Interventions for minimal change disease in adults with nephrotic syndrome

Nicorandil protects podocytes via modulation of antioxidative capacity in acute puromycin aminonucleoside-induced nephrosis in rats

Nephrotic syndrome, characterized by proteinuria and hypoalbuminemia, results from the dysregulation of glomerular podocytes and is a significant cause of end-stage kidney disease. Patients with idiopathic nephrotic syndrome are generally treated with immunosuppressive agents; however, these agents produce various adverse effects. Previously, we reported the renoprotective effects of a stimulator of the mitochondrial ATP-dependent K⁺ channel (MitK_ATP), nicorandil, in a remnant kidney model. Nonetheless, the cellular targets of these effects remain unknown. Here, we examined the effect of nicorandil on puromycin aminonucleoside-induced nephrosis (PAN) rats, a well-established model of podocyte injury and human nephrotic syndrome. PAN was induced using a single intraperitoneal injection. Nicorandil was administered orally at 30 mg/kg/day. We found that proteinuria and hypoalbuminemia in PAN rats were significantly ameliorated following nicorandil treatment. Immunostaining and ultrastructural analysis under electron microscopy demonstrated that podocyte injury in PAN rats showed a significant partial attenuation following nicorandil treatment. Nicorandil ameliorated the increase in the oxidative stress markers nitrotyrosine and 8-hydroxy-2-deoxyguanosine in glomeruli. Conversely, nicorandil prevented the decrease in levels of the antioxidant enzyme manganese superoxide dismutase in PAN rats. We found that mitochondrial Ca²⁺ uniporter levels in glomeruli were higher in PAN rats than in control rats, and this increase was significantly attenuated by nicorandil. We conclude that stimulation of MitK_ATP by nicorandil reduces proteinuria by attenuating podocyte injury in PAN nephrosis, which restores mitochondrial antioxidative capacity, possibly through mitochondrial Ca²⁺ uniporter modulation. These data indicate that MitK_ATP may represent a novel target for podocyte injury and nephrotic syndrome.NEW & NOTEWORTHY Our findings suggest that the mitochondrial Ca²⁺ uniporter may be an upstream regulator of manganese superoxide dismutase and indicate a biochemical basis for the interaction between the ATP-sensitive K⁺ channel and Ca²⁺ signaling. We believe that our study makes a significant contribution to the literature because our results indicate that the ATP-sensitive K⁺ channel may be a potential therapeutic target for podocyte injury and nephrotic syndrome.

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 (MCD). Recently, newer agents have been used in adult MCD aiming to reduce the risk of adverse effects. The response rates to immunosuppressive agents in adult MCD 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) have not been determined. This is an update of a review first published in 2008.

OBJECTIVES

We aimed to 1) evaluate the benefits and harms of different agents, including both immunosuppressive and non-immunosuppressive agents, in adults with MCD causing the nephrotic syndrome; and 2) evaluate the efficacy of interventions on 'time-to-remission' of nephrotic syndrome, in adults with MCD causing the nephrotic syndrome.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 21 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of any intervention for MCD with nephrotic syndrome in adults over 18 years were included. Studies comparing different types, routes, frequencies, and duration of immunosuppressive agents and non-immunosuppressive agents were 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 risk ratio (RR) for dichotomous outcomes, or mean difference (MD) for continuous data with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Fifteen RCTs (769 randomised participants) were identified; four studies evaluated different prednisolone regimens, eight studies evaluated the calcineurin inhibitors (CNIs) (tacrolimus or cyclosporin), two studies evaluated enteric-coated mycophenolate sodium (EC-MPS) and one study evaluated levamisole. In all but two studies of non-corticosteroid agents, reduced-dose prednisolone was given with the treatment agent and the comparator was high-dose prednisolone. In the risk of bias assessment, 11 and seven studies were at low risk of bias for sequence generation and allocation concealment, respectively. No studies were at low risk of performance bias and eight studies were at low risk of detection bias. Thirteen, 10 and six studies were at low risk of attrition bias, reporting bias and other bias, respectively. Compared with no specific treatment, it is uncertain whether prednisolone increases the number with complete remission (1 study, 28 participants: RR 1.44, 95% CI 0.95 to 2.19), complete or partial remission (1 study, 28 participants: RR 1.38, 95% CI 0.98 to 1.95), subsequent relapse (1 study, 28 participants: RR 0.75, 95% CI 0.48 to 1.17), or reduces the adverse effects because the certainty of the evidence is very low. Compared with oral prednisolone alone, it is uncertain whether intravenous methylprednisolone and prednisolone increase the number with complete remission (2 studies, 35 participants: RR 1.76, 95% CI 0.17 to 18.32; I² = 90%), relapse (two studies, 19 participants. RR 1.18, 95% CI 0.65 to 2.15; I² = 0%) or adverse events because the certainty of the evidence is very low. Compared with prednisolone alone, CNIs with reduced-dose prednisolone or without prednisolone probably make little or no difference to the number achieving complete remission (8 studies; 492 participants: RR 0.99, 95% CI 0.93 to 1.05; I² = 0%), complete or partial remission (4 studies, 269 participants: RR 1.01, 95% CI 0.96 to 1.05; I² = 0%), or relapse (7 studies; 422 participants: RR 0.73, 95% CI 0.51 to 1.03; I² = 0%) (moderate certainty evidence), may reduce the risk of obesity or Cushing's Syndrome (5 studies; 388 participants: RR 0.11, 95% CI 0.02 to 0.59; I² = 45%) and the risk of acne (4 studies; 270 participants: RR 0.15, 95% CI 0.03 to 0.67; I² = 0%) (low certainty evidence); and had uncertain effects on diabetes or hyperglycaemia, hypertension, and acute kidney injury (AKI) (low certainty evidence). Compared with prednisolone alone, EC-MPS with reduced-dose prednisolone probably make little or no difference to the number undergoing complete remission at 4 weeks (1 study, 114 participants: RR 1.12, 95% CI 0.84 to 1.50), and at 24 weeks probably make little or no difference to the number undergoing complete remission (2 studies, 134 participants: RR 1.12, 95% CI 0.84 to 1.38; I² = 0%) (moderate certainty evidence), complete or partial remission (2 studies 134 participants: RR 0.92, 95% CI 0.75 to 1.12; I² = 0%), relapse (2 studies, 83 participants: RR 0.50, 95% CI 0.07 to 3.74; I² = 56%) (low certainty evidence); or to the adverse events of new-onset glucose intolerance, death, or AKI (low certainty evidence). One study (24 participants) compared levamisole and prednisolone with prednisolone in patients with relapsing disease. The authors identified no differences in mean relapse rate or adverse effects but no standard deviations were provided.

AUTHORS' CONCLUSIONS

This updated review has identified evidence for the efficacy and adverse effects of CNIs and EC-MPS with or without reduced-dose prednisolone compared with prednisolone alone for the induction of remission in adults with MCD and nephrotic syndrome with some reductions in steroid-associated adverse events. RCT data on the efficacy and adverse effects of rituximab in adults with MCD are awaited. Further, adequately powered RCTs are required to determine the relative efficacies of CNIs and EC-MPS and to evaluate these medications in patients with relapsing or steroid-resistant disease.

Respiratory Tract Infection: A Risk Factor for the Onset and Relapse of Adult-Onset Minimal Change Disease in Southern China

AIMS/INTRODUCTION

Steroid resistance and frequent relapse are problems in the treatment of minimal change disease (MCD). However, epidemiological factors that influence steroid-resistant and relapse of MCD are rarely reported. This study evaluated potential factors that influence the onset and relapse of MCD and the epidemiological features of southern Chinese patients with adult-onset MCD.

PATIENTS AND METHODS

Patients with adult-onset MCD were included from the Affiliated Hospital of Guangdong Medical University, which is located in the southernmost part of China's mainland, between 2015 and 2016. Potential influencing factors were investigated.

RESULTS

Eighty-seven patients with incipient MCD were enrolled, and 85 of these patients were followed up; 71.8% (61/85) were steroid-sensitive and 28.2% (24/85) were steroid-resistant. In terms of seasonal distribution, the highest rate of incipient cases was in spring (39.1%, 34/87), which also showed a high rate of relapse cases (29.7%, 22/74). Among patients who were followed up for more than half a year and whose proteinuria completely resolved (69.4%, 59/85), 52.5% (31/59) were without relapse and 47.5% (28/59) were with relapse. Patients without relapse were older than those with relapse (P<0.05). Before disease onset, 20.7% (18/87) of patients with incipient MCD were diagnosed with infection, including 94.5% (17/18) with respiratory tract infection. Fourteen patients in complete remission posttreatment developed an infection before relapse, including 85.7% (12/14) with respiratory tract infection.

CONCLUSION

Steroid resistance and frequent relapse are current challenges for the treatment of adult-onset MCD in southern China, and respiratory tract infection may be a risk factor for onset and relapse. Additionally, younger patients with MCD tend to have more frequent relapse.

Adult minimal-change disease: observational data from a UK centre on patient characteristics, therapies, and outcomes

Background

Minimal change disease (MCD) is a common cause of the nephrotic syndrome in adults with limited evidence on its treatment and prognosis. We examined the presenting characteristics, treatments, and outcomes of adult patients with MCD in our centre.

Methods

This was an observational cohort study using retrospectively-collected data. All patients who had a renal biopsy reported as MCD between 1996 and 2012 were included, and data were collected at baseline and during follow-up. Statistical analysis included Cox-regression analysis to examine which factors were associated with risk of relapse.

Results

Seventy-eight patients were included, and had a median age of 36 years, and were 60% male and 73% white. Median follow-up time was 72 months. 37% were in AKI at presentation, which was significantly associated with a lower serum albumin and older age. Although 10% were steroid-resistant, 98% achieved remission at a median time of 5 weeks. 61% relapsed, at a median time of 11 months, and patients had a median number of 2 relapses during follow-up. A higher eGFR was associated with an increased risk of relapse (hazard ratio 1.18 [1.03–1.36] per 10 mL/min increase in eGFR), and females were significantly more likely than males to have an early relapse. Nearly half of the cohort required an additional immunosuppressive agent on top of glucocorticoids, the most commonly used being calcineurin inhibitors. Five patients subsequently developed FSGS: these patients had a lower baseline creatinine, a higher serum albumin, a longer time to remission, and were more likely to be steroid-resistant. Follow-up renal function was generally preserved, but follow-up creatinine was higher in those who had presented with AKI, and in those who had been commenced on a RAS inhibitor after biopsy. Infection requiring admission, diabetes mellitus and venous thromboembolism developed in 14%, 12%, and 12% of patients respectively.

Conclusions

Nearly all adults with MCD achieve remission, but relapses and disease- and therapy-related complications are common. In our cohort, eGFR and gender were associated with risk of relapse, and these previously undescribed associations could be explored further in future work.

Rituximab as a front-line therapy for adult-onset minimal change disease with nephrotic syndrome

Minimal change disease (MCD) accounts for 15% of adult nephrotic syndrome (NS) cases. Adult-MCD patients may have more severe clinical features than pediatric patients. In children, Rituximab (RTX) has been used since 2006 to treat frequently relapsing NS. In adults, data about the efficacy of RTX for MCD are limited. We report our experience on the use of RTX in adult biopsy-proven MCD. Our series includes 6 adult patients (2 males and 4 females), age 45–73 years, treated with RTX (4 weekly doses of 375 mg/m²). Proteinuria decreased from 11,2 (23–4.8) g/24 hours to 0.6 (0–2) g/24 hours after 6 months, and to 0.4 (0–1, 4) g/24 h in the 4 pts with the longer follow-up. Creatinine decreased from 1.95 (0.5–5) mg/dl to 0.88 (0.6–1.3) mg/l. Five patients achieved a complete renal remission, while in 1 pt proteinuria decreased by 75%. RTX successfully depleted CD19 lymphocytes in 100% of pts for at least 6 months. No clinically relevant adverse events have been observed. This case series shows a remarkable efficacy of RTX in treatment of MCD. RTX can be an attractive alternative both in recurrent forms and in induction-therapy of MCD. RTX may be preferentially used in patients at a high risk of development of the adverse effects of corticosteroids and should be considered as an alternative option in patients with recurrent NS. Additional data are needed to inform clinical practice on how best to use RTX in this patient population, so that definitive randomized trials can be planned.

The Evolving Role of Rituximab in Adult Minimal Change Glomerulopathy

BACKGROUND

Minimal-change glomerulopathy is defined histologically by the presence of normal glomeruli on light microscopy and diffuse podocyte effacement on electron microscopy. Although effective in children, corticosteroid treatment in adults is more variable and time to response can be prolonged. Data to support rituximab use in adults with corticosteroid-dependent or resistant minimal-change glomerulopathy are limited. Here, we describe the clinical course of adults with corticosteroid-dependent or -resistant minimal-change glomerulopathy who received rituximab.

METHODS

Demographic and clinical data were collected and analyzed from all adult patients with native kidney, biopsy-proven, minimal-change glomerulopathy who were administered rituximab between 2009 and 2014 and cared for at the UNC Kidney Center.

RESULTS

Ten patients with corticosteroid-resistant (n = 5) or corticosteroid-dependent (n = 5) idiopathic minimal-change glomerulopathy were treated with rituximab between 2009 and 2014. Rituximab treatment induced remission in all 10 patients with a median time to remission of 2 months. The median time from rituximab to corticosteroid discontinuation was 3.5 months. The median remission time was 29 months and follow-up time was 39.5 months. No serious adverse events attributable to rituximab were observed.

CONCLUSION

Rituximab induced remission in all patients with corticosteroid-dependent or -resistant minimal-change glomerulopathy, and may hold great therapeutic potential with good efficacy and minimal toxicity. Mounting evidence implies that a well-conducted randomized controlled clinical trial using rituximab in adults with minimal-change glomerulopathy in both corticosteroid-resistant and corticosteroid-dependent patients is warranted.

Minimal Change Disease

Minimal change disease (MCD) is a major cause of idiopathic nephrotic syndrome (NS), characterized by intense proteinuria leading to edema and intravascular volume depletion. In adults, it accounts for approximately 15% of patients with idiopathic NS, reaching a much higher percentage at younger ages, up to 70%-90% in children >1 year of age. In the pediatric setting, a renal biopsy is usually not performed if presentation is typical and the patient responds to therapy with oral prednisone at conventional doses. Therefore, in this setting steroid-sensitive NS can be considered synonymous with MCD. The pathologic hallmark of disease is absence of visible alterations by light microscopy and effacement of foot processes by electron microscopy. Although the cause is unknown and it is likely that different subgroups of disease recognize a different pathogenesis, immunologic dysregulation and modifications of the podocyte are thought to synergize in altering the integrity of the glomerular basement membrane and therefore determining proteinuria. The mainstay of therapy is prednisone, but steroid-sensitive forms frequently relapse and this leads to a percentage of patients requiring second-line steroid-sparing immunosuppression. The outcome is variable, but forms of MCD that respond to steroids usually do not lead to chronic renal damage, whereas forms that are unresponsive to steroids may subsequently reveal themselves as FSGS. However, in a substantial number of patients the disease is recurrent and requires long-term immunosuppression, with significant morbidity because of side effects. Recent therapeutic advances, such as the use of anti-CD20 antibodies, have provided long-term remission off-therapy and suggest new hypotheses for disease pathogenesis.

Therapeutic variability in adult minimal change disease and focal segmental glomerulosclerosis

Background

Variability in the management of glomerulonephritis may negatively impact efficacy and safety. However, there are little/no data on actual variability in the treatment of minimal change disease (MCD)/focal segmental glomerulosclerosis (FSGS) in adults. We assessed Spanish practice patterns for the management of adult nephrotic syndrome due to MCD or FSGS. The absence of reasonably good evidence on treatment for a disease often increases the variability substantially. Identification of evidence–practice gaps is the first necessary step in the knowledge-to-action cyclical process. We aim to analyse the real clinical practice in adults in hospitals in Spain and compare this with the recently released Kidney Disease: Improving Global Outcomes clinical practice guideline for glomerulonephritis.

Methods

Participating centres were required to include all adult patients (age >18 years) with a biopsy-proven diagnosis of MCD or FSGS from 2007 to 2011. Exclusion criteria included the diagnosis of secondary nephropathy.

Results

We studied 119 Caucasian patients with biopsy-proven MCD (n = 71) or FSGS (n = 48) from 13 Spanish hospitals. Of these patients, 102 received immunosuppressive treatment and 17 conservative treatment. The initial treatment was steroids, except in one patient in which mycophenolate mofetil was used. In all patients, the steroids were given as a single daily dose. The mean duration of steroid treatment at initial high doses was 8.7 ± 13.2 weeks and the mean global duration was 38 ± 32 weeks. The duration of initial high-dose steroids was <4 weeks in 41% of patients and >16 weeks in 10.5% of patients. We did find a weak and negative correlation between the duration of whole steroid treatment in the first episode and the number of the later relapses (r = −0.24, P = 0.023). There were 98 relapses and they were more frequent in MCD than in FSGs patients (2.10 ± 1.6 versus 1.56 ± 1.2; P = 0.09). The chosen treatment was mainly steroids (95%). Only seven relapses were treated with another drug as a first-line treatment: two relapses were treated with mycophenolate and five relapses were treated with anticalcineurinics. A second-line treatment was needed in 29 patients (24.4%), and the most frequent drugs were the calcineurin inhibitors (55%), followed by mycophenolate mofetil (31%). Although cyclophosphamide is the recommended treatment, it was used in only 14% of the patients.

Conclusions

We found variation from the guidelines in the duration of initial and tapered steroid therapy, in the medical criteria for classifying a steroid-resistant condition and in the chosen treatment for the second-line treatment. All nephrologists started with a daily dose of steroids as the first-line treatment. The most frequently used steroid-sparing drug was calcineurin inhibitors. Cyclophosphamide use was much lower than expected.

Enhanced Steroid Therapy in Adult Minimal Change Nephrotic Syndrome: A Systematic Review and Meta-analysis

The best regimen for adult minimal change nephrotic syndrome (MCNS) is still unknown. Due to an excessive number of adverse events caused by oral steroid monotherapy, enhanced steroid therapy (low dose of prednisolone with a short course of methylprednisolone or with another immunosuppressant) has been studied extensively for years. In this study, the PubMed, Embase, EBSCO and Cochrane Library databases were searched for clinical trials which compared enhanced steroid therapy with oral steroid monotherapy in adult MCNS and a meta-analysis was performed. Seven studies involving 357 patients were included. We found that patients treated with enhanced steroid therapy responded more quickly to complete remission (CR) [mean difference = -9.52, 95% confidence interval (CI): -12.66--6.39, p<0.00001] and showed fewer adverse events [risk radio (RR) = 0.72, 95% CI: 0.54-0.97, p=0.03] than patients receiving oral steroid monotherapy. The CR rate (RR= 0.96, 95% CI: 0.83-1.10, p=0.53) and relapse rate (RR=0.87, 95% CI: 0.57-1.34, p=0.53) were similar in both groups.

KDOQI US commentary on the 2012 KDIGO clinical practice guideline for glomerulonephritis

Glomerulonephritis (GN) is an important cause of morbidity and mortality in patients of all ages throughout the world. Because these disorders are relatively rare, it is difficult to perform randomized clinical trials to define optimal treatment for many of the specific glomerulopathies. In the absence of high-grade evidence to guide the care of glomerular diseases, in June 2012, KDIGO (Kidney Disease: Improving Global Outcomes) published an international clinical guideline for GN. The Work Group report represents an important review of the literature in this area and offers valid and useful guidelines for the most common situations that arise in the management of patients with glomerular disease. This commentary, developed by a panel of clinical experts convened by the National Kidney Foundation, attempts to put the GN guideline into the context of the US health care system. Overall, we support the vast majority of the recommendations and highlight select areas in which epidemiological factors and medical practice patterns in this country justify modifications and adjustments in order to achieve favorable outcomes. There remain large gaps in our knowledge of the best approaches to treat glomerular disease and we strongly endorse an expanded clinical research effort to improve the health and long-term outcomes of children and adults with GN.

Chinese herbal medicine Huangqi type formulations for nephrotic syndrome

BACKGROUND

Patients with primary nephrotic syndrome mostly need immunosuppression to achieve remission, but many of them either relapse after immunosuppression therapy or resistant to it. On the other hand, immunosuppression therapy could increase the adverse effect. Huangqi and Huangqi type formulations have been used to treat nephrotic syndrome for years in China, however the effects and safety of these formulations have not been systematically reviewed. This is an update of a review first published in 2008.

OBJECTIVES

To assess the benefits and harms of Huangqi and Huangqi type formulations in treating nephrotic syndrome in any age group, either as sole agents or in addition to other drug therapies.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Chinese Biomedicine Database (CBM), CNKI, VIP and reference lists of articles. There was no language restriction.Date of search: April 2011.

SELECTION CRITERIA

All randomised controlled trials (RCTs) assessing the use of Huangqi or Huangqi type formulations in treating nephrotic syndrome in adults and children, either as sole agents or in addition to other drug therapies.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. For dichotomous outcomes results were expressed as relative risk (RR) and 95% confidence intervals (CI). Continuous outcomes were expressed as mean difference (MD) with 95% CI.

MAIN RESULTS

Nine studies were identified. One was judged to be at high risk of bias for random sequence, the rest were judged to be at low risk of bias. All studies had high risk of bias for allocation concealment and performance bias; unclear risk for detection bias and low risk for attrition bias. Two studies had unclear risk reporting bias and the rest had low risk. No other potential threats to validity were found. Compared to control interventions, Huangqi type formulations had a positive effect on plasma albumin (MD 6.41 g/dL, 95% Cl 4.24 to 8.59), urine albumin excretion (-0.57 g/24 h, 95% CI -1.04 to -0.10), cholesterol (MD -1.70 mmol/L, 95% Cl -2.60 to -1.13) and triglycerides (-0.33 mmol/L, 95% CI -0.63 to -0.03); and more patients showed improvement at three months (RR 0.41, 95% CI 0.20 to 0.84). There was no significant difference between Huangqi type formulations and control interventions for complete (RR 1.59, 95% CI 0.29 to 8.65) or partial remission (RR 1.22, 95% CI 0.57 to 2.58). While some formulations showed improvement in the number of patients achieving complete or partial remission, the number of studies (usually one per formulation), and the number patients (ranging from 38 to 78) were small. Relapse was reported at varying time points, ranging from three months to three years, and therefore these results were not pooled. Complications of nephrotic syndrome and adverse events were only reported by two studies; Only one study reported complications of nephrotic syndrome (infection) and another reported adverse reactions to treatment (Cushing's syndrome, steroid withdrawal syndrome, respiratory tract infection, and upper gastrointestinal haemorrhage). Both studies reported those treated with Huangqi type formulations had significantly less complications or adverse reactions.

AUTHORS' CONCLUSIONS

Huangqi and Huangqi type formulations may have some positive effects in treating nephrotic syndrome by increasing plasma albumin and reducing urine albumin excretion, blood cholesterol and triglycerides, and decreasing the number who don't show improvement at three months. Some formulations showed an increase in the number of patients achieving complete or partial remission, however study and participant numbers were small.

Proteinuria predicts relapse in adolescent and adult minimal change disease

OBJECTIVE

This study sought to outline the clinical and laboratory characteristics of minimal change disease in adolescents and adults and establish the clinical and laboratory characteristics of relapsing and non-relapsing patients.

METHODS

We retrospectively evaluated patients with confirmed diagnoses of minimal change disease by renal biopsy from 1979 to 2009; the patients were aged >13 years and had minimum 1-year follow-ups.

RESULTS

Sixty-three patients with a median age (at diagnosis) of 34 (23-49) years were studied, including 23 males and 40 females. At diagnosis, eight (12.7%) patients presented with microscopic hematuria, 17 (27%) with hypertension and 17 (27%) with acute kidney injury. After the initial treatment, 55 (87.3%) patients showed complete remission, six (9.5%) showed partial remission and two (3.1%) were nonresponders. Disease relapse was observed in 34 (54%) patients who were initial responders (n = 61). In a comparison between the relapsing patients (n = 34) and the non-relapsing patients (n = 27), only proteinuria at diagnosis showed any significant difference (8.8 (7.1-12.0) vs. 6.0 (3.6-7.3) g/day, respectively, p = 0.001). Proteinuria greater than 7 g/day at the initial screening was associated with relapsing disease.

CONCLUSIONS

In conclusion, minimal change disease in adults may sometimes present concurrently with hematuria, hypertension, and acute kidney injury. The relapsing pattern in our patients was associated with basal proteinuria over 7 g/day.

Glomerular disease search filters for Pubmed, Ovid Medline, and Embase: a development and validation study

BACKGROUND

Tools to enhance physician searches of Medline and other bibliographic databases have potential to improve the application of new knowledge in patient care. This is particularly true for articles about glomerular disease, which are published across multiple disciplines and are often difficult to track down. Our objective was to develop and test search filters for PubMed, Ovid Medline, and Embase that allow physicians to search within a subset of the database to retrieve articles relevant to glomerular disease.

METHODS

We used a diagnostic test assessment framework with development and validation phases. We read a total of 22,992 full text articles for relevance and assigned them to the development or validation set to define the reference standard. We then used combinations of search terms to develop 997,298 unique glomerular disease filters. Outcome measures for each filter included sensitivity, specificity, precision, and accuracy. We selected optimal sensitive and specific search filters for each database and applied them to the validation set to test performance.

RESULTS

High performance filters achieved at least 93.8% sensitivity and specificity in the development set. Filters optimized for sensitivity reached at least 96.7% sensitivity and filters optimized for specificity reached at least 98.4% specificity. Performance of these filters was consistent in the validation set and similar among all three databases.

CONCLUSIONS

PubMed, Ovid Medline, and Embase can be filtered for articles relevant to glomerular disease in a reliable manner. These filters can now be used to facilitate physician searching.

Complete remission induced by tacrolimus and low-dose prednisolone in adult minimal change nephrotic syndrome: A pilot study

Background

Few clinical trials have examined the replacement of steroids with other immunosuppressive drugs as a primary treatment modality for minimal change disease (MCD) in adults. We studied the efficacy of tacrolimus to induce complete remission (CR) in adults with MCD.

Methods

We enrolled 14 adults with MCD and nephrotic-range proteinuria. All patients were treated with oral tacrolimus 0.05 mg/kg twice daily and prednisolone 0.5 mg/kg/day. CR was defined as a urine protein to creatinine ratio of<0.2 g protein/g creatinine (g/g cr). The primary outcome was cumulative percentage of CR during 16 weeks.

Results

The mean urine protein to creatinine ratio at enrollment was 10.9 g/g cr (range: 4.2–18.1 g/g cr). The trough tacrolimus level was maintained at 5.99±2.63 ng/mL. CR was achieved by 13/14 (92.8%) patients within 8 weeks. The cumulative CR rate was 7.7% (1/14), 64.2% (9/14), 71.3% (10/14), and 92.9% (13/14) at 1 week, 2 weeks, 4 weeks, and 8 weeks, respectively. The one remaining patient achieved CR at 20 weeks after treatment, who was followed up for a further 4 weeks. The mean time to achieve CR in the 14 patients was 4.64±5.11 (1–20) weeks. Three cases suffered adverse events of abdominal pain, diarrhea, or new-onset diabetes mellitus.

Conclusion

Tacrolimus and low-dose prednisolone therapy induced CR rapidly (71.3% by 4 weeks and 100% by 20 weeks) and effectively in adult patients with MCD.

Treatment of nephrotic syndrome with adrenocorticotropic hormone (ACTH) gel

Purpose:

A synthetic adrenocorticotropin (ACTH) analog has shown efficacy in Europe as primary and secondary therapy for nephrotic syndrome, but there is no published experience using the natural, highly purified ACTH gel formulation, available in the United States, for nephrotic syndrome. We therefore investigated the use of ACTH gel for nephrotic syndrome in the United States.

Patients and methods:

Twenty-one patients with nephrotic syndrome treated with ACTH gel outside of research settings in the United States, with initiation of therapy by December 31, 2009, allowing a minimum 6 months follow-up. We defined complete remission as stable renal function with proteinuria falling to <500 mg/day, and partial remission as stable renal function with >50% reduction in proteinuria from 500 to 3500 mg/day.

Results:

Twenty-one patients with nephrotic syndrome were treated: 11 with idiopathic membranous nephropathy (iMN), 4 with membranoproliferative glomerulonephritis (MPGN), 1 with focal segmental glomerulosclerosis (FSGS), 1 with minimal change disease (MCD), 1 with immunoglobulin A (IgA) nephropathy, 1 with class V systemic lupus erythematosus (SLE) glomerulonephritis, 1 with monoclonal diffuse proliferative glomerulonephritis, and 1 with unbiopsied nephrotic syndrome. ACTH was used as primary therapy for 3 patients; the remaining patients had previously failed a mean 2.3 immunosuppressive regimens. Eleven patients achieved a complete or partial remission, with 4 (19%) in complete remission. Of the 11 patients who achieved remission, 9 had iMN, 1 had FSGS, and 1 had IgA nephropathy. Of the 11 patients with iMN, 3 (27%) achieved complete remission and 6 (55%) achieved partial remission despite having previously failed a mean 2.4 therapies. Five patients reported steroid-like adverse effects, but there were no severe infections. The limitations were retrospective data analysis with short-term follow-up.

Conclusion:

ACTH gel may be a viable treatment option for resistant nephrotic syndrome due to membranous nephropathy. Short-term data suggest that remission rates may approach 80%.

Circulating permeability factors in idiopathic nephrotic syndrome and focal segmental glomerulosclerosis

Circulating permeability factors may be important in idiopathic nephrotic syndrome (INS) including focal segmental glomerulosclerosis (FSGS) and in recurrence after renal transplantation. Evidence for plasma factors includes posttransplant recurrence of proteinuria and its response to plasmapheresis or immunoadsorption and induction of proteinuria in experimental animals by infusion of patient plasma or its fractions. The authors and other investigators have used proteomic techniques to seek pathogenic molecules. The authors have recently proposed cardiotrophin-like cytokine-1 (CLC-1) as an active factor in FSGS. Other potential permeability factors include hemopexin and vascular permeability factor in minimal change nephrotic syndrome (MCNS) and soluble urokinase receptor in FSGS. In the authors' studies, in vitro plasma permeability activity is blocked by diverse substances that may decrease levels of active molecules or block the effects of circulating permeability factors. It has been shown that the simple sugar galactose blocks the effect of FSGS serum on albumin permeability in vitro and decreases permeability activity when administered to patients. Because identities of permeability factors and their mechanisms of action are not well defined, therapy of INS/FSGS is empiric. Corticosteroids are the mainstay of initial therapy whereas calcineurin inhibitors such as cyclosporine A (CsA) and immunosuppressive medications provide adjunctive therapy. Nonspecific therapies such as blocking the renin-angiotensin system and controlling blood pressure and plasma lipids may also diminish proteinuria and slow progression. Identification of molecules that initiate proteinuria and application of findings from in vitro studies may lead to development of new treatments to arrest progression and prevent recurrence after transplantation.