BACKGROUND:Lyme disease, a vector-borne zoonosis caused by Borrelia species, is classified into early localized and late disseminated infection. Left untreated, infected patients face multisystem pathology involving the joints, heart, and peripheral and central nervous system, making early antibiotic therapy essential. Lyme diagnosis with standard 2-tier test (STTT) and a modified 2-tier test utilize sequential serological assays. In this study, we evaluated the InBios Lyme Detect™ Multiplex ELISA (RUO) (InBios ELISA), a one-step method that combines screening and confirmatory tests. While a recent publication (Curr. Issues Mol. Biol. 2021;42:333-84.) demonstrated good performance of the InBios ELISA during early stages of Lyme disease, this study aimed to assess assay performance relative to STTT and to characterize IgG and IgM reactivity compared to standard immunoblot. METHODS:A convenience sampling of 119 residual sera previously characterized by STTT were analyzed for Lyme antibodies using the InBios ELISA. The evaluation quantified antigen reactivity using imaging and machine-learning analysis, which triggered simultaneous confirmatory analysis to provide an inclusive final interpretation. RESULTS:Among the 119 serum samples, InBios ELISA demonstrated 99.2% concordance with STTT. A single discordant result was observed for one STTT-positive sample with IgM confirmation. Concordance between second-tier immunoblots (IgM or IgG) and InBios IgM or IgG index was 76.2% for both. CONCLUSIONS:This study shows that the InBios ELISA can (with minimal discordance) interpret both screen and confirmatory results in one step. Overall, there is a potential to replace the 2-tier test with one-step InBios ELISA to enable rapid turnaround and improve diagnosis of Lyme.
BACKGROUND:Point-of-care (POC) testing and triage liaison physicians could help alleviate the impact of emergency department (ED) overcrowding. The aim of our study was to evaluate the diagnostic performance of the TriageTrue POC assay for the rapid rule-out of myocardial infarction based on a single measurement of high-sensitivity cardiac troponin I (hs-CTnI). The diagnostic performance was compared to measurements obtained with the Vitros 3600 assay, taking into account the cutoffs recommended by the European Society of Cardiology. METHODS:The study compared results of troponin obtained simultaneously on the TriageMeterPro device from whole blood and plasma samples (n = 139) and the hs-cTnI assay on the Vitros 3600 instrument from EDTA plasma samples (n = 225). The diagnostic performance of the 3 methods was compared, including negative predictive value and sensitivity as well as positive predictive value and specificity. Concordance between the methods with disease state samples was then assessed using the Cohen kappa test. RESULTS:An excellent correlation between plasma and whole blood samples was achieved with the TriageTrue with a coefficient of correlation >0.99 and a bias of +8.2 (±45, with 95% CI 0.4 to 16.0) ng/L. A significant overestimation (around 47%) of the values obtained with the TriageTrue compared with those of the Vitros was also observed. Our results confirmed the acceptable and comparable diagnostic accuracy to the established hs-cTnI-Vitros assay, with a negative predictive value of 100% to rule-out myocardial infarction. CONCLUSION:Our results demonstrated that the TriageTrue hs-cTnI whole blood test could serve as an alternative method for ruling out or confirming non-ST-elevation myocardial infarction in the prehospital setting using a single POC troponin measurement.
BACKGROUND:High-sensitivity cardiac troponin assays, such as troponin T (hs-cTnT), underpin the diagnosis and risk stratification of myocardial injury, with interpretation anchored to the 99th percentile upper reference limit (URL). As clinical laboratories transition from fifth-generation (Gen5) to sixth-generation (Gen6) hs-cTnT assays, analytical shifts may alter threshold crossing and timing of elevation near the 99th percentile URL, where clinical classification is highly consequential. However, real-world data describing the impact of this transition remain limited. METHODS:In this retrospective paired analysis, residual specimens from patients undergoing hs-cTnT testing were measured using Roche Gen5/Gen6 assays. A total of 3617 paired measurements from 1847 encounters (1737 patients) were analyzed longitudinally. Patient encounters were assessed for time to elevation above the 99th percentile URL; peak concentration; modeled 0-, 1-, and 3-hour pathway classification; and kinetic behavior. RESULTS:Overall concordance between Gen5 and Gen6 was high for classification of hs-cTnT measurements and encounter peak values relative to the 99th percentile URL. Differences concentrated near the 99th percentile URL, where Gen6 crossed this threshold earlier than Gen5 and the converse was infrequent (2.6% vs 0.1%; P = 0.0001). In the modeled 0/1/3-hour rule-out/rule-in pathway, agreement between assays remained, although some encounters differed in classification between rule-out, indeterminate, and abnormal categories. Gen6 also demonstrated larger relative changes during the rising phase and steeper post-peak declines, with apparent elimination more similar to CK-MB than Gen5. CONCLUSIONS:Gen5 and Gen6 hs-cTnT assays demonstrate strong overall agreement, although small analytical differences near decision thresholds produce measurable differences in timing of elevation and modeled clinical classification.
BACKGROUND:CIZ1B is an alternatively spliced protein fragment of the Cyclin-dependent kinase interacting protein 1 (CIP1)-interacting zinc finger protein (CIZ1) complexed with fibrinogen alpha chain (FibA), forming a single parameter protein analyte (CIZ1B-FibA). The CIZ1B blood biomarker has potential to indicate the presence of early-stage lung cancer and could alter clinical practice. METHODS:We report configuration and calibration of a sandwich ELISA for measurement of CIZ1B-FibA that uses a new and highly specific CIZ1B exon junction-selective monoclonal antibody to capture the analyte, and an anti-fibrinogen antibody to detect it, in microliter quantities of plasma from lung cancer patients. RESULTS:The format is tested across 3 independent sample sets encompassing cancer and control samples, yielding Receiver Operating Characteristic area under curve (ROC AUC) values of 0.82 for Set 1 (n = 48), 0.81 for Set 2 (n = 38), and 0.86 for Set 3 (n = 57), indicating discrimination for individuals with lung cancer including those with stage I or II disease (Set 3). However, comparison of the control plasma samples in each set, which were sourced in 3 countries with site-specific plasma isolation processes, revealed baseline differences indicating a note of caution regarding sensitivity to pre-analytic variables. Application of set-specific thresholds, determined by the maximum Youden Index, returned negative predictive values (NPV) of 95%, 77%, and 97% for Sets 1, 2 and 3, respectively. CONCLUSION:We describe an affordable and scalable blood test which can measure CIZ1B-FibA and now requires further validation of analytical parameters and investigation of potential biological variables.
BACKGROUND:To reduce the spread of carbapenem-resistant gram-negative bacteria, the Centers for Disease Control recommends rectal and perirectal swab surveillance using the Cepheid Xpert® Carba-R Assay. An expressed limitation of the assay is lack of validation data for patients <21 years. To address this limitation, an in-house validation was performed using pediatric stool specimens from patients <21 years. METHODS:Pediatric validation of the Cepheid Copan Dual Swab Collection Device and Xpert® Carba-R Assay was performed using pooled stool specimens from 17 patients ages <1 to 21 years, spiked with Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, Enterobacter cloacae, and Pseudomonas aeruginosa harboring β-lactamase mechanisms (Klebsiella pneumoniae carbapenemase, New Delhi metallo-β-lactamase, oxacillinase-48-like carbapenemase, Verona integron-encoded metallo-β-lactamase, and imipenemase). Validation was supported by molecular and culture analysis of 747 pediatric clinical specimens. RESULTS:Pediatric stool-spiked rectal swabs produced Cepheid Carba-R results with 100% accuracy (SD < 1; CV < 4%) and excellent precision (SD < 1, CV < 4%). Clinical carbapenemase surveillance of >24 000 rectal specimens screened by the Carba-R assay (2018-2024) showed lower carbapenemase-detected percent positivity in patients ages 0 to 20 years (3.0%-4.2%) compared with adults ages 21 to >65 (7.8%-12.7%) (χ2, P < 0.00001). No significant age-group differences were observed in the ability to isolate detected β-lactamase mechanisms from patient specimens. CONCLUSION:The Cepheid Copan Dual Swab Collection Device with the Xpert® Carba-R Assay is a valid method for rapid (<1 h) screening of carbapenemase-producing organisms (β-lactamase mechanisms: Klebsiella pneumoniae carbapenemase, New Delhi metallo-β-lactamase, oxacillinase-48-like carbapenemase, Verona integron-encoded metallo-β-lactamase, and imipenemase) in pediatric patients.
BACKGROUND:Current laboratory workflows fail to reliably capture intravenous fluid contamination of chemistry results, leading to diagnostic uncertainty and misinformed clinical decisions. These events cause predictable error patterns, but no gold-standard detection method or definition exists, hindering optimization efforts. We sought a scalable detection solution for these errors to guide quality initiatives and research efforts. METHODS:We developed an ensemble of LightGBM classifiers to retrospectively identify the typical anomaly-with-resolution pattern seen in contaminated results by simulating contamination from common fluid compositions into authentic patient results. Models were evaluated by cross-validation and manual review, applied to a held-out 1-year validation cohort, and used to benchmark existing delta-check and published detection approaches. RESULTS:Models produced excellent discrimination between real results and simulated contamination. When applied to real-world data, results flagged as contamination consistently exhibited the expected anomaly-with-resolution pattern and were enriched for abnormal and critical results that often exceeded reference change values across multiple analytes. Predicted contamination rates varied substantially by clinical setting, with the highest rates in emergency departments, operating rooms, and intensive care units. The retrospective machine learning ensemble provides a scalable benchmarking tool for evaluating routine laboratory workflows and published rule-based or delta check methods. CONCLUSIONS:Simulation-based machine learning provides a scalable, high-fidelity "silver standard" for retrospective identification of intravenous fluid contamination. This approach enables robust benchmarking of detection strategies, supports optimization of practical rule-based workflows, and offers actionable insights for laboratory quality improvement and patient safety initiatives.
BACKGROUND:Prostate-specific antigen (PSA) is a biomarker used for detection, screening, and follow-up of prostate cancer. Traditional PSA quantification requires venipuncture, which poses challenges in collection, storage, and transportation. Dried blood spot (DBS) technology presents a promising alternative for measuring PSA levels, potentially facilitating telemedicine, and large-scale screening programs. METHODS:PSA concentrations were measured in paired capillary finger-stick DBS and venous serum samples from 75 patients using a Siemens immunochemistry analyzer. For DBS samples, PSA was extracted using PBS prior to analysis. Additional validation of stability, hematocrit effects, precision, and limits of blank and quantitation was performed according to corresponding Clinical and Laboratory Standards Institute standards. RESULTS:The DBS PSA assay demonstrated good analytical performance, with total CVs of 4.5% and 6.1% at PSA concentrations of 11.5 µg/L and 3.8 µg/L, respectively. Limit of blank, limit of detection, and limit of quantitation were 0.24 µg/L, 0.28 µg/L, and 0.70 µg/L, respectively. Method comparison showed strong agreement between venous serum and finger-stick DBS (R2 = 0.987) with minimal bias. Stability studies showed that PSA remained stable for up to 31 days between -20°C and +30°C. Hematocrit affected measured PSA concentrations, but results remained within predefined total allowable error limits across 0.25-0.50 L/L. Variations in double spotting, blood volume, and number of spots did not affect PSA concentrations with a consistent trend. CONCLUSIONS:PSA can be accurately measured from finger-stick DBS on an automated high-throughput immunochemistry analyzer. This method is less invasive for patients and may facilitate at-home self-sampling supporting (tele)diagnostics, screening, and follow-up.
