Centralization of multisite reagent lot-to-lot validation for Ortho Clinical Vitros chemistry instruments.

OBJECTIVE: Reagent lot-to-lot comparisons are recommended by accreditation bodies to ensure that the performance of each reagent lot meets acceptable standards for quality patient results. The general approach is comprised of performing quality control (QC) and patient comparison between the old and new reagent lots and evaluating against a pre-defined criteria. Reagent lot comparison practices are often variable despite using the same instrument across different laboratories. This is costly, time consuming, and can lead to variability in acceptance criteria. While Clinical & Laboratory Standards Institute (CLSI) has a recommended guideline for reagent lot validation, it is often difficult to execute for small and rural laboratories due to limited resources. Defining the analytes required for detailed validation is important to allocate appropriate resources to ensure quality patient results. The goal of this study was to develop a standardized approach to reagent lot validation and optimize lab resources on Vitros chemistry instruments. DESIGN AND METHOD: This study consists of a retrospective and prospective analysis of reagent lot changes in dry slide chemistry analyzers (Ortho Clinical Diagnostics Vitros). Two years of retrospective reagent lot comparison data was obtained at a single site. A prospective study was conducted by assessing aliquots of 10 patient sample pools at 9 sites with Vitros analyzers. RESULTS: Of the 19 chemistry analytes evaluated, albumin, sodium, and total protein showed significant differences between reagent lots and also exceeded the pre-defined acceptance criteria. CONCLUSION: For these analytes, our recommendations are to perform a comprehensive lot validation with QC and patient samples. A simple lot validation with a reflex approach comprised of initially assaying QC can be adapted for the more stable analytes to allow achieving quality patient result in a resource constraint rural environment.

Impact of managing affected results in haemolysed samples of an infant-maternity hospital using an unconventional approach.

BACKGROUND: The management of affected results in haemolysed samples (HS) is debated. In an infant-maternity setting, for reporting interfered test results, we provided the result itself, the degree of haemolysis (as free haemoglobin concentration), and a warning recommending sample recollection. We investigated the impact of this approach on sample quality and clinicians' decision-making. METHODS: Free haemoglobin was measured on Beckman Coulter AU680 as haemolytic index. We estimated the total HS number, the clinical wards more affected by HS, the most interfered analytes, and the retesting rate of interfered tests, by comparing data from Apr-Dec 2017, the period just after the introduction of the new policy, vs. Apr-Dec 2018. RESULTS: One year after the new report introduction, a significant HS decrease (5.8% vs. 7.8%, P < 0.001) was detected, together with a reduction of the frequency by which haemolysis affected results. The most affected wards, i.e., Paediatric and Neonatal Intensive Care Units, showed an improvement in sample quality (HS rate, 30.6% to 16.1%, P < 0.001, and 25.2% to 20.9%, P = 0.048, respectively). We noted a significant decrease in retesting after an alerted result for aspartate aminotransferase, magnesium, potassium, conjugated bilirubin, and lactate dehydrogenase. CONCLUSIONS: Our approach led to a HS decrease, suggesting that the provided report could be a driving force for improvement of phlebotomy quality, also helping clinicians in deciding if retesting is essential or not.

Comparison of regression for blood ALP levels using methods of the Japan Society of Clinical Chemistry and the International Federation of Clinical Chemistry and Laboratory Medicine in bovine, canine, feline, and human testing.

Livestock and companion animal health have a direct impact on human health. Research on clinical laboratory technology for veterinary medicine is as important as that on human laboratory technology. Reagents and analysis equipment for human medical laboratory tests are often used in veterinary medicine. Medical laboratories in Japan utilize the Japan Society of Clinical Chemistry (JSCC) method for blood alkaline phosphatase (ALP) analysis. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) method is used worldwide for ALP catalytic concentration measurement. When the IFCC method is used, human blood ALP activity is approximately one-third of the JSCC method's activity. The JSCC method for ALP measurement was switched to the IFCC method in medical laboratories in Japan in April 2020 for global standardization purpose. It is uncertain whether conventional JSCC method reagents will continue to be supplied. In veterinary medicine, the relationship between the JSCC and IFCC methods in terms of ALP measurement is almost unclear. This study investigated the regression between JSCC and IFCC methods measuring ALP in bovine, canine, feline, and human. The regression formulas for bovine, canine, feline, and human ALP values using the conventional JSCC (x) and IFCC (y) methods are y = 0.379x + 0.124, y = 0.289x + 8.291, y = 0.358x + 0.432, and y = 0.337x + 2.959, respectively. These results suggested that the IFCC method measurement could be estimated by approximately one-third of the JSCC method measurement in animal species such as bovine, canine, and feline. By applying the conversion factors proposed in this study, a very good correlation could be obtained between the two methods for each animal.

Turnaround times and modes of reporting critical results in Asian laboratories.

BACKGROUND: Reporting critical results in a timely manner is a crucial role of clinical laboratories. Traditionally, these results were reported using the phone or fax system. However, there are now other modes of communication for this reporting. Quality improvement in any organization is driven by detection of errors and benchmarking against peers. In the case of critical result reporting, there are few current widely used Benchmarking schemes. METHODS: The Roche Clinical Chemistry Benchmarking Survey in 2019 added questions about critical result reporting including the mode of communication and turnaround time key performance index. This survey includes over 1100 laboratories from 20 countries. RESULTS: The survey revealed a range of communication strategies with phone calls still the commonest followed by email. The key performance index for most laboratories was less than 10 min. CONCLUSION: Benchmarking can provide key information for quality improvement activities, particularly pre- and postanalytical.

[Analysis of Class II Common Problems in the Registration of in Vitro Diagnostic Reagent (Kit) for Clinical Chemistry].

From the perspective of technical review, this paper made statistics on the supplement contents of in vitro diagnostic reagent (kit) for clinical chemistry registered in Zhejiang province in the past five years, summarized and analyzed the common problems, and put forward corresponding suggestions based on the common problems encountered in the public welfare training of registered specialists in Zhejiang province. The aim is to provide technical reference for registrars to prepare registration documents reasonably and efficiently and for review staffs to strengthen their points of focus.

Sample size and rejection limits for detecting reagent lot variability: analysis of the applicability of the Clinical and Laboratory Standards Institute (CLSI) EP26-A protocol to real-world clinical chemistry data.

Objectives: To maintain the consistency of laboratory test results, between-reagent lot variation should be verified before using new reagent lots in clinical laboratory. Although the Clinical and Laboratory Standards Institute (CLSI) document EP26-A deals with this issue, evaluation of reagent lot-to-lot difference is challenging in reality. We aim to investigate a practical way for determining between-reagent lot variation using real-world data in clinical chemistry. Methods: The CLSI EP26-A protocol was applied to 83 chemistry tests in three clinical labs. Three criteria were used to define the critical difference (CD) of each test as follows: reference change value and total allowable error, which are based on biological variation, and acceptable limits by external quality assurance agencies. The sample size and rejection limits that could detect CD between-reagent lots were determined. Results: For more than half of chemistry tests, reagent lot-to-lot differences could be evaluated using only one patient sample per decision level. In many cases, the rejection limit that could detect reagent lot-to-lot difference with ≥90% probability was 0.6 times CD. However, the sample size and rejection limits vary depending on how the CD is defined. In some cases, impractical sample size or rejection limits were obtained. In some cases, information on sample size and rejection limit that met intended statistical power was not found in EP26-A. Conclusions: The CLSI EP26-A did not provide all necessary answers. Alternative practical approaches are suggested when CLSI EP26-A does not provide guidance.

The CRESS checklist for reporting stability studies: on behalf of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for the Preanalytical Phase (WG-PRE).

To ensure that clinical laboratories produce results that are both accurate and of clinical utility it is essential that only samples of adequate quality are analysed. Although various studies and databases assessing the stability of analytes in different settings do exist, guidance on how to perform and report stability studies is lacking. This results in studies that often do not report essential information, thus compromising transferability of the data. The aim of this manuscript is to describe the Checklist for Reporting Stability Studies (CRESS) against which future studies should be reported to ensure standardisation of reporting and easy assessment of transferability of studies to other healthcare settings. The EFLM WG-PRE (European Federation of Clinical Chemistry and Laboratory Medicine Working Group for the Preanalytical Phase) produced the CRESS checklist following a detailed literature review and extensive discussions resulting in consensus agreement. The checklist consists of 20 items covering all the aspects that should be considered when producing a report on a stability study including details of what should be included for each item and a rationale as to why. Adherence to the CRESS checklist will ensure that studies are reported in a transparent and replicable way. This will allow other laboratories to assess whether published data meet the stability criteria required in their own particular healthcare scenario. The EFLM WG-PRE encourage researchers and authors to use the CRESS checklist as a guide to planning stability studies and to produce standardised reporting of future stability studies.

Long-term stability of clinically relevant chemistry analytes in pleural and peritoneal fluid.

INTRODUCTION: Our aim was to investigate the stability of clinically relevant analytes in pleural and peritoneal fluids stored in variable time periods and variable storage temperatures prior to analysis. MATERIALS AND METHODS: Baseline total proteins (TP), albumin (ALB), lactate dehydrogenase (LD), cholesterol (CHOL), triglycerides (TRIG), creatinine (CREA), urea, glucose and amylase (AMY) were measured using standard methods in residual samples from 29 pleural and 12 peritoneal fluids referred to our laboratory. Aliquots were stored for 6 hours at room temperature (RT); 3, 7, 14 and 30 days at - 20°C. At the end of each storage period, all analytes were re-measured. Deviations were calculated and compared to stability limits (SL). RESULTS: Pleural fluid TP and CHOL did not differ in the observed storage periods (P = 0.265 and P = 0.170, respectively). Statistically significant differences were found for ALB, LD, TRIG, CREA, urea, glucose and AMY. Peritoneal fluid TP, ALB, TRIG, urea and AMY were not statistically different after storage, contrary to LD, CHOL, CREA and glucose. Deviations for TP, ALB, CHOL, TRIG, CREA, urea and AMY in all storage periods tested for both serous fluids were within the SL. Deviations exceeding SL were observed for LD and glucose when stored for 3 and 7 days at - 20°C, respectively. CONCLUSIONS: TP, ALB, CHOL, TRIG, CREA, urea and AMY are stable in serous samples stored up to 6 hours at RT and/or 30 days at - 20°C. Glucose is stable up to 6 hours at RT and 3 days at - 20°C. The stability of LD in is limited to 6 hours at RT.

Community based reference interval of selected clinical chemistry parameters among apparently healthy Adolescents in Mekelle City, Tigrai, Northern Ethiopia.

BACKGROUND: Locally established clinical laboratory reference intervals (RIs) are required to interpret laboratory test results for screening, diagnosis and prognosis. The objective of this study was establishing reference interval of clinical chemistry parameters among apparently healthy adolescents aged between 12 and 17 years in Mekelle, Tigrai, northern part of Ethiopia. METHODS: Community based cross sectional study was employed from December 2018 to March 2019 in Mekelle city among 172 males and 172 females based on Multi stage sampling technique. Blood samples were tested for Fasting blood sugar (FBS), alanine aminino transferase (ALT), aspartate amino transferase (AST), alkaline phosphatase (ALP), Creatinine, urea, total protein, albumin (ALB), direct and indirect bilirubin (BIL.D and BIL.T) using 25 Bio system clinical chemistry analyzer. Results were analyzed using SPSS version 23 software and based on the Clinical Laboratory Standard Institute (CLSI)/ International Federation of Clinical Chemistry (IFCC) C 28-A3 Guideline which defines the reference interval as the 95% central range of 2.5th and 97.5th percentiles. Mann Whitney U test, descriptive statistics and box and whisker were statistical tools used for analysis. RESULTS: This study observed statistically significant differences between males and females in ALP, ALT, AST, Urea and Creatinine Reference intervals. The established reference intervals for males and females, respectively, were: ALP (U/L) 79.48-492.12 versus 63.56-253.34, ALT (U/L) 4.54-23.69 versus 5.1-20.03, AST 15.7-39.1 versus 13.3-28.5, Urea (mg/dL) 9.33-24.99 versus 7.43-23.11, and Creatinine (mg/dL) 0.393-0.957 versus 0.301-0.846. The combined RIs for Total Protein (g/dL) was 6.08-7.85, ALB (g/dL) 4.42-5.46, FBS(mg/dL) 65-110, BIL.D (mg/dL) 0.033-0.532, and BIL.T (mg/dL) 0.106-0.812. CONCLUSIONS: The result showed marked difference among sex and with the company derived values for selected clinical chemistry parameters. Thus, use of age and sex specific locally established reference intervals for clinical chemistry parameters is recommended.

Human apolipoprotein CIII levels; evaluation of three assay methods.

Apolipoprotein CIII (apoCIII) is associated with triglyceride (TG)-rich particles like VLDL and exerts an inhibitory effect of lipoprotein lipase. Increased levels are related to cardiovascular diseases and diabetes and therefore apoCIII has been proposed as a useful biomarker. Even if several commercial assays for measuring apoCIII in human plasma/serum are available, data is scarce concerning their reliability and none is used clinically. In the present study a comparative investigation has been done. Two ELISA-based methods (Cusabio Biotech and Assay Pro) and one nephelometric assay (Siemens Healthcare) were investigated. Serum and plasma samples were obtained from healthy volunteers and from samples sent to the Laboratory of Clinical Chemistry, preferably with higher levels of TGs. The Cusabio Biotech assay did not yield any valid results. However, both the methods from Assay Pro and Siemens Healthcare showed good performance with similar dynamic ranges. The latter assay had lower CV and required less work. In healthy individuals, apoCIII levels were not affected by fasting, freezing or thawing, nor did we find any gender differences. Individuals with elevated levels of TG displayed higher apoCIII values. Females with oral intake of contraceptives had higher levels. In conclusion, the nephelometric assay showed the best performance with the lowest CV, was less labor intensive than an assay based on ELISA and could therefore be suitable for clinical use.

[Establishing reference intervals of thyroid hormone based on a laboratory information system].

Objective: To establish reference intervals (RIs) of thyroid hormone based on data from healthy subjects in laboratory information system (LIS) by indirect methods. Methods: Data were selected from the physical examination center in LIS of the First Hospital of Jilin University from May 2014 to December 2018. The normal distribution of the original data was checked by the Kolmogorov-Smirnov test. Skewed data were transformed into normal distribution using BOX-COX techniques, and outliers were identified by the Turkey method. The continuous percentile curve was established by coefficient of skewness-median-coefficient of variation(LMS) methods. Cut-off value of age was determined by decision trees, and the differences between groups were verified by Z-tests. P(2.5) and P(97.5) in the RIs were analyzed by non-parametric methods. Results: A total of 45 742 subjects were included in the study. There were no differences in the RI for thyroid stimulating hormone (TSH) among age groups or between men and women (Z

Measurement repeatability profiles of eight frequently requested measurands in clinical chemistry determined by duplicate measurements of patient samples.

Measurement uncertainties in clinical chemistry are commonly regarded as heteroscedastic - having a constant relative standard deviation irrespective of the concentration of the measurand. The uncertainty is usually determined at two concentrations using stabilized control materials and assumed to represent the analytical goal. The purpose of the present study was to use duplicates of unselected patient samples to calculate the absolute and relative repeatability component of the intra-laboratory measurement uncertainty from duplicates, using the Dahlberg formula and analysis of variance components. Estimates were made at five different concentration intervals of ALT, AST, Calcium, Cholesterol, Creatinine, CRP, Triglycerides and TSH covering the entire concentration interval of the patient cohort. This partioning allows detailing their repeatability profiles. The calculations of the profiles were based on randomly selected results from sets of duplicates ranging from 12,000 to 65,000 pairs. The repeatability of the measurands showed substantial variability within the measuring interval. Therefore, characterizing imprecision profiles as purely homo- or heteroscedastic or by a single number may not be optimal for the intended use. The present data make a case for nuancing the evaluation of analytical goals and minimal differences of measurement results by establishing uncertainty profiles under repeatability conditions, using natural patient samples.

Repeatability imprecision from analysis of duplicates of patient samples and control materials.

Measurement imprecision is usually calculated from measurement results of the same stabilized control material(s) obtained over time, and is therefore, principally, only valid at the concentration(s) of the selected control material(s). The resulting uncertainty has been obtained under reproducibility conditions and corresponds to the conventional analytical goals. Furthermore, the commutability of the control materials used determines whether the imprecision calculated from the control materials reflects the imprecision of measuring patient samples. Imprecision estimated by measurements of patient samples uses fully commutable samples, freely available in the laboratories. It is commonly performed by calculating the results of routine patient samples measured twice each. Since the duplicates are usually analysed throughout the entire concentration interval of the patient samples processed in the laboratory, the result will be a weighted average of the repeatability imprecision measured in the chosen measurement intervals or throughout the entire interval of concentrations encountered in patient care. In contrast, the uncertainty derived from many measurements of control materials over periods of weeks is usually made under reproducibility conditions. Consequently, the repeatability and reproducibility imprecision play different roles in the inference of results in clinical medicine. The purpose of the present review is to detail the properties of the imprecision calculated by duplicates of natural samples, to explain how it differs from imprecision calculated from single concentrations of control materials, and to elucidate what precautions need to be taken in case of bias, e.g. due to carry-over effects.

Performance characteristics of automated clinical chemistry analyzers using commercial assay reagents contributing to quality assurance and clinical decision in a hospital laboratory.

Background: Clinical laboratories provide essential diagnostic services that are essential in clinical decision making, contributing to the quality of healthcare. The performance of two Siemens ADVIA 1800 analyzers was characterized in a hospital Biochemistry laboratory in order to evaluate the analytical characteristics of such automated analyzer systems using nonoriginal assay reagents attempting to support laboratory quality service and crucial clinical decision making. Methods: We independently completed performance validation studies including trueness, precision, sensitivity as well as measurement of uncertainty and sigma metrics calculation for 25 biochemical parameters. Results: Trueness expressed as bias was less than 20% for both ADVIA 1800 analyzers. Within run and total precisions expressed as CV% were ≤9.85% on both analyzers for most parameters studied with few exceptions (Mg, TB, DB, Cl, HDL and UA) observed either in low or in high level samples and between the two analyzers. LoB, LoD and LoQ values produced by the two analyzers were comparable except Cl. Uncertainty values produced by the two analyzers were comparable with no significant differences. Quality performance of reagent assays was studied using the sigma metrics system. The sigma values were plotted on normalized method decision charts for graphical representation of assay performances for each analyzer. Conclusions: The two ADVIA systems, independently evaluated, showed consistent performance characteristics with certain discrepancies by several reagents. Sigma analysis was helpful for revealing the quality performance of non-original reagents supporting the need for strict assessment of quality assurance and in some instances optimization/improvement of assay methods.

[Could the publication of new european guidelines change practices in France?] / La publication au JO de nouveaux règlements européens sur les dispositifs médicaux pourrait-elle changer la pratique du diagnostic oncogénétique en France ?

The use of predictive biomarkers in the diagnosis and prediction of the efficacy of targeted therapies for the individualized management of patients is generally based on the use of in vitro medical diagnosis devices that are now covered by the guidelines 90/385/EEC, 93/42/EEC and 98/42/EEC. On 25 May 2017, the European Parliament and Council Regulations 2017/745 and 2017/746 of 5 April 2017, related to medical devices and in vitro medical diagnosis devices, respectively, were published, disrupting years of practices based on European directives. They tend to bring the in vitro diagnosis in Europe closer to the American regulation in order to improve the use of safety diagnosis tests, while the United States have been changing their practices in the face of biomedical, technological and digital evolutions. We will describe the different regulations of diagnostic tests and discuss their applications in the field of oncology.