Clinical chemistry最新文献

{"title":"Failure of Serum Immunofixation Electrophoresis to Detect Intact Monoclonal IgD Lambda Unraveled by Mass Spectrometry.","authors":"Louis Nevejan, Mark Perkins, Martine Vercammen, Thibault Vanhove, Michel Delforge, Xavier Bossuyt","doi":"10.1093/clinchem/hvae116","DOIUrl":"10.1093/clinchem/hvae116","url":null,"abstract":"","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":" ","pages":"1291-1293"},"PeriodicalIF":7.1,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142003797","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":"A-302 Evaluation of real-time PCR assays for detection of sexually-transmitted infections","authors":"H Soong","doi":"10.1093/clinchem/hvae106.299","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.299","url":null,"abstract":"Background Sexually transmitted infections (STIs) have serious negative consequences for reproductive health worldwide. They are associated with infertility, premature birth and neonatal infections. Five STI pathogens, namely Trichomonas vaginalis, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum were selected for the evaluation of three potential real-time PCR assays that can be adopted for diagnostic testing. Methods A total of 36 samples were included, consisting of genital swabs, urine, abscesses and samples provided by quality assurance programmes. DNA extraction was performed using an automated nucleic acid extraction system, abGenixTM. Commercial genomic controls and DNA extracts donated by external laboratories were used as well. The extracted nucleic acids were tested using three different assays, namely Seegene Anyplex II STI-5 Detection, Thermo Fisher Scientific customized STI Panel assay, and TIB MOLBIOL STI LightMix Modular kits, according to the manufacturers’ instructions. Results A total of 67% and 11% of the samples showed equivalent positive and negative results, respectively. However, 22% of the samples had non-concordant results. TIB MOLBIOL STI LightMix Modular kit was unable to differentiate between Ureaplasma parvum and Ureaplasma urealyticum in 9 samples. Genomic controls were tested, and Seegene Anyplex II STI-5 Detection was unable to detect lower concentrations of DNA for Trichomonas vaginalis, Mycoplasma genitalium and Mycoplasma hominis. All assays were able to detect lower concentrations of Ureaplasma parvum DNA, but detectable concentrations were higher for Ureaplasma urealyticum. Conclusions In conclusion, the performance of each assay differed according to pathogen. None of the assays offered equal performance for all pathogens. We have adopted Thermo Fisher Scientific customized STI Panel assay in our diagnostic testing due to its advantage of being user friendly and cost effective.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"23 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369088","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":"B-244 Analytical Performance and Method Comparison Evaluation of a New High Throughput Fully Automated Plasma GFAP Immunoassay","authors":"Z Vucetic, M Szabo, M Salvati, B Schlichtmann, J Patzlaff, D Unruh, K Curtis, L Mediger, M Nichkova-Doseva","doi":"10.1093/clinchem/hvae106.601","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.601","url":null,"abstract":"Background Glial Fibrillary Acidic Protein (GFAP) levels are shown to be an indicator of neurologic injury in conditions like Traumatic Brain Injury (TBI) and stroke and as a marker of disease progression in neuromuscular disorders such as multiple sclerosis. Plasma GFAP is also implicated in detecting AD pathology, correlating to the clinical stage of the disease. The performance characteristics of the plasma GFAP immunoassay currently being developed on Beckman Coulter Access 2 and DxI 9000 analyzers are described. Methods The prototype GFAP assay is a one-step sandwich assay utilizing an anti-GFAP mouse monoclonal (MAb) antibody/alkaline phosphatase conjugate and paramagnetic particles coated with a complementary anti-GFAP mouse MAb. Sample and reactants are incubated and washed, and then a chemiluminescent substrate is added. The light generated is directly proportional to the GFAP concentration in the sample. The assay time to the first result is ∼30 minutes. Analytical performance evaluation and method comparison across different platforms was performed. 43 EDTA plasma samples, consisting of 19 Alzheimer’s Disease (AD) patient samples and 24 age-matched healthy normal samples, were evaluated. Results The prototype GFAP assay has a targeted analytical measuring range of 1.0 pg/ml to approximately 700.0 pg/ml (up to 10,000 pg/ml). All normal samples were quantified with 90% measuring below 20.0 pg/ml and a low dose coefficient of variation <4.0%. A comparison of the prototype GFAP assay on DxI 9000 and Access 2 analyzers shows a Passing-Bablok slope of 0.94 (R=0.992) and an intercept of 0.37 pg/ml. Concordance analysis shows excellent agreement between the Access 2 and DxI 9000 assays. The dose ratio of the median of AD over the median of normal samples for Access 2 and DxI 9000 is 2.31 and 2.41, respectively, with AD patient median dose values of 14.3 pg/ml and 14.6 pg/mL, respectively, and normal sample median dose values of 6.2 pg/ml and 6.0 pg/mL, respectively. Conclusions The prototype GFAP assay provides fast, highly sensitive, and precise results in an automated immunoassay on the Beckman Coulter Access 2 and DxI 9000 platforms. The prototype plasma GFAP assay holds promise for diagnosing and monitoring various neurodegenerative diseases, including AD.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"23 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369120","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":"B-333 Optimizing AFP Cutoffs for Hepatocellular Carcinoma Screening: Insights from the National Cancer Screening Program in Korea","authors":"Y Choi, S Kim, H Kim, H Jeong, H Lee, W Lee, S Chun","doi":"10.1093/clinchem/hvae106.690","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.690","url":null,"abstract":"Background The incidence rate and mortality rate of liver cancer were 11.6 (ranked 8th among cancers) and 10.7 (4th) per 100,000 individuals respectively globally in 2020, whereas in Korea, they were higher at 29.5 (7th) and 20.6 (2nd) per 100,000 individuals. The National Cancer Screening Program (NCSP) in Korea conducts biannual concurrent liver ultrasound and serum alpha-fetoprotein (AFP) measurement for hepatocellular carcinoma (HCC) surveillance in high-risk groups, including those with chronic hepatitis B and C, and liver cirrhosis. The effectiveness of surveillance is impacted by varying AFP cutoffs; however, within the NCSP, different cutoffs are being used, and it is not clear which cutoffs are being employed. Harmonization of AFP test results by major reagent manufacturers have been achieved, enabling the adoption of a uniform threshold. This study aims to assess the variation of AFP cutoffs among institutions within the NCSP and suggest a unified and optimal AFP threshold. Methods This study examined HCC screening results from the NCSP between 2018 and 2020, investigating unit and cutoff usage for AFP test across institutions each year (number of institutions were 4452 for 2018, 4754 for 2019, and 4847 for 2020). To determine the optimal AFP cutoff for HCC screening, datasets comprised unique patient results from 2018 to 2020 (number of patients = 819,644). Receiver operating characteristic (ROC) curve analyses were conducted for determine best AFP cutoffs. Cancer diagnosis was defined by billing records indicating HCC within one year post-screening. Results More than 96% of institutions used ng/mL as a unit of AFP test. Among institutions using ng/mL, the most frequently used AFP cutoff was 7 ng/mL, with frequency percentages of 75.7%, 72.2%, and 62.2% in 2018, 2019, 2020, respectively. The percentiles (1st, 10th, 90th, 99th) of AFP cutoff usage for the years 2018, 2019, and 2020 were (7, 7, 8.8, 15), (7, 7, 8.9, 15), and (7, 7, 9, 15) respectively. The AUC of ROC was 0.824 and some cut-off points with their sensitivity and specificity values were as follows: 5 ng/mL (0.648, 0.874); 10 (0.457, 0.976); 20 (0.327, 0.993); 40 (0.246, 0.997); 100 (0.169, 0.998); 200 (0.123, 0.999); 400 (0.084, 1). Conclusions Different cutoffs observed across institutions in NCSP. Our study cautiously suggests that the optimal AFP value for screening HCC in NCSP may range from 10 to 20 ng/mL, considering sensitivity and specificity when AFP is combined with ultrasound in regions with a high prevalence of HCC. For a more suitable AFP cutoff recommendation, additional analyses based on ultrasound findings and underlying diseases should be considered.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"191 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368755","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":"B-008 An Evaluation of the Analytical Performance of the New Beckman Coulter DxC 500i Clinical Analyzer","authors":"B Tran, L Mindeman, M Reyes, P Kraght, K Lynch, M Meade, L Frost, T Rice, M Cavalleri, S Frost","doi":"10.1093/clinchem/hvae106.372","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.372","url":null,"abstract":"Background The DxC 500i Clinical Analyzer* is Beckman Coulter’s latest integrated Clinical Chemistry and Immunoassay analyzer. It provides reliability, scalability, and workflow efficiency via a flexible independent maintenance mode, increased uptime, and a dynamic sample handler to optimize sample management. Standard Beckman Coulter Chemistry and Immunoassay consumables and reagents ensure network standardization and commutability. The purpose of this study was to evaluate the analytical performance of the new DxC 500i analyzer and to compare the performance against the Beckman Coulter stand-alone Clinical Chemistry and Immunoassay analyzers on the market. Methods To assess performance over a range of assay methodologies, several DxC 500i Beckman Coulter Immunoassays and Chemistry assays were evaluated. Precision was assessed using human samples following CLSI EP05-A3 guidelines. Linear range was assessed following CLSI EP06-A guidelines. Method Comparison and Bias Estimation studies compared the DxC 500i Clinical Analyzer against the Access 2 Immunoassay System, the AU480 and the DxC 700 AU Clinical Chemistry analyzers, following CLSI EP09c-ED3 guidelines. To investigate carryover potential as samples are processed across the integrated system, a carryover study was designed. This focused on evaluating potential sample-to-sample carryover caused by the AU sample probe and its effects on immunoassay samples during reflex scenarios. Results DxC 500i Chemistry results: Glucose Serum (OSR6x21) Assessments of repeatability and within laboratory precision at multiple critical analyte concentrations showed total imprecision of <3% and within-run imprecision of <3%. The Glucose serum assay demonstrated acceptable linearity throughout the 10-800 mg/dL analytical measuring range. Method comparison studies compared the DxC 500i analyzer against the AU480 and DxC 700 AU systems. A Weighted Deming regression of serum patient samples (n>100 measured across the analytical range) yielded a 0.986 slope, 0.227 mg/dL intercept, and R=0.9999 correlation coefficient against the DxC 700 AU and a 0.995 slope, 0.356 mg/dL intercept, and R=0.9999 correlation coefficient against the AU480. DxC 500i Immunoassay results: Cortisol (33600) Beckman Coutler’s Cortisol assay exhibited total imprecision of <12%CV at <5 μg/dL or <10CV% at ≥5 μg/dL for serum. The Cortisol assay demonstrated acceptable linearity throughout the 0.4-60 μg/dL analytical measuring range. A method comparison study compared the DxC 500i against the Access 2 system. A Weighted Deming regression of serum patient samples (n>100 measured across the analytical range) yielded a 0.9785 slope, 0.2764 μg/dL intercept, and R=0.9932 correlation coefficient. DxC 500i Carryover Assessment The Total βhCG (5th IS) assay was used to evaluate the potential of chemistry analyzer to immunoassay analyzer sample carryover. The study used High hCG serum samples (>1,000","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"76 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142362984","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":"B-169 Combining the EXENT System and LC-MS for the Detection of Monoclonal Immunoglobulins at Low Levels","authors":"D R Barnidge, D Troske, S North, G Wallis, M Perkins, S Harding","doi":"10.1093/clinchem/hvae106.529","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.529","url":null,"abstract":"Background The EXENT® system is an automated platform designed to quantify monoclonal immunoglobulins in serum. EXENT® combines immunoprecipitation and MALDI-TOF mass spectrometry for the detection of monoclonal immunoglobulins at levels lower than traditional gel based methods. This study was designed to demonstrate if EXENT® prepared samples that were negative could be reflexed to a more sensitive method based on capillary flow Liquid Chromatography- Mass Spectrometry (LC-MS) without any modifications to the EXENT® prepared sample. Methods Patient samples containing a monoclonal immunoglobulin (ranging from 20 to 40 g/L) were diluted into pooled polyclonal serum and the samples were prepared and analyzed by EXENT®. Samples that were negative by EXENT® were reflexed by directly loading EXENT® eluates onto the LC-MS instrument. The abundance of the monoclonal immunoglobulin was defined by the signal-to-noise (S/N) of the light chain peak observed after deconvolution. Results Baseline samples were diluted down to two levels, 0.100 g/L and 0.001 g/L. LC-MS detected the same light chain from the monoclonal immunoglobulin as the EXENT® system in all reflexed samples that were negative by EXENT®. Conclusions LC-MS can detect monoclonal immunoglobulins that can no longer be detected using the EXENT® system by tracking the unique molecular mass of the monoclonal light chain. Reflexing samples to LC-MS did not require additional sample handling resulting in a faster time-to-result than current NGS, NGF, and clonotypic peptide approaches. Furthermore, monitoring the intact monoclonal light chain circumvents enzymatic cleavage to create a unique clonotypic peptide, alleviating a situation where no unique peptide can be generated as has been shown previously by Bergen et al. As a consequence, this reflex-methodology results in a consistent way of measuring the presence of malignant B-cells with high sensitivity.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"14 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369050","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":"A-345 Effect of Hemolysis on Routine Blood Gas Analytes","authors":"B Agana, B Overton, K Florendo, C Knezevic","doi":"10.1093/clinchem/hvae106.339","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.339","url":null,"abstract":"Background Hemolysis is a major pre-analytical concern for most laboratory analytes. Detection of hemolysis and mitigation efforts are especially important for analytes, such as potassium, with high intracellular concentrations. Routine serum and plasma chemistry tests are performed on analyzers with the capacity to detect and measure the degree of hemolysis. However, for whole blood chemistries and blood gas measurements, the instruments utilized lack this capacity. The aim of this study was to evaluate the effect of hemolysis on whole blood and blood gas analytes and to compare visual assessments of hemolysis to measured hemolysis indices (H-index). Methods Remnant whole blood samples were split into two portions and each portion was aspirated and dispensed through a syringe one or more times. For the mock portion, only the syringe was used, while the hemolyzed portion had a needle affixed to the end of the syringe. The needle provided shear stress on the red blood cells to induce hemolysis, while the mock procedure was used to assess the impact of aspirating/dispensing on the sample in the absence of hemolysis. Each portion was then analyzed on a Radiometer ABL800 series instrument, spun down, and the H-index of the plasma portion was measured on a Roche cobas 8000 instrument. Medical technologists recorded their visual assessment of the specimens, with two technologists agreeing to the categorization of the specimen as either slightly, moderately, or severely hemolyzed. Degree of hemolysis was categorized by the delta (hemolyzed - mock) of the measured H-index: slight hemolysis was defined as an H-index delta of <100, moderate as 100-500 and severe as >500. Results The effect of hemolysis, with H-indices ranging from 2 to 3861, on 13 routine blood gas analytes was studied for 85 whole blood specimens. Hemolysis had little effect on metabolites, as percent bias was within ±3% at all levels of hemolysis for glucose, creatinine, and lactate. Similarly, most cooximetry components were minimally affected, with total hemoglobin, oxyhemoglobin, carboxyhemoglobin, and oxygen saturation within ±5% bias at all levels of hemolysis. Methemoglobin had a larger overall negative bias, with slight, moderate, and severe hemolysis levels yielding percent biases of -6.6, -12.3, and -13.3%, respectively. As expected, potassium displayed a significant positive bias with increasing hemolysis, with a generally linear trend. At moderate levels of hemolysis, the average potassium bias was 24.0% and at severe levels, over 100%. Sodium and ionized calcium also displayed overall linear trends but with a negative bias. At slight, moderate, and severe levels of hemolysis, sodium had a -0.56, -1.10, and -3.96% bias, and ionized calcium had a -2.99, -5.65, and -15.5% bias respectively. Conclusions Hemolysis can falsely increase or decrease a range of blood gas analytes and lead to misinterpretation of results and adversely affect clinical decision-making. Ther","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"4 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369053","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":"A-319 Capillary Blood Collection for Egg-cellent Reproductive Insights","authors":"W C Brandon, B B Collier, M R Chappell, G Iacovetti, M Peevler, U Y Schaff, G J Sommer, R P Grant","doi":"10.1093/clinchem/hvae106.314","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.314","url":null,"abstract":"Background In the United States, an estimated 13% of women between the ages of 15 and 49 years, experience impaired reproductive potential (fecundity). Assessment of fecundity typically requires an in-person physician visit and venous blood collection to evaluate hormone levels and identify potential reproductive health conditions. Exploring less invasive, at-home sampling options could offer couples insights into their personal reproductive abilities, providing peace of mind and aiding in family planning. Methods Capillary blood, obtained using the Tasso®+ capillary blood collection device coupled with a BD Microtainer® serum tube, was utilized for measurements of analytes associated with female fecundity (follicle stimulating hormone, luteinizing hormone, estradiol, progesterone, anti-Müllerian hormone, and prolactin). These are all FDA-approved assays measured on Roche cobas® e801, assay parameters remained unchanged. Professional and self-collected capillary serum samples were acquired in parallel with the standard venous serum samples, to compare clinical equivalency of the capillary sampling option. In addition to isothermal stability studies at room temperature (20-25°C) and refrigerated (2-8°C) conditions, shipping excursion studies based on ISTA 7D recommendations were performed using a novel packaging solution to control sample temperature and thus, specimen integrity. Studies to assess matrix equivalency, linearity, and imprecision of this alternate sample type were also performed to demonstrate analytical performance. Results Method comparison of venous and professional collection of capillary samples demonstrated correlations (R) ≥ 0.9720 with slopes ranging from 0.919 to 0.971 and mean biases within ±8.2% for all analytes (n = 19-79). Self-collected capillary serum samples demonstrated correlations (R) ≥ 0.9827 with slopes that ranged from 0.841 to 0.985 and mean biases within ±10.7% (n = 16-26). Isothermal stability was demonstrated for each analyte up to 7 days at room temperature and refrigerated conditions. Simulated shipping excursion results were found to be acceptable for both winter and summer conditions with mean biases for each analyte within ±10.2% and ±19.2%, respectively. Matrix equivalency, linearity, and imprecision results adhered to current CLIA acceptance limits for each respective measurement. Conclusions The analytical and stability results affirm the feasibility of collecting capillary serum in a patient-centric manner, providing women with relevant information about their reproductive health.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"23 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369087","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":"A-104 Study of the matrix effect for thyroglobulin and calcitonin in fine-needle aspiration of cervical nodules","authors":"D Canali, G Zampieri, C Bonato, G Francisco, C Sabino, V Oliveira, A Lopes","doi":"10.1093/clinchem/hvae106.103","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.103","url":null,"abstract":"Background Analysis of material from fine needle aspiration of cervical thyroglobulin nodules with Beckman Coulter reagents on the ACCESS equipment and Calcitonin using the Siemens reagent on the Immulite equipment. The matrix effect, linearity and the limit of analytical sensitivity were analyzed. This study aims to analyze the correlation between the serum/plasma results described in the suppliers' package inserts with the results obtained with the puncture matrix. Methods The performance characteristics were tested according to the laboratory's operating procedures, based on the recommendations of ANVISA RDC 166/2017. Such parameters involved doping, which corresponds to the introduction of a calibrator with a known and traceable value into a pool of puncture material that is known to be negative, in order to analyze the behavior of the results obtained, paying attention to the deviations that may eventually occur due to the interference of the characteristics of the puncture material. puncture. After doping the material, dilutions were performed up to the sensitivity limit of the test, also analyzing the functional sensitivity, where ten replicates of the material were dosed, thus obtaining CV%, mean and Standard Deviation values. The same process was carried out and evaluated using the serum material. During the entire process, the materials received and analyzed were centrifuged and always kept in a refrigerated environment. Results The recovery% of the matrix effect study for cervical aspirate puncture showed results within the expected range, ranging from 80% to 120%, as well as the results compared with serum/plasma referenced in the supplier's package insert. The functional sensitivity study for Thyroglobulin showed a CV% of 1.77%, being lower than that recommended by the package insert (2.2%) and for the Calcitonin analyte, the functional sensitivity study showed a CV% of 8.49%, being lower than recommended by the package leaflet (15.7%), in addition to having CV's lower than the 20% recommended by ANVISA. The results obtained with the matrix effect study for serum also showed values between 80% and 120%, both of which agreed. Conclusions The results showed excellent performance for material from fine needle aspiration for both Calcitonin and Thyroglobulin, being consistent with the serum data described by the suppliers' package inserts, thus making the reagent usable for the cervical aspirate puncture matrix.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"77 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368756","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":"A-306 High Sensitivity Capability of an Anti-müllerian Hormone Assay on the Beckman Coulter DxI 9000 Immunoassay Analyzer*, a Next Step Toward Enabling Ovarian Failure Staging?","authors":"S Kuklok, J Thomforde, L Pearson, K Pritchard, T Pfingston, C Bunkelman, L Pearson, T Her, B Bolstad, B Bilyeu, S Santiago, S Thornburgh, M Posnansky, N Malikowski-Hoffarth, K Walt, D Lovett, M Holland, M Szabo, C Carlson","doi":"10.1093/clinchem/hvae106.301","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.301","url":null,"abstract":"Background Measurement of anti-müllerian hormone (AMH) has proven value in the evaluation of ovarian reserve using assays such as the Beckman Coulter Access AMH assay. If improved sensitivity of AMH measurement can be achieved, enhanced clinical utility during the assessment of reproductive aging and ovarian response to enable staging of ovarian failure is possible (Practice Committee of the American Society of Reproductive Medicine 2020, Cappola et al. 2023). The Beckman Coulter DxI 9000 Immunoassay Analyzer* has been designed with new technology that can be leveraged to improve assay sensitivity. Such technological advancements include the new Lumi-Phos PRO chemiluminescent substrate which yields markedly increased signal-to-noise, a new luminometer with increased dynamic range, and improved low-volume pipetting capabilities. Data herein summarize results from analytical verification studies of the Access AMH assay on the DxI 9000 Immunoassay Analyzer. Results demonstrate an example of DxI 9000 technologies enabling sensitivity claims that are up to 20-fold improved. * The official name is DxI 9000 Access Immunoassay Analyzer. Methods A method comparison study was performed based on CLSI guideline EP09c, 3rd ed. to compare results for the Access AMH assay on DxI 9000 to the predicate device, the Access AMH assay on the Access 2 Immunoassay System. Within-laboratory precision was also evaluated following CLSI EP05-A3. Finally, performance at low analyte levels was evaluated following CLSI EP17-A2, and linearity was evaluated following CLSI EP06-Ed2. Results Method comparison of the Access AMH assay on DxI 9000 compared to the Access AMH assay on the Access 2 yielded excellent agreement with a Passing-Bablok slope of 1.02 for N=126 samples. Further, bias estimates for a number of key medical decision points suggest minimal bias (≤ 2%) across the assay range, and minimal non-linearity was observed. 20-day imprecision studies yielded CV’s between 2 and 5% across a broad range of concentrations evaluated. Sensitivity studies yielded estimates of limit of quantitation (LoQ) between 0.001 and 0.003 ng/mL. This represents an approximately 10- to 20-fold improvement in sensitivity claims compared to the AMH assay on the Access 2 and other commercially available automated immunoassay analyzers. Conclusions The data herein present performance data for the Access AMH assay on the DxI 9000 Immunoassay Analyzer. The assay demonstrates excellent accuracy relative to the predicate device, while showing good linearity and imprecision. Of note, the Access AMH assay exhibits exceptional low-end performance on the DxI 9000 analyzer as demonstrated by the ability to enable sensitivity claims that are up to 20-fold improved in comparison to existing immunoassays for the measurement of AMH. The sensitivity capabilities of the Access AMH assay on DxI 9000 suggest an opportunity for the addition of further intended uses for scenarios where extremely low AMH measurement","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"26 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368791","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}