Reviews & Analysis

Studies of kidney function after orthotopic liver transplantation have yielded conflicting results, and there is a paucity of data on renal outcomes after combined liver–kidney transplantation. In this Review, authors from the University of California, Los Angeles attempt to synthesize the available findings into a cohesive update. Focus is given to the effect of the introduction of the MELD scoring system.

Although cardiovascular disease is the most common cause of death among people with chronic renal dysfunction, conventional cardiovascular risk factors are paradoxically associated with improved survival in hemodialysis populations. Here, the authors analyze emerging data that support this 'reverse epidemiology'. Confirmation of this phenomenon might lead to the formulation of more effective management strategies, tailored to patient characteristics and disease stage.

The authors provide a brief overview of the physiological and pharmacological relevance of proteins that translocate organic anions. Focusing on OATs located in the basolateral membrane of proximal tubule cells, the authors discuss data fromXenopusoocytes and knockout mice. The potential for new findings to shed light on an individual patient's response to treatment with a particular drug, and the risks of toxic effects, are emphasized.

Elucidating the mechanisms that contribute to disease development often requires experiments that are difficult to perform in patients. Mutant mice that recapitulate the characteristics of the X-linked disorder Dent disease have proved to be useful experimental surrogates. Here, an investigator involved in development of one of these mouse models summarizes the most clinically relevant data that have been generated to date.

The Acute Kidney Injury Network (AKIN) met in Amsterdam, The Netherlands, in September 2005. At the 2-day meeting, participants in this multidisciplinary collaboration proposed a standard definition, and scheme for the classification, of AKI. Widespread adoption of these standards, presented here by members of the AKIN working group, would help to advance the study of this condition, and improve patient outcomes.

The Appropriate Blood Pressure Control in Diabetes (ABCD) study remains one of the most relevant sources of data on the vexed issue of optimum management of blood pressure in diabetic patients. This Review by trial investigators provides a more-comprehensive description of data that have emerged from this 5-year, randomized study of moderate versus intensive control of blood pressure using either a calcium channel blocker or an ACE inhibitor.

Since the first successful transplantations were performed around 50 years ago, the lack of improvement in long-term graft survival and the risks associated with immunosuppressive therapy have made the ability to induce tolerance a burning desire among transplantation immunobiologists. These authors outline the considerable challenges that stand in the way of this goal, and proffer their opinion on which strategies are most likely to succeed.

The authors analyze experimental findings which indicate that limiting protein intake protects the kidney and ameliorates uremic symptoms, outline how the body adapts to reduced protein intake, and describe the metabolic benefits for people with chronic kidney disease. Data from randomized controlled trials and meta-analyses pertaining to the effects of low-protein diets in this population are reviewed.

Hospitalized patients have several stimuli for vasopressin production that increase the risk of their serum sodium concentration dropping to dangerous levels. Here, Moritz and Ayus elegantly present evidence to support their opinion that prevention and management of hyponatremia are worryingly inadequate in many institutions. They assert that fundamental changes to long-standing, but erroneous, tenets of fluid therapy are needed to prevent unnecessary deaths.

Earlier this year, the FDA responded to the findings of CHOIR and several other studies by issuing a Public Health Advisory about the risks associated with erythropoiesis-stimulating agents, and introducing a black box warning to the labeling of these drugs. In this Viewpoint, Ajay K Singh responds to some of the criticisms that have been leveled at CHOIR and offers some practical advice for implementing the FDA's guidance.

A group chaired by a rheumatologist recently published a consensus document inArthritis and Rheumatismthat codified definitions of renal responses and non-responses to therapy in patients with lupus nephritis. In this Viewpoint, the co-director of a renal-rheumatology lupus clinic argues that nephrologists have a key role to play in the diagnosis and treatment of lupus nephritis, and that they should not allow rheumatologists to take over the management of this condition.

A group from Technion, Israel, presents data to support an association between diabetic complications and the pattern of inheritance of alleles for the hemoglobin-binding protein haptoglobin. Experimental and preliminary clinical evidence indicate that the antioxidant protection conferred by haptoglobin is dependent upon genotype. Confirmation of the hypothesis will provide the rationale for trials of genotype-guided antioxidant therapies in diabetic populations.

Unfortunately, dialysis and kidney transplantation do not always ameliorate the retarded growth that is a feature of pediatric end-stage renal disease. This discussion encompasses the main factors that affect the growth of children after transplantation, including age at transplantation, function of the grafted kidney and use of corticosteroids. Evidence for and against the use of recombinant human growth hormone in this patient population is presented.

The authors present the latest evidence supporting genetic contributions to IgA nephropathy, a common form of primary glomerulonephritis throughout the world. No specific causative gene has yet been detected, but defective glycosylation of IgA1 leading to formation of immune complexes has been consistently implicated. The prevalence of familial forms of the condition varies depending on geography and ethnicity. The clinical patterns of these under-recognized familial forms are reviewed here.

For clinicians treating chronic conditions such as end-stage renal disease (ESRD), the quality of patients' lives is an important consideration. This Viewpoint highlights the ways in which health-related quality of life can be measured in ESRD (e.g. with generic instruments that facilitate comparisons with the general population and between countries), and the difficulties of such measurement. The authors offer their suggestions of how best to obtain and use this information to improve the care and outcomes of patients with ESRD.

In formulating a clear and succinct answer to the question posed by this Viewpoint, the authors highlight several important considerations. They discuss how the choice of induction agent, the presence of risk factors for relapse and the definition of remission can influence the timing of the switch to maintenance therapy and/or the duration of maintenance treatment in patients with ANCA-associated vasculitis.