{"title":"Risk vs Prevalence: Weighing Routine DYPD Variant Testing Prior to Fluoropyrimidine-Based Chemotherapy.","authors":"Nicholas E Larkey,Mark R Girton","doi":"10.1093/clinchem/hvaf089","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf089","url":null,"abstract":"","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"98 1","pages":"1097-1098"},"PeriodicalIF":9.3,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145209156","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":"Optimizing Estimation: Perspective on Drug Dosing Using New CKD-EPI Equations.","authors":"Edward J Filippone, Walter K Kraft","doi":"10.1093/clinchem/hvaf031","DOIUrl":"10.1093/clinchem/hvaf031","url":null,"abstract":"","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":" ","pages":"1014-1017"},"PeriodicalIF":6.3,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143741818","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":"Supratherapeutic Carbamazepine Concentration Following a Recent SARS-CoV-2 Infection.","authors":"Maxwell L Harsha,Mark A Marzinke","doi":"10.1093/clinchem/hvaf062","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf062","url":null,"abstract":"","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"76 1","pages":"1018-1022"},"PeriodicalIF":9.3,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145209157","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":"Commentary on Supratherapeutic Carbamazepine Concentration Following a Recent SARS-CoV-2 Infection.","authors":"Sarah R Delaney","doi":"10.1093/clinchem/hvaf091","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf091","url":null,"abstract":"","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"99 1","pages":"1023"},"PeriodicalIF":9.3,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145209158","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":"Commentary on Supratherapeutic Carbamazepine Concentration Following a Recent SARS-CoV-2 Infection.","authors":"Adina Badea","doi":"10.1093/clinchem/hvaf104","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf104","url":null,"abstract":"","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"157 1","pages":"1022"},"PeriodicalIF":9.3,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145209155","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}
Clinical chemistryPub Date : 2025-10-02DOI: 10.1093/clinchem/hvaf086.131
Christina Higgins, John Zak, Michael Suster
{"title":"A-135 Characterization of refrigerator-stable erythrocyte and platelet product with utility for clotting assay external control and experimental applications","authors":"Christina Higgins, John Zak, Michael Suster","doi":"10.1093/clinchem/hvaf086.131","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.131","url":null,"abstract":"Background Shelf-stable material to accurately replicate whole blood clotting for use as proficiency/external control, validation samples, and drug/biomarker discovery tools is not widely available. During clot formation, activated platelets change shape and aggregate, and erythrocytes (RBCs) are deformed by contractile forces; therefore, functional RBCs and platelets responsive to clotting pathway signaling are both fundamental to a representative clotting control. Standard storage methods preserve RBCs for up to 42 days and platelets up to 7 days, with functional deterioration during that period. Cryopreservation preserves clotting function for longer periods, but lot-to-lot performance is not well-characterized and cryopreserved material presents challenges for use as point-of-care external control. Lyophilization causes extensive membrane damage. Other membrane stabilization methods successfully prevent hemolysis but interfere with clotting. Here, we show that increasing RBC resistance to shear in conjunction with preserving RBC deformability and platelet responsiveness generates a refrigerator-stable product with acceptable clotting time precision and stability for 75 days post-draw, suitable as a proxy whole blood clotting sample. Methods Two lots of RBC/platelet material produced under ISO13485 were stored at 2–8°C during characterization, with periodic equilibration to room temperature, mimicking typical assay external control handling. The ClotChip System (IUO), intended for point-of-care use and utilizing dielectric spectroscopy to determine whole blood clotting time, was employed to assess clotting function. Both lots underwent 20-day precision assessment of clotting performance in the presence of normal plasma or clotting-factor deficient plasma (CLSI EP05-03). Material was also assessed for long-term and in-use stability assessments of clotting function (CLSI EP25). RBC deformability was assessed weekly via ektacytometry (LorrcaMaxSis) under normoxia and hypoxia. Complete blood counts (CBCs) were periodically measured (Abacus3CP). Responsiveness of RBCs and platelets to clotting factors was evaluated on ClotChip after combination with plasmas whose clotting factor levels varied. Results Clotting time repeatability was 3.3%-13.8% for both lots and total imprecision was 4.6%-15.0%. Mean clotting time for material combined with normal plasma remained within 20% of initial values for up to 75 days after blood draw; in-use stability at room temperature remained within 10% of initial values for the full period tested (5.5 hrs). RBC deformability (EImax) under normoxia or hypoxia fell within the fresh whole blood reference range and exhibited no significant change over 75 days (p>0.05) (see Figure). Half-maximal shear stress required to elongate cells was ∼30% elevated vs fresh blood at the start of storage, increased over time, and plateaued at 3-4x fresh blood levels. CBCs at baseline and 10 weeks indicated minimal changes in RBC o","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"75 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145202929","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}
Clinical chemistryPub Date : 2025-10-02DOI: 10.1093/clinchem/hvaf086.640
Wenying Zhang, Kevin Wen, Jack Bleesing, Mei Xin
{"title":"B-252 Functional Validation of Novel FAS Intronic and Splice Region VUS Through Minigene Assays","authors":"Wenying Zhang, Kevin Wen, Jack Bleesing, Mei Xin","doi":"10.1093/clinchem/hvaf086.640","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.640","url":null,"abstract":"Background Autoimmune lymphoproliferative syndrome (ALPS) is a rare genetic disorder characterized by chronic lymphadenopathy, splenomegaly, cytopenias, and an increased risk of lymphoma. Molecular genetic diagnosis is essential for the accurate diagnosis and management of ALPS, particularly due to its overlapping clinical features with autoimmune lymphoproliferative immunodeficiency (ALPID). About 80% of ALPS cases result from germline or somatic pathogenic variants in FAS (ALPS-FAS, ALPS-sFAS), primarily through dominant-negative interference or haploinsufficiency. The FAS mutation spectrum includes nonsense, frameshift, missense, splicing defect variants, and copy number variants. Notably, around 13% ALPS-FAS cases are attributed to splice site/region mutations in FAS that disrupt splicing. However, novel splice region or deep intronic FAS variants are often classified as variants of unknown significance (VUS) due to the lack of functional validation, making their precise classification difficult to determine. This study aims to identify and characterize novel intronic or splice region FAS VUS found in a cohort of 1,488 ALPS cases at a pediatric center, as well as those reported in the ClinVar database. Methods We retrospectively reviewed the records of 1,488 patients with suspected ALPS referred to our institution for either the FAS gene sequencing or ALPS next-generation sequencing (NGS) panel between 2005 and 2023. Previously unreported variants with potential splicing effect were identified. Additionally, we reviewed the ClinVar database for rare FAS variants with predicted effects on splicing. To functionally assess these variants, we plan to use a minigene assay, which involves constructing a simplified version of the gene containing the exon of interest and its flanking introns into a plasmid. This plasmid is then transfected into cells to analyze how the variant affects the resulting mRNA transcript. Results We identified 19 novel FAS variants with predicted splicing effect in 30 independent probands from our cohort. These variants were distributed across eight FAS intronic splicing regions, including one synonymous change in a deep exonic region predicted to activate a nearby cryptic splice donor. Additionally, a review of the ClinVar database revealed 19 previously unreported rare splice region variants in FAS, of which, 13 were predicted to affect splicing. We will use the minigene system to experimentally validate the functional consequences of these variants. Conclusion FAS pathogenic variants affecting splicing represent a significant contributor to ALP-FAS and ALP-sFAS. The minigene assay will provide crucial functional evidence to further characterize the pathogenicity of rare VUS with predicted splicing effects, thereby improving the molecular diagnosis for ALPS. This approach is particularly valuable when RNA samples are unavailable from affected patients, enabling a more comprehensive genetic evaluation of ALPS.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"5 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145203000","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}
Clinical chemistryPub Date : 2025-10-02DOI: 10.1093/clinchem/hvaf086.253
Marina Bezerra, Rachel Petrola, Edlâny Milanez
{"title":"A-264 Urine Culture Trends from 2022 to 2025: A Review of Microorganism Prevalence","authors":"Marina Bezerra, Rachel Petrola, Edlâny Milanez","doi":"10.1093/clinchem/hvaf086.253","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.253","url":null,"abstract":"Background Urinary tract infections (UTIs) are among the leading causes of bacterial infections, affecting millions of people annually and impacting public health. These infections can affect any part of the urinary system, ranging from mild cases to complications like pyelonephritis and sepsis. Several factors can influence the development and severity of UTIs, including age, sex, and comorbidities such as diabetes mellitus. This study aims to analyze the epidemiological profile of UTIs in outpatients from a Brazilian population, investigating the distribution of etiological agents and their association with age, sex, diabetes, and bacterial colony counts. The use of big data for laboratory analysis provides a broad approach to understanding the behavior of these infections, their impact on clinical management, and corroboration with the literature. Methods This epidemiological, cross-sectional study analyzed the distribution of etiological agents in urine cultures from outpatients at a private laboratory in the Northeast region of Brazil. Data between January 2022 and February 2025 were extracted from the LIS system. Urinalysis and urine culture results were analyzed using Sysmex® and Vitek - 2 Compat ® equipment, considering bacterial colony counts and self-reported diabetes status. The population was stratified by sex and age. Results The population was mainly female (79%), with a mean age of 55 ± 22 years. Bacterial growth was observed in 22,326 (19.8%) of the urine cultures (N=112,506). The main pathogens identified were Escherichia coli (12%; N=13,259), Klebsiella pneumoniae (3.2%; N=3,652), Proteus mirabilis (0.9%; N=1,035), and Enterococcus faecalis (0.9%; N=1,002). Extended-spectrum beta-lactamase (ESBL)-positive cases accounted for 14% (N=1,450). Among the ESBL-positive cases, five patients had bacterial growth exceeding 1,000,000 CFU/mL (Klebsiella pneumoniae N=4, Proteus mirabilis N=1), with two cases of dual colonization (Klebsiella/E. coli and Proteus/E. coli). Among the patients, 15% (N=16,473) self-reported as diabetic. This group had a higher prevalence of ESBL-positive infections (18%, N=384), and in cases with more than one isolated microorganism, ESBL positivity was observed in 38%. Candida glabrata was more prevalent in diabetic patients. Conclusion The analysis revealed that most cases occurred in women, particularly those aged 18 to 50 years, with Escherichia coli as the most frequent pathogen. Diabetic patients had a higher prevalence of infections caused by ESBL-positive microorganisms, especially in mixed infections. Additionally, Candida glabrata was more prevalent in this group. The findings show that the prevalence of main UTI pathogens remains similar to that reported in recent years. This study emphasizes the importance of regularly updating epidemiological data to improve clinical management strategies for these infections.","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":"145203006","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}
Clinical chemistryPub Date : 2025-10-02DOI: 10.1093/clinchem/hvaf086.710
Grace Williams
{"title":"B-323 Evaluating the Detection of 215 Fentanyl Analogs and Synthetic Opioids in Urine Using Four Commercial Immunoassays","authors":"Grace Williams","doi":"10.1093/clinchem/hvaf086.710","DOIUrl":"https://doi.org/10.1093/clinchem/hvaf086.710","url":null,"abstract":"Background America continues to be plagued by an opioid epidemic, and the third wave, predominated by fentanyl analogs has yet to abate. The detectability of fentanyl analogs and synthetic opioids is of critical concern to clinical and forensic laboratories. The US Centers for Disease Control and Prevention has coordinated production of a Traceable Opioid Material® Kits (TOM Kits®) to support laboratory detection of current and potentially emerging opioids as well as common co-drugs found in fentanyl-containing samples. Previously published studies by this group have focused on analyzing compound structures in relation to assay detectability to predict the likely target epitope. The final data analysis of these over 1,800 measurements will also include this prediction. Methods From the TOM Kits®, 215 opioids were evaluated. These were analyzed using four commercially available fentanyl immunoassays: ARK™ Fentanyl II, Immunalysis Fentanyl Urine HEIA®, Immunalysis Fentanyl Urine SEFRIA® Drug Screening Kit, and the Lin-Zhi Fentanyl Enzyme Immunoassay. The detectability of the opioids was initially evaluated by preparing each opioid in certified drug-free human urine at 1 ng/mL, then analyzing the sample using the four immunoassays to determine if the analog screened positive in singlicate. Testing of that opioid was discontinued if the initial results was positive. If the result was negative, the resultant value was evaluated to determine whether a concentration of 10 ng/mL or 100 ng/mL would be appropriate for the second analysis. Opioids that did not screen positive at a concentration of 100 ng/mL were considered undetected by that immunoassay. Results The difference in reactivity of the immunoassay’s reagents was evaluated in conjunction with the chemical structure of each opioid. All four immunoassays detected 106 of the opioids at the concentrations tested. Eighty-two opioids had variable cross-reactivity with the four immunoassays determined by the unique epitope for each reagent antibody. 28 opioids were not detected by any assay and 17 of these were the emerging synthetic opioids. At the lowest concentration tested (1 ng/mL), the ARK II assay detected 36 compounds, the SEFRIA detected 74, LZI detected 5, and the HEIA detected 18. Higher concentration testing was conducted on the other compounds. The undetected opioids included the surgical anesthetic parent compounds remifentanil and alfentanil, and sufentanil metabolite norsufentanil. Additionally, three carfentanil analogs were not detected by the four immunoassays. Of the 34 compounds only detected by one assay, 27 of those positive results were from the Lin-Zhi assay. Conclusion This information will be of use in both clinical and forensic settings in evaluation of the potential false-positive or false negatives in urine fentanyl screening. The detectability of fentanyl analogs and synthetic opioids varies by assay and it may be possible to predict the detection or lack thereof for a par","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":"145203151","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}