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The article discusses the differential diagnosis of lymphocytosis using lymphocyte parameters generated by the Sysmex XR-1000 Hematology Analyzer. The study conducted at a hospital laboratory in France aimed to differentiate between reactive and malignant lymphocytosis, focusing on six lymphocyte positional parameters. Results showed that the parameters Ly-X, Ly-Y, and Ly-Z were the most discriminative among different pathological groups, aiding in distinguishing various lymphoproliferative disorders. The study suggests that integrating qualitative and quantitative parameters can improve the accuracy of diagnosing malignant lymphocytosis. [Extracted from the article]

This study aimed to assess the validity of external quality assessment (EQA) laboratory results across various cultural and environmental contexts and to identify potential improvement areas. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Task Force on Global Laboratory Quality (TF-GLQ) conducted a 2-year study (2022 and 2023) in which EQA materials, related software and online training was provided by a commercial vendor to 100 laboratories in ten IFCC member society countries. The results were analysed on a monthly basis by the TF-GLQ, to show the number of submissions per country, tests per lab, acceptability rates, random failures and to get a measure of which analytes performed poorly. The EQA material was dispatched on a quarterly basis. Some countries had problems with customs releasing the material in a timely manner, resulting in laboratories not receiving them on time leading to no submission. We report here the results for the second year of the survey. The number of examinations varied between laboratories, ranging from seven to 84 analytes. Of the ten countries surveyed, six averaged greater than 90 % acceptable results over the whole 12-months cycle, one had unacceptable results for two of the nine months they returned results and the other four were considered to not perform to an acceptable standard. All 100 participating laboratories indicated satisfaction with the EQA survey and related services, including on-site training, and report handling. However, specimen receiving issues, suggest benefits in dispatching materials for a full 12-month cycle. Significant discrepancies in EQA performance indicate that four countries require long-term assistance, training and guidance. To ensure reliable patient results, promoting EQA in certain countries is essential to achieve the required level of quality. [ABSTRACT FROM AUTHOR]

Glycated albumin (GA) has potential value in the management of people with diabetes; however, to draw meaningful conclusions between clinical studies it is important that the GA values are comparable. This study investigates the standardization of the Norudia Glycated Albumin and Lucica Glycated Albumin-L methods. The manufacturer reported imprecision was verified by performing CLSI-EP15-A3 protocol using manufacturer produced controls. The Japanese Clinical Chemistry Reference Material (JCCRM)611-1 was measured 20 times to evaluate the accuracy of both methods. GA was also measured in 1,167 patient samples and results were compared between the methods in mmol/mol and %. Maximum CV for Lucica was ≤0.6 % and for Norudia ≤1.8 % for control material. Results in mmol/mol and % of the JCCRM611-1 were within the uncertainty of the assigned values for both methods. In patient samples the relative difference in mmol/mol between the two methods ranged from −10.4 % at a GA value of 183 mmol/mol to +8.7 % at a GA value of 538 mmol/mol. However, the relative difference expressed in percentage units ranged from of 0 % at a GA value of 9.9 % to +1.7 % at a GA value of 30 %. The results in mmol/mol between the two methods for the patient samples were significantly different compared to the results in %. It is not clear why patient samples behave differently compared to JCCRM611-1 material. Valuable lessons can be learnt from comparing the standardization process of GA with that of HbA1c. [ABSTRACT FROM AUTHOR]

This study performed an analytical validation study of the Mindray high-sensitivity cardiac troponin I (hs-cTnI) assay addressing limit of blank (LoB), limit of detection (LoD), precision, linearity, analytical specificity and sex-specific 99th percentile upper reference limits. LoB, LoD, precision, linearity and analytical specificity were studied according to Clinical and Laboratory Standards Institute. We used one reagent lot and one CL1200i analyzer. Skeletal troponin I and T, cardiac troponin T, troponin C, actin, tropomyosin, myosin light chain, myoglobin and creatine kinase (CK-MB) were studied for cross-reactivity. Interference with biotin was examined. Lithium heparin samples (one freeze thaw cycle) from healthy males and females were measured to determine the 99th percentiles by using the non-parametric method. Analyses were performed before and after excluding subjects with clinical conditions and/or increased surrogate biomarkers. The Mindray hs-cTnI assay met criteria to be considered as a hs-cTn assay. LoB and LoD was <0.1 ng/L and 0.1 ng/L, respectively. Repeatability had a coefficient of variation 1.2–3.8 %, and within-laboratory imprecision 1.7–5.0 %. The measuring interval ranged from 1.1 to 28,180 ng/L. The analytical specificity was clinically acceptable for the interferents studied. After exclusions, the 99th percentile URLs obtained were 10 ng/L overall, 5 ng/L for females and 12 ng/L for males. Analytical observations of the Mindray hs-cTnI assay demonstrated excellent LoB, LoD, precision, linearity and analytical specificity, that were in alignment with the manufacturer's claims and regulatory guidelines for hs-cTnI. The assay is suitable for clinical investigation for patient-oriented studies. [ABSTRACT FROM AUTHOR]

Objective: The detection/identification of clinically significant antibodies to red cell antigens form the foundation for safe transfusion practices. This study aimed to evaluate the diagnostic performance of commercially available 0.8% reagent red blood cells (RRBCs) in Australia. 166 patient-derived plasma samples with a positive indirect antiglobulin test (IAT) were tested using column agglutination technology (CAT) with Immulab, Bio-Rad, Grifols and QuidelOrtho screening and identification RRBCs with the respective manufacturer's proprietary CAT system. Results: False-negative antibody screening and identification results were obtained with Bio-Rad (3/61), Grifols (14/68) and Quidel-Ortho (3/59) RRBCs when tested with the respective manufacturer's proprietary CAT system. Zero false-negative results were observed with Immulab RRBCs when tested with samples across all platforms. The sensitivity of the RRBCs used in this study were calculated to be 95.83% (95%CI 88.30-99.13%) for Bio-Rad RRBCs, 82.50% (95%CI 72.38–90.09%) for Grifols RRBCs and 95.65% (95%CI 87.82–99.09%) for QuidelOrtho RRBCs. The sensitivity of Immulab RRBCs were stratified based on performance in the 3 CAT platforms: Bio-Rad CAT (100%, 95%CI 95.01–100%), Grifols CAT (100%, 95%CI 95.49–100%) and QuidelOrtho CAT (100%, 95%CI 94.79–100%). Conclusions: RRBCs used in antibody detection and identification vary in diagnostic performance and should therefore be carefully considered before being implemented in routine patient testing. [ABSTRACT FROM AUTHOR]

Abstract Objective The detection/identification of clinically significant antibodies to red cell antigens form the foundation for safe transfusion practices. This study aimed to evaluate the diagnostic performance of commercially available 0.8% reagent red blood cells (RRBCs) in Australia. 166 patient-derived plasma samples with a positive indirect antiglobulin test (IAT) were tested using column agglutination technology (CAT) with Immulab, Bio-Rad, Grifols and QuidelOrtho screening and identification RRBCs with the respective manufacturer’s proprietary CAT system. Results False-negative antibody screening and identification results were obtained with Bio-Rad (3/61), Grifols (14/68) and Quidel-Ortho (3/59) RRBCs when tested with the respective manufacturer’s proprietary CAT system. Zero false-negative results were observed with Immulab RRBCs when tested with samples across all platforms. The sensitivity of the RRBCs used in this study were calculated to be 95.83% (95%CI 88.30-99.13%) for Bio-Rad RRBCs, 82.50% (95%CI 72.38–90.09%) for Grifols RRBCs and 95.65% (95%CI 87.82–99.09%) for QuidelOrtho RRBCs. The sensitivity of Immulab RRBCs were stratified based on performance in the 3 CAT platforms: Bio-Rad CAT (100%, 95%CI 95.01–100%), Grifols CAT (100%, 95%CI 95.49–100%) and QuidelOrtho CAT (100%, 95%CI 94.79–100%). Conclusions RRBCs used in antibody detection and identification vary in diagnostic performance and should therefore be carefully considered before being implemented in routine patient testing.

Objectives: This study aimed to evaluate the analytical performance of coagulation tests (prothrombin time (PT/INR), activated partial thromboplastin time (aPTT), fibrinogen, and D-dimer) using the Six Sigma methodology, focusing on identifying areas for improvement to enhance healthcare quality. Methods: Internal quality control (IQC) and external quality control (EQC) data from September 2023 to February 2024 were collected for coagulation parameters analyzed by four Cobas T711 analyzers. Sigma values were calculated using IQC, EQC, and total allowable error (TEa) data. The sigma value for each parameter was calculated according to the formula "(TEa%--bias %)/CV%." The outpatient sample analyzers were labeled A1, A2, and A3. The one that analyzes samples from emergency and intensive care patients was labeled B. Results: Across analyzers A1, A2, A3, and B, sigma values varied for different coagulation parameters. Notably, the D-dimer parameter consistently exhibited excellent performance (sigma >6) for all analyzers. In contrast, some analyzers showed poor performance for aPTT and PT parameters at level 1 (A1 and A3 for aPTT, B for INR). Fibrinogen performance varied, with some analyzers showing excellent performance (sigma >6) and others falling below acceptable levels. Conclusion: By identifying areas of low performance, particularly in aPTT and INR parameters, this study highlights the importance of continuous quality improvement in laboratory testing. Addressing issues identified through the Six Sigma methodology can enhance the reliability of laboratory results and ultimately improve patient care. Further research and initiatives focused on analytical process improvement are needed to achieve higher quality standards in laboratory testing. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) nanobiosensors integrate molecular (bio)recognition elements with semiconductor/plasmonic photoactive nanomaterials to produce measurable signals after light-induced reactions. Recent advancements in PEC nanobiosensors, using light-matter interactions, have significantly improved sensitivity, specificity, and signal-to-noise ratio in detecting (bio)analytes. Tunable nanomaterials activated by a wide spectral radiation window coupled to electrochemical transduction platforms have further improved detection by stabilizing and amplifying electrical signals. This work reviews PEC biosensors based on nanomaterials like metal oxides, carbon nitrides, quantum dots, and transition metal chalcogenides (TMCs), showing their superior optoelectronic properties and analytical performance for the detection of clinically relevant biomarkers. Furthermore, it highlights the innovative role of red light and NIR-activated PEC nanobiosensors in enhancing charge transfer processes, protecting them from biomolecule photodamage in vitro and in vivo applications. Overall, advances in PEC detection systems have the potential to revolutionize rapid and accurate measurements in clinical diagnostic applications. Their integration into miniaturized devices also supports the development of portable, easy-to-use diagnostic tools, facilitating point-of-care (POC) testing solutions and real-time monitoring. [ABSTRACT FROM AUTHOR]

Purpose: To comprehensively investigate the diagnostic performance of routinely used assays in MPXV testing, the National Center of Clinical Laboratories in China conducted a nationwide external quality assessment (EQA) scheme and an evaluated nine assays used by ≥ 5 laboratories in the EQA. Methods: MPXV virus-like particles with 2700, 900 and 300 copies/mL were distributed to 195 EQA laboratories. For extended analysis, triple-diluted samples from 9000 to 4.12 copies/mL were repeated 20 times using the assays employed by ≥ 5 laboratories. The diagnostic performance was assessed by analyzing EQA data and calculating the limits of detection (LODs). Results: The performance was competent in 87.69% (171/195) of the participants and 87.94% (175/199) of the datasets. The positive percentage agreements (PPAs) were greater than 99% for samples at 2700 and 900 copies/mL, and 95.60% (761/796) for samples at 300 copies/mL. The calculated LODs for the two clades ranged from 228.44 to 924.31 copies/mL and were greater than the LODs specified by the respective kits. EasyDiagnosis had the lowest calculated LODs and showed superior performance in EQA, whereas BioGerm and Sansure, with higher calculated LODs, did not perform well in EQA. Conclusion: This study provides valuable information from the EQA data and evaluation of the diagnostic performance of MPXV detection assays. It also provided insights into reagent optimization and enabled prompt public health interventions for the outbreak. [ABSTRACT FROM AUTHOR]

Analytical performance specifications (APS) based on outcomes refer to how 'good' the analytical performance of a test needs to be to do more good than harm to the patient. Analytical performance of a measurand affects its clinical performance. Without first setting clinical performance requirements, it is difficult to define how good analytically the test needs to be to meet medical needs. As testing is indirectly linked to health outcomes through clinical decisions on patient management, often simulation-based studies are used to assess the impact of analytical performance on the probability of clinical outcomes which is then translated to Model 1b APS according to the Milan consensus. This paper discusses the related key definitions, concepts and considerations that should assist in finding the most appropriate methods for deriving Model 1b APS. We review the advantages and limitations of published methods and discuss the criteria for transferability of Model 1b APS to different settings. We consider that the definition of the clinically acceptable misclassification rate is central to Model 1b APS. We provide some examples and guidance on a more systematic approach for first defining the clinical performance requirements for tests and we also highlight a few ideas to tackle the future challenges associated with providing outcome-based APS for laboratory testing. [ABSTRACT FROM AUTHOR]

Abstract Hemoglobin A1c (HbA1c) plays a crucial role in diabetes management. We aimed to evaluate the analytical performance of a new enzymatic method kit for HbA1c measurement. The performance of the enzymatic method, including precision, accuracy, and linearity, was evaluated. Moreover, the interference effect from conventional interferents, Hb derivatives, Hb variants, and common drugs were assessed. In addition, the agreement of HbA1c results was compared between enzymatic methods, cation-exchange high-performance liquid chromatography (HPLC), and immunoassays. The intra-assay, between-assay, and total precision of HbA1c were all lower than 2%. HbA1c showed good linearity within the range of 3.96–20.23%. The enzymatic assay yielded results consistent with the external quality control samples, with a bias of less than ± 6% from the target values. The enzymatic method showed no interference from bilirubin, intralipid, vitamin C, Hb derivatives, common Hb variants, as well as antipyretic analgesics and hypoglycemic drugs. The HbA1c results of the enzymatic assay showed good agreement and accuracy compared to those obtained from the HPLC method and the immunoassay. The enzymatic method kit performed on the BS-600M chemistry analyzer is a reliable and robust method for measuring HbA1c. It is suitable for routine practice in clinical chemistry laboratories.

In April 2020, the Aboriginal and Torres Strait Islander COVID-19 Point-of-Care (POC) Testing Program was initiated to improve access to rapid molecular-based SARS-CoV-2 detection in First Nations communities. At capacity, the program reached 105 health services across Australia. An external review estimated the program contributed to averting between 23,000 and 122,000 COVID-19 infections within 40 days of the first infection in a remote community, equating to cost savings of between AU$337 million and AU$1.8 billion. Essential to the quality management of this program, a customised External Quality Assessment (EQA) program was developed with the Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP). From July 2020 to May 2022, SARS-CoV-2 EQA participation ranged from 93 to 100%. Overall concordance of valid EQA results was high (98%), with improved performance following the first survey. These results are consistent with those reported by 12 Australian and 4 New Zealand laboratories for three SARS-CoV-2 RNA EQA surveys in March 2020, demonstrating that SARS-CoV-2 RNA POC testing in primary care settings can be performed to an equivalent laboratory analytical standard. More broadly, this study highlights the value of quality management practices in real-world testing environments and the benefits of ongoing EQA program participation. [ABSTRACT FROM AUTHOR]

Monitoring is indispensable for assessing disease prognosis and evaluating the effectiveness of treatment strategies, both of which rely on serial measurements of patients' data. It also plays a critical role in maintaining the stability of analytical systems, which is achieved through serial measurements of quality control samples. Accurate monitoring can be achieved through data collection, following a strict preanalytical and analytical protocol, and the application of a suitable statistical method. In a stable process, future observations can be predicted based on historical data collected during periods when the process was deemed reliable. This can be evaluated using the statistical prediction interval. Statistically, prediction interval gives an "interval" based on historical data where future measurement results can be located with a specified probability such as 95%. Prediction interval consists of two primary components: (i) the set point and (ii) the total variation around the set point which determines the upper and lower limits of the interval. Both can be calculated using the repeated measurement results obtained from the process during its steady-state. In this paper, (i) the theoretical bases of prediction intervals were outlined, and (ii) its practical application was explained through examples, aiming to facilitate the implementation of prediction intervals in laboratory medicine routine practice, as a robust tool for monitoring patients' data and analytical systems. [ABSTRACT FROM AUTHOR]

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Background: AMH is important in child growth and the concentrations change with age and gender. This study aimed to evaluate the performance of the Pylon AMH assays and establish pediatric reference intervals. Methods: The experiments on imprecision, sensitivity, linearity, reportable range, interference and comparison were carried out to evaluate the analytical performance. The AMH reference ranges were calculated in 238 females and 346 males aged 0–18 years using robust methods. Results: The repeatability and the within-laboratory imprecision CVs of the assay were 3.7 % and 6.4 % at 2.25 ng/mL, and 4.6 % and 6.4 % at 15.49 ng/mL, respectively. The sensitivity (LoB = 0.05 ng/mL, LoD = 0.1 ng/mL and LoQ = 0.3 ng/mL) was verified. The linearity was 0.1–19.55 ng/mL and report up to 391 ng/mL with 20x pre-dilution. There was no significant interference from hemoglobin (500 mg/dL), triglyceride (500 mg/dL), bilirubin (10 mg/dL), cholesterol (800 mg/dL) and biotin (3000 ng/mL). The AMH measured by the Pylon assays correlated to those measured by the Elecsys assays. In males, the AMH levels were high at birth (0 d-1 m: median 95.10 ng/mL) and increased to a peak (7 m-1y: median 158.80 ng/mL) before they decreased with age (15–18 y: median 6.31 ng/mL). In females, the AMH concentrations were low at birth (0 d-1 m: median 0.20 ng/mL) and increased with age (15–18 y: median 3.03 ng/mL). Conclusion: The Pylon AMH assays showed good analytical performance and the AMH reference intervals in chinese children determined may provide a basis in clinical diagnosis and treatment of related diseases.

Vacuum-assisted headspace solid-phase microextraction (Vac-HS-SPME) could provide an alternative for extracting pesticides from grape samples. Vac-HS-SPME method is utilized to the simultaneous analysis of six pesticides from various classes, namely boscalid, quizalofop-p-methyl, oxyfluorfen, fluroxypyr-meptyl, metribuzin and epoxiconazole. In this study investigated and optimized the impact of independent variables, such as extraction temperature, extraction time, fiber coating, incubation time, salt effect, sample volume, air evacuation time, pH, desorption time with the objective of achieving lower detection limits (ranging from 0.11 to 0.61 µg mL-1) and effective analyte responses. Moreover, in this work a comparison was made between classical solid phase microextraction and vacuum-assisted solid phase microextraction for the extraction of pesticides in grape samples under the same parameters. The results clearly demonstrated that the combination of Vac-HS-SPME proved to be more appropriate and selective for the extraction of pesticides from grape samples.

This article discusses the challenges faced by Contract Research Organizations (CROs) in complying with the European Union's Regulation (EU) 2017/746 on In Vitro Diagnostic Devices (IVDR). CROs play a crucial role in assisting manufacturers of IVDs in navigating the complex regulatory requirements. Compliance with the IVDR requires specialized expertise in areas such as clinical research, data management, and risk assessment. CROs can provide guidance and support to manufacturers in areas such as clinical performance evaluation, access to human specimens for validation, and analytical and clinical performance assessment. CROs that are part of a larger medical laboratory group have access to reference assays and instruments, ensuring high-quality standards. ISO 15189-certified laboratories offer a controlled environment for data quality. CROs can also provide regulatory counseling and utilize innovative digital systems to simplify data collection and analysis. Compliance with the IVDR is crucial for ensuring the safety and efficacy of IVDs in the European market, and CROs are valuable partners in this process. [Extracted from the article]

Objectives This study aimed to evaluate the analytical performance of the cobas 6800 System (Roche Diagnostics) and assess the feasibility of using whole-blood specimens instead of plasma. Methods The analytical performance of the cobas EBV test (Roche Diagnostics) was evaluated. Thereafter, 120 clinical samples were collected to compare the cobas EBV test and the artus EBV RG PCR Kit (Qiagen). The results of the cobas EBV test conducted using paired plasma as well as 5× and 10× diluted whole-blood specimens were compared with those of the artus EBV RG PCR Kit performed using whole blood. Results The precision of the cobas EBV test was acceptable, and its linearity was confirmed to be within the range of 2.85 to 6.89 log IU/mL. Cross-reactivity was not observed. The best qualitative agreement (Cohen κ = 0.733) was observed using 5× diluted whole blood; the best quantitative correlation (Spearman correlation coefficient = 0.6865) was observed using 10× diluted whole blood. Conclusions A significant discrepancy was observed in the results obtained from the 2 assays because of the different specimens used. We observed, however, that diluting whole blood before conducting the cobas EBV test effectively resolved polymerase chain reaction inhibition and viscosity issues, leading to an acceptable correlation with the results from the artus EBV RG PCR Kit conducted using whole blood. [ABSTRACT FROM AUTHOR]

Cardiac troponin (cTn) is the key biomarker for diagnosis of acute coronary syndrome (ACS). We performed a complete assessment of the high-sensitivity cardiac troponin I (hs-cTnI) (CLIA) assay on the analytical performance and clinical diagnostic performance, which was compared with Abbott ARCHITECT hs-cTnI assay. Sex-specific 99th percentile upper reference limits (URLs) were determined from a healthy population of 424 males and 408 females. High-sensitivity performance was assessed by examining the imprecision at sex-specific URLs and the detectable results above LoD in a cohort of healthy population. The diagnostic performance of the hs-cTnI (CLIA) assay was validated in a population of 934 patients with suspected ACS. The 99th percentile URLs were 15.3 ng/L for female, 31.3 ng/L for male and 24.2 ng/L for overall population. The total imprecision near the sex-specific 99th percentile URLs were <5 %. 76.74 % of females, 97.12 % of males and 86.69 % of overall population had cTnI values exceeding the LoD, which met the criteria of high-sensitivity troponin assay. No cross-reactivity or interference was identified. The diagnostic sensitivity, specificity, PPV, NPV, and AUC of hs-cTnI (CLIA) assay were 97.97 , 90.70, 79.02, 99.21 % and 0.9885, respectively, which were comparable to ARCHITECT hs-cTnI assay. hs-cTnI (CLIA) assay is a high-sensitivity troponin I method with high precision, sensitivity and specificity. The clinical diagnostic performance of hs-cTnI (CLIA) is comparable to the established ARCHITECT hs-cTnI assay. Mindray's hs-cTnI (CLIA) assay is an attractive alternative for diagnosis of myocardial infarction with a high level of accuracy and safety. [ABSTRACT FROM AUTHOR]

In this study, we present a novel and ultrasensitive magnetic lateral flow immunoassay (LFIA) tailored for the precise detection of zearalenone, a mycotoxin with significant implications for human and animal health. A versatile and straightforward method for creating non-covalent magnetic labels is proposed and comprehensively compared with a covalent immobilization strategy. We employ the magnetic particle quantification (MPQ) technique for precise detection of the labels and characterization of their functionality, including measuring the antibody sorption density on the particle surface. Through kinetic studies using the label-free spectral phase interferometry, the rate and equilibrium constants for the binding of monoclonal antibodies with free (not bound with carrier protein) zearalenone were determined to be kon = 3.42 × 105 M−1s−1, koff = 7.05 × 10−4 s−1, and KD = 2.06 × 10−9 M. The proposed MPQ-LFIA method exhibits detection limits of 2.3 pg/mL and 7.6 pg/mL when employing magnetic labels based on covalent immobilization and non-covalent sorption, with dynamic ranges of 5.5 and 5 orders, correspondingly. We have successfully demonstrated the effective determination of zearalenone in barley flour samples contaminated with Fusarium graminearum. The ease of use and effectiveness of developed test systems further enhances their value as practical tools for addressing mycotoxin contamination challenges. [ABSTRACT FROM AUTHOR]

Background: Most glycated hemoglobin A1c (HbA1c) analytical reagents used were obtained from the analyzer's manufacturer. However, clinical laboratories need more choices for HbA1c analytical reagents to overcome the limitations of dedicated reagents for special analyzers. We developed new mobile phase buffers as HbA1c diagnostic reagents and evaluated their analytical performance for the HbA1c assay. Methods: Different mobile phase buffers used as HbA1c diagnostic reagents were prepared using different concentrations of sodium salts. According to the Clinical and Laboratory Standards Institute (CLSI) recommendation guidelines, the analytical performances of the newly developed mobile phase buffers were evaluated on an ARKRAY HA-8160 Analyzer. Both quality controls and clinical blood samples were used in these experiments. To assess the quality of the newly developed mobile phase buffers, precision, accuracy, linearity, carryover, interference, bias, correlation with commercial reagents, and stability were analyzed. Results: The CVs of intra-assay precision and interassay precision of quality control and clinical.There were fewer than 1.00 % blood sample assays using the newly developed mobile phase buffer. The RDs of accuracy were less than 1.00 %. Linearity: R2 = 0.9998 in the concentration range of 4.40%–17.30 %. Carryover: 0.00 %. Reagent comparison revealed that the Pearson regression equation was Y = 0.9884x+0.05692 (R2 = 0.9977), and the Bland-Altman mean difference was −0.02650 % (CI: −0.2121 %–0.1591 %) between the two analytical reagents. Stability was also acceptable within 12 months. This mobile phase buffer showed good anti-interference ability. Conclusion: The newly developed mobile phase buffers demonstrated good analytical performance and were suitable for clinical HbA1c assays on an ARKRAY HA-8160 Analyzer.

Dereje Mengesha Berta,1 Mulugeta Melku,1,2 Tiruneh Adane,1 Mekonnen Girma,3 Zewudu Mulatie,4 Elias Chane,5 Bisrat Birke Teketelew1 1Department of Hematology and Immunohematology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia; 2College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia; 3Department of Quality Assurance and Laboratory Management, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia; 4Department of Medical Laboratory Science, Wollo University, Wollo, Ethiopia; 5Department of Clinical Chemistry, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, EthiopiaCorrespondence: Dereje Mengesha Berta, Department of Hematology and Immunohematology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, PO Box 196, Gondar, Ethiopia, Tel +251910594497, Email mengeshad826@gmail.comIntroduction: In clinical laboratory, the performance of the hematology analyzer should be checked routinely to ensure the desired quality. Therefore, the aim of the study was to assess the analytical performance of hematology analyzer using sigma metrics.Methods: The study included all daily internal quality control (IQC) data of hematology analyzer prospectively from August to October 2022. Data was collected using record formats by trained laboratory professionals. The sigma values of each CBC parameter were calculated using the formula: Sigma = (TEa – Bias) / CV. The TEa data were adopted from five different guidelines to calculate sigma value of the laboratory based on different specification. The bias of all complete blood count (CBC) parameters was calculated from the laboratory mean of the daily IQC data and the target value of the manufacturer in the insert kit. A coefficient of variations was also calculated using IQC data.Results: The current study found that sigma value of the analyzer varied based on source of TEa. Except HCT out 5 parameters included based on CLIA guideline, except MCV, MCHC, RDW, MPV and Basophil out of 15 parameters included based on EFLM 2022 minimum guideline, except Hb and PLT out of 9 parameters included based on SOTA guideline other parameters meets minimum specification (< 3 sigma value). On the other hand, all parameters included in Rilibak and Standards of Spanish guideline achieved minimum specification (> 3 sigma value).Conclusion: Sigma values of the CBC parameters have significantly varied depends on the TEa sources. So, it is recommended laboratory to use alternative sigma value based on its preference. Additionally, it is suggested that the laboratory to design local Westgard rules for each parameter based on sigma value.Keywords: analytical performance, hematology, laboratory, sigma metrics

We introduce an innovative approach to enhance the quantification of the pesticide imidacloprid (IMD) using square wave voltammetry (SWV) with a mercury drop electrode (HMDE). Through systematic factorial designs, we meticulously adjusted both the chemical and instrumental parameters of SWV, with a particular focus on optimizing the peak reduction current. Using response surface methodology (RSM) provided comprehensive insights into the system behavior. The optimal conditions were found at a pH of IMD solution of 7.45, Accumulation Potential (Eacc) of −0.70 V, Accumulation Time (tacc) of 46.45 s, Frequency (F) of 200 Hz, Amplitude (Esw) of 0.090 V, and Step (dE) of 0.0080 V. With these optimized parameters, we constructed a calibration curve spanning a concentration range from 0.5 to 5.0 × 10-7 mol/L. The method exhibited a remarkably low limit of detection (LOD) at 3.65 × 10-8 mol/L and a limit of quantification (LOQ) of 5.01 × 10-8 mol/L. Subsequently, we rigorously assessed the methodology's effectiveness by quantifying IMD in various water samples from the Córdoba area, achieving consistently near 100 % recovery values.

Biochemical analyzers are vital instruments that utilize the principle of photoelectric colorimetry to quantify a specific chemical composition in body fluids. This analysis provides critical data for the diagnosis, treatment, prognosis, and overall health status of various diseases in clinical practice. However, the performance of a biochemical analyzer can vary significantly between different brands or over time within the same brand. Therefore, it is imperative to regularly assess the performance of the analyzer to ensure consistent results for longitudinal studies and to maintain day-to-day data consistency. Additionally, when multiple analyzers are utilized, it is necessary to evaluate the performance of each instrument to ensure accurate results across multiple platforms. In this study, we developed and verified an experimental evaluation scheme for the analytical performance of the instrument, chemometrics for biochemical analyzers, utilizing national reference materials and patient sera as the experimental subjects. We evaluated the performance of the optical system, temperature control system, sample-adding system, and detection system to confirm the feasibility of this scheme. We also compared the analytical performance of different brands of biochemical analyzers for routine biochemical tests, such as liver function, kidney function, ion, blood lipids, blood glucose, and myocardial enzyme spectrum. Using the AU 5400 as a control and the ADVIA 2400 as the comparison system, the relative variation in inter-instrument comparison data was found to be acceptable at the clinical medicine decision level. In conclusion, the performance of a biochemical analyzer can vary significantly between different brands or over time within the same brand. Regular evaluations are necessary to ensure accurate and consistent results across different analyzers. This study provides a feasible scheme for evaluating the analytical performance of biochemical analyzers that can be used to ensure the accuracy and consistency of the results of different brands of automatic chemical analyzers in the laboratory.

The sigma metric offers a quantitative framework for evaluating process performance in clinical laboratories. This study aimed to evaluate the analytical performance of automated analysers in haematology laboratories, using the sigma metric to choose the best analyser as an internal reference analyser. internal quality control (IQC) data were collected for 6 months from SNCS, and the sigma value was calculated for 9 haematology analysers in the laboratory. For the normal control level, a satisfactory mean sigma value ≥3 was observed for all of the studied parameters of all automated analysers. For the low control level, platelet (PLT) count by Instrument (Inst.) G performed poorly, with a mean sigma value <3. Inst. H, with all parameters' sigma values >4, performed best and was chosen as the internal reference analyser. The sigma metric can be used as a guide to choose the QC strategy and plan QC frequency. It can facilitate the comparison of the same assay performed by multiple systems. [ABSTRACT FROM AUTHOR]

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen detection is an indispensable tool for epidemic surveillance in the post-pandemic era. Faced with irregular performance, a comprehensive external quality assessment (EQA) scheme was conducted by the National Center for Clinical Laboratories (NCCL) to evaluate the analytical performance and status of SARS-CoV-2 antigen tests. The EQA panel included ten lyophilized samples containing serial 5-fold dilutions of inactivated SARS-CoV-2-positive supernatants of the Omicron BA.1 and BA.5 strains and negative samples, which were classified into "validating" samples and "educational" samples. Data were analyzed according to qualitative results for each sample. A total of 339 laboratories in China participated in this EQA scheme, and 378 effective results were collected. All validating samples were correctly reported by 90.56 % (307/339) of the participants and 90.21 % (341/378) of the datasets. The positive percent agreement (PPA) was >99 % for samples with concentrations of 2 × 107 copies/mL but was 92.20 % (697/756) for 4 × 106 copies/mL and 25.26 % (382/1,512) for 8 × 105 copies/mL samples. Colloidal gold was the most frequently used (84.66 %, 320/378) but showed the lowest PPAs (57.11 %, 1,462/2,560) for positive samples compared with fluorescence immunochromatography (90 %, 36/40) and latex chromatography (79.01 %, 335/424). Among 11 assays used in more than 10 clinical laboratories, ACON showed a higher sensitivity than other assays. The EQA study can help to validate whether it's necessary to update antigen detection assays for manufacturers and provide participants with information about the performance of assays to take the first step toward routine post-market surveillance. [ABSTRACT FROM AUTHOR]

Measurement of plasma albumin is pivotal for clinical decision-making in patients with chronic kidney disease (CKD). Routinely used methods as bromocresol green (BCG) and bromocresol purple (BCP) can suffer from aselectivity, but the impact of aselectivity on the accuracy of plasma albumin results of CKD-patients is still unknown. Therefore, we evaluated the performance of BCG-, BCP- and JCTLM-endorsed immunological methods in patients with various stages of CKD. We evaluated the performance of commonly used albumin methods in patients with CKD stages G1 through G5, the latter divided in two groups based on whether they received hemodialysis treatment. In total, 163 patient plasma samples were measured at 14 laboratories, on six different BCG and BCP-platforms, and four different immunological platforms. The results were compared with an ERM-DA-470k-corrected nephelometric assay. The implications on outcome is evaluated by the proportion of patient results <38 g/L for the diagnosis of protein energy wasting. Albumin results determined with BCP- and immunological methods showed the best agreement with the target value (92.7 and 86.2 %, respectively vs. 66.7 % for BCG, namely due to overestimation). The relative agreement of each method with the target value was platform-dependent, with larger variability in agreement between platforms noted for BCG and immunological methods (3.2–4.6 and 2.6–5.3 %) as opposed to BCP (0.7–1.5 %). The stage of CKD had similar effects on the variability in agreement for the three method-groups (0.6–1.8 % vs. 0.7–1.5 % vs. 0.4–1.6 %). The differences between methods cause discrepancies in clinical decision-making, as structurally fewer patients were diagnosed with protein energy wasting upon using BCG-based albumin results. Our study shows that BCP is fit for the intended use to measure plasma albumin levels in CKD patients from all stages, including patients on hemodialysis. In contrast, most BCG-based platforms falsely overestimate the plasma albumin concentration. [ABSTRACT FROM AUTHOR]

In April 2020, the Aboriginal and Torres Strait Islander COVID-19 Point-of-Care (POC) Testing Program was initiated to improve access to rapid molecular-based SARS-CoV-2 detection in First Nations communities. At capacity, the program reached 105 health services across Australia. An external review estimated the program contributed to averting between 23,000 and 122,000 COVID-19 infections within 40 days of the first infection in a remote community, equating to cost savings of between AU$337 million and AU$1.8 billion. Essential to the quality management of this program, a customised External Quality Assessment (EQA) program was developed with the Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP). From July 2020 to May 2022, SARS-CoV-2 EQA participation ranged from 93 to 100%. Overall concordance of valid EQA results was high (98%), with improved performance following the first survey. These results are consistent with those reported by 12 Australian and 4 New Zealand laboratories for three SARS-CoV-2 RNA EQA surveys in March 2020, demonstrating that SARS-CoV-2 RNA POC testing in primary care settings can be performed to an equivalent laboratory analytical standard. More broadly, this study highlights the value of quality management practices in real-world testing environments and the benefits of ongoing EQA program participation.

ABSTRACTIntroduction The sigma metric offers a quantitative framework for evaluating process performance in clinical laboratories. This study aimed to evaluate the analytical performance of automated analysers in haematology laboratories, using the sigma metric to choose the best analyser as an internal reference analyser.Materials and Methods internal quality control (IQC) data were collected for 6 months from SNCS, and the sigma value was calculated for 9 haematology analysers in the laboratory.Results For the normal control level, a satisfactory mean sigma value ≥3 was observed for all of the studied parameters of all automated analysers. For the low control level, platelet (PLT) count by Instrument (Inst.) G performed poorly, with a mean sigma value 4, performed best and was chosen as the internal reference analyser.Conclusion The sigma metric can be used as a guide to choose the QC strategy and plan QC frequency. It can facilitate the comparison of the same assay performed by multiple systems.

We evaluated the overall performance of the Cobas 6800 BKV test in detecting BK virus (BKV). We examined the imprecision of the Cobas 6800 BKV test and compared the qualitative and quantitative results obtained from the Cobas 6800 BKV test and the Real-Q BKV quantification assay. We assessed 88 plasma and 26 urine samples collected between September and November 2022 from patients with BKV infection using the Real-Q BKV quantitative assay. The lognormal coefficient of variation indicated that the inter-assay precision of the Cobas 6800 BKV test ranged from 13.86 to 33.83%. A strong correlation was observed between the quantitative results obtained using the Cobas 6800 BKV test and the Real-Q BKV quantification assay for plasma samples. The Spearman's rank correlation coefficients (ρ) for plasma, polymerase chain reaction (PCR) media-stabilized urine, and raw urine samples were 0.939, 0.874, and 0.888, respectively. Our analyses suggest that the Cobas 6800 BKV test is suitable for clinical applications owing to the strong correlation between the results obtained using this test and the Real-Q BKV quantification assay in plasma and urine samples. Furthermore, utilizing fresh raw urine samples can be a viable approach for the Cobas 6800 BKV test as it is less labor- and time-intensive. [ABSTRACT FROM AUTHOR]

Scientific knowledge should be based on evidence. However, some scientific studies can be carried out without sufficient evidence. And these studies may mislead subsequent studies. Ischemia-modified albumin (IMA) is a relatively newly proposed biomarker. It is used not only for myocardial ischemia but also used for other pathological conditions in the body. IMA is commonly measured by albumin cobalt binding (ACB) assay. ACB is a simple colorimetric assay performed in patients’ sera. It is claimed that because of the ischemia or ischemia-reperfusion, the molecular structure of the N-terminus of human serum albumin is changed and therefore it cannot bind metal ions and cobalt ions added into the reaction mixture react with dithiothreitol to give a brown color. The clinical performance of the ACB assay is poor and it has not a strong correlation with other ischemia biomarkers. There are many analytical uncertainties in ACB assay and IMA as well. Despite the uncertainties, the ACB assay is still commonly used for many research studies. Therefore the theory of the ACB assay should be questioned. In this opinion paper, we discussed these uncertainties. In conclusion, there is insufficient evidence for the existence of IMA as a biomarker. The ACB assay essentially measures serum albumin concentration. There are many other interfering factors with the ACB assay. Therefore, the measurement of IMA in any pathological condition is a useless effort.

Background: The clinical utility of circulating tumor DNA (ctDNA) in the early detection of tumor mutations for targeted therapy and the monitoring of tumor recurrence has been reported. However, the analytical validation of ctDNA assays is required for clinical application. Methods: This study evaluated the analytical performance of the Oncomine Lung cfDNA Assay compared with the cobas® EGFR Mutation Test v2. The analytical specificity and sensitivity were estimated using commercially pre-certified reference materials. The comparative evaluation of the two assays was carried out using reference materials and plasma derived from patients diagnosed with lung cancer. Results: Using 20 ng of input cell-free DNA (cfDNA), the analytical sensitivities for EGFR mutations with variant allele frequencies (VAFs) of 1% and 0.1% were 100% and 100%, respectively. With VAFs of 1.2% and 0.1% using 20 ng of input cfDNA, seven out of nine different mutations in six driver genes were identified in the Oncomine Lung cfDNA Assay. The two assays showed 100% concordance in 16 plasma samples clinically. Furthermore, various PIK3CA and/or TP53 mutations were identified only in the Oncomine Lung cfDNA Assay. Conclusions: The Oncomine Lung cfDNA Assay can be used to identify plasma EGFR mutations in patients with lung cancer, although further large-scale studies are required to evaluate the analytical validity for other types of aberrations and genes using clinical samples. [ABSTRACT FROM AUTHOR]

In May 2022, the European Regulation 2017/746 (IVDR) came into force. It changes the approach of in vitro medical devices (IVD-MDs) for industry and institutions. It reinforces the clinical evidence requirements to improve performance, safety and transparency. Despite extended transition periods and existing guides, IVDR remains difficult to interpret and bringing devices into compliance requires efforts. The generation of clinical evidence is essential to demonstrate compliance with IVDR, and encompasses scientific validity, analytical performance and clinical performance. It is required to demonstrate, per intended use in the target population and clinical care pathway, IVD-MDs clinical performance (compared to a predefined clinical performance). Thus, there is a need for IVD-manufacturers and end-users in health care institutions, to obtain guidance on how to generate this clinical evidence. This article aims industrials and clinicians to identify key steps imposed by the IVDR for bringing IVD-MDs to the EU-market. We propose a general view of performance evaluation requirements for IVD-MDs and provide key references, including how to establish study design that will enable to document clinical performance of existing, refined or emerging medical tests. Finally, we propose a roadmap to address the relevant questions and studies in relation to the documents requested in the IVDR. [ABSTRACT FROM AUTHOR]

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has become a common technique in clinical laboratories in recent years. Because most methods are laboratory-developed tests (LDTs), their reproducibility and quality control (QC) have been controversial. In this study, Westgard Sigma Rules were used to evaluate the analytical performance and establish an individualised internal QC (IQC) strategy for these LDTs. Taking the LC-MS/MS LDT method for homocysteine (Hcy) as an example, the 'desirable specifications' from the Biological Variation Database were used as quality goals. Based on the external quality assessment (EQA) samples, bias was calculated and the coefficient of variation (CV) was also calculated by IQC measurements for six consecutive months. The analytical performance was evaluated by calculated sigma metrics and an IQC strategy was designed using the Westgard Sigma Rules with run size. Over 116 days within 6 months, a total of 850 data points were collected for each of IQC 1 and IQC 2. The monthly coefficient of variation CV% was 2.57–4.01%, which was non-significant (p-value: 0.75). The absolute bias% for IQC1 and IQC2 was 1.23 and 1.87%, respectively. The allowable total error (TEa) was selected as 15.5%, Sigma metrics were 4.02 and 4.30, and the analytical performance was 'Good'. The 13s/22s/R4s/41s multi rules (n=4, r=1) with a run size of 200 samples were suggested for the Hcy IQC scheme. The quality goal index (QGI) values were over 1.2, indicating that trueness needed to be improved. The analytical performance of the Hcy LC-MS/MS LDT conformed to the Six Sigma rating level, achieving 'good' (four Sigma). Clinical practice indicated that calibration bias was the primary factor affecting trueness. [ABSTRACT FROM AUTHOR]

Food safety poses a threat to public health and raises serious concerns worldwide. Contaminants include various substances such as pathogens, toxins, pesticides and heavy metals. Therefore, food safety detection is an urgent need. Recently, dual-mode sensors have ensured the accuracy of assay results by integrating two signals into one, demonstrating their potential application in primary food safety screening tests and quantitative assays. In particular, visible optical signals from dual-mode sensors can satisfy the need for onsite contaminant monitoring. Although dual-mode sensors have been an area of growing interest, the design strategies for sensors tailored to food contaminants are rarely highlighted and discussed. Herein, we review the five-year progress in dual-mode optical detection methods for food contaminants. In particular, this article focuses on exploring the various sensing performances of dual-mode sensors, including the types, sensing principles, advanced design strategies, and applications. Finally, the current challenges and future developments in dual-mode sensors are briefly discussed. Integrated dual-mode optical sensors have received considerable attention regarding food safety. Compared with a single signal, the multichannel biosensor can essentially eliminate the influence of the complex food matrix and reduce false positives and negatives; signals can be statistically tested to verify the reliability of the results. Food safety poses a threat to public health and raise a continuing great concern around the world. Pathogens, mycotoxins, pesticides, heavy metals and other substances are mainly contaminants in food. There is a great need for the onsite real time food safety detection. To satisfy the need, dual-mode sensor ensures the accuracy and reliability of assay results by integrating two signals from one, showing great potential application in food safety primary screening test and quantitative detection. Especially, one of the readout signals from many of the dual-mode sensors is visible by naked-eye, which will satisfy the need for onsite facile monitoring of food contaminants. Herein, we reviewed the five-year progress of dual-mode detection methods for food contaminants. The types of dual-mode detection, the sensing principle, the advanced design strategy, and the applications of dual-mode sensors in different food contaminants are summarized. Finally, the current challenges and future development of dual-mode sensor are briefly prospected. [Display omitted] • The types, sensing principle, and design strategy of dual-mode detection are presented. • The applications of dual-mode sensors in different food contaminants are summarized. • The current challenges and future development of dual-mode sensor are briefly prospected. [ABSTRACT FROM AUTHOR]

• Analytical characteristics of whole blood POC Atellica VTLi compared to plasma central laboratory Atellica IM hs-cTnI assays. • Moderate to strong concordance between whole blood point of care Atellica VTLi hs-cTnI to plasma central laboratory assay. • Lack of standardization between POC and central laboratory hs-cTnI assays prevents interchanged use in patient care. This study examined the analytical performance of a whole blood (WB) point of care (POC) hs-cTnI assay compared to a plasma central laboratory hs-cTnI assay in patients presenting with ischemic symptoms to a US emergency department. Fresh WB specimens collected at 0 and 2 h from 1089 consecutive patients (2152 total from 1076 matched specimens) were analyzed for hs-cTnI using WB on POC Siemens Atellica VTLi assay and plasma on central laboratory Siemens Atellica IM assay. Concordances were determined based on concentrations ranging from < limit of detection (LoD), LoD to overall and sex specific 99th percentiles from both the IFCC manufacturer package inserts and Universal Sample Bank (USB) data, and > 99th percentiles. Method comparisons were calculated using Passing Bablok regression and Bland Altmann plots, and linear regression determined by Pearson correlation coefficient. Baseline concentration comparisons showed: POC VTLi < LoD 4–5 %, ≥ LoD 95 %; Atellica IM < LoD 5–7 %, and ≥ LoD 94–95 %. From the 2152 paired 0 and 2-hour samples, based on 99th percentiles, overall concordance was 91–92 % (kappa 0.72–0.77) and discordance 8 %. Passing Bablok regression analysis using 1924 specimens between LoD to 500 ng/L showed: slopes 0.469–0.490; y-intercepts 1.753–2.028; r values 0.631–0.817. Pearson correlation coefficient showed moderate to strong correlation strength, even with up to 53 % cTnI concentrations variance (Passing Bablok slopes) vs 27.0–40.1 % (Bland-Altmann plots). Up to 95 % of measured samples were > LoD for both the POC (Atellica VTLi) and central laboratory (Atellica IM) hs-cTnI assays. Moderate to strong concordance and correlation were observed between assays, despite up to 53 % variances in cTnI concentration. [ABSTRACT FROM AUTHOR]

• A six sigma model was successfully applied for the quality management of CSF biochemical analytes. • We evaluated the analytical performance of CSF biochemical analytes using the six sigma model and formulated individualized IQC procedures. • We provided appropriate improvement measures for the CSF biochemical analytes with a sigma less than 6. In this study, we applied a six sigma model to examine cerebrospinal fluid (CSF) biochemical analytes for the first time. Our goal was to evaluate the analytical performance of various CSF biochemical analytes, design an optimized internal quality control (IQC) strategy, and formulate scientific and reasonable improvement plans. The sigma values of CSF total protein (CSF-TP), albumin (CSF-ALB), chloride (CSF-Cl), and glucose (CSF-GLU) were calculated using the following formula: sigma = [TEa(%)−|bias(%)|]/CV(%). The analytical performance of each analyte was shown using a normalized sigma method decision chart. Individualized IQC schemes and improvement protocols for CSF biochemical analytes were formulated using the Westgard sigma rule flow chart with batch size and quality goal index (QGI). The distribution of sigma values for CSF biochemical analytes ranged from 5.0 to 9.9, and the sigma values varied for different concentrations of the same analyte. The analytical performance of the CSF assays at the two QC levels is displayed visually in normalized sigma method decision charts. Individualized IQC strategies for CSF biochemical analytes were as follows: for CSF-ALB, CSF-TP and CSF-Cl, use 1 3s with N = 2 and R = 1000; for CSF-GLU, use 1 3s /2 2s /R 4s with N = 2 and R = 450. In addition, priority improvement measures for analytes with sigma values less than 6 (CSF-GLU) were formulated based on the QGI, and their analytical performance was improved after the corresponding improvement measures were taken. The six sigma model has significant advantages in practical applications involving CSF biochemical analytes and is highly useful for quality assurance and quality improvement. [ABSTRACT FROM AUTHOR]

Background: sST2 has emerged as a potential disease biomarker of cardiac and inflammatory diseases in pediatrics. This study aimed to evaluate the performance of the new Pylon sST2 assay and establish the reference intervals of sST2 in children and adolescence in China. Methods: The experiments on precision, linearity, effects of interferents and sample stability were carried out to evaluate the analytical performances. A total of 240 healthy participants, aged from 2 to 17 years were enrolled. The nonparametric method was used to calculate the age- and sex-specified reference intervals. sST2 levels were measured in children with different diseases to evaluate the assay's diagnostic performance. Results: The repeatability and within-laboratory imprecision CVs of the assay were 6.0% and 7.6% at 19.5 ng/ml, and 3.1% and 5.9% at 289.8 ng/ml, respectively. The method showed linearity between 2.5 and 918.5 ng/ml. It was also noteworthy that the sST2 level was not affected in the presence of hemoglobin (2 mg/ml), triglyceride (30 mg/ml), bilirubin (0.3 mg/ml) and cholesterol (5 mg/ml). sST2 was found stable for 5 days at 4 °C in serum sample. The reference interval was determined as 2.1–21.0 ng/ml in general. No significant variation was observed by sex. However, sST2 increased constantly with age, especially in male. Increased sST2 was found in patients of systemic lupus erythematosus, sepsis, Crohn's diseases, respiratory failure and post cardiac surgery. Conclusions: The Pylon sST2 assay showed good analytical performances. The reference intervals were established in children and adolescence and sST2 showed potential clinical values in several diseases in pediatrics.

ABSTRACT Infection with high-risk human papillomavirus (hrHPV) is well recognized as the main cause of cervical cancer. The recently developed Seegene Allplex HPV28 assay is a novel quantitative PCR (qPCR) assay designed to separately detect and quantify 28 distinct HPV genotypes in a fully automated and user-friendly manner. This study evaluated and compared the performance of this new assay with the performance of the Roche Cobas 4800, the Abbott RealTime high-risk HPV, and the Seegene Anyplex II HPV28 assays. A total of 114 mocked self-samples, i.e., semicervical samples collected by gynecologists using the Viba-Brush, were analyzed with all four HPV assays. Agreement in terms of detecting and genotyping HPV was assessed by the mean of the Cohen’s kappa (κ) coefficient. Results of all four HPV assays agreed in 85.9% of the cases when using the Abbott RealTime manufacturer’s recommended quantification cycle (Cq) cutoff for positivity (

Brhanu Teka,1,2 Muluken Gizaw,2– 4 Ededia Firdawoke,1 Adamu Addissie,3 Tesfamichael Awoke Sisay,3 Carola Schreckenberger,5 Anna Sophie Skof,5 Sarah Thies,5 Adane Mihret,1,6 Eva Johanna Kantelhardt,2,4 Tamrat Abebe,1 Andreas M Kaufmann5 1Department of Microbiology, Immunology and Parasitology, School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia; 2Department of Gynaecology Martin-Luther-University, Halle-Wittenberg, Germany; 3School of Public Health, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia; 4Institute for Medical Epidemiology, Biometrics and Informatics, Martin-Luther-University, Halle-Wittenberg, Germany; 5Department of Gynecology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, 13353, Germany; 6Armauer Hansen Research Institute (AHRI), Addis Ababa, EthiopiaCorrespondence: Andreas M Kaufmann, Tel +49 30 450516499, Fax +4930 450-7 564958, Email Andreas.Kaufmann@charite.dePurpose: High-risk Human Papillomavirus (HPV) is the most important cause of cervical cancer. The highest burden of disease is seen in Low- and Low-Middle-Income Countries (LMIC). Several new HPV screening assays have been developed for high-risk HPV (hr-HPV) testing. We compared the performance and adequacy of three HPV genotyping assays on samples from a population of rural women in south-central Ethiopia.Patients and Methods: One hundred and ten cervical swabs from rural women screened for HPV were assayed. HPV DNA was tested using MPG-Luminex Assay, Anyplex II HPV HR Detection, and EUROArray HPV. MPG-Luminex Assay was used as a reference method to compute the sensitivity and specificity of the two commercial assays in detecting hr-HPV infections.Results: Of the 110 samples, MPG-Luminex Assay found 18.2% positive for the 14 hr-HPV and 7.3% for the probable hr-HPV genotypes. Anyplex™ II HPV HR Detection assay and EUROArray HPV Assay identified 21.82% and 12.7% samples, respectively, for the 14 hr-HPVs and both 7.3% for the probable hr-HPV genotypes (κ=0.734). Among the 14 hr-HPV genotypes, the genotype-specific agreement of the three HPV genotyping assays was moderate or better for HPV16, 31, 35, 39, 52, 56, 66 and 68. The aggregated sensitivity in detecting the 14 hr-HPV infections of Anyplex™ II HPV HR Detection and EUROArray HPV assays was high, 100% and 70%, respectively. The specificities of Anyplex™ II HPV HR Detection and EUROArray HPV were 95.6% and 100%, respectively.Conclusion: The three evaluated assays showed similar analytical performance in the detection of hr-HPV infections and moderate or better concordance in HPV genotyping. This study is part of the ongoing cluster-randomized trial that has been registered in clinicaltrials.gov (NCT03281135) on September 13, 2017.Keywords: analytical performance, HPV PCR test accuracy, HPV test complexity, HPV testing, LMIC

Objective Total analytical error (TAE) and measurement uncertainty (MU) are important approaches to evaluating and improving the quality of measurement procedures. This study evaluates glucose analytical performance (AP) according to TAE and MU and calculates gray zones of glucose critical value limits. Methods Using TAE and MU values, AP was evaluated according to 5 different analytical performance specifications (APS) and the gray zones of critical value limits were calculated. The number of patients in these zones was compared. Results TAE was higher than MU at all 3 levels. The AP for the low glucose level was poor. The number of patients in the gray zones was statistically higher in the TAE groups than in the MU groups (P  < .05). Conclusion TAE and MU values can be used to evaluate the AP of glucose measurement as well as to evaluate the compliance of patient results with decision limits by creating gray zones. [ABSTRACT FROM AUTHOR]

For years, researchers have focused on the determination of metal ions at trace levels in environmental and food samples using analytical methods that employ techniques with low cost acquisition and maintenance and without microwave-assisted acid digestion procedures or aggressive reagents. Therefore, the present study deals with the synthesis and application of a novel, restricted-access poly(protoporphyrin-co-vinyl pyridine) adsorbent to preconcentrate copper in water samples and bovine milk that have only been subjected to pH adjusting (pH 6.0) and filtration using posterior on-line determination by FAAS. Regarding macromolecules, the restricted-access property of the adsorbent was achieved using the hydrophilic compound 2-hydroxyethyl methacrylate (HEMA). This method is based on the preconcentration of Cu2+ ions using a flow-injection system which is buffered with 0.05 mol L−1 of Britton–Robinson (BR) at a pH of 6.0 and has a flow rate of 14.0 mL min−1 through a mini-column packed with 50.0 mg of adsorbent. The elution was carried out using 0.40 mol L−1 of HCl toward the FAAS detector. The developed method provided a preconcentration factor of 44.7-fold, low limits of detection (LOD) (0.90 µg L−1) and quantification (LOQ) (2.90 µg L−1), tolerance to interfering ions (95.0 and 103.0%), and intra-day and inter-day precision assessed as the RSD (percentage of relative standard deviation), which ranged from 3.08 to 4.80%. The restricted-access poly(protoporphyrin-co-vinyl pyridine) adsorbent demonstrated outstanding features to exclude macromolecules, bovine serum albumin (BSA), and humic acid (HA) from an aqueous medium. Lake water and bovine milk samples were analyzed by the proposed preconcentration method with minimal sample pretreatment (which was based mainly on pH adjusting and filtration using an analytical curve with external calibration), yielding recovery values from addition and recovery tests ranging from 91.7 to 101.9%. The developed method shows great advantages over previously published methods, avoiding the time-consuming use of concentrated acids in a microwave-assisted acid digestion procedure. [ABSTRACT FROM AUTHOR]

Many Point-of-Care devices have been released over the past decade. However, data regarding their analytical performances in real-world situations remains scarce. Herein, we aimed to assess the analytical performances of the i-STAT Alinity system. We conducted an analytical performances study with the i-STAT Alinity device using cartridges CG4+ (pH, Pco2, Po2, lactate, bicarbonate and base excess); CHEM8+ (Na, K, Cl, ionized Ca, urea, creatinine, glucose, hematocrit and hemoglobin) and PT/INR (prothrombin time and international normalized ratio). We assessed the imprecision and compared the results to those obtained on existing instruments in the central laboratory. We found that the within-lab coefficients of variation (CV) were very low (<2%) or low (2–5%), except for creatinine and PT (CV = 5.2% and CV = 6.3%, respectively). For almost all the parameters, the results were strongly (R2 = 90–95%) or very strongly (R2 > 95%) correlated with those of the existing laboratory instruments, and the biases were very low (<2%) or low (2–5%). However, correlations of the PT and INR measurements with existing instruments were lower (R2 = 86.0% and 89.7%), and biases in the Po2 (7.9%), creatinine (5.4%) and PT (−6.6%) measurements were higher. The i-STAT Alinity appeared as a convenient device for measurements of numerous parameters. However, clinicians should interpret Po2, creatinine and PT results with caution. [ABSTRACT FROM AUTHOR]

On-site analysis of volatile organic compounds (VOCs) with miniaturized gas chromatography–mass spectrometry (GC–MS) systems is a very rapidly developing field of application. While, on the one hand, major technological advances are improving the availability of these systems on the market, on the other hand, systematic studies to assess the performance of such instruments are still lacking. To fill this gap, we compared three portable GC–MS devices to a state-of-the-art benchtop (stationary) system for analysis of a standard mixture of 18 VOCs. We systematically compared analytical parameters such as the sensitivity and similarity of the signal response pattern and the quality of the obtained mass spectra. We found that the investigated mobile instruments (i) showed different response profiles with a generally lower number of identified analytes. Also, (ii) mass spectral reproducibility (% relative standard deviation (RSD) of the relative abundance of selective fragments) was generally worse in the mobile devices (mean RSD for all targeted fragments ~9.7% vs. ~3.5% in the stationary system). Furthermore, mobile devices (iii) showed a poorer mass spectral similarity to commercial reference library spectra (>20% deviation of fragment ion relative intensity vs. ~10% in the stationary GC–MS), suggesting a less reliable identification of analytes by library search. Indeed, (iv) the performance was better with higher-mass and/or more abundant fragments, which should be considered to improve the results of library searches for substance identification. Finally, (v) the estimation of the signal-to-noise ratio (S/N) in mobile instruments as a measure of sensitivity revealed a significantly lower performance compared to the benchtop lab equipment (with a ratio among medians of ~8 times lower). Overall, our study reveals not only a poor signal-to-noise ratio and poor reproducibility of the data obtained from mobile instruments, but also unfavorable results with respect to a reliable identification of substances when they are applied for complex mixtures of volatiles. [ABSTRACT FROM AUTHOR]