Adult survivors of childhood-onset steroid-dependent and steroid-resistant nephrotic syndrome treated with cyclosporine: a long-term single-center experience

BACKGROUND

Although evidence has confirmed that cyclosporine (CS) is efficacious against childhood-onset steroid-dependent and steroid-resistant nephrotic syndrome (SD/SRNS), some patients may continue to relapse during adulthood. However, predictive factors for adult active disease and kidney complications, such as chronic kidney disease (CKD) and hypertension, in this cohort remain unknown.

METHODS

We conducted a retrospective study on the long-term outcomes of 81 young adults with childhood-onset SD/SRNS treated with CS. The primary endpoint was the probability of active disease into adulthood. The secondary endpoint was the probability of developing kidney complications.

RESULTS

At the last follow-up (median age, 23.2 years; median disease duration, 15.8 years), 44 adult patients (54%) continued to have active disease, whereas 16 patients developed CKD or hypertension, respectively. The proportion of patients developing kidney complications was similar between the active disease and long-term remission groups. Young age at NS onset and history of relapse during the initial CS (median, 31 months) were independent predictive factors for active disease. Acute kidney injury at NS onset, focal segmental glomerulosclerosis, and irreversible CS nephrotoxicity were identified as risk factors for the development of CKD, whereas older age was identified as a risk factor for the development of CKD and hypertension.

CONCLUSIONS

More than 50% of adult survivors treated with CS continued to have active disease, and each 20% developed CKD or hypertension. A long-term follow-up is necessary for patients with SD/SRNS to identify the development of kidney complications later in adulthood that can be attributed to prior disease and CS treatment in childhood, irrespective of disease activity. A higher resolution version of the Graphical abstract is available as Supplementary information.

Association between the time of initial relapse and subsequent relapses in patients with childhood-onset idiopathic nephrotic syndrome

BACKGROUND

Nephrotic syndrome relapse within 6 months is a known risk factor for steroid-dependent nephrotic syndrome/frequently relapsing nephrotic syndrome (SDNS/FRNS), but the risk of early development of SDNS/FRNS and initiation of immunosuppression therapy remains unknown.

METHODS

Patients with childhood-onset idiopathic nephrotic syndrome who had the first relapse within 6 months were enrolled. We analyzed the relationship between the time of the first relapse or the time of initial remission and incidence of SDNS/FRNS or initiation of immunosuppression therapy.

RESULTS

Forty-five patients were enrolled. Twenty out of 23 patients (87%) with the first relapse within 30 days after discontinuing initial steroid therapy experienced a second relapse within 30 days after discontinuing steroid therapy. Additionally, most patients in this group (96%) experienced a second relapse within 6 months after the onset and were diagnosed as SDNS/FRNS at this time. In this group, the incidence of SDNS/FRNS development within 6 months was 96%. In contrast, the incidence of SDNS/FRNS development within 6 months was 18% in patients with the first relapse more than 30 days after steroid discontinuation. The incidence of initiation of immunosuppressive agents within 6 months was 83% in the former group and 14% in the latter group.

CONCLUSIONS

Most patients with the first relapse within 30 days after discontinuing steroid therapy developed SDNS/FRNS and were administered immunosuppressive agents within 6 months. Thus, it might be reasonable to start immunosuppression therapy in this group without waiting for the second relapse.

Predictive factors of long-term disease remission after rituximab administration in patients with childhood-onset complicated steroid-dependent nephrotic syndrome: a single-center retrospective study

BACKGROUND

Despite the fact that rituximab (RTX)-associated adverse events may be relatively frequent in younger patients, recent studies have reported RTX as a suitable first-line steroid-sparing agent for maintaining remission in children with steroid-dependent nephrotic syndrome (SDNS). However, the impact of age at RTX initiation on the long-term outcome remains unknown in this cohort.

METHODS

We retrospectively reviewed the clinical course of 61 patients with complicated SDNS who received a single dose of RTX (375 mg/m2) followed by maintenance immunosuppressive agents (IS) from January 2008 to March 2021. In patients who achieved > 12 months of prednisolone-free remission, IS tapering within 6 months was tried to achieve. The primary endpoint was the probability of achieving long-term treatment-free remission at the last follow-up.

RESULTS

After RTX initiation, 52 patients (85.2%) relapsed after a median of 665 days, and 44 patients (72.1%) received additional RTX doses (total, 226 infusions). At the last follow-up (median observation period, 8.3 years; median age, 18.3 years), 16 patients (26.2%) achieved long-term remission. Multivariate analysis showed that older age at RTX initiation was the independent predictive factor for achieving long-term remission (odds ratio, 1.25; p < 0.05). The proportion of those who achieved long-term remission was significantly higher in patients aged ≥ 13.5 years than in those aged < 13.5 years at RTX initiation (52.6 vs 14.3%, p < 0.05). Persistent severe hypogammaglobulinemia did not develop in older children (≥ 13.5 years) at RTX initiation.

CONCLUSION

For older children with complicated SDNS, RTX appeared to be a suitable disease-modifying therapy without persistent adverse events.

A successful treatment for chronic active Epstein-Barr virus disease with Nephrotic Syndrome

Chronic active Epstein-Barr virus (CAEBV) disease is more likely to occur when a patient is on immunosuppressive therapy for any disease or is susceptible to infection, and the prognosis is poor without appropriate treatment, including hematopoietic stem cell transplantation (HSCT). In addition to HSCT, several other chemotherapy regimens have been reported, but all of them are difficult to maintain in remission. Without HSCT, survival rates have been reported to be 50% in 5 years and 25% in 15 years. This is a report of a 13-year-old boy who developed CAEBV disease during cyclosporine A (CyA) treatment for the steroid-dependent nephrotic syndrome (SDNS). Since SDNS precluded HSCT or chemotherapy, CyA was tapered off based on the belief that alleviating his immunosuppressed state would decrease the CAEBV disease. We decided to gradually reduce the CyA dose to activate T-cell immunity, while periodically monitoring the EBV viral load. Finally, we found an appropriate dose that could suppress both CAEBV disease and SDNS, and it lasted for more than 9 years. No case has been reported to date in which a patient developed CAEBV disease while receiving immunosuppressive drugs for the primary disease, and both diseases were controlled only by reducing the dose of immunosuppressive drugs. In this report, we show that dose reduction of immunosuppressive agents without chemotherapy or HSCT is an effective option for the treatment of CAEBV disease in patients receiving immunosuppressive agents.

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.

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

Idiopathic nephrotic syndrome is the most frequent pediatric glomerular disease, affecting from 1.15 to 16.9 per 100,000 children per year globally. It is characterized by massive proteinuria, hypoalbuminemia, and/or concomitant edema. Approximately 85-90% of patients attain complete remission of proteinuria within 4-6 weeks of treatment with glucocorticoids, and therefore, have steroid-sensitive nephrotic syndrome (SSNS). Among those patients who are steroid sensitive, 70-80% will have at least one relapse during follow-up, and up to 50% of these patients will experience frequent relapses or become dependent on glucocorticoids to maintain remission. The dose and duration of steroid treatment to prolong time between relapses remains a subject of much debate, and patients continue to experience a high prevalence of steroid-related morbidity. Various steroid-sparing immunosuppressive drugs have been used in clinical practice; however, there is marked practice variation in the selection of these drugs and timing of their introduction during the course of the disease. Therefore, international evidence-based clinical practice recommendations (CPRs) are needed to guide clinical practice and reduce practice variation. The International Pediatric Nephrology Association (IPNA) convened a team of experts including pediatric nephrologists, an adult nephrologist, and a patient representative to develop comprehensive CPRs on the diagnosis and management of SSNS in children. After performing a systematic literature review on 12 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, recommendations were formulated and formally graded at several virtual consensus meetings. New definitions for treatment outcomes to help guide change of therapy and recommendations for important research questions are given.

Rituximab-induced serum sickness in a girl with nephrotic syndrome

Rituximab (RTX) has been used to treat B cell lineage lymphoma/leukemia or autoimmune or autoinflammatory disorders. RTX therapy has been extensively applied to cases of frequently relapsing nephrotic syndrome (FRNS) and steroid-dependent nephrotic syndrome. Rituximab-induced serum sickness (RISS) has been recognized as a rare severe type-3 hypersensitivity reaction in patients treated with RTX. We herein report a 10-year-old girl with RISS in FRNS. She was diagnosed with RISS based on characteristic symptoms, such as a fever, rash, arthritis, or proteinuria, during RTX therapy associated with a high level of human anti-chimeric antibody. Even after recovering from acute symptoms by RISS, she suffered from worsening relapses of nephrotic syndrome. The symptoms of RISS are non-specific, resembling viral infections, autoinflammatory diseases and Kawasaki disease, especially in children. While RISS is a rare complication among patients with nephrotic syndrome, it should be carefully considered as a severe complication in patients being treated with RTX.

Anti-rituximab antibodies in pediatric steroid-dependent nephrotic syndrome

BACKGROUND

Rituximab is a chimeric anti-CD20 monoclonal antibody that induces sustained remission in children with steroid-dependent nephrotic syndrome. However, there is no consensus on the optimal regimen and monitoring of rituximab. In other autoimmune diseases, anti-rituximab antibodies (ARA) have been reported in 10-40% of patients, but their clinical relevance remains unclear. In nephrotic syndrome, data are scarce.

METHODS

We report a single-center retrospective study with immuno- and pharmacological monitoring of rituximab treatment in children with frequent relapsing (FR) or steroid-dependent nephrotic syndrome (SDNS). We analyzed the monthly monitoring of 24 children, receiving a dose of rituximab (375 mg/m²) between December 2017 and April 2018 at the Pediatric Nephrology Department of Robert-Debré hospital, Paris.

RESULTS

ARA were detected in 7/24 patients (29%), sometimes after the first infusion of rituximab. ARA were present at baseline in two patients previously treated with rituximab. Both displayed no B-cell depletion. ARA were also reported in 5/22 patients during follow-up, with antibodies always detected in the first month following B-cell recovery. An incomplete CD19+CD20- B-cell depletion at M1 (5-25/mm³) and low serum rituximab levels was predictive of developing ARA. The development of de novo ARA during follow-up was not associated with shorter B-cell depletion.

CONCLUSIONS

This study shows that ARA are frequent in children with FR/SDNS and that close immuno- and pharmacological monitoring may help personalizing rituximab treatment in patients needing repeated injections.

Rituximab in children with steroid sensitive nephrotic syndrome: in quest of the optimal regimen

Rituximab has emerged as an effective and important therapy in children with complicated frequently relapsing and steroid-dependent nephrotic syndrome to induce long-term disease remission and avoid steroid toxicities. The optimal rituximab regimen is not totally well defined, and there are many varying practices worldwide. We will in this review describe how patient factors, rituximab dose, and use of maintenance immunosuppression affect treatment outcomes. Specifically, low-dose rituximab without concomitant immunosuppression is associated with shorter relapse-free duration while other regimens have comparable outcomes. Patients with more severe disease generally have worse response to rituximab. Although rituximab appears to be generally safe, there are growing concerns of chronic hypogammaglobulinemia and impaired immunity especially in young children. Reliable prognostications and biomarkers for guiding subsequent treatments to avoid excessive treatments are yet to be identified. In this review, we will outline the, as we see it, best approach of rituximab in childhood steroid sensitive nephrotic syndrome at the present state of knowledge.

Disseminated bartonellosis in a child with steroid-dependent nephrotic syndrome receiving mycophenolate mofetil monotherapy

Cat scratch disease, usually a benign infectious disease, may develop as multisystem disease with multiorgan involvement, particularly in immunocompromised patients. We report on a patient who developed disseminated bartonellosis while receiving mycophenolate mofetil monotherapy treating steroid-dependent nephrotic syndrome, highlighting that severe infection can be observed in those patients. Therefore, this category of patients should be cautious when having contact with kittens and receives proper prevention advice.

A global antiB cell strategy combining obinutuzumab and daratumumab in severe pediatric nephrotic syndrome

BACKGROUND

Steroid-sensitive nephrotic syndrome (SSNS) is, in most patients, a chronic disease with 80% experiencing at least one relapse after first flare. B cell depletion using rituximab is effective in preventing relapse in steroid-dependent (SDNS) patients but fails to maintain long-term remission following B cell recovery, possibly due to development of autoreactive long-lived plasma cells. We investigated sequential combination of antiCD20 antibody targeting all B cell subsets, and antiCD38 antibody with high plasma cell cytotoxicity in patients with uncontrolled SDNS after failure of one or several attempts at B cell depletion.

METHODS

Fourteen patients with median disease duration 7.8 years received 1000 mg/1.73 m² obinutuzumab followed by 1000 mg/1.73 m² daratumumab 2 weeks later. Oral immunosuppression was discontinued within 6 weeks, and biological monitoring performed monthly until B cell recovery.

RESULTS

Median age at treatment was 11.0 [IQR 10.4-14.4] years. B cell depletion was achieved in all patients, and B cell reconstitution occurred in all at median 9.5 months after obinutuzumab injection. After median follow-up 20.3 months (IQR 11.5-22.6), 5/14 patients relapsed including 4 within 100 days following B cell repletion. Relapse-free survival was 60% at 24 months from obinutuzumab infusion. Mild infusion reactions were reported in 3/14 patients during obinutuzumab and 4/14 during daratumumab infusions. Mild transient neutropenia (500-1000/mm³) occurred in 2/14 patients. Intravenous immunoglobulins were given to 12/14 patients due to hypogammaglobulinemia. Low IgA and IgM levels were noted in 8 and 14 patients, respectively. No severe infection was reported.

CONCLUSION

Global antiB cell strategy combining obinutuzumab and daratumumab induces prolonged peripheral B cell depletion and remission in children with difficult-to-treat SDNS.

Pediatric idiopathic steroid-sensitive nephrotic syndrome: diagnosis and therapy -short version of the updated German best practice guideline (S2e) - AWMF register no. 166-001, 6/2020

Idiopathic nephrotic syndrome is the most frequent glomerular disease in children in most parts of the world. Children with steroid-sensitive nephrotic syndrome (SSNS) generally have a good prognosis regarding the maintenance of normal kidney function even in the case of frequent relapses. The course of SSNS is often complicated by a high rate of relapses and the associated side effects of repeated glucocorticoid (steroid) therapy. The following recommendations for the treatment of SSNS are based on the comprehensive consideration of published evidence by a working group of the German Society for Pediatric Nephrology (GPN) based on the systematic Cochrane reviews on SSNS and the guidelines of the KDIGO working group (Kidney Disease - Improving Global Outcomes).

Unfavorable impact of anti-rituximab antibodies on clinical outcomes in children with complicated steroid-dependent nephrotic syndrome

BACKGROUND

Anti-rituximab antibodies (ARA) are associated not only with adverse events, such as infusion reactions (IR) and serum sickness, but also with rituximab efficacy. However, the clinical relevance of ARA in children with steroid-dependent nephrotic syndrome (SDNS) remains unknown.

METHODS

We retrospectively reviewed clinical outcomes of 13 children with complicated SDNS receiving repeated single-dose rituximab treatments at 375 mg/m² to assess whether ARA formation could impact toxicity and efficacy of additional rituximab. Pre-rituximab 22 samples collected from patients who developed IR during the second or subsequent rituximab doses were measured by electrochemiluminescence analysis.

RESULTS

ARA were identified in 5 of 13 patients (9 of 22 samples). Median time to recovery of CD19⁺ B cells to > 1% of total lymphocytes and median relapse-free time after rituximab treatment were significantly shorter in the 9 ARA-positive samples than the 13 ARA-negative samples (41 vs. 100 days, p < 0.01 and 119 vs. 308 days, p < 0.05, respectively). Kaplan-Meier analysis showed that time to CD19+ B cell recovery after rituximab was significantly shorter in ARA-positive samples than in ARA-negative samples (p < 0.005). Severe IR developed in two ARA-positive patients and serum sickness in one ARA-positive patient.

CONCLUSIONS

The incidence of ARA formation was high in the pre-rituximab samples of patients with complicated SDNS who developed IR during the second or subsequent rituximab doses, suggesting that ARA formation might have an unfavorable impact on the toxicity and efficacy of additional rituximab doses in these patients.

Rituximab for very low dose steroid-dependent nephrotic syndrome in children: a randomized controlled study

BACKGROUND

Steroid-dependent nephrotic syndrome (SDNS) carries a high risk of toxicity from steroids or steroid-sparing agents. This open-label, randomized controlled trial was designed to test whether the monoclonal antibody rituximab is non-inferior to steroids in maintaining remission in juvenile forms of SDNS and how long remission may last (EudraCT:2008-004486-26).

METHODS

We enrolled 30 children 4-15 years who had developed SDNS 6-12 months before and were maintained in remission with low prednisone doses (0.1-0.4 mg/Kg/day). Participants were randomized following a non-inferiority design to continue prednisone alone (n 15, controls) or to add a single intravenous infusion of rituximab (375 mg/m², n 15 intervention). Prednisone was tapered in both arms after 1 month. Children assigned to the control arm were allowed to receive rituximab to treat disease relapse.

RESULTS

Proteinuria increased at 3 months in the prednisone group (from 0.14 to 1.5 g/day) (p < 0.001) and remained unchanged in the rituximab group (0.14 g/day). Fourteen children in the control arm relapsed within 6 months. Thirteen children assigned to rituximab (87%) were still in remission at 1 year and 8 (53%) at 4 years. Responses were similar in children of the control group who received rituximab to treat disease relapse. We did not record significant adverse events.

CONCLUSIONS

Rituximab was non-inferior to steroids for the treatment of juvenile SDNS. One in two children remains in remission at 4 years following a single infusion of rituximab, without significant adverse events. Further studies are needed to clarify the superiority of rituximab over low-dose corticosteroid as a treatment of SDNS.

Long-term outcome of Japanese children with complicated minimal change nephrotic syndrome treated with mycophenolate mofetil after cyclosporine

BACKGROUND

Although recent studies have shown that more than half of children with steroid-dependent nephrotic syndrome (SDNS) may continue to have active disease beyond childhood, the long-term outcome in this cohort treated with mycophenolate mofetil (MMF) after cyclosporine remains unknown, particularly in adulthood.

METHODS

We conducted a retrospective study of 44 adult patients (median age, 22.3 years) who received MMF for complicated SDNS (median age at MMF initiation, 13.3 years) at a single center. Complicated SDNS was defined as the case continuing to relapse after cyclosporine (CsA) treatment. When patients experienced relapses despite MMF initiation, they additionally received a rituximab infusion. The primary endpoint was the probability of achieving treatment-free remission for > 2 years.

RESULTS

Prior to MMF initiation, all patients received CsA for a median of 46 months and 19 received the 12-week cyclophosphamide. After switching from CsA to MMF, only four patients did not relapse during a median follow-up period of 9.6 years. At the last visit, only 15 of the 44 patients achieved treatment-free sustained remission. Multivariate analysis revealed that young age (< 6 years) at onset of nephrotic syndrome (odds ratio, 11.3) and the experience of steroid dependency during initial CsA treatment (odds ratio, 29.8) were the independent risk factors of active disease into adulthood after MMF initiation.

CONCLUSIONS

Although none developed renal insufficiency and severe adverse effects of therapy, the introduction of MMF after CsA treatment may not be necessarily associated with improved long-term outcome of children with complicated SDNS.

Assessment of factors associated with mizoribine responsiveness in children with steroid-dependent nephrotic syndrome

BACKGROUND

Several immunosuppressants have been used to treat children with steroid-dependent nephrotic syndrome (SDNS). Mizoribine (MZR) is an immunosuppressant used to maintain remission in children with SDNS, although its effectiveness for treating SDNS remains controversial. Therefore, in this study, we assessed the clinical factors associated with children having SDNS who were successfully treated with MZR.

METHODS

A total of 47 children with SDNS who underwent MZR treatment were retrospectively evaluated. Clinical features including pharmacokinetics after MZR administration were compared between MZR responders and non-responders.

RESULTS

The comparison of the two groups revealed no significant differences in age, body weight (BW), daily dose of MZR per BW, serum concentration 2 h after administration (C₂), peak serum concentration (C_max), and area under the concentration curve 0-4 h after administration (AUC_0-4). C₂/(single dose/BW), C_max/(single dose/BW), and AUC_0-4/(single dose/BW) were significantly higher in the MZR responders than in the non-responders (all p < 0.01). Receiver operating characteristic analysis revealed that the cutoff values of C₂ (single dose/kg), C_max/(single dose/BW), and AUC_0-4/(single dose/BW) were 0.55, 0.58, and 1.37, respectively.

CONCLUSIONS

MZR is a useful immunosuppressant for treating frequent-relapse NS in children who are susceptible to the drug. The efficacy of MZR may be associated with not only serum concentrations defined by the dosage or absorption efficiency through MZR transporters, but also the susceptibility defined by the expression level and performance of MZR transporters on the target cells.

Efficacy of Semiannual Single Fixed Low-Dose Rituximab Therapy in Steroid-Dependent Minimal Change Nephrotic Syndrome: A Case Series

The frequency of using rituximab to treat refractory nephrotic syndrome has recently been increasing, and the conventional dose of rituximab used to treat it, 375 mg/m² body surface area once weekly for 4 weeks, has been modelled on the chemotherapy regimen for B-cell non-Hodgkin's lymphoma. The dose and intervals of rituximab in refractory nephrotic syndrome remain controversial. Clear lymphoma cell hyperplasia is seen in lymphoma patients, but not in nephrotic syndrome patients. Since we thought that it might be possible to reduce the dose of rituximab if only used for the purpose of depleting CD20-positive B cells in nephrotic patients' peripheral blood, we tried semiannually with a single fixed rituximab dose of 100 mg/body, and a complete remission was attained in 3 cases without treatment with prednisolone or cyclosporine. Our report strongly suggests considering appropriate dose and interval of rituximab therapy in the treatment of steroid-dependent nephrotic syndrome.

Therapeutic efficacy of rituximab for the management of adult-onset steroid-dependent nephrotic syndrome: a retrospective study

BACKGROUND

Recent reports have described the efficacy of rituximab in treating steroid-dependent nephrotic syndrome (SDNS) in pediatric patients. However, few reports describe data regarding adult-onset SDNS. We investigated the efficacy of rituximab for the management of adult-onset SDNS.

METHODS

We performed a retrospective cohort study investigating eight patients with adult-onset SDNS who were treated with rituximab. Clinical data were obtained at the initiation of rituximab therapy. The primary outcomes evaluated were successful suppression of relapses and CD19+ cells after rituximab treatment. The corticosteroid- and immunosuppressant-sparing effect and adverse events were additionally evaluated.

RESULTS

All eight patients were diagnosed with minimal change nephrotic syndrome and received immunosuppressants in addition to corticosteroid. Total number of relapses was 10.5 times as a median value. Rituximab administration was repeated in two patients, whereas six received single-dose rituximab. Three of eight (37.5%) patients showed relapse after rituximab therapy. A rituximab-induced depletion in CD19+ cells noted initially was followed by their reappearance in all patients. There were cases with no relapse after the reappearance of CD19+ cells. The median relapse time pre- and post-rituximab therapy showed a decrease from 1 time/year (interquartile range [IQR] 1-3 times/year) to 0 time/year (IQR 0-1 time/year). Rituximab treatment induced a significant reduction in the required doses of corticosteroid and cyclosporine (P < 0.01). No serious adverse events were observed.

CONCLUSION

Rituximab treatment was effective not only in childhood-onset but also in adult-onset SDNS. Further studies are needed to establish optimal treatment regimens.

Cost analysis on the use of rituximab and calcineurin inhibitors in children and adolescents with steroid-dependent nephrotic syndrome

BACKGROUND

Rituximab (RTX) is increasingly being used in place of calcineurin inhibitors (CNI) in pediatric patients with steroid-dependent nephrotic syndrome (SDNS). However, despite its favorable safety profile, its unit cost is prohibitive. We therefore compared the healthcare costs associated with the use of both agents in a retrospective cohort.

METHODS

This study was a retrospective analysis of data retrieved from the medical charts and electronic databases of pediatric patients (age range 2-18 years) with SDNS who were treated with either CNI or RTX from January 2008 to December 2012 at Children's Hospital of New Orleans, Louisiana. The minimum follow-up period was 12 months.

RESULTS

Of the 18 patients whose medical data were analyzed, ten received RTX and eight were treated with CNI. The annualized healthcare cost for the rituximab group was $197,031 versus $189,857 (all values in US dollars) for the CNI group (p > 0.05). At the 12-month follow-up, more patients in the RTX group were in remission (40 vs. 25%). Duration of freedom from steroid use was longer in the RTX group, while body mass index was higher in the CNI arm (p > 0.05). No significant adverse events occurred in either group.

CONCLUSION

The expenditure for the RTX and CNI groups was comparable, but there were fewer clinical encounters in the former group, potentially reducing the burden of healthcare on the patient's family.

Serum sickness with refractory nephrotic syndrome following treatment with rituximab

Rituximab (RTX) is effective for treating childhood refractory nephrotic syndrome (NS), such as steroid-dependent (SD), frequently relapsing (FR), and steroid-resistant (SR) NS. While RTX has been proven to be effective in treating SDNS, FRNS, and SRNS, it may cause serum sickness, a rare illness characterized by fever, rash, and arthralgia, 10-14 days after primary antigen exposure or within a few days after secondary antigen exposure, by producing human anti-chimeric antibodies (HACAs). A 17-year-old girl with refractory SDNS treated with RTX and oral cyclosporine A was admitted with fever and arthralgia 10 days after the fifth RTX dose was administered. After RTX was started when she was 14-years-old, SDNS remission was then achieved, and prednisolone was discontinued. Although antibiotics and non-steroidal anti-inflammatory agents were administered, fever and arthralgia continued. After various inspections and clinical course, we considered her as RTX-induced serum sickness (RISS). The patient had an elevated HACA level and was diagnosed with RISS. Fever and arthralgia disappeared 5 days after onset. To the best of our knowledge, this is the first reported case of RISS with NS. Fever, rash, and arthralgia after RTX administration can be the initial symptoms.

Rituximab in steroid-sensitive nephrotic syndrome: lessons from clinical trials

Idiopathic nephrotic syndrome is the most common chronic glomerular disease in children. A total of 80-90% of patients with childhood idiopathic nephrotic syndrome achieve remission with steroid therapy [steroid-sensitive nephrotic syndrome (SSNS)]. However, approximately 50% of children with SSNS develop frequently relapsing nephrotic syndrome (FRNS) or steroid-dependent nephrotic syndrome (SDNS). Children with FRNS or SDNS are usually treated with immunosuppressive agents, but 10-20% of children receiving immunosuppressive agents still show frequent relapses or steroid dependence during or after treatment, defined as complicated FRNS or SDNS. Rituximab, a chimeric anti-CD20 monoclonal antibody that was originally developed to treat patients with B-cell non-Hodgkin's lymphoma, is currently used for treating SSNS. In this review we highlight recent studies, mainly randomized controlled trials of rituximab for SSNS, including complicated and uncomplicated forms of FRNS or SDNS in children. We also discuss the effects of these studies on the management of patients suffering from these conditions.

Long-term outcome of childhood-onset complicated nephrotic syndrome after a multicenter, double-blind, randomized, placebo-controlled trial of rituximab

BACKGROUND

Although rituximab effectively prevents relapses of complicated frequently relapsing nephrotic syndrome (FRNS) and steroid-dependent nephrotic syndrome (SDNS), data of long-term outcomes and safety are limited.

METHODS

Fifty-one patients (age, 3-38 years) with childhood-onset complicated FRNS or SDNS, who received rituximab in investigator-initiated multicenter prospective trials were enrolled. Rituximab was administered at 375 mg/m² once weekly for 4 weeks, and immunosuppressive agents were discontinued according to the study protocol. We investigated relapses, re-administration of immunosuppressive agents, additional rituximab treatment, body height, renal function, and late adverse events during the observation period.

RESULTS

Forty-eight patients (94%) developed relapses during the observation period (median, 59 months) and the 50% relapse-free survival was 261 days. Thirty patients (59%) developed SDNS, 44 (86%) required re-administration of immunosuppressive agents, and 22 (43%) received additional rituximab treatment. All patients who were receiving immunosuppressive agents at rituximab treatment required either immunosuppressive agents or additional rituximab treatment. On the contrary, 5 of the 13 patients without immunosuppressive agents at rituximab treatment required neither immunosuppressive agents nor additional rituximab treatment and 3 of them did not develop relapse during observation period. Growth failure due to steroid toxicity did not progress and none of the patients developed chronic renal insufficiency. None of the patients suffered from rituximab-related late adverse events.

CONCLUSIONS

As most patients suffer from relapses after B-cell recovery, long-term immunosuppressive agents or additional rituximab treatment is necessary. However, some patients who can discontinue immunosuppressive agents before rituximab treatment may achieve long-term remission after rituximab treatment without immunosuppressive agents.

Effectiveness and nephrotoxicity of a 2-year medium dose of cyclosporine in pediatric patients with steroid-dependent nephrotic syndrome: determination of the need for follow-up kidney biopsy

BACKGROUND

High dose of cyclosporine (CyA) for ≥2 years in children with steroid-dependent nephrotic syndrome (SDNS) increases the risk for nephropathy. Considering this, risk can be lowered with lower doses of CyA; we evaluated the effects of a medium dose of CyA, with target serum level, C2, of 450 ng/ml, over a 2-year period of observation, to determine the need for follow-up kidney biopsy.

METHODS

We retrospectively evaluated C2 levels in 38 patients (17 males, 5.2 ± 2.9 years old) with SDNS at treatment initiation, at 6, 12 and 18 months during treatment, and at the time of kidney biopsy, 2-year after treatment initiation. Fifteen patients were also treated with mizoribine or mycophenolate mofetil. A number of relapses-per-patient-per-year, relative to SDNS onset and initiation of CyA treatment, were evaluated. Serum levels of total protein, albumin and total cholesterol, blood urea nitrogen level, and the estimated glomerular filtration rate were measured at treatment initiation and at 1- and 2-year post-treatment initiation.

RESULTS

Only one very mild case of CyA-associated nephrotoxicity was identified based on biopsy results at 2-year post-treatment initiation. C2 concentrations were maintained at 422.2 ± 133.5 ng/ml and the number of relapses decreased from 3.0 relapses-per-patient-per-year prior to CyA treatment to 0.47 relapses-per-patient-per-year after CyA treatment. No effects of the treatment on the estimated glomerular filtration rate were noted.

CONCLUSION

A 2-year treatment with a medium dose of cyclosporine A with or without other immunosuppressive agents is relatively safe with regard to the development of cyclosporine A nephrotoxicity.

Rituximab in children with steroid-dependent nephrotic syndrome: experience of a tertiary center and review of the literature

OBJECTIVES

Rituximab (RTX) is a new treatment option in children with difficult-to-treat steroid-dependent nephrotic syndrome (SDNS). We evaluated the experience of our tertiary center and reviewed the current literature.

METHODS

This is a retrospective single-center study evaluating the efficacy and safety of RTX in children with difficult-to-treat SDNS. Age at diagnosis, type and duration of immunosuppression, age at administration, dose of RTX, possible adverse events, number of relapses, duration of remission, and B-cell count after administration of RTX were analyzed.

RESULTS

Nine children with a median age at diagnosis of nephrotic syndrome of 4.75 (range 1.33-11.33) years and a median age at administration of RTX of 16.08 (range 3.33-19.25) years were included. Before administration of RTX they had a median number of relapses per year of 1.70 (range 0.82-4.80). At last follow-up (median 2.75 years, range 0.58-3.92), a reduction in the number of relapses per year to 0.26 (range 0-2.18) was noted, despite cessation or lowering the dose of immunosuppressive therapy. Four patients achieved complete remission after the first administration of RTX, four more patients after subsequent doses of RTX. No severe adverse events were noted.

CONCLUSION

RTX was an effective and safe therapeutic option in our cohort of children with difficult-to-treat SDNS, resulting in a significant reduction of yearly relapses in the absence of severe adverse events and facilitating the reduction of other immunosuppressive medication.

Ofatumumab in two pediatric nephrotic syndrome patients allergic to rituximab

BACKGROUND

Rituximab, a chimeric anti-CD20 monoclonal antibody, is an effective treatment in steroid-dependent nephrotic syndrome (SDNS). However, some patients develop adverse reactions.

CASE-DIAGNOSIS/TREATMENT

Patient 1, a 14-year-old boy with SDNS since the age of 2, was treated with oral prednisone, cyclosporine A (CsA) and mycophenolate mofetil. A first infusion of rituximab at age 12 years was well tolerated, but this was followed by a prolonged relapse unresponsive to oral prednisone, mycophenolate mofetil and CsA. A second rituximab infusion was attempted, but treatment was interrupted due to severe dyspnea. Treatment with a humanized anti-CD20 monoclonal antibody, ofatumumab, was then attempted. The patient experienced a mild allergic reaction and maintained remission despite interruption of all treatment at >12 months of follow-up. Patient 2, a 3-year-old boy who presented at 18 months with nephrotic syndrome initially resistant to treatment with oral prednisone, was given with three intravenous boluses of methylprednisolone followed by CsA and achieved remission. Upon steroid discontinuation, the NS relapsed. Prednisone was restarted and treatment with a single dose of rituximab was never completed due to a severe allergic reaction. Ofatumumab infusion was uneventful, and he maintained remission during the follow-up period (>12 months) despite interruption of prednisone therapy. B cells reappeared at 7 months in both patients.

CONCLUSIONS

Ofatumumab may be a therapeutic option in severe forms of NS with allergy to rituximab.

Montelukast as an add-on treatment in steroid dependant nephrotic syndrome, randomised-controlled trial

BACKGROUND

The underlying mechanisms of nephrotic syndrome (NS) are still under debate and the need for more effective and less toxic treatment is challenging. We aimed to evaluate the efficacy of montelukast, a leukotriene receptor antagonist as an add-on therapy, and to explore the leukotriene (LT) biology in steroid-dependent nephrotic syndrome (SDNS).

METHODS

A randomized controlled trial was conducted including 32 patients with SDNS who were randomly assigned to receive standard steroid treatment only [low-dose steroid (LDS) group] or standard steroid therapy plus montelukast (Montelukast group). Urine protein/creatinine ratio, serum albumin, creatinine, cholesterol, and plasma LTs (LTB4/C4/D4/E4) were evaluated in all patients before and after treatment.

RESULTS

After treatment, both groups showed a significant decrease of LTB4 and LTC4/D4/E4. Further, the Montelukast group showed a significant decrease in serum creatinine and a significant increase in diastolic blood pressure and protein/creatinine ratio. It also showed a marked decrease in plasma LTC4/D4/E4 compared to the LDS group, although not statistically significant.

CONCLUSIONS

Our findings highlight the effect of montelukast on renal function, but suggest that the clinical and laboratory efficacy of the addition of montelukast to steroids in maintenance treatment of SDNS is debatable.

Risk factors for relapse and long-term outcome in steroid-dependent nephrotic syndrome treated with rituximab

BACKGROUND

Rituximab (RTX) is known to be effective for the treatment of refractory steroid-dependent nephrotic syndrome (SDNS). However, there are insufficient data on the risk factors for relapse and long-term outcome after RTX treatment.

METHODS

We administered a single dose of RTX to patients with refractory SDNS from November 2007 to December 2013 and continued with immunosuppressants. The risk factors for early relapse and long-term outcome were analyzed.

RESULTS

Eighty-one patients were included and the observation period was 13-90 months. Seventy-six patients (94 %) discontinued steroids. Median duration of B-cell depletion was 160 days and 50 % relapse-free survival was 482 days. In multivariate analyses, only a history of steroid-resistant nephrotic syndrome (SRNS) was a statistically significant risk factor (hazard ratio, 2.44; p = 0.048). Fifty percent relapse-free survival in patients without a history of SRNS was 615 days, longer than that of patients with a history of SRNS (393 days) (p=0.005) [corrected]. Fifty-one patients (63 %) received additional RTX treatments for relapses. At last observation, patients using calcineurin inhibitors decreased from 89 % to 23 %, and 12 patients (15 %) discontinued immunosuppressants.

CONCLUSIONS

Rituximab treatment followed by immunosuppressants is an effective option for patients with SDNS, although a history of SRNS is a risk factor for early relapse.

Second-line immunosuppressive treatment of childhood nephrotic syndrome: a single-center experience

Objective

Most cases of idiopathic nephrotic syndrome in childhood are responsive to corticosteroids. However, there is a small group of children that demonstrate steroid resistance (steroid-resistant nephrotic syndrome; SRNS), steroid dependence, or that frequently relapse (frequent-relapse steroid-sensitive nephrotic syndrome; FR-SSNS) which are more clinically difficult to treat. Therefore, second-line immunosuppressants, such as alkylating agents, calcineurin inhibitors, antimetabolites and, more recently, rituximab, have been used with varying success. The objective was to evaluate the response rates of various second-line therapies in the treatment of childhood nephrotic syndrome.

Study Design

A retrospective chart review of pediatric subjects with idiopathic nephrotic syndrome was conducted at a single tertiary care center (2007-2012). Drug responses were classified as complete response, partial response, and no response.

Results

Of the 188 charts reviewed, 121 children were classified as SSNS and 67 children as SRNS; 58% were classified as FR-SSNS. Sixty-five subjects were diagnosed with focal segmental glomerulosclerosis via biopsy. Follow-up ranged from 6 months to 21 years. The combined rate of complete and partial response for mycophenolate mofetil (MMF) was 65% (33/51) in SSNS and 67% (6/9) in SRNS. For tacrolimus, the response rate was 96% (22/23) for SSNS and 77% (17/22) for SRNS. Eighty-three percent (5/6) of SSNS subjects treated with rituximab went into complete remission; 60% relapsed after B-cell repletion. Eight refractory subjects were treated with combined MMF/tacrolimus/corticosteroid therapy with a 75% response rate.

Conclusion

Our experience demonstrates that older medications can be replaced with newer ones such as MMF, tacrolimus, and rituximab with good outcomes and better side effect profiles. The treatment of refractory cases with combination therapy is promising.