Clinical chemistry and laboratory medicine最新文献

{"title":"Analytical performance evaluation and optimization of serum 25(OH)D LC-MS/MS measurement.","authors":"Weiyan Zhou, Meiliang Gong, Yuanli Mao, Xiaofen Yuan, Yuhang Deng, Qianwen Zhang, Wei Guo, Ling Qiu, Xianzhang Huang, Zheng Cao, Jun Xia, Xuhui She, Yulong Cong, Chuanbao Zhang, Huafen Liu, Wenxiang Chen","doi":"10.1515/cclm-2024-1416","DOIUrl":"https://doi.org/10.1515/cclm-2024-1416","url":null,"abstract":"<p><strong>Objectives: </strong>Measuring serum 25-hydroxyvitamin D is key in clinical labs, but inter-laboratory variations risk diagnostic errors. This study evaluates the performance of current in-house liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods used in top Chinese clinical laboratories and proposes an optimized method for improving serum 25(OH)D measurement accuracy and reliability.</p><p><strong>Methods: </strong>Seven serum pools with different concentrations of 25(OH)D were prepared and sent to 12 participating laboratories for multiple repeat analysis with their current in-house LC-MS/MS methods and then an optimized LC-MS/MS method. Precision was assessed in terms of coefficient of variance (CV), and trueness was assessed in terms of bias referring to the U.S. National Institute of Standards and Technology (NIST) reference measurement procedure (RMP). The analytical performances of the two methods were compared and evaluated.</p><p><strong>Results: </strong>Eighty percent and 90 % of the laboratories achieved the defined performance criteria (CV, <12.5 %; mean bias, <8.3 %) with the optimized method for the measurement of 25(OH)D2 and 25(OH)D3, compared with 43 % and 57 % of the laboratories meeting the criteria with their in-house methods, respectively. Precision and trueness improved after applying the optimized method. Although the optimized method didn't not ensure that all laboratory samples meet the measurement uncertainty (MU) criteria (MU<13.6 %), particularly for low-concentration samples, it significantly reduced the MU compared to the in-house method.</p><p><strong>Conclusions: </strong>Precision, trueness and MU improved after applying the optimized method. Nonetheless, more efforts are needed to ensure the reliability and accuracy of 25(OH)D measurements in clinical laboratories in China.</p>","PeriodicalId":10390,"journal":{"name":"Clinical chemistry and laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143440196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal dynamics in laboratory medicine: cosinor analysis and real-world data (RWD) approaches to population chronobiology.","authors":"Fernando Marques-Garcia, Cristina Martinez-Bravo, Xavier Tejedor-Ganduxe, Ruben Fossion","doi":"10.1515/cclm-2024-1198","DOIUrl":"https://doi.org/10.1515/cclm-2024-1198","url":null,"abstract":"<p><strong>Objectives: </strong>Chronobiology is the science that studies biological rhythms based on direct methods and empirical time series of individual subjects. In laboratory medicine, the factor of time is often underestimated, and no methods currently exist to study biological rhythms in population databases of point-like, real-world data (RWD).</p><p><strong>Methods: </strong>Retrospective databases (24 months, 2022-2023) were extracted for four measurands (sodium, potassium, chloride and leukocytes) from the emergency laboratory. Two different strategies for data grouping were applied: data clouds (with or without outliers) and population-averaged profiles. Cosinor regression analysis was performed on the grouped data to derive circadian parameters. The parameters obtained here were compared to results from the literature, using direct methods and time series.</p><p><strong>Results: </strong>A total of 409,719 data points were analyzed. All measurands exhibited symmetrical data distributions, except for leukocytes. The data clouds did not visually display rhythmicity, but cosinor analysis revealed a significant circadian rhythm. The removal of outliers had minimal impact on the results. In contrast, population-averaged profiles showed visible rhythmicity, which was confirmed by cosinor analysis with a better goodness-of-fit compared to the data clouds.</p><p><strong>Conclusions: </strong>Population-averaged profiles have advantages over data clouds in characterizing circadian rhythms and deriving circadian parameters. Population chronobiology, based on RWD, is presented as an alternative to classical individual chronobiology, based on time series and overcomes the limitations of direct methods. Utilizing RWD provides new insights into the relationship between chronobiology and clinical laboratory practice.</p>","PeriodicalId":10390,"journal":{"name":"Clinical chemistry and laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is it feasible for European laboratories to use SI units in reporting results?","authors":"Martina Zaninotto, Luisa Agnello, Lora Dukic, Tomáš Šálek, Anna Linko-Parvinen, Tejas Kalaria, Pieter Vermeersch","doi":"10.1515/cclm-2025-0113","DOIUrl":"https://doi.org/10.1515/cclm-2025-0113","url":null,"abstract":"<p><p>The ultimate goal of harmonization, crucial to quality in laboratory medicine, is to improve patient outcomes by providing accurate, actionable laboratory information. Patients and healthcare professionals assume that clinical laboratory tests performed by different laboratories at different times on the same type of sample are comparable, and that results can be reliably and consistently interpreted. In this context the reporting units for tests can have a considerable influence on the numeric result. The harmonization of measurement units in laboratory report, leads to the provision of interchangeable and comparable results, thus maximizing the validity of laboratory information, and assuring a more accurate diagnosis and better treatment for the patient. However, although considerable efforts have been made in recent years, the criticisms continue. This opinion paper, prepared jointly by EFLM Committee Harmonization (C-H) and Committee Postanalytical phase (C-POST), describes the \"general pragmatic approach\" proposed in the drafting of guidelines for the harmonization of measurement units in reporting results, in order to ensure they are used as widely as possible.</p>","PeriodicalId":10390,"journal":{"name":"Clinical chemistry and laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Setting analytical performance specification by simulation (Milan model 1b).","authors":"Hui Qi Low, Andrea Rita Horvath, Tze Ping Loh, Mario Plebani, Chun Yee Lim","doi":"10.1515/cclm-2025-0121","DOIUrl":"https://doi.org/10.1515/cclm-2025-0121","url":null,"abstract":"","PeriodicalId":10390,"journal":{"name":"Clinical chemistry and laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143432414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagnostic performance of Mindray CL1200i high sensitivity cardiac troponin I assay compared to Abbott Alinity cardiac troponin I assay for the diagnosis of type 1 and 2 acute myocardial infarction in females and males: MERITnI study.","authors":"Fred S Apple, Kevin G Buda, Barrett P Wagner, Anne Sexter, Yader Sandoval, Stephen W Smith, Kylie Meyer, Alanna Ladd, Kathryn Worrell, Hannah M Brown, Karen M Schulz","doi":"10.1515/cclm-2024-1373","DOIUrl":"https://doi.org/10.1515/cclm-2024-1373","url":null,"abstract":"<p><strong>Objectives: </strong>We examined the 0- and 2-h diagnostic performance of the Mindray high-sensitivity cardiac troponin I (hs-cTnI) assay using two predefined sex-specific 99th percentile upper reference limits (URL) in patients with normal electrocardiograms to aid in the diagnosis of myocardial infarction (MI).</p><p><strong>Methods: </strong>Consecutive emergency department patients undergoing serial high-sensitivity cardiac troponin I (hs-cTnI) testing on clinical indication were studied in the 'Mindray hs-cTnI Assay Analytical and Clinical Evaluation for the Diagnosis and RIsk Assessment of Myocardial InfarctIon' (MERITnI) trial (NCT05853042). Plasma hs-cTnI testing was performed using Mindray CL1200i (investigational) and Abbott Alinity (clinical) assays.</p><p><strong>Results: </strong>In 1,556 patients (60.7 % male, 43.3 % White, 45.8 % Black, 34.8 % chest pain), 2.7 % had type 1 MI, 2.7 % type 2 MI, and 21.5 % non-MI myocardial injury. At 0 h for all MIs (n=86), using package insert URLs and Universal Sample Bank (USB) URLs, sensitivities were 83.7 and 93.0 %. At 0/2 h for all MIs with package insert and USB URLs, sensitivities were higher with serial testing, at 95.3 and 97.7 %. Negative predictive value (NPVs) were excellent and similar for both URLs, ranging from 98 to 100 %. Substantial hs-cTnI concentration differences were observed between sex and injury types. Alinity hs-cTnI diagnostic observations were similar for both package insert and USB URLs.</p><p><strong>Conclusions: </strong>The Mindray CL1200i hs-cTnI assay provides the relevant clinical diagnostic information to enable clinicians to deliver cost-effective care for patients to aid in the diagnosis of MI predicated on 0- and 2-h serial testing based on sex-specific 99th percentiles. Novel observations were observed for findings based on different URLs and for females and MI types.</p>","PeriodicalId":10390,"journal":{"name":"Clinical chemistry and laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143370419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An isotope dilution-liquid chromatography-tandem mass spectrometry-based candidate reference measurement procedure for the quantification of cortisol in human serum and plasma.","authors":"Myriam Ott, Neeraj Singh, Friederike Bauland, Daniel Köppl, Kerstin Kandler, Alexander Gaudl, Andrea Geistanger, Uta Ceglarek, Manfred Rauh, Christian Geletneky, Judith Taibon","doi":"10.1515/cclm-2024-0879","DOIUrl":"https://doi.org/10.1515/cclm-2024-0879","url":null,"abstract":"<p><strong>Objectives: </strong>Accurate measurement of serum cortisol is crucial for the diagnosis and management of adrenal disorders. Thus, we have developed a novel isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC MS/MS)-based candidate reference measurement procedure (RMP) to quantify cortisol in human serum/plasma, offering higher sensitivity and reliability compared to existing RMPs.</p><p><strong>Methods: </strong>Quantitative Nuclear Magnetic Resonance spectroscopic (qNMR) methodology has been utilized to assign the absolute content (g/g) and SI-traceability to the reference materials. A novel two-dimensional heart-cut liquid chromatography (LC) approach was implemented for the LC-MS/MS, combined with a supported liquid extraction (SLE) sample preparation protocol. A multi-day validation experiment assessed precision and accuracy. Reproducibility was assessed by comparing procedure results between two independent laboratories, and measurement uncertainty (MU) was evaluated in compliance with current guidelines.</p><p><strong>Results: </strong>The established RMP exhibited high sensitivity, with a quantification range of 0.800-600 ng/mL (2.21-1,655 nmol/L), exceeding the ranges of existing JCTLM-listed RMPs. Intermediate precision was ≤2.6 %, and repeatability ranged from 0.9 to 1.9 % across all concentration levels. The relative mean bias ranged from -1.3 to 1.4 % for all matrices and concentration levels. Measurement uncertainties (MU) for cortisol in single measurements were ≤2.8 % regardless of the concentration level and sample type. Using the certified International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference panel, the equivalence between the candidate RMP and the Joint Committee on Traceability in Laboratory Medicine (JCTLM) listed RMPs (NRMeth 57 and NRMeth 8) was assessed, revealing excellent agreement.</p><p><strong>Conclusions: </strong>This RMP allows for highly sensitive and reproducible determination of cortisol. The performance of the RMP facilitates the standardization of routine assays and ensures traceability in the measurement of individual patient samples.</p>","PeriodicalId":10390,"journal":{"name":"Clinical chemistry and laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143370395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advancements and challenges in high-sensitivity cardiac troponin assays: diagnostic, pathophysiological, and clinical perspectives.","authors":"Aldo Clerico, Martina Zaninotto, Alberto Aimo, Andrea Padoan, Claudio Passino, Antonio Fortunato, Claudio Galli, Mario Plebani","doi":"10.1515/cclm-2024-1090","DOIUrl":"https://doi.org/10.1515/cclm-2024-1090","url":null,"abstract":"<p><p>Although significant progress has been made in recent years, some important questions remain regarding the analytical performance, pathophysiological interpretation and clinical use of cardiac troponin I (cTnI) and T (cTnT) measurements. Several recent studies have shown that a progressive and continuous increase in circulating levels of cTnI and cTnT below the cut-off value (i.e. the 99th percentile upper reference limit) may play a relevant role in cardiovascular risk assessment both in the general population and in patients with cardiovascular or extra-cardiac disease. International guidelines recommend the use of standardized clinical algorithms based on temporal changes in circulating cTnI and cTnT levels measured by high-sensitivity (hs) methods to detect myocardial injury progressing to acute myocardial infarction. Some recent studies have shown that some point-of-care assays for cTnI with hs performance ensure a faster diagnostic turnaround time and thus significantly reduce the length of stay of patients admitted to emergency departments with chest pain. However, several confounding factors need to be considered in this setting. A novel approach may be the combined assessment of laboratory methods (including hs-cTn assay) and other clinical data, possibly using machine learning methods. In the present document of the Italian Study Group on Cardiac Biomarkers, the authors aimed to discuss these new trends regarding the analytical, pathophysiological and clinical issues related to the measurement of cardiac troponins using hs-cTnI and hs-cTnT methods.</p>","PeriodicalId":10390,"journal":{"name":"Clinical chemistry and laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143363959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simple steps to achieve harmonisation and standardisation of dried blood spot phenylalanine measurements and facilitate consistent management of patients with phenylketonuria.","authors":"Rachel S Carling, Zoe Barclay, Nathan Cantley, Nana Ghansah, Sarah L Hogg, Alistair Horman, Stuart J Moat, Simon Cowen, Chris Hopley, Chloe Deaves, Emily Whyte","doi":"10.1515/cclm-2024-1367","DOIUrl":"https://doi.org/10.1515/cclm-2024-1367","url":null,"abstract":"<p><strong>Objectives: </strong>Management of phenylketonuria (PKU) relies upon life-long monitoring of phenylalanine (Phe) in dried blood spots (DBS), thus comparability of measurements is important. The lack of harmonisation and standardisation between laboratories, combined with the variable quality of patient-collected DBS specimens, are currently preventing this from being achieved. A traceable, matrix-matched Phe certified reference material, common methodology and means to ensure patient collected DBS specimens are of consistent quality would improve comparability between laboratories.</p><p><strong>Methods: </strong>Baseline inter-laboratory (n=15) variation of DBS Phe was determined by triplicate measurement of four DBS materials, on three days. Laboratories prepared and analysed these samples using their routine method of analysis. A sub-set of laboratories (n=5) repeated the process using a common sample preparation and instrument methodology (LC-MS/MS), and three different calibration approaches. Samples prepared on dried blood spot microsampling cards (DBS-MCs) from whole blood, value assigned for Phe concentration by National Measurement Laboratories (NML), were then analysed using the harmonised methodology.</p><p><strong>Results: </strong>Inter-laboratory co-efficient of variation (CV) differed with calibration approach; internal calibration 27.7 %; in-house aqueous calibration 4.7 %; centrally distributed aqueous calibration, 2.1 %. Inter-laboratory CV was reduced from 8.7 to 2.1 % by using common sample preparation and LC-MS/MS methodology. No significant difference was observed between consensus and assigned values for Phe in the four materials (p>0.05).</p><p><strong>Conclusions: </strong>This study demonstrates a simple approach to harmonising and standardising DBS Phe measurements, traceable to value assigned materials. Combined with the introduction of DBS-MCs to ensure specimen quality, clinical laboratories can achieve comparability of patient results over time.</p>","PeriodicalId":10390,"journal":{"name":"Clinical chemistry and laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143078608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inclusion of pyridoxine dependent epilepsy in expanded newborn screening programs by tandem mass spectrometry: set up of first and second tier tests.","authors":"Roberta Damiano, Maria Della Bona, Elena Procopio, Renzo Guerrini, Alessandra Bettiol, Giancarlo la Marca","doi":"10.1515/cclm-2024-1230","DOIUrl":"https://doi.org/10.1515/cclm-2024-1230","url":null,"abstract":"<p><strong>Objectives: </strong>Pyridoxine-dependent epilepsy (PDE) is a rare genetic disorder characterized by intractable neonatal seizures responsive to pyridoxine. Diagnosis relies on quantification of α-aminoadipic semialdehyde, piperideine-6-carboxylate and pipecolic acid in urine or plasma in patients with overt symptoms. We developed and validated simple and rapid first- and second-tier methods for two recently published biomarkers of PDE (2S,6S-/2S,6R-oxopropylpiperidine-2-carboxylic acid (2-OPP) and 6-oxopiperidine-2-carboxylic acid (6-oxoPIP)) in extended newborn screening (NBS) programs from neonatal dried blood spots (DBS).</p><p><strong>Methods: </strong>For the first-line test, DBS specimens were collected from 5,405 newborns who underwent routine NBS and analysed by FIA-MS/MS. For the second-tier test, samples were analysed by LC-MS/MS. The neonatal DBS from two patients with genetically confirmed PDE were also analysed.</p><p><strong>Results: </strong>The reference values for NBS resulted <0.34 μmol/L for 2-OPP and <4.51 μmol/L for 6-oxoPIP. In the second-tier test, limits of detection were 0.07 μmol/L and 0.14 μmol/L, whereas limits of quantification were 0.25 μmol/L and 0.48 μmol/L, respectively, for 2-OPP and for 6-oxoPIP. The tests provided good linearity, reproducibility, accuracy and precision, with acceptable matrix effect and carry-over, according to international validation criteria. The biomarkers in DBS were stable at room temperature, +4 °C and -20 °C for one month. When assessing these biomarkers in two patients with genetically confirmed PDE, the higher sensitivity of 2-OPP as compared to 6-oxoPIP in discriminating PDE emerged.</p><p><strong>Conclusions: </strong>The first-line and second-tier tests developed in this study highlight the potential for including PDE in the NBS panel, early diagnosis and prompt precision treatment initiation.</p>","PeriodicalId":10390,"journal":{"name":"Clinical chemistry and laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143122088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishment of gender- and age-related reference intervals for serum uric acid in adults based on big data from Zhejiang Province in China.","authors":"Dandan Chen, Yunxian Zhou, Lina Fan, Zheng Yang, Dagan Yang","doi":"10.1515/cclm-2024-1288","DOIUrl":"https://doi.org/10.1515/cclm-2024-1288","url":null,"abstract":"<p><strong>Objectives: </strong>This study utilized large-scale health examination data to explore gender- and age-specific reference intervals (RIs) for serum uric acid (UA) using indirect methods and assessed the consistency of different approaches.</p><p><strong>Methods: </strong>UA data were collected from a hospital in Zhejiang Province, China. The test set covered January 2019 to December 2023, with a validation set from January to June 2024. Various methods - EP28 nonparametric (EP28-NP), parametric (EP28-P), TMC, refineR, and Kosmic - were used to establish gender- and age-specific RIs. Continuous age-based RIs were derived using the Generalized Additive Model for Location Scale and Shape (GAMLSS). Validation rates were calculated for each method using the validation set.</p><p><strong>Results: </strong>Using EP28-NP as the benchmark, other methods showed similar UA RIs (bias ratios ≤0.375, except for one group), with Kosmic, refineR, and TMC yielding slightly higher values than EP28-NP and EP28-P. For males, UA RIs varied by age: 19-42 years (256-537 μmol/L), 43-66 years (235-513 μmol/L) and ≥67 years (214-515 μmol/L), with validation rates ranging from 94.05 to 96.50 %. Male continuous RIs declined from ages 20-79 and then gradually increased after age 80. For females, UA RIs were age-dependent: 19-48 years (169-374 μmol/L), 49-74 years (178-405 μmol/L), and ≥75 years (186-470 μmol/L), with validation rates ranging from 92.70 to 96.80 %. Female continuous RIs decreased from ages 20-48, then increased significantly from age 49 onward.</p><p><strong>Conclusions: </strong>Three indirect methods and two EP28 methods demonstrated good consistency in establishing UA RIs. Males had higher RIs than females, and RIs showed a non-linear correlation with age.</p>","PeriodicalId":10390,"journal":{"name":"Clinical chemistry and laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143078607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}