Journal of Mass Spectrometry and Advances in the Clinical Lab最新文献

{"title":"Sex-based estimation of biological variation in plasma-free amino acid concentrations among healthy adults","authors":"Müjgan Ercan ,&nbsp;Emiş Deniz Akbulut ,&nbsp;Ayşen Caniklioğlu ,&nbsp;Esra Fırat Oğuz ,&nbsp;Yakup Dülgeroğlu ,&nbsp;Esin Avcı ,&nbsp;Şerif Ercan","doi":"10.1016/j.jmsacl.2025.04.010","DOIUrl":"10.1016/j.jmsacl.2025.04.010","url":null,"abstract":"<div><h3>Introduction</h3><div>Free amino acid (FAA) analysis plays a crucial role in diagnosing and monitoring inborn errors of metabolism, assessing nutritional status, and identifying metabolic imbalances associated with various diseases. This study aimed to provide updated biological variation (BV) data to support the reliable clinical application of FAA concentrations in plasma samples, utilizing LC-MS/MS.</div></div><div><h3>Materials and methods</h3><div>Venous blood was collected from 22 healthy Turkish adults (9 men and 13 women) over approximately nine weeks. Plasma FAAs were measured in duplicate. BV estimates with 95 % confidence intervals were determined using nested ANOVA for the entire study group and sex-stratified subgroups, following analysis of outliers, normality, steady-state conditions, and variance homogeneity.</div></div><div><h3>Results</h3><div>Within-subject variation (CV_I) and between-subject variation (CV_G) estimates ranged from 9.5 % to 32.5 % and 8.6 % to 50.0 %, respectively. The estimated CV_I values for essential amino acids were significantly lower than those for non-essential amino acids (<em>P</em> = <em>0.03</em>). For most plasma FAAs, no significant differences in CV_I (except for alanine, arginine, glutamic acid, and threonine) or CV_G were observed between sexes. However, differences in the indices of individuality were noted between men and women for some plasma FAAs.</div></div><div><h3>Conclusions</h3><div>This Biological Variation Data Critical Appraisal Checklist-compliant study provides the first updated BV data for plasma FAAs. The significant variation observed in CV_I estimates is hypothesized to result from differences in the metabolic regulation of essential versus non-essential amino acids. The sex-stratified indices obtained in this study will aid in the appropriate application of population-based reference intervals for plasma FAA assessment.</div></div>","PeriodicalId":52406,"journal":{"name":"Journal of Mass Spectrometry and Advances in the Clinical Lab","volume":"37 ","pages":"Pages 1-8"},"PeriodicalIF":3.1,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899511","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":"Investigation of potential biomarkers for psoriasis in skin with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and ambient ionization mass spectrometry","authors":"Yi-Wen Hsu ,&nbsp;Hung Su ,&nbsp;Deng-Chyang Wu ,&nbsp;Chi-Wei Lee ,&nbsp;Sung-Jen Hung ,&nbsp;Jentaie Shiea","doi":"10.1016/j.jmsacl.2025.04.004","DOIUrl":"10.1016/j.jmsacl.2025.04.004","url":null,"abstract":"<div><h3>Background</h3><div>Psoriasis is a chronic inflammatory disease with an unclear etiology that affects skin, nails, and joints and often accompanies comorbidities. Recent studies indicate that alterations in metabolites within psoriatic lesions might be linked to inflammation. Studying bioactive lipid mediators or metabolites in skin inflammation and immunity might provide new potential biomarkers and therapeutic prediction factors.</div></div><div><h3>Methods</h3><div>Lipids and peptides in the scale extracts from psoriasis patients and healthy controls were characterized by thermal desorption-electrospray ionizationmass spectrometry and matrix-assisted laser desorption/ionization time-of-flightmass spectrometry, respectively. Principal component analysis (PCA) was then applied to these data to identify potential differences between psoriasis patients and healthy controls.</div></div><div><h3>Results</h3><div>Psoriatic plaques show reduced wax esters and triglycerides and a predominant increase in human neutrophil defensins (HNPs), compared to non-lesional sites of psoriatic patients and healthy control. Additionally, when medical treatments were administered to psoriasis patients, levels of HNPs were significantly reduced, suggesting that they may serve as potential biomarkers to evaluate therapeutic efficacy for psoriasis.</div></div><div><h3>Conclusion</h3><div>Two mass spectrometric techniques were used to rapidly and non-invasively identify and monitor potential biomarkers between psoriasis patients and healthy controls. However, PCA results only showed slight differences, and we intend to broaden the sample base in the future to increase the statistical power of the investigation.</div></div>","PeriodicalId":52406,"journal":{"name":"Journal of Mass Spectrometry and Advances in the Clinical Lab","volume":"36 ","pages":"Pages 52-62"},"PeriodicalIF":3.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859205","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":"Quantification of glucagon and oxyntomodulin by protein precipitation-immunoaffinity enrichment-LC-MS/MS","authors":"Jessica O. Becker ,&nbsp;Sara K. Shijo ,&nbsp;Huu-Hien Huynh ,&nbsp;Katrina L. Forrest ,&nbsp;Michael J. MacCoss ,&nbsp;Michelle A. Emrick ,&nbsp;Elisha Goonatilleke ,&nbsp;Andrew N. Hoofnagle","doi":"10.1016/j.jmsacl.2025.04.002","DOIUrl":"10.1016/j.jmsacl.2025.04.002","url":null,"abstract":"<div><h3>Introduction</h3><div>Glucagon and oxyntomodulin are peptide hormones differentially released from proglucagon that function in regulating blood glucose. Their overlapping amino acid sequences make the development of specific immunoassays difficult, but the specificity of liquid chromatography-tandem mass spectrometry can be used to distinguish the peptides. We aimed to develop a sensitive and specific mass spectrometric assay that uses non-proprietary reagents and normal-flow liquid chromatography in the simultaneous quantification of both analytes.</div></div><div><h3>Methods</h3><div>Bulk plasma proteins were precipitated in ethanol/ammonium hydroxide. Analytes were enriched using monoclonal antibodies generated in-house and analyzed using liquid chromatography-tandem mass spectrometry. A glucagon calibration material was sourced commercially and characterized for purity and concentration by high-performance liquid chromatography-ultraviolet detection and amino acid analysis. Single-point calibration was used to minimize between-day variability.</div></div><div><h3>Results</h3><div>The novel antibodies performed acceptably (peptide recovery 45–59 %). The assay was precise (&lt;13 %CV) and linear over the range of 1.3–14.7 pM and 1.1–13.7 pM for glucagon and oxyntomodulin, respectively. The glucagon calibration material concentration was determined to be 1.596 mg/g. Tube-type studies supported the use of protease inhibitor tubes at the time of blood draw. Patients with type 1 diabetes had lower concentrations of glucagon when maintained on an insulin pump, but not with injectable insulin.</div></div><div><h3>Conclusion</h3><div>We have validated a method with a highly detailed standard operating procedure. We have characterized calibration materials to help maintain accuracy and achieve between-day and between-laboratory harmonization. The assay will be beneficial in better understanding α-cell health and glycemic control in diabetes and other diseases.</div></div>","PeriodicalId":52406,"journal":{"name":"Journal of Mass Spectrometry and Advances in the Clinical Lab","volume":"36 ","pages":"Pages 37-45"},"PeriodicalIF":3.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143839104","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":"Validation of an LC-MS/MS method for urinary homovanillic and vanillylmandelic ACIDS and application to the diagnosis of neuroblastoma","authors":"Lucilla Rossi ,&nbsp;Yvette A.H. Matser ,&nbsp;Sebastiano Barco ,&nbsp;Alessia Cafaro ,&nbsp;Federica Pigliasco ,&nbsp;Margherita Biondi ,&nbsp;Fabrizio Mancin ,&nbsp;Maria van der Ham ,&nbsp;Monique G.M. de Sain-van der Velden ,&nbsp;Shifra Ash ,&nbsp;Maja Beck Popovic ,&nbsp;André B.P. van Kuilenburg ,&nbsp;Massimo Conte ,&nbsp;Alberto Garaventa ,&nbsp;Godelieve A.M. Tytgat ,&nbsp;Giuliana Cangemi","doi":"10.1016/j.jmsacl.2025.04.007","DOIUrl":"10.1016/j.jmsacl.2025.04.007","url":null,"abstract":"<div><h3>Background</h3><div>Urinary catecholamine metabolites are well-established biomarkers for neuroblastoma (NB). Homovanillic acid (HVA) and vanillylmandelic acid (VMA) are the most frequently measured metabolites within SIOPEN – Catecholamine Working Group laboratories. Here, we evaluated the performance of a new LC-MS/MS in vitro diagnostic (IVD) kit for HVA and VMA to facilitate inter-laboratory harmonization.</div></div><div><h3>Methods</h3><div>HVA and VMA and their deuterated internal standards were analyzed with a commercial method, on a ThermoFisher Quantiva LC-MS/MS. Validation was performed first using internal quality control and external quality assessment (IQC and EQA) samples. Next by clinical validation on 120 samples, previously tested by HPLC-ECD. Finally, 36 samples were exchanged between SIOPEN reference laboratories and analyzed by three methods.</div></div><div><h3>Results</h3><div>Using QCs and EQA the method was validated in a wide calibration range (4.61–830 µmol/L for HVA and 4.44–800 µmol/L for VMA). Intra-day CVs (<em>n</em> = 5) were 7 and 8 % for HVA and 5 and 6 % for VMA for QC low and QC high, respectively; Inter-day CV% were 7 and 3 % for HVA and 2 and 7 % for VMA at QC low and QC high, respectively. Its application to 120 clinical samples confirmed a high diagnostic accuracy. The inter-laboratory quality control assessment showed interchangeable results (<em>p =</em> 0,73 and <em>p =</em> 0.15 for HVA and VMA, respectively).</div></div><div><h3>Conclusion</h3><div>The LC-MS/MS IVD method could be considered a useful tool for clinical laboratories involved in the measurement of catecholamines, contributing to harmonization efforts.</div></div>","PeriodicalId":52406,"journal":{"name":"Journal of Mass Spectrometry and Advances in the Clinical Lab","volume":"36 ","pages":"Pages 73-81"},"PeriodicalIF":3.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869835","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":"Quantification of total sBCMA in human plasma by peptide-level immunocapture LC-MS/MS","authors":"Johanna Paris ,&nbsp;Alexandra Tavernier ,&nbsp;Sylvie Bethegnies,&nbsp;Sandrine Descloux,&nbsp;Olivier Fedeli","doi":"10.1016/j.jmsacl.2025.04.006","DOIUrl":"10.1016/j.jmsacl.2025.04.006","url":null,"abstract":"<div><h3>Background</h3><div>B-cell maturation antigen (BCMA) is a membrane protein that is overexpressed in multiple myeloma cells and can be targeted with biotherapeutic agents. BCMA is naturally shed by γ-secretase, leading to the formation of soluble BCMA (sBCMA), which circulates in the blood. sBCMA can affect the efficacy of BCMA-targeted therapies and act as a drug sink. Additionally, sBCMA can interfere with pharmacokinetic measurements when BCMA is directly targeted. Therefore, quantification of this biomarker during clinical trials is essential to assess the effective dose and understand pharmacokinetic results. When quantifying sBCMA using ligand binding assays or hybrid assays, the biotherapeutic can interfere with the capture of sBCMA, leading to an underestimation of its levels.</div></div><div><h3>Methods</h3><div>Samples were denatured, reduced, and alkylated prior to trypsin digestion. sBCMA peptide enrichment was performed using anti-peptide polyclonal antibodies. Reversed-phase chromatographic separation was conducted on a biocompatible C18 column with an analysis time of sixteen minutes per sample. The SCIEX QTRAP 5500 mass spectrometer operated in multiple reaction monitoring mode. The calibration curve was prepared by spiking recombinant sBCMA into monkey plasma.</div></div><div><h3>Results</h3><div>The parallelism between the authentic and surrogate matrices, as well as between the endogenous and recombinant proteins, was validated. Comparisons were made between protein and peptide level hybrid assays, with the peptide level approach effectively removing the interference of the biotherapeutic. Additionally, the peptide level immunocapture LC-MS/MS demonstrated ligand tolerance.</div></div><div><h3>Conclusion</h3><div>The peptide level immunocapture LC-MS/MS analysis eliminated the interference of anti-BCMA biotherapeutics, allowing for the quantification of total sBCMA in clinical samples while achieving a LLOQ of 10 ng/mL.</div></div>","PeriodicalId":52406,"journal":{"name":"Journal of Mass Spectrometry and Advances in the Clinical Lab","volume":"36 ","pages":"Pages 46-51"},"PeriodicalIF":3.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859204","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":"A rapid method for determination of rosuvastatin in blood plasma with supported liquid extraction","authors":"Tjaša Dermota ,&nbsp;Mojca Božič Mijovski ,&nbsp;Jurij Trontelj","doi":"10.1016/j.jmsacl.2025.04.003","DOIUrl":"10.1016/j.jmsacl.2025.04.003","url":null,"abstract":"<div><h3>Introduction</h3><div>Accurate measurement of rosuvastatin in plasma is critical for effective patient management and treatment monitoring following myocardial infarction (MI). Expensive solid-phase extraction (SPE) and time-consuming liquid–liquid extraction (LLE) have been established for quantifying rosuvastatin. Supported liquid extraction (SLE) could offer a rapid, cost-effective alternative.</div></div><div><h3>Objectives</h3><div>This study aimed to develop and validate a rapid, cost-effective, accurate, and precise method for quantifying rosuvastatin in high-dose plasma samples from patients following MI.</div></div><div><h3>Methods</h3><div>Rosuvastatin was extracted from EDTA plasma using SLE and quantified with LC-MS/MS with positive electrospray ionization. The method was validated according to ICH M10 guidelines, focusing on selectivity, matrix effect, accuracy, precision, linearity, and carryover. Rosuvastatin-D6 was used as an internal standard. Additionally, thirty plasma samples from patients on high-dose rosuvastatin therapy (20 or 40 mg/day) following MI were analyzed by both LLE and SLE methods and compared.</div></div><div><h3>Results</h3><div>The method was successfully validated, demonstrating linearity across a range of 0.1 ng/mL to 50 ng/mL. Compared to the LLE method, SLE achieved superior extraction recovery (96.3 % vs. 60 %) and precision (RSD: 11.9 % vs. 13.6 %) at 0.3 ng/mL rosuvastatin, with a lower absolute matrix effect (12.7 % vs. −36.7 %). Accuracy was comparable (109.3 % vs. 92.8 %). Although SLE involves higher initial costs, it significantly enhances throughput, reduces solvent usage, and minimizes contamination and equipment wear.</div></div><div><h3>Conclusion</h3><div>This study validates SLE as a superior method for quantifying rosuvastatin in plasma, outperforming LLE in recovery, reproducibility, and automation. SLE offers greater accuracy and reliability, making it ideal for high-throughput applications.</div></div>","PeriodicalId":52406,"journal":{"name":"Journal of Mass Spectrometry and Advances in the Clinical Lab","volume":"36 ","pages":"Pages 29-36"},"PeriodicalIF":3.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820388","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":"Development of an isotope dilution gas chromatography − mass spectrometry candidate reference measurement procedure for glucose in human serum","authors":"Komal Dahya ,&nbsp;Heather C. Kuiper ,&nbsp;Sarah W. Kingsley ,&nbsp;Uliana Danilenko ,&nbsp;Hubert W. Vesper","doi":"10.1016/j.jmsacl.2025.04.005","DOIUrl":"10.1016/j.jmsacl.2025.04.005","url":null,"abstract":"<div><h3>Introduction</h3><div>Diabetes is the seventh leading cause of death in the United States, impacting over 37 million people. Accurate glucose measurements are critical for effective diabetes management. A reliable candidate reference measurement procedure (cRMP) for assessing the analytical performance of glucose tests performed in patient care is essential for ensuring measurement accuracy.</div></div><div><h3>Methods</h3><div>We have developed a gas chromatography-mass spectrometry (GC–MS)-based cRMP for glucose in human serum. In this procedure, glucose is measured as the aldononitrile acetate derivative and quantitated using a ¹³C₆-glucose internal standard.</div></div><div><h3>Results</h3><div>Analytical selectivity was achieved through chromatographic separation and monitoring the quantitation ion/confirmation ion ratios in samples. With bias ranging from −0.79 % to 0.67 % for eight levels of serum-based certified reference materials from the National Institute of Standards and Technology (NIST) and Laboratoire national de métrologie et d’essais (LNE) and total CVs of 1.11 %, 0.68 % and 0.74 % at the low, medium, and high glucose concentration levels, respectively, the cRMP provided excellent accuracy and precision. The calibration curve was linear throughout the 13.51–378.21 mg/dL [0.75–21 mmol/L] measurement range (R² = 0.9999), with a mean slope of 270.73 (95 % CI, 270.19 to 271.27) and an intercept of 0.021 (95 % CI, −0.157 to 0.199). The limit of detection was 0.25 mg/dL (0.014 mmol/L) and the limit of quantitation was 0.83 mg/dL (0.046 mmol/L).</div></div><div><h3>Conclusion</h3><div>The described GC–MS method, with metrological traceability to the International System of Units (SI), provides highly accurate and precise measurements of glucose in human serum.</div></div>","PeriodicalId":52406,"journal":{"name":"Journal of Mass Spectrometry and Advances in the Clinical Lab","volume":"36 ","pages":"Pages 63-72"},"PeriodicalIF":3.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865047","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":"Development and validation of a highly-sensitive, quantitative LC-MS/MS assay to evaluate plasma oxytocin","authors":"E. Grifnée ,&nbsp;A. Mackowiak ,&nbsp;J. Demeuse ,&nbsp;M. Schoumacher ,&nbsp;L. Huyghebaert ,&nbsp;W. Determe ,&nbsp;T. Dubrowski ,&nbsp;P. Massonnet ,&nbsp;S. Peeters ,&nbsp;G. Scantamburlo ,&nbsp;E. Cavalier ,&nbsp;C.Le Goff","doi":"10.1016/j.jmsacl.2025.02.002","DOIUrl":"10.1016/j.jmsacl.2025.02.002","url":null,"abstract":"<div><h3>Introduction</h3><div>Oxytocin is a 9-amino acid peptide that serves as neuromodulator in the human central nervous system. This peptide is implicated in the regulation of diverse behaviors and plays a significant role in positive social interaction. Currently, oxytocin levels are measured using immunoassays. However, these methods have several limitations that can lead to false results and erroneous interpretation. Given the remarkably low endogenous level of oxytocin in human plasma (low ng/L levels), we developed and rigorously validated a novel and highly sensitive LC-MS/MS method for oxytocin quantification in plasma.</div></div><div><h3>Methods</h3><div>Oxytocin was initially extracted using solid-phase extraction with an Oasis HLB 30 mg plate and then subjected to LC-MS/MS analysis. PBS-0.1 % BSA served as surrogate matrix for the preparation of validation samples and the calibration curve, ensuring no endogenous interference. The validation design followed the Clinical Laboratory Standards Institute guidelines. Precision, accuracy, and measurement uncertainty were determined using single-nested analysis of variance and e.noval software.</div></div><div><h3>Results</h3><div>A lower limit of quantification of 1 ng/L was achieved. The method was validated for oxytocin concentrations ranging from 1 ng/L to 75 ng/L, with precision (coefficient of variation) below 10 %, accuracy ranging from 94 % to 108 %, and measurement uncertainty below 15 %.</div></div><div><h3>Conclusion</h3><div>In this work, we developed and validated a highly sensitive LC-MS/MS method for the quantification of oxytocin in plasma. Our novel methodology is well-suited for clinical applications.</div></div>","PeriodicalId":52406,"journal":{"name":"Journal of Mass Spectrometry and Advances in the Clinical Lab","volume":"36 ","pages":"Pages 19-28"},"PeriodicalIF":3.1,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Barcoded labels as potential source of zinc contamination in trace metal testing","authors":"Difei Sun ,&nbsp;Donna Sealy ,&nbsp;Dorothy Truong ,&nbsp;Danijela Konforte","doi":"10.1016/j.jmsacl.2025.02.003","DOIUrl":"10.1016/j.jmsacl.2025.02.003","url":null,"abstract":"","PeriodicalId":52406,"journal":{"name":"Journal of Mass Spectrometry and Advances in the Clinical Lab","volume":"36 ","pages":"Pages 9-10"},"PeriodicalIF":3.1,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MRM-based LC-MS method for accurate C-peptide quantitation","authors":"Will Grothoff,&nbsp;Ivan Khodakivskyi,&nbsp;Aleks Shin,&nbsp;Randie Little,&nbsp;Shawn Connolly,&nbsp;Kuanysh Kabytaev","doi":"10.1016/j.jmsacl.2025.02.001","DOIUrl":"10.1016/j.jmsacl.2025.02.001","url":null,"abstract":"<div><h3>Introduction</h3><div>C-peptide secretion mirrors beta-cell function and has emerged as a valuable clinical biomarker for diabetes mellitus. C-peptide measurements can provide estimates of insulin secretory capacity, aiding in clinical decision-making and differentiation between diabetes types. Unfortunately, C-peptide assays are still not standardized, which may limit their practical clinical use. We have developed an MRM-based LC-MS method that demonstrated accuracy close to our reference method.</div></div><div><h3>Objective</h3><div>To develop and validate a mass spectrometry method for accurate quantitation of C-peptide.</div></div><div><h3>Method</h3><div>A serum sample was spiked with isotope-labeled C-peptide as a standard. The enrichment process involved protein precipitation with methanol, solid-phase extraction, and anion exchange for C-peptide enrichment followed by Glu-C digestion. The peptide LGGGPGAGSLQPLALE was quantitated using MRM in positive ion mode. The calibration process includes C-peptide CRM material to ensure a complete traceability chain for the measurement.</div></div><div><h3>Results</h3><div>The assay exhibited linearity across a wide range of C-peptide concentrations and a limit of quantitation of 0.058 nmol/L. The inter-day imprecision was less than 9.6 % CV, and the intra-day imprecision was less than 8.9 % CV. Spiking with bilirubin, triglycerides, and hemoglobin demonstrated no interference, except for triglycerides at very high levels. The method exhibited a strong correlation to the C-peptide reference method (r2 = 0.95).</div></div><div><h3>Conclusion</h3><div>The developed mass spectrometry method has demonstrated accurate results in C-peptide quantitation and can serve as a supplemental method to the existing C-peptide reference method. This ensures sustained stability over time and ultimately refines the existing reference system.</div></div>","PeriodicalId":52406,"journal":{"name":"Journal of Mass Spectrometry and Advances in the Clinical Lab","volume":"36 ","pages":"Pages 1-8"},"PeriodicalIF":3.1,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}