| 1. |
- Christensson, Anders, et al.
(författare)
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Serum cystatin C advantageous compared with serum creatinine in the detection of mild but not severe diabetic nephropathy.
- 2004
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Ingår i: Journal of Internal Medicine. - : Wiley. - 1365-2796 .- 0954-6820. ; 256:6, s. 510-518
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine whether serum cystatin C is more accurate than serum creatinine in the detection of diabetic nephropathy, also after adjustment for age.METHODS: Forty-one patients with type 1 and 82 patients with type 2 diabetes were evaluated with serum creatinine, serum cystatin C, and (51)Cr-EDTA clearance (reference method). Cystatin C was measured by a particle-enhanced turbidimetric method and creatinine by an enzymatic method. Statistical estimations were performed both without and with age adjustment created by z-scores for (51)Cr-EDTA clearance, creatinine, and cystatin C. The cut-off levels for glomerular filtration rate (GFR) ((51)Cr-EDTA clearance) were 60 and 80 mL min(-1) 1.73 m(-2), respectively, in absolute values and 80, 90 and 95% CIs, respectively, in age-adjusted values (z-scores).RESULTS: Estimations without age adjustment showed significantly (P = 0.0132) closer correlation for cystatin C (r = 0.817) versus (51)Cr-EDTA clearance as compared with creatinine (r = 0.678). However, when using age-adjusted values, the correlation for cystatin C and creatinine, respectively, versus (51)Cr-EDTA clearance did not differ. When comparing the diagnostic utilities for serum cystatin C versus serum creatinine in manifest renal impairment (GFR < 60 mL min(-1) 1.73 m(-2) or z-scores <-1.28 SD), there were no significant differences between the two markers whether age adjusted or not. However, for diagnosing mild nephropathy (GFR < 80 mL min(-1) 1.73 m(-2) or z-score -0.84 SD), serum cystatin C is significantly more useful.CONCLUSIONS: Serum cystatin C performed better compared with serum creatinine even when measured enzymatically, to detect mild diabetic nephropathy. However, serum creatinine was as efficient as serum cystatin C to detect advanced diabetic nephropathy.
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| 2. |
- Christensson, Anders, et al.
(författare)
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Serum cystatin C is a more sensitive and more accurate marker of glomerular filtration rate than enzymatic measurements of creatinine in renal transplantation.
- 2003
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Ingår i: Nephron Physiology. - : S. Karger AG. - 1660-2137. ; 94:2, s. 19-27
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Tidskriftsartikel (refereegranskat)abstract
- <i>Background/Aims:</i> Serum creatinine has several drawbacks as marker of glomerular filtration rate (GFR), and therefore serum cystatin C has been proposed as a more optimal GFR marker. Previous reports have suggested benefits of serum cystatin C measurements in patients with renal transplants. The purpose of the present study was to evaluate the diagnostic accuracy of cystatin C measurements compared with enzymatic creatinine measurements as serum markers of GFR (established from plasma clearance of iohexol) in a large cohort of stable renal transplant recipients and in the early postoperative phase. <i>Methods:</i> Renal transplant patients (n = 125) with stable graft function were evaluated from reciprocals of serum creatinine and cystatin C compared with iohexol clearance. Fourteen patients were examined immediately after the onset of renal function. Cystatin C was measured by a particle-enhanced turbidimetric method and creatinine by an enzymatic method. <i>Results:</i> In stable renal transplant recipients, serum cystatin C showed a significantly (p = 0.033) closer correlation (r = 0.89 or 79% co-variance) with iohexol clearance than did serum creatinine (r = 0.81 or 66% co-variance). Using the χ<sup>2</sup> test and a cut-off at 60 ml/min/1.73 m<sup>2</sup>, serum cystatin C levels demonstrated significantly higher sensitivity for early GFR impairment (p = 0.0045) compared with serum creatinine measurements. On the first day after transplantation, serum cystatin C fell more rapidly than serum creatinine. <i>Conclusion:</i> Serum cystatin C levels correlate significantly closer to accurate measurements of GFR and are significantly more sensitive to detect early GFR impairment than enzymatic measurements of creatinine in serum.
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| 3. |
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| 4. |
- Grubb, Anders, et al.
(författare)
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Simple Cystatin C-Based Prediction Equations for Glomerular Filtration Rate Compared with the Modification of Diet in Renal Disease Prediction Equation for Adults and the Schwartz and the Counahan-Barratt Prediction Equations for Children.
- 2005
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Ingår i: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 51:8, s. 1420-1431
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Serum creatinine is the most commonly used marker for estimation of glomerular filtration rate (GFR). To compensate for its drawbacks as a GFR marker, several prediction equations including several parameters are being used, with the Modification of Diet in Renal Disease (MDRD), Schwartz, and Counahan-Barratt equations being the ones most widely accepted for estimation of relative GFR in mL x min(-1) x (1.73 m(2))(-1). The present study analyzes whether these GFR prediction equations for adults and children might be replaced by simple prediction equations based on plasma concentrations of cystatin C.METHODS: Data from 536 patients (0.3-93 years), consecutively referred for determination of GFR by an invasive gold standard procedure, were used for the analysis. Calculations of bias (median percentage of error), correlation (adjusted R(2)), and percentage of estimates within 30% and 50% of measured GFR were used in the comparisons.RESULTS: A cystatin C-based prediction equation using only concentration in mg/L and a prepubertal factor: GFR [mL x min(-1) x (1.73 m(2))(-1)] = 84.69 x cystatin C (mg/L)(-1.680) x 1.384 (if a child <14 years) assessed GFR equally well or better than the simplified MDRD, the Schwartz, and the Counahan-Barratt prediction equations for the adult (> or =18 years) and juvenile groups of the investigated cohort. Age did not influence the cystatin C-based prediction equation for adults, whereas gender did, but with a factor close to unity (0.948 for females).CONCLUSION: A GFR prediction equation based solely on cystatin C (in mg/L) and a prepubertal factor might replace the simplified MDRD prediction equation for adults and the Schwartz and Counahan-Barratt prediction equations for children.
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| 5. |
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| 6. |
- Lindström, Veronica, et al.
(författare)
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Different elimination patterns of beta-trace protein, beta(2)-microglobulin and cystatin C in haemodialysis, haemodiafiltration and haemofiltration.
- 2008
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Ingår i: Scandinavian Journal of Clinical & Laboratory Investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 68, s. 685-691
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Low molecular mass proteins (LMMP) are putative uraemic toxins, but their elimination is negligible in standard haemodialysis (HD). In this study, we used beta(2)-microglobulin, cystatin C and beta-trace protein, which differ in molecular mass and charge, to characterize the elimination patterns of three different dialysis modalities. Material and methods. Plasma samples were obtained at the start, 30 min after the start, at the end of the dialysis treatment and 30 min after termination of the dialysis session. Seventeen patients were treated with low-flux HD, 13 with post-dilution haemodiafiltration (HDF) and 8 with pre-dilution haemofiltration (HF). The changes in concentrations of the three LMMPs were monitored and expressed as percentages of the concentrations at the start of treatments. Results. Conventional HD with low-flux membranes showed a high elimination of small molecules (urea and creatinine), but did not reduce the levels of the three LMMPs studied. During HDF and HF, there was a significant decrease in the plasma levels of cystatin C (to 28 % and 44 %, respectively) (p<0.001) and of beta(2)-microglobulin (to 23 % and 33 %, respectively) (p<0.001). However, the level of beta-trace protein was significantly reduced (to 65 %) only after HDF. Conclusions . The three dialysis modalities showed significantly different elimination patterns for the LMMPs studied. Elimination of beta-trace protein was lower than those of cystatin C and beta(2)-microglobulin both in HDF and HF. beta-trace protein was only moderately eliminated by HDF and not at all by HF, and may be a useful marker in the evaluation of different convective therapies.
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| 7. |
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| 8. |
- Alfvén, Tobias, et al.
(författare)
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Low-level cadmium exposure and osteoporosis.
- 2000
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Ingår i: Journal of Bone and Mineral Research. - 0884-0431 .- 1523-4681. ; 15, s. 1579-1586
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis is a major cause of morbidity worldwide. A number of risk factors, such as age and gender, are well established. High cadmium exposure causes renal damage and in severe cases also causes osteoporosis and osteomalacia, We have examined whether long-term Pow-level cadmium exposure increases the risk of osteoporosis. Bone mineral density (BMD) in the forearm was measured in 520 men and 544 women, aged 16-81 years, environmentally or occupationally exposed to cadmium, using dual-energy X-ray absorptiometry (DXA) technique. Cadmium in urine was used as the dose estimate and protein HC was used: as a marker of renal tubular damage. There was a clear dose-response relation between cadmium dose and the prevalence of tubular proteinuria. Inverse relations were found between cadmium dose, tubular proteinuria, and BMD, particularly apparent in persons over 60 years of age, There was a dose-response relation between cadmium dose and osteoporosis. The odds ratios (ORs) for men were 2.2 (95% CI, 1.0-4.8) in the dose group 0.5-3 nmol Cd/mmol creatinine and 5.3 (2.0-14) in the highest dose category (greater than or equal to 3 nmol/mmol creatinine) compared with the lowest dose group (<0.5 nmol Cd/mmol creatinine). For women, the OR was 1.8 (0.65-5.3) in the dose group 0.53 nmol Cd/mmol creatinine. We conclude that exposure to low levels of cadmium is associated with an increased risk of osteoporosis.
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| 9. |
- Bakoush, Omran, et al.
(författare)
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Inaccuracy of GFR predictions by plasma cystatin C in patients without kidney dysfunction and in advanced kidney disease.
- 2008
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Ingår i: Clinical Nephrology. - 0301-0430. ; 69:5, s. 331-338
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Tidskriftsartikel (refereegranskat)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 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.
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| 10. |
- Bakoush, Omran, et al.
(författare)
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Urine excretion of protein HC in proteinuric glomerular diseases correlates to urine IgG but not to albuminuria
- 2001
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Ingår i: Kidney International. - : Elsevier BV. - 1523-1755 .- 0085-2538. ; 60:5, s. 1904-1909
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Proteinuric glomerular diseases often are associated with tubulointerstitial injury, which imposes on the progression of renal failure. Tubular damage is partly referable to toxic effects on the tubular epithelial cells induced by filtered plasma proteins. Patients with nonselective proteinuria, that is, increased urine excretion of high-molecular-weight plasma proteins such as IgG in comparison to albumin, often have poor renal outcome. The present observational study examined correlations between the degree of tubular damage, measured by urine concentration of protein HC, and the levels of urine IgG and albuminuria. METHODS: Measurements of urine concentrations of IgG, albumin, and protein HC were performed in 56 proteinuric patients (33 males and 23 females) with nondiabetic glomerular diseases at the time of the diagnostic renal biopsy and at a mean of 49 follow-up months. RESULTS: A highly significant correlation between the urine IgG excretion and the urine protein HC concentration was found both at the start and at the end of the observational time (r = 0.74 and 0.65, respectively, P < 0.001). Furthermore, alterations in the urinary excretion of the two proteins in single patients correlated significantly to each other (r = 0.84, P < 0.001). The correlation between the degree of albuminuria and the protein HC excretion was significant at the time of kidney biopsy, but ceased to exist during the follow-up time. Stepwise linear regression analysis showed that in comparison with the creatinine clearance and albuminuria, only the changes in urinary IgG excretion were related to the corresponding changes in urinary protein HC excretion (r = 0.84 and r2 = 0.7, P < 0.001). CONCLUSION: The findings of the study suggest that the urinary protein HC concentration correlates to the degree of IgG-uria but not to the degree of albuminuria during the course of proteinuric glomerular disease. Whether this correlation is to be explained by an intrinsic toxic effect on tubular cells executed by IgG or perhaps by some other high molecular weight proteins, needs to be investigated further. However, the results contribute to the understanding of the poor renal survival in patients with glomerular diseases and nonselective proteinuria.
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