Reviews & Analysis

Intravenous fluids are widely administered to patients who have, or are at risk of, acute kidney injury (AKI), but deleterious consequences of overzealous fluid therapy are increasingly being recognized. This Review describes the problems of fluid management in acquired AKI, and discusses the need to balance the competing needs of adequate fluid resuscitation, the avoidance of progressively positive fluid balances (which can lead to extracellular volume expansion and organ edema), and the possibility of overzealous fluid removal (which can lead to hypovolemic AKI).

The selection of a specific dialysis modality can have important consequences in terms of survival and quality of life. In this Review, Lameire and Van Biesen compare the epidemiology of peritoneal dialysis with that of hemodialysis and describe some of the major differences that exist in the global utilization of these two dialysis modalities. The authors describe a number of medical and nonmedical factors, including economic, educational and psychological factors that influence dialysis modality choice.

Individuals with diabetic nephropathy experience sequential abnormalities in oxygen metabolism, partly as a result of chronic hypoxia. Toshio Miyata and Charles van Ypersele de Strihou discuss molecules involved in the defense against hypoxia, especially oxygen sensors, and novel methods of inhibiting such molecules.

Blockade of the renin–angiotensin system does not seem to prevent early nephropathy in individuals with type 1 diabetes who are normoalbuminuric and normotensive, but both the angiotensin-converting-enzyme inhibitor enalapril and the angiotensin-receptor blocker losartan seem to retard retinopathy.

The automated reporting of estimated glomerular filtration rate has increased the number of patients being referred to nephrologists, but is chronic kidney disease being incorrectly diagnosed in individuals who have normal serum creatinine levels?

Primary hyperoxaluria eventually leads to end-stage renal disease and systemic oxalosis; if left untreated, it may be fatal. The outcome might be different if primary hyperoxaluria is diagnosed early, but when is 'early'?

The degree to which systolic blood pressure should be lowered in individuals with mild hypertension is unclear. The Cardio-Sis trial has investigated whether tight systolic blood pressure control is more beneficial than usual control in individuals with hypertension but without diabetes.

Small-scale clinical trials have provided encouraging evidence on the short-term orexigenic effects of subcutaneous ghrelin administration in malnourished dialysis patients. New treatment strategies to tackle the excess mortality of this patient group are urgently needed, but the strengths, shortcomings and unanswered questions related to ghrelin treatment need to be highlighted.

This article considers the case of a 25-year-old woman with a medical history notable for joint laxity and hypermobility syndrome. She had recurrent episodes of severe, right-sided abdominal and flank discomfort, intermittent gross hematuria, and sensation of a mass on her right side. Intravenous pyelography led to a diagnosis of nephroptosis.

Chronic kidney disease (CKD) is a common condition and its prevalence is increasing. Prognosis is poor, with many patients experiencing disease progression. Recognizing the factors associated with CKD progression would enable high-risk patients to be identified and given more intensive treatment if necessary. The identification of new predictive markers might improve our understanding of the pathogenesis and progression of CKD. Here, Florian Kronenberg discusses various emerging factors and markers for which epidemiological evidence from prospective studies has shown an association with CKD progression.

Direct renin inhibition is a novel strategy for the blockade of the renin–angiotensin system. In this Review, Hollenberg discusses the evidence indicating that direct renin inhibitors might block the renin–angiotensin system in the kidney more effectively than either angiotensin-converting-enzyme inhibitors or angiotensin receptor blockers. The author also discusses the therapeutic implications of this evidence and possible mechanisms that underlie the renal effects of direct renin inhibition.

Intradialytic hypertension is not an uncommon complication in hemodialysis patients, and seems to be associated with adverse outcomes. This complex phenomenon is not well understood, and many uncertainties exist regarding its pathophysiologic mechanisms and appropriate treatment strategies. Many of the therapeutic approaches currently used come from expert recommendations rather than from the results of randomized clinical trials. In this Review, Locatelli et al. describe the possible pathophysiologic mechanisms of intradialytic hypertension, and consider potential treatment and management strategies.

A prehypertension classification of blood pressure, encompassing a blood pressure range previously regarded to be normal that has been associated with an increased risk of hypertension mortality compared with lower blood pressure, has been established. In this Review, Pimenta and Oparil discuss the epidemiology of prehypertension, the relationship with cardiovascular morbidity and mortality, and the treatment of prehypertensive patients.

Disturbances in bone metabolism are common in patients after renal transplantation and represent important causes of morbidity and mortality. This Review discusses the etiological factors that contribute to bone metabolic disturbances in renal transplant recipients—pre-existing renal osteodystrophy, the effects of transplant-specific therapies on bone metabolism, and the effects of reduced renal function after transplantation. The clinical implications of bone disease in these patients are also considered.

Induction therapy with rabbit anti-thymocyte globulin is preferable to induction with daclizumab in renal transplant recipients at high immunological risk. These findings provide additional support to the idea that personalized immunosuppressive regimens should be developed in renal transplant recipients.

In patients on hemodialysis with a history of failure to respond to hepatitis B vaccination, intradermal revaccination is more effective than repeat intramuscular vaccination. Intradermal vaccine administration might become the standard of care for high-risk patients.

Several surprising findings indicate that pharmacological blocking of the multifunctional enzyme mTOR fosters distinct differentiation programs in different immunocompetent cells. These data might lead to a striking change in our view of the role that mTOR inhibition should have in immunosuppressive therapy for allogeneic transplant recipients.

Vitamin D insufficiency is endemic amongst renal transplant recipients, as it is in other individuals with chronic diseases, both within and beyond nephrology. Few data exist to guide vitamin D replacement strategies, but indirect evidence points to likely skeletal, and possibly extraskeletal, benefits from supplementation.

In vitro evidence suggests that immune complex formation in IgA nephropathy is determined by the sugar content of the IgA1 hinge region. Absence of galactose residues in this region renders the IgA1 molecule immunogenic.

Proof has at last been provided that idiopathic membranous nephropathy is caused by autoantibodies to proteins expressed by podocytes. The discovery that autoantibodies to the M-type secretory phospholipase A2 receptor were present in most individuals affected by the condition opens a new era for the management of membranous nephropathy.