Clinical chemistry and laboratory medicine最新文献

Objectives: Voriconazole is an antifungal agent measured in serum and plasma for therapeutic drug monitoring. This study aimed to develop a robust isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) reference measurement procedure (RMP) to ensure accurate and reliable quantification in compliance with metrological standards.

Methods: A commercially available voriconazole material, traceable to the International System of Units (SI), characterized by quantitative nuclear magnetic resonance spectroscopy (qNMR), served as the primary reference material. Chromatographic separation was achieved using a Raptor Biphenyl column, and isotope-labeled voriconazole was utilized as the internal standard. The candidate RMP was validated for selectivity, matrix effects, linearity, precision, accuracy, sample stability, and measurement uncertainty.

Results: The method's selectivity was successfully demonstrated, with no interfering signals observed at the retention time of voriconazole. Assessment of matrix effects revealed no significant differences in slopes across native serum, analyte-free human serum, and Li-hep plasma, confirming the absence of matrix-derived interferences. Intermediate precision was ≤3.7 %, repeatability was ≤2.3 %, and accuracy showed a mean bias ranging from -0.7 to 2.7 % across all matrices and concentration levels. Relative bias for the lower limit of the measuring interval (LLMI) was 1.7 %, with a coefficient of variation (CV) for intermediate precision of 4.3 %. Expanded measurement uncertainties (k=2) for target value assignment (n=6) ranged from 1.4 to 3.4 %.

Conclusions: This validated ID-LC-MS/MS-based RMP proved to be selective, precise, accurate, and reliable for the quantification of voriconazole in human serum and plasma. The RMP demonstrated high accuracy and precision, along with suitable measurement uncertainty, meeting all relevant requirements for an RMP. These findings support the method's suitability for use in establishing target values and ensuring accuracy in clinical laboratories.

Objectives: 5α-dihydrotestosterone (DHT) is a potent androgen, related to male sexual development and irreversibly synthesized from testosterone via 5α-reductase. Dysfunctions in the 5α-reductase system, locally or globally, can have substantial health impacts; measurement of both DHT levels and the testosterone-DHT ratio are thus important for diagnosis and treatment monitoring. For that reason, an isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC MS/MS)-based candidate reference measurement procedure (RMP) to quantify DHT in human serum/plasma was developed.

Methods: We utilized certified primary reference material for DHT provided by the National Measurement Institute of Australia (NMIA) to calibrate our assay and ensure SI (International System of Units) traceability. To mitigate matrix effects and prevent the co-elution of interferences, two-dimensional heart-cut chromatography was employed for LC-MS/MS, in combination with a solid phase extraction (SPE) sample preparation protocol. Selectivity was determined by spiking the prepared internal standard with possibly interfering substances such as the inactive isomer 5β-DHT and other similar compounds. Comparison of standard line slopes was performed to evaluate matrix effects. Precision and accuracy were assessed via a multi-day validation experiment, and variability components estimated using analysis of variance (ANOVA)-based variance component analysis (VCA). Measurement uncertainty (MU) was evaluated in compliance with current guidelines.

Results: This RMP was suitable for analyzing DHT within the range of 0.0160-2.76 ng/mL (0.0551 nmol/L-9.50 nmol/L), demonstrating selectivity, sensitivity and matrix-independence. Intermediate precision was ≤2.1 %, repeatability was ≤1.6 % across all concentration levels, and relative mean bias ranged from -2.2 to 2.5 %, across matrices and concentrations. Expanded MU for reference value assignment (n=6) was ≤2.8 %, irrespective of concentration or sample type.

Conclusions: This RMP exhibited high analytical performance for DHT quantification and met requirements for measurement uncertainty. Additionally, it enabled differentiation between the 5α-DHT and 5β-DHT isomers. Consequently, this RMP is suitable for routine assay standardization and clinical sample evaluation.

Objectives: Dehydroepiandrosterone (DHEA) is a steroid prohormone and important precursor for estrogen and testosterone biosynthesis. For differential diagnosis of sexual development disorders (e.g., polycystic ovary syndrome, congenital adrenal hyperplasia), accurate measurement of DHEA in clinical testing is essential. To address that need for high-quality, reproducible assays, an isotope dilution-liquid chromatography (LC)-tandem mass spectrometry (MS/MS)-based candidate reference measurement procedure (RMP) for the quantification of DHEA was developed and validated.

Methods: A certified primary reference material from the National Measurement Institute of Australia (NMIA), was used for DHEA assay calibration and to ensure traceability to the International System of Units (SI). Two-dimensional heart-cut chromatography was employed for LC-MS/MS in combination with a solid phase extraction sample preparation protocol, to mitigate matrix effects and prevent interference coelution. Selectivity was evaluated by spiking either the analyte or internal standard with potential interferents, such as dehydroepiandrosterone-sulfate, testosterone, and similar steroid compounds. For the evaluation of matrix effects, standard line slopes of various matrices were compared. Precision and accuracy were assessed via a multi-day validation experiment, and variability components were estimated using variance component analysis. Measurement uncertainty was evaluated in compliance with current guidelines.

Results: This candidate RMP proved suitable for the analysis of DHEA in the measurement range of 0.0800-36.0 ng/mL (0.277-125 nmol/L). Predefined requirements for sensitivity and selectivity were fully met, and independence from matrix effects was demonstrated successfully. Across all tested concentration levels, intermediate precision was ≤1.5 % and repeatability was ≤1.0 %, while the relative mean bias ranged from -1.1 to 0.1 %. Regardless of DHEA concentration or sample type, the expanded measurement uncertainty for reference value assignment (n=6) was ≤1.7 %.

Conclusions: This isotope dilution-LC-MS/MS-based candidate RMP for DHEA in human serum and plasma met pre-defined analytical performance requirements such as precision, specificity and measurement uncertainty, and showed superior selectivity towards several potential interferents tested. It is suitable for application in clinical sample evaluation and routine assay standardization.

The Meeting on Science, Quality and Value of Laboratory Medicine was held on 11 December 2025 in Padua, immediately preceding the 7th European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Conference on the Preanalytical Phase. For organizational reasons, the meeting was structured in two parts, with the first held in December 2025 and the second scheduled for early 2026. The initiative, designed to better steer and promote the activities of all EFLM Committees and Divisions, represents a pivotal step toward overcoming fragmentation and silo-based cultures. By fostering a holistic vision that captures interactions among all EFLM Functional Units, the meeting supported the translation of value-based laboratory medicine principles into real-world practice. This collective opinion paper summarizes the lectures presented at the meeting, providing an overview of ongoing EFLM projects and future developments in value-based laboratory medicine. Importantly, the meeting also generated significant opportunities for collaboration and shared project development, underscoring the transition from isolated activities to a collaborative, value-driven approach.

Objectives: Multiplex arrays offer a high-throughput, cost-effective means for quantifying multiple analytes simultaneously, essential for large-scale biomarker research. However, the shared reactive environment in multiplex assays could lead to variations in results compared to single plex assays, potentially impacting outcomes. This study aimed to explore these differences by examining a "3-plex" cytokine panel vs. single plex assays for tumor necrosis factor-alpha (TNF-α) and interleukin-10 (IL-10).

Methods: Using the R&D Systems Luminex HS Cytokine Panel A, 72 serum samples were tested across several batches, including three "3-plex" and two "1-plex" batches each for IL-10 and TNF-α. We evaluated differences in cytokine values using paired t-tests, comparing within 1-plex, between 3-plex, and between 1-plex and 3-plex assays. Bland-Altman plots visually assessed absolute and percentage differences.

Results: IL-10 values were similar between 1-plex and 3-plex assays, showing an average difference of 4.2 fmol/L (10.7 %), which was less than the within plex differences. Conversely, TNF-α showed a 16.7 % difference in the between plex comparison, compared to a 12 % difference in the within plex comparisons. Statistically significant differences emerged mainly for IL-10 across all comparisons. Bland-Altman analyses indicated pronounced variability at low analyte concentrations.

Conclusions: While the multiplex assays demonstrated variation at low analyte levels, especially for IL-10, such differences might not substantially affect comparability when mixed with single plex assays, particularly in datasets dominated by low concentrations.

Laboratory medicine lies at the core of modern healthcare, enabling timely diagnosis, effective patient monitoring, and increasingly personalized therapeutic strategies. Over the past decades, automation has profoundly reshaped the role of clinical laboratories, substantially enhancing their contribution to clinical outcomes, operational efficiency, and the overall sustainability of healthcare systems. More recently, laboratory automation has emerged as a cornerstone of value-based laboratory medicine, representing not merely a technological upgrade but a strategic transformation of laboratory practice aimed at delivering measurable value to patients and healthcare stakeholders. Although automation has long been established in clinical chemistry and immunoassays, its scope is now expanding to molecular diagnostics and mass spectrometry - two disciplines that are central to precision medicine. Looking ahead, the convergence of automation, digitalization, and artificial intelligence is driving the emergence of hyperautomation in laboratory medicine. Within this paradigm, laboratories evolve from isolated testing units into integrated diagnostic hubs, in which results from multiple laboratory disciplines are harmonized and contextualized to effectively support clinical decision-making.

Objectives: Severe fever with thrombocytopenia syndrome virus (SFTSV) is a tick-borne pathogen that can cause a fatality rate as high as 12-50 %, posing a significant threat to public health. SFTSV is prevalent in mountainous and hilly regions with relatively poor medical conditions. Therefore, there is an urgent need to develop a new convenient, rapid and sensitive method for SFTSV detection in low-resource environments.

Methods: We developed a one-pot and visualized method for SFTSV detection using loop-mediated isothermal amplification assisted by CRISPR/Cas12b with G478A/K396A double mutations (LAC12b-2M). The specificity, sensitivity, accuracy and limit of detection (LOD) of LAC12b-2M were evaluated using clinical reverse transcription-quantitative PCR (RT-qPCR) as the reference method, with gradient dilutions of strong positive SFTSV RNA samples and 215 clinical serum samples from two cohorts.

Results: LAC12b-2M is sensitive to detect SFTSV with a LOD of 1 copy/μL at 61 °C within 30 min. Compared to clinical RT-qPCR, LAC12b-2M demonstrated a sensitivity of 98.8 % (82/83), a specificity of 100.0 % (96/96), and an accuracy of 99.4 % (178/179) in cohort 1 (n=179), and an accuracy of 100.0 % in cohort 2 (n=36).

Conclusions: Our LAC12b-2M method holds promise for point-of-care SFTSV testing in different healthcare settings, particularly in low-resource region where SFTSV is prevalent.

Background: Method-comparison studies in laboratory medicine are routinely interpreted using regression-based or Bland-Altman analyses. Although useful descriptively, these statistical procedures are frequently misapplied to infer "agreement", "equivalence", or "interchangeability". Such interpretations overlook essential metrological conditions - including the definition of the measurand, the traceability chain, and measurement uncertainty - leading to misconceptions with potential clinical consequences.

Content: This Opinion Paper clarifies the distinct meanings of four metrological concepts that are often treated as synonyms: comparability, compatibility, equivalence, and interchangeability. We explain why numerical similarity or statistical association does not establish metrological relatedness, and outline the specific requirements for each concept. Comparability requires a shared measurand and calibration hierarchy; compatibility requires differences smaller than the combined uncertainty; equivalence requires clinically irrelevant residual differences; and interchangeability requires stability of clinical decisions when substituting one measuring system for another. We also discuss familiar sources of misinterpretation, including ambiguous definitions of the measurand, incomplete traceability chains, and uncritical reliance on regression- or bias-based summaries.

Summary and outlook: Distinguishing among comparability, compatibility, equivalence, and interchangeability is essential for the metrological interpretation of method-comparison studies and for ensuring safe analytical and clinical decision-making. Integrating these concepts explicitly into study design, harmonisation strategies, and reporting practice will strengthen traceability implementation, prevent erroneous claims of "agreement", and support more reliable patient care.