Enhanced Diagnostic Accuracy in Hepatitis B: Human vs. Sheep-Derived Antibodies in HBsAg Confirmatory Testing.

Background: HBsAg confirmatory testing is crucial for accurately diagnosing HBV infection and avoiding false positives. We compared the performance of human-derived and sheep-derived anti-HBs reagents in the Elecsys HBsAg confirmatory test (Roche Diagnostics, Germany).

Methods: Samples with a HBsAg COI of 0.

Quantitative Evaluation of the Real-World Harmonization Status of Laboratory Test Items Using External Quality Assessment Data.

Background: In recent decades, the analytical quality of clinical laboratory results has substantially increased because of collaborative efforts. To effectively utilize laboratory results in applications, such as machine learning through big data, understanding the level of harmonization for each test would be beneficial. We aimed to develop a quantitative harmonization index that reflects the harmonization status of real-world laboratory tests.

Impact of Academia-Government Collaboration on Laboratory Medicine Standardization in South Korea: analysis of eight years creatinine proficiency testing experience.

Objectives: To evaluate the performance of the Academia-Government Collaboration for Laboratory Medicine Standardization in Korea (KR-STDZN) based on data from KR-STDZN proficiency testing (KR-STDZN-PT) for creatinine over eight years (2015-2022).

Methods: We used KR-STDZN-PT data of creatinine tests from 2015 to 2022. Acceptance of the participating institutions' test results was assessed by calculating the acceptance performance as absolute bias (absBias%), total coefficient of variance (tCV%), and total error (TE%) for each sample using six measurements from each institution and true values of each reference material.

Evaluation of Group Genetic Counseling Sessions via a Metaverse-based Application.

Background: Group genetic counseling has been implemented to meet growing demand. A metaverse platform, in which a society is built and activities are carried out in the virtual world, has not yet been implemented in group genetic counseling. We investigated whether a metaverse platform could be an alternative service-delivery model for group genetic counseling.

Interpreting changes in consecutive laboratory results: clinician's perspectives on clinically significant change.

Background: Clinical laboratory tests are inevitably affected by various factors. Therefore, when comparing consecutive test results, it is crucial to consider the inherent uncertainty of the test. Clinical laboratories use reference change value (RCV) to determine a significant change between 2 results.

Evaluation of Vancomycin Area Under the Concentration-Time Curve Predictive Performance Using Bayesian Modeling Software With and Without Peak Concentration: An Academic Hospital Experience for Adult Patients Without Renal Impairment.

Background: The revised U.S. consensus guidelines on vancomycin therapeutic drug monitoring (TDM) recommend obtaining trough and peak samples to estimate the area under the concentration-time curve (AUC) using the Bayesian approach; however, the benefit of such two-point measurements has not been demonstrated in a clinical setting.

A New Strategy for Evaluating the Quality of Laboratory Results for Big Data Research: Using External Quality Assessment Survey Data (2010-2020).

Background: To ensure valid results of big data research in the medical field, the input laboratory results need to be of high quality. We aimed to establish a strategy for evaluating the quality of laboratory results suitable for big data research.

Methods: We used Korean Association of External Quality Assessment Service (KEQAS) data to retrospectively review multicenter data.

Clinical Relevance of a Vancomycin 24 h Area under the Concentration-Time Curve Values Using Different Renal Function Equations in Bayesian Dosing Software.

With the updated 2020 vancomycin therapeutic drug monitoring (TDM) guidelines suggesting a ratio of area under the curve over 24 h to a minimum inhibitory concentration (AUC24/MIC) as a target from the Infectious Diseases Society of America, an accurate estimation of AUC24 has become more critical. We aim to compare the AUC24 using Bayesian dosing software according to various estimated glomerular filtration rate (eGFR) equations in order to analyze the clinical impact of eGFR in vancomycin TDM. We reviewed the TDM dataset of 214 adult patients and analyzed the AUC24 values from various renal function equations, including the Cockcroft-Gault (C-G), the modification of diet in renal disease (MDRD), the chronic kidney disease epidemiology collaboration (CKD-EPI), and the revised Lund−Malmö.

Accuracy of the New Creatinine-based Equations for Estimating Glomerular Filtration Rate in Koreans.

Background: New creatinine-based estimated glomerular filtration rate (eGFR) equations, including the 2021 Chronic Kidney Disease Epidemiology Collaboration (2021 CKD-EPI) and European Kidney Function Consortium (EKFC) equations, have been introduced recently. We assessed the performance of the 2021 CKD-EPI and EKFC equations in the Korean population.

Methods: We analyzed 1,654 Korean patients aged ≥18 years who underwent chromium-51-ethylenediamine tetraacetic acid GFR measurements (mGFR).

Performance of the New RAPIDPoint 500e Blood Gas Analyzer and its Comparison with Central Laboratory Biochemistry Analyzer.

Background: Blood gas analyzers are commonly used in point of care settings in hospitals to assess and monitor critically ill patients. The blood gas analyzer, RAPIDPoint 500e (Siemens Healthcare, UK), has been newly introduced. Here, we evaluated the performance of RAPIDPoint 500e for the determination of pH, partial carbon dioxide pressure, partial oxygen pressure, sodium (Na+), potassium (K+), chloride (Cl-), ionized calcium, glucose, and lactate.

Comparison between polynomial regression and weighted least squares regression analysis for verification of analytical measurement range.

Objectives: Recently, the linearity evaluation protocol by the Clinical & Laboratory Standards Institute (CLSI) has been revised from EP6-A to EP6-ED2, with the statistical method of interpreting linearity evaluation data being changed from polynomial regression to weighted least squares linear regression (WLS). We analyzed and compared the analytical measurement range (AMR) verification results according to the present and prior linearity evaluation guidelines.

Methods: The verification of AMR of clinical chemistry tests was performed using five samples with two replicates in three different laboratories.

Evaluation of Serum Beta-2-Microglobulin Assay on Beckman Coulter Chemistry Analyzer.

Background: Beta-2 microglobulin (β2M) has various clinical usages and is an important prognostic marker for multiple myeloma. Although there are concerns of harmonization between assays, performance evaluation and method comparison reports are rare. Here, we evaluated the performance of Beckman-Coulter β2M assay.

Serum biomarkers for bisphosphonate-related osteonecrosis of the jaw: a prospective clinical study.

Unlabelled: In this prospective study, serum levels of 12 possible biomarkers were compared between osteonecrosis of the jaw (ONJ) and control groups, before and after dentoalveolar surgery. The results suggest that patients with abnormal serum levels of specific biomarkers should be monitored closely for the prevention and early diagnosis of ONJ.

Introduction: Bisphosphonate-related osteonecrosis of the jaw (ONJ) is an adverse effect of long-term bisphosphonate therapy.

Recent Trends in Creatinine Assays in Korea: Long-Term Accuracy-Based Proficiency Testing Survey Data by the Korean Association of External Quality Assessment Service (2011-2019).

Background: Accurate serum creatinine (Cr) concentration measurement is essential for evaluating kidney function. In 2011, the Korean Association of External Quality Assessment Service (KEQAS) launched an accuracy-based Cr proficiency testing (ABCr PT) survey. We analyzed long-term data of the KEQAS ABCr PT survey collected between 2011 and 2019 to assess recent trends in Cr assays in Korea.

False-positive flag of WBC and change of mean platelet volume (MPV) caused by K3-EDTA on the DxH 900 hematology analyzer.

During the evaluation of the DxH 900 hematology analyzer (Beckman Coulter, Miami, FL), we noted that some patient samples produced a false positive white blood cell (WBC) flag, neutrophil blasts (NE-blast), despite the absence of abnormal cells. We investigated whether storage time or anticoagulants such as K2- or K3-ethylenediaminetetraacetic acid (EDTA) would affect complete blood count (CBC) tests on the DxH 900. Sixty-four whole blood samples were collected in K3-EDTA tubes, and 44 were simultaneously drawn in K2-EDTA tubes.

Performance Evaluation of the Third-Generation Elecsys FT4 III Assay for Free Thyroxine.

Background: Roche Diagnostics has recently released the Elecsys FT4 III, Roche's third-generation reagent for free thyroxine. We aim to evaluate the analytical performance of the Elecsys FT4 III.

Methods: The precision and linearity of the Elecsys FT4 III assay were evaluated according to Clinical and Laboratory Standards Institute procedures.

Performance Evaluation of the Elecsys Growth Hormone and Insulin-Like Growth Factor 1 Assay.

Background: Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) are important biomarkers for diagnosis and follow-up of growth-related disorders. Performance of Elecsys hGH and Elecsys IGF-1 (Roche Diagnostics) was evaluated.

Methods: The performance of the Elecsys hGH and Elecsys IGF-1 assays on a Roche Cobas e 801 modular analyzer were evaluated.

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.

Proposal of Efficient Workflows for Confirmatory Neutralization Test for Initial Hepatitis B Surface Antigen Positive Samples.

Background: Since more sensitive immunoassays have been introduced, false positive Hepatitis B surface antigen (HBsAg) results are increasing. This study was carried out to propose a process to reduce the burden of the laboratory while increasing positive predictive value in HBsAg.

Methods: Samples with Elecsys HBsAg II (Roche Diagnostics, Germany) between cutoff index (COI) 0.