Evaluation of carbohydrate-deficient transferrin measurements on the V8 capillary electrophoresis system and comparison with the IFCC approved HPLC reference method and N-Latex immunonephelometric assay

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Leo H.J. Jacobs ◽  
Riekie M. te Stroet ◽  
Ayse Y. Demir
Keyword(s):  
High Performance ◽  
Clinical Chemistry ◽  
Method Comparison ◽  
Reference Method ◽  
Roc Curves ◽  
Serum Samples ◽  
Roc Curve Analysis ◽  
Chronic Alcohol Abuse ◽  
Carbohydrate Deficient Transferrin ◽  
Immunonephelometric Assay

AbstractObjectivesCarbohydrate-deficient transferrin (CDT) measurements are commonly used for the identification and follow-up of individuals suspected of chronic alcohol abuse. This study describes the analytical characteristics of the CDT assay on the Helena Biosciences V8 electrophoresis analyzer and compares its diagnostic performance to the International Federation of Clinical Chemistry and Laboratory Medicine approved high performance liquid chromatography (HPLC) method and the N-Latex CDT immunonephelometric assay.MethodsThe analytical performance of the V8 assay, including the linearity and the imprecision, was studied at two separate locations. Method comparison analysis was performed by studying the correlation, bias and agreement between the V8, HPLC and the N-Latex assays in 231 patient samples.ResultsThe total imprecision ranged between 5.1 and 24.3% and was ≤13.1% for samples with concentrations above the clinical cut-off value (≥1.62%). The method comparisons revealed excellent correlations with r2≥0.97 for all comparisons. Measurements on the V8 showed a bias of −0.83 (−22.24%) and −0.40 (−12.26%) with the HPLC and N-Latex assays, respectively. The assays showed excellent agreements (Kappa scores ≥ 0.8) in classifying subjects with elevated CDT values. Receiver operating characteristic (ROC)-curve analysis, using the HPLC classification as reference, revealed areas under the ROC-curves of 0.981 (95% CI, 0.97–0.99) and 0.996 (0.99–1.00) for the N-Latex and V8 assays, respectively.ConclusionsCDT measurements on the V8 assay are highly correlated with both the HPLC and the N-Latex assay and show excellent agreement in classifying subjects with elevated CDT values. Overall, the V8 CDT analysis is a robust, reliable and effective method to measure CDT concentrations in serum samples.

scholarly journals Development and Multicenter Evaluation of the N Latex CDT Direct Immunonephelometric Assay for Serum Carbohydrate-Deficient Transferrin

2007 ◽  
Vol 53 (6) ◽  
pp. 1115-1121 ◽  
Author(s):  
Joris R Delanghe ◽  
Anders Helander ◽  
Jos PM Wielders ◽  
J Maurits Pekelharing ◽  
Heinz J Roth ◽  
...  
Keyword(s):  
Alcohol Abuse ◽  
Genetic Variants ◽  
Reference Method ◽  
Sample Treatment ◽  
Serum Samples ◽  
Column Separation ◽  
Direct Immunoassay ◽  
Carbohydrate Deficient Transferrin ◽  
Healthy Control ◽  
Immunonephelometric Assay

Abstract Background: Carbohydrate-deficient transferrin (CDT) is a promising biomarker of alcohol abuse. We describe the development and multicenter evaluation of N Latex CDT (Dade Behring), an automated, particle-enhanced, homogeneous immunonephelometric assay for directly determining CDT. Methods: N Latex CDT uses a monoclonal antibody that recognizes the structure of transferrin glycoforms lacking 1 or 2 complete N-glycans [i.e., disialo-, monosialo-, and asialotransferrins (CDT glycoforms)] in combination with a simultaneous assay for total transferrin. The Dade Behring BN II™ and BN ProSpec® systems automatically calculate the CDT value as a percentage of total transferrin (%CDT). No preanalytical sample treatment is used. Results: Total imprecision values for serum pools containing 1.8%–8.7% CDT were 3.4%–10.4% (mean, 6.8%). The mean (SD) %CDT for 561 serum samples from healthy control individuals was 1.76% (0.27%; range, 1.01%–2.85%). No marked sex or age differences were noted. The 97.5th percentile was at 2.35%. Transferrin genetic variants did not interfere with measurements. High transferrin concentrations did not falsely increase %CDT values, but increased %CDT values were noted for some samples with transferrin concentrations <1.1 g/L. N Latex CDT results correlated with those of a commercial CDT immunoassay involving column separation (r2 = 0.862) and an HPLC candidate reference method (r2 = 0.978). Conclusion: N Latex CDT is the first direct immunoassay for quantifying %CDT in serum. The specificity of N Latex CDT for identifying alcohol abuse may be higher than for immunoassays that use column separation, because transferrin genetic variants do not interfere with measurements.

Diagnostic performance of distinct metabolic features in the plasma of patients with silicosis

2020 ◽  
Author(s):  
Changjiang Xue ◽  
Na Wu ◽  
Yali Fan ◽  
Jing Ma ◽  
Qiao Ye
Keyword(s):  
Pilot Study ◽  
Validation Study ◽  
High Performance ◽  
Interstitial Fibrosis ◽  
Roc Curves ◽  
Sphingolipid Metabolism ◽  
Control Group ◽  
Plasma Samples ◽  
Proline Metabolism ◽  
Roc Curve Analysis

Abstract Background Silicosis is a progressive pneumoconiosis characterized by interstitial fibrosis following exposure to silica dust. This study aimed to identify potential noninvasive metabolic biomarkers for the diagnosis and monitoring of this condition by pilot and validation analyses of patients with silicosis in metabolomics studies.Methods Patients with silicosis, dust-exposed workers (DEWs) without silicosis and age-matched healthy controls were recruited in a case-control study. Plasma samples were collected, and metabolomics analyses by ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) were conducted. Distinct metabolic features (DMFs) among the groups were identified in the pilot study and were validated in the validation study. The enriched signalling pathways of these DMFs were determined. The ability of DMFs to discriminate among the groups in the validation study was analysed through receiver operating characteristic (ROC) curves. The correlations between DMFs and clinical features were also explored.Results Twenty-nine DMFs and 9 DMFs were detected in the plasma of the DEW and silicosis groups, respectively, compared with the control group; these features showed the same trend in the pilot study and the validation study. Sphingolipid metabolism was the major metabolic pathway in the DEWs, and arginine and proline metabolism was associated with silicosis. Twenty DMFs in the DEWs and 3 DMFs in the patients with silicosis showed a discriminatory ability with ROC curve analysis. The abundance of kynurenine was higher in Stage III silicosis than in Stage I or Stage II silicosis. L-arginine and kynurenine were both negatively correlated with the percentage of forced vital capacity predicted in silicosis.Conclusions Distinct metabolic features of plasma samples related to sphingolipid metabolism and arginine and proline metabolism were identified in the DEW and silicosis groups, respectively. L-arginine and kynurenine may have a predictive role in the diagnosis and severity of silicosis.

scholarly journals IFCC Reference System for Measurement of Hemoglobin A1c in Human Blood and the National Standardization Schemes in the United States, Japan, and Sweden: A Method-Comparison Study

2004 ◽  
Vol 50 (1) ◽  
pp. 166-174 ◽  
Author(s):  
Wieland Hoelzel ◽  
Cas Weykamp ◽  
Jan-Olof Jeppsson ◽  
Kor Miedema ◽  
John R Barr ◽  
...  
Keyword(s):  
Reference System ◽  
Clinical Chemistry ◽  
Method Comparison ◽  
Reference Method ◽  
The United States ◽  
Reference Laboratory ◽  
Regression Equations ◽  
National Programs ◽  
Method Comparison Study ◽  
The Relationship

Abstract Background: The national programs for the harmonization of hemoglobin (Hb)A1c measurements in the US [National Glycohemoglobin Standardization Program (NGSP)], Japan [Japanese Diabetes Society (JDS)/Japanese Society of Clinical Chemistry (JSCC)], and Sweden are based on different designated comparison methods (DCMs). The future basis for international standardization will be the reference system developed by the IFCC Working Group on HbA1c Standardization. The aim of the present study was to determine the relationships between the IFCC Reference Method (RM) and the DCMs. Methods: Four method-comparison studies were performed in 2001–2003. In each study five to eight pooled blood samples were measured by 11 reference laboratories of the IFCC Network of Reference Laboratories, 9 Secondary Reference Laboratories of the NGSP, 3 reference laboratories of the JDS/JSCC program, and a Swedish reference laboratory. Regression equations were determined for the relationship between the IFCC RM and each of the DCMs. Results: Significant differences were observed between the HbA1c results of the IFCC RM and those of the DCMs. Significant differences were also demonstrated between the three DCMs. However, in all cases the relationship of the DCMs with the RM were linear. There were no statistically significant differences between the regression equations calculated for each of the four studies; therefore, the results could be combined. The relationship is described by the following regression equations: NGSP-HbA1c = 0.915(IFCC-HbA1c) + 2.15% (r2 = 0.998); JDS/JSCC-HbA1c = 0.927(IFCC-HbA1c) + 1.73% (r2 = 0.997); Swedish-HbA1c = 0.989(IFCC-HbA1c) + 0.88% (r2 = 0.996). Conclusion: There is a firm and reproducible link between the IFCC RM and DCM HbA1c values.

Comparison of the International Federation of Clinical Chemistry and Japan Diabetes Society reference methods for conversion to the National Glycohemoglobin Standardization Program values

2019 ◽  
Vol 56 (4) ◽  
pp. 508-514
Author(s):  
Katsuyuki Nakajima ◽  
Isao Koyama ◽  
Makoto Watanabe ◽  
Masakazu Nakamura ◽  
Yoshihiro Miyamoto ◽  
...  
Keyword(s):  
Clinical Chemistry ◽  
Method Comparison ◽  
Reference Method ◽  
International Federation ◽  
Haemoglobin A1c ◽  
Regression Equations ◽  
National Programmes ◽  
The Us ◽  
Level 1 ◽  
The Relationship

Background The national programmes for the harmonization of haemoglobin A1c measurement in the US and Japan are based on differently designated comparison methods. The future basis for international standardization is expected to be the reference system developed by the International Federation of Clinical Chemistry (IFCC) Working Group on haemoglobin A1c Standardization. The aim of the present study is to compare the relationship between the IFCC reference method (RM) and Japanese Diabetes Society (JDS) RM used for the conversion to the National Glycohemoglobin Standardization Program (NGSP) values. Methods Three different method-comparison studies were performed. All blood samples were measured at the National Cerebral and Cardiovascular Centers (Lipid Reference Laboratories) that serve as Level 1 reference laboratories of the NGSP Network. Regression equations were calculated for the IFCC RM and JDS RM for the conversion to NGSP values. Results Differences were found between the haemoglobin A1c values of the IFCC RM and those of JDS. However, in all cases, the relationships of the IFCC RM and JDS RM were linear and commutable. The relationship is described by the following regression equations: NGSP-HbA1c = 0.915(IFCC-HbA1c) + 2.15% (r2 = 0.998); JDS/JSCC-HbA1c = 0.927(IFCC-HbA1c) + 1.73% (r2 = 0.997). Conclusion There is a firm and reproducible link between the IFCC and JDS-HbA1c values. However, the values calibrated by JDS RM were consistently and significantly higher than the IFCC values (0.1–0.2%) when used for conversion to the NGSP values.

scholarly journals Measurements for 8 Common Analytes in Native Sera Identify Inadequate Standardization among 6 Routine Laboratory Assays

2014 ◽  
Vol 60 (6) ◽  
pp. 855-863 ◽  
Author(s):  
Hedwig C M Stepman ◽  
Ulla Tiikkainen ◽  
Dietmar Stöckl ◽  
Hubert W Vesper ◽  
Selvin H Edwards ◽  
...  
Keyword(s):  
Uric Acid ◽  
Ldl Cholesterol ◽  
Peer Group ◽  
Clinical Chemistry ◽  
Total Error ◽  
Random Access ◽  
Reference Method ◽  
Hdl Cholesterol ◽  
Serum Samples ◽  
Fresh Frozen

Abstract BACKGROUND External quality assessment (EQA) with commutable samples is essential for assessing the quality of assays performed by laboratories, particularly when the emphasis is on their standardization status and interchangeability of results. METHODS We used a panel of 20 fresh-frozen single-donation serum samples to assess assays for the measurement of creatinine, glucose, phosphate, uric acid, total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides. The commercial random access platforms included: Abbott Architect, Beckman Coulter AU, Ortho Vitros, Roche Cobas, Siemens Advia, and Thermo Scientific Konelab. The assessment was done at the peer group level and by comparison against the all-method trimmed mean or reference method values, where available. The considered quality indicators were intraassay imprecision, combined imprecision (including sample–matrix interference), bias, and total error. Fail/pass decisions were based on limits reflecting state-of-the-art performance, but also limits related to biological variation. RESULTS Most assays showed excellent peer performance attributes, except for HDL- and LDL cholesterol. Cases in which individual assays had biases exceeding the used limits were the Siemens Advia creatinine (−4.2%), Ortho Vitros phosphate (8.9%), Beckman Coulter AU triglycerides (5.4%), and Thermo Scientific Konelab uric acid (6.4%), which lead to considerable interassay discrepancies. Additionally, large laboratory effects were observed that caused interlaboratory differences of >30%. CONCLUSIONS The design of the EQA study was well suited for monitoring different quality attributes of assays performed in daily laboratory practice. There is a need for improvement, even for simple clinical chemistry analytes. In particular, the interchangeability of results remains jeopardized both by assay standardization issues and individual laboratory effects.

Pattern of partitioning of aflatoxins from feed to urine and its effect on serum chemistry in Nili-Ravi buffalo heifers

2014 ◽  
Vol 54 (10) ◽  
pp. 1671
Author(s):  
N. Aslam ◽  
Z. M. Iqbal ◽  
H. M. Warriach ◽  
P. C. Wynn
Keyword(s):  
Total Protein ◽  
High Performance ◽  
Clinical Chemistry ◽  
Serum Glucose ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Serum Samples ◽  
Significant Difference ◽  
High Concentrations ◽  
Group D

The objectives of the present study were (1) to monitor the pattern of excretion of aflatoxinM1 in urine after its conversion from aflatoxinB1 and (2) to observe the effects of different levels of aflatoxinB1 in feed on serum concentrations of key metabolites glucose, total protein, cholesterol and urea as indicators of metabolic status. Nili-Ravi buffalo heifers (n = 12) of similar age and weight were randomly distributed to four groups. Animals in Groups A, B and C were offered a contaminated cottonseed cake-based concentrate ration at 0.5%, 1.0% and 1.5% of bodyweight, respectively. Control animals in Group D were fed with aflatoxinB1-free green fodder. Based on the level of contamination of the concentrate ration with aflatoxinB1 (554 µg/kg), Groups A, B and C consumed 953, 2022, 3202 µg of aflatoxinB1 daily. Feed samples were analysed at Romer Laboratories Pty Ltd, Singapore by high performance liquid chromatography. AflatoxinM1 quantification in urine samples was conducted using a competitive enzyme-linked immunosorbent assay with kits supplied by Helica Biosystems, Inc., USA. Serum samples were analysed for concentrations of glucose, total protein, cholesterol and urea using clinical chemistry kits provided by Human diagnostics (HUMAN, Biochemica und Diagnostica mbH, Germany). Carry-over rate of aflatoxinM1 in urine for Groups A, B and C was 15.51%, 15.44% and 14.04% of aflatoxinB1 while there was no detectable aflatoxinM1 in the urine of the control group (D). There was no significant difference in the concentrations of serum glucose, total protein and cholesterol between treatment groups. However, the concentration of serum urea was significantly higher (P < 0.05) in the group offered the highest level of aflatoxinB1-contaminated concentrate. This result suggests that mycotoxicosis may compromise protein metabolism and accretion in affected animals. This leaves open the possibility that high concentrations of aflatoxins in milk may ultimately affect the health status of human milk consumers.

Toward standardization of carbohydrate-deficient transferrin (CDT) measurements: I. Analyte definition and proposal of a candidate reference method

2007 ◽  
Vol 45 (4) ◽  
Author(s):  
International Federation of Clinica Jeppsson ◽  
Torsten Arndt ◽  
François Schellenberg ◽  
Jos P.M. Wielders ◽  
Raymond F. Anton ◽  
...  
Keyword(s):  
Clinical Chemistry ◽  
Reference Method ◽  
Laboratory Medicine ◽  
International Federation ◽  
Serum Transferrin ◽  
Clinical Use ◽  
Primary Target ◽  
Heavy Alcohol Consumption ◽  
Carbohydrate Deficient Transferrin ◽  
A Current

AbstractAn alcohol-associated change in the serum transferrin glycoform pattern, carbohydrate-deficient transferrin (CDT), is used as a biomarker of chronic moderate to heavy alcohol consumption. A current limitation in CDT analysis is the lack of standardization, which hampers clinical and analytical comparison between studies. This situation prompted initiation of a Working Group (WG) on CDT Standardization under the auspices of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). The standardization work aims to define and validate the analyte, select a reference method, work out procedures for the production of reference materials, and make suggestions for the clinical usage of CDT. The first recommendation of the WG is that disialotransferrin should be the primary target molecule for CDT measurement and the single analyte on which CDT standardization is based. It is further recommended that HPLC should be the analytical principle considered as the basis of an interim reference method until a suitable mass spectrometric reference method is established. In clinical use, CDT should be expressed in a relative amount (% CDT), to compensate for variations in the total transferrin concentration.Clin Chem Lab Med 2007;45:558–62.

scholarly journals The Ratio of Trypsin-2-α1-Antitrypsin to Trypsinogen-1 Discriminates Biliary and Alcohol-induced Acute Pancreatitis

2001 ◽  
Vol 47 (2) ◽  
pp. 231-236 ◽  
Author(s):  
Jan M Andersén ◽  
Johan Hedström ◽  
Esko Kemppainen ◽  
Patrik Finne ◽  
Pauli Puolakkainen ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
Rapid Determination ◽  
Roc Curves ◽  
Curve Analysis ◽  
Central Hospital ◽  
Serum Samples ◽  
Roc Curve Analysis ◽  
Time Resolved ◽  
Appropriate Treatment

Abstract Background: Rapid determination of the etiology of acute pancreatitis (AP) enables institution of appropriate treatment. We evaluated the ability of trypsinogen-1, trypsinogen-2, trypsin-1-α1-antitrypsin (AAT), and trypsin-2-AAT in serum to identify the etiology of AP. Methods: The study consisted of 67 consecutive patients with AP admitted to Helsinki University Central Hospital. Forty-two had alcohol-induced AP, 16 had biliary AP, and 9 had unexplained etiology. Serum samples were drawn within 12 h after admission. Trypsinogen-1, trypsinogen-2, trypsin-1-AAT, and trypsin-2-AAT were determined by time-resolved immunofluorometric assays. Logistic regression was used to estimate the ability of the serum analytes to discriminate between alcohol-induced and biliary AP. The validity of the tests was evaluated by ROC curve analysis. Results: Patients with alcohol-induced AP had higher median values of trypsin-1-AAT (P = 0.065), trypsinogen-2 (P = 0.034), and trypsin-2-AAT (P &lt;0.001) than those with biliary AP, who had higher values of amylase (P = 0.002), lipase (P = 0.012), and alanine aminotransferase (P = 0.036). The ratios of trypsin-2-AAT to trypsinogen-1, lipase, or amylase efficiently discriminated between biliary and alcohol-induced AP (areas under ROC curves, 0.92–0.96). Conclusions: Trypsinogen-2 and trypsin-2-AAT are markedly increased in AP of all etiologies, whereas trypsinogen-1 is increased preferentially in biliary AP. The trypsin-2-AAT/trypsinogen-1 ratio is a promising new marker for discrimination between biliary and alcohol-induced AP.

scholarly journals A proof-of-concept analysis of carbohydrate-deficient transferrin by imaged capillary isoelectric focusing and in-capillary immunodetection

BioTechniques ◽  
2020 ◽  
Vol 68 (2) ◽  
pp. 85-90 ◽  
Author(s):  
Jiaqi Wu ◽  
Charles H Haitjema ◽  
Christopher D Heger ◽  
Annegret Boge
Keyword(s):  
Alcohol Abuse ◽  
Isoelectric Focusing ◽  
Capillary Isoelectric Focusing ◽  
Chronic Alcohol ◽  
Proof Of Concept ◽  
Serum Samples ◽  
Chronic Alcohol Abuse ◽  
Isoelectric Points ◽  
Carbohydrate Deficient Transferrin ◽  
Expected Values

Carbohydrate-deficient transferrin (CDT) is a reliable biomarker for chronic alcohol abuse. We developed a method for CDT analysis by capillary isoelectric focusing, followed by immunodetection directly in the capillary, in an automated fashion and on a single platform (Peggy Sue™; ProteinSimple, CA, USA). Transferrin glycoforms in serum samples, including disialo-transferrin, were separated and their apparent isoelectric points and relative percentages were determined. The relative CDT values (percent of total transferrin) matched expected values for both healthy and alcoholic samples. Because the method leveraged the sensitivity of an immunoassay, CDT was measured when serum samples were diluted up to 1200-fold, reducing the volume of serum required. Finally, the process is fully automated, with up to 96 samples analyzed per batch.

Glycated Hemoglobin Measurement: Comparison of Three Methods Versus High Performance Liquid Chromatography

2021 ◽  
pp. 193229682199717
Author(s):  
María Zulema Chaila ◽  
Matías Viniegra ◽  
Juan José Gagliardino ◽  
Alfredo Martínez ◽  
María Gabriela Simesen de Bielke ◽  
...  
Keyword(s):  
High Performance ◽  
Glycated Hemoglobin ◽  
Clinical Chemistry ◽  
Intraclass Correlation ◽  
Method Comparison ◽  
Control Program ◽  
International Federation ◽  
High Complexity ◽  
Quality Control Program ◽  
Mean Values

Background: HbA1c result provide information on metabolic control in diabetes mellitus (DM) and could also be used for its diagnosis. For its determination, the laboratory must be certified by the National Glycohemoglobin Standardization Program (NGSP) or the International Federation of Clinical Chemistry (IFCC) and comply with a strict quality control program. Aims: To determine the correlation and agreement between HbA1c results measured by three analytical methods (enzymatic, turbidimetric, and capillary electrophoresis) versus HPLC. Methods: Method comparison—1245 samples from equal number of subjects at 45 Association of High Complexity Laboratories (Asociación de Laboratorios de Alta Complejidad—ALAC) centers, centralizing sample processing and operator. Statistical analysis—analysis of variance (ANOVA) and nonparametric Friedman ANOVA test for related samples, means, and medians. Correlation and concordance—Pearson’s correlation and linear regression, intraclass correlation coefficient (Passing and Bablock and Bland and Altman). Results: The comparison of mean values obtained by the four methods showed statistically significant, but clinically irrelevant, differences: HbA1c by HPLC versus Electrophoresis 0.06% (0.42 mmol/mol) P = .000 (± 1.96 DS -0.070 -0.047), Enzymatic 0.087% (1 mmol/mol) P = .000 (± 1.96 DS 0.077 0.098), Turbidimetric 0.056% (0.38 mmol/mol) P = 0.000 (± 1.96 DS -0.067 -0.044). Their concordance showed intraclass correlation of single measures of 0.982 P < .001 (95% CI 0.987 - 0.9838). Conclusions: The three methods present low variability and high correlation versus the HPLC.

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