A phase 2b, randomized, double-blind, placebo-controlled, clinical trial of atacicept for treatment of IgA nephropathy.

Atacicept is a first-in-class, dual anti-B-cell Activation Factor-A Proliferation-Inducing Ligand fusion protein in clinical evaluation for treatment of IgA nephropathy. To compare efficacy and safety of atacicept versus placebo in patients with IgAN, this randomized, double-blind, placebo-controlled phase 2b clinical trial ORIGIN enrolled 116 individuals with biopsy-proven IgA nephropathy. Participants were randomized to atacicept 150, 75, or 25 mg versus placebo once weekly for up to 36 weeks. Primary and key secondary endpoints were changes in urine protein creatinine ratio based on 24-hour urine collection at weeks 24 and 36, respectively, in the combined atacicept 150 mg and 75 mg group versus placebo. The primary endpoint was met at week 24 as the mean urine protein creatinine ratio was reduced from baseline by 31% in the combined atacicept group versus 8% with placebo, resulting in a significant 25% reduction with atacicept versus placebo. At week 36, the key secondary endpoint was met as the mean urine protein creatinine ratio reduced from baseline by 34% in the combined atacicept group versus a 2% increase with placebo, resulting in a significant 35% reduction with atacicept versus placebo. The reduction in proteinuria was accompanied by stabilization in endpoint eGFR with atacicept compared to a decline with placebo at week 36, resulting in significant between-group geometric mean difference of 11%, approximating an absolute difference of 5.7 mL/min/1.73m2. Endpoint galactose deficient IgA1 levels significantly decreased from baseline by 60% versus placebo. The safety profile of atacicept was like placebo. Thus, our results provide evidence to support a pivotal, phase 3 study of atacicept in IgA nephropathy.

New therapies for immunoglobulin A nephropathy: what's the standard of care in 2023?

PURPOSE OF REVIEW: As the most common primary glomerulonephritis, immunoglobulin A (IgA) nephropathy (IgAN) is an important cause of kidney failure and mortality. Until recently, therapeutic options were limited. Fortunately, there have been numerous recent clinical trials demonstrating efficacy of new therapies in slowing chronic kidney disease (CKD) progression at varying stages of disease. RECENT FINDINGS: The TESTING trial has provided high-quality evidence for slowing estimated glomerular filtration rate (eGFR) decline with a reduced-dose glucocorticoid regimen, while demonstrating an improved safety profile. Targeted-release budesonide represents a well tolerated therapy for reducing eGFR decline. Mycophenolate mofetil may reduce CKD progression in some populations, while hydroxychloroquine is efficacious in reducing proteinuria. Sodium-glucose cotransporter (SGLT2) inhibitors and sparsentan are effective therapies for CKD due to IgAN, but should not be used in lieu of disease-modifying immunosuppressive therapy. Many new therapies are approaching readiness for clinical use. SUMMARY: Numerous therapeutic options now exist and include disease-modifying and nephroprotective drugs. Identifying the right treatment for the right patient is now the clinical challenge and, with new drugs on the horizon, represents the primary unmet research need in this rapidly-developing field.

Rituximab or cyclosporine a for the treatment of membranous nephropathy: Economic evaluation of the MENTOR trial.

BACKGROUND AND HYPOTHESIS: The MENTOR trial (MEmbranous Nephropathy Trial Of Rituximab) showed that rituximab was noninferior to cyclosporine in inducing complete or partial remission of proteinuria and was superior in maintaining proteinuria remission. However, the cost of rituximab may prohibit first-line use for some patients and health care payers. METHODS: A Markov model was used to determine the incremental cost-effectiveness ratio (ICER) of rituximab compared with cyclosporine for the treatment membranous nephropathy from the perspective of a health care payer with a life-time time horizon. The model was informed by data from the MENTOR trial where possible; additional parameters including cost and utility inputs were obtained from the literature. Sensitivity analyses were performed to evaluate the impact of reduced cost biosimilar rituximab. RESULTS: Rituximab for the treatment of membranous nephropathy was cost-effective (assuming a willingness-to-pay threshold of ${\$}$50 000 per quality adjusted life year (QALY) gained; ${\$}$US 2021) compared with cyclosporine, with an ICER of ${\$}$8 373/QALY over a lifetime time horizon. The incremental cost of rituximab therapy was ${\$}$28 007 with an additional 3.34 QALYs compared with cyclosporine. Lower cost of rituximab biosimilars resulted in a more favourable ICER, and in some cases resulted in rituximab being dominant (lower cost and great benefit) compared to cyclosporine. CONCLUSIONS: Despite the greater cost of rituximab, it may be a cost-effective option for the treatment of membranous nephropathy when compared with cyclosporine. The cost-effectiveness of rituximab is further improved with the use of less expensive biosimilars.

Mayo Clinic consensus report on membranous nephropathy: proposal for a novel classification.

Membranous nephropathy (MN) is a pattern of injury caused by autoantibodies binding to specific target antigens, with accumulation of immune complexes along the subepithelial region of glomerular basement membranes. The past 20 years have brought revolutionary advances in the understanding of MN, particularly via the discovery of novel target antigens and their respective autoantibodies. These discoveries have challenged the traditional classification of MN into primary and secondary forms. At least 14 target antigens have been identified, accounting for 80%-90% of cases of MN. Many of the forms of MN associated with these novel MN target antigens have distinctive clinical and pathologic phenotypes. The Mayo Clinic consensus report on MN proposes a 2-step classification of MN. The first step, when possible, is identification of the target antigen, based on a multistep algorithm and using a combination of serology, staining of the kidney biopsy tissue by immunofluorescence or immunohistochemistry, and/or mass spectrometry methodology. The second step is the search for a potential underlying disease or associated condition, which is particularly relevant when knowledge of the target antigen is available to direct it. The meeting acknowledges that the resources and equipment required to perform the proposed testing may not be generally available. However, the meeting consensus was that the time has come to adopt an antigen-based classification of MN because this approach will allow for accurate and specific MN diagnosis, with significant implications for patient management and targeted treatment.

An update on corticosteroid treatment for IgA nephropathy.

PURPOSE OF REVIEW: The use of corticosteroids to treat IgA nephropathy (IgAN) has been limited by many controversies related to uncertain benefit and safety concerns. Recent trials have tried to address these limitations. RECENT FINDINGS: After being paused because of an excess of adverse events in the full-dose steroid arm, the TESTING trial compared a reduced dose of methylprednisolone to placebo in patients with IgAN after optimization of supportive therapy. Steroid treatment was associated with a significant reduction in the risk of a 40% decline in estimated glomerular filtration rate (eGFR), kidney failure and kidney death as well as a sustained decrease in proteinuria compared with placebo. Serious adverse events were more frequent with the full dose regimen but less common in the reduced dose regimen. A phase III trial evaluating a new formulation of targeted-release budesonide showed a significant reduction in short-term proteinuria and has resulted in accelerated FDA approval for use in the United States. In a subgroup analysis of DAPA-CKD trial, sodium-glucose transport protein 2 inhibitors reduced the risk of kidney function decline in patients who have completed or are not eligible for immunosuppression. SUMMARY: Both reduced-dose corticosteroids and targeted-release budesonide are new therapeutic options that can be used in patients with high-risk disease. More novel-targeted therapies with a better safety profile are currently under investigations.

Incidence of and Risk Factors for Active Tuberculosis Disease in Individuals With Glomerular Disease: A Canadian Cohort Study.

RATIONALE & OBJECTIVE: Kidney failure is an established risk factor for active tuberculosis (TB) but the risk of TB has not been reported in specific kidney diseases. We sought to determine the incidence of and risk factors for active TB in patients with glomerular disease. STUDY DESIGN: Observational cohort study. SETTING & PARTICIPANTS: A provincial kidney pathology registry (2000-2012) was used to identify 3,079 adult patients with IgA nephropathy, focal segmental glomerulosclerosis (FSGS), antineutrophil cytoplasmic antibody (ANCA)-related glomerulonephritis, lupus nephritis, membranous nephropathy, minimal change disease, or "other" glomerular diseases in British Columbia, Canada. EXPOSURE: Predictors included demographics, immigration status, comorbidities, immunosuppression use, estimated glomerular filtration rate (eGFR), and proteinuria. OUTCOME: A diagnosis of active TB was ascertained using administrative data linkages and defined based on (1) the dispensation of 1 or more unique combinations of medications used to treat active TB, or (2) physician or hospital visits for active TB. ANALYTICAL APPROACH: The definition of TB was validated in an external cohort linked to the Provincial TB registry at the BC Centre for Disease Control (BCCDC). Standardized incidence ratios were calculated using the age-matched general population. Risk factors for active TB were identified using Cox proportional hazards regression analysis. RESULTS: The sensitivity and specificity of the outcome definition of active TB were 87.6% and 99.5%, respectively. During a median follow-up of 6.2 years, 41 patients developed active TB with an incidence of 197 of 100,000 person-years, approximately 23 times as high as the general population and>6 times higher than the threshold of 30 per 100,000 used to define high TB incidence. A high incidence was observed in all glomerular diseases (range, 110-403 per 100,000), in both Canadian- and foreign-born patients (range, 124-424 per 100,000), and in patients exposed or not to immunosuppression (282 vs 147 per 100,000). Factors associated with higher TB risk included immigration from a high-incidence country (HR, 3.90 [95% CI, 1.75-8.68]), diminished eGFR (HR, 2.81 [95% CI, 1.18-6.69]), higher levels of proteinuria (HR, 1.15 [95% CI, 1.04-1.27]), lupus nephritis (HR, 2.79 [95% CI, 1.37-5.68]), and immunosuppression use (HR, 2.13 [95% CI, 1.13-4.03]). LIMITATIONS: A relatively low number of events contributed to uncertainty in risk estimates. CONCLUSIONS: Patients with glomerular disease have a high incidence of active TB irrespective of disease type, demographics, or use of immunosuppression. Prospective studies are needed to evaluate the utility of screening for latent TB infection in this population. PLAIN-LANGUAGE SUMMARY: Patients with kidney failure are at high risk of developing tuberculosis (TB), a major infection that can be prevented by identifying and treating patients who have had prior exposure to TB. The risk of TB in specific kidney diseases is unknown. In this Canadian study of 3,079 patients with glomerular disease, a group of autoimmune kidney conditions, the rate of TB was 23 times higher than in the general population. The rate was high irrespective of the use of immunosuppressive drugs or whether patients had immigrated to Canada from another country. These findings suggest that screening patients with glomerular disease for prior TB exposure may be beneficial; however, this needs to be evaluated in a prospective study.

Are patients with primary glomerular disease at increased risk of malignancy?

Over the past decade, several observational studies and case series have provided evidence suggesting a connection between glomerular diseases (GN) and the development of malignancies, with an estimated risk ranging from 5%-11%. These malignancies include solid organ tumors as well as hematologic malignancies such as lymphoma and leukemia. However, these risk estimates are subject to several sources of bias, including unmeasured confounding from inadequate exploration of risk factors, inclusion of GN cases that were potentially secondary to an underlying malignancy, misclassification of GN type, and ascertainment bias arising from an increased likelihood of physician encounters compared to the general population. Consequently, population-based studies that accurately evaluate the cancer risk in GN populations are lacking. While it is speculated that long-term use of immunosuppressive medications and GN disease activity measured by proteinuria and estimated glomerular filtration rate may be associated with cancer risk in patients with GN, the independent role of these risk factors remains largely unknown. The presence of these knowledge gaps could lead to (i) lack of awareness of cancer as a potential chronic complication of GN, (ii) under-utilization of routine screening practices in clinical care that allow early diagnosis and treatment of malignancies, and (iii) under-recognition of modifiable risk factors to decrease the risk of de novo malignancies over time. This review summarizes the current evidence on the risk of cancer in patients with GN, explores the limitations of prior studies, and discusses methodological challenges and potential solutions for obtaining accurate estimates of cancer risk and identifying modifiable risk factors unique to GN populations.

A Population-Based Analysis of the Risk of Glomerular Disease Relapse after COVID-19 Vaccination.

BACKGROUND: Although case reports have described relapses of glomerular disease after COVID-19 vaccination, evidence of a true association is lacking. In this population-level analysis, we sought to determine relative and absolute risks of glomerular disease relapse after COVID-19 vaccination. METHODS: In this retrospective population-level cohort study, we used a centralized clinical and pathology registry (2000-2020) to identify 1105 adult patients in British Columbia, Canada, with biopsy-proven glomerular disease that was stable on December 14, 2020 (when COVID-19 vaccines first became available). The primary outcome was disease relapse, on the basis of changes in kidney function, proteinuria, or both. Vaccination was modeled as a 30-day time-varying exposure in extended Cox regression models, stratified on disease type. RESULTS: During 281 days of follow-up, 134 (12.1%) patients experienced a relapse. Although a first vaccine dose was not associated with relapse risk (hazard ratio [HR]=0.67; 95% confidence interval [95% CI], 0.33 to 1.36), exposure to a second or third dose was associated with a two-fold risk of relapse (HR=2.23; 95% CI, 1.06 to 4.71). The pattern of relative risk was similar across glomerular diseases. The absolute increase in 30-day relapse risk associated with a second or third vaccine dose varied from 1%-2% in ANCA-related glomerulonephritis, minimal change disease, membranous nephropathy, or FSGS to 3%-5% in IgA nephropathy or lupus nephritis. Among 24 patients experiencing a vaccine-associated relapse, 4 (17%) had a change in immunosuppression, and none required a biopsy. CONCLUSIONS: In a population-level cohort of patients with glomerular disease, a second or third dose of COVID-19 vaccine was associated with higher relative risk but low absolute increased risk of relapse.

Application of the International IgA Nephropathy Prediction Tool one or two years post-biopsy.

The International IgA Nephropathy (IgAN) Prediction Tool is the preferred method in the 2021 KDIGO guidelines to predict, at the time of kidney biopsy, the risk of a 50% drop in estimated glomerular filtration rate or kidney failure. However, it is not known if the Prediction Tool can be accurately applied after a period of observation post-biopsy. Using an international multi-ethnic derivation cohort of 2,507 adults with IgAN, we updated the Prediction Tool for use one year after biopsy, and externally validated this in a cohort of 722 adults. The original Prediction Tool applied at one-year without modification had a coefficient of variation (R2) of 55% and 54% and four-year concordance (C statistic) of 0.82 but poor calibration with under-prediction of risk (integrated calibration index (ICI) 1.54 and 2.11, with and without race, respectively). Our updated Prediction Tool had a better model fit with higher R2 (61% and 60%), significant increase in four-year C-statistic (0.87 and 0.86) and better four-year calibration with lower ICI (0.75 and 0.35). On external validation, the updated Prediction Tool had similar R2 (60% and 58%) and four-year C-statistics (both 0.85) compared to the derivation analysis, with excellent four-year calibration (ICI 0.62 and 0.56). This updated Prediction Tool had similar prediction performance when used two years after biopsy. Thus, the original Prediction Tool should be used only at the time of biopsy whereas our updated Prediction Tool can be used for risk stratification one or two years post-biopsy.

Rituximab or Cyclosporine in the Treatment of Membranous Nephropathy.

BACKGROUND: B-cell anomalies play a role in the pathogenesis of membranous nephropathy. B-cell depletion with rituximab may therefore be noninferior to treatment with cyclosporine for inducing and maintaining a complete or partial remission of proteinuria in patients with this condition. METHODS: We randomly assigned patients who had membranous nephropathy, proteinuria of at least 5 g per 24 hours, and a quantified creatinine clearance of at least 40 ml per minute per 1.73 m2 of body-surface area and had been receiving angiotensin-system blockade for at least 3 months to receive intravenous rituximab (two infusions, 1000 mg each, administered 14 days apart; repeated at 6 months in case of partial response) or oral cyclosporine (starting at a dose of 3.5 mg per kilogram of body weight per day for 12 months). Patients were followed for 24 months. The primary outcome was a composite of complete or partial remission of proteinuria at 24 months. Laboratory variables and safety were also assessed. RESULTS: A total of 130 patients underwent randomization. At 12 months, 39 of 65 patients (60%) in the rituximab group and 34 of 65 (52%) in the cyclosporine group had a complete or partial remission (risk difference, 8 percentage points; 95% confidence interval [CI], -9 to 25; P = 0.004 for noninferiority). At 24 months, 39 patients (60%) in the rituximab group and 13 (20%) in the cyclosporine group had a complete or partial remission (risk difference, 40 percentage points; 95% CI, 25 to 55; P<0.001 for both noninferiority and superiority). Among patients in remission who tested positive for anti-phospholipase A2 receptor (PLA2R) antibodies, the decline in autoantibodies to anti-PLA2R was faster and of greater magnitude and duration in the rituximab group than in the cyclosporine group. Serious adverse events occurred in 11 patients (17%) in the rituximab group and in 20 (31%) in the cyclosporine group (P = 0.06). CONCLUSIONS: Rituximab was noninferior to cyclosporine in inducing complete or partial remission of proteinuria at 12 months and was superior in maintaining proteinuria remission up to 24 months. (Funded by Genentech and the Fulk Family Foundation; MENTOR ClinicalTrials.gov number, NCT01180036.).

The Risk of Cardiovascular Events in Individuals With Primary Glomerular Diseases.

RATIONALE & OBJECTIVE: Little is known about the risk of cardiovascular disease (CVD) in patients with various primary glomerular diseases. In a population-level cohort of adults with primary glomerular disease, we sought to describe the risk of CVD compared with the general population and the impact of traditional and kidney-related risk factors on CVD risk. STUDY DESIGN: Observational cohort study. SETTING & PARTICIPANTS: Adults with membranous nephropathy (n = 387), minimal change disease (n = 226), IgA nephropathy (n = 759), and focal segmental glomerulosclerosis (n = 540) from a centralized pathology registry in British Columbia, Canada (2000-2012). EXPOSURE: Traditional CVD risk factors (diabetes, age, sex, dyslipidemia, hypertension, smoking, prior CVD) and kidney-related risk factors (type of glomerular disease, estimated glomerular filtration rate [eGFR], proteinuria). OUTCOME: A composite CVD outcome of coronary artery, cerebrovascular, and peripheral vascular events, and death due to myocardial infarction or stroke. ANALYTICAL APPROACH: Subdistribution hazards models to evaluate the outcome risk with non-CVD death treated as a competing event. Standardized incidence rates (SIR) calculated based on the age- and sex-matched general population. RESULTS: During a median 6.8 years of follow-up, 212 patients (11.1%) experienced the CVD outcome (10-year risk, 14.7% [95% CI, 12.8%-16.8%]). The incidence rate was high for the overall cohort (24.7 per 1,000 person-years) and for each disease type (range, 12.2-46.1 per 1,000 person-years), and was higher than that observed in the general population both overall (SIR, 2.46 [95% CI, 2.12-2.82]) and for each disease type (SIR range, 1.38-3.98). Disease type, baseline eGFR, and proteinuria were associated with a higher risk of CVD and, when added to a model with traditional risk factors, led to improvements in model fit (R2 of 14.3% vs 12.7%), risk discrimination (C-statistic of 0.81 vs 0.78; difference, 0.02 [95% CI, 0.01-0.04]), and continuous net reclassification improvement (0.4 [95% CI, 0.2-0.6]). LIMITATIONS: Ascertainment of outcomes and comorbidities using administrative data. CONCLUSIONS: Patients with primary glomerular disease have a high absolute risk of CVD that is approximately 2.5 times that of the general population. Consideration of eGFR, proteinuria, and type of glomerular disease may improve risk stratification of CVD risk in these individuals. PLAIN-LANGUAGE SUMMARY: Patients with chronic kidney disease are known to be at high risk of cardiovascular disease. Cardiovascular risk in patients with primary glomerular diseases is poorly understood because these conditions are rare and require a kidney biopsy for diagnosis. In this study of 1,912 Canadian patients with biopsy-proven IgA nephropathy, minimal change disease, focal segmental glomerulosclerosis, and membranous nephropathy, the rate of cardiovascular events was 2.5 times higher than in the general population and was high for each disease type. Consideration of disease type, kidney function, and proteinuria improved the prediction of cardiovascular events. In summary, our population-level study showed that patients with primary glomerular diseases have a high cardiovascular risk, and that inclusion of kidney-specific risk factors may improve risk stratification.

Effects of dapagliflozin on volume status and systemic haemodynamics in patients with chronic kidney disease without diabetes: Results from DAPASALT and DIAMOND.

AIMS: To assess the effect of sodium-glucose cotransporter-2 inhibitor dapagliflozin on natriuresis, blood pressure (BP) and volume status in patients with chronic kidney disease (CKD) without diabetes. MATERIALS AND METHODS: We performed a mechanistic open-label study (DAPASALT) to evaluate the effects of dapagliflozin on 24-hour sodium excretion, 24-hour BP, extracellular volume, and markers of volume status during a standardized sodium diet (150 mmol/d) in six patients with CKD. In parallel, in a placebo-controlled double-blind crossover trial (DIAMOND), we determined the effects of 6 weeks of dapagliflozin on markers of volume status in 53 patients with CKD. RESULTS: In DAPASALT (mean age 65 years, mean estimated glomerular filtration rate [eGFR] 39.4 mL/min/1.73 m2 , median urine albumin:creatinine ratio [UACR] 111 mg/g), dapagliflozin did not change 24-hour sodium and volume excretion during 2 weeks of treatment. Dapagliflozin was associated with a modest increase in 24-hour glucose excretion on Day 4, which persisted at Day 14 and reversed to baseline after discontinuation. Mean 24-hour systolic BP decreased by -9.3 (95% confidence interval [CI] -19.1, 0.4) mmHg after 4 days and was sustained at Day 14 and at wash-out. Renin, angiotensin II, urinary aldosterone and copeptin levels increased from baseline. In DIAMOND (mean age 51 years, mean eGFR 59.0 mL/min/1.73 m2 , median UACR 608 mg/g), compared to placebo, dapagliflozin increased plasma renin (38.5 [95% CI 7.4, 78.8]%), aldosterone (19.1 [95% CI -5.9, 50.8]%), and copeptin levels (7.3 [95% CI 0.1, 14.5] pmol/L). CONCLUSIONS: During a standardized sodium diet, dapagliflozin decreased BP but did not increase 24-hour sodium and volume excretion. The lack of increased natriuresis and diuresis may be attributed to activation of intra-renal compensatory mechanisms to prevent excessive water loss.

Quantifying Duration of Proteinuria Remission and Association with Clinical Outcome in IgA Nephropathy.

BACKGROUND: On the basis of findings of observational studies and a meta-analysis, proteinuria reduction has been proposed as a surrogate outcome in IgA nephropathy. How long a reduction in proteinuria needs to be maintained to mitigate the long-term risk of disease progression is unknown. METHODS: In this retrospective multiethnic cohort of adult patients with IgA nephropathy, we defined proteinuria remission as a ≥25% reduction in proteinuria from the peak value after biopsy, and an absolute reduction in proteinuria to <1 g/d. The exposure of interest was the total duration of first remission, treated as a time-varying covariate using longitudinal proteinuria measurements. We used time-dependent Cox proportional hazards regression models to quantify the association between the duration of remission and the primary outcome (ESKD or a 50% reduction in eGFR). RESULTS: During a median follow-up of 3.9 years, 274 of 1864 patients (14.7%) experienced the primary outcome. The relationship between duration of proteinuria remission and outcome was nonlinear. Each 3 months in sustained remission up to approximately 4 years was associated with an additional 9% reduction in the risk of disease progression (hazard ratio [HR], 0.91; 95% confidence interval [95% CI], 0.89 to 0.93). Thereafter, each additional 3 months in remission was associated with a smaller, nonsignificant risk reduction (HR, 0.99; 95% CI, 0.96 to 1.03). These findings were robust to multivariable adjustment and consistent across clinical and histologic subgroups. CONCLUSIONS: Our findings support the use of proteinuria as a surrogate outcome in IgA nephropathy, but additionally demonstrate the value of quantifying the duration of proteinuria remission when estimating the risk of hard clinical endpoints.

Effect of Oral Methylprednisolone on Decline in Kidney Function or Kidney Failure in Patients With IgA Nephropathy: The TESTING Randomized Clinical Trial.

Importance: The effect of glucocorticoids on major kidney outcomes and adverse events in IgA nephropathy has been uncertain. Objective: To evaluate the efficacy and adverse effects of methylprednisolone in patients with IgA nephropathy at high risk of kidney function decline. Design, Setting, and Participants: An international, multicenter, double-blind, randomized clinical trial that enrolled 503 participants with IgA nephropathy, proteinuria greater than or equal to 1 g per day, and estimated glomerular filtration rate (eGFR) of 20 to 120 mL/min/1.73 m2 after at least 3 months of optimized background care from 67 centers in Australia, Canada, China, India, and Malaysia between May 2012 and November 2019, with follow-up until June 2021. Interventions: Participants were randomized in a 1:1 ratio to receive oral methylprednisolone (initially 0.6-0.8 mg/kg/d, maximum 48 mg/d, weaning by 8 mg/d/mo; n = 136) or placebo (n = 126). After 262 participants were randomized, an excess of serious infections was identified, leading to dose reduction (0.4 mg/kg/d, maximum 32 mg/d, weaning by 4 mg/d/mo) and addition of antibiotic prophylaxis for pneumocystis pneumonia for subsequent participants (121 in the oral methylprednisolone group and 120 in the placebo group). Main Outcomes And Measures: The primary end point was a composite of 40% decline in eGFR, kidney failure (dialysis, transplant), or death due to kidney disease. There were 11 secondary outcomes, including kidney failure. Results: Among 503 randomized patients (mean age, 38 years; 198 [39%] women; mean eGFR, 61.5 mL/min/1.73 m2; mean proteinuria, 2.46 g/d), 493 (98%) completed the trial. Over a mean of 4.2 years of follow-up, the primary outcome occurred in 74 participants (28.8%) in the methylprednisolone group compared with 106 (43.1%) in the placebo group (hazard ratio [HR], 0.53 [95% CI, 0.39-0.72]; P < .001; absolute annual event rate difference, -4.8% per year [95% CI, -8.0% to -1.6%]). The effect on the primary outcome was seen across each dose compared with the relevant participants in the placebo group recruited to each regimen (P for heterogeneity = .11): full-dose HR, 0.58 (95% CI, 0.41-0.81); reduced-dose HR, 0.27 (95% CI, 0.11-0.65). Of the 11 prespecified secondary end points, 9 showed significant differences in favor of the intervention, including kidney failure (50 [19.5%] vs 67 [27.2%]; HR, 0.59 [95% CI, 0.40-0.87]; P = .008; annual event rate difference, -2.9% per year [95% CI, -5.4% to -0.3%]). Serious adverse events were more frequent with methylprednisolone vs placebo (28 [10.9%] vs 7 [2.8%] patients with serious adverse events), primarily with full-dose therapy compared with its matching placebo (22 [16.2%] vs 4 [3.2%]). Conclusions and Relevance: Among patients with IgA nephropathy at high risk of progression, treatment with oral methylprednisolone for 6 to 9 months, compared with placebo, significantly reduced the risk of the composite outcome of kidney function decline, kidney failure, or death due to kidney disease. However, the incidence of serious adverse events was increased with oral methylprednisolone, mainly with high-dose therapy. Trial Registration: ClinicalTrials.gov Identifier: NCT01560052.

Updating the International IgA Nephropathy Prediction Tool for use in children.

Although IgA nephropathy (IgAN) is a common cause of glomerulonephritis in children, the absence of a method to predict disease progression limits personalized risk-based treatment decisions. The adult International IgAN Prediction Tool comprises two validated Cox survival models that predict a 50% decline in estimated glomerular filtration rate (eGFR) or end stage kidney disease (ESKD) using clinical risk factors and Oxford MEST histology scores. Here, we updated the Prediction Tool for use in children using a multiethnic international cohort of 1,060 children with IgAN followed into adulthood. The updated pediatric Prediction Tool had better model fit than the original adult tool with lower Akaike Information Criterion, higher R2D and similar C-statistics. However, calibration showed very poor agreement between predicted and observed risks likely due to the observed disease trajectory in children. Therefore, the Tool was updated using a secondary outcome of a 30% reduction in eGFR or ESKD, resulting in better R2D (30.3%/22.2%) and similar C-statistics (0.74/0.68) compared to the adult tool but with good calibration. The trajectory of eGFR over time in children differed from adults being highly non-linear with an increase until 18 years old followed by a linear decline similar to that of adults. A higher predicted risk was associated with a smaller increase in eGFR followed by a more rapid decline, suggesting that children at risk of a 30% decrease in eGFR will eventually experience a larger 50% decrease in eGFR when followed into adulthood. As such, these two outcomes are analogous between pediatric and adult Prediction Tools. Thus, our pediatric Prediction Tool can accurately predict the risk of a 30% decline in eGFR or ESKD in children with IgAN.

Differential expression of microRNA miR-150-5p in IgA nephropathy as a potential mediator and marker of disease progression.

Understanding why certain patients with IgA nephropathy progress to kidney failure while others maintain normal kidney function remains a major unanswered question. To help answer this, we performed miRNome profiling by next generation sequencing of kidney biopsies in order to identify microRNAs specifically associated with the risk of IgA nephropathy progression. Following sequencing and validation in independent cohorts, four microRNAs (-150-5p, -155-5p, -146b-5p, -135a-5p) were found to be differentially expressed in IgA nephropathy progressors compared to non-progressors, and patients with thin membrane nephropathy, lupus nephritis and membranous nephropathy, and correlated with estimated glomerular filtration rate, proteinuria, and the Oxford MEST-C scores (five histological features that are independent predictors of clinical outcome). Each individual microRNA increased the discrimination score of the International IgAN Prediction Tool, although due to the small number of samples the results did not reach statistical significance. miR-150-5p exhibited the largest amplitude of expression between cohorts and displayed the best discrimination between IgA nephropathy progressors and non-progressors by receiver operating curve analysis (AUC: 0.8). However, expression was similarly upregulated in kidneys with established fibrosis and low estimated glomerular filtration rates at the time of biopsy. Consistent with a more generic role in kidney fibrosis, in situ hybridization revealed that miR-150-5p was found in lymphoid infiltrates, and areas of proliferation and fibrosis consistent with the known drivers of progression. Thus, miR-150-5p may be a potential functional mediator of kidney fibrosis that may add value in predicting risk of progression in IgA nephropathy and other kidney diseases.

Development of an international Delphi survey to establish core outcome domains for trials in adults with glomerular disease.

Outcomes relevant to treatment decision-making are inconsistently reported in trials involving glomerular disease. Here, we sought to establish a consensus-derived set of critically important outcomes designed to be reported in all future trials by using an online, international two-round Delphi survey in English. To develop this, patients with glomerular disease, caregivers and health professionals aged 18 years and older rated the importance of outcomes using a Likert scale and a Best-Worst scale. The absolute and relative importance was assessed and comments were analyzed thematically. Of 1198 participants who completed Round 1, 734 were patients/caregivers while 464 were health care professionals from 59 countries. Of 700 participants that completed Round 2, 412 were patients/caregivers and 288 were health care professionals. Need for dialysis or transplant, kidney function, death, cardiovascular disease, remission-relapse and life participation were the most important outcomes to patients/caregivers and health professionals. Patients/caregivers rated patient-reported outcomes higher while health care professionals rated hospitalization, death and remission/relapse higher. Four themes explained the reasons for their priorities: confronting death and compounded suffering, focusing on specific targets in glomerular disease, preserving meaning in life, and fostering self-management. Thus, consistent reporting of these critically important outcomes in all trials involving glomerular disease is hoped to improve patient-centered decision-making.

The Therapeutic Evaluation of Steroids in IgA Nephropathy Global (TESTING) Study: Trial Design and Baseline Characteristics.

INTRODUCTION: Despite optimal current care, up to 30% of individuals suffering from immunoglobulin A nephropathy (IgAN) will develop kidney failure requiring dialysis or kidney transplantation. The Therapeutic Evaluation of STeroids in IgA Nephropathy Global (TESTING) study was designed to assess the benefits and risks of steroids in people with IgAN. We report the trial design as well as the baseline characteristics of study participants. METHODS: It is an investigator-initiated, multicenter, double-blind, placebo-controlled, randomized trial of individuals with kidney biopsy-confirmed IgAN, proteinuria ≥1 g/day, and an estimated GFR of 20-120 mL/min/1.73 m2, following at least 3 months of standard of care including maximum labelled (or tolerated) dose of renin-angiotensin system blockade. The original study design randomized participants 1:1 to oral methylprednisolone (0.6-0.8 mg/kg/day, maximum 48 mg/day) for 2 months, with subsequent weaning by 8 mg/day/month over 6-8 months, or matching placebo. The intervention was modified in 2016 (due to an excess of serious infection) to low-dose methylprednisolone (0.4 mg/kg/day, maximum 32 mg/day) for 2 months, followed by weaning by 4 mg/day/month over 6-9 months, or matching placebo. Participants recruited after 2016 also received prophylaxis against Pneumocystis jirovecii pneumonia during the first 12 weeks of treatment. RESULTS: The study recruitment period extended from May 2012 to November 2019. By the time the excess of serious infections was observed, 262 participants had been randomized to the original full-dose treatment algorithm, and an interim analysis was reported in 2016. Subsequently, 241 additional participants were randomized to a revised low-dose protocol, for a total of 503 participants from China (373), India (78), Canada (24), Australia (18), and Malaysia (10). The mean age of randomized participants was 38, 39% were female, mean eGFR at randomization was 62.7 mL/min/1.73 m2, and mean 24-h urine protein 2.54 g. The primary endpoint is a composite of 40% eGFR decline from baseline or kidney failure (dialysis, transplantation, or death due to kidney disease), and participants will be followed until the primary outcome has been observed in at least 160 randomized participants. Analyses will also be made across predefined subgroups. Effects on eGFR slope and albuminuria will also be assessed overall, as well as by the steroid dosing regimen. CONCLUSIONS: The TESTING study (combined full and low dose) will define the benefits of corticosteroid use on major kidney outcomes, as well as the risks of therapy, and provide data on the relative effects of different doses, in individuals with high-risk IgAN.

Coding practice in national and regional kidney biopsy registries.

BACKGROUND: Kidney biopsy registries all over the world benefit research, teaching and health policy. Comparison, aggregation and exchange of data is however greatly dependent on how registration and coding of kidney biopsy diagnoses are performed. This paper gives an overview over kidney biopsy registries, explores how these registries code kidney disease and identifies needs for improvement of coding practice. METHODS: A literature search was undertaken to identify biopsy registries for medical kidney diseases. These data were supplemented with information from personal contacts and from registry websites. A questionnaire was sent to all identified registries, investigating age of registries, scope, method of coding, possible mapping to international terminologies as well as self-reported problems and suggestions for improvement. RESULTS: Sixteen regional or national kidney biopsy registries were identified, of which 11 were older than 10 years. Most registries were located either in Europe (10/16) or in Asia (4/16). Registries most often use a proprietary coding system (12/16). Only a few of these coding systems were mapped to SNOMED CT (1), older SNOMED versions (2) or ERA-EDTA PRD (3). Lack of maintenance and updates of the coding system was the most commonly reported problem. CONCLUSIONS: There were large gaps in the global coverage of kidney biopsy registries. Limited use of international coding systems among existing registries hampers interoperability and exchange of data. The study underlines that the use of a common and uniform coding system is necessary to fully realize the potential of kidney biopsy registries.

Improving treatment decisions using personalized risk assessment from the International IgA Nephropathy Prediction Tool.

Immunosuppression in IgA nephropathy (IgAN) should be reserved for patients at high-risk of disease progression, which KDIGO guidelines determine based solely on proteinuria 1g or more/day. To investigate if treatment decisions can be more accurately accomplished using individualized risk from the International IgAN Prediction Tool, we simulated allocation of a hypothetical immunosuppression therapy in an international cohort of adults with IgAN. Two decision rules for treatment were applied based on proteinuria of 1g or more/day or predicted risk from the Prediction Tool above a threshold probability. An appropriate decision was defined as immunosuppression allocated to patients experiencing the primary outcome (50% decline in eGFR or ESKD) and withheld otherwise. The net benefit and net reduction in treatment are the proportion of patients appropriately allocated to receive or withhold immunosuppression, adjusted for the harm from inappropriate decisions, calculated for all threshold probabilities from 0-100%. Of 3299 patients followed for 5.1 years, 522 (15.8%) experienced the primary outcome. Treatment allocation based solely on proteinuria of 1g or more/day had a negative net benefit (was harmful) because immunosuppression was increasingly allocated to patients without progressive disease. Compared to using proteinuria, treatment allocation using the Prediction Tool had a larger net benefit up to 23.4% (95% confidence interval 21.5-25.2%) and a larger net reduction in treatment up to 35.1% (32.3-37.8%). Thus, allocation of immunosuppression to high-risk patients with IgAN can be substantially improved using the Prediction Tool compared to using proteinuria.