Comparison of the response of frequently relapsing steroid-dependent minimal change nephrotic syndrome to rituximab therapy between childhood-onset and adult-onset disease

Japanese clinical practice patterns of rituximab treatment for minimal change disease in adults 2021: A web-based questionnaire survey of certified nephrologists

BACKGROUND

In Japan, rituximab (RTX) for adult-onset frequently relapsing (FR)/steroid-dependent (SD) minimal change disease (MCD) is not explicitly reimbursed by insurance, and its standard regimen has not been established.

METHODS

We conducted a cross-sectional web-based survey between November and December 2021. The participants were nephrologists certified by the Japanese Society of Nephrology and answered 7 items about RTX for adult MCD. Factors related to the experience of RTX administration at their facilities were estimated by generalized estimating equations.

RESULTS

Of 380 respondents, 181 (47.6%) reported the experience of RTX use for adult MCD at their current facilities. Those who worked at university hospitals (vs. non-university hospitals, proportion difference 13.7%) and at facilities with frequent kidney biopsies (vs. 0 cases/year, 19.2% for 1-40 cases/year; 37.9% for 41-80 cases/year; 51.9% for ≥ 81 cases/year) used RTX more frequently. Of 181 respondents, 28 (15.5%) answered that there was no insurance coverage for RTX treatment. Of 327 respondents who had the opportunity to treat MCD, which was a possible indication for RTX, 178 (54.4%) indicated withholding of RTX administration. The most common reason was the cost due to lack of insurance coverage (141, 79.2%). Regarding RTX regimens for FR/SD MCD, introduction treatment with a single body surface area-based dose of 375 mg/m2 and maintenance treatment with a 6-month interval were the most common.

CONCLUSION

This survey revealed the nephrologists' characteristics associated with RTX use, the barriers to RTX use, and the variation in the regimens for adult MCD in Japan.

Review of the Role of Rituximab in the Management of Adult Minimal Change Disease and Immune-Mediated Focal and Segmental Glomerulosclerosis

Background

Minimal change disease and primary FSGS are podocytopathies but are also immune-mediated diseases. Rituximab acts via multiple mechanisms by tilting the balance between autoreactive B and T cells in favor of regulatory B and T cells. The consequences are decreased production of cytokines, chemokines, and permeability factors by these cells. In the past decade, we have seen the discovery of autoantibodies mediating nephrotic syndrome (anti-annexin A2 antibody, anti-UCHL1 antibody, and anti-nephrin antibody), and rituximab decreases their production. Rituximab also binds to podocyte SMPDL3b and has direct podocyte actions.

Summary

Rituximab's role in managing these primary podocytopathies has been discussed in this brief review. Rituximab has been used extensively in children and adults with frequently relapsing and steroid-dependent nephrotic syndrome. However, rituximab is not very promising in adult steroid-resistant nephrotic syndrome. Although ofatumumab would cause prolonged B-cell depletion and is fully humanized, it is unclear if it is superior to rituximab in preventing relapse of nephrotic syndrome.

Key Messages

Rituximab therapy can induce prolonged remission in adults with frequently relapsing and steroid-dependent nephrotic syndrome. However, no good data exist on using rituximab in steroid-resistant nephrotic syndrome.

Sequential rituximab therapy sustains remission of nephrotic syndrome but carries high risk of adverse effects

BACKGROUND

Sequential rituximab (RTX) administration has emerged as an important strategy to sustain remission of disease in patients with difficult-to-treat nephrotic syndrome.

METHODS

We report the efficacy and safety of sequential therapy with two or more courses of intravenous RTX in 250 patients with difficult-to-treat steroid dependence (n = 127) and calcineurin inhibitor (CNI)-dependent or CNI-refractory steroid resistance (n = 123) managed at one center during 2015-2021. Subsets of patients were cross-sectionally tested for hypogammaglobulinemia, seroprotection against and hyporesponsiveness to vaccines for hepatitis B and tetanus, BK/JC viruria and human antichimeric antibodies (HACAs).

RESULTS

Sequential RTX therapy, initiated at a median of 10 years [interquartile range (IQR) 7.3-14.4], was administered for 1.8 courses/person-year [95% confidence interval (CI) 1.7-2.0] over 2.0 years (95% CI 1.2-3.0). Therapy was associated with postponement of relapses by a median of 3 years in patients with steroid-sensitive disease and 2 years in those with steroid resistance. Relapses were reduced by a mean of 2.0 relapses/person-year (95% CI 1.8-2.2), enabling a reduction in prednisolone dose to 0.04 mg/kg/day (95% CI 0.01-0.11) and withdrawal of additional immunosuppression in 154 (62%) patients. RTX-associated adverse events, occurring at 0.20 events/person-year (95% CI 0.17-0.23), were chiefly comprised of infusion reactions (n = 108) and infections (n = 46); serious adverse events were observed in 10.8% patients, at 0.03 events/person-year (95% CI 0.02-0.05). Hypogammaglobulinemia was observed in 35% of 177 patients and was moderate to severe in 8.5% of cases. Rates of seroprotection at baseline and response following vaccination were lower for hepatitis B [1.9% and 29.4% (n = 52)] than tetanus [65.5% and 34.5% (n = 58)]. BK/JC viruria, without viremia, was observed in 7.3% of 109 cases. A total of 19 of 107 patients (17.8%) had HACAs, which were associated with B cell nondepletion and serum sickness. Age at therapy of <9-10 years was associated with a risk of early relapse, treatment failure and hypogammaglobulinemia following RTX therapy.

CONCLUSIONS

Sequential therapy with RTX effectively reduces relapses in patients with difficult-to-treat steroid- and/or CNI-dependent or CNI-refractory nephrotic syndrome. Therapy is associated with high rates of hypogammaglobulinemia and infusion reactions.

Rituximab Use for the Treatment of Childhood Nephrotic Syndrome by Canadian Pediatric Nephrologists: A National Survey

Background:

There is known practice variation in the treatment of frequently relapsing, steroid-dependent, and steroid-resistant nephrotic syndrome in children. Rituximab is an emerging therapy for difficult-to-treat nephrotic syndrome; however, there are no clear treatment guidelines. We therefore hypothesized that a wide variety of approaches to this therapy exist.

Objective:

To evaluate when and how rituximab is used for the treatment of childhood nephrotic syndrome in Canada.

Design and setting:

An online survey was used.

Participants:

Canadian pediatric nephrologists.

Methods:

A cross-sectional survey was distributed across Canada through the Canadian Association of Pediatric Nephrologists (CAPN) to evaluate rituximab treatment practices.

Results:

Of a total of 20 responses, 19 (95%) use rituximab in the treatment of nephrotic syndrome, usually as a third or fourth agent. For the number of rituximab doses, the majority (68%) uses 2 doses each time they use it. Eighteen respondents (90%) measure B cells when using this medication, mostly monthly (50%) or every 3 months (39%). Respondents were administered additional doses of rituximab prophylactically (74%) or at first relapse (47%). Long-term drug safety and drug funding were identified as the main barriers to rituximab use.

Limitations:

This survey represents the practice styles of physicians in a single country, and there is a nonresponse bias of 63%. Also, associations were not calculated.

Conclusions:

Among Canadian pediatric nephrologists, rituximab use for nephrotic syndrome appears to be increasing, but significant practice variations remain, including approaches to B-cell monitoring. It is reserved mostly for second-line and third-line use due to cost, funding issues, and residual uncertainty regarding long-term safety. Understanding these critical areas of practice uncertainty is a first step to optimize treatment of nephrotic syndrome in children.

Clinical significance of T lymphocyte subsets, immunoglobulin and complement expression in peripheral blood of children with steroid-dependent nephrotic syndrome/frequently relapsing nephrotic syndrome

OBJECTIVE

To investigate the clinical significance of T lymphocyte subsets, immunoglobulin and complement expression in the peripheral blood of children with steroid-dependent nephrotic syndrome/frequently relapsing nephrotic syndrome (SDNS/FRNS).

METHODS

A prospective study was conducted on 285 children with nephrotic syndrome (NS). Among the 285 patients, 187 children had steroid-sensitive nephrotic syndrome (SSNS) and 98 children had SDNS/FRNS according to their sensitivity to hormones. Meanwhile, 50 healthy children in the same period were selected as the control group. Serum albumin (ALB), blood urea nitrogen (BUN), serum creatinine (SCr), estimated glomerular filtration rate (eGFR), high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), CD3+, CD4+, CD8+, immunoglobulin IgA, IgG, IgM and complement C3 and C4 were measured upon admission, and the content of urinary CD80 was also determined.

RESULTS

Compared with the control group, BUN, SCr, hs-CRP and IL-6 levels, urinary CD80, IgA, IgM and C3 in the SDNS/FRNS and SSNS groups were significantly higher, while ALB, eGFR, CD3+, CD4+, CD4+/CD8+, IgG and IgG/IgM were significantly lower (all P<0.05). Compared with the SSNS group, BUN, SCr, hs-CRP and IL-6 levels in the SDNS/FRNS group were significantly higher, while ALB and eGFR levels were significantly lower (all P<0.05). Compared with the SDNS/FRNS group, IgM in the SSNS group was significantly lower, while CD4+/CD8+, urinary CD80 and IgG/IgM were significantly higher (all P<0.001).

CONCLUSION

Renal function decline and inflammatory response existed in children with NS. CD3+, CD4+, CD4+/CD8+ and IgG/IgM in peripheral blood were decreased, while IgA, IgM, C3 and urinary CD80 were increased. Moreover, renal function decline, increase of inflammatory factors, decrease of IgG/IgM and CD4+/CD8+ were more obvious in the SDNS/FRNS group.

The Efficacy and Safety of Rituximab for Childhood Steroid-Dependent Nephrotic Syndrome: A Systematic Review and Meta-Analysis

Objectives: Rituximab (RTX), a possible alternative treatment option, is recognized as a new therapeutic hope for the treatment of steroid-dependent nephrotic syndrome (SDNS) in children. However, the efficacy and safety of RTX in the treatment of childhood SDNS are still controversial. The objective of this study was to evaluate the efficacy and safety of RTX treatment in children with SDNS. Study Design: Six randomized controlled trials (RCTs) and one retrospective comparative control study data from studies, performed before January 2021 were collected, from PubMed, Cochrane Library, Embase, and Web of Science. The studies evaluating the efficacy and safety of RTX in childhood SDNS were included. Results: Six RCTs and one retrospective comparative control study were included in our analysis. Compared with the control group, the RTX treatment group achieved a higher complete remission rate (OR = 5.21; 95% CI, 3.18-8.54; p < 0.00001), and we found significant differences between the two groups on serum albumin level (MD = 0.88; 95% CI, 0.43-1.33; p = 0.0001) and estimated glomerular filtration rate (MD = 6.43; 95% CI, 2.68-10.19; p = 0.0008). However, RTX treatment did not significantly lower serum creatinine levels nor did it significantly reduce the occurrence of proteinuria. In addition, we found no advantages with RTX on treatment safety. Conclusions: RTX has shown satisfactory characteristics in terms of efficacy and may be a promising treatment method for SDNS in children. However, the long-term effects have not been fully evaluated and should be further studied through randomized clinical trials.

Efficacy and safety of rituximab in adult frequent-relapsing or steroid-dependent minimal change disease or focal segmental glomerulosclerosis: a systematic review and meta-analysis

Background

The efficacy and safety of rituximab (RTX) in adult frequent-relapsing (FR) or steroid-dependent (SD) nephrotic syndrome (NS), including minimal change disease (MCD) or focal segmental glomerulosclerosis (FSGS), are still inconclusive.

Methods

We performed a systematic review and meta-analysis registered in  PROSPERO (CRD42019148102) by pooling data of cohort studies or case series on adult patients with difficult-to-treat NS. Steroid-resistant NS was excluded. The primary outcomes were the complete remission (CR) rate and the relapse rate. Partial remission (PR) rate, no response (NR) rate and adverse events were the secondary outcomes. A random-effects model was performed for all the outcomes.

Results

We included 21 studies involving 382 adult MCD/FSGS subjects with a median follow-up duration from 12 to 43 months. RTX treatment induced a pooled 84.2% CR rate [95% confidence interval (CI): 67.7–96.3%], while MCD patients had a high 91.6% CR rate and FSGS patients a moderate 43% CR rate. However, 27.4% (95% CI 20.7–34.5%) of the patients relapsed during the follow-up. The pooled PR and NR rates were 5.8% (95% CI 1.2–12.5%) and 5.2% (95% CI 0.0–15.0%), respectively. RTX was associated with trivial adverse events and good tolerance.

Conclusions

In summary, by pooling results of current pilot studies, RTX may be an effective and relatively safe alternative for most adult FR or SD MCD/FSGS to displace calcineurin inhibitors or prednisone in the hierarchy of treatment. More clinical trials comparing RTX with other immunosuppressants and concerning the long-term adverse events are needed.

Comparison of treatment options in adults with frequently relapsing or steroid-dependent minimal change disease

Background

Studies comparing all treatment options for frequently-relapsing/steroid-dependent (FR/SD) minimal change disease (MCD) in adults are lacking.

Methods

Medical records of 76 adults with FR/SD MCD who were treated with corticosteroids as the first-line therapy were reviewed. Treatment options were compared for the time to relapse, change of therapy and progression (relapse on full-dose treatment).

Results

Second-line treatments included rituximab (RTX; n = 13), mycophenolate mofetil (MMF; n = 12), calcineurin inhibitors (CNI; n = 26) and cyclophosphamide (CTX; n = 16). During the second-line treatments, 48 (71.6%) patients relapsed at median 17 (range 2–100)  months. The majority of relapses occurred during dose tapering or off drug. Twenty of 65 (30.8%) changed therapy after the first relapse. The median time to relapse after the second line was 66 versus 28 months in RTX versus non-RTX groups (P = 0.170). The median time to change of treatment was 66 and 44 months, respectively (P = 0.060). Last-line treatment options included RTX (n = 8), MMF (n = 4), CNI (n = 3) and CTX (n = 2). Seven (41.2%) patients had a relapse during the last-line treatment at median 39 (range 5–112)  months. The median time to relapse was 48 versus 34 months in the RTX versus non-RTX groups (P = 0.727). One patient in the RTX group died presumably of heart failure. No major adverse event was observed. During the median follow-up of 81 (range 9–355)  months, no patients developed end-stage renal disease.

Conclusions

Relapse is frequent in MCD in adults. Patients treated with RTX may be less likely to require a change of therapy and more likely to come off immunosuppressive drugs.

Usefulness of the cytokines expression of Th1/Th2/Th17 and urinary CD80 excretion in adult-onset minimal change disease

Background

Minimal change disease (MCD) is a common form of nephrotic syndrome in adults. However, the molecular mechanism underlying the pathogenesis of MCD remains incompletely understood. In this study, we aimed to investigate the role of the cytokines expression of Th1/Th2/Th17 and urinary CD80 excretion in adult-onset MCD patients.

Methods

The lymphocyte subsets, 34 cytokine levels of Th1/Th2/Th17, serum and urine concentrations of CD80, and expression of CD80 in glomeruli were analyzed in 28 cases (15 males and 13 females; average age: 34.1 years, age range: 18–56 years), including 10 patients with MCD in relapse, nine patients with MCD in remission and nine healthy controls.

Results

There was no significant difference of CD3⁺CD4⁺ cells proportion among patients with MCD in relapse, MCD in remission and healthy controls (P = 0.802). The cytokine levels of GM-CSF and tumor necrosis factor (TNF)-related activation-induced cytokine (TRANCE) in patients with MCD in relapse increased 1.5 times higher than those in remission. An evident increase in the excretion of urinary CD80 was found in patients with relapsed MCD compared with those in remission (598.4 ± 115.8 vs 81.78 ± 7.04 ng/g creatinine, P < 0.001) and healthy controls (598.4 ± 115.8 vs 67.44 ±  8.94  ng/g creatinine, P < 0.001). CD80 expression was observed in podocyte of MCD patient in relapse by immunofluorescence technique.

Conclusions

The cytokines GM-CSF and TRANCE are increased and the urinary CD80 levels are elevated in adult-onset MCD patients in relapse, indicating a disorder of Th1/Th2/Th17 balance and that the elevated excretion of CD80 may underlie the pathogenesis and development of adult-onset MCD.

Low-Density Lipoprotein Apheresis in Patients with Acute Kidney Injury Due to Minimal Change Disease Requiring Acute Renal Replacement Therapy

Low-density lipoprotein apheresis (LDL-A) has been developed as a therapy for familial hypercholesterolemia, but LDL-A has also been used as a general treatment for drug-resistant nephrotic syndrome (NS) due to focal segmental glomerulosclerosis (FSGS). The patients with NS due to minimal change disease (MCD) are often difficult to control effective circulating plasma volume, causes acute kidney injury (AKI), and when diuretics are not effective and the respiratory condition of patients worsens, patients require acute renal replacement therapy (ARRT). The effectiveness of LDL-A is not only reduction of serum low-density lipoprotein but also various other benefits. LDL-A might have improved renal hemodynamics by reducing vasoconstrictive eicosanoids and contributed to the therapeutic effect of antiproteinuric drugs such as corticosteroids. We treated a 49-year-old Japanese woman and a 71-year-old Japanese man with AKI caused by NS due to MCD, who required ARRT. Although these patients received ARRT and corticosteroids, their AKI and MCD did not improve sufficiently. We initiated LDL-A treatment for these patients as an additional treatment modality, because their total serum cholesterol levels were high at the time of admission. After the additional LDL-A treatment, both patients were able to discontinue ARRT, because NS and AKI in both patients were improved sufficiently. It is possible that early additional LDL-A is effective for patients with AKI and NS due to MCD who require ARRT, and may help patients discontinue ARRT because of the effect of LDL-A such as improving hypercoagulability and renal hemodynamics and contributing to the therapeutic effect of corticosteroids.

Rituximab therapy in adults with steroid-dependent nephrotic syndrome

INTRODUCTION

Patients with steroid-dependent nephrotic syndrome (SDNS) suffer frequent relapse with adverse effects caused by long-term prednisolone treatment. Recently, the chimeric monoclonal antibody against the protein CD20 (rituximab - RTX) was observed to be efficacious and safe in the treatment of patients with SDNS. We summarized the scientific literature to evaluate RTX therapy in the clinical management of SDNS.

MATERIAL AND METHODS

PubMed, EMBASE, and Cochrane Library databases were investigated from interception to 2019-6-6, without language limitation. The analysis was restricted to adults ≥ 19 years of age. Data were administered and analyzed through the Review manager 5.3 software.

RESULTS

After RTX treatment, relapse times, prednisolone dose, and proteinuria decreased, whereas serum albumin was increased. The clinical parameters blood pressure and total cholesterol diminished also, whereas bone mineral density was improved. Overall, RTX ameliorated the adverse effects of prednisolone. Moreover, the Th1/Th2 ratio was changed except for the CD19 and CD20 cell counts. Additionally, most of the adverse effects of RTX were mild and well tolerated.

CONCLUSIONS

In the studies that we considered, we concluded that RTX treatment was effective and safe in the therapy of patients with SDNS. Nevertheless, more randomized controlled trials are required to explore the mechanism of RTX action and verify its efficacy.

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.