Multicentre evaluation of the Tosoh HbA1c G8 analyser

Background: We report a Dutch-Belgian multicentre evaluation of the Tosoh HLC-723G8 glycohaemoglobin analyser, an ion-exchange HPLC instrument for the separation and quantification of haemoglobin A1c (HbA1c) in whole blood. Methods: We evaluated the analytical performances of the Tosoh G8 analyser and compared the results for blood samples with its predecessor, the Tosoh G7, and with two other widely used analysers, the Bio-Rad Variant II and Adams Arkray HA-8160. Results: Within-and between-batch imprecision [coefficient of variation (CVs)] was <0.5% and 2%, respectively, and compared favourably with the G7. The excellent performances in terms of speed (1.6 min/analysis) did not result in increased variability of the results or carry-over between samples. The method shows no interference from carbamylated haemoglobin, and recognises the presence of haemoglobinopathies, which triggers the correction of the HbA1c result. Comparison with established methods showed good correlation, not only with the G7 but also with the Variant II and HA-8160 systems. Conclusions: With respect to reproducibility, chromatographic resolution, speed of analysis and identification of Hb variants, the Tosoh G8 analyser can be considered to be state of the art. Clin Chem Lab Med 2010;48:365-71

The EuBIVAS project:within- and between-subject biological variation data for serum creatinine using enzymatic and alkaline picrate methods and implications for monitoring

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. </jats:sec

Sample collections from healthy volunteers for biological variation estimates' update:A new project undertaken by the Working Group on Biological Variation established by the European Federation of Clinical Chemistry and Laboratory Medicine

Background: Biological variation (BV) data have many fundamental applications in laboratory medicine. At the 1st Strategic Conference of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) the reliability and limitations of current BV data were discussed. The EFLM Working Group on Biological Variation is working to increase the quality of BV data by developing a European project to establish a biobank of samples from healthy subjects to be used to produce high quality BV data. Methods: The project involved six European laboratories (Milan, Italy; Bergen, Norway; Madrid, Spain; Padua, Italy; Istanbul, Turkey; Assen, The Netherlands). Blood samples were collected from 97 volunteers (44 men, aged 20-60 years; 43 women, aged 20-50 years; 10 women, aged 55-69 years). Initial subject inclusion required that participants completed an enrolment questionnaire to verify their health status. The volunteers provided blood specimens once per week for 10 weeks. A short questionnaire was completed and some laboratory tests were performed at each sampling consisting of blood collected under controlled conditions to provide serum, K(2)EDTA-plasma and citrated-plasma samples. Results: Samples from six out of the 97 enroled subjects were discarded as a consequence of abnormal laboratory measurements. A biobank of 18,000 aliquots was established consisting of 120 aliquots of serum, 40 of EDTA-plasma, and 40 of citrated-plasma from each subject. The samples were stored at -80 degrees C. Conclusions: A biobank of well-characterised samples collected under controlled conditions has been established delivering a European resource to enable production of contemporary BV data

The EuBIVAS:Within- and between-subject biological variation data for electrolytes, lipids, urea, uric acid, total protein, total bilirubin, direct bilirubin, and glucose

BACKGROUND: The European Federation of Clinical Chemistry and Laboratory Medicine European Biological Variation Study (EuBIVAS) has been established to deliver rigorously determined data describing biological variation (BV) of clinically important measurands. Here, EuBIVAS-based BV estimates of serum electrolytes, lipids, urea, uric acid, total protein, total bilirubin, direct bilirubin, and glucose, as well as their associated analytical performance specifications (APSs), are presented. METHOD: Samples were drawn from 91 healthy individuals (38 male, 53 femaleage range, 21-69 years) for 10 consecutive weeks at 6 European laboratories. Samples were stored at -80 degrees C before duplicate analysis of all samples on an ADVIA 2400 (Siemens Healthineers). Outlier and homogeneity analyses were performed, followed by CV-ANOVA on trend-corrected data, when relevant, to determine BV estimates with CIs. RESULTS: The within-subject BV (CVI) estimates of all measurands, except for urea and LDL cholesterol, were lower than estimates available in an online BV database, with differences being most pronounced for HDL cholesterol, glucose, and direct bilirubin. Significant differences in CVI for men and women/women <50 years of age were evident for uric acid, triglycerides, and urea. The CVA obtained for sodium and magnesium exceeded the EuBIVAS-based APS for imprecision. CONCLUSIONS: The EuBIVAS, which is fully compliant with the recently published Biological Variation Data Critical Appraisal Checklist, has produced well-characterized, high-quality BV estimates utilizing a stringent experimental protocol. These new reference data deliver revised and more exacting APS and reference change values for commonly used clinically important measurands, thus having direct relevance to diagnostics manufacturers, service providers, clinical users, and ultimately patients. (c) 2018 American Association for Clinical Chemistry.9SEP1380-13936