Biological variation data for kidney function related parameter: serum beta trace protein, creatinine and cystatin C from 22 apparently healthy Turkish subjects

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Anil Baysoy ◽  
Inanc Karakoyun ◽  
Fatma Demet Arslan ◽  
Banu Isbilen Basok ◽  
Ayfer Colak ◽  
...  
Keyword(s):  
Serum Creatinine ◽  
Cystatin C ◽  
Biological Variation ◽  
Reference Ranges ◽  
Disease Dynamics ◽  
Single Session ◽  
Nephelometric Method ◽  
Reference Change Value ◽  
Variation Data ◽  
Apparently Healthy

Abstract Objectives Biological variation is defined as the variation in analytical concentration between and within individuals, and being aware of this biological variation is important for understanding disease dynamics. The aim of our study is to calculate the within-subject (CVI) and between-subject (CVG) biological variations of serum creatinine, cystatin C and Beta trace protein (BTP), as well as the reference change value (RCV) and individuality indexes (II), which are used to calculate the glomerular filtration rate while evaluating kidney damage. Methods Blood samples were collected from 22 healthy volunteers for 10 consecutive weeks and stored at −80 °C until the day of analysis. While the analysis for serum creatinine was performed colorimetrically with the kinetic jaffe method, the nephelometric method was employed for cystatin C and BTP measurements. All analyses were carried out in a single session for each test. Results Analytical coefficient of variation (CVA) for serum creatinine, cystatin C and beta trace protein was 5.56, 3.48 and 5.37%, respectively. CVI and CVG: for serum creatinine: 3.31, 14.50%, respectively, for cystatin C: 3.15, 12.24%, respectively, for BTP: 9.91, 14.36%, respectively. RCV and II were calculated as 17.94%, 0.23 for serum creatinine, 13.01%, 0.26 for cystatin C, 31.24%, 0.69 for BTP, respectively. Conclusions According to the data obtained in our study, serum creatinine and cystatin C show high individuality, therefore we think that the use of RCV instead of reference ranges would be appropriate. Although II is found to be low for BTP, more studies are needed to support this finding.

scholarly journals Biological Variation of Vitamins in Blood of Healthy Individuals

2005 ◽  
Vol 51 (11) ◽  
pp. 2145-2150 ◽  
Author(s):  
Dinesh K Talwar ◽  
Mohammed K Azharuddin ◽  
Cathy Williamson ◽  
Yee Ping Teoh ◽  
Donald C McMillan ◽  
...  
Keyword(s):  
Whole Blood ◽  
Total Error ◽  
Reference Intervals ◽  
Biological Variation ◽  
Reference Change Value ◽  
Objective Quality ◽  
Variation Data ◽  
Quality Specifications ◽  
Index Of Individuality ◽  
Apparently Healthy

Abstract Background: Components of biological variation can be used to define objective quality specifications (imprecision, bias, and total error), to assess the usefulness of reference values [index of individuality (II)], and to evaluate significance of changes in serial results from an individual [reference change value (RCV)]. However, biological variation data on vitamins in blood are limited. The aims of the present study were to determine the intra- and interindividual biological variation of vitamins A, E, B1, B2, B6, C, and K and carotenoids in plasma, whole blood, or erythrocytes from apparently healthy persons and to define quality specifications for vitamin measurements based on their biology. Methods: Fasting plasma, whole blood, and erythrocytes were collected from 14 healthy volunteers at regular weekly intervals over 22 weeks. Vitamins were measured by HPLC. From the data generated, the intra- (CVI) and interindividual (CVG) biological CVs were estimated for each vitamin. Derived quality specifications, II, and RCV were calculated from CVI and CVG. Results: CVI was 4.8%–38% and CVG was 10%–65% for the vitamins measured. The CVIs for vitamins A, E, B1, and B2 were lower (4.8%–7.6%) than for the other vitamins in blood. For all vitamins, CVG was higher than CVI, with II <1.0 (range, 0.36–0.95). The RCVs for vitamins were high (15.8%–108%). Apart from vitamins A, B1, and erythrocyte B2, the imprecision of our methods for measurement of vitamins in blood was within the desirable goal. Conclusions: For most vitamin measurements in plasma, whole blood, or erythrocytes, the desirable imprecision goals based on biological variation are obtainable by current methodologies. Population reference intervals for vitamins are of limited value in demonstrating deficiency or excess.

scholarly journals The EuBIVAS Project: Within- and Between-Subject Biological Variation Data for Serum Creatinine Using Enzymatic and Alkaline Picrate Methods and Implications for Monitoring

2017 ◽  
Vol 63 (9) ◽  
pp. 1527-1536 ◽  
Author(s):  
Anna Carobene ◽  
Irene Marino ◽  
Abdurrahman Coşkun ◽  
Mustafa Serteser ◽  
Ibrahim Unsal ◽  
...  
Keyword(s):  
Serum Creatinine ◽  
Clinical Chemistry ◽  
Biological Variation ◽  
European Federation ◽  
Healthy Individuals ◽  
Homogeneity Analysis ◽  
Variation Data ◽  
Performance Specifications ◽  
Age Range ◽  
Analytical Variation

Abstract BACKGROUND The European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) European Biological Variation Study (EuBIVAS) has been established to deliver rigorously determined biological variation (BV) indices. EuBIVAS determined BV for serum creatinine using the enzymatic and alkaline picrate measurement methods. METHOD In total, 91 healthy individuals (38 males, 53 females; age range, 21–69 years) were bled for 10 consecutive weeks at 6 European laboratories. An equivalent protocol was followed at each center. Sera were stored at −80 °C before analysis. Analyses for each patient were performed in duplicate within a single run on an ADVIA 2400 system (San Raffaele Hospital, Milan). The data were subjected to outlier and homogeneity analysis before performing CV-ANOVA to determine BV and analytical variation (CVA) estimates with confidence intervals (CI). RESULTS The within-subject BV estimates [CVI (95% CI)] were similar for enzymatic [4.4% (4.2–4.7)] and alkaline picrate [4.7% (4.4–4.9)] methods and lower than the estimate presently available online (CVI = 5.9%). No significant male/female BV differences were found. Significant differences were observed in mean creatinine values between men and women and between Turkish individuals and those of other nationalities. Between-subject BV (CVG) estimates, stratified accordingly, produced CVG values similar to historical BV data. CVA was 1.1% for the enzymatic and 4.4% for alkaline picrate methods, indicating that alkaline picrate methods fail to fulfill analytical performance specifications for imprecision (CVAPS). CONCLUSIONS The serum creatinine CVI obtained by EuBIVAS specifies a more stringent CVAPS than previously identified. The alkaline picrate method failed to meet this CVAPS, raising questions regarding its future use.

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

2000 ◽  
Vol 37 (1) ◽  
pp. 49-59
Author(s):  
Hazel Finney ◽  
David J Newman ◽  
Christopher P Price
Keyword(s):  
Serum Creatinine ◽  
Creatinine Clearance ◽  
Cystatin C ◽  
Blood Donors ◽  
Reference Range ◽  
Reference Interval ◽  
Reference Intervals ◽  
Reference Ranges ◽  
Serum Cystatin C ◽  
Serum Cystatin

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.

scholarly journals Reference intervals for serum cystatin C and serum creatinine in an adult sub-Saharan African population

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Bertille Elodie Edinga-Melenge ◽  
Adrienne Tchapmi Yakam ◽  
Jobert Richie Nansseu ◽  
Catherine Bilong ◽  
Suzanne Belinga ◽  
...  
Keyword(s):  
Serum Creatinine ◽  
Cystatin C ◽  
Reference Intervals ◽  
African Population ◽  
Serum Cystatin C ◽  
Serum Cystatin ◽  
Sub Saharan

scholarly journals Critical appraisal and meta-analysis of biological variation studies on glycosylated albumin, glucose and HbA1c

2020 ◽  
Vol 1 (3) ◽  
Author(s):  
Carmen Ricós ◽  
Pilar Fernández-Calle ◽  
Elisabet Gonzalez-Lao ◽  
Margarida Simón ◽  
Jorge Díaz-Garzón ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Critical Appraisal ◽  
Meta Analysis ◽  
Biological Variation ◽  
Evidence Based ◽  
Literature Searches ◽  
Variation Data ◽  
Global Estimates ◽  
Systematic Literature Searches

AbstractObjectivesNumerous biological variation (BV) studies have been performed over the years, but the quality of these studies vary. The objectives of this study were to perform a systematic review and critical appraisal of BV studies on glycosylated albumin and to deliver updated BV estimates for glucose and HbA1c, including recently published high-quality studies such as the European Biological Variation study (EuBIVAS).MethodsSystematic literature searches were performed to identify BV studies. Nine publications not included in a previous review were identified; four for glycosylated albumin, three for glucose, and three for HbA1c. Relevant studies were appraised by the Biological Variation Data Critical Appraisal Checklist (BIVAC). Global BV estimates were derived by meta-analysis of BIVAC-compliant studies in healthy subjects with similar study design.ResultsOne study received BIVAC grade A, 2B, and 6C. In most cases, the C-grade was associated with deficiencies in statistical analysis. BV estimates for glycosylated albumin were: CVI=1.4% (1.2–2.1) and CVG=5.7% (4.7–10.6), whereas estimates for HbA1c, CVI=1.2% (0.3–2.5), CVG=5.4% (3.3–7.3), and glucose, CVI=5.0% (4.1–12.0), CVG=8.1% (2.7–10.8) did not differ from previously published global estimates.ConclusionsThe critical appraisal and rating of BV studies according to their methodological quality, followed by a meta-analysis, generate robust, and reliable BV estimates. This study delivers updated and evidence-based BV estimates for glycosylated albumin, glucose and HbA1c.

scholarly journals Serum NGAL, BNP, PTH, and albumin do not improve glomerular filtration rate estimating formulas in children

2021 ◽  
Author(s):  
Julie Mouron-Hryciuk ◽  
François Cachat ◽  
Paloma Parvex ◽  
Thomas Perneger ◽  
Hassib Chehade
Keyword(s):  
Glomerular Filtration Rate ◽  
Parathyroid Hormone ◽  
Serum Creatinine ◽  
Brain Natriuretic Peptide ◽  
Glomerular Filtration ◽  
Natriuretic Peptide ◽  
Cystatin C ◽  
Filtration Rate ◽  
Neutrophil Gelatinase Associated Lipocalin ◽  
Neutrophil Gelatinase

AbstractGlomerular filtration rate (GFR) is difficult to measure, and estimating formulas are notorious for lacking precision. This study aims to assess if the inclusion of additional biomarkers improves the performance of eGFR formulas. A hundred and sixteen children with renal diseases were enrolled. Data for age, weight, height, inulin clearance (iGFR), serum creatinine, cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), parathyroid hormone (PTH), albumin, and brain natriuretic peptide (BNP) were collected. These variables were added to the revised and combined (serum creatinine and cystatin C) Schwartz formulas, and the quadratic and combined quadratic formulas. We calculated the adjusted r-square (r2) in relation to iGFR and tested the improvement in variance explained by means of the likelihood ratio test. The combined Schwartz and the combined quadratic formulas yielded best results with an r2 of 0.676 and 0.730, respectively. The addition of BNP and PTH to the combined Schwartz and quadratic formulas improved the variance slightly. NGAL and albumin failed to improve the prediction of GFR further. These study results also confirm that the addition of cystatin C improves the performance of estimating GFR formulas, in particular the Schwartz formula.Conclusion: The addition of serum NGAL, BNP, PTH, and albumin to the combined Schwartz and quadratic formulas for estimating GFR did not improve GFR prediction in our population. What is Known:• Estimating glomerular filtration rate (GFR) formulas include serum creatinine and/or cystatin C but lack precision when compared to measured GFR.• The serum concentrations of some biological parameters such as neutrophil gelatinase-associated lipocalin (NGAL), parathyroid hormone (PTH), albumin, and brain natriuretic peptide (BNP) vary with the level of renal function. What is New:• The addition of BNP and PTH to the combined quadratic formula improved its performance only slightly. NGAL and albumin failed to improve the prediction of GFR further.

Ratio of serum creatinine to cystatin C is related to leg strength in predialysis CKD patients

2021 ◽  
Author(s):  
Kohei Shiomi ◽  
Chie Saito ◽  
Kei Nagai ◽  
Keisei Kosaki ◽  
Tetsuya Kawamura ◽  
...  
Keyword(s):  
Serum Creatinine ◽  
Cystatin C ◽  
Leg Strength
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