Effects of rare kidney diseases on kidney failure: a longitudinal analysis of the UK National Registry of Rare Kidney Diseases (RaDaR) cohort

Sodium-glucose cotransporter-2 (SGLT-2) inhibitors for adults with chronic kidney disease: a clinical practice guideline

CLINICAL QUESTION

What is the impact of sodium-glucose cotransporter-2 (SGLT-2) inhibitors on survival and on cardiovascular and kidneyoutcomes for adults living with chronic kidney disease (CKD)?

CURRENT PRACTICE

Few therapies slow kidney disease progression and improve long term prognosis for adults living with CKD. SGLT-2 inhibitors have demonstrated cardiovascular and kidney benefits in adults with CKD with and without type 2 diabetes. Existing guidance for SGLT-2 inhibitors does not account for the totality of current best evidence for adults with CKD and does not provide fully stratified treatment effects and recommendations across all risk groups based on risk of CKD progression and complications.

RECOMMENDATIONS

The guideline panel considered evidence regarding benefits and harms of SGLT-2 inhibitor therapy for adults with CKD over a five year period, along with contextual factors, and provided the following recommendations:1. For adults at low risk of CKD progression and complications, we suggest administering SGLT-2 inhibitors (weak recommendation in favour)2. For adults at moderate risk of CKD progression and complications, we suggest administering SGLT-2 inhibitors (weak recommendation in favour)3. For adults at high risk of CKD progression and complications, we recommend administering SGLT-2 inhibitors (strong recommendation in favour)4. For adults at very high risk of CKD progression and complications, we recommend administering SGLT-2 inhibitors (strong recommendation in favour).Recommendations are applicable to all adults with CKD, irrespective of type 2 diabetes status.

HOW THIS GUIDELINE WAS CREATED

An international panel including patients, clinicians, and methodologists produced these recommendations following standards for trustworthy guidelines and using the GRADE approach. The panel identified typical risk strata of adults with CKD (from low to very high risk of CKD progression and related complications) using the classification system developed by Kidney Disease Improving Global Outcomes (KDIGO), and applied an individual patient perspective in moving from evidence to recommendations. Effects of SGLT-2 inhibitors were interpreted in absolute terms applicable to different risk strata with varying baseline risks for outcomes of benefit over a five year period. The panel explicitly considered the balance of benefits, harms, and burdens of starting an SGLT-2 inhibitor, incorporating the values and preferences of adults with different risk profiles. Interactive evidence summaries and decision aids accompany multilayered recommendations, developed in an online authoring and publication platform (www.magicapp.org) that allows reuse and adaptation.

THE EVIDENCE

A linked systematic review and pairwise meta-analysis (13 trials including 29 614 participants) of benefits and harms associated with SGLT-2 inhibitors in adults with CKD with or without type 2 diabetes informed guidance. Among individuals at very high risk of CKD progression and complications, moderate to high certainty evidence shows SGLT-2 inhibitors (relative to placebo or standard care without SGLT-2 inhibitors) decrease all-cause and cardiovascular mortality, hospitalisation for heart failure, kidney failure, non-fatal myocardial infarction, and non-fatal stroke. Among individuals at high risk, moderate to high certainty evidence shows SGLT-2 inhibitors result in similar benefits across outcomes except demonstrating little or no effect on hospitalisation for heart failure and kidney failure. Among individuals at moderate and low risk, moderate to high certainty evidence shows SGLT-2 inhibitors probably reduce all-cause mortality and non-fatal stroke, with little or no effect for other outcomes of benefit. Risk-stratified estimates were unavailable for outcomes of harm; the panel therefore considered absolute effects summarised across risk strata. SGLT-2 inhibitors are associated with little or no effect on acute kidney injury requiring dialysis, bone fractures, lower limb amputations, ketoacidosis, genital infections, or symptomatic hypovolaemia, although a residual possibility of harms at the individual patient level remains.

UNDERSTANDING THE RECOMMENDATION

In order to apply recommendations, clinicians must appropriately identify adults with CKD, consider the underlying aetiology, and risk stratify them based on glomerular filtration rate (estimated or measured) and degree of albuminuria. In addition to classifying individuals into risk strata, further estimation of a given patient's risk based on the extent of their kidney disease and other comorbidities may be warranted to inform individual-level decisions and shared decision making. Available risk calculators may help estimate a given patient's risk of CKD progression and complications.

Cardiovascular and non-renal complications of chronic kidney disease: Managing risk

Chronic kidney disease (CKD) currently affects approximately 850 million people globally and is continuing to increase in prevalence as well as in importance as a cause of death. The excess mortality related to CKD is mostly caused by an increase in cardiovascular disease. This includes atherosclerotic cardiovascular disease as many promoters of atherosclerosis, such as blood pressure, lipid levels and hypercoagulation, are increased in people with CKD. Diabetes is a leading cause of CKD contributing to the risk of CVD, and obesity is also increasingly prevalent. Management of these risk factors is therefore very important in CKD, and to reduce risk of CKD progression. Heart failure is also more prevalent in CKD and, again, many risk factors are shared. The concept of foundational pillars in the management of heart failure has been adapted to the treatment of CKD, with many organ-protective interventions, such renin-angiotensin system blockade, sodium-glucose cotransporter-2 inhibition and mineralocorticoid receptor antagonism, reducing the risk for mortality in heart failure with reduced ejection fraction, but also for progression of CKD. Atrial fibrillation is also more common with CKD and affects the management of the former. In this review these non-renal complications of CKD are discussed, along with how the risk of these complications should be managed. Many new opportunities have demonstrated heart and kidney organ protection, but implementation is a challenge.

Description and Cross-Sectional Analyses of 25,880 Adults and Children in the UK National Registry of Rare Kidney Diseases Cohort

Introduction

The National Registry of Rare Kidney Diseases (RaDaR) collects data from people living with rare kidney diseases across the UK, and is the world's largest, rare kidney disease registry. We present the clinical demographics and renal function of 25,880 prevalent patients and sought evidence of bias in recruitment to RaDaR.

Methods

RaDaR is linked with the UK Renal Registry (UKRR, with which all UK patients receiving kidney replacement therapy [KRT] are registered). We assessed ethnicity and socioeconomic status in the following: (i) prevalent RaDaR patients receiving KRT compared with patients with eligible rare disease diagnoses receiving KRT in the UKRR, (ii) patients recruited to RaDaR compared with all eligible unrecruited patients at 2 renal centers, and (iii) the age-stratified ethnicity distribution of RaDaR patients with autosomal dominant polycystic kidney disease (ADPKD) was compared to that of the English census.

Results

We found evidence of disparities in ethnicity and social deprivation in recruitment to RaDaR; however, these were not consistent across comparisons. Compared with either adults recruited to RaDaR or the English population, children recruited to RaDaR were more likely to be of Asian ethnicity (17.3% vs. 7.5%, P-value < 0.0001) and live in more socially deprived areas (30.3% vs. 17.3% in the most deprived Index of Multiple Deprivation (IMD) quintile, P-value < 0.0001).

Conclusion

We observed no evidence of systematic biases in recruitment of patients into RaDaR; however, the data provide empirical evidence of negative economic and social consequences (across all ethnicities) experienced by families with children affected by rare kidney diseases.

Developing Therapies for C3 Glomerulopathy: Report of the Kidney Health Initiative C3 Glomerulopathy Trial Endpoints Work Group

Randomized clinical trials are underway to evaluate the efficacy of novel agents targeting the alternative complement pathway in patients with C3 glomerulopathy (C3G), a rare glomerular disease. The Kidney Health Initiative convened a panel of experts in C3G to ( 1 ) assess the data supporting the use of the prespecified trial end points as measures of clinical benefit and ( 2 ) opine on efficacy findings they would consider compelling as treatment(s) of C3G in native kidneys. Two subpanels of the C3G Trial Endpoints Work Group reviewed the available evidence and uncertainties for the association between the three prespecified end points-( 1 ) proteinuria, ( 2 ) eGFR, and ( 3 ) histopathology-and anticipated outcomes. The full work group provided feedback on the summaries provided by the subpanels and on what potential treatment effects on the proposed end points they would consider compelling to support evidence of an investigational product's effectiveness for treating C3G. Members of the full work group agreed with the characterization of the data, evidence, and uncertainties, supporting the end points. Given the limitations of the available data, the work group was unable to define a minimum threshold for change in any of the end points that might be considered clinically meaningful. The work group concluded that a favorable treatment effect on all three end points would provide convincing evidence of efficacy in the setting of a therapy that targeted the complement pathway. A therapy might be considered effective in the absence of complete alignment in all three end points if there was meaningful lowering of proteinuria and stabilization or improvement in eGFR. The panel unanimously supported efforts to foster data sharing between academic and industry partners to address the gaps in the current knowledge identified by the review of the end points in the aforementioned trials.