized. Demographical, clinical, laboratory, and immunosuppressive treatment data were registered.

RESULTS

We found that children with MN and INS had significantly higher circulating levels of total CD19+, mature-naïve, and atypical memory B cells and similar levels of transitional B cells when compared to age-matched controls. Circulating levels of total memory B cells, IgM memory B cells, and plasmablasts/plasmacells were significantly higher in INS patients compared to both MN patients and age-matched controls.

CONCLUSIONS

Our study indicated that children affected by MN had a specific B-cell profile and that high levels of memory B-cell subsets are specific to INS pediatric patients independently of proteinuria intensity.

Childhood idiopathic nephrotic syndrome: recent advancements shaping future guidelines

Childhood idiopathic nephrotic syndrome is an important pediatric kidney disease associated with significant morbidities and even mortality. Several guidelines have been developed to standardize the terminology and patient care among the pediatric nephrology community. Since the publication of these guidelines, there have been major breakthroughs in the disease management and the understanding of underlying pathogenesis through multi-omics investigations, including the identification of anti-nephrin autoantibodies, genetic susceptibility loci, and the pathogenic role of B cell subsets. In this educational review, we summarize the recent major advancements in idiopathic nephrotic syndrome and attempt to provide potential therapeutic approaches in both steroid-sensitive and steroid-resistant nephrotic syndrome that may shape future guideline development.

The Pathogenesis of Nephrotic Syndrome: A Perspective from B Cells

Background

Nephrotic syndrome is a special type of chronic kidney disease, the specific pathogenesis of which remains unclear. An increasing number of studies have suggested that B cells play an important role in the pathogenesis of nephrotic syndrome.

Summary

Idiopathic nephrotic syndrome is a common kidney disease in children. While previously believed to be primarily caused by T-cell disorders, recent research has shifted its focus to B cells. Studies have shown that B cells play a significant role in the pathogenesis of NS, potentially even more so than T cells. This article provides a comprehensive review of the involvement of B cells in the development of idiopathic nephrotic syndrome.

Key Messages

B cells are involved in the pathogenesis of nephrotic syndrome by producing autoantibodies and various cytokines.

Case report: Effective treatment of rituximab-resistant minimal change disease with obinutuzumab in an adult

Background

Minimal change disease (MCD) is a common cause of adult nephrotic syndrome. Most adults with MCD achieve complete remission (CR) after initial steroid therapy. However, approximately 30% of adults who respond to steroids experience frequent relapses, becoming steroid-dependent and potentially developing refractory MCD. Treating refractory MCD in adults poses a significant challenge.

Main body

A 37-year-old woman presented to the nephrology department with a 6-year history of MCD. The diagnosis of MCD was confirmed via renal biopsy. She initially achieved CR with steroid treatment but experienced relapse during steroid tapering. Subsequent CR was achieved with a regimen of steroids and tacrolimus although multiple relapses occurred. Rituximab led to another CR, but its maintenance lasted only 6 months. The response to subsequent rituximab treatments was unsatisfactory. Ultimately, obinutuzumab was selected, resulting in the induction and maintenance of CR for 12 months.

Conclusions

This case demonstrates the successful treatment of frequently relapsed, steroid-dependent, and rituximab-resistant MCD with obinutuzumab. Obinutuzumab is a promising therapeutic option for rituximab-resistant MCD.

Rituximab versus tacrolimus as corticosteroid-sparing therapy for children with steroid-dependent nephrotic syndrome: A systematic review and meta-analysis of randomized and nonrandomized controlled trials

Objectives

Prolonged use of corticosteroids induced complicated course in children with steroid-dependent nephrotic syndrome (SDNS), and the use of tacrolimus, a first-line alternative calcineurin inhibitor (CNI) agent was related to some unwanted adverse effects. Rituximab, a second alternative treatment has been proven to reliably reduce the number of relapses within 12 months with minimal adverse effects.

Materials and Methods

Our review follows Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. All the databases were derived from MEDLINE, Proquest, EBSCOhost, Wiley, and Google Scholar within the past 11 years. The risk of bias was evaluated using the Revised Cochrane Risk of Bias Tool for Randomized Trials (RoB 2) and Risk of Bias in Non-Randomized Studies of Interventions. Meta-analysis used Review Manager (version 5.4) with a random effect model to obtain a pooled mean difference (MD) and odds ratio with 95% confidence intervals (CIs).

Results

Four studies were included based on our eligibility criteria, and only three were included in the quantitative analysis. Three studies had low and one study had a moderate risk of bias. Pooled data results indicated that Rituximab was superior to tacrolimus in reducing the number of patients with 1-2 relapses (MD = 0.44, [95% CI: 0.21-0.91]) and had higher eGFR values (MD = 6.67; [CI - 2.92-10.61]). However, Rituximab showed insignificant superiority compared to tacrolimus in reducing the number of patients with 3 relapses, sustained remission, cumulative steroid use, serum cholesterol, and serum albumin concentrations.

Conclusion

Rituximab exhibits more advantages in treating SDNS compared to tacrolimus, although the treatment options are highly individualized. Both regimens must also be weighed against their potential side effects to achieve a better overall health status.

Can we effectively manage chronic kidney disease with a precision-based pharmacotherapy plan? Where are we?

INTRODUCTION

In recent years, thanks to significant advances in basic science and biotechnologies, nephrology has witnessed a deeper understanding of the mechanisms leading to various conditions associated with or causing kidney disease, opening new perspectives for developing specific treatments. These new possibilities have brought increased challenges to physicians, who face with a new complexity in disease characterization and selection the right treatment for individual patients.

AREAS COVERED

We chose four therapeutic situations: anaemia in chronic kidney disease (CKD), heart failure in CKD, IgA nephropathy (IgAN) and membranous nephropathy (MN). The literature search was made through PubMed.

EXPERT OPINION

Anaemia management remains challenging in CKD; a personalized therapeutic approach is often needed. Identifying patients who could benefit from a specific therapy is also an important goal for patients with CKD and heart failure with reduced ejection fraction. Several new treatments are under clinical development for IgAN; interestingly, they target specifically the pathogenetic mechanisms of the disease. The understanding of MN pathogenesis as an autoimmune disease and the discovery of several autoantibodies allows a better characterization of patients. High-sensible techniques for lymphocyte counting open the possibility of more personalized use of anti CD20 therapies.

Management of adult patients with podocytopathies: an update from the ERA Immunonephrology Working Group

The histopathological lesions, minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) are entities without immune complex deposits which can cause podocyte injury, thus are frequently grouped under the umbrella of podocytopathies. Whether MCD and FSGS may represent a spectrum of the same disease remains a matter of conjecture. Both frequently require repeated high-dose glucocorticoid therapy with alternative immunosuppressive treatments reserved for relapsing or resistant cases and response rates are variable. There is an unmet need to identify patients who should receive immunosuppressive therapies as opposed to those who would benefit from supportive strategies. Therapeutic trials focusing on MCD are scarce, and the evidence used for the 2021 Kidney Disease: Improving Global Outcomes (KDIGO) guideline for the management of glomerular diseases largely stems from observational and pediatric trials. In FSGS, the differentiation between primary forms and those with underlying genetic variants or secondary forms further complicates trial design. This article provides a perspective of the Immunonephrology Working Group (IWG) of the European Renal Association (ERA) and discusses the KDIGO 2021 Clinical Practice Guideline for the Management of Glomerular Diseases focusing on the management of MCD and primary forms of FSGS in the context of recently published evidence, with a special emphasis on the role of rituximab, cyclophosphamide, supportive treatment options and ongoing clinical trials in the field.