scholarly journals Adult Reference Ranges for Serum Cystatin C, Creatinine and Predicted Creatinine Clearance

Author(s):  
Hazel Finney ◽  
David J Newman ◽  
Christopher P Price

Serum cystatin C measurement has been previously shown by ourselves and others to be a better indicator of changes in glomerular filtration rate (GFR) than serum creatinine. However, the available literature on reference values for cystatin C concentration remains surprisingly sparse; we thus set out to determine an adult reference range. Blood was taken from 309 healthy blood donors and creatinine and cystatin C concentrations were measured using commercially available automated methodologies. In addition, predicted creatinine clearances were calculated using the Cockcroft and Gault formula. The 95% reference intervals for creatinine, predicted creatinine clearance and cystatin C for all blood donors, regardless of gender, were 68–118 μmol/L, 58–120 ml/min/1·73 m2 and 0·51–0·98 mg/L, respectively. For women, the intervals were 68–98 μmol/L, 60–119 ml/min/1·73 m2 and 0·49–0·94 mg/L; for men, they were 78–123 μmol/L, 57–122 ml/min/1·73 m2 and 0·56–0·98 mg/L. The mean 95% reference interval for cystatin C in all donors under 50 years of age was 0·53–0·92 mg/L; for those over 50 years of age it was 0·58–1·02 mg/L. The small difference between male and female ranges meant that a single reference range for cystatin C could be established for all adults under 50 years of age without adjustment for body surface area. Serum cystatin C measurement offers a simpler and more sensitive screening test than serum creatinine for early changes in GFR.

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Bertille Elodie Edinga-Melenge ◽  
Adrienne Tchapmi Yakam ◽  
Jobert Richie Nansseu ◽  
Catherine Bilong ◽  
Suzanne Belinga ◽  
...  

2019 ◽  
Author(s):  
Chao Tong ◽  
Yalan Liu ◽  
Yanqiu Wu ◽  
Qiong Li ◽  
Yipin Wu ◽  
...  

Abstract Backgroud : To establish reference values of serum cystatin C (CysC) in Chinese newborn infants. Methods: Serum CysC levels were measured in 1919 blood samples from 1044 newborns during their first 28 days of life. CysC levels were analyzed for association between subgroups dichotomized by postnatal age (PA) and gestational age (GA). Reference intervals of serum CysC were determined according to the PA and GA. The association between serum CysC level and other biochemical parameters as well as perinatal factors were also analyzed. Results: In this study, the mean GA was 35.75±2.90 weeks and birth weight was 2613.77±696.72 g. Reference ranges of serum CysC were determined and a general decreasing trend of CysC levels was observed as GA increased. CysC levels differed significantly among the PA and GA groups (P<0.001). Serum CysC levels were relatively stable throughout GA, except being impacted by white blood cell count within postnatal 24 hours. Moreover, their levels always correlated positively with serum creatinine concentrations (P<0.001). Conclusion: The reference level of serum CysC should be determined according to PA and GA. In contrast to creatinine, serum CysC is a dependable index for assessing renal function in neonate, for there are rare factors influencing it.


2000 ◽  
Vol 46 (2) ◽  
pp. 193-197 ◽  
Author(s):  
Borut Štabuc ◽  
Levin Vrhovec ◽  
Mirna Štabuc-Šilih ◽  
Tomaž Edvard Cizej

Abstract Background: Serum cystatin C, a cysteine protease inhibitor, has been suggested as a new marker of glomerular filtration rate (GFR). This study explored the possibility of replacing the creatinine clearance (CrCl) estimation of GFR with cystatin C in early detection of renal impairment in cancer patients on chemotherapy. Methods: Serum creatinine and cystatin C concentrations as well as 24-h CrCl were determined simultaneously in 72 cancer patients. Among them, 60 were treated with combined chemotherapy with cisplatin (CDDP). Creatinine was determined enzymatically with a spectrophotometric method. Serum cystatin C was determined by a particle-enhanced turbidimetric immunoassay. Results: Cystatin C and creatinine correlated significantly (P = 0.001) with CrCl. The correlation was significantly better for cystatin C than creatinine (r = 0.84 vs 0.74; P = 0.01). Stepwise regression analysis identified no differences for the correlations between cystatin C and CrCl in patients with or without metastases (r = 0.82 and 0.84, respectively) as well as before treatment and before the fourth cycle of chemotherapy (r = 0.70 and 0.75, respectively). A cystatin C cutoff concentration of 1.33 mg/L had 87% sensitivity and 100% specificity for detecting CrCl &lt;78 mL/min. ROC analysis indicated that cystatin C was superior to serum creatinine for predicting CrCl &lt;78 mL/min (P &lt;0.04). Conclusions: Serum cystatin C is superior to serum creatinine for detection of decreased CrCl and potentially for the estimation of GFR in cancer patients independent of the presence of metastases or chemotherapy.


Author(s):  
Shelagh E O'Riordan ◽  
Michelle C Webb ◽  
Helen J Stowe ◽  
David E Simpson ◽  
Madhu Kandarpa ◽  
...  

Background: Conventional estimates of glomerular dysfunction, including serum creatinine and creatinine clearance, are inadequate in older people. In this study we have compared the diagnostic accuracy of a novel test of kidney disease, cystatin C, against these markers in older patients with a range of renal function. Methods: Fifty-three patients (mean age 79.6 years, range 69-92 years) with a variety of medical diagnoses were recruited via outpatient clinics. Exclusion criteria included active rheumatoid disease, known current malignancy, renal replacement therapy/renal transplantation and cognitive impairment. 51Cr-EDTA was used as the reference method against which the other markers of glomerular filtration rate were compared using regression analyses. Results: The best fit with glomerular filtration rate was given by Cockcroft and Gault calculated clearance ( R2 = 0.83), followed by serum cystatin C ( R2 = 0.79), serum creatinine ( R2 = 0.76) and creatinine clearance ( R2 = 0.73). The accuracy for glomerular filtration rate prediction was poor for all markers. Serum cystatin C detected nearly all patients with mild renal impairment whereas serum creatinine only detected half of these cases. Regression modelling predicted that the upper limit of normal for serum cystatin C would be exceeded as glomerular filtration rate fell below 64 mL/min/1.73 m2, compared with 44 mL/min/1.73 m2 for serum creatinine. Conclusion: Serum cystatin C is a simple and sensitive screening test for kidney dysfunction in older people.


1998 ◽  
Vol 44 (7) ◽  
pp. 1535-1539 ◽  
Author(s):  
Brian G Keevil ◽  
Eric S Kilpatrick ◽  
Simon P Nichols ◽  
Paul W Maylor

Abstract To assess the inherent potential for detecting mild to moderate reductions in glomerular filtration rate, this study determined the biological variability of serum cystatin C and creatinine in 12 healthy subjects. After accounting for analytical variation, interindividual variance accounted for 93% and intraindividual variance accounted for 7% of serum creatinine biological variation. As such, to lie outside the assay reference interval, some subjects must exceed 13 SD from their usual mean value, whereas in others, a change of only 2 SD would be sufficient. For cystatin C, interindividual variation explained 25% and intraindividual variance explained 75% of biological variability. Therefore, the upper limit of the population reference interval for cystatin C is seldom more than 3–4 SD from the mean value of any healthy individual. The critical difference for sequential values significant at P ≤0.05 was calculated as 37% for serum cystatin C and 14% for serum creatinine. We conclude that cystatin C is potentially a better marker for detecting impaired renal function than serum creatinine, but serum creatinine is probably still the better marker for detecting temporal changes of renal function in individuals with established renal disease.


Author(s):  
Margaret A. Jenkins ◽  
Douglas J. Brown ◽  
Francesco L. Ierino ◽  
Sujiva I. Ratnaike

Background: Serum creatinine is not a satisfactory marker of glomerular filtration rate (GFR) in patients with spinal cord injury (SCI) who have varying degrees of muscle atrophy. In contrast to serum creatinine, serum cystatin C, a 13-kDa protein, is not affected by muscle mass and is therefore potentially a useful marker of GFR in patients with SCI. In addition, cystatin C is not dependent on sex or age and is not secreted by the renal tubule. Aim: We assessed serum cystatin C as a surrogate marker of GFR in SCI patients. Methods: Cystatin C was analysed using a particle-enhanced immunonephelometric assay (Dade Behring) in serum samples sent for routine measurement of creatinine (64 patients) and creatinine clearance (27 patients) from patients in the Spinal Unit of the Austin Health. We compared these results with serum cystatin C of 57 non-SCI patients who had had a creatinine clearance measurement during the study period. Results: In patients with SCI, the reciprocal of cystatin C had a stronger correlation (r = 0·48, P<0·01) with creatinine clearance than the reciprocal of serum creatinine (r = 0·25, P<0·19). Further, the value of serum creatinine was much lower for a given creatinine clearance in SCI patients than in non-SCI patients; the serum cystatin C concentrations were equivalent. Conclusion: The serum cystatin C is a convenient and more reliable surrogate marker of GFR than serum creatinine and will enable early detection of renal impairment. We need to confirm this finding with a larger study, including comparison with an accepted gold standard for GFR.


2019 ◽  
Vol 68 (3) ◽  
pp. 15-24 ◽  
Author(s):  
Natalia V. Borovik ◽  
Maria I. Yarmolinskaya ◽  
Olga B. Glavnova ◽  
Alyona V. Tiselko ◽  
Svetlana V. Suslova ◽  
...  

Hypothesis/aims of study. Using early non-invasive markers of diabetic nephropathy (DN) in clinical practice is important to early start of nephroprotective therapy and leads to improving the quality of life, while decreasing disability and mortality of diabetic patients. The aim of the study was to estimate the potential of using serum cystatin C and glomerular filtration rate (GFR) calculated by CKD-EPIcys and CKD-EPIcr-cys equations for an early diagnosis of DN in type 1 diabetic (T1D) women who were planning pregnancy or were in the I trimester of pregnancy. Study design, materials, and methods. 47 T1D women were examined, of whom 25 individuals were pregnant and 22 ones were planning pregnancy. In all patients, glycated hemoglobin and serum cystatin C levels were determined, GFR was estimated by the creatinine clearance test, MDRD, CKD-EPIcr, CKD-EPIcys, and CKD-EPIcr-cys equations, with diabetes training done. Results. The pregnant group and the planning pregnancy group were distinguished by glycated hemoglobin (p = 0.001), serum creatinine (p = 0.001), and GFR estimated by the creatinine clearance test (р = 0.017), CKD-EPIcr (р = 0.005), and CKD-EPIcr-cys (р = 0.046) equations. There was no difference in urinary creatinine, serum cystatin C, and GFR estimated by CKD-EPIcys equation and daily urinary protein excretion between the study groups. Most pregnant women (87.5%) were in stage C1 and only 12,5% in stage C2 as determined by estimated GFR using the CKD-EPIcr formula, which was significantly different compared to the planning pregnancy group, where the percentage of women in stages C1 and C2 was comparable (р = 0.002). In addition, most pregnant patients were in stage C1, while most of the patients planning pregnancy were referred to stage C2 by GFR estimated by CKD-EPIcysequation. Stage C3a was diagnosed in the both study groups only when CKD-EPIcys equation for GFR estimation was used. Most women from both groups were in stage C1 when GFR was estimated by the creatinine clearance test, the percentage ratio of patients in stages C1 and C2 in both groups being comparable. Conclusion. Our results demonstrated that serum cystatin C and GFR estimation by CKD-EPIcys equation could improve nephropathy diagnostic accuracy among T1D patients with a normal serum creatinine level and intact GFR based on creatinine level.


Author(s):  
Sudarshan N. Shelke ◽  
Jyoti S. Tele

Background: Diabetic kidney disease is the leading cause of premature death in young diabetic patients. Detection of diabetic kidney disease as early as possible in the disease process currently offers the best chance of delaying or possibly preventing progression to end-stage renal disease. The present study was aimed to evaluate utility of serum cystatin C based eGFR for early diagnosis of diabetic kidney disease.Methods: Diagnosed patients of type 2 diabetes mellitus having frank proteinuria were excluded. Patients without proteinuria were tested for microalbuminuria.  50 patients having microalbuminuria were tested for 24 hour urine creatinine, serum creatinine and serum cystatin C. Both cystatin C based eGFR and eGFR by Cockcroft and Gault equation were compared with standard GFR by 24 hour urine Creatinine clearance respectively.Results: There was statistically significant positive correlation between cystatin C based eGFR and standard GFR by 24 hr Creatinine clearance (r=0.87). For eGFR by Cockcroft-Gault equation, it was 0.36 (r=0.36).Conclusions: The results of this study suggest that serum cystatin C based eGFR  measurement is a useful, practical tool for the evaluation of renal involvement in the course of diabetes. As serum creatinine values are affected by many factors like age, sex, muscle mass and diet, serum cystatin C based eGFR estimation offers a hope that diabetic kidney disease can be well prevented with appropriate interventions.


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