Clinical chemistry最新文献

{"title":"A-381 Nanowire assisted fluorescence immunoassay (FLIA): Enabling low-cost, high-sensitivity biomarker assays for expanded clinical utility","authors":"Kenneth Harlow, Karin Blume, Felicia Andersson, Liu Guanghui, Søren Echwald, Niklas Mårtensson","doi":"10.1093/clinchem/hvaf086.365","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.365","url":null,"abstract":"Background The ability to make rapid and early clinical decisions regarding diagnosis and therapy is often highly correlated with the ability to detect one or more specific disease-relevant biomarkers early and at very low concentrations during the onset of a particular illness. High-sensitivity immunoassays employing various methodologies have been instrumental in pushing the limits of detection for immunoassay techniques to lower values for many disease-relevant biomarkers. This in turn has allowed clinicians to make relevant diagnostic and therapeutic decisions earlier than possible when using more conventional immunoassay methodology. The unique ability of semiconductor nanowires of specific diameters to enhance and amplify the fluorescence of fluorescent reporter molecules provides a generic way to increase the sensitivity of fluorescent immunoassays (FLIA) and has allowed us to demonstrate a generically applicable mode of FLIA enhancement using semiconductor nanowire arrays. Nanowire enhanced fluorescence thus provides a general way to extend the utility of FLIAs to achieve earlier clinical decision points and improve treatment and clinical outcome. Methods Arrays containing silicon nanowires with dimensions designed to interact with specific wavelengths of light were fabricated and used as substrates for performing sandwich type FLIAs for a variety of protein biomarkers. A range of biomarkers including CEA, Troponin and IL-6 were employed in order to evaluate how general the sensitivity enhancement effects were across different analyte assays. Commercially available antibodies and reagents were used to set up the immunoassays used in these studies. FLIA assays were performed on these nanowire array substrates using standard immunochemical procedures. Following assay for a particular biomarker analyte on the nanowire arrays, the arrays were imaged using low magnification in an inverted fluorescence microscope to record the spatial distribution and intensity of fluorescent signals present on the arrays. These images were further analyzed using a proprietary analysis algorithm to extract values for total fluorescence intensities, and to locate and enumerate the number of fluorescent nanowires and to determine the average fluorescence intensity per nanowire. These values were then used to calculate concentrations of analytes present in calibrator solutions. Results In general, we were able to demonstrate an enhancement in sensitivity of from 20 to 200-fold over the same assay conducted on a planar material such as plastic or glass and using the same reagents. In addition, we observed extended dynamic ranges compared to assays run on planar surfaces often with dynamic ranges of 6-7 orders of magnitude. Fluorescent intensity measurements of individual nanowires at low concentrations were constant over a range of concentrations while the number of fluorescing nanowires increased with increasing concentrations at these low levels. This suggests si","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"39 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203152","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-058 Evaluating the analytical performance of the OsmoPRO® MAX Automated Osmometer","authors":"Lisa Salvucci","doi":"10.1093/clinchem/hvaf086.456","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.456","url":null,"abstract":"Background Accurate and timely serum, plasma, and urine osmolality measurements are crucial for diagnosing and treating conditions such as hyponatremia, toxic alcohol ingestion, and diabetes insipidus. Most clinical osmometers rely on manual methods which require pipetting and testing one sample, control, or calibration standard at a time. These manual steps are time-consuming and increase the risk of human error. A new osmometer, the OsmoPRO® MAX, saves time and reduces these risks by automating freezing-point depression measurements (Advanced Instruments, LLC). The purpose of this study was to evaluate the analytical performance of the OsmoPRO MAX in measuring the osmolality of serum, plasma, and urine. Methods OsmoPRO MAX analytical performance was evaluated at Boston Medical Center in Boston, Massachusetts using four criteria: (1) Linearity was assessed with an allowable systematic error of <2 mOsm/kg H2O and an allowable total error of <6.0 mOsm/kg H2O over a range of 0-2000 mOsm/kg H2O using an Osmolality Linearity Set. (2) Simple Accuracy was evaluated over a range of 240 to 800 mOsm/kg H2O using Clinitrol™ 290 with an acceptable range of +/- 4 mOsm/kg H2O as well as Protinol™ 240, 280, and 320, each with an acceptable range of +/- 7 mOsm/kg H2O, and Renol™ 300 and 800, both with an acceptable range of +/- 10 mOsm/kg H2O. (3) Simple Precision was measured using Clinitrol 290 with an acceptable within-run standard deviation (SD) of <2.0 mOsm/kg H2O as well as Protinol 240, 280, and 320, each with an acceptable within-run SD of <3 mOsm/kg H2O, and Renol 300 and 800, with an acceptable within-run SD of <3 mOsm/kg H2O and <4.7 mOsm/kg H2O, respectively. (4) Alternative Method Comparison was conducted against the OsmoPRO® Multi-Sample Micro-Osmometer on 80 patient samples analyzed by Passing-Bablok regression analysis. Results OsmoPRO MAX passed all criteria. Linearity testing produced a negligible observable error of 0.1 mOsm/kg H2O, accurate within the allowable systematic error and all results were accurate within the total allowable error. Simple Accuracy testing produced replicates all within their specified target range. Simple Precision testing of all replicates for each standard tested fell within their respective within-run SD. Alternative Quantitative Method Comparison demonstrated strong agreement between the two methods with a correlation coefficient of 0.9998 and a bias of -2.1 (-0.6%). Conclusion This study demonstrates that the OsmoPRO MAX Automated Osmometer meets all acceptance criteria for analytical performance including linearity, simple accuracy, simple precision, and alternative quantitative method comparison against the OsmoPRO Multi-Sample Micro-Osmometer.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"109 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203153","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-123 Nascent ADAM17 synthesis potentiates GPIba cleavage in resting and stimulated stored platelets","authors":"Shayan Askari, Lawrence Goldfinger","doi":"10.1093/clinchem/hvaf086.119","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.119","url":null,"abstract":"Background Platelet concentrates stored at room temperature have a shelf life of five days. During storage, platelets undergo glycoprotein cleavage by metalloproteases, notably ADAM17 cleavage of GPIba, which leads to decreased post-transfusion reactivity and recovery. Aim: To investigate putative ADAM17 synthesis and its contributions to GPIba proteolysis in stored platelets. Methods Human platelets maintained in autologous plasma were treated on day 1 of storage with naked endonuclease-resistant ADAM17 siRNA and monitored for molecular and cellular effects. Platelet-specific Adam17-deleted mice were generated and dynamics of GpIba cleavage were assessed. Results Platelets translated nascent ADAM17 during storage as evidenced by increased expression blocked by puromycin, and by metabolic labeling with azidohomoalanine, coinciding with progressive GPIba ectodomain cleavage. SiRNA treatment suppressed ADAM17 translation, and rescued total but not surface levels of full-length GPIba in resting platelets during storage. Flow cytometry and confocal microscopy in permeabilized platelets confirmed the existence of an internal pool of GPIba as suggested by prior EM studies. Stimulation of washed platelets with thrombin or calcium ionophore led to 27.3 ± 4.7% and 47.5 ± 0.96% decrease in surface GPIba, respectively. Platelet pre-treatment with cell-permeable ADAM17 inhibitor KP-457 protected GPIba from ectodomain cleavage following platelet stimulation. However, cell-impermeable 5G6 antibody against the scissile domain of GPIba failed to protect GPIba upon platelet stimulation. ADAM17 siRNA did not alter thrombin-induced decrease in surface GPIba across 5 days in storage. However, surface GpIba was increased in resting and thrombin-stimulated Adam17-deleted murine platelets. Adam17-deficient platelets showed similar lifespan to wild type platelets as assessed by in vivo pulse chase labeling. Conclusions: An internal pool of GPIba, possibly in the open canalicular system (OCS), is exposed upon platelet stimulation but subject to rapid cleavage by ADAM17. Chemical inhibition or genetic deletion of ADAM17 allows the internal reservoir of GPIba to reach the surface in stimulated platelets. However, the pool of existing, siRNA-resistant ADAM17 is sufficient to cleave GPIba upon stimulation in stored platelets.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"24 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203214","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-372 The diagnostic value of serum RNA m6A methylation and microRNAs in hepatocellular carcinoma","authors":"Jiawei Zhang, Qishui Ou, Can Liu, Junjie Lai, Fuguo Zhan","doi":"10.1093/clinchem/hvaf086.757","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.757","url":null,"abstract":"Background Hepatocellular carcinoma (HCC) is a malignant neoplastic disease characterized by high clinical incidence and mortality. The prognosis for HCC remains poor mainly due to the challenging in early diagnosis. It is urgent to identify reliable biomarkers for early detection to improve prognosis of HCC. N6-methyladenine (m6A) modification of RNA has emerged as an important regulatory mechanism in various cancers, including HCC. It alters the stability, translation, and splicing of RNA and further influences development and progression of cancers. The microRNAs are involved in the initiation and progression of HCC through regulating gene expression. Abnormal expression of specific microRNAs can serve as biomarkers for HCC diagnosis and prognosis. This study aims to investigate the role of m6A modification in HCC development and identify microRNAs with significant expression differences in HCC patients. A nomogram model based on serum expression levels was developed to predict HCC risk and assess its diagnostic efficacy, providing valuable insights for early detection and more personalized management of HCC. Methods Twenty-four HCC patients and 22 matched healthy individuals were enrolled. The overall level of serum m6A was measured using an RNA m6A level detection kit. The expression levels of m6A modifying enzymes METTL3, BCDIN3D, as well as liver cancer-related microRNAs (microRNA-122, microRNA-198, microRNA-361, microRNA-378 and microRNA-532) were assessed by qRT-PCR. Each index was compared between patients and controls. Risk factors related to the incidence of HCC were identified using multivariate logistic regression analysis, and a nomogram model was constructed to predict HCC risk. Results Univariate analysis revealed that the overall level of m6A modification was down-regulated in HCC patients (0.0015 vs 0.0030, p=0.0015). The expression of microRNA-122, microRNA-198 and microRNA-532 was significantly higher in HCC patients (p<0.05). Multivariate logistic regression analysis identified m6A level (OR=0.288, 95%CI:0.123-0.676, P=0.004), microRNA-122 expression (OR=1.338, 95%CI:1.006-1.779, P=0.045) and microRNA-532 expression (OR=1.403, 95%CI:1.011-1.947, P=0.043) as independent risk factors for HCC. Two prediction models for HCC based on these indicators were developed: the m6A + microRNA-122 model (AUC=0.849, 95%CI=0.738-0.961) and the m6A + microRNA-532 model (AUC=0.847, 95%CI=0.730-0.963). Both models were internally verified by Bootstrap self-sampling method with the C-index value of 0.85, indicating good discrimination. Calibration curves showed a good fit, and decision curve analysis confirmed that the nomogram model provided greater clinical benefit than using single risk factors. Conclusion Serum RNA m6A modification is significantly decreased in HCC patients, while the expression of microRNA-122, microRNA-198, and microRNA-532 is elevated, which could be of value for the diagnosis of HCC. In addition, RNA m6A, microRN","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"17 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203357","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-105 A New Recombinant Human Albumin Produced in Thermothelomyces heterothallica (C1) Demonstrates Comparable Surface Binding to Native Serum Albumin","authors":"Audrianna Kern, Adam Okerlund, Charlotte Kunkler, Christopher Warner","doi":"10.1093/clinchem/hvaf086.503","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.503","url":null,"abstract":"Background Human serum albumin (HSA) and bovine serum albumin (BSA) are commonly used as a blocking agents in immunoassays to prevent non-specific surface binding, thereby reducing background signal and increasing assay sensitivity. However, these native albumins present challenges such as donor dependency, lot-to-lot variability, and contamination with plasma-derived molecules (e.g., vitamins, hormones, growth factors, antibodies/Ig), which can affect assay performance and reproducibility. Recombinant human albumin (rHA) offers a potential alternative by providing the same binding and blocking characteristics as native albumin without the limitations. A new rHA produced in Thermothelomyces heterothallica (C1) and purified using a scalable proprietary process may mitigate these challenges. This study aims to evaluate the amount of binding on different surfaces of this new rHA compared to native albumins to determine the viability of rHA as a surface blocker in immunoassays. Methods The amount of albumin binding to different surfaces was assessed using a bead binding assay. Here, albumin (rHA, HSA, BSA) was incubated with commercially available Dynabeads: hydrophilic (carboxylic acid or amine functionalized) and hydrophobic (tosylactivated). The amount of protein bound to the beads was determined by heating the coated beads in a denaturing buffer and quantifying via densitometry on an SDS-PAGE gel against a standard curve. Statistical analysis was performed using GraphPad Prism, with data presented as the mean of at least three independent replicates with standard deviations. A two-tailed t-test was used to determine statistical significance at the 95% confidence interval. Results All tested albumin products demonstrate 10-fold more protein binding to the hydrophobic beads than either of the hydrophilic beads, highlighting the chemical similarities of albumin from different sources. For both hydrophilic bead types, all tested albumins demonstrated statistically the same amount of binding, ranging from 0.10-0.23 µg and 0.19-0.23 µg for the carboxylic acid and amine beads, respectively, with rHA at 0.15 ± 0.06 µg and 0.23 ± 0.07 µg. The hydrophobic beads had a much larger range of albumin binding, from 1.4-3.7 µg, with rHA being at the lower end of the range at 1.4 ± 0.2 µg, but statistically the same as BSA and two HSA products. The large differences in binding of the native albumins showcase the variability of natively derived products from different producers. Even with these slight differences, these data demonstrate rHA has comparable surface binding chemistry to native albumins. Conclusion This new rHA produced by C1 and purified in a scalable process binds surfaces comparably to commercially available native albumin products on all surfaces tested. These results support the use of rHA as an alternative to native albumins in diagnostic applications, providing effective surface binding without the limitations associated with plasma-derived prod","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"101 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203695","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-122 Discrepant transglutaminase IgA results between Bioplex 2200 and Phadia 250 assays","authors":"Katherine Turner, Karie McDonald","doi":"10.1093/clinchem/hvaf086.519","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.519","url":null,"abstract":"Background Transglutaminase (tTg) IgA plus total IgA is the recommended screening test for patients over two years old for Celiac Disease. Other tests, such as Endomysial IgA (EMA), may be useful in diagnosing patients when the tTg IgA is equivocal due to the higher specificity of EMA compared to tTg IgA. For patients with Celiac Disease, tTg IgA is a useful marker to monitor disease activity when subscribing to a gluten-free diet. To consolidate antibody testing to a single vendor, tTg IgA was moved from a Phadia 250 assay (EliA Celikey IgA) to a Bioplex 2200 assay (Celiac IgA). Methods To verify the accuracy of tTg IgA on the Bioplex 2200 assay, 65 residual patient sera samples were analyzed on both the Phadia 250 and Bioplex 2200 assay. Results 90.7% were qualitatively concordant between instruments (table 1). Conclusion In our laboratory we offer a Celiac Cascade consisting of tTg IgA plus total IgA. In the cascade when tTg IgA is equivocal it is reflexed to EMA. With the implementation of the Bioplex 2200 assay there is no longer an equivocal range. In our accuracy study we identified a small cohort of patients that tested equivocal on the Phadia 250 assay (7-10 U/mL) and as low positives on the Bioplex 2200 assay (reference range <15 U/mL). The five samples that were equivocal on the Phadia 250 assay resulted in a median (min, max) Bioplex 2200 result of 34.4 U/mL (29.6-73.3). As a result, we modified our cascade so any weakly positive tTg IgA (15-30 U/mL) will reflex to EMA. Post go-live there have been three clinical reports of Celiac Disease patients adhering to a gluten-free diet who tested either as high negative or equivocal on the Phadia 250 assay before the assay transition and are now weakly positive (<30 U/mL) on the Bioplex 2200 assay with a negative EMA. In conclusion, it is recommended that if the tTg IgA is a low positive (15-30 U/mL) by the Bioplex 2200 assay, reflex to EMA. If the EMA is negative, it can be concluded that the patient does not have active disease and is most likely compliant with a gluten-free diet.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"28 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203211","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-279 False positive results for the CEDIA™ Mitragynine Immunoassay caused by methadone and EDDP in clinical specimens","authors":"Zhe Cheng, Lixia Chen","doi":"10.1093/clinchem/hvaf086.666","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.666","url":null,"abstract":"Background Mitragynine is an indole-based opioid-receptor agonist and the most abundant active alkaloid in the plant Mitragyna speciosa, commonly known as kratom. It is consumed for its pain-relieving and euphoric effects, but also known to be an abused and dangerous drug, which causes psychotic addiction and other adverse effects such as respiratory depression, liver toxicity, and death. In recent years, mitragynine has been associated with multiple deaths through illicit use and suspected adulteration with other drugs. Consequently, health care providers are interested in having mitragynine included in comprehensive drug testing panels for patients in treatment programs for substance use disorder and pain management. To evaluate the Thermo Scientific™ CEDIA™ Mitragynine (Kratom) homogeneous enzyme immunoassay (IA, Thermo Fisher Scientific Inc., Fremont, CA) as a presumptive screening tool and to compare results with a definitive liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for mitragynine and identify possible interferants causing false positive results. Methods Urine specimens submitted between September 2024 and November 2024 were qualitatively assayed by the CEDIA Mitragynine immunoassay on a Beckman Coulter AU 5800 series chemistry analyzer. The instrument was calibrated daily using 20 and 50 ng/mL calibrators with quality control material at 37.5 and 62.5 ng/mL. All presumptive positive screening results at 50 ng/mL cutoff were assayed for mitragynine by LC-MS/MS using CLIA validated method and specimens with discrepant results were identified. The IA was challenged with approximately 150 potentially interfering substances at a concentration of at least 10 µg/mL. Methadone and its metabolite EDDP were quantitatively assayed by LC-MS/MS at 100 ng/mL cutoff. Results The precision of the IA around the cutoff demonstrated a within-run coefficient of variation (CV) of 2.56% at 37.5 ng/mL, 1.71% at 50.0 ng/mL, and 1.70% at 62.5 ng/mL. The following drugs produced positive results for mitragynine: methadone (100 µg/mL), EDDP (100 µg/mL); kratom constituents: speciociliatine (10 µg/mL), speciogynine (25 µg/mL), paynantheine (25 µg/mL); and mitragynine metabolites: 7-hydroxy-mitragynine (10 µg/mL), 16-carboxy-mitragynine (10 µg/mL). No carry over was observed at mitragynine concentrations 200× cutoff. In total, 395 patient urine specimens tested positive by IA. Using LC-MS/MS with a lower reporting limit of 2 ng/mL for mitragynine, 346 (87.6%) specimens were confirmed positive and 49 (12.4%) were negative. Of the 49 discrepant specimens that were false positive by IA, 23 has been ordered for methadone and EDDP: 19 specimens showed methadone and EDDP positive results (82.6%), 4 specimens were methadone and EDDP negative (17.4%). The other 26 has no methadone and EDDP data available. Conclusion High concentrations methadone and its metabolite EDDP may interfere and cause false positive results for mitragynine screening using the CE","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"101 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203356","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-018 Validation of Pericardial Fluid on the Roche Cobas c702 Analyzer: Enhancing Standardization and Efficiency in Clinical Laboratories","authors":"Shaimaa Maher, Suttida Parnprome, Giancarlo Rodriguez, Erica Fermon, Imir Metushi, Lu Song","doi":"10.1093/clinchem/hvaf086.018","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.018","url":null,"abstract":"Background The accumulation of fluid in the pericardial sac, known as pericardial effusion, can result from a variety of medical conditions such as infections, injuries, autoimmune diseases, cancer, and renal failure. Accurate and precise biomarker analysis of pericardial fluid may be helpful in identifying the underlying causes of fluid accumulation. While pericardiocentesis is performed to relieve cardiac pressure and prevent tamponade, the diagnostic potential of pericardial fluid remains underutilized. The analysis of key biomarkers in pericardial fluid, such as albumin, amylase, blood urea nitrogen, cholesterol, direct bilirubin, lactate, lactate dehydrogenase, total bilirubin, and total protein can provide valuable insights into the etiology of pericardial effusion. However, pericardial fluid is not currently an approved specimen type for any tests available on automated chemistry analyzers. This study aims to validate the analysis of these key analytes to establish their analytical performance following the guideline form The College of American Pathologists (CAP) for body fluid that includes accuracy, precision, analytical measuring range (AMR), reportable range, sensitivity, specificity, interferences and stability. Methods Residual pericardial specimens originally obtained for cytology analysis were used to evaluate the analytical performance of nine biochemical analytes on the Roche Cobas c702 analyzer. The matrix effects of pericardial fluid on the measurement of the nine analytes were assessed by recovery studies. Samples of pericardial fluid containing various concentrations of an analyte was prepared by spiking a pericardial fluid with a known amount of the analyte in a ratio no less than 9:1 (volume of pericardial fluid to volume of the standard solution). Recovery was calculated by the ratio of the measured and the expected concentration of an analyte. Linearity was established using five samples with various concentrations of an analyte spanning the AMR. Intra and inter-assay precision were determined at three levels (L1, L2, and L3) near the clinical decision level, a lower and a higher level, respectively. Intra-assay was determined by testing each level 20 times, while inter-assay was assessed through quadruplicate(4X) analyses over 5 days. Interference studies assessed the effects of hemoglobin (101, 203, 602, and 1213 mg/dL), bilirubin (5.9, 12.2, 20.1, and 33.3 mg/dL), and triglycerides (120, 478, 1142, and 1707 mg/dL) on the measurement of these analytes. Results Recovery studies showed that values were within the acceptable limits (90% to 110%), showcasing reliable performance in pericardial fluid (Figure 1). Precision at various levels meet the acceptance criteria with coefficient of variation (CV) within 10%. Linearity of each analyte demonstrated a slope of >0.998 for all analytes, exhibiting an excellent linear response for all analytes tested. No significant interference was found for all nine analytes except","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"3 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203360","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-350 Diagnostic performance of the EXENT® System in monoclonal gammopathy","authors":"Gabriella Lakos, Syreeta Allen, Gemma Malin, Cristina Simion, Habib El-Khoury, Julia Colchie, Luca Bertamini, Grace Fleming, Erica Horowitz, Irene Ghobrial, Kaleb McLendon, Zianya Solis, John Roback, Andrew Neish, Sarah Grewal, Ashutosh Wechalekar, David Foureau, Manisha Bhutani, Victor Iliev, Oscar Berlanga","doi":"10.1093/clinchem/hvaf086.736","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.736","url":null,"abstract":"Background The Immunoglobulin Isotypes (GAM) Assay for the EXENT Analyser (The Binding Site, part of Thermo Fisher Scientific) offers sensitive detection, isotyping and quantification of M-proteins. We aimed to assess the clinical performance of the EXENT System (The EXENT Analyser and the Immunoglobulin Isotypes (GAM) Assay for the EXENT Analyser) as an aid in diagnosis of multiple myeloma (MM) and associated disorders. Methods The study included 1135 patients: 718 with monoclonal gammopathy (215 MM, 152 smoldering MM (SMM), 243 monoclonal gammopathy of undetermined significance (MGUS), 53 Waldenström’s Macroglobulinemia (WM), and 55 AL amyloidosis), and 417 disease controls. Clinical diagnoses were defined per appropriate international guidelines. Except for 20 AL amyloidosis patients, all monoclonal gammopathy patients were from the US population. The monoclonal gammopathy cohort had a 1:1 male/female ratio and was ethnically diverse (341 White; 264 African American/ Black; 43 Asian; 17 Hispanic; 53 unknown). The M-protein was IgG in 359 patients, IgA in 95, IgM in 97, light chain-only in 89, IgD in 2; 64 patients had more than one M-protein, and no M-protein was reported by electrophoretic methods in 9 cases. Two IgA, and one IgM patient had heavy chain identified only. In the disease control patients, the diagnosis of monoclonal gammopathy had been ruled out. Serum samples were analyzed at three testing sites using the EXENT System. Diagnostic sensitivity and specificity were calculated based on categorizing results as positive or negative with the EXENT System. A positive result was defined as the presence of an M protein which was either an intact immunoglobulin (IgG>/=0.359 g/L; IgA>/=0.325 g/L; IgM>/=0.227 g/L) or a light chain-only. These isotype-specific cut-off values were established on samples from 364 apparently healthy US subjects for IgG, IgA and IgM M-proteins using the 95th percentile limit for IgG, and the 99th percentile limit for IgA and IgM. A negative result was defined as no M-protein by the EXENT System; or if intact immunoglobulin M-proteins were present, the concentration was below the corresponding isotype-specific cut-off. Diagnostic sensitivity and specificity with 95% confidence interval (CI) were calculated for each diagnosis (MGUS, SMM, MM, WM and AL amyloidosis) separately, and on the pooled results. Results The overall diagnostic sensitivity for monoclonal gammopathies was 92.6% (CI: 90.5-94.3%). Specifically, diagnostic sensitivity was 90.5% (86.2-93.6%) for MGUS; 100.0% (97.5-100.0%) for SMM; 90.2% (85.5-93.5%) for MM; 100.0% (93.2-100.0%) for WM; and 83.6% (71.7-91.1%) for AL amyloidosis. The diagnostic specificity of the assay was 76.5% (72.2-80.3%). The EXENT System identified an M-protein in more patients than serum protein electrophoresis (SPE): 665 (92.6%) vs 611 (85.1%). The positivity rate was 90.5% vs 88.1% in MGUS; 100% vs 92.8% in SMM; 90.2% vs 80.5% in MM; 100% vs 100% in WM; ","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"19 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203689","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-296 Sensitive and Rapid Homogeneous Immunoassay for the Detection of Buprenorphine and its Major Metabolites in Urine","authors":"Jie Liang, Soon Oh, Rajendra Singh, Thomas Houts, Robert O’Malley","doi":"10.1093/clinchem/hvaf086.683","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.683","url":null,"abstract":"Background Buprenorphine is a synthetic opioid derived from thebaine. It is structurally and pharmacologically similar to morphine, but is 20-30 times more potent. It is a partial agonist receptor modulator and has a longer duration of action relative to morphine due to its unusual slow rate of dissociation from its receptor. Buprenorphine produces a variety of symptoms including, but not limited to addiction, life-threatening respiratory depression, neonatal opioid withdrawal syndrome, severe hypotension. After administration in humans, buprenorphine is primarily metabolized through N-dealkylation to form norbuprenorphine. Both buprenorphine and norbuprenorphine undergo further metabolism via conjugation with D-glucuronic acid to form buprenorphine-glucuronide and norbuprenorphine-glucuronide. Pharmaceutical buprenorphine is a medication used to treat opioid use disorders (OUDs) and manage severe pain that necessitates an opioid analgesic when other treatments are insufficient. Furthermore, it has occasionally been used off-label (i.e., for purposes not approved by the FDA) via injection, including applications in perineural anesthesia and managing withdrawal in hospitalized patients dependent on heroin. In 2002, buprenorphine, including its salts, isomers and salts of isomers, became a Schedule III narcotic substance under the Controlled Substances Act for its potential for abuse and risk of dependence. ARK Diagnostics has developed the ARK Buprenorphine Assay to detect buprenorphine and its metabolites at a cutoff concentration of 5 ng/mL of buprenorphine with high cross-reactivity to its metabolites, norbuprenorphine, buprenorphine-glucuronide, and norbuprenorphine-glucuronide without additional treatment of glucuronidase. Methods The ARK Buprenorphine Assay is a liquid stable homogeneous enzyme immunoassay, consisting of two reagents, with a cutoff concentration of 5 ng/mL and semi-quantitative range up to 100 ng/mL. The performance of this assay was evaluated on the Beckman Coulter AU680 Automated Clinical Chemistry Analyzer. Precision, analytical recovery, specificity, Histogram Overlap Analysis of ± 40% controls and the cutoff, and method comparison with LC-MS/MS were evaluated. Results In semi-quantitative mode, total precision ranged from 4.0 to 8.0 % CV. Spiked recovery ranged from 94.0% to 103.4 % for the samples spanning 2.0 to 100.0 ng/mL. The major metabolites, norbuprenorphine, buprenorphine-glucuronide, and norbuprenorphine-glucuronide, showed approximate equivalences to the 5 ng/mL buprenorphine cutoff at 10.0 ng/mL (50.0 % cross-reactivity), 5.8 ng/mL (86.2 % cross-reactivity), and 8.5 ng/mL (58.8% cross-reactivity), respectively. Histogram overlap analysis showed no overlap between cutoff and control levels. Method correlation with LC-MS/MS using authentic urine samples showed an excellent agreement with specificity and sensitivity. Conclusion The ARK Buprenorphine Assay measures buprenorphine and its major metabolites, norbup","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"62 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145202930","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}