Viewpoint in 2006

Renal pathological changes seen in individuals with the zoonotic disease leptospirosis include interstitial nephritis and tubular necrosis. With a particular emphasis on the role of hemodynamics, this author from Thailand examines the pathogenesis of renal dysfunction in leptospirosis. The utility of dopamine in this setting is contrasted with its effects in renal dysfunction of other etiologies.

The Iranian model of kidney transplantation, whereby donors are paid by a government-sponsored agency, has eliminated the waiting list completely. Elsewhere, black markets for kidneys encourage exploitation of the poor and harm both donors and recipients. As the buying and selling of organs increases relentlessly despite legislation, this author argues that failure to regulate these practices could be considered unethical.

These authors present their controversial opinion that the evidence for a specific renoprotective effect of renin–angiotensin blockade, independent of blood-pressure control, is more ambiguous and the magnitude of any such effect much smaller than is often claimed. Data from several large trials of renin–angiotensin blockers and elegant renal cross-transplantation experiments in mice are proffered in support of their theory.

Could the shortage of transplantable kidneys in the developed world be reduced by allowing willing individuals to sell their organs? To answer this question, the authors examine the outcomes of patients who have received paid kidneys, and the financial compensation and postoperative care received by their donors. Adoption of commercial kidney transplantation in the Western world would have inevitable knock-on effects in developing countries, they argue.

By reducing the plasma concentration of nephrotoxic myeloma paraproteins, plasmapheresis could promote recovery of renal function and lessen the need for chronic dialysis in patients with myeloma cast nephropathy. Weighing up the findings and limitations of the three randomized controlled trials of plasmapheresis conducted to date in myeloma cast nephropathy, the author considers whether there is, or might be in future, a place for it in this setting.

Progressive renal fibrosis is characteristic of all the diseases that cause renal failure. Although this process is invariably associated with leukocyte infiltration, the extent to which it is controlled by these infiltrating cells is unclear. Corralling data on the roles of macrophages in progressive renal scarring, Andrew J Rees considers whether leukocyte infiltration could be successfully harnessed as a therapeutic target in this setting.

Even advanced sclerotic glomeruli show ongoing cell turnover, indicating that there is potential for modulation of the progressive renal scarring seen in chronic kidney disease. Agnes Fogo examines the mechanisms of glomerulosclerosis, with a particular focus on the pivotal role of angiotensin, and considers the potential reversibility of the processes involved.

Jörg Radermacher argues that although renal resistive index is not a perfect test for renovascular disease or ischemic nephropathy, it can provide useful diagnostic information in both of these settings. The author examines the utility of renal resistive index measurements in the diagnosis of renal artery stenosis, ischemic nephropathy and hypertensive nephrosclerosis.

Selective cyclo-oxygenase 2 inhibitors (coxibs) were designed to provide effective analgesia without the gastrointestinal toxicity of classical, nonselective nonsteroidal anti-inflammatory drugs (NSAIDs). Concern has arisen, however, about the cardiovascular and renal safety of coxibs. In this Viewpoint, Matthias Hermann and Thomas F Lüscher examine the differences among these agents in their effects on sodium excretion, glomerular filtration rate and blood pressure, and provide their overall recommendation for use of these agents.

Although renal dysfunction can have a profound effect on the pathogenesis of cardiovascular disease, current guidelines for the management of hyperlipidemia in patients with chronic kidney disease (CKD) were formulated in the absence of data on cardiovascular and cerebrovascular outcomes in this population. Considering the individual stages of CKD, authors from the University of Würzburg, Germany, analyze data from the 4D trial and other studies, and attempt to answer the question of when hyperlipidemia should (or should not) be treated in patients with CKD.

Terry Strom and Manikkam Suthanthiran present the results of studies investigating the potential of transcriptional profiling, based on both polymerase chain reaction and DNA array technologies, to identify renal allograft rejection from allograft biopsy specimens, blood and urine sediment. They argue that in future, such analysis will function not only as a surrogate for the invasive biopsy procedure, but could also have the capacity to provide predictive, diagnostic, and prognostic information.

The cortex and medulla of the kidney are believed to exist on a tightrope between normal function and hypoxia. The contributions of cortical and medullary hypoperfusion to hypertension have been widely investigated. In this Viewpoint, Thomas Pallone distills current knowledge on the roles of nitric oxide and reactive oxygen species in this setting, and speculates on the implications for future treatment of hypertension.

Elevated blood pressure is a strong and independent risk factor for the development of end-stage renal disease. Various investigators have examined whether all renal diseases are similarly sensitive to high blood pressure and whether they benefit similarly from antihypertensive therapy. Reviewing data from different renal disease populations, authors from the Medical University of Silesia provide their recommendations on the optimal blood pressure goals for slowing progression of renal insufficiency.

Transcriptome-based assessment of blood, urine or biopsy tissue could have a powerful impact on the management of renal transplants, with the potential to detect injurious mechanisms before graft injury is established. This Viewpoint article explores the promise held by transcriptomics and high-density microarrays, and examines the challenges of applying these new technologies in renal transplant recipients.

The plasma concentration of sodium ions normally exceeds the sum of the plasma concentrations of chloride and bicarbonate ions. Calculation of the resulting 'anion gap' can aid the diagnosis of various acid–base and electrolyte disorders. Michael Emmett discusses the utility of this approach, and highlights the potential disrupting factors which should be taken into account when interpreting anion gap calculations.