bluuebunny/crossref_metadata_2025_split huggingface dataset:
B-009 Accuracy Validation of Elecsys HBsAg II Quant Assay to Resolve Equivocal Qualitative HBsAg Results
Authors: Kim D , Lee J , Park J , Kim N , Lee S , Cho Y 
Published: September 2023

Abstract

Background
There are reports of false qualitative HBsAg results because of several causes, such as samples with low HBsAg concentrations that may produce false positives. The main aims of this study are to validate the analytical accuracy and operational cutoff value of the Elecsys HBsAg II Quant assay. The secondary goal is to assess the role of the Elecsys assay in resolving equivocal quali-tative HBsAg results compared to those of the qualitative HBsAg assay in the medical laboratory.

Methods
The limit of blank (LoB), limit of detection (LOD), limit of quantification (LoQ), and linearity were first estimated to validate the analytical accuracy of the Elecsys HBsAg II Quant assay. To validate the linearity of the assay according to CLSI EP06-A, five expected diluted as-sayed samples, including 0.01 (dilution ratio of minimum to maximum value = 4:0), 11.90 (3:1), 23.70 (2:2), 35.50 (1:3), and 47.30 IU/mL (0:4), were prepared within the concentration of the WHO 3rd IS (47.3 IU/mL) and measured for five replicates at each level. A total of 449 serum samples showing initial equivocal results (1–50 index) were evaluated by El-ecsys HBsAg II Quant and ADVIA Centaur HBsAg II assays.

Results
The LoQ of the assay was determined to be 0.050 IU/mL, as provided by the manufacturer. The Kappa agreement between the two assays was almost perfect at 0.9669 despite the seven dis-cordant results. The ROC curve analysis of this assay showed an AUC of 0.965 (P &lt; 0.001), with a specificity of 100% and sensitivity of 24.15% at the new COI value of 5.42. Those HBsAg samples with index values &lt;5.42 need to be confirmed with an approved method or via additional HBV marker assays without further duplicate tests. The Kappa agreement between the two assays was almost perfect at 0.9669 despite the seven discordant results (three by ADVIA Centaur HBsAg II Negative and Elecsys HBsAg II Quant Positive; four by ADVIA Centaur HBsAg II Positive and Elecsys HBsAg II Quant Negative). The concordance rate and accuracy of the ADVIA Centaur HBsAg II as-say relative to the Elecsys HBsAg II Quant assay from the confirmed results were 98.44% and 98.55%, respectively, when the HBsAg seroprevalence of 5.3% from the Western Pa-cific region, including South Korea, was applied.

Conclusion
We confirm that the Elecsys HBsAg II Quant assay is a very accurate and sensitive for HBV infec-tion and recommend it as an alternative confirmatory HBsAg assay for resolving equivocal qualitative HBsAg results.
B-013 Association Between Laboratory Parameters Analysis and Clinical Severity in Patients With Coronavirus Disease (Covid 19) at Hospital Universitario Fundación Santa Fe
Authors: Martinez Nieto O , Gonzalez H A , Saavedra Andrade C E , Bertel Rodriguez D M , Rodriguez Urrego P A , Vargas Gallo J P 
Published: September 2023

Abstract

Background
Clinical management of COVID-19 disease was challenging. Laboratory parameters could be useful to classify patients in risk scores and probability to progress to a severe stage at the emergency room. This study aims to determine the association between laboratory parameters of COVID-19 patients and clinical disease severity to provide applicable information to improved treatment strategies. Thus, we described the laboratory findings that can work as a predictive marker of severity, in a cohort of patients form our institution from Colombia diagnosticated with COVID-19 during a period of one year.

Methods
This retrospective cohort descriptive study was conducted at one quaternary hospital at Bogota Colombia, where laboratory parameters on peripheric blood samples in 298participants with COVID-19 diagnosis were evaluated. For comparison between two groups’ data, the chi-square and Mann-Whitney U test were used. For correlation between variable a Spearman and a Kruskal Wallis test were performed as data didn’t normal distribution. A P-value lower than 0.05 was considered statistically significant in all analyses.

Results
Primary outcomes shown significant correlation between more severe disease and interleukin IL-6 elevation, by the Kruskal Wallis test. Lower counts of lymphocytes percent, ferritin, fibrinogen, neutrophils, basophils and coagulation factors were found to be associated with severe disease (P &lt; 0.0001). Creatinine, D dimer, LDH, WBC count, creatinine and erythrosedimentation were significantly higher and were correlated with more severe disease on scores (P &lt; 0.001). Higher levels on PCR parameters were associated with severe disease (P &lt; 0.001).

Conclusion
Laboratory parameters such as IL-6 can be used as a severity marker in order to help physicians find both adequate treatment and hospitalization location of COVID-19 patients. This information can be used to manage future pandemics, and to evaluate complementary strategies that should be efficient on epidemic management and patient care having an impact on public health, mortality rates and hospitality capacity
B-027 Adaptation of Neonatal Dried Blood Spot Assays for Use on Automated Microplate Instruments
Authors: Van Slooten G 
Published: September 2023

Abstract

Background
Newborn screening (NBS) is routinely conducted to identify various inherited metabolic disorders which can affect a child’s long-term health or survival. The assay methods used include enzyme-linked immunosorbent assays (ELISA) as well as enzymatic biochemical assays. Dried blood spots (DBS) prepared by applying whole blood to filter paper cards are typically used as the sample for these screening assays. In this study we have adapted an openly programmable automated ELISA processing instrument to perform these types of assays with a high level of accuracy and precision.

Method
The Awareness Technology (Palm City, FL) ChemWell-2 instrument was chosen for this study. This instrument is a two plate ELISA processing system which has the capability of performing the DBS extraction in an uncoated round bottom 96-well microplate and transferring a small volume of extracted sample to be assayed to a second flat bottom 96-well microplate. The following enzymatic assay kits manufactured by ZenTech (Liège, Belgium) were used in this study: total galactose, phenylalanine, glucose-6-phosphate dehydrogenase (G-6-PD) and biotinidase.

Results
In order to evaluate the assay performance controls and additional standard DBS were run as samples. Three to four different sample concentration levels were run four to five times in each assay. The runs were repeated 4 times each to determine inter-assay (between run) precision. The results are summarized in the table below:

Conclusion
Enzymatic NBS methods for total galactose, phenylalanine, G-6-PD and biotinidase including the DBS sample extraction step can be processed with clinically useful accuracy and precision using the Awareness Technology ChemWell-2 automated analyzer.
B-040 Performance Evaluation of Five Reproductive Endocrinology Assays on the Atellica CI 1900 Analyzer
Authors: Zhang H , Frenna J , Halik L , Ozgen N , Quintanilla M , Rhea-McManus J , Leipold H 
Published: September 2023

Abstract

Background
The Atellica® CI 1900 Analyzer is an automated, mid-throughput, integrated chemistry and immunoassay analyzer utilizing both Atellica CH and Atellica IM assays. This study was designed to evaluate the analytical performance of the Atellica IM Luteinizing Hormone (LH), Progesterone (PRGE), Follicle Stimulating Hormone (FSH), Prolactin (PRL), and Total hCG (ThCG) assays* on the Atellica CI 1900 Analyzer.

Methods
The Atellica CI 1900 LH, PRGE, FSH, PRL, and ThCG assays use the same reagents and calibrators as the comparable Atellica IM assays. Precision and method comparison (MC) studies were used as performance indicators for the Atellica CI 1900 Analyzer. Precision studies were performed according to CLSI EP05-A3 using quality control material and native and contrived human serum samples. One aliquot of each sample pool was tested in duplicate in two runs per day ≥2 hours apart on each analyzer for ≥20 days with one reagent lot on two systems. MC studies were performed according to CLSI EP09-A3. Individual native human serum samples were analyzed using the Atellica IM assays on both the Atellica IM and Atellica CI 1900 Analyzers.

Results
Representative precision and MC results are listed for each assay in the table. Over the five assays tested, repeatability and within-lab %CVs were &lt;7% and &lt;13.5%, respectively. Slopes determined by the Deming linear regression model were approximately equal to 1.

Conclusion
Evaluation of the Atellica IM LH, PRGE, FSH, PRL, and ThCG assays using the Atellica CI 1900 Analyzer demonstrated good precision and equivalent performance compared to the same assays on the Atellica IM Analyzer.
*The products/features mentioned here are not commercially available in all countries. Their future availability cannot be guaranteed.
B-041 Evaluation of a Nuclear Magnetic Resonance Spectroscopy-Based Method for Estimating Glomerular Filtration Rate Using Creatinine, Cystatin C, Myo-Inositol, and Valine
Authors: Branson L , Southard D , Hadder B , Katrangi W , Alturkmani R 
Published: September 2023

Abstract

Background
Timely and accurate monitoring of renal dysfunction is critical for patients with chronic kidney disease (CKD). Most equations currently used for estimating glomerular filtration rate (GFR) incorporate serum levels of creatinine and/or cystatin C. Here, we evaluate a recently introduced method for estimating GFR that uses nuclear magnetic resonance spectroscopy (NMR) to measure creatinine, myo-inositol, and valine in combination with cystatin C measured by immunoassay, and patient’s age and sex (eGFRNMR).

Methods
Serum creatinine, valine, and myo-inositol measurements were performed simultaneously by an NMR assay on a Bruker Avance III HD 600 MHz NMR instrument (Bruker Corporation, MA). Cystatin C testing was performed using an immunoturbidimetric assay (Diazyme Laboratories, CA) on a cobas 8000 analyzer (Roche Diagnostics, IN). Within-run and between-day precision studies were performed across 5 days. Method comparison was carried out by testing 86 split serum samples from adult individuals against the numares AG GFR (NMR) assay. Of the 86 samples, 20 were spiked with various concentrations of creatinine, myo-inositol, and valine to reach a wide range of GFR results. An additional method comparison study was performed against Mayo Clinic Laboratories (Rochester, MN) on 59 serum samples from adult patients that had already been tested using the same assay. Measured GFR (mGFR) was also performed on these patients by Mayo Clinic Laboratories using urinary iothalamate clearance.

Results
Within-run and between-day coefficients of variation (%CV) for eGFRNMR did not exceed 6%. The eGFRNMR measurement range was confirmed at 10 to 157 mL/min/1.73 m2 based on verified analytical measurement ranges of creatinine (0.28–9.8 mg/dL), myo-inositol (39–430 µmol/L), and valine (30–1250 µmol/L). Method comparison studies against both numares AG and Mayo Clinic Laboratories demonstrated excellent concordance (r2 = 0.95 and r2 = 0.97, respectively) and minimal bias (4.1% and −0.3%, respectively) with results ranging from 21 to 157 mL/min/1.73 m2. When the 59 patients who had their GFR measured were staged by their mGFR results according to the CKD classification ranges of &lt;15, 15–29, 30–44, 45–59, 60–89, and ≥90 mL/min/1.73 m2, eGFRNMR showed higher classification concordance with mGFR (69%) than the CKD-EPI 2021 creatinine-cystatin C equation (63%).

Conclusion
Our evaluation confirms the excellent analytical and clinical performance of the recently introduced eGFRNMR assay, supporting its integration into clinical practice for improved estimation of GFR.
B-043 Thermal Evaluation and Field Study of Labcorp TrueThermTMpackaging System for Protecting Sub-Milliliter Blood Samples
Authors: Schaff U , Iacovetti G , Collier B , Setzer S , Peevler M , Ragar J , Brandon W , Chappell M , Grant R P , Sommer G J 
Published: September 2023

Abstract

Background
Many diagnostic assays require temperature-controlled sample storage and shipment to ensure accuracy. Here we present, the Labcorp TrueTherm, designed for thermal-controlled shipment of small volume blood samples. The reusable TrueTherm combines a stainless steel vacuum bottle with a custom internal cold pack and insulating stopper. Users refrigerate the cold pack to protect against warm or cold temperature excursions. The whole system is relatively compact, measuring about 10in (25cm) in length, 3 inches (8cm) in diameter, and 2.5 pounds (1kg) in weight.

Methods
In order to evaluate thermal performance, the TrueTherm system was exposed to both ISTA-7D summer and winter conditions and internal temperature was recorded for 96hrs. Subsequently, venous blood samples were collected from n = 40 subjects, and immediately aliquoted into BD SST (Serum separator) Microtainers®. For each subject, sub-samples were subjected to centrifugal separation (provided by the Labcorp TrueSpinTM battery-powered centrifuge), serum removal, and 24hr insulated shipping on ice packs compared to a variety of 72hr cross-country shipping conditions with and without centrifugal separation and with and without insulated packaging (including TrueTherm) during August 2022.

Results
TrueTherm maintained temperature between 2 and 20C for 72hrs under simulated summer and winter conditions. Under actual cross-country summer commercial shipping conditions, both centrifugal separation and thermal control via TrueTherm expanded the number of valid analytes compared to unprotected whole blood (see Table 1).

Conclusion
The results suggest that TrueTherm is an effective system for protecting small blood samples from thermal extremes during extended shipping. Portable thermal moderation was complimentary with portable centrifugal separation to maximize stability of common analytes.
B-058 Development and Evaluation of the Assay for Detection of Human Specific IgE Against Animal Dander Allergens on a Fully Automated Chemiluminescence Immunoassay Platform—Autolumo® A2000 Plus
Authors: Rezaei S , Yang X , Xi I , Zhao D , Han J , Zhu K , Li Z , Lee C 
Published: September 2023

Abstract

Background
The detection of specific IgE is a key method for diagnosing allergic diseases. An accurate, user friendly and cost-effective way to clinically diagnosing allergies is beneficial for the patients. Our detection kit together with the Autolumo A2000 Plus chemiluminescence fully automated platform provide a new and more effective (40 minutes) way for detection of specific IgE with simple operation, high sensitivity and specificity.

Methods
The Animal Dander Allergen Mix Assay kit detects specific IgE against cat dander (E1), horse dander (E3), cow dander (E4) and dog dander (E5). Performance evaluation of the animal dander mix, E1, E3, E4 and E5 assay kits for the detection of specific IgE in serum was performed on our automated chemiluminescence platform (Autolumo A2000 Plus) and compared to a well-characterized platform (ImmunoCAP, Phadia). During detection, magnetic particle suspension, antigen solution, patient sample, and enzyme conjugate were added sequentially. A streptavidin-biotinylated antigen-sIgE antibody-anti-IgE-HRP conjugate complex is formed, wherein the amount of the anti-IgE-HRP conjugate is positively correlated to the amount of sIgE antibodies in the patient sample. After the substrate is added, the HRP catalyze the chemical reaction to generate a recordable signal in the form of light. The intensities of the light were obtained by using a chemiluminescence quantitative analyzer, and the standard curve was generated according to the 7-point calibration, and then the sIgE antibody concentrations in the serum sample were analyzed. The overall agreement, method comparison, precision, linearity, and stability of our mixed and single assay kits were evaluated using serum samples (n &gt; 140) that had been characterized with Phadia.

Results
The overall agreement for the animal dander mix assay is 91.84%, with the average intra-run and inter-run precision to be 1.97% and 4.21% respectively. The limit of blank (LoB) and limit of detection (LoD) for the animal dander mix assay is 0.019 kU/L and 0.045 kU/L respectively. The sensitivity for our single E1, E3, E4, and E5 assays are 97%, 85.6%, 70.8%, and 80.2%, respectively. All single assays have a specificity &gt;90%, total precision &lt;5% CV, and a linearity with R2 &gt; 0.999. The LoB, LoD and recommended LoQ for all single assays are 0.019 kU/L, 0.037 kU/L, and 0.1 kU/L respectively. The average signal drifts after 10 days incubation in 37C is less than 10% indicating the assays are stable.

Conclusion
Autolumo A2000 Plus is a fully automated chemiluminescence Immunoassay platform that provides accurate and cost-effective screening for allergy diagnostics with excellent overall agreement, precision, and stability.
B-060 Measurement of Infliximab Clearance using a Bayesian Forecasting Tool and Impact of Albumin and Immunization Status During Maintenance Treatment of Inflammatory Bowel Disease
Authors: McLachlan O , Schwalbe M , McFarland J , Pham D , Hughes P , Dervieux T 
Published: September 2023

Abstract

Background
Accelerated Clearance of monoclonal antibodies such as Infliximab (IFX) is a known predictive factor of pharmacokinetic origin that associates with poor outcome in patients with Inflammatory bowel diseases (IBD). We have implemented a Bayesian forecasting tool for IFX (PredictrPK® IFX) and calculated its Clearance. Our objective was to evaluate the impact of Albumin (ALB) and antibodies to IFX (ATI) on Clearance and exposure from patient specimens with IBD and submitted for testing in the routine clinical pharmacokinetic laboratory.

Methods
IFX concentration and ATI status were determined from serum using a homogenous mobility shift assay. Serum ALB concentration was determined using nephelometry. Clearance was estimated using inputted IFX concentration, ATI status, ALB, dose and interdose interval, and nonlinear mixed effect modeling with Bayesian priors. Patient specimens were collected anytime 20 days after the infusion and submitted for testing. Median Clearance (expressed as L/day) and estimated IFX trough concentrations by ATI status and lower Albumin levels (&lt;4.0 g/dL) was calculated. Statistical analysis consisted of nonparametric Mann-Whitney tests.

Results
The prevalence of ATI was 9.1% in this cohort of patient specimens. Median Clearance was 0.246 L/day (IQR: 0.191–0.323 L/day) and median IFX Trough concentration was 11.9 µg/mL (IQR: 6.5–19.9 µg/mL). ATI status associated with lower IFX Trough concentrations and higher Clearance (P &lt; 0.01). Lower ALB concentration regardless of ATI status also associated with lower IFX Trough concentrations (P &lt; 0.01). There was twofold higher Clearance and twelvefold lower IFX Trough concentration in the presence of ATI and lower ALB. Results are presented in Table 1.

Conclusion
The data are consistent with the notion that IFX immunization and lower ALB impact Clearance and exposure to IFX.
B-067 Performance Assessment of a Newly Developed Lateral Flow Assay for the Quantification of Faecal Pancreatic Elastase
Authors: Afonso J , Schneider M , Guschin D , Gerhold C , Ricken B 
Published: September 2023

Abstract

Background
Pancreatic exocrine insufficiency (PEI) can be defined as an insufficient secretion of pancreatic enzymes and bicarbonate to maintain a normal digestion (1). PEI is associated to fat malabsorption, weight loss and malnutrition-related complications. Due to its important role in the digestive process, as a proteolytic enzyme and the high stability of the enzyme during intestinal transit, fecal pancreatic elastase (fPELA) is an ideal biomarker for the assessment of pancreatic function in patients suffering from PEI. The aim of this work was to develop and optimize a new rapid test for the quantification of fPELA.

Methods
A quantitative lateral flow assay was designed for the selective measurement of elastase antigen concentrations from stool extracts. The BÜHLMANN Quantum Blue® fPELA is a sandwich immunoassay. A monoclonal detection antibody is conjugated to gold nanoparticles. Elastase present in the sample binds to this gold conjugate. A polyclonal capture antibody, highly specific for elastase, is immobilized on the analytical membrane and captures the complex of elastase bound to the anti-elastase gold conjugate, resulting in a coloring of the test line. The remaining free anti-elastase gold conjugate binds to the control line. The signal intensities of the test line and the control line are measured quantitatively by the Quantum Blue® Reader. Pancreatic elastase is quantified in extracts of human stool samples collected with the BÜHLMANN CALEX® Cap device. Several analytical studies, such as sensitivity, linearity, High Dose Hook Effect (HDHE), were performed during optimization phase to assess the performance of the assay. Moreover, a method comparison with the commercially available high throughput turbidimetric BÜHLMANN fPELA® turbo assay was also performed.

Results
Both analytical and clinical performance were evaluated. Preliminary results of the assay performance were obtained during the optimization phase. Analytical sensitivity was determined as 12.8 µg/g LoB, 16.6 µg/g LoD and 17.2 µg/g LoQ. The linearity evaluation revealed a linear range of 10 to 472 µg/g. No HDHE was observed in native samples up to 4000 µg/g. Method comparison of the new lateral flow assay with BÜHLMANN fPELA® turbo assay, with 80 clinical samples, revealed good analytical agreement with a slope of 1.04 (Passing-Bablok) and a bias at cutoff (200 µg/g) of 5.6%. Relative bias (Bland-Altman) of the two assays was 6.9%. Considering the turbidimetric assay as the reference method, the sensitivity and specificity were 92% and 83%, respectively.

Conclusion
The newly developed quantitative lateral flow assay, BÜHLMANN Quantum Blue® fPELA, is an accurate, non-invasive and rapid test to determine fPELA levels in fecal extracts. The lateral flow assay is an attractive alternative to ELISA with a turn-around time of only 15 minutes enabling patients’ management in a more patient near clinical environment.