Martin Frank Strand, Helle Borgstrøm Hager, Per Morten Fredriksen, Morten Lindberg
{"title":"Reference intervals for holotranscobalamin and total vitamin B12 in 6-12-year-old children in Norway: the Health Oriented Pedagogical Project (HOPP).","authors":"Martin Frank Strand, Helle Borgstrøm Hager, Per Morten Fredriksen, Morten Lindberg","doi":"10.1080/00365513.2025.2475454","DOIUrl":"10.1080/00365513.2025.2475454","url":null,"abstract":"<p><p>Vitamin B12 (B12) is essential for DNA synthesis in all cells and for the development and maintenance of a healthy nervous system. B12 is transported in the circulation bound to two carrier proteins, haptocorrin and transcobalamin, measured as the biomarkers total B12 and holotranscobalamin (holoTC). The latter measures the fraction of cobalamin available for tissue uptake and is considered to have a better sensitivity and specificity for diagnosing vitamin deficiency. The concentration of both carrier proteins depends on age, but data on paediatric reference values for holoTC are still sparse. Blood samples were obtained from 1320 healthy school children, mainly Caucasians (age 6-12 years old) in three different municipalities in Norway. The holoTC and total B12 levels were determined by chemiluminescent microparticle immunoassay on the Architect 2000 analyser. Age specific paediatric reference intervals (RIs) were estimated by calculating the 2.5 and 97.5 percentiles by the nonparametric method with corresponding 90% confidence intervals, according to the Clinical and Laboratory Standards Institute C28-A3C guidelines. The 95% RIs for total B12 were 295-1066 pmol/L for children 6-8 years old, and 249-879 pmol/L for children 9-12 years old. Reference intervals for holoTC were ≥56 pmol/L for children 6-8 years old, and ≥37 pmol/L for children 9-12 years old. Age specific RIs will aid clinicians in interpretation of cobalamin results in children aged 6-12 years old.</p>","PeriodicalId":21474,"journal":{"name":"Scandinavian Journal of Clinical & Laboratory Investigation","volume":" ","pages":"138-142"},"PeriodicalIF":1.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143630890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jaime I Sainz de Medrano, Javier Laguna, Judit Julian, Xavier Filella, Aleix Fabregat, María Luquin, Harol H Hurtado, Alba García Humanes, Manuel Morales-Ruiz, Esther Fernández-Galán
{"title":"Comparison of two automated immunoassays for quantifying ProGRP, SCC and HE4 in serum: impact on diagnostic accuracy.","authors":"Jaime I Sainz de Medrano, Javier Laguna, Judit Julian, Xavier Filella, Aleix Fabregat, María Luquin, Harol H Hurtado, Alba García Humanes, Manuel Morales-Ruiz, Esther Fernández-Galán","doi":"10.1080/00365513.2025.2466008","DOIUrl":"10.1080/00365513.2025.2466008","url":null,"abstract":"<p><p>ProGRP (Progastrin-releasing peptide), SCC (Squamous Cell Carcinoma Antigen), and HE4 (Human epididymis protein 4) are serum tumor markers (STMs) frequently used in clinical practice, particularly for detection and monitoring of ovarian and lung neoplasms. In clinical laboratories, their quantification is commonly performed using automated immunoassays. Nevertheless, variations in results obtained by different immunoassays can impact diagnostic accuracy and effectiveness of patient monitoring. Our aim is to assess differences in STMs concentrations between two automated immunoassays: the Elecsys (Roche) and the Architect (Abbott), which are integrated into the Cobas e402 and Architect i2000SR systems respectively. We included 401 serum samples from patients with different clinical conditions: patients with cancer (<i>n</i> = 170), benign diseases (<i>n</i> = 100) and a control group (<i>n</i> = 131). ProGRP, SCC, and HE4 concentrations were quantified in parallel by both analyzers. To evaluate the clinical impact of changing these methodologies, overall concordance, the kappa index and ROC (Receiver Operating Characteristic) curves were calculated. While some discrepancies were noted in specific cases, overall, we obtained a good correlation for three STMs, with a Pearson coefficient for proGRP (<i>r</i> = 0.99), SCC (<i>r</i> = 0.95) and HE4 (<i>r</i> = 0.973). We also obtained a similar performance in the differential diagnosis of cancer, according to the results of the ROC analyses for Cobas and Archictect assays respectively: proGRP (AUC = 0.92; 0.91), SCC (AUC = 0.90; 0.92) and HE4 (AUC = 0.92; 0.93).</p>","PeriodicalId":21474,"journal":{"name":"Scandinavian Journal of Clinical & Laboratory Investigation","volume":" ","pages":"116-124"},"PeriodicalIF":1.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143425657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arne Åsberg, Marius Berg, Gunhild Garmo Hov, Ingrid Alsos Lian, Lena Løfblad, Gustav Mikkelsen
{"title":"The HUNT study: long-term within-subject variation of thyroid stimulating hormone (TSH).","authors":"Arne Åsberg, Marius Berg, Gunhild Garmo Hov, Ingrid Alsos Lian, Lena Løfblad, Gustav Mikkelsen","doi":"10.1080/00365513.2025.2475473","DOIUrl":"10.1080/00365513.2025.2475473","url":null,"abstract":"<p><p>Data on the long-term within-subject biological variation (CV<sub>I</sub>) of serum thyroid stimulating hormone (S-TSH) are scarce. In the EFLM Biological Variation Database, the longest observation period was one year. We estimated a coefficient of variation that included analytical variation (CV<sub>I+A</sub>) using data from 16,976 individuals in the Trøndelag Health Study (HUNT), where S-TSH was measured on two occasions with an average interval of 10.6 (range 9.3-12.3) years. These individuals reported their health to be 'good' or 'very good' on both occasions and were not registered with any diagnoses or use of medications (according to Norwegian Prescribed Drug Registry) related to the thyroid. We used the software refineR to identify an assumed nonpathological subpopulation in the distribution of distances from each observation to the center of the bivariate distribution of the two S-TSH-values. From this subpopulation, individuals with a distance ≤ the 95 percentile in the distribution of distances were selected for estimation of CV<sub>I+A</sub>. The difference in percent of the mean (DPM) was calculated for each individual, and CV<sub>I+A</sub> as the standard deviation in the distribution of DPMs divided by 2<sup>0.5</sup>. This method was robust against systematic bias between the two measurements. CV<sub>I+A</sub> was 21<b>-</b>23% for different groups of age and sex. Accounting for CV<sub>A</sub> would imply a CV<sub>I</sub> 0.1-0.8% less than CV<sub>I+A</sub>. Our estimates are well within the 12-29.3% range of CV<sub>I</sub> reported from the seven studies in the meta-analysis of the EFLM Biological Variation Database.</p>","PeriodicalId":21474,"journal":{"name":"Scandinavian Journal of Clinical & Laboratory Investigation","volume":" ","pages":"143-147"},"PeriodicalIF":1.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Clara Erixon, Louise Thelaus, Emilia Johannesson, Johan Nilsson, Karl Teurneau-Hermansson, Adam Linder, Sigurdur Ragnarsson, Niklas Sterner, Igor Zindovic, Alain Dardashti
{"title":"The predictive value of postoperative soluble urokinase plasminogen activator receptor concentration for postoperative complications following valvular surgery.","authors":"Clara Erixon, Louise Thelaus, Emilia Johannesson, Johan Nilsson, Karl Teurneau-Hermansson, Adam Linder, Sigurdur Ragnarsson, Niklas Sterner, Igor Zindovic, Alain Dardashti","doi":"10.1080/00365513.2025.2479042","DOIUrl":"10.1080/00365513.2025.2479042","url":null,"abstract":"<p><p>Soluble urokinase plasminogen activator receptor (suPAR) is an inflammatory marker that has been shown to predict poorer outcomes in cardiovascular disease and after cardiac surgery. The relationship between suPAR concentrations and postoperative complications after valvular surgery, however, remains unclear. This study aims to evaluate the predictive value of suPAR concentrations for infection, acute kidney injury (AKI) and prolonged mechanical ventilation after valvular surgery. This prospective, observational, single-centre study included 414 patients who underwent valvular cardiac surgery at Skåne University Hospital between 1 February 2020 and 22 September 2021. Early postoperative suPAR levels were measured, and multivariable logistic regression was used to identify significant risk factors for postoperative infection, AKI and prolonged mechanical ventilation. Left ventricular ejection fraction (LVEF) 30-50% (OR 3.57 [1.29-9.86], <i>p</i> = 0.014) and suPAR concentration (OR 1.41 [1.56-1.71], <i>p</i> <0.001) were found to be predictive risk factors for developing postoperative infection. Additionally, suPAR concentration (OR 1.23 [1.05-1.43], <i>p</i> = 0.008), cardiopulmonary bypass (CPB) time (OR 1.01 [1.00-1.02], <i>p</i> = 0.004) and age (OR 1.04 [1.01-1.08], <i>p</i> = 0.007) were found to be predictive risk factors for postoperative AKI. However, suPAR concentration did not predict prolonged mechanical ventilation. Plasma suPAR levels after cardiac valve surgery were found to be predictive of postoperative AKI and infection. Our results indicate that early postoperative suPAR measurements may be a valuable tool for identifying patients at higher risk for developing postoperative complications.</p>","PeriodicalId":21474,"journal":{"name":"Scandinavian Journal of Clinical & Laboratory Investigation","volume":" ","pages":"160-167"},"PeriodicalIF":1.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143633624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Claudio Ilardo, Marion Baumelou, Nathalia Arias Rojas, Rachida El Youssfi, Margaux Dirat
{"title":"Monitoring CD3+, CD4+ and CD8+ T lymphocytes count after prolonged blood storage.","authors":"Claudio Ilardo, Marion Baumelou, Nathalia Arias Rojas, Rachida El Youssfi, Margaux Dirat","doi":"10.1080/00365513.2025.2477630","DOIUrl":"10.1080/00365513.2025.2477630","url":null,"abstract":"<p><strong>Introduction: </strong>Monitoring CD3+, CD4+ and CD8+ T lymphocytes count is used in patients with known HIV infection, to determine efficacy of antiretroviral medication. Sometimes, due to the long distance, more time is needed for the sample to reach a more equipped laboratory. The aim of our study was to evaluate the impact of prolonged pre-analytical storage of blood at temperature, 96 h at room temperature, on the quality of results for the three parameters.</p><p><strong>Methods: </strong>The analysis of 60 EDTA-anticoagulated blood samples, stored at room temperature (15-25 °C) after sampling, was conducted after 24 h and 96 h, respectively. The BD FACSLyric<sup>™</sup> system was used to identify and enumerate CD3+, CD4+, and CD8+ T lymphocytes.</p><p><strong>Results: </strong>Following a 96-hour period, no notable discrepancies were observed in the data for CD3+, CD4+, and CD8+ T lymphocytes. Passing-Bablok regression analysis showed no significant difference in y-intercept and slope. The Pearson correlation coefficient (r) demonstrated a significant and strong correlation with rho values of 0.994, 0.992, and 0.996, respectively. The analytical agreements demonstrated that all results fell within the total allowable margin of total error.</p><p><strong>Conclusion: </strong>The results of this study demonstrated that diagnostic samples, monitored for CD3+, CD4+ and CD8+ T lymphocytes, could be stored for up to 96 h without compromising the quality of the results.</p>","PeriodicalId":21474,"journal":{"name":"Scandinavian Journal of Clinical & Laboratory Investigation","volume":" ","pages":"172-174"},"PeriodicalIF":1.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"CgA<sub>100</sub> - eGFR-adjusted serum chromogranin A.","authors":"Arne Åsberg, Gustav Mikkelsen, Lena Løfblad","doi":"10.1080/00365513.2025.2466058","DOIUrl":"10.1080/00365513.2025.2466058","url":null,"abstract":"<p><p>The concentration of chromogranin A in serum (s-CgA) is a general marker of neuroendocrine neoplasms. Unfortunately, s-CgA is increased in several other clinical conditions, including renal failure. The physician who assesses s-CgA values must consider the patients' renal function. How this should be done is not clear. We developed an adjustment formula from the association between median s-CgA and the estimated glomerular filtration rate (eGFR) in 2708 patients where s-CgA was measured by the CgA II KRYPTOR method. We used multivariable fractional polynomial quantile regression with the model ln(s-CgA) = c<sub>0</sub> + c<sub>1</sub> × sex + c<sub>2</sub> × age + c<sub>3</sub> × eGFR, thus accounting for sex and age. The final adjustment formula could be simplified to s-CgA<sub>100</sub> = (eGFR / 100) × s-CgA, where s-CgA<sub>100</sub> is an indication of what s-CgA would be if eGFR in the same patient was 100 mL/minute/1.73 m<sup>2</sup>. In patients with eGFR > 100 mL/minute/1.73 m<sup>2</sup> no adjustment was done. We tested the formula on another patient population (<i>n</i> = 1563), where s-CgA was measured by a RIA method. S-CgA<sub>100</sub> proved to be independent of eGFR in that population. The clinical validity of s-CgA<sub>100</sub> must await further investigations.</p>","PeriodicalId":21474,"journal":{"name":"Scandinavian Journal of Clinical & Laboratory Investigation","volume":" ","pages":"133-137"},"PeriodicalIF":1.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143483639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Three new tools to diagnose B12 deficiency: eGFR-adjusted methylmalonic acid (MMA<sub>100</sub>), a bivariate reference area for MMA<sub>100</sub> and cobalamin, and a cobalamin deficiency index.","authors":"Arne Åsberg, Gustav Mikkelsen, Ingrid Alsos Lian","doi":"10.1080/00365513.2025.2463084","DOIUrl":"10.1080/00365513.2025.2463084","url":null,"abstract":"<p><p>Vitamin B12 (s-cobalamin) and methylmalonic acid (s-MMA) are often interpreted together to diagnose cobalamin deficiency, in context with patient symptomatology, which is many cases is unspecific. Today, clinicians assess test results in relation to the univariate reference limits or decision limits. As s-MMA depends on renal function (glomerular filtration rate, GFR), interpretation can be complicated. To ease the interpretation of the two measurements, we propose three new tools: First, we developed a new formula for adjusting s-MMA to an eGFR of 100 mL/min/1.73 m<sup>2</sup> (s-MMA<sub>100</sub>). The formula was s-MMA<sub>100</sub> = [(eGFR/100)<sup>0.549</sup>] × s-MMA. It was derived from the median relationship between s-MMA and estimated GFR (eGFR) in an ambulant patient population of 4342 individuals, where eGFR was calculated according to the EKFC equations. S-MMA<sub>100</sub> was not associated with eGFR in a US test population of 6852 individuals. Second, we constructed a combined reference range for s-MMA<sub>100</sub> and s-cobalamin from data in a healthy reference population (<i>n</i> = 495 individuals). Third, we proposed a new cobalamin deficiency index, CDI = s-cobalamin/s-MMA<sub>100</sub>, and studied the effect of different decision limits on the prevalence of positive test results in a patient population. Using the 2.5 percentile of CDI in the reference population as a decision limit gave a prevalence of 5.2% positive test results in the patient population. However, as a gold standard for cobalamin deficiency does not exist, we were unable to study the diagnostic accuracy of the CDI. Therefore, the true diagnostic accuracy of these tools is yet unknown and should be investigated.</p>","PeriodicalId":21474,"journal":{"name":"Scandinavian Journal of Clinical & Laboratory Investigation","volume":"85 2","pages":"101-107"},"PeriodicalIF":1.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143754395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tuba Saadet Deveci Bulut, Muhittin Abdulkadir Serdar, Mehmet Muhittin Yalçın, Meriç Coşkun, Aylar Poyraz, Seda Gökgöz Acar, Gizem Yaz Aydın, Özlem Gülbahar
{"title":"A deep dive into four thyroglobulin immunoassays from analytical perspective.","authors":"Tuba Saadet Deveci Bulut, Muhittin Abdulkadir Serdar, Mehmet Muhittin Yalçın, Meriç Coşkun, Aylar Poyraz, Seda Gökgöz Acar, Gizem Yaz Aydın, Özlem Gülbahar","doi":"10.1080/00365513.2025.2479037","DOIUrl":"10.1080/00365513.2025.2479037","url":null,"abstract":"<p><strong>Backgrounds: </strong>Serum thyroglobulin immunometric assays (sTg) are crucial for monitoring differentiated thyroid cancer (DTC) treatment. However, challenges such as anti-thyroglobulin autoantibodies (TgAb) and assay variability hinder evaluations. This study assessed four sTg methods-three second-generation (Architect, Access, Elecsys) and one first-generation (Immulite)-following Clinical and Laboratory Standards Institute (CLSI) and American Thyroid Association (ATA) guidelines.</p><p><strong>Methods: </strong>The study compared sTg<sub>(Architect)</sub>, sTg<sub>(Access)</sub>, sTg<sub>(Elecsys)</sub>, and sTg<sub>(Immulite)</sub>. Precision was evaluated per CLSI EP05-A3, while the lower limits of detection (LLD) were assessed using EP17-A2. Passing-Bablok and Bland-Altman analyses were conducted as per EP09c, and semi-quantitative comparisons used Kappa statistics.</p><p><strong>Results: </strong>The second-generation sTgs (Architect, Access, Elecsys) exhibited satisfactory precision (<7% coefficient of variation, CV%), unlike sTg<sub>(Immulite)</sub>, which showed significant deviations and inadequate sensitivity for DTC recurrence (Limit of quantitation, LoQ = 4.59 μg/L). Second-generation sTgs had strong correlations (<i>r</i> > 0.884) across all concentration ranges (≤1, 1-10, >10 μg/L), with biases (slope: 1.131-2.027). sTg<sub>(Immulite)</sub> correlated well with second-generation methods for concentrations >10 μg/L (<i>r</i> > 0.945) but less so for <10 μg/L (<i>r</i> < 0.642). TgAb significantly impacted sTg<sub>(Immulite)</sub>. Kappa statistics revealed strong agreement among second-generation methods (κ > 0.800) but lower concordance with sTg<sub>(Immulite),</sub> especially in TgAb(+) samples (κ: 0.562-0.653). Agreement ratios were high for second-generation methods (0.667-1.000) but variable for sTg<sub>(Immulite)</sub>, particularly at lower concentrations and in TgAb(+) cases (0.097-0.727).</p><p><strong>Conclusions: </strong>sTg<sub>(Immulite)</sub> did not meet LLD and precision criteria for DTC monitoring, facing issues with TgAb interference. Second-generation sTgs demonstrated consistent performance across all concentrations.</p>","PeriodicalId":21474,"journal":{"name":"Scandinavian Journal of Clinical & Laboratory Investigation","volume":" ","pages":"148-159"},"PeriodicalIF":1.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143650276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Short-term stability of routine coagulation tests under different storage temperatures in centrifuged whole blood samples: a practical approach.","authors":"Jacob Rudjord Therkildsen, Anders Abildgaard","doi":"10.1080/00365513.2025.2472423","DOIUrl":"10.1080/00365513.2025.2472423","url":null,"abstract":"","PeriodicalId":21474,"journal":{"name":"Scandinavian Journal of Clinical & Laboratory Investigation","volume":" ","pages":"168-171"},"PeriodicalIF":1.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143531662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hilda Hallander, Magnus Lindén, Catarina Lindqvist, Anders Olsson, Sara Marie Larsson
{"title":"Performance of enzymatic creatinine methods in the pediatric concentration range.","authors":"Hilda Hallander, Magnus Lindén, Catarina Lindqvist, Anders Olsson, Sara Marie Larsson","doi":"10.1080/00365513.2025.2460196","DOIUrl":"10.1080/00365513.2025.2460196","url":null,"abstract":"<p><p>Creatinine is a widely used clinical biomarker in adult and pediatric patients to estimate kidney function and glomerular filtration rate. There are however few recent studies that have addressed method performance in the creatinine range relevant for children. This study aimed to describe measurement performance in the pediatric concentration range by comparing commonly used enzymatic methods on four platforms: Abbott Alinity, Radiometer ABL800, Roche Cobas and Siemens Atellica, to the reference method isotope dilution mass spectrometry (IDMS). A secondary aim was to compare the Roche enzymatic methods by using dilutions of control sera issued by the Nordic Association of Clinical Chemistry. We found varying accuracy of the creatinine methods in the low concentration range. The relative difference between platforms, in an investigated range below 75 µmol/L, decreased as creatinine concentration increased. Using an absolute factor to correct for method bias as recommended by one of the manufacturers could hamper measurement trueness in the low concentration range. The <i>in vitro</i> diagnostic industry and stakeholders should strive towards creatinine measurement agreeability. Attention to the pediatric concentration range is needed when correcting for method bias.</p>","PeriodicalId":21474,"journal":{"name":"Scandinavian Journal of Clinical & Laboratory Investigation","volume":" ","pages":"93-100"},"PeriodicalIF":1.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143441754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}