Reviews & Analysis

The authors proffer their response to the question previously posed by Joanne Bargman inNature Clinical Practice Nephrology: “Why are rheumatologists treating lupus nephritis?” They argue that rheumatologists are often the first point of call for patients presenting with systemic lupus erythematosus, and that they are also more adept than nephrologists at assessing certain extrarenal manifestations of the disease. Thus, the rheumatologist is ideally placed to design and monitor treatment, with the aid of a nephrologist.

Tuberculosis is a serious opportunistic infection in renal transplant recipients. Post-transplantation tuberculosis most commonly occurs within the first few years of receipt of a renal allograft, but Ram et al. present the case of a 27-year-old male who presented with isolated skin ulcers caused by Mycobacterium tuberculosis 12 years after kidney transplantation. They review the literature on post-transplantation tuberculosis and discuss treatment options.

There are several renal syndromes that are unique to patients with cancer, being caused either by the cancer itself or by its treatment. This Review provides nephrologists—who are essential members of the multidisciplinary team that cares for patients with malignancy—with an overview of these syndromes. The article is divided into sections that deal with the renal impact of different cancer types, interventions, and commonly used chemotherapeutic and biological agents.

Until recently gadolinium chelates were thought to be safe when used as contrast agents for MRI. These compounds are now known to be associated with artifactual results of laboratory tests, acute kidney injury and nephrogenic systemic fibrosis, complications that seem to exclusively affect people with impaired renal function. Penfield and Reilly provide the information that physicians need to determine the relative risks and benefits of administering gadolinium to patients with chronic kidney disease.

The difficulties that are inherent in the differential diagnosis of hemolytic uremic syndrome and thrombotic thrombocytopenic purpura are a function of the overlap in presenting features. The authors of this Review assert that patient management could be more usefully directed by basing diagnosis on recently elucidated pathogenic mechanisms. To that end, they discuss the involvement of deficiencies in metalloprotease ADAMTS13, and dysfunctional complement proteins.

Screening for chronic kidney disease in patients with diabetes should encompass not only testing for albuminuria, but also the subsequent diagnostic procedures and interventions. Otherwise, what is the purpose of testing? The authors of this Viewpoint highlight the inadequacies of current screening practices, and argue that detection of increased urinary albumin excretion in a patient with diabetes should be a call to action.

Acute renal infarction (ARI) is a rare disease that is often misdiagnosed initially because of its nonspecific presentation. In this Case Study, Nasser and colleagues describe a patient with ARI due to a thromboembolism from a cardiac thrombus. They discuss the common presenting symptoms of ARI and comment on the various treatment options that are available.

Members of the WNK family of novel serine/threonine kinases inhibit secretion of potassium from the kidney via ROMK. Potassium deficiency—a common problem of modern diets—promotes potassium retention by upregulating WNK1. In this Review of data from animal and human studies, Huang and Kuo frame the hypothesis that WNK-mediated potassium retention is accompanied by sodium retention, and thereby contributes to the development of salt-sensitive hypertension.

It is important that care providers recognize that increased blood pressure during gestation increases a woman's chances of developing cardiovascular problems later in life. To that end, authors from the Mayo Clinic have brought together data that support this association. As we lack large-scale studies of prevention strategies, Garovic and Hayman recommend that women who have had hypertensive pregnancies should be carefully monitored after pregnancy for risk factors associated with cardiovascular disease.

The bio-incompatible characteristics of standard peritoneal dialysis solutions, such as high glucose concentration and nonphysiologic pH, have spurred the development of a new generation of more-biocompatible solutions. In this overview of available clinical data, the advantages and drawbacks of using fluids that contain amino acids or icodextrin, or that have a neutral pH, are debated. The authors conclude that the new peritoneal dialysis solutions hold great promise for improving ultrafiltration and clinical outcomes.

Since the publication of the CHOIR and CREATE study results, tremendous attention has focused on the cardiovascular effects of anemia correction in patients with chronic kidney disease. Less publicized has been the finding of a potentially higher risk of progression to end-stage renal disease among patients assigned to a higher hemoglobin target. Ajay K Singh examines whether the sum of evidence indicates a harmful or a beneficial effect of anemia correction on the progression of kidney disease.

In the second of two opposing Viewpoints, these authors from the Greenslopes and Princess Alexandra Hospital Hypertension Units in Brisbane, Australia, describe why, who, and how they screen for primary aldosteronism. They argue that diagnosing (using a stepwise selective approach) and curing or specifically treating aldosterone excess is good for the patient and inexpensive compared with potentially lifelong and less-effective nonspecific antihypertensive therapy.

This, the first of two opposing Viewpoints, sets out the arguments against screening for primary aldosteronism. The author, from the Western General Hospital in Edinburgh, UK, asserts that the majority of individuals with a high aldosterone:renin ratio have a normal plasma aldosterone level. Physicians should, therefore, focus on optimizing the excretion of salt and water in hypertensive patients rather than on expensive tests to detect an aldosterone-secreting adenoma.

There is currently insufficient evidence to recommend screening of kidney allograft donors and recipients for parvovirus B19 infection. As such, physicians managing recipients need to have a high index of suspicion, and include this type of infection in their differential diagnosis of chronic anemia and other cytopenias in the post-transplantation period. Here, Waldman and Kopp from the NIH review the pathogenesis, diagnosis and management of parvovirus B19 infection.

This wide-ranging introduction to new technologies for the management of renal failure touches on the optimization of conventional dialysis and on alternative techniques such as transplantation methods, artificial kidneys, tissue engineering strategies and harnessing the regenerative capacity of stem cells. The potential for other organs to 'host' renal functions, and the co-opting of developmental plasticity, are also discussed.

Vesicoureteral reflux is a prevalent disease commonly encountered by primary pediatricians, pediatric nephrologists and pediatric urologists. Few issues in pediatrics generate as much controversy as the management of this condition. Different treatment options, as well as pathophysiology, clinical presentation and initial work-up, and radiographic assessment, are discussed here by two urological and surgical specialists.

This Viewpoint puts forward the intriguing hypothesis that vitamin K is a modifiable risk factor for vascular calcification in patients on dialysis. Reports linking vitamin K with regulation of vascular calcification via the actions of matrix GLA protein are set in the context of the authors' own data on the incidence of subclinical vitamin K deficiency and the use of the vitamin K antagonist warfarin in the dialysis setting.

Bomback and Klemmer have systematically reviewed the literature on aldosterone breakthrough in people treated with angiotensin-converting-enzyme inhibitors and angiotensin-receptor blockers. Although the data are not yet supportive of widespread screening of asymptomatic patients, the authors contend that physicians should test for this phenomenon in selected patients and consider initiating treatment with aldosterone antagonists or renin inhibitors.