Nephron News
Nephron NEWS
(Updated on Nov.26.2008)
Issue 3, 2008 [November 26, 2008]
The December issue of Nephron Clinical Practice Vol. 110, No. 4, 2008 includes a number of articles dealing with the pressing matter of global CKD. This issue of Nephron News includes a commentary on the mini review by Iseki addressing CKD detection programs in Japan. I also discuss the article by Emara et al. concentrating on issues related to the accuracy and precision of a number of GFR estimation equations for the detection of mild-moderate CKD. Finally, I summarize the World Kidney Day CKD screening experience of Sumaili et al. in the Democratic Republic of Congo.
Please do not hesitate to write to me and share your experience of screening for CKD in your community.
Professor Meguid El Nahas, PhD, FRCP
Editor, Nephron Clinical Practice
nephron@sheffield.ac.uk
m.el-nahas@sheffield.ac.uk
The mini review by Iseki (2008;110:c268-c272) highlights issues relating to CKD in Japan. Over the last 25 years, Japan has led the way in CKD screening strategies with data emanating from Okinawa identifying a number of community-based risk factors. This editorial examines some of the known data and reviews new initiatives. It becomes apparent that, as elsewhere in the world, Japan may have a high prevalence of CKD; unfortunately, as with many reports, such a prevalence includes many with an eGFR between 50 and 59 ml/min/1.73m_ who may jump in and out of CKD stage 3 based on serum creatinine estimation variability and/or may simply have age-related low GFR with little risk of progression. This is commented upon by the fact that progression seldom takes place in the absence of hypertension, diabetes or proteinuria. Iseki also introduces the reader to a number of Japanese and Asian CKD initiatives aimed at improving CKD awareness and planning strategies. It is encouraging to know that issues relating to CKD and its impact on global healthcare are prompting a number of national and regional initiatives. These are welcomed in view of the paucity of solid data underlying a number of dogmatic statements relating to CKD, its prevalence and complications.
The article by Emara et al. (2008;110:c195-c206) from the Shoker group at the Saskatchewan Nephrology Unit in Canada explores issues relating to the comparative accuracy and precision of a number of estimated GFR equations based on serum cystatin C and creatinine measurements in patients with mild to moderate CKD (stages 2 and 3).
Cystatin C is a low-molecular-weight protein which has been proposed as a marker of renal function that could replace creatinine. The concentration of cystatin C is mainly determined by glomerular filtration and is particularly of interest in clinical settings where the relationship between creatinine production and muscle mass impairs the clinical performance of creatinine. Since the last decade, numerous studies have evaluated its potential use in measuring renal function in various populations (S. Seronie-Vivien et al., Clin Chem Lab Med 2008;46:Epub ahead of print).
Emara et al. suggest that equations based on cystatin C levels are not more sensitive or precise than those based on serum creatinine estimation in patients with mild to moderate CKD. They conclude that currently available equations are not sufficiently precise to fulfill the KDOQI guidelines and that more sensitive equations may need to be formulated to avoid missing individuals with mild to moderate CKD.
Of note, recent attempts have been made to generate GFR estimation equations combining serum creatinine and cystatin C values. An equation including serum cystatin C level in combination with serum creatinine level, age, sex, and race provides the most accurate estimates (Stevens et al., Am J Kidney Dis 2008;51:395-406).
Sumaili et al. (2008;110:c220-c228) from Kinshasa University undertook a cross-sectional survey of around 3000 individuals on World Kidney Day and noted that over 17% had proteinuria. The majority of those with proteinuria had associated chronic disease such as diabetes (~25%), metabolic syndrome (~20%) or hypertension (20%). Also, and as expected, more than 20% of those with proteinuria were older than 50 years. Diabetes, obesity and old age were independently associated with proteinuria. However, before proclaiming such high prevalence of proteinuria, caution should be exerted in view of the following: 1) the great majority of those with proteinuria (14.8% of the 17.1%) had 1+ on dipstick analysis, with very few with more substantial levels of proteinuria (++ and +++). False-positive results are quite common at this low level of proteinuria. 2) Cross-sectional analyses do not allow confirmation of chronicity, and repeated testing should be undertaken to confirm such abnormalities and to characterize CKD. Many studies have created the impression that CKD affects a significant percentage of the population; many studies have been based on single, cross-sectional estimations of albuminuria and proteinuria. More rigorous and repeated analyses are warranted to avoid overinflating the CKD healthcare problem in Africa and the emerging world.
| page top |
Nephron NEWS
(Updated on Nov.04.2008)
Issue 2, 2008 [November 04, 2008]
The following three papers, chosen from the October issue of Nephron Clinical Practice (Vol. 110, No. 3, 2008), highlight the growing interest in biomarkers in nephrology. In acute kidney injury, CKD as well as in hemodialysis, biomarkers are sought that can lead to early diagnosis - facilitating detection - as well as give prognostic indications over and above those currently in clinical use. With this issue of Nephron News, we encourage readers to share their experience gained with biomarkers in AKI, CKD and HD patients.
Professor Meguid El Nahas, PhD, FRCP
Editor, Nephron Clinical Practice
nephron@sheffield.ac.uk
m.el-nahas@sheffield.ac.uk
Urinary Sediment Cast Scoring Index for Acute Kidney Injury: A Pilot Study
Lakhmir S. Chawla, Aaron Dommu, Alexandra Berger, Shirley Shih, Samir S. Patel
Nephron Clin Pract 2008;110:c145-c150
Nephrologists from the Division of Nephrology and Hypertension at George Washington University Medical Center have devised a new acute kidney injury (AKI) urinary cast scoring system aimed at evaluating the severity of acute tubular necrosis:
Fig. 2. Granular cast index. GC = Granular casts; ECC = epithelial cell casts; LPF = low-power field (x10). The approach to viewing slide was to search for casts (GCs or ECCs), then view the entire slide.
The authors found the scoring system easy to use and quite reproducible. It is hoped that such a scoring system may undergo further validation and dissemination. It may provide useful prognostic information related to the severity of acute tubular necrosis. Ideally, comparisons of the severity proposed by the scoring system and that of the histological changes should be undertaken. Recently, research and interest have increasingly focused on early diagnostic and prognostic markers of AKI including biomarkers such as Interleukins, Kim-1 (Kidney Injury Molecule-1) and NGAL (Neutrophil Gelatinase-Associate Lipocalin); the Granular cast index described in this publication may be used in conjunction with some of these markers.
Relative Contribution of Morphometric and Functional Indicators of Tubulointerstitial Lesion to Glomerular Diseases Prognosis
Rogerio Barbosa de Deus, Vicente de Paulo Castro Teixeira, Gianna Mastroianni Kirsztajn
Nephron Clin Pract 2008;110:c164-c171
Brazilian Nephrologists and pathologists have investigated in this publication the value of urinary Retinol-Binding Protein (RBP) as a marker of tubular damage and interstitial fibrosis in patients with a range of glomerulonephritis. urRBP proved to predict the severity of tubular atrophy as well as interstitial fibrosis. RBP is a small molecular weight protein and the correlation between its urinary excretion and tubular damage is caused by a number of factors including increased filtration, saturation of proximal tubule uptake of that protein or, most likely, decreased proximal tubule reabsorption of filtered RBP by damaged and atrophic tubules. There is currently a controversy as to the extent of glomerular permeability to proteins and the role of proximal tubule dysfunction in proteinuria. This paper highlights the point that tubular damage is associated with significant proteinuria including albuminuria, transferrinuria as well as RBPuria. The role of tubular damage in proteinuria and peptiduria associated with glomerulonephritis is not fully appreciated as it may play a significant role in the severity of the overall urinary protein leak.
Predictive Role of BNP and NT-proBNP in Hemodialysis Patients
Linlin Sun, Yan Sun, Xuezhi Zhao, Chenggang Xu, Dongping Chen, Lin Li, Yiyi Ma, Shu Rong, Changlin Mei
Nephron Clin Pract 2008;110:c178-c184
In this publication, the group of Professor Mei in Shanghai confirms previous observations that serum BNP (B type-natriuretic peptide) and NT-proBNP levels predict cardiovascular mortality, myocardial infarction as well as congestive heart failure in patients treated by emodialysis. BNP is released from the myocardium (cardiomyocytes) after injury, and levels are raised in hemodialysis patients. These biomarkers are emerging as powerful predictors of cardiovascular events and mortality in patients on renal replacement therapy.
To unsubscribe from this service, please send an email to: y.rebmann@karger.ch
| page top |
Nephron NEWS
(Updated on Oct.17.2008)
Issue 1, 2008 [October 17, 2008]
Welcome Note
by the Editor, Meguid El Nahas
I am delighted to announce the launch by Karger of Nephron News in October 2008. Nephron News is a new global nephrology information service aimed at providing nephrologists worldwide, in particular those practicing in the emerging world, with up-to-date clinical information. Nephron News will provide, by e-mail, a monthly synopsis of important Nephron Clinical Practice articles and mini-reviews with editorial comments.
It is hoped that rapid and easy access to such clinical information and updates will prove helpful and informative for those who don't have regular access to Nephron. Those receiving the information will also be welcomed to enter into an e-mail dialogue with the editor (e-mail address given below). They will be encouraged to comment on the articles and to share their own views and practices.
Furthermore, it is hoped that through this new global information channel nephrologists will be encouraged to submit their latest clinical observations and research to Nephron.
Nephron News is a unique and innovative approach to promote worldwide Continuing Nephrological Education. It is an independent and purely scientific service provided by Nephron for nephrologists from emerging countries and other interested individuals. We encourage all nephrologists to be actively involved through comments and feedbacks to the editor and also to forward Nephron News to interested friends and colleagues. Nephron News is free of charge and not sponsored by corporate or private sources.
Professor Meguid El Nahas, PhD, FRCP
Editor, Nephron Clinical Practice
nephron@sheffield.ac.uk
m.el-nahas@sheffield.ac.uk
To unsubscribe from this service, please send an email to: y.rebmann@karger.ch
| page top |
Copyright© 2009 Japanese Society of Nephrology All Rights Reserved.