News & Views in 2011

In contrast to reports of favorable survival in incident patients on peritoneal dialysis compared with hemodialysis, a recent study has shown similar survival outcome depending on type of vascular access. Central venous catheters for hemodialysis have an inherent risk of sepsis, which accounts for the early survival advantage of peritoneal dialysis.

Clinical practice guidelines recommend target serum levels for phosphorus, calcium and parathyroid hormone in patients with chronic kidney disease. However, a recent meta-analysis has found that only levels of phosphorus seem to be associated with the risk of death in these patients.

Genetic forms of steroid-resistant nephrotic syndrome are characterized by an unremitting clinical course, resistance to treatment and a favorable outcome after transplantation. The recognition of these diseases is essential, but difficult, owing to genetic and phenotypic heterogeneity. Such difficulties have led to the proposal of a systematic step-wise approach for mutational screening.

A recent study reports the expansion of the donor pool by using kidneys from donors after cardiac death with prolonged agonal time. The duration of the agonal period and hemodynamic instability do not influence kidney transplantation outcome, indicating that this approach is feasible and may help meet the need for donor kidneys for transplantation.

Results of a clinical trial reported in the New England Journal of Medicine suggest that the use of recombinant tissue plasminogen activator as a lock solution improves catheter patency and reduces the risk of catheter-related infections. These effects have important clinical and economic ramifications. So why is tissue plasminogen activator not more widely used?

Including proteinuria in the NKF KDOQI staging system for chronic kidney disease will increase the accuracy of risk stratification, but will not improve the precision of glomerular filtration rate (GFR) estimation by prediction formulas. Using markers of glomerular filtration other than serum creatinine will hopefully enable implementation of novel formulas that more precisely estimate true GFR, especially in individuals with near-normal renal function.

Uncertainty exists over whether hemodialysis or peritoneal dialysis is the modality associated with better survival in patients with end-stage renal disease. Mehrotra and colleagues have shown that survival rates have improved more with peritoneal dialysis than with hemodialysis in more recent cohorts of US patients starting dialysis and that, overall, the two modalities have very similar 5-year mortality rates.

The consequences of fluid administration and the maintenance of fluid balance, despite their ubiquity in critical care, remain a topic of much debate among clinicians. Emerging evidence suggests that fluid administration and a positive fluid balance can be harmful in a number of conditions, including acute kidney injury.

Results from the ROADMAP trial have highlighted the discrepancy between the renoprotective effects of olmesartan treatment in patients with type 2 diabetes mellitus, and the observed increase in cardiovascular deaths. Several explanations for these results need to be considered, which may influence future clinical practice.

In response to data from trials showing an increase in clinical events with the use of erythropoiesis-stimulating agents (ESAs), Seliger et al. carried out an observational case–control study and have found that high doses of ESAs are associated with an increased risk of stroke.

In the CKiD study, extracellular fluid volume (ECV) was estimated from plasma iohexol curves in children with chronic kidney disease. A simple formula for ECV that uses weight and height data has now been derived. No relationship existed between weight-normalized ECV and hypertension, suggesting that volume overload does not underlie hypertension in this population.

A recent article exposes the ongoing industry of transplant tourism in China, where foreign patients can receive vendor organs recovered from executed prisoners. Concerning data reveal the long-term complications of kidney transplant tourism, particularly the increased risk of malignancy. These findings relay an important message to transplant communities and physicians worldwide.

Restriction of dietary phosphorus has long been established as a cornerstone for the treatment of hyperphosphatemia in patients on dialysis. However, the study by Lynch et al. published in the Clinical Journal of the American Society of Nephrology reports that prescribed dietary phosphorus restriction is not associated with improved survival among patients undergoing hemodialysis.

Arterial calcification is highly prevalent in patients with chronic kidney disease, and is a process associated with cardiovascular morbidity and mortality. Calcium phosphate deposits may be found in the intima, the media, or both. Whether determination of the precise location of calcification is possible and whether this distinction is clinically useful remains a matter of debate.

In light of recent proposed changes to the deceased donor allocation policy in the USA, considerable interest has arisen in the development of assessment tools to grade donor organ quality. Kahu and colleagues have suggested a new donor risk score that incorporates 10 distinct donor characteristics, correlating their presence with baseline histologic findings and graft outcomes.

A recent observational study from the UK raises questions over the control of mineral metabolism parameters to within target levels defined by the KDOQI clinical practice guidelines. Data from this study highlight the need for a randomized controlled trial to determine whether optimal management of bone mineral metabolism actually provides any survival benefit.

Individuals with HIV disease frequently experience kidney dysfunction, which is accompanied by an increased risk of cardiovascular disease and death. Choi et al. have found that albuminuria and an estimated glomerular filtration rate of <60 ml/min/1.73 m², estimated using serum cystatin C level, accounted for 17% of the population-attributable 5-year mortality risk in a cohort of patients with HIV infection.

Antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis is a common cause of acute kidney injury in the elderly. This patient group is particularly susceptible to disease-related morbidity and mortality, and to adverse effects of induction immunosuppression. A new study adds to the debate on the most appropriate way to treat this vulnerable group of patients.

March 10, 2011 will mark the 6^th World Kidney Day, an annual event jointly sponsored by the International Society of Nephrology and the International Federation of Kidney Foundations. World Kidney Day aims to raise awareness among both the general public and government health officials about the dangers of kidney disease, especially chronic kidney disease.

The staging of chronic kidney disease requires measurement of glomerular filtration rate (GFR). As direct GFR measurement is impractical, estimates are used. The MDRD equation was 'Hobson's choice' and although known to be unreliable at higher levels of kidney function it is still in widespread use. The CKD-EPI equation is a new alternative. Is it better?