UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: The newly developed mobile phase buffers demonstrated good analytical performance and were suitable for clinical HbA1c assays on an ARKRAY HA-8160 Analyzer.

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.

OBJECTIVE: 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.
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 %.
RESULTS: 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 %.
CONCLUSIONS: 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.

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.

OBJECTIVE: 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.
CONCLUSIONS: 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.

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.

UNASSIGNED: Early and accurate diagnosis is crucial for preventing the spread of SARS-CoV-2 infection. The rapid antigen test was developed for testing infection, and it was necessary to assess its performance before widespread use in Tunisia.
UNASSIGNED: To evaluate the effectiveness of a rapid antigen test for the detection of SARS-CoV-2 in nasopharyngeal swabs in Tunisia.
UNASSIGNED: Nasopharyngeal samples were taken from COVID-19 suspected cases between October and December 2020 and tested using the Standard Q COVID-19 Ag test (SD-Biosensor, Republic of Korea) and real-time reverse transcription polymerase chain reaction (RT‑PCR).
UNASSIGNED: Overall, 4539 patients were tested. Of the total study population (N = 4539), 82.5% of positive samples remained positive with the rapid antigen test, while 20.2% (470/2321) of samples that were negative with rapid antigen test were confirmed positive with RT-PCR, giving a negative predictive value of 79.8% for the rapid antigen test. The sensitivity and negative predictive value of the rapid antigen test were 70.2% and 65.8%, respectively. These results improved to 96.4% and 92.8%, respectively, when considering the cycle threshold value by RT-PCR below 25.
UNASSIGNED: Although the rapid antigen test was less sensitive than RT-PCR, its ability to rapidly detect individuals with high viral loads makes it suitable for use during an epidemic.
موثوقية اختبار المستضدات السريع لتشخيص فيروس كورونا-سارس-2.
امال شطورو. سبا القرقوري. عبد النور النصري. عواطف تقتق. فهمي السماوي. الفة شقرون. نور الدين الرقيق. عدنان الحمامي. لمياء الفقي بالراجح. هالة الكراي.
UNASSIGNED: التشخيص المبكر والدقيق أمر بالغ الأهمية لمنع انتشار عدوى فيروس كورونا-سارس-2. صمم \"اختبار المستضدات السريع\" لاختبار العدوى، وكان من الضروري تقييم أدائه قبل استخدامه على نطاق واسع في تونس.
UNASSIGNED: هدفت هذه الدراسة الى تقييم فعالية \"الاختبار السريع للمستضدات\" للكشف عن فيروس كورونا-سارس-2 في المسحات الأنفية البلعومية في تونس.
UNASSIGNED: أُخذت عينات أنفية بلعومية من الحالات المشتبه في إصابتها بكوفيد-19 في الفترة بين أكتوبر / تشرين الأول وديسمبر / كانون الأول 2020، واختُبرت باستخدام اختبار Q القياسي للكشف عن المستضدات الحيوية لكوفيد-19 (SD-BIOSENSOR، جمهورية كوريا) و\"التناسخ العكسي لتفاعل البوليميراز المتسلسل\" في الوقت الحقيقي (RT-PCR).
UNASSIGNED: بوجه عام، خضع 4539 مريضًا للاختبار. وتبيََّّن أن 82.51٪ من إجمالي العينات الإيجابية التي اختُبرت باستخدام \"اختبار المستضدات السريع\" أو \"التناسخ العكسي لتفاعل البوليميراز المتسلسل\" إيجابيًّا مع \"اختبار المستضدات السريع\". وبلغت الحساسية والقيمة التنبؤية السلبية \"لاختبار المستضدات السريع\" 70.2٪ و65.8٪ على التوالي. وتحسنت هذه النتائج إلى 96.4٪ و92.8٪ ، على التوالي، عند النظر في قيمة عتبة الدورة باستخدام \"التناسخ العكسي لتفاعل البوليميراز المتسلسل\" دون 25.
UNASSIGNED: على الرغم من أن \"اختبار المستضدات السريع\" كان أقل حساسية من \"التناسخ العكسي لتفاعل البوليميراز المتسلسل\"، فإن قدرته على الكشف السريع عن الأفراد الذين يحملون كميات فيروسية عالية تجعله مناسبًا للاستخدام في أثناء الوباء.
Fiabilité du test de détection antigénique rapide pour le diagnostic du SARS-CoV-2 en Tunisie.
UNASSIGNED: Un diagnostic précoce et exact est essentiel pour prévenir la propagation de l\'infection à SARS-CoV-2. Le test de détection antigénique rapide a été mis au point pour dépister l\'infection, et il était nécessaire d\'évaluer ses performances avant de l\'utiliser à grande échelle en Tunisie.
UNASSIGNED: Évaluer l\'efficacité d\'un test antigénique rapide pour la détection du SARS-CoV-2 dans les prélèvements nasopharyngés en Tunisie.
UNASSIGNED: Des échantillons nasopharyngés ont été prélevés chez des cas suspectés de COVID-19 entre octobre et décembre 2020, et testés à l\'aide du test standard Q de détection antigénique de la COVID-19 (SD-Biosensor, République de Corée) et de la réaction en chaîne par polymérase en temps réel après transcription inverse (RT-PCR).
UNASSIGNED: Au total, 4539 patients ont été dépistés. Sur l\'ensemble de la population étudiée (N = 4539), 82,5 % des échantillons positifs sont restés positifs avec le test antigénique rapide, tandis que 20,2 % (470/2321) des échantillons négatifs avec ce test rapide se sont révélés positifs lors de la RT-PCR, donnant ainsi une valeur prédictive négative de 79,8 %. La sensibilité et la valeur prédictive négative de ce test étaient de 70,2 % et 65,8 %, respectivement. Ces résultats sont passés à 96,4 % et 92,8 %, respectivement, lorsque la valeur seuil du cycle de la RT-PCR est inférieure à 25.
UNASSIGNED: Bien que le test de détection antigénique rapide soit moins sensible que la RT-PCR, sa capacité à détecter rapidement les individus ayant une charge virale élevée permet de l\'utiliser pendant une épidémie.

OBJECTIVE: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.

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.

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