Clinical Immunoassay Research Articles

A-380 Concordance of Truvian's Point-of-Care Blood Testing Analyzer to Central Laboratory Testing

Abstract Background Truvian has developed a fully automated blood testing analyzer (TruAnalyzer) capable of running a panel of clinical chemistry, immunoassay and hematology assays from a low-volume blood sample. Truvian's compact instrument was designed to deliver a convenient and affordable alternative to off-site traditional labs, providing lab-accurate rapid insights from a single, small sample of blood with no upfront pre-processing required to inform health decisions at the point of care. Here, we evaluate the precision and accuracy of a comprehensive wellness panel tested on the TruAnalyzer and compare its performance to FDA cleared devices. Methods TruAnalyzer performance was assessed for both precision and accuracy. For the precision studies, two commercially available controls (one for plasma-based assays and one for blood-based assays) were added to the Truvian consumables and loaded into the TruAnalyzer. Six replicates were run on each of the ten instruments (N = 60). Coefficient of variance (CV) analysis was performed and compared against pre-established requirements. For method comparison studies, 50 unique donors were consented and enrolled in an IRB approved study and 68 donor samples were collected over a 3-day period. For each donor, three 4-mL tubes of blood were drawn: 1) a Lithium Heparin (LiHep) sample for the TruAnalyzer clinical chemistry and hematology panel, 2) a LiHep gel tube for the Roche Cobas c311 clinical chemistry assays, and 3) an EDTA sample for the Sysmex PocH-100i complete blood count with 3-part differential. All samples were processed within 1 hour of collection. Using only 300 µL sample volume, the TruAnalyzer reported results for 23 analytes including CMP (no electrolyes), Lipid, HbA1c, and CBC with 3-part differential. Concordance to comparator devices was determined by Bland-Altman analysis. Results For the precision study, 13 out of 14 (93%) chemistry analytes had a between-system CV of ≤5.8%. For hematology, 5 out of 5 (100%) analytes had a between-system CV of ≤6%. For the method comparison study, RBC counts showed 98% of samples tested being within 6% of comparator values. WBC and platelet counts had 97% of samples tested being within 10% and 15% of comparator values respectively. 95% of hematocrit samples were within 6% of comparator values and 98% of hemoglobin samples were within 7% of comparator values. All hematology analytes showed equivalency to Sysmex PocH-100i as determined by Bland-Altman equivalency analysis. For clinical chemistry analytes, 14 out of 15 (93%) analytes showed equivalency to Roche Cobas c311 as determined by Bland-Altman equivalency analysis when CLIA ATE guidelines were applied. 7 out of 15 clinical chemistry analytes had ≥90% of results within ATE. 5 out of 15 clinical chemistry analytes had ≥80% of results within ATE. Conclusion The Truvian blood testing analyzer is the first multi-modality system capable of running hematology, clinical chemistry and immunoassays from a single, low-volume blood sample. Results from this study demonstrate good precision for the majority of panel analytes and excellent concordance to FDA cleared comparators for assays evaluated in this study.

A-189 Volume Matters: Continuous Improvement to Reduce Blood Collection Volumes and Collection Tube Utilization

Abstract Background Clinical laboratories are constantly changing with automated analyzers and total lab automation (TLA) implemented and replaced over time. Some benefits of newer technologies include decreased specimen volume requirements, less need for repeat testing, and greater throughput. Recent implementation of new analyzers and replacement of TLA in the Central Clinical Laboratory (CCL) at Mayo Clinic, Rochester, MN, prompted the laboratory to reassess blood collection volumes for commonly ordered tests. Objectives The aim of this study was to evaluate whether updating the blood collection volumes for clinical chemistry and immunoassay tests performed in the CCL could reduce the volume of blood collected from patients and the number of blood collection tubes utilized. Methods Nearly 100 different serum assays from the CCL test menu were reviewed including the basic and comprehensive metabolic, hepatic function, renal function, electrolyte, and lipid panels as well as thyroid function tests, enzymes, hormones, electrolytes, and iron status tests. Cortisol, ferritin, folate, and Vitamin B12 testing were performed on the Beckman DxI800; all other testing was on Roche Diagnostics Cobas 8000 chemistry (ISE, c701, c502) and immunoassay (e801) analyzers. Updated blood volumes for each assay were calculated utilizing manufacturer’s analytical volumes and “dead volume” requirements. Baseline data retrieved from the laboratory information system (LIS) included blood collection volumes and number of tubes collected for 128 patients with physician-orders for laboratory testing on 5/2/21. The collection logic was then updated in the test LIS environment using the new blood volumes requirements and applied to the same 128 orders. Blood volumes and number of tubes collected per order were compared before and after the volume updates. Results Baseline data from 128 unique orders showed that 414 total tubes were collected with a median(range) of 3 (2–6) tubes per order and 5 (1–18) tests per tube. The total volume of blood requested at baseline was 2065 mL. Post-intervention, 197 tubes were needed with a median(range) of 2 (1–3) tubes per order and 13 (1–30) tests per tube. The total volume of blood requested after updating volumes was 851 mL. Conclusions The practice of reviewing and updating specimen volume requirements when replacing or implementing new analyzers or TLA can greatly reduce the volume of blood collected from patients and the number of blood collection tubes per order. In this study of 128 physician orders for common laboratory tests, updating blood collection information in the LIS reduced the requested blood collection volumes by 59% and decreased the number of blood collection tubes required by 52%. This not only benefits patients because less blood is collected but also conserves blood collection tubes and reduces supply chain demands. Additionally, fewer tubes on the TLA system has the potential to improve throughput and test turnaround time.

A-182 The journey From Conceptualizing, Designing, and Implementing Our Integrated Smart Core Lab at Kokilaben Dhirubhai Ambani Hospital (KDAH) & Medical Research Institute, Mumbai, India

Abstract Background KDAH established in 2009, is a 550 bedded tertiary care, multispecialty hospital in Mumbai, India. Annually the hospital manages about 300 000 patients, the clinical lab delivers >1 750 000 results with Compound Annual Growth Rate of 18 %. In the last 14 years, the clinical lab has expanded; increasing the test services, adding equipment, recruiting staff, and requesting for more space. There is increasing pressure to improve speed of service to impact early patient outcomes keeping an awareness on cost, non-availability of space for expansion. There is also demand to bring in new clinical tests and increase outreach beyond the hospital. In October 2018, the laboratory and hospital management decided to apply principles of Lean and design thinking to laboratory processes. The Smart Core Laboratory conceptualized was an outcome of this work and is focused on delivering results in the most efficient way, in terms of quality, cost, and speed. Methods The team of experts from various lab disciplines and lean consultants, started evaluating the end-to-end process from sample received at the central station to results review, reporting and sample disposal 1. Process Map: The process steps are classified and evaluated by the core team as value added (VA) and non-value added (NVA) & business-value added or necessary waste. Process Maps charts were generated for the following sample flow. a. Central Sample Receipt to Section. Verification, Registration & Distribution Process.b.In Lab preanalytical, analytical, post analytical processes: Clinical Chemistry, Immunoassay, Infectious Serology. (Serum, Plasma Fluoride / Heparin)Hematology (EDTA Whole Blood)Hemostasis (Citrate Plasma) 1. Value Stream Map A detailed Value Stream Map of all the actions for the above processes was generated to determine VA and NVA process steps 3. Spaghetti Mapping: Motion Study Observation and analysis of the Spaghetti mapping diagrams exposed inefficient layouts and identified areas with a lot of unnecessary movement. This helped to decide optimization of the flow and re-organization of the entire lab section Results & Discussion Based on the analysis of the data generated from the lean tools and identifying process waste and non-value added steps the following immediate improvements were implemented a. Combining steps extra-processing at centrifugation at each lab sectionb.Decreasing sample vacutainers by reducing number of sample drawsc.Eliminating Overproduction by removing extra barcode printing and registersd.Using Staff Creatively: Reorganize IQC, Calibration and maintenance to off peak hourse.Space Optimization. Conclusion This consolidation approach has enabled us to free up at least 341 sq ft prime lab space (≈14 % reduction), decrease staff motion & sample transportation. Approximately 50% simplification in overall processes is achieved. It also allowed reduction in additional patient sample draws by at least 40 %. The team could use this lean analysis to conceptualize and design a multidisciplinary Automation solution that would consolidate 5 sections namely Clinical Chemistry, Immunoassay, Infectious Serology, Hematology and Hemostasis in the Smart Core Laboratory.

Quantitative monitoring of SARS-CoV-2 mediated by the intrinsic Raman signal of silicon nanoparticles and SiC@RP composite semiconductor SERS substrate

Non-metallic surface-enhanced Raman scattering (SERS) demonstrates an attractive potential in clinical immunoassay thanks to the brilliant biocompatibility and chemical enhancement of semiconductor substrates. Herein, SERS-based quantitative assay of SARS-CoV-2 in saliva was carried out by constructing SiC@RP nanotowers (NTs) and Si nanoparticles. Ascribed to the efficient light absorption and molecular enrichment capacity of the hierarchical tower morphology as well as the synergistic chemical enhancement in the semiconductor heterojunction, the SiC@RP NTs achieved a minimum limit of detection as 7.6 × 10-11 g/mL for SARS-CoV-2. Concurrently, the correction of the detection signal by the intrinsic Raman signal of Si nanoparticles drastically improved the stability and reliability of the detection, facilitating a relative standard deviation (RSD) data within ± 9.53%. Ultimately, the real-time SERS monitoring of saliva samples displayed an ultra-high response rate of no less than 83.2%. Such a non-metallic SERS immunoassay with high sensitivity and attractive reliability is expected to play a key role in future clinical monitoring application.

A panel of seven protein tumour markers for effective and affordable multi-cancer early detection by artificial intelligence.

155 Background: Cancer early detection aims at reducing cancer deaths. Unfortunately, many established cancer screening technologies are not suitable for use in low- and middle-income countries (LMICs) due to cost, complexity, and dependency on extensive medical infrastructure. Methods: Nearly 10,000 participants [1959 cancer cases (containing more than nine common cancer types) and 7423 non-cancer cases] were divided into one training and two independent validation cohorts. One tube of peripheral blood samples was collected from each participant and quantified using a panel of seven selected protein tumour markers (PTMs) by a common clinical electrochemiluminescence immunoassay analyser. An algorithm named OncoSeek was established using artificial intelligence (AI) to distinguish cancer from non-cancer cases by calculating the probability of cancer (POC) index based on the quantification results of the seven PTMs and clinical information including sex and age of the subjects, and to predict the possible affected tissue of origin (TOO) for those who have been detected with cancer signal. Results: The conventional clinical method relied only on a single threshold for each PTM which would make a big problem when combining the results of those markers, the false positive rate would accumulate as the number of markers increased. Nevertheless, OncoSeek was empowered by AI technology to significantly reduce the false positive rate, increasing the specificity from 56·9% [95% confidence interval (CI): 55·8% to 58·0%] to 92·9% (95% CI: 92·3% to 93·5%). In all cancer types, the overall sensitivity of the OncoSeek test was 51·7% (95% CI: 49·4% to 53·9%). And the performance was generally consistent in the training and the two validation cohorts. The sensitivities ranged from 37·1% to 77·6% for the detection of the nine common cancer types (breast, colorectum, liver, lung, lymphoma, oesophagus, ovary, pancreas, and stomach), which account for ~59·2% of global cancer deaths annually. Furthermore, it has shown excellent sensitivity in several high-mortality cancer types for which there are lacking routine screening tests in the clinic, such as the sensitivity of pancreatic cancer was 77·6% (95% CI: 69·3% to 84·6%). The overall accuracy of TOO prediction in the true positives was 66·8%, which could assist the clinical diagnostic workup. Conclusions: OncoSeek significantly outperforms the conventional clinical method, representing a novel blood-based test for multi-cancer early detection (MCED) which is a non-invasive, easy, efficient, and robust approach. Moreover, the accuracy of TOO facilitates the follow-up diagnostic workup and this method is affordable (less than $25) and accessible requiring nothing more than a blood draw at the screening sites, which makes it acceptable and sustainable in LMICs.

Development of matrix-based reference materials for 17 beta-estradiol by the recommended reference method of ID-LC-MS/MS.

We developed and evaluated two-level, namely 2017011 and 2017012, serum-based reference materials (RMs) for 17 beta-estradiol (17 β-E2) by the reference method of isotope dilution liquid chromatography tandem mass spectrometry (ID-LC-MS/MS) from the remaining serum samples after routine clinical tests, to help improve clinical routine testing and provide the traceability of results. This paper describes the development process of these RMs. The National Metrology Institute of Japan (NMIJ) certified reference material (CRM) 6004-a was used as the primary RM for the measurement of 17 β-E2. These serum-based RMs showed satisfactory homogeneity and stability. They also assessed the commutability between the reference method and the three routine clinical immunoassay systems. Besides, a collaborative study was carried out in five reference laboratories, all of which had been accredited by the China National Accreditation Service for Conformity Assessment (CNAS) in accordance with ISO/WD 15725-1. Statistical analysis of raw results and uncertainty assessment obtained certified values: 2017011 was 445.2 ± 39.0pmol/L, and 2017012 was 761.9 ± 35.5pmol/L.

Copper(II) Affects the Biochemical Behavior of Proinsulin C-peptide by Forming Ternary Complexes with Serum Albumin.

Peptide hormones are essential signaling molecules with therapeutic importance. Identifying regulatory factors that drive their activity gives important insight into their mode of action and clinical development. In this work, we demonstrate the combined impact of Cu(II) and the serum protein albumin on the activity of C-peptide, a 31-mer peptide derived from the same prohormone as insulin. C-peptide exhibits beneficial effects, particularly in diabetic patients, but its clinical use has been hampered by a lack of mechanistic understanding. We show that Cu(II) mediates the formation of ternary complexes between albumin and C-peptide and that the resulting species depend on the order of addition. These ternary complexes notably alter peptide activity, showing differences from the peptide or Cu(II)/peptide complexes alone in redox protection as well as in cellular internalization of the peptide. In standard clinical immunoassays for measuring C-peptide levels, the complexes inflate the quantitation of the peptide, suggesting that such adducts may affect biomarker quantitation. Altogether, our work points to the potential relevance of Cu(II)-linked C-peptide/albumin complexes in the peptide's mechanism of action and application as a biomarker.

A panel of seven protein tumour markers for effective and affordable multi-cancer early detection by artificial intelligence: a large-scale and multicentre case–control study

A panel of seven protein tumour markers for effective and affordable multi-cancer early detection by artificial intelligence: a large-scale and multicentre case–control study

Dual-Labeled Octahedral Gold and Magnetic Microsphere Electrochemical Immunosensor for Ultrasensitive Determination of Carbohydrate Antigen-199 (CA199) by Differential Pulse Voltammetry (DPV)

To precisely detect CA199 antigen, a novel electrochemical immunosensor based on horseradish peroxidase (HRP) and glucose oxidase (GOD) double enzyme system was prepared. Thiol was adsorbed on the surface of nano-octahedral gold through Au-S self-assembly; the second antibody was labeled by glutaraldehyde ligase as a signal amplification reagent. Amino magnetic microspheres were used to connect GOD and bovine serum albumin (BSA) through glutaraldehyde. The biosensor displayed low detection limits of 0.2 U/mL and wide linear range (0.5–200 U/mL). This novel immunosensor improves the sensitivity of current detection, showing promising application prospects in the clinical immunoassay detection of CA199.

A panel of seven protein tumor markers for multi-cancer early detection by artificial intelligence.

3067 Background: Early cancer detection is key to reducing cancer deaths. Unfortunately, many established cancer screening technologies are not suitable for use in low- and middle-income countries due to expenses, complexity, and dependency on extensive medical infrastructure. Therefore, a simple, affordable, efficient multi-cancer early detection test is a major unmet need. Methods: This study enrolled nearly 10,000 participants (1959 cancer cases and 7423 non-cancer cases) containing more than nine common cancer types. One tube of peripheral blood samples was collected from each participant and quantified a panel of seven selected protein tumor markers (PTMs) by a clinical common electrochemiluminescence immunoassay analyzer. A protein assay named OncoSeek was established using artificial intelligence to distinguish cancer from non-cancer cases by calculating the probability of cancer (POC) index based on the quantification results of 7 PTMs and clinical information including gender and age of the subjects. Then using another model to predict the possible affected tissue of origin (TOO) who has been detected with cancer signal. Results: In this study, we found that the conventional clinical method relied only on a single threshold for each protein tumor marker which would make a big problem that was when combining the result of those markers, the false positive rate would accumulate as the number of tests increased. Nevertheless, OncoSeek was empowered by artificial intelligence technology to significantly reduce the false positive rate, increasing the specificity from 56.9% (95% confidence interval (CI): 55.8% to 58.0%) to 92.9% (95% CI: 92.3% to 93.5%). In all cancer types sensitivity of the OncoSeek test was 51.7% (95% CI: 49.4% to 53.9%). The sensitivities ranged from 37.1% to 77.6% for the detection of the nine common cancer types (breast, colorectum, esophagus, liver, lung, lymphoma, ovary, pancreas, stomach), which account for ~59.2% of global cancer deaths annually. Furthermore, it has shown excellent sensitivity in several high-mortality cancer types for which there are a lack of routine screening tests in the clinic, such as the sensitivity of pancreatic cancer was 77.6% (95% CI: 69.3% to 84.6%). The overall accuracy of tissue of origin (TOO) prediction in true positives was 66.8%, which reduced the clinical diagnostic workup. Conclusions: In summary, this study supported that OncoSeek significantly outperforms the conventional clinical method, representing a novel blood-based test for multi-cancer early detection which is a non-invasive, easier, and efficient approach. Moreover, the accuracy of TOO of it which facilitates the follow-up diagnostic workup. As well as this method is affordable (the cost of the test is less than $25) and requires nothing more than a blood draw at the screening sites, which makes it more practical in low- and middle-income countries.

A label-free electrochemical immunosensor based on 11-mercaptoundecanoic acid grafted chitosan and poly(N-methylaniline) for the detection of carcinoembryonic antigen

Carcinoembryonic antigen (CEA) is a cancer marker used for monitoring cancer treatment. Herein, a label-free electrochemical immunosensor for determining CEA concentration composed of the thiolated chitosan (tCHI) and the doped poly(N-methylaniline) (dPNMA) is proposed. The tCHI served as a support matrix for the immobilization of CEA antibodies (anti-CEA) and was prepared by using 11-mercaptoundecanoic acid (MUA) as a grafting agent on chitosan (CHI). The excellent electrical conductivity of the dPNMA was utilized as an electron transfer layer for the proposed immunosensor. The successful preparation of the tCHI was confirmed by the attenuated-total reflection Fourier transform spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were used to illustrate the performance of the proposed immunosensor. The determination of CEA concentration was relied on the decrease in the DPV current response with increasing CEA concentration from the creation of the antigen–antibody immunocomplex. The proposed immunosensor demonstrated a broad concentration range of 0.01 to 30 ng mL−1 with a low limit of detection (LOD) of 0.01 ng mL−1. In addition, the present sensor exhibited excellent selectivity, reproducibility, and long-term stability, suggesting its potential use to determine CEA in clinical immunoassay.

Evaluation of hemolysis, lipemia, and icterus interference with common clinical immunoassays.

Hemolysis, icterus, and lipemia (HIL) are common sources of endogenous interference in clinical laboratory testing. Defining the threshold of interference for immunoassays enables appropriate reporting of their results when they are affected by HIL. Pools of residual patient serum samples were spiked with a known amount of interferent to create samples with varying concentrations of hemolysate, bilirubin, and Intralipid that mimicked the effects of endogenous HIL.Samples were analysed on the Alinity i analyser (Abbott Diagnostics) for more than 25 immunoassays. The average recovery relative to the non-spiked sample was calculated for each interference level and was compared to a predefined allowable bias. C-peptide, estradiol, serum folate, free T4, homocysteine, insulin, and vitamin B12 were found to be affected by hemolysis, at hemoglobin concentrations between 0.3 to 20g/L. Immunoassays for BNP, estradiol, free T3, andhomocysteine were affected by icterus at conjugated bilirubin concentrations between 50 to 1,044μmol/L. BNP, serum folate, and homocysteine were affected by Intralipid with measured triglyceride concentrations between 0.8 to 10mmol/L. Lastly, serological immunoassays for HIV and hepatitis A, B and C were also affected by interferences. Immunoassays are impacted by varying degrees of HIL interference. Some measurands, in the presence of interference, are affected in a manner not previously indicated. The data presented herein provide anindependent evaluation of HIL thresholds and will be ofaid to resource-limited clinical laboratories that are unable to internally verify endogenous interferences when implementing the Alinity i analyser.

A non-metallic SERS-based immunoassay founded by light-harvesting effect and strengthened chemical enhancement.

Owing to its promising biocompatibility and reliable sensitivity, semiconductor-guided surface-enhanced Raman scattering (SERS) technology has aroused widespread concern in clinical immunoassays. Herein, the well-improved light capture capability of MoS2 with a novel three-dimensional (3D) flower-like morphology was combined with the synergistic chemical enhancement from a MoS2@red phosphorus (RP) hybrid system, facilitating an attractive non-metallic SERS-based detection of ferritin in serum. Owing to the remarkable enhancement factors of both the immunoprobe and immunosubstrate, which were comparable to noble metal, an extremely low limit detection of 11.5 pg mL-1 was achieved in the absence of fluorescence interference. In particular, the trace ferritin in the clinical serum sample was successfully monitored, demonstrating superior sensitivity to the traditional chemiluminescent method. Overall, this study convincingly revealed the feasibility and reliability of SERS-based immunoassays induced by biocompatible semiconductors, which has opened a new way to implement the detection and tracking of biomarkers in the human body.

Clinicopathological and genetic features of primary cardiac angiosarcoma

This article mainly discusses the clinicopathological and laboratory characteristics of cardiac angiosarcoma, makes a differential diagnosis of the basic condition of primary cardiac angiosarcoma, and improves the understanding of primary cardiac angiosarcoma, this article studies the clinical data, pathology and immunoassay results of three patients with cardiac angiosarcoma, discusses the clinicopathological features and differential diagnosis of cardiac primary angiosarcoma, and improves the understanding of the tumor. Methods The clinical data, pathomorphology and immunohistochemical results of 3 cases of angiosarcoma in the heart were analyzed retrospectively. Most of the patients had clinical symptoms such as chest pain and dyspnea at the initial stage of the disease. Through the examination of the tumor tissue, it was observed that the cell structure was fusiform and oval, and there was necrosis in the vascular lumen.

Use of a Lean Six Sigma approach to investigate excessive quality control (QC) material use and resulting costs

PurposeThe Eastern Health Clinical Biochemistry Laboratories cater to the province of Newfoundland and Labrador. Over the last ten years, a significant increase in annual expenses on quality control material and calibrator purchases was observed. Two major Clinical Chemistry Laboratories at the Health Sciences Centre (HSC) and St. Clare’s Mercy Hospital (STC), St. John’s, work as referral centers for the province. The study’s design was based on the Six Sigma DMAIC (Define, Measure, Analyze, Improve, and Control) process and involved tests performed on ten automated Abbott Clinical Chemistry (CC) and Immunoassay (IA) analyzers. The cost of purchasing the QC material from Bio-Rad and Randox had increased due to defective QC and analyzer test assignment process design. The processes were modified. An Individualized Quality Control Plan (IQCP) was developed. ResultsModification in quality control processes helped in bringing down the cost and usage of both QC and calibrators. The cost and usage of individual control material were reduced by 25 to 52% depending on the type of quality control. Total annual expenditure on the purchase of different QC materials before modification was estimated as CAD 346,395(2019) which was reduced to CAD 255,267 with annual savings of 91,128 CAD (26%) after modification (2020). The average usage reduction for various calibrators was 40% with the highest reduction in the use of urine calibrators. The annual cost of calibrators was reduced from CAD 30,568.42 (2019-20) to CAD 17,517 (2020-21) with the saving of approximately 13,051 Canadian dollars (43 %) for the laboratory. ConclusionsThere is a constant compulsion in every industry to manage costs. Implementation of Lean and Six Sigma methodology in removing Muda of high costs in a Clinical Chemistry Laboratory is the most warranted strategy in developing a cost-effective laboratory framework.

An impedimetric immunosensor based on PAMAM decorated electrospun polystyrene fibers for detection of interleukin-10 cytokine

• Polystyrene (PS) fibers were electrospun and modified by air plasma for their further decoration with PAMAM. • The fabricated three-dimensional (3-D) architecture was employed as the transducer in an impedimetric immunosensor. • An LOD of 0.3 ng/mL of AgIL-10 was obtained. • Detecting AgIL-10 in artificial saliva (AS) as a complex medium was likewise satisfactory. Cytokine storms are known as the uncontrolled overproduction of inflammatory cytokines that can be produced by a variety of viral or non-infectious disorders and inflict significant damage to many organs. Interleukin-10 (IL-10) is an anti-inflammatory cytokine, and rapid detection of its levels in serum and saliva is important for many diseases, including severe COVID-19 patients. In this study, Polystyrene (PS) fibers were electrospun over a gold electrode and modified by air plasma to allow their further decoration with polyamidoamine (PAMAM) dendritic polymer for providing many active sites on the fiber surface. The fabricated three-dimensional (3-D) architecture was employed as a platform in an impedimetric immunosensor for the quantitative detection of interleukin-10 cytokine (AgIL-10). Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), contact angle measurements, fluorescence microscopy, UV–vis spectroscopy, and electrochemical methods including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterized the proposed electrospun fiber-based platform and electrochemical immunosensor. The PAMAM properties increased not only the amperometric response to the ferro/ferri cyanide redox probe, of the modified gold electrode but also the active surface area available for covalently binding of anti-IL-10 capture antibody, resulting in the sensitive detection of AgIL-10 in the concentration range of (1-50 pg/mL) in phosphate buffer saline (PBS) with a limit of detection (LOD) of 1 pg/mL. The immunosensor's performance in detecting AgIL-10 in artificial saliva (AS) as a complex medium was likewise satisfactory. This immunosensor provides a new opportunity for clinical immunoassays thanks to its great sensitivity, selectivity, and stability.

P079Etonogestrel contraceptive implant users can experience breakthrough ovulation with only two weeks of exposure to a strong cyp3a inducer

<h3>Objectives</h3> Rifampin is a strong CYP3A inducer and the gold standard for evaluating CYP3A-mediated drug-drug interactions per the US Food and Drug Administration. We hypothesized that even a short course (two weeks) of exposure would lead to breakthrough ovulation-mediated changes in endogenous estradiol (E2) and progesterone (P4) concentrations among etonogestrel (ENG) implant users. <h3>Methods</h3> We enrolled healthy people using ENG implants for 12–36 months. We measured baseline serum concentrations of E2 and P4 as surrogate biomarkers for ovulation suppression using clinical chemiluminescent immunoassays. After two weeks of rifampin 600 mg daily, we repeated E2 and P4 measurements. We determined breakthrough ovulation based on pre-exposure P4 3.0ng/mL with concurrent rise in post-treatment E2. <h3>Results</h3> Fifteen participants completed all study procedures. Participants' median age was 28.2 (range, 21.8–34.1), median BMI was 25.2 kg/m2 (range, 18.9–37.3), and median duration of implant use was 22 months (range, 12–32). At baseline, median E2 concentrations were 73 pg/mL (range, 32–686) and median P4 concentrations were 0.3 ng/mL (range, 0.2–6.1). After concomitant rifampin, median E2 concentrations were 201 pg/mL (range, 59–951) and median P4 concentrations were 0.4 ng/mL (range, 0.2–15.8). Serum E2 concentrations significantly increased with rifampin exposure (p=0.003, paired Wilcoxon signed rank test), but the increases in serum P4 concentrations were not statistically significant (p=0.185). Three participants (20%) experienced breakthrough ovulation with the following P4 changes: 0.3>5.0, 0.8>7.3, 0.5>15.8 (pre>post; ng/mL). <h3>Conclusions</h3> With only a short exposure to a strong CYP3A inducer, ENG implant users experienced clinically significant changes in hormone biomarkers indicative of waning follicular development and ovulation suppression.

Postoperative Prognostic Predictors of Bile Duct Cancers: Clinical Analysis and Immunoassays of Tissue Microarrays.

Cholangiocarcinoma frequently recurs even after curative resection. Expression levels of proteins such as epidermal growth factor receptor (EGFR), Snail, epithelial cadherin (E-cadherin), and interleukin-6 (IL-6) examined by immunohistochemistry have been studied as potential prognostic factors for cholangiocarcinoma. The aim of this study was to investigate significant factors affecting the prognosis of resectable cholangiocarcinoma. Ninety-one patients who underwent surgical resection at Samsung Medical Center for cholangiocarcinoma from 1995 to 2013 were included in this study. Expression levels of E-cadherin, Snail, IL-6, membranous EGFR, and cytoplasmic EGFR were analyzed by immunohistochemistry using tissue microarray blocks made from surgical specimens. Patients with high levels of membranous EGFR in tissue microarrays had significantly shorter overall survival (OS) and disease-free survival (DFS): high membranous EGFR (score 0-2) 38.0 months versus low membranous EGFR (score 3) 14.4 months (p=0.008) and high membranous EGFR (score 0-2) 23.2 months versus low membranous EGFR (score 3) 6.1 months (p=0.004), respectively. On the other hand, E-cadherin, Snail, cytoplasmic EGFR, and IL-6 did not show significant association with OS or DFS. Patients with distant metastasis had significantly higher IL-6 levels than those with locoregional recurrence (p=0.01). This study showed that overexpression of membranous EGFR was significantly associated with shorter OS and DFS in surgically resected bile duct cancer patients. In addition, higher IL-6 expression was a predictive marker for recurrence in cholangiocarcinoma patients with distant organ metastasis after surgical resection.

Measurement of D-dimer in cerebrospinal fluid using a luminescent oxygen channeling immunoassay.

Measurement of D-dimer in cerebrospinal fluid (CSF) allows insight into coagulation system activation in the central nervous system and can be utilized to monitor intracranial hemorrhage as well as acute phase processes beyond hemostasis in inflammatory and neoplastic diseases. So far, the measurability of D-dimer in low and very low concentrations in CSF was limited in conventional immunoassays. Novel high-sensitivity chemiluminescent immunoassays such as the luminescent oxygen channeling immunoassay (LOCI®) are getting increasingly available but have not been validated in CSF. The aim of this study was to investigate the accuracy and linearity of the LOCI® in assessing D-dimer in CSF. INNOVANCE LOCI hs D-dimer reagent cartridge was used for the measurement of D-dimer in CSF of patients with different neurological diseases. For the evaluation of linearity, dilution series were performed in a pooled CSF sample with the determination of intra-assay precision (CV, coefficient of variation) in 3 individual samples with 20 replicates. Furthermore, D-dimer concentrations measured by LOCI® were compared with the respective results of a routinely available clinical latex-enhanced immunoassay (HemosiIL D-Dimer HS 500). Linear regression analysis of the LOCI® method revealed a r 2 of 1.00 (p < 0.001) with a regression coefficient B of 1.012 ± 0.003 (CI: 1.005-1.019, p < 0.001) and an intercept of -1.475 ± 1.309 (CI: -4.493 to 1.543); the median intra-assay CV was 0.69% (range: 0.68-0.75). In total, 185 CSF samples were measured by LOCI® technology, showing a mean concentration of 204.84 ± 2,214.93 ng/ml. D-dimer concentration between LOCI and latex-enhanced immunoassay differed by a factor of 10.6 ± 13.6 on average with a maximum deviation by a factor of 61.3; the maximum deviation was found at low concentrations. D-dimer in CSF of patients with neurological disease can be reliably measured by the LOCI® method with high linearity and accuracy at low concentrations.

Unquantifiably low aldosterone concentrations are prevalent in hospitalised COVID-19 patients but may not be revealed by chemiluminescent immunoassay.

ObjectivePrevious studies have reported conflicting findings regarding aldosterone levels in patients hospitalised with COVID-19. We therefore used the gold-standard technique of liquid chromatography–tandem mass spectrometry (LCMSMS) to address this uncertainty.DesignAll patients admitted to Cambridge University Hospitals with COVID-19 between 10 March 2020 and 13 May 2021, and in whom a stored blood sample was available for analysis, were eligible for inclusion.MethodsAldosterone was measured by LCMSMS and by immunoassay; cortisol and renin were determined by immunoassay.ResultsUsing LCMSMS, aldosterone was below the limit of detection (<70 pmol/L) in 74 (58.7%) patients. Importantly, this finding was discordant with results obtained using a commonly employed clinical immunoassay (Diasorin LIAISON®), which over-estimated aldosterone compared to the LCMSMS assay (intercept 14.1 (95% CI −34.4 to 54.1) + slope 3.16 (95% CI 2.09–4.15) pmol/L). The magnitude of this discrepancy did not clearly correlate with markers of kidney or liver function. Solvent extraction prior to immunoassay improved the agreement between methods (intercept −14.9 (95% CI −31.9 to −4.3) and slope 1.0 (95% CI 0.89–1.02) pmol/L) suggesting the presence of a water-soluble metabolite causing interference in the direct immunoassay. We also replicated a previous finding that blood cortisol concentrations were often increased, with increased mortality in the group with serum cortisol levels > 744 nmol/L (P = 0.005).ConclusionWhen measured by LCMSMS, aldosterone was found to be profoundly low in a significant proportion of patients with COVID-19 at the time of hospital admission. This has likely not been detected previously due to high levels of interference with immunoassays in patients with COVID-19, and this merits further prospective investigation.