Clinical biochemistry最新文献

{"title":"Phenotyping and genotyping for the dihydropyrimidine dehydrogenase test in Italy: a precise diagnostic strategy to detect rare variants and improve drug administration","authors":"Maria Lucia Tommolini ,&nbsp;Mirco Zucchelli ,&nbsp;Alberto Frisco ,&nbsp;Rossella Ferrante ,&nbsp;Beatrice Dufrusine ,&nbsp;Claudia Palmarini ,&nbsp;Luca Natale ,&nbsp;Patrizia Ballerini ,&nbsp;Liborio Stuppia ,&nbsp;Luca Federici ,&nbsp;Damiana Pieragostino ,&nbsp;Ilaria Cicalini","doi":"10.1016/j.clinbiochem.2025.111010","DOIUrl":"10.1016/j.clinbiochem.2025.111010","url":null,"abstract":"<div><h3>Introduction</h3><div>Dihydropyrimidine dehydrogenase (DPD) is the enzyme implicated in the catabolism of the fluoropyrimidines (FP), a class of chemotherapeutics used to treat many cancers. The <em>DPYD</em> gene is known to have a huge number of variants potentially associated with DPD deficiency. Therefore, phenotypic and genotypic characterization of DPD is fundamental for cancer patients before undergoing treatment with FP. The AIOM (Italian Association of Medical Oncology) requires genetic analysis, with the purpose to identify a panel of 5 single nucleotide polymorphisms associated with 5-fluorouracil (5-FU)-induced toxicity, while the biochemical test, which measures uracil levels to predict the residual activity of DPD, is only recommended and not mandatory.</div></div><div><h3>Methods</h3><div>Single nucleotide polymorphisms were analyzed by real-time polymerase chain reaction (PCR) from peripheral blood. Uracil and dihydrouracil were quantified using an ultra-performance liquid chromatography/tandem mass spectrometry system in plasma obtained from patients before 5-FU treatment. Sanger sequencing was performed for the <em>DPYD</em> gene.</div></div><div><h3>Results</h3><div>Here, we describe the case of a 70-year-old Caucasian male patient with pancreatic cancer for whom real-time PCR highlighted a heterozygous pathogenic variant c.1905 + 1G &gt; A associated with a 50 % reduction of DPD enzymatic activity. This finding was not confirmed by the biochemical test which revealed a complete absence of DPD activity. By performing Sanger sequencing, we highlighted the concomitant presence of a likely pathogenic variant c.2622 + 1G &gt; A, not compatible with the administration of 5-FU.</div></div><div><h3>Conclusion</h3><div>Thus far, guidelines provide a limited panel for the identification of pathogenic or likely pathogenic variants of the <em>DPYD</em> gene, therefore we encourage the mandatory use of biochemical tests as a precise diagnostic strategy to detect rare variants and improve drug administration.</div></div>","PeriodicalId":10172,"journal":{"name":"Clinical biochemistry","volume":"140 ","pages":"Article 111010"},"PeriodicalIF":2.1,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145052220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical implementation and outcome evaluation of dihydropyrimidine dehydrogenase (DPYD) pharmacogenomic testing for fluoropyrimidine dosing in a Canadian Provincial Healthcare center","authors":"Fang Wu ,&nbsp;Song Lu ,&nbsp;Dan Zhang ,&nbsp;Nelly Abdelfatah ,&nbsp;Vijayananda Kundapur ,&nbsp;Fergall Magee ,&nbsp;Yanwei Xi","doi":"10.1016/j.clinbiochem.2025.111008","DOIUrl":"10.1016/j.clinbiochem.2025.111008","url":null,"abstract":"<div><h3>Background</h3><div>5-Fluorouracil (5-FU) and its pro-drug, capecitabine, are widely used to treat solid tumors. Patients with dihydropyrimidine dehydrogenase (<em>DPYD</em>) deficiency are at increased risk for severe treatment-related toxicity. This study reported the implementation of <em>DPYD</em> genotyping in clinical practice and assessed the impact of genotype-guided dosing on clinical outcomes.</div></div><div><h3>Methods</h3><div>An in-house pharmacogenomic testing using the Elucigene <em>DPYD</em> genotyping kit (Yourgene Health, UK) was established to detect the four most common clinically actionable <em>DPYD</em> alleles, including <em>*2A, *13, HapB3</em> and c.2846A&gt;T (rs67376798). Six months post-implementation, a retrospective chart review assessed genotype results, chemotherapy regimens, dose modifications, adverse events related to 5-FU or capecitabine, and demographics. Data were de-identified for analysis.</div></div><div><h3>Results</h3><div>Analytical validation of the <em>DPYD</em> assay showed 100 % sensitivity, specificity, accuracy, reproducibility, and repeatability. The genotyping workflow was successfully integrated into clinical practice, with a rapid turnaround time to meet oncology treatment planning. From July to December 2024, 299 patients underwent <em>DPYD</em> testing; variants were identified in 22 patients, including 20 patients (6.7 %) with clinically significant variants conferring a reduced DPD function and 2 patients with a variant (c.483 + 18G&gt;A; rs56276561) that retains normal DPD function. Among those variants, <em>HapB3</em> (n = 18) was the most frequent one, characterized by c.1129-5923C&gt;G and c.1236G&gt;A <em>(</em>rs75017182, rs56038477) co-occurring with c.483 + 18G&gt;A (rs56276561). Of 233 patients receiving 5-FU-based chemotherapy, 13 were variant carriers. Genotype-guided dosing allowed early dose optimization, and all carriers completed at least three treatment cycles, with one severe adverse event attributed to oxaliplatin rather than 5-FU.</div></div><div><h3>Conclusions</h3><div>This study reported the integration of <em>DPYD</em> pharmacogenomic testing into oncology care and evaluated the post-implementation clinical outcomes, highlighting the critical role of pharmacogenomic testing in optimizing cancer treatment and improving patient safety.</div></div>","PeriodicalId":10172,"journal":{"name":"Clinical biochemistry","volume":"140 ","pages":"Article 111008"},"PeriodicalIF":2.1,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145004771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HER2 gene mutations and matrix biomarkers in breast cancer","authors":"Leyla Karimova ,&nbsp;Gulnara Azizova ,&nbsp;Ilaha Shahverdiyeva","doi":"10.1016/j.clinbiochem.2025.111007","DOIUrl":"10.1016/j.clinbiochem.2025.111007","url":null,"abstract":"<div><h3>Objective</h3><div>Breast cancer (BC) remains a leading cause of morbidity and mortality among women globally. This study aims to investigate <em>HER2</em> mutations in HER2-negative BC and evaluate the diagnostic potential of matrix metalloproteinases (MMP-7, MMP-9) and CYR61 as serum biomarkers.</div></div><div><h3>Material and methods</h3><div>The study involved 74 women diagnosed with BC (HER2-positive: n = 33; HER2-negative: n = 33; triple negative: n = 8) and 25 healthy controls. <em>HER2</em> gene mutations were analyzed using the “AmoyDx HER2 Mutation Detection” kit. Serum MMP-7, MMP-9, and CYR61 levels were quantified using Bio-Techne kits (R&amp;D Systems) using the Quantikine ELISA method.</div></div><div><h3>Results</h3><div>The study found no mutations (A775_G776insYVMA, M774_A775insAYVM, G776 &gt; VC, G776R, G776C, P780_Y781insGSP, V777L, L755P) in exons 18 and 20 of the <em>HER2</em> gene in HER2 negative BC patients.</div><div>MMP-9 serum levels were significantly reduced in BC patients compared to the control group (p &lt; 0.001). However, MMP-7 levels showed no significant variation when compared to healthy women (p = 0.464). CYR61 exhibited high diagnostic accuracy (AUC = 0.95), supporting its potential as a reliable biomarker.</div></div><div><h3>Conclusion</h3><div>The reduction in serum MMP-9 levels correlates with ongoing tissue processes, primarily due to increased consumption in the extracellular matrix. CYR61 overexpression is observed across all breast cancer subtypes, independent of HER2 activity, suggesting its significant potential for use in BC diagnosis and treatment.</div></div>","PeriodicalId":10172,"journal":{"name":"Clinical biochemistry","volume":"140 ","pages":"Article 111007"},"PeriodicalIF":2.1,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144997110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elevated level of platelet factor 4 in follicular fluid is associated with polycystic ovary syndrome","authors":"Wenqi Wang ,&nbsp;Guangxi Wang ,&nbsp;Xiaoming Niu ,&nbsp;Zhonglan Li ,&nbsp;Mingfu Zhang ,&nbsp;Zhenchao Xu ,&nbsp;Tou Liu","doi":"10.1016/j.clinbiochem.2025.111009","DOIUrl":"10.1016/j.clinbiochem.2025.111009","url":null,"abstract":"<div><h3>Objective</h3><div>This present study aimed to measure platelet factor 4 (PF4) protein level in follicular fluid of patients with polycystic ovary syndrome (PCOS) and analyzed the correlation between follicular PF4 level with clinical characteristics.</div></div><div><h3>Methods</h3><div>Sixty-seven women (36 PCOS patients vs. 31 non-PCOS women) were enrolled in the study. Follicular fluid PF4 level was analyzed by enzyme-linked immunosorbent assay.</div></div><div><h3>Results</h3><div>The level of PF4 was significantly higher in follicular fluid of patients with PCOS than that of non-PCOS controls (50.5 (95 % CI: 42.8 to 115.86) ng/ml vs. 37.42 (95 % CI: 23.01 to 49.69) ng/ml, <em>p</em> &lt; 0.001). Correlation analysis showed that the level of PF4 was positively related with serum anti-Mullerian hormone (r = 0.3809, <em>p</em> = 0.0015), serum testosterone (r = 0.3629, <em>p</em> = 0.0025), antral follicle count (r = 0.5544, <em>p</em> &lt; 0.0001), and number of oocytes retrieved (r = 0.3799, <em>p</em> = 0.0018) in all patients. The area under the curve of PF4 level in follicular fluid to predict PCOS was 0.723 (95 % CI: 0.600 to 0.847).</div></div><div><h3>Conclusions</h3><div>Our study demonstrated that the PF4 level was higher in the follicular fluid of patients with PCOS and was associated with key features of PCOS, suggesting that PF4 may play a role in the pathogenesis of PCOS.</div></div>","PeriodicalId":10172,"journal":{"name":"Clinical biochemistry","volume":"140 ","pages":"Article 111009"},"PeriodicalIF":2.1,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144997109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Method choice for investigation of macrotroponin interference with the Siemens Atellica high sensitivity troponin I assay","authors":"Amir Karin,&nbsp;Catherine Cheng","doi":"10.1016/j.clinbiochem.2025.111004","DOIUrl":"10.1016/j.clinbiochem.2025.111004","url":null,"abstract":"<div><h3>Objectives</h3><div>Macrotroponin refers to circulating immunoglobulin-bound cardiac troponin species that may elevate troponin results in patients with or without myocardial injury, causing diagnostic confusion. Clinical laboratories have been recommended to provide a service for troponin interference investigation. We evaluated the applicability of a Protein A/G IgG-depletion procedure as well as polyethylene glycol (PEG) precipitation for detecting macrotroponin interference with the Siemens Atellica troponin I (TnIH) assay.</div></div><div><h3>Methods</h3><div>Troponin I, IgG, and albumin (internal standard) were measured (Atellica) on the neat and treated plasma to calculate recovery. Reference samples with TnIH ranging from &lt; 1x to &gt; 1000x times the 99th percentile were selected to verify expected recovery. To minimize likelihood of macrotroponin in the reference group, samples with elevated results were only included if recent acute changes in TnIH was documented. 40 samples were used for the IgG-depletion method and 20 for PEG precipitation. 25 samples from patients with unexplained elevation in TnIH were assessed by IgG-depletion.</div></div><div><h3>Results</h3><div>38 of 40 reference group recoveries exceeded 70 % (median 91 %, IQR 15 %, max 129 %) in the IgG-depletion group consistent with literature on other assays. Specimens from patients with incongruent clinical picture had IgG-depletion recovery median of 11 % (IQR 14 %, max 37 %). PEG-precipitation showed large variation (median 103 %, IQR 89 %, max 227 %).</div></div><div><h3>Conclusions</h3><div>IgG depletion using Protein A/G can reliably establish IgG-mediated interference with Atellica TnIH. PEG precipitation results are difficult to interpret likely due to matrix effects, especially at values closer to the 99th percentile.</div></div>","PeriodicalId":10172,"journal":{"name":"Clinical biochemistry","volume":"140 ","pages":"Article 111004"},"PeriodicalIF":2.1,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144999884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Circulating free PSA in breast cancer patients: is it a reliable biomarker?","authors":"Vanessa Susini ,&nbsp;Maria Franzini ,&nbsp;Silvia Ursino ,&nbsp;Maria Ghilardi ,&nbsp;Riccardo Morganti ,&nbsp;Cristian Scatena ,&nbsp;Irene Bianco ,&nbsp;Alessandro Mazzoni ,&nbsp;Matteo Ghilli","doi":"10.1016/j.clinbiochem.2025.111006","DOIUrl":"10.1016/j.clinbiochem.2025.111006","url":null,"abstract":"<div><h3>Introduction</h3><div>Prostate-specific antigen (PSA), a serine protease primarily expressed in the prostate, has also been detected in hormonally regulated female tissues, including the breast. Some studies suggest a correlation between increased levels of circulating free PSA (fPSA) and breast cancer, but its role remains debated. This study aimed to evaluate this association while minimizing hormonal confounding factors.</div></div><div><h3>Methods</h3><div>A total of 82 breast cancer patients (aged 35–86 years) and 31 healthy premenopausal women (aged 18–58 years) were enrolled. Patients had a primary breast cancer diagnosis with no other malignancies and had not undergone preoperative chemotherapy or radiotherapy. Participants with hormonal conditions affecting PSA expression were excluded. fPSA levels were measured using an improved VIDAS® fPSA immunoassay with enhanced analytical sensitivity.</div></div><div><h3>Results</h3><div>Despite the increased sensitivity of the modified assay, fPSA was undetectable in all plasma samples. This may be due to the exclusion of participants with hormonal imbalances who might exhibit higher PSA expression.</div></div><div><h3>Conclusions</h3><div>The absence of androgen receptor (AR)-positive triple-negative breast cancer (TNBC) patients in this cohort further supports the role of androgens in PSA regulation. These findings suggest that fPSA may not be a reliable circulating biomarker for breast cancer. However, a key limitation is the lack of fPSA assessment within breast cancer tissue. Future studies should investigate its expression in tumors, particularly in AR-positive TNBC, and evaluate circulating fPSA and testosterone levels as potential biomarkers of tumor androgenic activity.</div></div>","PeriodicalId":10172,"journal":{"name":"Clinical biochemistry","volume":"140 ","pages":"Article 111006"},"PeriodicalIF":2.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144989191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How effective is serum FGL1 measurement in assessing disease activity: A cross-sectional study in rheumatoid arthritis","authors":"Mesut Ates ,&nbsp;Merve Ates ,&nbsp;Mujgan Gurler ,&nbsp;Murat Tasci ,&nbsp;Ozgur Mehmet Yis","doi":"10.1016/j.clinbiochem.2025.111005","DOIUrl":"10.1016/j.clinbiochem.2025.111005","url":null,"abstract":"<div><h3>Introduction</h3><div>In rheumatoid arthritis, which is an autoimmune inflammatory disease with multisystemic involvement, especially the joints, tracking disease activity is quite valuable in order to improve the quality of life of patients and to develop individualized treatment strategies. In this study, we evaluated the role of Fibrinogen-Like Protein 1 (FGL1), which has recently been shown to be associated with various rheumatological and autoimmune diseases, in disease diagnosis and activity in rheumatoid arthritis (RA).</div></div><div><h3>Material and Methods</h3><div>In this prospective study consisting of 108 RA patients divided into two groups as low disease activity-remission group (LDA) and moderate-high disease activity group (MHA) according to the Disease Activity Score 28-C-reactive protein score and 56 controls, serum FGL1 level was measured by Enzyme Linked ImmunoSorbent Assay (ELISA).</div></div><div><h3>Results</h3><div>Serum FGL1 level was found to be statistically significantly higher in RA patients compared to the control group, and in the MHA group compared to the LDA group. The mean FGL1 level was determined as 805.37 ng/ml in the LDA group, 1055.5 ng/ml in the MHA group and 652.31 ng/ml in the control group (p &lt; 0.001). There was a positive correlation between FGL1 level and CRP, Erythrocyte Sedimentation Rate (ESR), CRP/Albumin levels.</div></div><div><h3>Conclusions</h3><div>Increased serum FGL1 levels were found to increase the likelihood of identifying patients with moderate-to-high disease activity RA. FGL1 is also effective in evaluating disease activity when used together with other inflammation markers, especially CRP/Albumin.</div></div>","PeriodicalId":10172,"journal":{"name":"Clinical biochemistry","volume":"140 ","pages":"Article 111005"},"PeriodicalIF":2.1,"publicationDate":"2025-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Minimizing high sensitivity troponin T delta variation at low concentration using BD Barricor blood collection tube","authors":"Albert K.Y. Tsui ,&nbsp;Jialin Qiu ,&nbsp;Isolde Seiden-Long ,&nbsp;George Cembrowski","doi":"10.1016/j.clinbiochem.2025.111003","DOIUrl":"10.1016/j.clinbiochem.2025.111003","url":null,"abstract":"<div><h3>Objective</h3><div>Reproducible low troponin concentrations from high-sensitivity troponin (hs-cTn) assays are paramount to accurate risk determination in the accelerated diagnostic pathway. Total variation consists of pre-analytical, analytical and biological components. While analytical and biological variations cannot be readily modifiable, minimizing pre-analytical variation is desirable and potentially attainable. The BD Barricor collection tube has previously been demonstrated to reduce pre-analytical variation in test results. The goal of the study is to determine whether BD Barricor tubes provide more reproducible hs-cTnT results compared to plasma separator tubes (PST) at concentrations ≤ 20 ng/L.</div></div><div><h3>Methods</h3><div>Paired intra-patient hs-cTnT results collected less than 1 h apart in the emergency department were retrospectively analyzed from nine urban hospitals which primarily use either PST (n = 336 pairs) or Barricor (n = 327 pairs) collection tubes for troponin. Total variation of the replicated measurements was calculated for hs-cTnT ≤ 20 ng/L. The numbers of paired intra-patient samples were grouped based on decisive absolute delta thresholds as indicated by the European Society of Cardiology 0/1 h algorithm; delta &lt; 3 ng/L, 3–4 ng/L, ≥5 ng/L.</div></div><div><h3>Results</h3><div>The total testing variation for hs-cTnT collected in PST is 14.8 % while Barricor is 8.6 % for hs-cTnT ≤ 20 ng/L. The proportion of delta values &lt; 3 ng/L between the intra-patient replicates is 80.4 % (95 % CI: 75.7–84.5 %) in PST compared to 95.4 % (95 % CI: 92.5–97.4 %) in Barricor (p &lt; 0.001). Median time for serial sampling in PST is 41 min (IQR:18–53) and Barricor is 45 min (IQR 23–54).</div></div><div><h3>Conclusion</h3><div>The use of Barricor tubes demonstrated reproducible and less variable hs-cTnT replicates at concentration ≤ 20 ng/L when compared to a hospital that does not use Barricor tubes.</div></div>","PeriodicalId":10172,"journal":{"name":"Clinical biochemistry","volume":"140 ","pages":"Article 111003"},"PeriodicalIF":2.1,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of capillary dried blood spot and capillary microtubes with venous immunoglobulin G levels for routine diagnostics","authors":"S.L. Boland ,&nbsp;M.J.H. Doeleman ,&nbsp;L.G.E. Hofstee ,&nbsp;L. Soels ,&nbsp;T.S.Q. Visser ,&nbsp;S. de Roock ,&nbsp;D. Hamann ,&nbsp;J.M. van Montfrans ,&nbsp;W.M. Tiel Groenestege","doi":"10.1016/j.clinbiochem.2025.110996","DOIUrl":"10.1016/j.clinbiochem.2025.110996","url":null,"abstract":"<div><h3>Background and aims</h3><div>Patients with primary antibody deficiencies receiving immunoglobulin replacement therapy require frequent monitoring of immunoglobulin G (IgG) levels. Capillary IgG measurements from dried blood spots (DBS) or microtubes offer several advantages over samples obtained by venipuncture, including facilitating remote self-sampling. However, the validity of this alternative method is still unknown. We evaluated the comparability of IgG levels measured in venous samples with capillary blood samples collected on DBS cards and in microtubes.</div></div><div><h3>Methods</h3><div>Paired venous and capillary finger-stick DBS and microtube samples were collected from 100 patients. IgG was extracted from DBS with phosphate buffered saline and measured with a Siemens Atellica CH. For method comparison we performed Deming regression analysis. Absolute mean bias and limits of agreement were calculated with Bland-Altman analysis. The method comparison followed the Clinical Laboratory Improvement Amendments’ (CLIA) recommended approach, but stricter limits proposed by the EFLM were applied. Relative mean differences were compared to a 10.9 % total allowable error (TEa).</div></div><div><h3>Results</h3><div>Method comparison of venous versus capillary DBS samples resulted in an R of 0.77. Mean bias was 0.23 g/L with limits of agreement of −4.06 g/L to 4.53 g/L. Method comparison of venous versus capillary microtube samples resulted in an R of 1.00. Mean bias was −0.11 g/L with −0.67 g/L to 0.46 g/L limits of agreement. Relative mean differences were 2.2 % for DBS sampling and −0.6 % for capillary sampling, both fall within 10.9 % TEa and CLIA criteria.</div></div><div><h3>Conclusion</h3><div>IgG measurements from DBS demonstrated insufficient correlation and excessively broad limits of agreement, making it unsuitable for accurately determining IgG levels. This result hampers implementation of DBS in routine diagnostics. Conversely, capillary microtube samples demonstrated a strong correlation and narrow limits of agreement, which makes them a viable alternative to venipuncture.</div></div>","PeriodicalId":10172,"journal":{"name":"Clinical biochemistry","volume":"140 ","pages":"Article 110996"},"PeriodicalIF":2.1,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An improved and economical LLE-LC/MS method for quantifying phosphatidylethanol: Identification and separation of isotopic cross-talk in clinical alcohol testing","authors":"Naga Veera Yerra,&nbsp;Christopher Pini,&nbsp;Carlos Cordon-Cardo,&nbsp;Damodara Rao Mendu","doi":"10.1016/j.clinbiochem.2025.110994","DOIUrl":"10.1016/j.clinbiochem.2025.110994","url":null,"abstract":"<div><h3>Objective</h3><div>Phosphatidylethanol (PEth) is a group of phospholipids formed in the presence of ethanol on the red blood cell membrane. Due to their stability in blood for 3–4 weeks, they have become reliable direct biomarkers for long-term monitoring of alcohol use. This study aimed to develop and validate a robust, high-throughput liquid chromatography and tandem mass spectrometry (LC-MS/MS) method for the routine clinical quantification of the two most common PEth homologues, PEth 16:0/18:1 (POPEth) and PEth 16:0/18:2 (PLPEth), while addressing common analytical challenges.</div></div><div><h3>Methods</h3><div>An established quantification method employing liquid–liquid extraction was used with optimized LC-MS/MS parameters. The method was validated for correlation studies, precision, analytical measurement range, analytical sensitivity, analytical specificity, carryover, dilution linearity, stability, matrix effect and extraction recovery, with specific attention to eliminating isotopic cross-talk and chromatographic interferences. A method comparison was performed using specimens analyzed by an external reference laboratory.</div></div><div><h3>Results</h3><div>The method demonstrated excellent linearity for both POPEth and PLPEth across the analytical measurement range (10–2000 ng/mL), with correlation coefficients (r²) of 0.99. Intra- and inter-assay precision values were within ± 10 % coefficient of variation. Recovery yields ranged from 78-85 %. The optimized method resolved isotopic cross-talk and exhibited no carryover. Comparison with an external laboratory showed strong correlation for both homologues (slopes of 0.979 and 1.049; r² = 0.99).</div></div><div><h3>Conclusion</h3><div>We developed and validated a sensitive and specific LC-MS/MS method for the quantification of POPEth and PLPEth. The assay provides improved recovery, eliminates isotopic cross-talk, shows no carryover, and is suitable for high-throughput clinical laboratories. This method enables reliable and cost-effective monitoring of alcohol use in routine clinical practice.</div></div>","PeriodicalId":10172,"journal":{"name":"Clinical biochemistry","volume":"139 ","pages":"Article 110994"},"PeriodicalIF":2.1,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144892002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}