Moreover, we investigated the influences of age, gender, weight, and muscle mass on serum creatinine and serum cystatin c. Two elderly patients with normal creatinine and elevated. Comparing newer gfr estimating equations using creatinine and. Apr 02, 20 sentitivity and specificity of cystatinccreatinine 27.
Jul 01, 2014 the new equation includes age, a single coefficient exponent for serum cystatin c. Performance of cystatin cbased equations for estimation of. Our study cannot directly address whether serum cystatin c is a better clinical marker of kidney function compared with creatinine, because we have no direct measures of gfr. After age 50, reference values of serum cystatin c concentration are higher. Serum creatinine, serum cystatin c and 24hour creatinine clearance ccr were determined in 50 critically ill patients age. Recently, it has been studied for its role in predicting newonset or deteriorating cardiovascular disease. Nov 18, 2016 cardiorenal syndrome type 2 crs2 is characterized by chronic heart failure leading to chronic kidney disease ckd. In critically ill patients sudden changes in glomerular filtration rate gfr are not instantly followed by parallel changes in serum creatinine. Cystatin c forforgein2006 free download as powerpoint presentation. It also seems to play a role in brain disorders involving amyloid a specific type of protein.
The gfr was calculated using the cystatin c formula, the gfr can be estimated using other formulas such as the creatinine cystatin c equation, the cockcroftgault equation, or the mdrd equation. Simple cystatin c formula compared to serum creatininebased. Background and objectives the diagnostic accuracy of cystatin c estimated gfr egfr by various cystatin c equations have varied in different studies. We aimed to assess the reproducibility, reliability, and accuracy of plasma cystatin c as a measure of gfr ranging from normal to. Gfr based on serum cystatin c alone and in combination with serum creatinine. The production rate of cystatin c is remarkably constant and its plasma concentration can therefore be used as a reliable measure of the glomerular filtration rate gfr. We hypothesized that the gfr level of enrolled patients affects the diagnostic accuracy of a cystatin c equation. The objective of this study was to describe the normal range of serum cystatin c and identify factors associated with variability in serum cystatin c contrasting with factors that are known to influence creatinine levels in the general us adolescent population. Objective assessment and followup of early renal dysfunction is important in diabetic nephropathy. Gentian cystatinc gfr calculator the calculator gives instant conversion of cystatin c measurement to standard gfr units gfr calculator. However, we should like to draw attention to several flaws in this study. However, cystatin c has other potential confounders.
Apr 01, 2016 cystatin c is made by all nucleated cells, not just muscle. It has been used as an estimate of the severity of ckd because a high level of cystatin c is associated cardiovascular disease and may even be more closely associated than scr. Cystatin c or cystatin 3 formerly gamma trace, postgammaglobulin, or neuroendocrine basic polypeptide has been proposed as a valuable alternative marker tested in urine and in blood, particularly in situations in which creatininebased estimates of gfr fail to provide an accurate estimate. Backgrounddecreased glomerular filtration rate gfr is an important. Background estimates of glomerular filtration rate gfr, including creatinine and creatinine based formulae, are inaccurate in extremes of gfr and substantially biased in patients with chronic heart failure chf. Glomerular filtration rate gfr is the best overall index of kidney function. Cystatin cbased glomerular filtration rate associates more closely. Objective serum cystatin c is an alternative to serum creatinine for estimating glomerular filtration rate gfr, since cystatin c is less influenced by age and muscle mass. We read with interest the article by villa and coworkers 1 advocating the use of cystatin c as a measure of glomerular filtration rate gfr in critically ill patients. Simple cystatin c formula for estimation of glomerular filtration rate in overweight patients with diabetes mellitus type 2 and chronic kidney disease.
Comparing newer gfr estimating equations using creatinine. Using crosssectional analyses, we developed estimating equations. An index of glomerular filtration rate, especially in patients where serum creatinine may be misleading eg, very obese, elderly, or malnourished patients assessing renal function in patients suspected of having kidney disease monitoring treatment response in patients with kidney disease estimated glomerular filtration rate egfr. Several studies have examined the correlation of cystatin c with measures of gfr other than the gold standard of gfr measurement, inulin clearance, in pregnant women and these have yielded conflicting results. Gentian cystatinc gfr calculator the calculator gives instant conversion of cystatinc measurement to standard gfr units 31. The glomerular filtration rate should only be assessed in a steady state condition for reliable results. It has been used as an estimate of the severity of ckd because a high level of cystatin c is associated.
A blood test for cystatin c can help your healthcare provider find your gfr. Normal gfr varies according to age, sex, and body size, and declines with age. However, serum creatinine concentration is also influenced by nongfr determinants. When kidneys are working well, they keep the level of cystatin c in your blood just right. Cystatin c and creatininebased estimated glomerular. Sex and muscle mass independent in children 1 year. A possible advantage of cystatin c with minor glomerular damage is that, being a large molecule, blood levels of cystatin c. First, villa and coworkers compared cystatin c with creatinine as a measure of gfr, using body surface corrected creatinine clearance as, what they. We hypothesized that an egfr equation using cystatin c would outperform one using creatinine and compared the. Age, gender, and race effects on cystatin c levels in us. The gfr was calculated using the cystatin c formula, the gfr can be estimated using other formulas such as the creatininecystatin c equation, the cockcroftgault equation, or the mdrd equation. Cystatin c serum concentration is not influenced by gender, inflammation, or lean tissue mass and is regarded to be mainly determined by glomerular filtration rate gfr.
Cystatin c is a more reliable biomarker for determining. Cystatin c forforgein2006 renal function creatinine. Serum cystatin c concentration as a marker of acute renal. Before cystatin c can gain wide acceptance, information about factors that affect generation, elimination, and analysis is needed. Cardiorenal syndrome type 2 crs2 is characterized by chronic heart failure leading to chronic kidney disease ckd. Cystatin c is not affected by muscle mass or diet and is less strongly associated with age, sex, and race than creatinine, but smoking, inflammation, adiposity, thyroid diseases, malignancy, and glucocorticoids influence cystatin c levels, diminishing their value as a measure of renal excretory performance. If kidney function and glomerular filtration rate decline, the blood levels of cystatin c rise. Serum cystatin c, serum creatinine and creatinine clearance were measured in 226 patients with. Apr 17, 2014 in seniors gfr declines with age and cystatin c may better reflect true kidney function in older people because muscle mass does not influence it. How to use serum creatinine, cystatin c and gfr adc. Recent studies indicate that serum cystatin c is a better marker of glomerular filtration rate gfr and is a stronger predictor of cardiovascular disease and mortality than serum creatinine. Mar 02, 2009 recent studies indicate that serum cystatin c is a better marker of glomerular filtration rate gfr and is a stronger predictor of cardiovascular disease and mortality than serum creatinine. Diagnostic accuracy of cystatin cbased egfr equations at. Clarifying the confusion of gfrs, creatinine, and cystatin c article downloaded from creatinine mgdl gfr mlmin1.
Cystatin c is an alternative filtration marker for estimat ing gfr. His clinical recovery was more reflective of the higher gfr with cystatin c than what would be assumed with his serum creatinine, which at its worst was 5 mlmin1. Estimating glomerular filtration rate from serum creatinine. Serum cystatin c and creatinine were measured in 719.
Cystatin c or cystatin 3 formerly gamma trace, postgammaglobulin, or neuroendocrine basic polypeptide, a protein encoded by the cst3 gene, is mainly used as a biomarker of kidney function. Cystatin c and aging success geriatrics jama internal. Use of a single equation for each filtration marker or combination for egfr reporting would facilitate patient care. Pdf cystatin c concentration and glomerular filtration rate. Plasma creatinine is insensitive for a glomerular filtration rate gfr 50 mlmin and creatinine clearance is unwieldy and subject to collection inaccuracies. Cystatin c is a protein that is produced by the cells in your body.
Effects of glucocorticoid immunosuppression on serum. We aimed to assess the reproducibility, reliability, and accuracy of plasma cystatin c as a measure of gfr ranging from normal. Cystatin c is less subjected to the effect of age, gender and race than creatinine, and is also less affected by muscle mass and diet. Cys ccystatin c, scrserum creatinine, gfrglomerular filtration rate, rocreceiver, operating curve, crclcreatinine clearance full text the full text of this article is available as a pdf. The gfr is relatively low at birth but increases through infancy and early childhood to reach adult levels of approximately 120 mlmin1. Cystatin ca novel marker of glomerular filtration rate. In seniors gfr declines with age and cystatin c may better reflect true kidney function in older people because muscle mass does not influence it. A newer biomarker for gfr, cystatin c, has been shown to be subject to less biological interference and more sensitive to early declines in kidney function. In the estimation of glomerular filtration rate gfr, ethnicity is an important determinant. Cystatin c is a low molecularweight protein,000 da that is produced by all nucleated cells and acts to inhibit cysteine proteases.
Cystatin c for glomerular filtration rate estimation. Crosssectional studies based on a single point in time suggest that serum levels of cystatin c are a more precise test of kidney function as represented by the glomerular filtration rate, gfr than serum creatinine levels. Glomerular filtration rate was estimated using the cockcroftgault, modification of diet in renal disease mdrd and chronic kidney disease epidemiology collaboration ckdepi equations, as well as cystatin cbased equations ckdepi cystatin c, cystatin c van deventer and ckdepi combined compared to 51 credta. We compared the correlation, bias, precision, and accuracy of serum cystatin c egfr with respect to 99m tc dtpa gfr in the gfr groups of c measurement to standard gfr units gfr calculator. Among persons with diabetes, we compared the performance of gfr estimated using cystatin c egfrcys with that using creatinine egfrcr for the identification of reduced kidney function and its association with. Estimating glomerular filtration rate from serum creatinine and. Serum creatinine and cystatin c were significantly correlated with. Estimating glomerular filtration rate from serum creatinine and cystatin c. To reduce overdiagnosis of chronic kidney disease ckd resulting from the inaccuracy of creatininebased estimates of glomerular filtration rate gfr, uk and international guidelines recommend that cystatincbased estimates of gfr be used to confirm or exclude the diagnosis in people with gfr 4559 mlmin1.
Like serum creatinine, cystatin c concentrations were much more stable in individuals without renal disease than was gfr measured by creatinine clearance 5. Serum cystatin c sccbased formulas and the newer creatinine formula the chronic kidney disease. Correlation of cystatinc with glomerular filtration rate by. Ckd was defined as ckid gfr national kidney foundation recommends using the ckdepi creatinine equation 2009 to estimate gfr. Kdigo guidelines recommend using the ckdepi equations, but other equations are recommended if they are more accurate. However, after adjusting for established cardiovascular risk factors, hrs for both creatininebased ckd definitions were attenuated to point estimates of 1. Serum cystatin c as a marker of glomerular filtration rate curr opin nephrol hypertens. Performance of glomerular filtration rate estimation. Schwartz formula gfr was compared with novel methods. Cystatin c and creatininebased equations in the assessment.
Results during 5 years of followup, 95 individuals had a primary cardiovascular event. A total of 873 participants reached a first event in followup. The mean cystatin c level, creatinine level, and estimated glomerular filtration rate were 1. Cystatin c for gfr in pediatry cystatin c for reliable and sensitive gfr determination in pediatrics. If the level of cystatin c in your blood is too high, it may mean that your kidneys are not working well.
Cystatin c is made by all nucleated cells, not just muscle. The study population consisted of 100 treatmentnaive hiv patients. Cystatin c has also been shown to outperform creatinine as an indicator of true gfr and to add information about the. Clinical utility of creatinine and cystatin cbased. This case report presents two elderly patients with normal scr but elevated serum cystatin c concentration scys where the exclusive assessment of scr would have. Article information, pdf download for cystatin cbased glomerular. As a result, cystatin c production varies less than creatinine production between individuals, and blood concentrations of cystatin c are fairly similar between individuals who have the same gfr. Glomerular filtration rate gfr cystatin c evidencio. Pdf simple cystatin c formula for estimation of glomerular. Cystatin cbased glomerular filtration rate estimating. Cystatin c vs creatinine equation ckdepi cystatin pooled dataset.
While gfr can be measured most accurately by the urinary clearance of an exogenous ideal filtration marker such as inulin, it is more clinically useful to. Use of cystatin c levels in estimating renal function. Cystatin c is considered to be a potential alternative to serum creatinine for estimating gfr. Because patients with crs2 have cardiac cachexia from anorexia and increased catabolism,2 creatininebased egfr equations may be subject to important errors. Nov 01, 2001 cystatin c is a nonglycosylated basic protein.
Cystatin c versus creatinine for gfr estimation in ckd due. In obstetrics serum cystatin c concentration varies in pregnancy, because it is not consistently produced. Serum creatinine concentration scr and creatinine based gfr estimating equations egfrcr are commonly used as an estimate of gfr. The clinical utility and cost impact of cystatin c. The national kidney foundation recommends using the ckdepi creatinine equation 2009 to estimate gfr. Cystatin c has been reported to be a more accurate marker for acute kidney injury and better at estimating small changes in gfr, as blood levels of cystatin c. Recently, serum cystatin cbased equations, the newer creatinine formula the chronic kidney disease.
Effects of glucocorticoid immunosuppression on serum cystatin. Cystatin c has been described as meeting many of the characteristics of an ideal gfr marker e. Cystatin c versus creatinine for gfr estimation in ckd due to. On admission, the patients reduction in glomerular filtration rate gfr from baseline was much less when calculated with cystatin c than with serum creatinine. May 26, 2017 gfr estimation using creatinine, cystatin c, or both is now widely used in clinical practice in adults. The aim of the present study was to analyze the utility of serum cystatin c as a marker of renal function in these patients. Glomerular filtration rate was estimated using the cockcroftgault, modification of diet in renal disease mdrd and chronic kidney disease epidemiology collaboration ckdepi equations, as well as cystatin cbased equations ckdepi cystatin c, cystatin c van deventer and ckdepi combined compared to 51 credta plasma. Mitch, in seldin and giebischs the kidney fifth edition, 20. The new equation includes age, a single coefficient exponent for serum cystatin c. Pdf in clinical practice the glomerular filtration rate gfr is estimated from serum creatininebased. Objective to investigate whether serum cystatin c levels would be a better, more accurate and simple alternative for estimation of gfr and prognosis in chf.1136 69 363 1578 1577 1423 1542 273 1120 201 758 692 435 1237 298 770 351 1262 1041 1453 544 189 121 713 643 658 1426 743 368 600 994