News & Views in 2013

In a meta-analysis of randomized trials, de Borst and colleagues report that vitamin D therapy reduces proteinuria and might also slow the progression of chronic kidney disease. In light of the limited options for renoprotective therapy, we evaluate whether this evidence for vitamin D treatment justifies a large, definitive trial.

Two trials of low-glucose-containing peritoneal dialysis regimen in patients with diabetes mellitus show that although this strategy improved glycaemic control, it was associated with increased risk of serious adverse events and mortality. These studies suggest caution is needed when evaluating effectiveness using surrogate measures and awareness of confounding factors is important.

Renal biopsy is the gold standard for detection of rejection in kidney transplant recipients, but is not considered until evidence of renal dysfunction is apparent. Now, Suthanthiran and colleagues suggest that mRNA levels in urinary cells from these patients might be diagnostic and prognostic of acute cellular rejection.

Follow-up data from the RAVE trial have shown that rituximab is as effective as immunosuppression with cyclophosphamide followed by azathioprine in antineutrophil cytoplasmic antibody (ANCA) associated vasculitis. Rituximab is likely to become the standard of care for many patients with ANCA disease. However, an individualized approach is needed to identify those who require more-intense or prolonged therapy.

Current guidelines recommend lowering blood pressure (BP) in patients with chronic kidney disease and hypertension. However, a new study suggests that achieving ideal systolic BP targets at the expense of low diastolic BP <70 mmHg is not advantageous for outcomes.

A new study provides cogent evidence that fluid overload—measured using bioimpedance spectroscopy—promotes progression of chronic kidney disease (CKD). A prospective randomized trial is warranted to assess the effect of interventions to reduce fluid overload on disease progression in patients with CKD.

Accurate stratification of renal risk is important for the effective management of patients with type 2 diabetes. In a new study, Elley et al. report and validate a 5-year prediction model for the development of end-stage renal disease in patients with type 2 diabetes in primary care.

Multiple interventions can retard the progression or prevent the development of microvascular and macrovascular complications in patients with diabetes, but the effects of early glycaemic control seem to be longer lasting than those of blood pressure control. Cherney et al. now report that renin–angiotensin system blockade has sustained beneficial effects in patients with type 1 diabetes mellitus.

A new study by Turin et al. reports that proteinuria of increasing severity is associated with a faster rate of decline in estimated glomerular filtration rate (eGFR), regardless of eGFR at baseline. These findings support the use of proteinuria testing to identify individuals at risk of chronic kidney disease progression.

A new meta-analysis reports that intensive blood pressure lowering reduces the risk of kidney failure in patients with chronic kidney disease and albuminuria. However, the level of blood pressure control required for optimum protection of the cardiovascular and renal systems remains unclear.

Ralib et al. report that urine output (UO) <0.3 ml/kg/h for >6 h predicts a composite outcome of mortality and dialysis requirement in critically ill patients. Their findings validate UO as a marker of acute kidney injury, but raise the question of whether the diagnostic thresholds should be more stringent.

New data suggest that arteriovenous fistulas compared with prosthetic grafts may not be a superior predialysis approach to vascular access for haemodialysis in patients aged ≥80 years. However, the use of catheters as the first vascular access was associated with significantly increased mortality in these patients and should be avoided.

Renal fibrosis and anaemia are hallmarks of progressive chronic kidney disease (CKD). New evidence demonstrates that these conditions are intimately connected, as injury triggers the phenotypic transition of renal erythropoietin-producing cells into fibrogenic myofibroblasts. Strategies to reverse such a transition may hold promise to alleviate both anaemia and fibrosis in CKD.

An epidemic of chronic kidney disease of unknown aetiology has emerged in Central America and resulted in the highest rates of end-stage renal disease worldwide. New findings from the first renal biopsy study of patients with Mesoamerican nephropathy should help medical detectives to 'crack' the cause of this disease.

Ezzelarab et al. report that regulatory dendritic cells administered prior to transplantation modulate alloimmunity and increase kidney allograft survival. This finding provides the first evidence of the immunosuppressive efficacy of modified dendritic cells in a stringent pre-clinical primate model, offering hope that long-term immunosuppression of transplant recipients could be minimized or avoided.

Ravani et al. report that rituximab is a safe and effective steroid-sparing and calcineurin-inhibitor-sparing agent in 46 children with idiopathic nephrotic syndrome over a median follow-up of 3 years. What is the risk-to-benefit profile of rituximab compared to that of the other available drugs for treating this disease?

The optimal dialysate bicarbonate concentration is one that prevents acidosis at the beginning of the next dialysis session while avoiding postdialysis alkalosis. Few studies have assessed the effect of different dialysate bicarbonate levels on patient outcomes, but Tentori et al. now report that high dialysate bicarbonate concentrations may contribute to adverse outcomes.

Caroli et al. recently used a haemodynamic computational model to simulate changes in vessel dimensions and blood flow volumes in response to arteriovenous fistula (AVF) creation. This study has provided new insights into the use of preoperative ultrasound to identify sites for AVF creation and reduce rates of fistula nonmaturation.

Effective treatments for atypical haemolytic uraemic syndrome (aHUS) have long been lacking, but the discovery that complement dysregulation is a major risk factor for this disease and the availability of the complement inhibitor eculizumab have improved the clinical picture. Legendre et al. have now published results from two prospective trials investigating eculizumab use in aHUS. Although we have come a long way, questions remain.

Whether use of non-calcium-containing phosphate binders versus calcium-containing phosphate binders improves outcomes for patients with chronic kidney disease is unclear. Now, new data from an open-label randomized controlled trial suggest that the non-calcium-containing phosphate binder sevelamer hydrochloride significantly improves survival compared to calcium carbonate in incident patients on haemodialysis.