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)

Hyperhomocysteinemia is an independent risk factor for coronary, peripheral and cerebrovascular diseases. Moderately elevated total homocysteine (tHcy) levels have been reported in patients with overt hypothyroidism. Plasma tHcy concentration is affected by several physiological factors and is elevated under conditions of impaired folate and cobalamin status and in renal failure. The aim of this study was to assess plasma tHcy concentrations and to evaluate the role of potential determinants of plasma tHcy levels in hypothyroid patients. Fasting plasma tHcy, serum homocysteine-related vitamins folate and vitamin B(12), serum cystatin C (CysC) and creatinine, were determined in 22 hypothyroid patients and compared with 25 healthy control subjects. Creatinine clearance (CCr) was calculated using the Cockroft-Gault formula. Plasma tHcy levels were determined by HPLC with fluorescence detection and serum CysC by automated particle enhanced immunoturbidimetry. Plasma tHcy, creatinine levels were significantly higher, and serum CysC levels, and creatinine clearance values were lower in hypothyroid patients than in control subjects. Folate levels were lower in hypothyroidic group compared to the control group. There were no differences in vitamin B(12) levels between hypothyroid and control groups. Positive correlation was noted between tHcy and creatinine levels in hypothyroid patients (r = 0.596); however, an inverse correlation was found between tHcy and folate levels (r = -0.705) in hypothyroid patients. In conclusion, tHcy was increased in hypothyroidism, and this increase was more strongly associated with changes in serum folate than in serum creatinine and CysC, suggesting an altered folate status.
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PMID:Impact of renal function or folate status on altered plasma homocysteine levels in hypothyroidism. 1654 81

A high level of albuminuria and increased renal vascular resistance are associated with hypertensive renal damage. In this study, the authors investigated the effect of the angiotensin II receptor blocker, valsartan, on renal function and intrarenal hemodynamics in non-diabetic patients with essential hypertension. A prospective three-month study of the effects of valsartan, 40-80 mg/day, was performed in 30 hypertensive patients. As an assessment of renal function, serum creatinine, urine albumin/creatinine (Alb/Cr) ratio, and serum cystatin C levels were evaluated. Doppler ultrasonography of the kidney was performed for the evaluation of renal hemodynamics. Peak-systolic, end-diastolic, and mean velocities of interlobar arteries were evaluated, and the pulsatility index (PI) and resistive index (RI) were calculated. It was determined that patients with microalbuminuria had higher levels of serum cystatin C, PI, and RI compared to patients without microalbuminuria. Valsartan treatment significantly reduced systolic and diastolic blood pressure and decreased the Alb/Cr ratio. Serum creatinine was not changed, whereas serum cystatin C levels were significantly reduced. Valsartan treatment significantly decreased the PI in all patients and both PI and RI in patients with microalbuminuria. These results suggest that the angiotensin II receptor blocker, valsartan, is able to improve renal function by reducing renal vascular resistance in hypertensive patients, especially in patients with microalbuminuria, and may prevent future renal failure in patients with essential hypertension.
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PMID:Valsartan reduces serum cystatin C and the renal vascular resistance in patients with essential hypertension. 1682 Mar 42

Although previously studied in patients with chronic kidney disease, there is less data for the use of cystatin C and cystatin C-based formulas in heart transplant recipients. The ability of creatinine and cystatin C to detect renal failure (glomerular filtration rate [GFR] below 60 mL/min/1.73 m(2)) in heart transplant patients has been compared. The accuracy and precision of a creatinine-based formula (Modification of Diet in Renal Disease [MDRD]) versus a cystatin C-based formula (Rule's formula) to estimate GFR have also been studied. GFR was measured using the (51)Cr-ethylenediamine tetraacetic acid tracer in 27 patients. There was no significant difference between GFR and the reciprocal of creatinine or cystatin C. Receiver operating characteristic curves for cystatin C and creatinine were similar. Both formulas were well correlated with the GFR. The bias of the cystatin C-based was significantly better than one of the MDRD formula, but the standard deviation appeared better for the MDRD formula (bias of +3.9 mL/min/1.73 m(2) versus +12 mL/min/1.73 m(2) and SD of 8.5 versus 11.6, respectively). Plasma cystatin C has no clear advantage over serum creatinine to detect renal failure in heart transplanted patients.
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PMID:Is cystatin C useful for the detection and the estimation of low glomerular filtration rate in heart transplant patients? 1735 68

Accurate renal function measurement is important for identification of chronic renal disease which may allow early implementation of renoprotective therapy and proper medication dosing among elderly individuals. This paper proposed to review available data about the strengths and weaknesses of current methods of measuring and estimating of renal function and to appoint which of them is the best in older people. Serum creatinine and creatinine clearance are inaccurate screening tests for renal failure in elderly subjects leading to under-recognition and/or underestimation of the degree of renal failure due to the reduced muscle mass and the inappropriate collection of a timed urine sample (urinary incontinence, cognitive impairment). For all their limitations, formulaic estimates of glomerular filtration rate can provide better information in this population. Further researches must be focused on development of a more precise estimation equation and on implementation in clinical practice of a novel marker of renal function, serum cystatin C, claimed to be superior to plasma creatinine in the elderly individuals.
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PMID:[Assessing renal function in elderly people]. 1759 43

An estimated 650,000 Americans will have ESRD by 2010. Young adults with kidney failure often develop progressive chronic kidney disease (CKD) in childhood and adolescence. The Chronic Kidney Disease in Children (CKiD) prospective cohort study of 540 children aged 1 to 16 yr and have estimated GFR between 30 and 75 ml/min per 1.73 m2 was established to identify novel risk factors for CKD progression; the impact of kidney function decline on growth, cognition, and behavior; and the evolution of cardiovascular disease risk factors. Annually, a physical examination documenting height, weight, Tanner stage, and standardized BP is conducted, and cognitive function, quality of life, nutritional, and behavioral questionnaires are completed by the parent or the child. Samples of serum, plasma, urine, hair, and fingernail clippings are stored in biosamples and genetics repositories. GFR is measured annually for 2 yr, then every other year using iohexol, HPLC creatinine, and cystatin C. Using age, gender, and serial measurements of Tanner stage, height, and creatinine, compared with iohexol GFR, a formula to estimate GFR that will improve on traditional pediatric GFR estimating equations when applied longitudinally is expected to be developed. Every other year, echocardiography and ambulatory BP monitoring will assess risk for cardiovascular disease. The primary outcome is the rate of decline of GFR. The CKiD study will be the largest North American multicenter study of pediatric CKD.
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PMID:Design and methods of the Chronic Kidney Disease in Children (CKiD) prospective cohort study. 1769 20

Chronic kidney disease (CKD) is a world-wide public health problem, with adverse outcomes of kidney failure, cardiovascular disease, and premature death. The National Kidney Foundation, through its Kidney Disease Quality Outcome Initiative (K/DOQI) and other National institutions, recommend glomerular filtration rate (GFR) estimates for the definition, classification, screening, and monitoring of CKD. Prediction equations based on serum creatinine values were chosen both for adults (Cockcroft-Gault [C-G] and Modification of Diet in Renal Disease [MDRD] study equations) and for children (Schwartz and Counahan-Barratt equations). This review aims to evaluate from recent literature the clinical efficiency and relevance of these equations in terms of bias, precision, and reproducibility in different specific indications (eg, screening CKD, assessment of disease progression, or therapy efficacy) in different populations. Because these prediction equations based on serum creatinine have limitations, especially in the normal or near-normal GFR range, kidney transplant recipients, and pediatric populations, other prediction equations based on serum cystatin C value were also considered as possibly more sensitive GFR surrogate markers. Recent guidelines state that the cystatin C-based prediction equation cannot be recommended for use in clinical practice. With prediction equations based on serum creatinine, the National Kidney Disease Education Program (NKDEP) recommendations are to report a numerical estimate in round numbers only for GFR values <60 mL/min per 1.73 m(2). The MDRD equation generally outperforms the C-G equation but may still have a high level of bias, depending on creatinine assay calibration, and low precision with, at best, approximately 80% of estimated GFR in the "accuracy range" of 70-130% of the measured GFR value, even in patients with known CKD. According to Kidney Disease Improving Global Outcomes (KDIGO) recommendations, many indications remain for GFR measurements using a clearance method. In that context, it should be recalled that radiolabeled-tracer plasma or urinary clearance methods, are safe, simple, accurate and reproducible.
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PMID:Monitoring renal function and limitations of renal function tests. 1809 62

Posterior urethral valves are the main cause of fetal lower urinary tract obstruction (LUTO) with typical sonographic signs like urinary tract dilatation and reduction of amniotic fluid. LUTO is associated with a high rate of perinatal mortality and is the main cause of kidney failure in early childhood. In such cases vesico-amniotic shunting is a common but risky procedure of fetal surgery to prevent anhydramnion and lethal lung hypoplasia. This case report demonstrates that lung hypoplasia can be prevented by vesico-amniotic shunting of the fetal megacytis in the 23rd week of gestation in a fetus with lower urinary tract obstruction and anhydramnion. The prenatal measured concentration of cystatin C in the fetal urine correlated with the postnatal impaired kidney function. The indication and therapeutic benefit of vesico-amniotic shunting remain controversially discussed in the literature because until today there is no evidence for a reduction in perinatal or long-term morbidity due to early fetal kidney damage. The earlier ultrasound detection of LUTO during the first trimester of pregnancy proposes the possibility of earlier intervention and protection of nephrogenesis. First case studies about first trimester vesico-amniotic shunting have been published; the influence on the postnatal kidney function merits further well-structured investigation.
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PMID:[Feto-amniotic shunting for lower urinary tract obstruction (LUTO)--a case report]. 1817 6

Acute renal failure (ARF) is an acute loss of kidney function that occurs over days to weeks and results in an inability to appropriately excrete nitrogenous wastes and creatinine (Cre). ARF is diagnosed by elevations of blood urea nitrogen and serum Cre level, which is classified as prerenal, intrinsic and postrenal according to their mechanisms. However, discriminate diagnosis of these types by blood biochemistry findings is difficult. Recently, cystatin C (Cys-C), a basic protein having isoelectric point 9.3 with a molecular weight of 13.3 kDa, is freely filtered at the level of the glomerulus and virtually all is reabsorbed and metabolized by the proximal tubular cells. Therefore, assuming constant cellular production, serum Cys-C level has the potential to be an excellent surrogate marker of glomerular filtration rate. Because Cre is electrically charged neutrally, there is a possibility that the permeation of Cys-C, which is positively charged, is diffluent from that of Cre through glomerular basement membrane due to the type of the renal failure. We determined blood concentrations of Cys-C and Cre in a patients with prerenal renal failure (17 patients), intrinsic renal failure (232 patients) and postrenal renal failure (13 patients) as compared with healthy subjects (n = 771). We found that patients with postrenal renal failure displayed significantly elevated Cre/Cys-C ratio (mean +/- standard deviation) (8.3 +/- 8.0, p < 0.001) as compared with healthy subjects (1.1 +/- 0.2), prerenal (0.6 +/- 0.2) and intrinsic (1.6 +/- 0.5). These findings suggest that measurement of Cys-C concentration and Cre/Cys-C ratio may be useful for the discriminate diagnosis of postrenal renal failure.
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PMID:[Plasma creatinine and cystatin C ratio is useful for discriminate diagnosis of postrenal renal failure]. 1840 24

Acute and especially chronic renal failure (CRF) are relatively common and important risk factor for morbidity and mortality in patients after heart, lung, liver or intestine transplantation. Numerous factors contribute to the development of CRF in this group of patients, like treatment with calcineurin inhibitors and other nephrotoxic drugs in the perioperative period, hemodynamical changes during and after the surgery, preexistent renal disease, hypertension, diabetes mellitus, dyslipidemia and anemia. Pretransplant evaluation of renal function is mandatory to predict which patients have increased risk for development of CRF. In the posttransplantation course it is necessary to timely diagnose and treat renal failure, while patients with insufficient renal function have 4.55-fold increased risk of death compared to patients with normal renal function. Special problem is diagnostic approach to patients with suspected chronic renal disease who are candidates for transplantation of other parenhimatose organs. Diagnostic value of serum creatinine and estimation of renal function based on its value is very limited. Gold diagnostic standard is radioisotope estimation of glomerular filtration, but this method is not widely available. It seems that this problem may be solved with the use of cystatin C, but this approach needs to be validated in large studies. Numerous different immunosuppressive drugs available on the market enable individualization of immunosuppression. Different drugs combinations may have less nephrotoxic potential, but one must be careful because of the possible risk of organ rejection with the change of immunosuppression. Use of angiotensin convertase enzyme inhibitors and/or angiotensin receptor blockers, statins with drugs for control of hyperglycemia, may prevent or postpone development of CRF. Although technical advances of contemporary hemodialysis machines and peritoneal dialysis equipment enable well tolerated dialysis even in critically ill patients, renal transplantation remains the method of choice for treatment of patients with transplanted parenhimatous organ that developed CRF.
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PMID:[Chronic renal failure after heart, lung, liver, or intestine transplantation]. 1857 34

As the US population has continued to age, the number of patients with chronic kidney disease (CKD) has dramatically increased. Faced with this increase, clinicians need a better understanding of what an elevated serum creatinine level represents and a simple codified approach to evaluating renal failure. Creatinine, a muscle waste product, has an imperfect but predictable association with the glomerular filtration rate (GFR). Although other markers of GFR exist, including cystatin C, urea, inulin, and radioisotopic methods, their role in estimating GFR remains a matter for debate, especially that of cystatin C. Diagnosis and management of CKD are challenges for the nonspecialist. We describe a systematic approach that can be used by the nonspecialist to identify most but not all causes of renal insufficiency. Although this approach should allow for earlier recognition of treatable causes of CKD, it does not eliminate the involvement of a nephrologist in the care and management of the conditions causing the renal insufficiency. The nonspecialist should also be able to recognize the 9 therapies that are helpful in preservation of renal function in all patients with CKD.
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PMID:Diagnosis and management of chronic kidney disease. 1877 6


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