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Inaccuracy of GFR predictions by plasma cystatin C in patients without kidney dysfunction and in advanced kidney disease.

Bakoush, Omran LU ; Grubb, Anders LU and Rippe, Bengt LU (2008) In Clinical Nephrology 69(5). p.331-338
Abstract
BACKGROUND: In clinical practice there is need for a simple and reliable test for determination of impaired renal function. With reductions in GFR, the plasma cystatin C concentration (C, mg/l) will increase earlier than serum creatinine, and it is generally agreed that plasma cystatin C is only little affected by body weight, age or sex. However, some reports indicate that cystatin C may be influenced not only by GFR, but also by malignancy, inflammation and high doses of corticosteroids. The aim of the present study was to investigate how plasma cystatin C predicts GFR in distinct subcategories of patients with various disorders as well as in organ transplant patients. METHODS: Plasma cystatin C was measured in 536 patients (age range... (More)
BACKGROUND: In clinical practice there is need for a simple and reliable test for determination of impaired renal function. With reductions in GFR, the plasma cystatin C concentration (C, mg/l) will increase earlier than serum creatinine, and it is generally agreed that plasma cystatin C is only little affected by body weight, age or sex. However, some reports indicate that cystatin C may be influenced not only by GFR, but also by malignancy, inflammation and high doses of corticosteroids. The aim of the present study was to investigate how plasma cystatin C predicts GFR in distinct subcategories of patients with various disorders as well as in organ transplant patients. METHODS: Plasma cystatin C was measured in 536 patients (age range 0.3-96 years, 262 females, 274 males), consecutively referred to our hospital for determination of GFR by iohexol clearance. Correlations of log GFR vs. log cystatin C were used to compare plasma cystatin C and measured GFR for the following categories: individuals with no known kidney disease (No-KD), malignant patients with (mostly) normal GFR, solid organ-transplanted patients, and patients with native chronic kidney disease (CKD). RESULTS: In patients with normal kidney function and cystatin C level <or= 1 mg/l, the cystatin C was poorly correlated with GFR (R2=0.13). By contrast, in patients with chronic kidney disease (log) plasma cystatin C was highly correlated with (log) GFR (R2=0.87). This correlation was more or less unchanged whether the cause of the reduction in GFR was CKD at Stages 1-3 (90>GFR>30 ml/min(-1) (1.73 m2)(-1)) or solid organ transplantation (GFR=84.55 C(1.7666) and GFR=83.95(C-1.5968), respectively). CONCLUSION: Therefore, for these categories, a common equation for all patients with increased cystatin C, irrespective of cause of renal impairment, could be used, namely that presented by Grubb et al. [2005] (GFR=83.93(C-1.676)). However, at marked reductions of renal function (GFR<30 or cystatin C>2), i.e. for CKD Stages 4 and 5, the Grubb prediction equation is less accurate. Based on our data, we suggest the equation GFR=50.52 C(-1.26) for this category of patients. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Clinical Nephrology
volume
69
issue
5
pages
331 - 338
publisher
Dustri-Verlag
external identifiers
  • WOS:000256352800003
  • PMID:18538095
  • Scopus:43449111534
ISSN
0301-0430
language
English
LU publication?
yes
id
52734301-2582-4c77-b5ed-791272a33fc4 (old id 1169041)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/18538095?dopt=Abstract
date added to LUP
2008-07-03 11:57:36
date last changed
2016-10-13 04:30:39
@misc{52734301-2582-4c77-b5ed-791272a33fc4,
  abstract     = {BACKGROUND: In clinical practice there is need for a simple and reliable test for determination of impaired renal function. With reductions in GFR, the plasma cystatin C concentration (C, mg/l) will increase earlier than serum creatinine, and it is generally agreed that plasma cystatin C is only little affected by body weight, age or sex. However, some reports indicate that cystatin C may be influenced not only by GFR, but also by malignancy, inflammation and high doses of corticosteroids. The aim of the present study was to investigate how plasma cystatin C predicts GFR in distinct subcategories of patients with various disorders as well as in organ transplant patients. METHODS: Plasma cystatin C was measured in 536 patients (age range 0.3-96 years, 262 females, 274 males), consecutively referred to our hospital for determination of GFR by iohexol clearance. Correlations of log GFR vs. log cystatin C were used to compare plasma cystatin C and measured GFR for the following categories: individuals with no known kidney disease (No-KD), malignant patients with (mostly) normal GFR, solid organ-transplanted patients, and patients with native chronic kidney disease (CKD). RESULTS: In patients with normal kidney function and cystatin C level &lt;or= 1 mg/l, the cystatin C was poorly correlated with GFR (R2=0.13). By contrast, in patients with chronic kidney disease (log) plasma cystatin C was highly correlated with (log) GFR (R2=0.87). This correlation was more or less unchanged whether the cause of the reduction in GFR was CKD at Stages 1-3 (90&gt;GFR&gt;30 ml/min(-1) (1.73 m2)(-1)) or solid organ transplantation (GFR=84.55 C(1.7666) and GFR=83.95(C-1.5968), respectively). CONCLUSION: Therefore, for these categories, a common equation for all patients with increased cystatin C, irrespective of cause of renal impairment, could be used, namely that presented by Grubb et al. [2005] (GFR=83.93(C-1.676)). However, at marked reductions of renal function (GFR&lt;30 or cystatin C&gt;2), i.e. for CKD Stages 4 and 5, the Grubb prediction equation is less accurate. Based on our data, we suggest the equation GFR=50.52 C(-1.26) for this category of patients.},
  author       = {Bakoush, Omran and Grubb, Anders and Rippe, Bengt},
  issn         = {0301-0430},
  language     = {eng},
  number       = {5},
  pages        = {331--338},
  publisher    = {ARRAY(0x992ad68)},
  series       = {Clinical Nephrology},
  title        = {Inaccuracy of GFR predictions by plasma cystatin C in patients without kidney dysfunction and in advanced kidney disease.},
  volume       = {69},
  year         = {2008},
}