Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01034 (cystatin C)
 3,397 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A controversy presently exists concerning the ability of albumin to inhibit the tubular reabsorption of low-molecular-weight (M(r)) proteins in experimental renal diseases leading to massive proteinuria. We have examined the urinary excretion of albumin and of 2 low-M(r) proteins, beta 2-microglobulin and cystatin C, in rats treated with toxins affecting primarily the glomerulus (puromycin amino-nucleoside and Adriamycin) or the tubule (mercuric chloride and maleic acid). Above a threshold of 100 mg/24 h, albuminuria induced by puromycin aminonucleoside (50 mg/kg) and Adriamycin (5 mg/kg) was associated with a marked increase in the urinary excretion of beta 2-microglobulin and cystatin C peaking at more than 100-fold the baseline levels. These glomerulotoxins did not affect the urinary excretion of the tubular enzyme N-acetyl-beta-D-glucosaminidase. This pattern of effects was completely different from that induced by mercuric chloride (2 mg/kg) and maleic acid (400 mg/kg) which increased the excretion of both N-acetyl-beta-D-glucosaminidase and low-M(r) proteins in rats with albuminuria values below 100 mg/24 h. These results strongly support the hypothesis that at high filtered loads, albumin decreases the tubular uptake of low-M(r) proteins most likely by competition for a common transport mechanism.
Nephron 1994
PMID:Competition between albumin and low-molecular-weight proteins for renal tubular uptake in experimental nephropathies. 801 51

A clinical investigation was conducted to clarify the reliability and efficacy of serum cystatin C measurement for estimation of the glomerular filtration rate (GFR). Two hundred twelve patients with various renal diseases enrolled in the study. All patients were evaluated for 24-hour creatinine clearance (24 h C(Cr)) and the standard sodium thiosulfate clearance test (C(Thio)) within a week of blood sample collection. Serum cystatin C concentration was determined by a particle-enhanced immunonephelometry method. C(Thio) and 1/cystatin C, 24 h C(Cr), 1/beta2-microglobulin and 1/creatinine were well correlated. The correlation coefficients for C(Thio) obtained by 24 h C(Cr) and 1/cystatin C were comparable to each other (0.701 vs. 0.679). Receiver-operated characteristic (ROC) analysis revealed that 24 h C(Cr) showed the highest area under the curve when C(Thio) = 60 ml/min or C(Thio) = 100 ml/min were applied as the discrimination point. However, the ROC value obtained by cystatin C was slightly greater than 24 h C(Cr) when C(Thio) = 80 ml/min was used as the discrimination point. Patient age, gender, glucose tolerance, presence of proteinuria, systemic inflammation, lupus, or systemic use of steroids did not interfere in the relationship between C(Thio) and 1/cystatin C. In conclusion, serum cystatin C measurement is an excellent diagnostic test for detecting patients with subclinical renal dysfunction.
Nephron 2002 May
PMID:Serum cystatin C reliably detects renal dysfunction in patients with various renal diseases. 1202 14

We determined the relationship between the levels of serum cystatin C or creatinine (s-Cr) and the grade of creatinine clearance (CCr) in patients with various glomerular diseases. Serum samples from 96 patients with glomerular diseases were obtained from our hospital. The levels of serum cystatin C were measured using the Dade Behring Cystatin C assay with the automated Dade Behring Nephelometer II (BNII). CCr levels were classified into six groups according to the Guidelines of the Japanese Society of Nephrology as follows: grade 1 (normal renal function); grade 2 (slight decrease of renal function); grade 3 (moderate decrease of renal function); grade 4 (severe decrease of renal function); grade 5 (renal failure), and grade 6 (uremia). The mean levels of serum cystatin C in grade 3 patients were significantly higher than those in grade 1. The mean levels of serum cystatin C in grades 4, 5 and 6 patients were also significantly higher than those in grade 1. However, the mean levels of serum Cr in grade 3 patients were not significantly higher than those in grade 1. The levels of s-Cr in grades 4, 5 or 6 patients were significantly higher than those in grade 1. In this study, an increase of serum cystatin C levels occurred earlier than that of s-Cr in various glomerular diseases. It appears that the levels of serum cystatin C may provide early prognostic marker of patients with various glomerular diseases rather than the levels of s-Cr.
Nephron 2002 Sep
PMID:Serum cystatin C is a more sensitive marker of glomerular function than serum creatinine. 1218 9

Dosage regimes of aminoglycosides and vancomycin are modified according to the glomerular filtration rate (GFR). In 130 hospitalized patients who were administered amikacin, gentamicin, tobramycin, and vancomycin by intermittent intravenous infusion, we compared the predicted GFR values from the serum concentrations of creatinine (Cockcroft and Gault. Nephron. 1976;16:31-41) and cystatin C (Larsson et al. Scand J Clin Lab Invest. 2004;64:25-30) with respect to their relevance for proper dosage. In 83% and 67% of the cases, respectively, the serum levels of albumin and cholinesterase were below the corresponding lower limit of the reference range. The ratio of creatinine/cystatin C concentrations presented significant correlations with the predicted rate of creatinine production (r=0.762, P<0.001), serum albumin concentration (r=0.205, P<0.05), and catalytic serum concentrations of cholinesterase (r=0.207, P<0.05), gamma glutamyltransferase (r=-0.273, P<0.01), and alkaline phosphatase (r=-0.289, P<0.01). The GFR (mean+/-SD; median) predicted by the serum creatinine (84.0+/-35.1 mL/min/1.73 m; 82.6 mL/min/1.73 m) was significantly higher (P<0.001) than that predicted by the serum cystatin C (53.1+/-30.2 mL/min/1.73 m; 44.9 mL/min/1.73 m). The ratio between the GFR values predicted by creatinine and cystatin C had a highly significant negative correlation with the rate of creatinine production (r=-0.912, P<0.001). Furthermore, significant differences were found for the peak concentrations and clearances of amikacin and vancomycin estimated by means of the Abbottbase Pharmacokinetic Systems program, and using the GFR values predicted by the serum creatinine and cystatin C (P<0.005). In patients with hepatic dysfunction, the clearance of creatinine predicted by the Cockcroft-Gault formula leads to a significant overestimation of the GFR. Cystatin C seems to be a valid alternative as a GFR marker with regard to drug dose adjustment in these cases.
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PMID:Serum cystatin C for the prediction of glomerular filtration rate with regard to the dose adjustment of amikacin, gentamicin, tobramycin, and vancomycin. 1677 15

Presence of chronic kidney disease (CKD) defined as decreased glomerular filtration rate (GFR) and/or increased urine albumin excretion is associated with heightened risk of cardiovascular disease (CVD) and all-cause as well as CVD mortality. Although CKD is strongly linked with CVD, it remains undetermined whether this strong association is simply due to shared CVD risk factors or unique traits consequential to CKD. The probability of future CVD events can be estimated with reasonable accuracy using the Framingham equation which was derived from the Framingham study, a community-based cohort of 5,209 white adults aged 30-62 years who were first examined in 1948. Efforts to capture excess CVD risk associated with CKD have been evaluated by adding estimated GFR, cystatin C, serum creatinine and measures of urinary albumin excretion to the Framingham equation which is based on traditional cardiovascular risk factors. Although decreased GFR and increased urine albumin excretion are consistently associated with cardiovascular outcomes, the addition of these factors to the Framingham equation has not been shown to substantially improve overall CVD risk prediction in populations not enriched with CKD. Moreover, the Framingham equation itself underpredicts cardiovascular events among adults with stage 3 and 4 CKD without clinical CVD. Given the poor performance of the Framingham equation in adults with CKD, future studies should explore risk equations which include traditional CVD risk factors and the unique comorbidities associated with CKD for prediction of cardiovascular events in adults with CKD.
Nephron Clin Pract 2011
PMID:Should eGFR and albuminuria be added to the Framingham risk score? Chronic kidney disease and cardiovascular disease risk prediction. 2181 Oct 78

Drug dosing in accordance with the renal function is a long-standing challenge to clinicians. For many years it has been evident that in many clinical situations there is no easy way to correctly dose any drug that is mainly cleared by the kidneys. Despite the development of many formulas for estimating the glomerular filtration rate, they all have serious shortcomings. Much effort has been put in to develop estimation formulas to evaluate the renal function as an alternative to direct methods with the aim of safely dosing drugs that are mainly cleared by the kidneys. Both creatinine- and cystatin C-based formulas with additional clinical and biochemical parameters deduced from association studies with methods to measure the glomerular filtration rate (mGFR) have been developed. None of them have been good enough to perform safely in the wide range of situations in daily clinical praxis. Despite serious limitations, there has also been a tendency to use estimated GFR (eGFR) as a "hard" clinical endpoint in clinical studies. This has increased the risk of misinterpretation and has led to conclusions that are not necessarily supported by data. Finally, new methods of testing drug toxicity and the use of pharmacological support in order to fix the right doses are mentioned in this short overview of studies; possible problems that are encountered using eGFR instead of mGFR in the clinic and in research are also mentioned in this report.
Nephron 2017
PMID:Drug Dosing and Estimated Renal Function - Any Step Forward from Effersoe? 2821 41