Tacrolimus in steroid-resistant and steroid-dependent nephrotic syndrome

Biologics in steroid resistant nephrotic syndrome in childhood: review and new hypothesis-driven treatment

Nephrotic syndrome affects about 2-7 per 100,000 children yearly and accounts for less than 15% of end stage kidney disease. Steroids still represent the cornerstone of therapy achieving remission in 75-90% of the cases The remaining part result as steroid resistant nephrotic syndrome, characterized by the elevated risk of developing end stage kidney disease and frequently presenting disease recurrence in case of kidney transplant. The pathogenesis of nephrotic syndrome is still far to be elucidated, however, efficacy of immune treatments provided the basis to suggest the involvement of the immune system in the pathogenesis of the disease. Based on these substrates, more immune drugs, further than steroids, were administered in steroid resistant nephrotic syndrome, such as antiproliferative and alkylating agents or calcineurin inhibitors. However, such treatments failed in inducing a sustained remission. In last two decades, the developments of monoclonal antibodies, including the anti-CD20 rituximab and inhibitor of B7-1 abatacept, represented a valid opportunity of treatment. However, also the effectiveness of biologics resulted limited. We here propose a new hypothesis-driven treatment based on the combining administration of rituximab with the anti-CD38 monoclonal antibody daratumumab (NCT05704400), sustained by the hypothesis to target the entire B-cells subtypes pool, including the long-lived plasmacells.

Role of cyclosporin A in the treatment of kidney disease and nephrotoxicity

The clinical use of cyclosporin A (CsA) has led to significant advances and achievements in the field of transplantation and immune diseases. However, the nephrotoxicity of CsA is a major concern in current immunosuppression regimens. CsA causes abnormal kidney function while treating kidney disease, causing problems for clinicians and patients. Evidence of CsA nephrotoxicity is almost always present in transplant recipients after long-term CsA administration (up to 10 years), and similar phenomena occur with other calcineurin inhibitors. In this review, we summarize the mechanisms and influencing factors of CsA for the treatment of primary nephrotic syndrome. The mechanisms of CsA nephrotoxicity, clinical-pathological features, diagnosis, prevention strategies, and risk factors are summarized. We discuss the correlates and mechanisms of the switch between kidney disease prevention and nephrotoxicity of CsA to better understand the function of CsA in the kidney and to provide a basis for the prevention and treatment of CsA nephrotoxicity.

Tacrolimus in the treatment of childhood nephrotic syndrome: Machine learning detects novel biomarkers and predicts efficacy

STUDY OBJECTIVE

The pharmacokinetics and pharmacodynamics of tacrolimus (TAC) vary greatly among individuals, hindering its precise utilization. Moreover, effective models for the early prediction of TAC efficacy in patients with nephrotic syndrome (NS) are lacking. We aimed to identify key factors affecting TAC efficacy and develop efficacy prediction models for childhood NS using machine learning algorithms.

DESIGN

This was an observational cohort study of patients with pediatric refractory NS.

SETTING

Guangzhou Women and Children's Medical Center between June 2013 and December 2018.

PATIENTS

203 patients with pediatric refractory NS were used for model generation and 35 patients were used for model validation.

INTERVENTION

All patients regularly received double immunosuppressive therapy comprising TAC and low-dose prednisone or methylprednisolone. In this observational cohort study of 203 pediatric patients with refractory NS, clinical and genetic variables, including single-nucleotide polymorphism (SNPs), were identified. TAC efficacy was evaluated 3 months after administration according to two different evaluation criteria: response or non-response (Group 1) and complete remission, partial remission, or non-remission (Group 2).

MEASUREMENTS

Logistic regression, extremely random trees, gradient boosting decision trees, random forest, and extreme gradient boosting algorithms were used to develop and validate the models. Prediction models were validated among a cohort of 35 patients with NS.

MAIN RESULTS

The random forest models performed best in both groups, and the area under the receiver operating characteristics curve of these two models was 80.7% (Group 1) and 80.3% (Group 2). These prediction models included urine erythrocyte count before administration, steroid types, and eight SNPs (ITGB4 rs2290460, TRPC6 rs3824934, CTGF rs9399005, IL13 rs20541, NFKBIA rs8904, NFKBIA rs8016947, MAP3K11 rs7946115, and SMARCAL1 rs11886806).

CONCLUSIONS

Two pre-administration models with good predictive performance for TAC response of patients with NS were developed and validated using machine learning algorithms. These accurate models could assist clinicians in predicting TAC efficacy in pediatric patients with NS before utilization to avoid treatment failure or adverse effects.

Efficacy and steroid-sparing effect of tacrolimus in patients with autoimmune cytopenia

The aim of this study was to evaluate the efficacy, safety, and steroid-sparing effect of tacrolimus in patients with autoimmune cytopenia, including immune thrombocytopenia (ITP), autoimmune hemolytic anemia (AIHA), and Evans syndrome (ES). Patients in the tacrolimus group were treated with tacrolimus in combination with steroids, and the control group received only steroids. Of the 318 patients finally enrolled, 87 (27.4%) were males, with a median age of 45 (14-90) years. The tacrolimus group comprised 144 patients, including 120 ITP, 19 AIHA, and 5 ES patients, and the control group comprised 174 patients, including 141 ITP, 25 AIHA, and 8 ES patients. The optimal ORR of the tacrolimus group was comparable to that of the control group, and the optimal CRR was higher (p < 0.05). Patients receiving tacrolimus had a decreased relapse rate and prolonged relapse-free survival (p < 0.05) compared with the controls for both the whole cohort and the ITP and AIHA subgroups. Compared with the control group, the tacrolimus group had a lower cumulative steroid dosage and earlier discontinuation of steroids (p < 0.05), which resulted in a decreased incidence of steroid-related adverse events (p < 0.05) although the total side effects were similar between the two groups. Similar drug expenses were observed between the tacrolimus and control groups at the 18-month follow-up. In conclusion, the early addition of tacrolimus had a similar ORR, better CRR, lower relapse rate, and prolonged relapse-free survival compared to steroids alone, with reduced steroid-related adverse events.

Efficacy and safety of tacrolimus versus corticosteroid as initial monotherapy in adult-onset minimal change disease: a meta-analysis

Objective

The objective of this meta-analysis was to compare the efficacy and safety of tacrolimus (TAC) monotherapy versus corticosteroid as initial monotherapy in adult-onset minimal change disease (MCD) patients.

Methods

Databases including PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure, and Wanfang database were searched from the inception to March 20, 2021. Eligible studies comparing TAC monotherapy and corticosteroid as initial monotherapy for adult-onset MCD patients were included. Data were analyzed using Review Manager Version 5.3.

Results

Four randomized controlled trials (RCTs) involving 196 patients were included in the meta-analysis. For initial monotherapy for adult-onset MCD, TAC and corticosteroid had similar complete remission (OR 1.06, 95% CI 0.47–2.41, P = 0.89), total remission (OR 1.30, 95% CI 0.39–4.35, P = 0.67), relapse rate (OR 0.63, 95% CI 0.28–1.42, P = 0.26). Main drug-related adverse effects of two therapeutic regimens had no difference concerning infection (OR 0.54, 95% CI 0.23–1.27, P = 0.15), glucose intolerance (OR 0.55, 95% CI 0.16–1.84, P = 0.33) and acute renal failure (OR 1.37, 95% CI 0.36–7.31, P = 0.71).

Conclusion

TAC monotherapy is comparable with corticosteroid monotherapy in initial therapy of MCD. To further confirm the conclusion, more large multicenter RCTs are necessary.

Clinical efficacy and safety of different tacrolimus concentrations for the treatment of patients with idiopathic membranous nephropathy

This retrospective study aimed to explore the relative efficacy and safety of different tacrolimus (TAC) concentrations in the treatment of patients with idiopathic membranous nephropathy (IMN). A total of 260 IMN patients with nephrotic syndrome (NS) were recruited. Among these, 125 patients had TAC concentrations no greater than 5 ng/ml (C_TAC ≤ 5 ng/ml), and 135 patients had TAC concentrations greater than 5 ng/ml (C_TAC > 5 ng/ml). The primary outcomes included complete remission (CR) rates and overall (OR) response rates. The secondary outcomes included 24-h urinary protein (24-h UP), serum albumin and serum creatinine, and adverse events (AEs). During the 12-month follow-up, the overall response rates were significantly different between the C_TAC ≤ 5 ng/ml group and the C_TAC > 5 ng/ml group (P < 0.0001). However, there was no significant difference in the CR at 12 months between the two groups (chi-square, 62% vs 63%, P = 0.852). Compared with the C_TAC ≤ 5 ng/ml group, the C_TAC > 5 ng/ml group had improved levels of 24 h UP (P = 0.017) and serum albumin (P = 0.010). Moreover, the incidences of acute reversible nephrotoxicity (P < 0.001), hepatotoxicity (P = 0.036), new-onset diabetes mellitus (P = 0.036), and glucose intolerance (P = 0.005) were lower in the C_TAC ≤ 5 ng/ml group than in the C_TAC > 5 ng/ml group. The C_TAC > 5 ng/ml group was improved relative to the C_TAC ≤ 5 ng/ml group in terms of a PR and CR at 6 months, but there was no difference in the CR between the two groups at 12 months.

CD80 Insights as Therapeutic Target in the Current and Future Treatment Options of Frequent-Relapse Minimal Change Disease

Minimal change disease (MCD) is the most common cause of idiopathic nephrotic syndrome in children, and it is well known for its multifactorial causes which are the manifestation of the disease. Proteinuria is an early consequence of podocyte injury and a typical sign of kidney disease. Steroid-sensitive patients react well with glucocorticoids, but there is a high chance of multiple relapses. CD80, also known as B7-1, is generally expressed on antigen-presenting cells (APCs) in steroid-sensitive MCD patients. Various glomerular disease models associated with proteinuria demonstrated that the detection of CD80 with the increase of urinary CD80 was strongly associated closely with frequent-relapse MCD patients. The role of CD80 in MCD became controversial because one contradicts finding. This review covers the treatment alternatives for MCD with the insight of CD80 as a potential therapeutic target. The promising effectiveness of CD20 (rituximab) antibody and CD80 inhibitor (abatacept) encourages further investigation of CD80 as a therapeutic target in frequent-relapse MCD patients. Therapeutic-based antibody towards CD80 (galiximab) had never been investigated in MCD or any kidney-related disease; hence, the role of CD80 is still undetermined. A new therapeutic approach towards MCD is essential to provide broader effective treatment options besides the general immunosuppressive agents with gruesome adverse effects.

Impact of CYP3A4/5 and ABCB1 polymorphisms on tacrolimus exposure and response in pediatric primary nephrotic syndrome

Aim: To evaluate the impact of CYP3A4*1G, CYP3A5*3 and ABCB1-C3435T polymorphisms on tacrolimus concentrations, efficacy and tolerance in pediatric primary nephrotic syndrome. Methods: Dose-adjusted concentrations (C₀/D), daily dose, frequency and time to relapse, cumulative remission days, and adverse reactions in 65 Chinese patients with various genotypes were retrospectively collected and compared. Results: C₀/D increased in CYP3A4*1/*1, CYP3A5*3/*3 and CYP3A4*1/*1-3A5*3/*3 diplotype carriers by 38.4, 69.7 and 40.9% compared with CYP3A4*1/*1G, CYP3A5*1/*3 and noncarriers, respectively. Recurrence risks were decreased in CYP3A4*1/*1 (0.43 of hazard ratio to *1/*1G) and CYP3A5*3/*3 carriers (0.43 of hazard ratio to *1/*3). None of polymorphisms was linked to adverse reactions. Conclusion: The genotypes of CYP3A4*1G and CYP3A5*3 rather than ABCB1-C3435T potentially predicted tacrolimus exposure and clinical response in pediatric primary nephrotic syndrome.

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.

New biologics in the treatment of rare glomerular diseases of childhood

Minimal change disease and focal segmental glomerulosclerosis are rare but important causes of end-stage kidney disease in children. Though their pathogenesis is still unclear, evidence of immune abnormalities provided the background for the use of immunosuppressive drugs, such as corticosteroids, calcineurin inhibitors, antiproliferative and alkylating agents. Unfortunately, these treatments fail to achieve a sustained remission in a significant portion of patients and are burdened by significant toxicities. Recent developments of new biologics, including anti-CD20 monoclonal antibodies rituximab and ofatumumab, offered the opportunity to selectively target immune cell subsets or activation pathways, leading to more effective and safer hypothesis-driven treatments.

Pathophysiological mechanisms of calcineurin inhibitor-induced nephrotoxicity and arterial hypertension

Solid organ transplantation is an established treatment modality in patients with end-stage organ damage in cases where other therapeutic options fail. The long-term outcomes of solid organ transplant recipients have improved considerably since the introduction of the first calcineurin inhibitor (CNI) - cyclosporine. In 1984, the potent immunosuppressive properties of another CNI, tacrolimus, were discovered. The immunosuppressive effects of CNIs result from the inhibition of interleukin-2 synthesis and reduced proliferation of T cells due to calcineurin blockade. The considerable side effects that are associated with CNIs therapy include arterial hypertension and nephrotoxicity. The focus of this article was to review the available literature on the pathophysiological mechanisms of CNIs that induce chronic nephrotoxicity and arterial hypertension. CNIs lead to activation of the major vasoconstriction systems, such as the renin-angiotensin and endothelin systems, and increase sympathetic nerve activity. On the other hand, CNIs are known to inhibit NO synthesis and NO-mediated vasodilation and to increase free radical formation. Altogether, these processes cause endothelial dysfunction and contribute to the impairment of organ function. A better insight into the mechanisms underlying CNI nephrotoxicity could assist in developing more targeted therapies of arterial hypertension or preventing CNI nephrotoxicity in organ transplant recipients, including heart transplantation.

Evaluation of mycophenolate mofetil or tacrolimus in children with steroid sensitive but frequently relapsing or steroid-dependent nephrotic syndrome

AIM

Approximately 30-40% of children with steroid sensitive nephrotic syndrome have frequently relapsing nephrotic syndrome (FRNS) or steroid-dependent nephrotic syndrome (SDNS). Mycophenolate mofetil (MMF) and tacrolimus (TAC) are often alternative treatment choices for these patients.

METHODS

A single-center prospective study was conducted to compare the efficacy of MMF or TAC in reducing relapses and maintaining remission in children with FRNS or SDNS. Of the 72 recruited patients, either MMF (20∼30 mg/kg/d, n = 34) or TAC (0.05∼0.15 mg/kg/d, n = 38) was administered for 12 months.

RESULTS

The mean 6-month relapse rates decreased from 2.56 episodes before therapy to 0.76 episodes in the first 6 months after therapy (c(2) = 44.362, p < 0.001) and 0.67 in the next 6 months (c(2) = 37.817, p < 0.001) in the MMF group. In the TAC group, the mean 6-month relapse rates decreased from 2.39 episodes before therapy to 0.41 episodes in the first 6 months after therapy (c(2) = 62.242, p < 0.001) and 0.42 in next 6 months (c(2) = 67.482, p < 0.001). No significant difference in the relapse rate was found between the groups (before therapy, c(2) = 0.902, p = 0.637; first 6 months, c(2) = 5.358, p = 0.147; second 6 months, c(2) = 4.089, p = 0.252). And there was also no significant difference in cumulative sustained remission and the incidence of adverse events between two groups.

CONCLUSIONS

In combination with low-dose steroids, MMF or TAC presented similar efficacy in maintaining remission in children with FRNS/SDNS in the present study. Therapy with MMF or TAC is a promising strategy with a moderate risk of side effects in children who are steroid sensitive but have FRNS/SDNS.

Recurrent Primary Focal Segmental Glomerulosclerosis Managed With Intensified Plasma Exchange and Concomitant Monitoring of Soluble Urokinase-Type Plasminogen Activator Receptor-Mediated Podocyte β3-integrin Activation

BACKGROUND

Primary focal segmental glomerulosclerosis (FSGS) often causes nephrotic proteinuria and frequently results in end-stage renal disease and recurrence after kidney transplantation. Recent studies describe soluble urokinase-type plasminogen activator receptor (suPAR) as a circulating factor implicated in FSGS.

METHODS

This single-center study included 12 adult patients with histologically proven primary FSGS (n = 2) or recurrent FSGS after transplantation (n = 10). The effect of plasma exchange (PE) on clinical outcome, suPAR levels, and in vitro podocyte β3-integrin activation was investigated over a median of 11 (6-18) sessions of PE.

RESULTS

The course of treatment was monitored in a total of 70 sessions of PE, which partly eliminated suPAR, with a mean reduction of 37 ± 12% of serum concentration per session. However, a substantial rebound was observed between sessions, with suPAR levels reaching 99 ± 22% of the pretreatment levels after a median of 4 days. Podocyte β3-integrin activation dropped significantly after PE but rebounded within 4 days concomitant with a rising suPAR level. In 11 of 12 patients, multimodal treatment (including extensive PE) reduced proteinuria significantly (from 5.3 [2.0-7.8] to 1.0 [0.4-1.6] g/d), indicating clinical efficacy of the therapy. One patient suffered allograft loss due to FSGS recurrence. A persisting response was independent of a lasting reduction in the level of total suPAR because there was no sustained significant change in suPAR levels before and after the course of intensified treatment (3814 ± 908 to 3595 ± 521 pg/mL; P = 0.496).

CONCLUSIONS

We conclude that multimodal therapy including extensive PE was associated with stabilization of recurrent FSGS and a temporary lowering of plasma suPAR as well as podocyte β3-integrin activation. Whether a sustained lowering of total suPAR results in further improved outcomes requires additional study.

Tacrolimus for children with refractory nephrotic syndrome: a one-year prospective, multicenter, and open-label study of Tacrobell®, a generic formula

BACKGROUND

Cyclosporine A and tacrolimus (TAC) are often used as a second-line treatment for children with refractory nephrotic syndrome (NS). This study was undertaken to investigate the efficacy and safety of Tacrobell®, a locally produced generic form of TAC.

METHODS

This study was a one-year prospective, open-label, single-arm, multicenter trial. Fourty-four children with steroid-dependent NS (SDNS) and 33 children with steroid-resistant NS (SRNS) were enrolled. The primary endpoints were defined as the remission rates, whereas the secondary endpoints were recognized as the duration of remission and adverse effects of TAC.

RESULTS

After one-year treatment, 34 (77.3%) of the 44 patients with SDNS were in complete remission, and 6 (13.6%) were in partial remission. Nineteen (43.2%) patients did not relapse during the study; for those who did relapse, the mean duration of remission was 4.6±2.9 months. The number of relapse episodes during the study period (0.90 per patient-year) was significantly lower than that in the preceding year (2.8 per patient-year). After treatment for 3 and 6 months, 12 (36.4%) of the 33 patients with SRNS were in remission, and after treatment for 12 months, the number of patients had increased to 13 (39.4%). The mean time to achieve remission was 4.0±3.2 months. After remission (duration, 3.7±2.7 months), 12 (54.5%) of 22 patients relapsed. The fasting blood glucose and blood pressure levels during the therapy were similar to those at the time of study entry.

CONCLUSIONS

Treatment with Tacrobell® was effective and safe for children with refractory NS. The efficacy of this generic form of TAC was better than that of the original TAC formula.

Clinical efficacy and pharmacokinetics of tacrolimus in children with steroid-resistant nephrotic syndrome

BACKGROUND

Tacrolimus has gained acceptance in the management of steroid-resistant nephrotic syndrome (SRNS) in children. Due to limited data, therapeutic range is extrapolated from pediatric renal transplant recipients. This study was designed to assess therapeutic efficacy of tacrolimus in children with SRNS and its correlation with inter-dose area under concentration curve (AUC0-12 h) and trough concentration (C0).

METHODS

Pre dose, 0.5, 1.0, 1.5, 2.0, 2.5, 3, 4, 8, and 12 h after drug administration blood samples were collected in 25 children who were on tacrolimus for a minimum of 3 months and AUC0-12 h was calculated.

RESULTS

There was an 80% (20/25) response rate with 64% (16/25) children achieving complete remission. Median C0 in remission was higher than in relapse group (2.95 ng/ml, versus 1.20 ng/ml, p = 0.005). Median AUC0-12 h in remission was higher compared to those in relapse group (79.75 versus 35.15 μg × h/l; p = 0.025). Maximum concentration after drug administration (Cmax) among the groups was not significantly different. There was a significant correlation between C0 and AUC0-12 h (r = 0.79); and Cmax and AUC0-12 h (r = 0.84). Five patients had a rise in serum creatinine, of which four were still proteinuric and had lower C0 and AUC0-12 h. No other adverse effect was noted.

CONCLUSIONS

Tacrolimus had beneficial clinical response in SRNS. Target C0 and AUC0-12 h level for treatment remission was higher than those in relapse in children with SRNS but was lower than required in transplant recipient.

The treatment of idiopathic focal segmental glomerulosclerosis in adults

Focal segmental glomerulosclerosis (FSGS) is the histologic end point of many disease processes that affect the kidney. Clinically, adults with FSGS present with proteinuria that may be accompanied by the nephrotic syndrome. Once identifiable (secondary) causes are excluded, the diagnosis of idiopathic FSGS, a challenging glomerular disease to understand and manage, is made. On the basis of mostly retrospective data, first-line treatment for idiopathic FSGS patients with nephrotic-range proteinuria is a prolonged course of corticosteroids. However, steroid resistance is common and portends an increased risk of long-term decline in kidney function and end-stage kidney disease in these patients compared with responders. Multiple other immunosuppression regimens have been used in steroid-resistant FSGS, some of which have been studied in randomized controlled trials. Here, we review the data on the treatment for idiopathic FSGS in adults.

Rituximab treatment for relapsing minimal change disease and focal segmental glomerulosclerosis: a systematic review

BACKGROUND

Minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) remain a therapeutic challenge, since steroids and other immunosuppressive agents exhibit an unfavorable adverse event spectrum. The aim of this review was to systematically summarize and analyze data from preexisting studies reporting the outcome of rituximab (RTX) treatment in these patients.

METHODS

Study data on adult patients with either steroid-dependent or frequently relapsing MCD/FSGS were identified by a PubMed and Embase search. The number of relapses was calculated and the use of immunosuppressive co-medication prior to and after RTX treatment was quantified.

RESULTS

We identified 14 studies including 86 patients with frequently relapsing and steroid-dependent MCD or FSGS. Treatment with RTX reduced the number of relapses per year from 1.3 (0-9) relapses prior to treatment compared to 0 (0-2) after therapy (p < 0.001). Proteinuria decreased from 2.43 (0-15) g/day to 0 (0-4.89) g/day (p < 0.001), while serum albumin increased from 2.9 (1.2-4.6) at baseline to 4.0 (1.8-5.09) g/l after RTX (p = 0.001). The use of immunosuppression used at the time of RTX administration was also reduced after RTX therapy (p < 0.001). Baseline serum albumin was lower (p = 0.018), whereas the number of immunosuppressants prior to RTX was higher (p = 0.018) in patients with relapse after RTX.

CONCLUSIONS

The published data suggest that RTX is effective in reducing the number of relapses and sparing immunosuppression in frequently relapsing and steroid-dependent nephrotic syndrome due to MCD and FSGS. These promising findings have to be confirmed in controlled and prospective studies.

Treatment of idiopathic FSGS with adrenocorticotropic hormone gel

BACKGROUND AND OBJECTIVES

Adrenocorticotropic hormone (ACTH) has shown efficacy as primary and secondary therapy for nephrotic syndrome due to membranous nephropathy. The data on using ACTH to treat idiopathic FSGS are limited. This report describes our experience using ACTH for nephrotic syndrome due to idiopathic FSGS in the United States.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Twenty-four patients with nephrotic syndrome from idiopathic FSGS were treated with ACTH gel at two academic medical centers between 2009 and 2012, either as part of investigator-initiated pilot studies (n=16) or by prescription for treatment-resistant FSGS (n=8). The primary outcome was remission of proteinuria. The median dose of ACTH was 80 units injected subcutaneously twice weekly. Treatment durations were not uniform.

RESULTS

Twenty-two patients had received immunosuppression (mean, 2.2 medications) before ACTH therapy. Six patients had steroid-dependent and 15 had steroid-resistant FSGS. At the time of ACTH initiation, the median serum creatinine (interquartile range) was 2.0 (1.1-2.7) mg/dl, estimated GFR was 36 (28-78) ml/min per 1.73 m(2), and urine protein-to-creatinine ratio was 4595 (2200-8020) mg/g. At the end of ACTH therapy, 7 of 24 patients (29%) experienced remission (n=2 complete remissions, n=5 partial remissions). All remitters had steroid-resistant (n=5) or steroid-dependent (n=2) FSGS. Two responders relapsed during the follow-up period (mean ± SD, 70±31 weeks). Adverse events occurred in 21 of 24 patients, including one episode of new-onset diabetes that resolved after stopping ACTH and two episodes of AKI.

CONCLUSIONS

Response to ACTH treatment among steroid-resistant or steroid-dependent patients with FSGS is low, but ACTH gel may be a viable treatment option for some patients with resistant nephrotic syndrome due to idiopathic FSGS. Further research is necessary to determine which patients will respond to therapy.

The treatment of minimal change disease in adults

Minimal change disease (MCD) is the etiology of 10%-25% of cases of nephrotic syndrome in adults. The mainstay of treatment for adult MCD, oral glucocorticoids, is based on two randomized controlled trials and extensive observational data in adults, and this treatment leads to remission in over 80% of cases. Relapses are common, and some patients become steroid-resistant (SR), steroid-dependent (SD), or frequently relapsing (FR). The data guiding the treatment of these patients are limited. Here, we review MCD in adults with particular focus on the evidence for immunosuppressive therapy in these patients.

Tacrolimus versus cyclophosphamide in steroid-dependent or steroid-resistant focal segmental glomerulosclerosis: a randomized controlled trial

BACKGROUND

The efficacy and safety of tacrolimus (TAC) and cyclophosphamide (CTX) were prospectively examined in steroid-dependent or steroid-resistant primary focal segmental glomerulosclerosis (FSGS).

METHODS

Patients with biopsy-proven FSGS were enrolled and randomly divided into two groups: CTX and TAC. Patients treated with CTX (0.5-0.75 g/m(2)·month, i.v.) received prednisone at 0.8 mg/kg·day, while patients treated with TAC (0.1 mg/kg·day) received prednisone at 0.5 mg/kg·day. The plasma concentration of TAC was monitored and maintained at 5-10 ng/ml. After a 6-month treatment the patients were evaluated. Patients with complete remission (CR) and partial remission (PR) continued the treatment for 12 months with the dose tapered, whereas the patients with no response were excluded from the study and underwent an alternative treatment.

RESULTS

A total of 33 patients were recruited and 27 completed the 12-month follow-up. The TAC-treated patients (n = 15) showed a quick remission. The initial remission time averaged 1.23 ± 0.21 versus 2.21 ± 0.77 months in the CTX group (n = 18), but no significant difference was achieved (p > 0.05). At 6 months, the two groups showed a similar outcome. Ten patients from each group showed remission (7 CR and 3 PR). At 12 months, the CTX group had 9 CR and 3 PR while the TAC group had 6 CR and 5 PR. Remission rates in TAC tended to be higher than that in CTX, but there was no difference. CTX patients had a high prevalence of infections (50.0 vs. 13.3% in TAC, p < 0.05). In contrast, TAC-treated patients showed a high incidence of hyperglycemia (26.7 vs. 0.0% in CTX, p < 0.05).

CONCLUSION

These results suggest that CTX and TAC had a similar efficacy in steroid-dependent and steroid-resistant FSGS as manifested by reduced proteinuria, improved serum albumin level and renal function.

Tacrolimus is an alternative therapy option for the treatment of adult steroid-resistant nephrotic syndrome: a prospective, multicenter clinical trial

BACKGROUND

The optimal therapy for adult steroid-resistant nephrotic syndrome (SRNS) remains a therapeutic challenge. We investigated the efficacy and safety of tacrolimus as a promising regimen in Chinese adult patients.

METHODS

A prospective, multicenter trial was conducted in 9 nephrology centers from 2006 to 2008, in patients with SRNS (defined as failure to respond to 1 mg/kg/day of prednisone for 8, and 16 weeks, in focal segmental glomerulosclerosis). Patients were treated with tacrolimus (TAC) plus prednisone for 12 months. TAC dose was titrated to achieve a target trough blood concentration of 5-10 ng/ml for the first 6 months and 4-6 ng/ml for the subsequent 6 months. The primary outcomes included complete or partial remission [complete remission (CR): proteinuria <0.3 g/24 h, with serum albumin ≥ 3.5 g/dl and stable renal function; partial remission (PR): proteinuria between 0.3 and 3.5 g/24 h and a decrease of at least 50 % from the baseline level, with serum albumin ≥ 3.0 g/dl and stable renal function]. Secondary end-points included relapse rate, changes of clinical parameters (proteinuria, serum albumin, and lipid profile) and adverse events.

RESULTS

Twenty-four patients with SRNS were enrolled. After 6 months of therapy, CR was achieved in 58.3 % of patients and PR in 16.7 %, yielding a final response rate of 75.0 %. The decrease in proteinuria was 43.1 ± 17.5 % after the first month of treatment (P < 0.001). Complete or PR was achieved in 6 of 8 patients with minimal change disease, 4 of 6 patients with mesangioproliferative glomerulonephritis (MsPGN), 6 of 7 patients with focal segmental glomerulosclerosis (FSGS), and all 2 patients with IgA nephropathy. Two patients (1 with MsPGN and 1 with FSGS) experienced relapses during the subsequent 6 months of follow-up. Adverse events included infection, hand tremor, diarrhea, acute reversible or persistent nephrotoxicity.

CONCLUSIONS

In conjunction with prednisone, TAC may be an alternative therapeutic regimen for adult SRNS patients. However, adverse events in these patients should be carefully monitored, especially at the beginning of treatment. Randomized controlled trials with longer follow-up are warranted.

Tacrolimus is an alternative therapeutic option for the treatment of refractory lupus nephritis

We conducted an open-labeled, prospective study to determine the efficacy and safety of tacrolimus as an alternative therapeutic option for those patients with refractory lupus nephritis. The study population comprised one male and eight female patients with diffuse proliferative lupus nephritis. All patients had failed to respond to sufficient intravenous cyclophosphamide therapy with proteinuria of >or=1 g/day and active urinary sediments. Tacrolimus (0.1 mg/kg/day) was administered for 1 year with adjusting drug level (4-10 microg/l). The mean serum creatinine level and spot urine protein creatinine ratio (UPCR) at baseline were 1.39 mg/dl and 2.27, respectively. After the treatment, proteinuria reduced significantly from median UPCR value of 2.19 (range, 1.19-3.34) to 0.44 (range, 0.12-2.13) (p < 0.05). Seven (78%) of the nine patients showed a complete clinical response, which was defined as stabilization in the disease-activity markers and serum creatinine level with reduction of >or=50% in UPCR; two patients showed complete remission with UPCR <0.2. One patient showed treatment failure because of the disease progression. No serious adverse effects were observed during the study. This study demonstrates that tacrolimus can show a significant therapeutic response in cases that are refractory to the standard regimen for diffuse proliferative lupus nephritis.

The podocyte as a direct target of immunosuppressive agents

Podocytes play a key role in maintaining the blood-urine barrier for high-molecular-weight proteins. They are considered to be terminally differentiated, and podocyte loss cannot be compensated by regenerative proliferation. Various diseases leading to podocyte damage and loss result in proteinuria and cause nephrotic syndrome. Therefore, direct therapeutical strategies to protect podocytes in disease situations are a logical concept to prevent disease or to delay disease progression. Acquired podocytopathies like idiopathic focal segmental glomerulosclerosis and minimal change disease are historically considered as immunological diseases. Therefore, immunosuppressive agents such as steroids and calcineurin inhibitors are the commonly used treatment strategies. However, the causative disease mechanisms behind these treatment strategies remain elusive. Recent evidence shows that immunosuppressive agents, in addition to the effect on the immune system, directly influence the unique structure and function of podocytes. In this context, the actin cytoskeleton of the podocyte and cytokines such as vascular endothelial growth factor play a pivotal role. In this review, we summarize the direct effects on podocytes obtained in vivo and in vitro after treatment with calcineurin inhibitors, mTOR inhibitors and glucocorticoids. These direct effects could play a key role in the treatment concepts of podocytopathies with an important impact on the long-term renal function in patients with pharmacological immunosuppression.

Long-term outcome of children with steroid-resistant nephrotic syndrome treated with tacrolimus

We report the outcome of our single-center, long-term follow-up study of tacrolimus therapy in children with steroid-resistant nephrotic syndrome (SRNS). All cases of nephrotic syndrome (NS) with kidney biopsies treated at our center between January 2000 and July 2008 were reviewed. Children with systemic lupus erythematosus and steroid-dependent NS were excluded. Nineteen children with SRNS received tacrolimus. Histopathological analysis of the biopsy revealed the underlying conditions of these 19 patients to be focal segmental glomerulosclerosis (ten patients), C1q nephropathy (four), membranous nephropathy (two), minimal change disease (one), membranoproliferative glomerulonephritis (one), and immunoglobulin A nephropathy (one). The mean follow-up was 55 months, and the median age of the patient cohort was 10 years. We observed complete remission in 11 (58%) patients, partial remission in six (32%), and failure to respond in two (9%). The median time to response was 8 weeks. Side effects were mild and transient (one case of acute kidney injury and three cases of hyperglycemia). The initial rate for combined partial and complete remission of the NS in children with SRNS was 81%, which was sustained in 58% of the patients on follow-up. Among children with FSGS, the sustained remission rate was 50%, while 40% progressed to end-stage renal disease (ESRD) (mean time 52 months). Based on the results of this study, we conclude that tacrolimus is an effective and well-tolerated therapeutic option for the treatment of SRNS in children. However, the occurrence of relapses of the NS with progression to ESRD during the long-term follow-up indicates the need for careful monitoring of such patients.

Pharmacotherapeutic review and update of idiopathic nephrotic syndrome in children

AIM OF THE REVIEW

The therapeutic management of pediatric idiopathic nephrotic syndrome is still a challenge due to the large number of potentially effective pharmacological alternatives and the insufficient scientific evidence available. A bibliographic review was performed in order to identify the available pharmacological alternatives, as well as their place in therapy, and to analyze whether the treatment algorithm developed by the pediatric nephrology department of our hospital is consistent with the evidence published to date.

METHOD

A literature search was carried out on MEDLINE, through PubMed, using the medical subject heading (MeSH) nephrotic syndrome. The search was limited to review papers, meta-analyses, clinical practice guidelines, and randomized controlled trials performed on pediatric populations up to September 2009.

RESULTS

The treatment algorithm established in our hospital is consistent with the evidence available. Prednisone constitutes the first line treatment with evidence level Ia. When corticosteroids do not achieve remission, there are other therapeutic options that are not clearly positioned yet and further studies that provide more information on their comparative efficacy and safety are needed. These alternative therapeutic options are cyclosporine, mycophenolate mofetil, levamisol, cyclophosphamide and methylprednisolone, as independent strategies or as part of "Mendoza Protocol", tacrolimus and rituximab. Their sequence of introduction in the therapeutic scheme of NS is classified as evidence level IV and grade D recommendation.

CONCLUSION

The wide range of options available for the pharmacotherapeutic management of NS and the lack of evidence about the comparative efficacy and safety of the different therapeutic strategies, make its positioning rather difficult. Therefore each hospital needs to draw up protocols based not only on the small amount of evidence available, but also on the authorized indications, availability of the drugs, clinical experience, associated costs, and patient preferences with regard to the duration of treatment, incidence and type of adverse effects. Development of new randomized controlled trials should be encouraged and setting up national plans for the treatment of this pathology might be a good approach for this problem.

Remission of steroid-resistant nephrotic syndrome due to focal and segmental glomerulosclerosis using rituximab

BACKGROUND

Therapeutic options are limited in cases of focal and segmental glomerulosclerosis (FSGS) that fail to respond to steroids and calcineurin inhibitors. We describe a case in which steroid-resistant nephrotic syndrome (SRNS) secondary to FSGS did not respond to conventional treatment, but was successfully treated with rituximab. Unlike previous reports in which rituximab was used in conjunction with a calcineurin inhibitor, we present the first case where rituximab was used as the sole therapeutic agent.

CASE REPORT

An 11-month-old boy presented with severe manifestations of primary nephrotic syndrome with a subsequent non-responsive steroid course. A renal biopsy confirmed FSGS, with normal staining for podocin and nephrin. Genetic studies for podocin were normal. The child developed ciclosporin-induced hemolytic uremic syndrome (HUS), and the response to plasma exchange, following ciclosporin withdrawal, was only temporary. A trial of a combination of mycophenolate and dexamethasone did not have any effect on proteinuria or fluid status. Four weekly rituximab infusions at 375 mg/m2/dose induced a complete remission without any adverse effects.

CONCLUSIONS

This case suggests that rituximab may be used as the sole therapeutic agent in the treatment of SRNS secondary to FSGS, especially in cases where calcineurin inhibitors are contraindicated.

Corticosteroid-resistant nephrotic syndrome with focal and segmental glomerulosclerosis : an update of treatment options for children

Corticosteroid-resistant nephrotic syndrome (CRNS) with focal and segmental glomerulosclerosis (FSGS) is a heterogeneous disorder and the most severe and frequent type of all glomerulopathies in children leading to end-stage renal failure. The podocyte is at the center of development and progress of FSGS; this unique cell type plays a major role in the integrity of glomerular structure and permeability. The rate of complete remission of CRNS after induction therapy using different immunosuppressant agents is reported to range between 30% and 84%, depending on the treatment schedule and on the underlying defects of FSGS. Children with genetic types of FSGS barely respond to immunosuppressant therapies and over-treatment prior to transplantation should be avoided. The response of children with an idiopathic type of FSGS to immunosuppressants is superior to those with genetic FSGS. However, many children with idiopathic FSGS do not enter complete remission if they are under-treated, for example, with short-term immunosuppressant monotherapies. If immunosuppressant treatment fails, these patients will have to undergo renal transplantation. However, as unknown pathogenetic mechanisms may persist, more than one-third of these patients with idiopathic FSGS develop a rapid recurrence of CRNS that responds poorly to further long-term therapeutic attempts. In contrast with previously published data, this review takes into account recently identified genetic etiologies of CRNS, and superior results with long-term combination therapy in idiopathic forms to avoid over- and under-treatment.

Interventions for minimal change disease in adults with nephrotic syndrome

BACKGROUND

Steroids have been used widely since the early 1970s for the treatment of adult-onset minimal change disease. The response rates to immunosuppressive agents in adult minimal change disease, especially steroids, are more variable than in children. The optimal agent, dose, and duration of treatment for the first episode of nephrotic syndrome, or for disease relapse(s) has not been determined.

OBJECTIVES

To determine the benefits and harms of interventions for the nephrotic syndrome in adults caused by minimal change disease.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, reference articles and abstracts from conference proceedings, without language restriction. Search date: January 2007.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of any intervention for minimal change disease in adults over 18 years with the nephrotic syndrome were included. Studies comparing different routes, frequencies, and duration of immunosuppressive agents were selected. Studies comparing non-immunosuppressive agents were also assessed.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random effects model and results were expressed as a relative risk (RR) for dichotomous outcomes, or mean difference (WMD) for continuous data with 95% confidence intervals (CI).

MAIN RESULTS

Three RCTs (68 participants) were identified. All treatment comparisons contained only one study. No significant difference was found between prednisone compared with placebo for complete (RR 1.44, CI 0.95 to 2.19) and partial remission (RR 1.00, CI 0.07 to 14.45) of the nephrotic syndrome due to minimal change disease. There was no difference between intravenous methylprednisolone plus oral prednisone compared with oral prednisone alone for complete remission (RR 0.74, CI 0.50 to 1.08). Prednisone, compared with short-course intravenous methylprednisolone, increased the number of subjects who achieved complete remission (RR 4.95, CI 1.15 to 21.26). The lack of statistical evidence of efficacy associated with prednisone therapy was based on data derived from a single study that compared 'alternate-day prednisone' to no immunosuppression' with only a small number of participants in each group. No RCTs were identified comparing regimens in adults with a steroid-dependent or relapsing disease course or comparing treatments comprising alkylating agents, cyclosporine, tacrolimus, levamisole, or mycophenolate mofetil.

AUTHORS' CONCLUSIONS

Further comparative studies are required to examine the efficacy of immunosuppressive agents for achievement of sustained remission of nephrotic syndrome caused by minimal change disease. Studies are also needed to evaluate treatments for adults with steroid-dependent or relapsing disease.

Revised guidelines for management of steroid-sensitive nephrotic syndrome

JUSTIFICATION

In 2001, the Indian Pediatric Nephrology Group formulated guidelines for management of patients with steroid-sensitive nephrotic syndrome. In view of emerging scientific evidence, it was felt necessary to review the existing recommendations.

PROCESS

Following a preliminary meeting in March 2007, a draft statement was prepared and circulated among pediatric nephrologists in the country to arrive at a consensus on the evaluation and management of these patients.

OBJECTIVES

To revise and formulate recommendations for management of steroid-sensitive nephrotic syndrome.

RECOMMENDATIONS

The need for adequate corticosteroid therapy at the initial episode is emphasized. Guidelines regarding the initial evaluation, indications for renal biopsy and referral to a pediatric nephrologist are updated. It is proposed that patients with frequently relapsing nephrotic syndrome should, at the first instance, be treated with longterm, alternate-day prednisolone. The indications for use of alternative immunosuppressive agents, including levamisole, cyclophosphamide, mycophenolate mofetil, and cyclosporin are outlined. The principles of dietary therapy, management of edema, and prevention and management of complications related to nephrotic syndrome are described. These guidelines, formulated on the basis of current best practice, are aimed to familiarize physicians regarding principles of management of children with steroid-sensitive nephrotic syndrome.

Tacrolimus in the treatment of idiopathic nephrotic syndrome

The immunosuppressant tacrolimus (FK-506) is a calcineurin inhibitor with a widespread use for the prevention of graft rejection in transplantation medicine. Tacrolimus inhibits the activation of an essential transcription factor for the transcription of cytokine genes in T cells leading to a decreased production of cytokines such as IL-2 and IFN-gamma. As T-cell activation plays a crucial role in the pathogenesis of inflammatory glomerular diseases, there is an increasing number of reports on the use of tacrolimus in nephrotic syndrome. In idiopathic nephrotic syndrome, corticosteroid treatment constitutes the first-line therapy to achieve remission. In the case of steroid resistance or steroid dependence, alternative immunosuppressive strategies are needed. Cyclophosphamide and ciclosporin are well-established drugs in this condition. The present article reviews the pharmacodynamics, pharmacokinetics, safety and clinical efficacy of tacrolimus in steroid-resistant and steroid-dependent nephrotic syndrome.